Hindawi Publishing CorporationBioMed Research InternationalVolume 2013 Article ID 412379 12 pageshttpdxdoiorg1011552013412379

Clinical StudyEffectiveness of Green Tea in a Randomized Human CohortRelevance to Diabetes and Its Complications

Naushad Ali Toolsee1 Okezie I Aruoma2 Teeluck K Gunness3 Sudhir Kowlessur4

Venkatesh Dambala5 Fatima Murad6 Kreshna Googoolye7 Diana Daus8

Joseph Indelicato8 Philippe Rondeau9 Emmanuel Bourdon9 and Theeshan Bahorun1

1 ANDI Centre of Excellence for Biomedical and Biomaterials Research and Department of Biosciences University of MauritiusReduit Mauritius

2 School of Pharmacy and Biomedical Sciences American University of Health Sciences Signal Hill CA 90755 USA3 Cardiac Centre Sir Seewoosagur Ramgoolam National Hospital Pamplemousses Mauritius4Non-Communicable Diseases Unit Ministry of Health and Quality of Life Port Louis Mauritius5 Department of Biochemistry Apollo Bramwell Hospital Moka Mauritius6Centre for Clinical Research and Education Apollo Bramwell Hospital Moka Mauritius7Human Resource Development Council NG Tower Ebene Mauritius8Department of Occupational Therapy Touro College of Health Sciences Bay Shore NY 11706 USA9Groupe drsquoEtude sur lrsquoInflammation Chronique et lrsquoObesite Universite de La Reunion Plate-forme CYROI Saint Denis97400 La Reunion France

Correspondence should be addressed to Okezie I Aruoma oaruomaauhsedu andTheeshan Bahorun tbahorunuomacmu

Received 12 April 2013 Revised 17 July 2013 Accepted 7 August 2013

Academic Editor Yvonne F Heerkens

Copyright copy 2013 Naushad Ali Toolsee et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Epidemiological studies have argued that green tea could mitigate diabetes and its complications This study investigated thephytophenolic profile of Mauritian green tea and its antioxidant propensity The effect of green tea on the risk factors waist-hipratio glucose level arterial pressure antioxidant status and alanine aminotransferase (ALT) in prediabetics was assessed Theexperimental group consumed 3 cups of green tea daily for 14 weeks followed by a 2-week washout period The control groupfollowed a water regimen Green tea contained high level of phenolics related to its antioxidant power Green tea suppressed waist-hip ratio of women from a significant increase and suppressedmean arterial pressure ofmen andwomen from a significant decreaseafterweek 14 It reducedALT level inwomenby 130 (119875 lt 01)while increasing the antioxidant potential ofmen andwomen sera by27 (119875 lt 01) and 51 (119875 lt 01)The study timescalemay have been too short to enable demonstration of effects on fasting plasmaglucose and HbA1c outcomes Green tea regimen could form part of a healthy lifestyle that might ameliorate features of metabolicsyndrome and subsequent risks for diabetes and its complications This trial is registered with ClinicalTrialsgov NCT01248143

1 Introduction

Diabetes has been shown to be a chronic metabolic disorderof multiple aetiologies The socioeconomic suffering is enor-mous Diabetes characterized by a state of insulin deficiencythat leads to a rise in glycemia [1] is commonly classified asinsulin-dependent diabetes mellitus (type 1 an autoimmunediseasewhere120573-cells of the pancreas are affected by the bodyrsquosdefence system) and noninsulin-dependent diabetes mellitus

(type 2 a metabolic disorder characterized by insulin resis-tance and deficiency) Reactive radical species are formed viaa number of pathways during hyperglycemia [2ndash5] Undernormal glycemic condition glucose primarily undergoesglycolysis and oxidative phosphorylation whereas underhyperglycemic state glucose could swamp the glycolytic pro-cess and hinder glyceraldehyde catabolism thereby causingfructose-16-bisphosphate and glyceraldehyde-3-phosphateto be channelled to other pathways such as enolization and

2 BioMed Research International

120572-ketoaldehyde formation protein kinase C activation hex-osaminemetabolism sorbitolmetabolism dicarbonyl forma-tion and glycation These combined biochemical pathwaysplay a cardinal role in the pathogenesis of diabetes whosetherapeutic management is argued here to potentially benefitfrom adjunct inclusion of dietary biofactors in functionalbeverages [2 5]

The physiological effects of polyphenol-rich beverageshave continued to receive considerable attention as healthfuldietary sources of antioxidants [6 7] This growing body ofevidence advocates the role of green tea or its bioactive pol-yphenolic compounds in ameliorating features of metabolicsyndrome and subsequent risks for type 2 diabetes [8 9]Green tea contains important phytochemicals such as cat-echins gallic acid caffeic acid kaempferol myricetin andquercetin [10] These green tea polyphenols showed antiox-idant activities in vitro by scavenging reactive radical speciesand function indirectly as antioxidants through inhibition ofredox-sensitive transcription factors inhibition of ldquoprooxi-dantrdquo enzymes and induction of antioxidant enzymes [11 12]Several studies have shown that green tea controls glomerularfiltration rate lowers albuminuria attenuates hypertensionprevents free radical generation in cardiac myocytes andreduces renal advanced glycation end-product in diabeticnephropathy model rats [13ndash17] In this study the phytophe-nolic profiles of a green tea infusate were determined andits antioxidant potential was evaluated using a multiassayapproach The potential modulatory effects of green teaconsumption on some selected parameters including waist-hip ratio glucose level arterial pressure antioxidant statusalanine aminotransferase and lipid profiles were assessedover a defined period of time in individuals inclined todevelop type 2 diabetes

2 Materials and Methods

21 Reagents 221015840-Azobis(2-methylpropionamidine)dihydro-chloride (AAPH) was obtained from Sigma-Aldrich Inc (StLouis MO USA) Clinical biochemistry reagent kits werepurchased from Beckman Coulter Inc (Brea CA USA) andRandox Laboratories Ltd (Dublin UK)

22 Plant Material Camellia sinensis var sinensis (ChineseJat) was obtained as homogenous green tea bags (finishedproduct) from Bois Cheri Tea Estate (Bois Cheri Republicof Mauritius) The tea bag containing approximately 2 g ofgreen tea was manufactured on November 2010

23 Total Phenol Content Phenol was determined by themethod of Singleton and Rossi [18]

24 Total Flavonoid Content Flavonoid was determined bythe method of Lamaison and Carnet [19]

25 Total Proanthocyanidin Content Proanthocyanidin wasdetermined by the method of Porter et al [20]

26 High-Performance Liquid Chromatography

261 Sample Preparation One green tea bag was infused in100mL hot water (100∘C) for 6minutes as described byWanget al [21] The brew was cooled under running tap water andcentrifuged at 4000 rpm for 15 minutes at 25∘C For gallicacid (+)-catechin (minus)-epigallocatechin (minus)-epigallocatechingallate (minus)-epicatechin gallate procyanidin B2 and (minus)-epicatechin analyses the supernatant was mixed with abso-lute methanol in a 2 1 supernatant methanol vv ratio priorto HPLC analysis

Myricetin kaempferol and quercetin were identified andquantified in green tea infusate after acid hydrolysis offlavonol conjugates essentially as follows and using morinas internal standard the supernatant was mixed with 6MHCL in a 8 1 supernatant 6MHCL vv ratio and incubatedat 85∘C for 25 hours After cooling the hydrolysed greentea supernatant extract was taken up in absolute methanol(3 1 vv hydrolysed green tea extract absolute methanol)prior to HPLC analysis

262 Chromatographic Conditions HPLC analysis of thegreen tea infusate was carried out using a Hewlett Packard1100 series (Waldbronn Germany) liquid chromatographysystem equipped with a vacuum degasser quaternary pumpautosampler thermostated column compartment and diodearray detector After filtration (022120583m filter paper) (Mil-lipore Corporation Bedford USA) 60120583L of extract wasinjected into a Zorbax SB-C18 column (46mm internaldiameter times 250mm length 35 120583m pore size) (Agilent Tech-nologies CA USA) Elution with a flow rate of 07mLminat 35∘C was as follows 0ndash30min 0ndash10 B in A 30ndash50min10ndash15 B in A 50ndash60min 15ndash25 B in A 60ndash90min 25ndash100 B in A 90ndash100min 100ndash0 B in A (Solvent A ace-tonitrilewater 19 vv pH 25 Solvent B acetonitrilewater11 vv pH 25 adjusted with phosphoric acid) The diodearray detector was set at 280 nm for the quantitative determi-nation of gallic acid and flavan-3-ol derivatives and at 365 nmfor flavonol aglycones The identification and quantificationof these phenolics were determined from retention timesand peak areas in comparison with authentic standardsResults were expressed in appropriate standards (mg) percup (200mL) Green tea extracts were analysed in triplicateCalibrated graphs of authentic standards were preparedvia appropriate serial dilutions with methanol and filtered(022 120583m) before use Calibration graphs were obtained byplotting the peak area of authentic standards versus theirknown quantities (05ndash45120583g)

27 Sample Preparation for Antioxidant and Free Radical-Induced Hemolysis Assays Two grams of green tea (equiva-lent to 1 tea bag) were infused in 200mL hot water (100∘C)for 6 minutes The green tea brew was cooled under runningtap water and filtered through a 02 120583m nylon filter The brewwas diluted to generate different concentrations of green teaextracts (01mgmL to 10mgmL) for use in antioxidant andfree radical-induced hemolysis assays

BioMed Research International 3

271 Antioxidant Assays

(1) Superoxide Radical Scavenging Assay The superoxideanion radical scavenging activity of green tea was measuredaccording to Nishikimi et al [22] with slight modifications

(2) Nitric Oxide Radical Scavenging Assay The nitric oxideradical scavenging activity of green tea wasmeasured accord-ing to Garratt [23] with slight modifications

(3) 221015840-Azino-bis (3-Ethylbenzothiazoline-6-sulfonic Acid)Radical Scavenging AssayThe ABTS∙+ scavenging activity ofgreen tea was measured according to Henriquez et al [24]with slight modifications

(4) Ferric ReducingAntioxidant PowerAssayThe ferric reduc-ing activity of green tea was measured according to Benzieand Strain [25] with slight modifications

(5) 22-Diphenyl-1-picrylhydrazyl Radical Scavenging AssayThe DPPH scavenging activity of green tea was measuredaccording to Sharma and Bhat [26] with slight modifications

(6) Ferrous Ion Chelating Assay The ferrous ion chelatingactivity of green tea was assessed according to Stookey [27]with slight modifications

(7) Hypochlorous Acid Scavenging Assay The hypochlorousacid scavenging activity of green tea was assessed accordingto Wang et al [28] and Aruoma and Halliwell [29]

272 Free Radical-Induced Hemolysis Assay The antioxidantactivities of green tea extracts and human sera derived fromthe clinical trial were evaluated using an assay based on freeradical-induced hemolysis [30]

28 Clinical Trial

281 Subjects Three hundred prediabetic Mauritians whoparticipated in a 2009 nationwide survey that was organizedby the Non-Communicable Diseases Unit of the Ministryof Health and Quality of Life Republic of Mauritius wereselected for the randomized controlled clinical trial (Clinical-Trialsgov IdentifiermdashNCT01248143) The inclusion criteriawere individuals at risk of diabetes (fasting plasma glucoseranged from 110 to 126mgdLmeasured using the hexokinasemethod) age ranged from 35 to 65 years The exclusioncriteria were smokers or those who have stopped smoking 6months before the clinical trial daily alcoholic intake exceed-ing two standard drinks postmenopausal women receiv-ing hormone replacement therapy hypertensive patients(gt14090mmHg) The clinical trial was approved by theNational Ethics Committee of the Ministry of Health andQuality of Life Republic of Mauritius and endorsed bythe Institutional Review Board at Touro College of HealthSciences (Bay Shore NY USA) The study was conducted inaccordance with the guidelines of the Declaration of Helsinkiprinciples All subjects gave written informed consent beforeclinical trial enrolment

282 Trial Profile and Study Design The clinical trial wasconducted from November 2010 to March 2011 at the Car-diac Centre of the Sir Seewoosagur Ramgoolam NationalHospital Pamplemousses Republic of Mauritius over a 16-week period The experimental group (119899 = 65) consumedone cup of green tea infusate (1 green tea bag infused for6min in 200mL hot water without milk or sugar) threetimes a day before meals (breakfast lunch and dinner) for14 weeks followed by a 2-week washout period The controlgroup (119899 = 58) consumed an equivalent volume of warmwater during the 16-week period (Figure 1) The randomallocation sequence was generated by a qualified statisticianusing a random generator that takes into account an unbiasedage and gender distribution within each group A simplerandomization approach with blocking for gender was usedto allocate subjects into their respective groups Participantswere instructed to maintain their usual daily activities andtheir former diet during the clinical trial

283 Dietary Survey Questionnaires Participants were con-tacted twice a week via phone to remind them to keepa record of all food and beverages consumed during theclinical trial A questionnaire indicating food and beverageitems consumed daily during the three main meals wasissued to each participant and was collected duly filled afterblood sampling exerciseDietary information provided by theparticipants enabled the assessment of any possible changesin the diet during the clinical trial Descriptive statistics ofthese questionnaires were based on daily mean calorie indexand daily lipidfat ratio [31] observed during the 14-weekintervention period and the 2-week washout period

284 Anthropometry and Blood Pressure Anthropometricand blood pressure data were recorded for each participantHeight was measured to the nearest 05 cm without shoesusing a calibrated stadiometerWeight wasmeasured withoutshoes and excess clothing to the nearest 01 kg using acalibrated mechanical beam balance BMI was calculated asweight in kilograms divided by height in squaremetersWaistand hip circumference was measured to the nearest 05 cmusing a dressmakerrsquos measuring tape applied horizontallyWaist girth was measured at the midpoint between the iliaccrest and the lowermargin of the ribs Hip girth was recordedas the maximum circumference around the buttocks Waist-hip ratio was calculated as waist in cm divided by hip incm Blood pressure was measured on the right upper armin seated and supine position after resting for five minuteswith an automatic device (Automatic blood pressure monitorModel SEM-1 OmronHealthcare Company Singapore) Twomeasurements were taken with 1 minute interval betweenthem and the mean of the 2 measurements was calculatedThese blood pressure values were used to calculate meanarterial pressure using the standard formula 23 diastolicblood pressure + 13 systolic blood pressure

285 Sample Collection 20mL of bloodwas collected underthe guidance of physicians from each participant fastingfor at least 12 hours The blood was dispensed appropriately

4 BioMed Research International

145 declined to participate

155 randomly allocated to

Experimental group(male n = 40 female n = 37)

Control group(male n = 43 female n = 35)

Completed 16-week period(male n = 33 female n = 32) (male n = 30 female n = 28)

300 participants met inclusion criteria and were invited to participate in the clinical study

Green tea regimen1 cup of green tea 3 times a day before

meals for 14 weeks

Water regimen1 cup of warm water 3 times a day before

meals for 14 weeks

Washout period1 cup of warm water 3 times a day before

meals for 2 weeks1 cup of warm water 3 times a day before

meals for 2 weeks

intervention12 lost to followup or discontinued 12 lost to followup or discontinued

intervention

Washout period

Completed 16-week period

Figure 1 Flow diagram showing trial profile and study design

into EDTA-K3 tube sodium fluoride oxalate tube and plaintubes Biological samples were kept at 4∘C and transportedfor analysis to Apollo Bramwell Hospital Moka Republicof Mauritius Before conducting any assays all tubes werecentrifuged at 3000 rpm for 7min at 25∘C with the exceptionof EDTA-K3 tube Human sera from plain tubes were usedfor free radical-induced hemolysis and clinical biochemistryassay Whole blood from EDTA-K3 tubes and human plasmafrom sodiumfluoride oxalate tubeswere used only for clinicalbiochemistry assay

286 Clinical Biochemistry Assay Human sera obtainedfrom plain tubes were tested for total cholesterol LDL HDLtriglycerides urea albumin creatinine ferritin total antiox-idant status aminotransferase aspartate (AST) and ALTHuman plasma obtained from sodium fluoride oxalate tubeswere tested for glucose Whole blood from EDTA-K3 tubewas used to determine glycated haemoglobin Using stan-dardized methods the automated Beckman Coulter AU480analyzer was used to quantify all biomarkers except totalantioxidant status which was evaluated by RX Daytona ana-lyzer All clinical biochemistry assays were completed within24 h after sample collection Serum creatinine (nonisotopedilution mass spectrometry traceable) urea and albuminwere used to estimate glomerular filtration rate (eGFR) usingthe ldquomodification of diet in renal diseaserdquo (MDRD) formula[32]

29 Statistical Analysis Parametric and nonparametric vari-ables are expressed after omitting outliers as mean plusmn stan-dard deviation and median [interquartile range] respec-tively Simple regression analysis was performed to calculate

the dose-dependent relationship of green tea extracts indifferent antioxidant assays Data derived from antioxidantassays were fitted into appropriate regressionmodel [33] (lin-ear polynomial order 2 or polynomial order 3) that allowedus to determine AA

50 Statistical inference was carried out

after omitting outliers using MedCalc for Windows (version11600 Mariakerke Belgium) Significant differences overtime within each group were determined using pairedStudentrsquos 119905-test and where data was not normal the non-parametric alternative Wilcoxon test was used Significantdifferences over time between each group were determinedusing independent samples 119905-test and where data was notnormal the nonparametric alternative Mann-Whitney testwas used The level for establishing significant differenceswas set at 10 successively Statistical analyses were alsoperformed to calculate any significant correlations betweenindividual variables daily mean calorie index and dailylipidfat ratio Pearson or Spearman rank correlation coeffi-cient was used for normally or nonnormally distributed datasets respectively Correlation analyses between individualvariables daily mean calorie index and daily lipidfat ratiowere carried out separately on week 14 and washout data setswhereby gender stratified data were taken into account Allstatistical tests were two-tailed

3 Results

31 Phytophenolic Composition of Mauritian Green Tea TheMauritian green tea phytophenolic profile is shown inTable 1 The most prominent phytophenolics in an unhy-drolyzed Mauritian green tea infusate were ranked accord-ing to their quantity per cup (200mL) in the followingdecreasing order procyanidin B2 gt (minus)-epigallocatechin

BioMed Research International 5

Table 1 Mauritian green tea phytophenolic data

Phytophenolic of unhydrolyzed Mauritian green teamg per cup(200mL)

Total phenol 23513 plusmn 3089a

Total flavonoid 752 plusmn 097b

Total proanthocyanidin 789 plusmn 063b

Procyanidin B2 49692 plusmn 2008c

(minus)-Epigallocatechin gallate 23468 plusmn 1208d

(minus)-Epigallocatechin 20512 plusmn 2542e

(minus)-Epicatechin gallate 2846 plusmn 180f

(minus)-Epicatechin 2442 plusmn 208g

(+)-Catechin 1390 plusmn 220h

Gallic acid 166 plusmn 016i

Phytophenolics in hydrolyzed Mauritian green teamg per cup(200mL)

Quercetin 150 plusmn 016j

Myricetin 148 plusmn 014j

Kaempferol 090 plusmn 008k

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant dif-ferences between mean phytophenolic contents (119875 lt 005) Free flavonoidswere not detected in the green tea extract however after hydrolysis HPLCanalysis showed that quercetin kaempferol and myricetin were the mainflavonol aglycones present in the following decreasing order quercetin gtmyricetin gt kaempferol

gallate gt (minus)-epigallocatechin gt (minus)-epicatechin gallategt (minus)-epicatechin gt (+)-catechin gt gallic acid Procyanidin B2 wasfound to be the most important compound with 49692mgper cup (200mL) while gallic acid was least prominent(166mg per cup)

32 Antioxidant Capacities of Mauritian Green Tea Thegreen tea antioxidant profile was characterized using 7 inde-pendent assays (Table 2) at concentrations varying from01 to 1mgmL A concentration ranking order indicat-ing 50 antioxidant activity (AA

50) for the green tea ex-

tract in each antioxidant assay was established as followsABTS∙+ scavenging activity (001mgmL) gt ferric reduc-ing activity (004mgmL) gt nitric oxide scavenging activ-ity (030mgmL) gt Fe2+ chelating activity (033mgmL) gtHOCL scavenging activity (039mgmL) gt superoxide scav-enging activity (042mgmL) gt DPPH scavenging activity(052mgmL) The data showed that the Mauritian greentea extract had a higher predisposition (119875 lt 005) to theABTS∙+ radical than the DPPH radical It also revealed anonsignificant (119875 gt 005) sensitivity to hypochlorous acidand superoxide anion radical Moreover Mauritian green teahad a higher affinity (119875 lt 005) to reduce Fe3+ into Fe2+ thanto chelate Fe2+

33 Clinical Trial A randomized controlled clinical trialwas conducted on humans predisposed to type 2 diabetesAmong the 300 participants that met the inclusion criteria

Table 2 Antioxidant activities of Mauritian green tea using a mul-tiassay approach

Antioxidant assays AA50 (mgmL)ABTS radical scavenging assay 001 plusmn 0001a

FRAP assay 004 plusmn 001b

Nitric oxide radical scavenging assay 030 plusmn 001c

Ferrous ions chelating assay 033 plusmn 003cd

HOCL scavenging assay 039 plusmn 003de

Superoxide radical scavenging assay 042 plusmn 001e

DPPH radical scavenging assay 052 plusmn 001f

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant differ-ences between mean AA50 (119875 lt 005) AA50 was defined as Mauritian greentea concentration that revealed a 50 antioxidant activity

155 agreed to enrol in the clinical trial and theywere randomlyallocated into the experimental and control groupThe num-ber of participants at the end of the clinical trial was 123representing a 206 dropout from initial population sizeThe final experimental and control groups consisted of 65and 58 participants respectively No subject withdrew fromthe clinical trial due to discomfort or any adverse effectsassociated with the regimen The complied dietary surveyquestionnaires showed that the daily mean calorie index anddaily lipidfat ratio remained relatively constant for both theexperimental and control groups in the male and femalepopulation during the 14-week intervention period and the2-week washout period (Figures 2 and 3) No correlationanalyses between individual variables daily mean calorieindex and daily lipidfat ratio for any group or gender turnedout to be significant nor were there any consistency in thedirection of correlations

The data in Tables 3 and 4 define the anthropometricand biochemical characteristics measured at the beginningof the study at the end of the 14-week intervention periodand after the 2-weekwashout period During the clinical trialwaist-hip ratio an indicator of obesity increased significantly(119875 lt 01) in the female control group whereas the femaleexperimental group did not experience any change on week14Mean arterial pressure defined as the average arterial pres-sure during a single cardiac cycle decreased insignificantly onweek 14 as indicated by the experimental group whereas maleand female control groups endured a critical decline of 30(119875 lt 01) and 26 (119875 lt 01) respectively

Based on the findings set out in Table 3 male subjectsunder green tea regimen showed an insignificant reduction of30 in ferritin concentration after week 14 whereas in malecontrol group its concentration rose considerably by 392(119875 lt 01) Moreover the green tea regimen did not affect thefasting plasma glucose of subjects

eGFR used to diagnose and monitor kidney functionwas estimated using the 6-variable MDRD study equationDuring the 16-week period eGFR increased insignificantlyin the male control group The male experimental groupexperienced a significant decrease of 71 (119875 lt 01) after week

6 BioMed Research International

Table3Ch

aracteris

ticso

fmalep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Maleg

reen

teag

roup

Malec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

33489plusmn69

30481plusmn79

Weight(kg)

33708plusmn136

716plusmn135

714plusmn138

30753plusmn133

759plusmn136

754plusmn134

BMI(kgm

2 )332467plusmn369

2497plusmn370(12)lowast

2487plusmn378(08)lowast

302628plusmn476

2646plusmn479(07)lowast

2623plusmn471(minus02)

Waist-

hipratio

33091plusmn006

090plusmn006(minus08)

089plusmn005(minus18

)lowast30

092plusmn005

091plusmn006(minus08)

090plusmn004(minus17

)lowastMAPa

(mmHg)

339349plusmn948

9285plusmn906(minus07)

9267plusmn1059(minus09)

299562plusmn870

9276plusmn873(minus30)lowast9229plusmn888(minus35)lowast

Glucose

(mgdL

)308970plusmn1118

9047plusmn1165(09)

9287plusmn945(35)

279056plusmn10358756plusmn1166(minus33)

8915plusmn1118(minus16

)HbA

1c(

)30

600[570ndash6

20]

590[570minus620]

605[580ndash6

30]lowast

28600[570ndash6

20]

590[560ndash6

10]lowast

595[570ndash6

10]

Cholesterol(mgdL

)3221875plusmn403919591plusmn3452(minus104)lowast19919plusmn3272(minus89)lowast

2921545plusmn400118486plusmn3534(minus142)lowast19410plusmn4206(minus99

)lowastTriglycerid

es(m

gdL

)3112542plusmn549712777plusmn5566(19)11555plusmn4838(minus79

)2612496plusmn477111558plusmn4115(minus75

)10804plusmn3881(minus135)lowast

LDL(m

gdL

)3214528plusmn337213147plusmn2853(minus95

)lowast13494plusmn2689(minus71)

2714789plusmn373412826plusmn2697(minus133)lowast13644plusmn3599(minus77

)HDL(m

gdL

)314858plusmn10924281plusmn1105(minus119)lowast4400plusmn1031(minus94

)lowast284554plusmn9413889plusmn830(minus146)lowast4086plusmn926(minus103)lowast

LDLHDL

31311plusmn085

322plusmn075(35)

322plusmn077(35)

26338plusmn103

329plusmn062(minus27)

341plusmn076(09)

Ferritin(ngdL

)2910045plusmn72689741plusmn6548(minus30)

9897plusmn6549(minus15

)268004plusmn471211142plusmn7586(392

)lowast10765plusmn7283(345)lowast

Album

in(gdL)

29450plusmn023

443plusmn020(minus14

)448plusmn020(minus05)

27450plusmn023

441plusmn023(minus21)lowast

447plusmn020(minus08)

Serum

creatin

ine(mgdL

)31

110[10

0ndash12

0]110[110ndash

120]

110[10

0ndash12

0]27

110[110ndash

120]

110[10

0ndash12

0]110[10

0ndash12

0]Urin

arycreatin

ine(mgdL

)2913152plusmn657618817plusmn9465(431)lowast17066plusmn7681(298

)lowast2913831plusmn701720038plusmn6494(449)lowast19738plusmn8027(427)lowast

Urea(

mgdL

)311442plusmn466

1465plusmn389(16)

1548plusmn394(74)

271363plusmn262

1385plusmn359(16)

1252plusmn264(minus82)lowast

eGFR

b(m

Lmin

per173m

2 )298262plusmn1673

7674plusmn900(minus71)lowast

7964plusmn1126(minus36)

278192plusmn1424

8424plusmn1379(28)

8555plusmn1535(44)

AST

c(IUL)

292635plusmn622

2641plusmn511(03)

2679plusmn554(17)

282711plusmn737

2693plusmn735(minus07)

2711plusmn721(00)

ALT

d(IUL)

322909plusmn16642706plusmn1345(minus70

)2781plusmn1139(minus44)

282825plusmn12992754plusmn1133(minus25)

2861plusmn1225(13)

TASe

(mmolL)

29160plusmn015

175plusmn011(95)lowast

192plusmn014(201)lowast

28162plusmn013

172plusmn010(62)lowast

192plusmn017(186)lowast

Hum

ansera

HT5

0(m

inutes)

281655plusmn257

1700plusmn272(27)lowast

1734plusmn265(48)lowast

281814plusmn313

1761plusmn255(minus29)

1780plusmn291(minus19

)Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereasno

nparam

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangesrelativetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

BioMed Research International 7

Table4Ch

aracteris

ticso

ffem

alep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Femaleg

reen

teag

roup

Femalec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

32493plusmn66

28469plusmn84

Weight(kg)

32613plusmn122

619plusmn124

617plusmn124

28632plusmn98

636plusmn98

637plusmn99

BMI(kgm

2 )31

2502plusmn366

2517plusmn359(06)

2507plusmn353(02)

282664plusmn329

2668plusmn334(01)

2674plusmn335(04)

Waist-

hipratio

31082plusmn005

082plusmn006(00)

084plusmn006(20)lowast

27083plusmn005

084plusmn005(18)lowast

085plusmn003(24)lowast

MAPa

(mmHg)

318880plusmn663

8774plusmn915(minus12

)8859plusmn916(minus02)

278894plusmn844

8663plusmn758(minus26)lowast

8685plusmn696(minus24)

Glucose

(mgdL

)329441plusmn1210

9484plusmn1347(05)9269plusmn1066(minus18

)28

9150plusmn970

9521plusmn1062(41)lowast

9121plusmn1169(minus03)

HbA

1c(

)30

610[590ndash6

50]

595

[580ndash

630]

610

[590ndash

640

]25

600

[578ndash610]

590

[580ndash

620]

600

[588ndash630]lowast

Cholesterol(mgdL

)3120987plusmn318119977plusmn3479(minus48)20813plusmn3711(minus08)

2820532plusmn475218879plusmn4214(minus81)lowast19404plusmn3234(minus55)lowast

Triglycerid

es(m

gdL

)3111855plusmn507311090plusmn5129(minus64)12490plusmn7412(54)

259368plusmn3353

10208plusmn3540(90)10316plusmn4548(101)

LDL(m

gdL

)3014040plusmn256812933plusmn2551(minus79

)lowast13830plusmn3003(minus15

)2713522plusmn385511663plusmn3705(minus137)lowast12882plusmn2620(minus47)

HDL(m

gdL

)315036plusmn10244842plusmn890(minus38)lowast4955plusmn920(minus16

)285207plusmn15294936plusmn1369(minus52)lowast4914plusmn1236(minus56)lowast

LDLHDL

29292plusmn083

276plusmn066(minus55)

290plusmn081(minus07)

27284plusmn125

251plusmn085(minus116)

275plusmn077(minus32)

Ferritin(ngdL

)294403plusmn36954917plusmn3675(117

)5055plusmn4501(14

8)

264273plusmn4205

4004plusmn3560(minus63)

4539plusmn4197(62)

Album

in(gdL)

29439plusmn026

435plusmn020(minus09)

445plusmn032(13)

25438plusmn016

428plusmn019(minus23)lowast

432plusmn019(minus14

)Serum

creatin

ine(mgdL

)31

090

[083ndash10

0]090

[080ndash

100]

080

[080ndash

098]lowast

28090

[080ndash

095]

090

[080ndash

090]

080

[080ndash

090]lowast

Urin

arycreatin

ine(mgdL

)309447plusmn534811163plusmn7663(182)8340plusmn6143(minus117)

239535plusmn3922

10461plusmn5790(97)8274plusmn5170(minus132)

Urea(

mgdL

)32

1147plusmn292

1163plusmn372(14)

1084plusmn284(minus54)

271063plusmn278

1007plusmn216(minus52)

989plusmn219(minus70

)eG

FRb(m

Lmin

per173m

2 )287770plusmn1600

8061plusmn1226(37)8259plusmn1175(63)lowast

278242plusmn1353

8516plusmn1364(33)

8993plusmn1365(91)lowast

AST

c(IUL)

312323plusmn492

2339plusmn472(07)

2236plusmn462(minus38)

272178plusmn536

2193plusmn498(07)

2256plusmn503(36)

ALT

d(IUL)

291800plusmn6721566plusmn369(minus130)lowast1621plusmn502(minus100)lowast

261739plusmn673

1619plusmn467(minus69)

1627plusmn534(minus64)

TASe

(mmolL)

29148plusmn011

166plusmn011(119

)lowast177plusmn009(19

6)lowast

24148plusmn011

160plusmn008(83)lowast

179plusmn015(211)lowast

Hum

ansera

HT5

0(m

inutes)

311600plusmn323

1682plusmn323(51)lowast

1657plusmn324(36)lowast

261601plusmn335

1586plusmn261(minus09)

1597plusmn307(minus02)

Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereas

nonp

aram

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangerela

tivetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

8 BioMed Research International

0100020003000400050006000700080009000

Mea

n ca

lorie

inde

xda

y (a

u)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

Figure 2 Daily mean calorie index variation for participants undergreen tea and water regimen during the 14-week interventionperiod and 2-week washout period in a male and female MauritianpopulationMain and error bars representmean values and standarddeviations respectively for experimental group (male 119899 = 33female 119899 = 32) and control group (male 119899 = 30 female 119899 = 28)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

0

100

200

300

400

500

600

Lipi

dfa

t rat

iod

ay (a

u)

Figure 3 Daily lipidfat ratio for participants under green teaand water regimen during the 14-week intervention period and 2-week washout period in a male and female Mauritian populationMain and error bars represent mean values and standard deviationsrespectively for experimental group (male 119899 = 33 female 119899 = 32)and control group (male 119899 = 30 female 119899 = 28)

14 followed by a critical increase of 38 (119875 lt 01) (relativeto week 14 value) after the washout period

The ALT a transaminase enzyme used to determineliver health decreased significantly by 130 (119875 lt 01) asillustrated by the female experimental group on week 14whereas female control group did not show any significantchange throughout the clinical trial The time taken forhuman sera to delay hemolysis by 50 representing theantioxidant potential of human sera at the cellular levelincreased significantly by 27 (119875 lt 01) and 51 (119875 lt 01) inmale and female experimental groups respectively afterweek14 whereas their corresponding control groups experienceda decrease

0

100

200

300

400

500

Control 025 050 100 150Tim

e tak

en fo

r 50

hem

olys

is to

occ

ur

HT5

0 (m

inut

es)

lowastlowastlowast

lowastlowastlowast

lowastlowastlowast

Green tea extracts (mgmL)

Figure 4 The prophylactic effect of green tea extracts against freeradical which might be a causative agent of metabolic syndromeMain and error bars represent mean value and standard deviationof three independent experiments respectively Statistical analyseswere performed using independent samples 119905-test for multiplecomparisons lowastlowastlowastTime taken for 50 hemolysis to occur wassignificantly different from that of control (119875 lt 001)

4 Discussion

The current management of type 2 diabetes involves acombination of dietary plans exercise programs and the useof drugs such as sulfonylureas and biguanide [34] Besidesthese conventional therapies a growing body of evidencehas indicated the role of green tea polyphenols in improvingfeatures of metabolic syndrome and subsequent risks fordiabetes and its complications [1 35] The putative beneficialeffects ascribed to green tea polyphenols are partly mediatedby their free radical scavenging antioxidant action and abil-ity to form complexes withmetal ionsThe green tea analysedin this study had high levels of total phenols flavonoids andproanthocyanidins with a wide range individual compoundsthat synergistically contributed to the antioxidative propen-sity of the extract as evidenced by the multiantioxidant anal-ysis data including the free radical-induced hemolysis assaydata (Figure 4) Similar observations were made in an earlierreport where green and black teas were characterised for theirantioxidant functions [36] The green tea supplementation inthis study led to a significant increase in serum antioxidantcapacity as measured by the free radical-induced hemolysisassay This suggests that the oxidative stress condition thatcan be encountered in diabetes [3 4] could benefit fromgreen tea consumption Raza and John [37] have reportedthat tea catechins can prevent protein degradation by alteringsubcellular reactive oxygen species production glutathionemetabolism and cytochrome P450 2E1 activity Grinberget al [38] found that tea polyphenols protect red blood cellsagainst primaquine-induced lysis and H

2O2-induced lipid

peroxidation While it can be further derived from the datain this study that green tea consumption can reinforce invivo antioxidant defences the potential prophylactic effectsof green tea against diabetes and its complications remain tobe clearly defined In the study the effect of cigarette smokingexcessive alcohol intake and hormone replacement therapyon levels of biomarkers measured were minimised by theexclusion criteria applied to the subject population Dietary

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

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MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

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Oxidative Medicine and Cellular Longevity

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PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

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Diabetes ResearchJournal of

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Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

2 BioMed Research International

120572-ketoaldehyde formation protein kinase C activation hex-osaminemetabolism sorbitolmetabolism dicarbonyl forma-tion and glycation These combined biochemical pathwaysplay a cardinal role in the pathogenesis of diabetes whosetherapeutic management is argued here to potentially benefitfrom adjunct inclusion of dietary biofactors in functionalbeverages [2 5]

The physiological effects of polyphenol-rich beverageshave continued to receive considerable attention as healthfuldietary sources of antioxidants [6 7] This growing body ofevidence advocates the role of green tea or its bioactive pol-yphenolic compounds in ameliorating features of metabolicsyndrome and subsequent risks for type 2 diabetes [8 9]Green tea contains important phytochemicals such as cat-echins gallic acid caffeic acid kaempferol myricetin andquercetin [10] These green tea polyphenols showed antiox-idant activities in vitro by scavenging reactive radical speciesand function indirectly as antioxidants through inhibition ofredox-sensitive transcription factors inhibition of ldquoprooxi-dantrdquo enzymes and induction of antioxidant enzymes [11 12]Several studies have shown that green tea controls glomerularfiltration rate lowers albuminuria attenuates hypertensionprevents free radical generation in cardiac myocytes andreduces renal advanced glycation end-product in diabeticnephropathy model rats [13ndash17] In this study the phytophe-nolic profiles of a green tea infusate were determined andits antioxidant potential was evaluated using a multiassayapproach The potential modulatory effects of green teaconsumption on some selected parameters including waist-hip ratio glucose level arterial pressure antioxidant statusalanine aminotransferase and lipid profiles were assessedover a defined period of time in individuals inclined todevelop type 2 diabetes

2 Materials and Methods

21 Reagents 221015840-Azobis(2-methylpropionamidine)dihydro-chloride (AAPH) was obtained from Sigma-Aldrich Inc (StLouis MO USA) Clinical biochemistry reagent kits werepurchased from Beckman Coulter Inc (Brea CA USA) andRandox Laboratories Ltd (Dublin UK)

22 Plant Material Camellia sinensis var sinensis (ChineseJat) was obtained as homogenous green tea bags (finishedproduct) from Bois Cheri Tea Estate (Bois Cheri Republicof Mauritius) The tea bag containing approximately 2 g ofgreen tea was manufactured on November 2010

23 Total Phenol Content Phenol was determined by themethod of Singleton and Rossi [18]

24 Total Flavonoid Content Flavonoid was determined bythe method of Lamaison and Carnet [19]

25 Total Proanthocyanidin Content Proanthocyanidin wasdetermined by the method of Porter et al [20]

26 High-Performance Liquid Chromatography

261 Sample Preparation One green tea bag was infused in100mL hot water (100∘C) for 6minutes as described byWanget al [21] The brew was cooled under running tap water andcentrifuged at 4000 rpm for 15 minutes at 25∘C For gallicacid (+)-catechin (minus)-epigallocatechin (minus)-epigallocatechingallate (minus)-epicatechin gallate procyanidin B2 and (minus)-epicatechin analyses the supernatant was mixed with abso-lute methanol in a 2 1 supernatant methanol vv ratio priorto HPLC analysis

Myricetin kaempferol and quercetin were identified andquantified in green tea infusate after acid hydrolysis offlavonol conjugates essentially as follows and using morinas internal standard the supernatant was mixed with 6MHCL in a 8 1 supernatant 6MHCL vv ratio and incubatedat 85∘C for 25 hours After cooling the hydrolysed greentea supernatant extract was taken up in absolute methanol(3 1 vv hydrolysed green tea extract absolute methanol)prior to HPLC analysis

262 Chromatographic Conditions HPLC analysis of thegreen tea infusate was carried out using a Hewlett Packard1100 series (Waldbronn Germany) liquid chromatographysystem equipped with a vacuum degasser quaternary pumpautosampler thermostated column compartment and diodearray detector After filtration (022120583m filter paper) (Mil-lipore Corporation Bedford USA) 60120583L of extract wasinjected into a Zorbax SB-C18 column (46mm internaldiameter times 250mm length 35 120583m pore size) (Agilent Tech-nologies CA USA) Elution with a flow rate of 07mLminat 35∘C was as follows 0ndash30min 0ndash10 B in A 30ndash50min10ndash15 B in A 50ndash60min 15ndash25 B in A 60ndash90min 25ndash100 B in A 90ndash100min 100ndash0 B in A (Solvent A ace-tonitrilewater 19 vv pH 25 Solvent B acetonitrilewater11 vv pH 25 adjusted with phosphoric acid) The diodearray detector was set at 280 nm for the quantitative determi-nation of gallic acid and flavan-3-ol derivatives and at 365 nmfor flavonol aglycones The identification and quantificationof these phenolics were determined from retention timesand peak areas in comparison with authentic standardsResults were expressed in appropriate standards (mg) percup (200mL) Green tea extracts were analysed in triplicateCalibrated graphs of authentic standards were preparedvia appropriate serial dilutions with methanol and filtered(022 120583m) before use Calibration graphs were obtained byplotting the peak area of authentic standards versus theirknown quantities (05ndash45120583g)

27 Sample Preparation for Antioxidant and Free Radical-Induced Hemolysis Assays Two grams of green tea (equiva-lent to 1 tea bag) were infused in 200mL hot water (100∘C)for 6 minutes The green tea brew was cooled under runningtap water and filtered through a 02 120583m nylon filter The brewwas diluted to generate different concentrations of green teaextracts (01mgmL to 10mgmL) for use in antioxidant andfree radical-induced hemolysis assays

BioMed Research International 3

271 Antioxidant Assays

(1) Superoxide Radical Scavenging Assay The superoxideanion radical scavenging activity of green tea was measuredaccording to Nishikimi et al [22] with slight modifications

(2) Nitric Oxide Radical Scavenging Assay The nitric oxideradical scavenging activity of green tea wasmeasured accord-ing to Garratt [23] with slight modifications

(3) 221015840-Azino-bis (3-Ethylbenzothiazoline-6-sulfonic Acid)Radical Scavenging AssayThe ABTS∙+ scavenging activity ofgreen tea was measured according to Henriquez et al [24]with slight modifications

(4) Ferric ReducingAntioxidant PowerAssayThe ferric reduc-ing activity of green tea was measured according to Benzieand Strain [25] with slight modifications

(5) 22-Diphenyl-1-picrylhydrazyl Radical Scavenging AssayThe DPPH scavenging activity of green tea was measuredaccording to Sharma and Bhat [26] with slight modifications

(6) Ferrous Ion Chelating Assay The ferrous ion chelatingactivity of green tea was assessed according to Stookey [27]with slight modifications

(7) Hypochlorous Acid Scavenging Assay The hypochlorousacid scavenging activity of green tea was assessed accordingto Wang et al [28] and Aruoma and Halliwell [29]

272 Free Radical-Induced Hemolysis Assay The antioxidantactivities of green tea extracts and human sera derived fromthe clinical trial were evaluated using an assay based on freeradical-induced hemolysis [30]

28 Clinical Trial

281 Subjects Three hundred prediabetic Mauritians whoparticipated in a 2009 nationwide survey that was organizedby the Non-Communicable Diseases Unit of the Ministryof Health and Quality of Life Republic of Mauritius wereselected for the randomized controlled clinical trial (Clinical-Trialsgov IdentifiermdashNCT01248143) The inclusion criteriawere individuals at risk of diabetes (fasting plasma glucoseranged from 110 to 126mgdLmeasured using the hexokinasemethod) age ranged from 35 to 65 years The exclusioncriteria were smokers or those who have stopped smoking 6months before the clinical trial daily alcoholic intake exceed-ing two standard drinks postmenopausal women receiv-ing hormone replacement therapy hypertensive patients(gt14090mmHg) The clinical trial was approved by theNational Ethics Committee of the Ministry of Health andQuality of Life Republic of Mauritius and endorsed bythe Institutional Review Board at Touro College of HealthSciences (Bay Shore NY USA) The study was conducted inaccordance with the guidelines of the Declaration of Helsinkiprinciples All subjects gave written informed consent beforeclinical trial enrolment

282 Trial Profile and Study Design The clinical trial wasconducted from November 2010 to March 2011 at the Car-diac Centre of the Sir Seewoosagur Ramgoolam NationalHospital Pamplemousses Republic of Mauritius over a 16-week period The experimental group (119899 = 65) consumedone cup of green tea infusate (1 green tea bag infused for6min in 200mL hot water without milk or sugar) threetimes a day before meals (breakfast lunch and dinner) for14 weeks followed by a 2-week washout period The controlgroup (119899 = 58) consumed an equivalent volume of warmwater during the 16-week period (Figure 1) The randomallocation sequence was generated by a qualified statisticianusing a random generator that takes into account an unbiasedage and gender distribution within each group A simplerandomization approach with blocking for gender was usedto allocate subjects into their respective groups Participantswere instructed to maintain their usual daily activities andtheir former diet during the clinical trial

283 Dietary Survey Questionnaires Participants were con-tacted twice a week via phone to remind them to keepa record of all food and beverages consumed during theclinical trial A questionnaire indicating food and beverageitems consumed daily during the three main meals wasissued to each participant and was collected duly filled afterblood sampling exerciseDietary information provided by theparticipants enabled the assessment of any possible changesin the diet during the clinical trial Descriptive statistics ofthese questionnaires were based on daily mean calorie indexand daily lipidfat ratio [31] observed during the 14-weekintervention period and the 2-week washout period

284 Anthropometry and Blood Pressure Anthropometricand blood pressure data were recorded for each participantHeight was measured to the nearest 05 cm without shoesusing a calibrated stadiometerWeight wasmeasured withoutshoes and excess clothing to the nearest 01 kg using acalibrated mechanical beam balance BMI was calculated asweight in kilograms divided by height in squaremetersWaistand hip circumference was measured to the nearest 05 cmusing a dressmakerrsquos measuring tape applied horizontallyWaist girth was measured at the midpoint between the iliaccrest and the lowermargin of the ribs Hip girth was recordedas the maximum circumference around the buttocks Waist-hip ratio was calculated as waist in cm divided by hip incm Blood pressure was measured on the right upper armin seated and supine position after resting for five minuteswith an automatic device (Automatic blood pressure monitorModel SEM-1 OmronHealthcare Company Singapore) Twomeasurements were taken with 1 minute interval betweenthem and the mean of the 2 measurements was calculatedThese blood pressure values were used to calculate meanarterial pressure using the standard formula 23 diastolicblood pressure + 13 systolic blood pressure

285 Sample Collection 20mL of bloodwas collected underthe guidance of physicians from each participant fastingfor at least 12 hours The blood was dispensed appropriately

4 BioMed Research International

145 declined to participate

155 randomly allocated to

Experimental group(male n = 40 female n = 37)

Control group(male n = 43 female n = 35)

Completed 16-week period(male n = 33 female n = 32) (male n = 30 female n = 28)

300 participants met inclusion criteria and were invited to participate in the clinical study

Green tea regimen1 cup of green tea 3 times a day before

meals for 14 weeks

Water regimen1 cup of warm water 3 times a day before

meals for 14 weeks

Washout period1 cup of warm water 3 times a day before

meals for 2 weeks1 cup of warm water 3 times a day before

meals for 2 weeks

intervention12 lost to followup or discontinued 12 lost to followup or discontinued

intervention

Washout period

Completed 16-week period

Figure 1 Flow diagram showing trial profile and study design

into EDTA-K3 tube sodium fluoride oxalate tube and plaintubes Biological samples were kept at 4∘C and transportedfor analysis to Apollo Bramwell Hospital Moka Republicof Mauritius Before conducting any assays all tubes werecentrifuged at 3000 rpm for 7min at 25∘C with the exceptionof EDTA-K3 tube Human sera from plain tubes were usedfor free radical-induced hemolysis and clinical biochemistryassay Whole blood from EDTA-K3 tubes and human plasmafrom sodiumfluoride oxalate tubeswere used only for clinicalbiochemistry assay

286 Clinical Biochemistry Assay Human sera obtainedfrom plain tubes were tested for total cholesterol LDL HDLtriglycerides urea albumin creatinine ferritin total antiox-idant status aminotransferase aspartate (AST) and ALTHuman plasma obtained from sodium fluoride oxalate tubeswere tested for glucose Whole blood from EDTA-K3 tubewas used to determine glycated haemoglobin Using stan-dardized methods the automated Beckman Coulter AU480analyzer was used to quantify all biomarkers except totalantioxidant status which was evaluated by RX Daytona ana-lyzer All clinical biochemistry assays were completed within24 h after sample collection Serum creatinine (nonisotopedilution mass spectrometry traceable) urea and albuminwere used to estimate glomerular filtration rate (eGFR) usingthe ldquomodification of diet in renal diseaserdquo (MDRD) formula[32]

29 Statistical Analysis Parametric and nonparametric vari-ables are expressed after omitting outliers as mean plusmn stan-dard deviation and median [interquartile range] respec-tively Simple regression analysis was performed to calculate

the dose-dependent relationship of green tea extracts indifferent antioxidant assays Data derived from antioxidantassays were fitted into appropriate regressionmodel [33] (lin-ear polynomial order 2 or polynomial order 3) that allowedus to determine AA

50 Statistical inference was carried out

after omitting outliers using MedCalc for Windows (version11600 Mariakerke Belgium) Significant differences overtime within each group were determined using pairedStudentrsquos 119905-test and where data was not normal the non-parametric alternative Wilcoxon test was used Significantdifferences over time between each group were determinedusing independent samples 119905-test and where data was notnormal the nonparametric alternative Mann-Whitney testwas used The level for establishing significant differenceswas set at 10 successively Statistical analyses were alsoperformed to calculate any significant correlations betweenindividual variables daily mean calorie index and dailylipidfat ratio Pearson or Spearman rank correlation coeffi-cient was used for normally or nonnormally distributed datasets respectively Correlation analyses between individualvariables daily mean calorie index and daily lipidfat ratiowere carried out separately on week 14 and washout data setswhereby gender stratified data were taken into account Allstatistical tests were two-tailed

3 Results

31 Phytophenolic Composition of Mauritian Green Tea TheMauritian green tea phytophenolic profile is shown inTable 1 The most prominent phytophenolics in an unhy-drolyzed Mauritian green tea infusate were ranked accord-ing to their quantity per cup (200mL) in the followingdecreasing order procyanidin B2 gt (minus)-epigallocatechin

BioMed Research International 5

Table 1 Mauritian green tea phytophenolic data

Phytophenolic of unhydrolyzed Mauritian green teamg per cup(200mL)

Total phenol 23513 plusmn 3089a

Total flavonoid 752 plusmn 097b

Total proanthocyanidin 789 plusmn 063b

Procyanidin B2 49692 plusmn 2008c

(minus)-Epigallocatechin gallate 23468 plusmn 1208d

(minus)-Epigallocatechin 20512 plusmn 2542e

(minus)-Epicatechin gallate 2846 plusmn 180f

(minus)-Epicatechin 2442 plusmn 208g

(+)-Catechin 1390 plusmn 220h

Gallic acid 166 plusmn 016i

Phytophenolics in hydrolyzed Mauritian green teamg per cup(200mL)

Quercetin 150 plusmn 016j

Myricetin 148 plusmn 014j

Kaempferol 090 plusmn 008k

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant dif-ferences between mean phytophenolic contents (119875 lt 005) Free flavonoidswere not detected in the green tea extract however after hydrolysis HPLCanalysis showed that quercetin kaempferol and myricetin were the mainflavonol aglycones present in the following decreasing order quercetin gtmyricetin gt kaempferol

gallate gt (minus)-epigallocatechin gt (minus)-epicatechin gallategt (minus)-epicatechin gt (+)-catechin gt gallic acid Procyanidin B2 wasfound to be the most important compound with 49692mgper cup (200mL) while gallic acid was least prominent(166mg per cup)

32 Antioxidant Capacities of Mauritian Green Tea Thegreen tea antioxidant profile was characterized using 7 inde-pendent assays (Table 2) at concentrations varying from01 to 1mgmL A concentration ranking order indicat-ing 50 antioxidant activity (AA

50) for the green tea ex-

tract in each antioxidant assay was established as followsABTS∙+ scavenging activity (001mgmL) gt ferric reduc-ing activity (004mgmL) gt nitric oxide scavenging activ-ity (030mgmL) gt Fe2+ chelating activity (033mgmL) gtHOCL scavenging activity (039mgmL) gt superoxide scav-enging activity (042mgmL) gt DPPH scavenging activity(052mgmL) The data showed that the Mauritian greentea extract had a higher predisposition (119875 lt 005) to theABTS∙+ radical than the DPPH radical It also revealed anonsignificant (119875 gt 005) sensitivity to hypochlorous acidand superoxide anion radical Moreover Mauritian green teahad a higher affinity (119875 lt 005) to reduce Fe3+ into Fe2+ thanto chelate Fe2+

33 Clinical Trial A randomized controlled clinical trialwas conducted on humans predisposed to type 2 diabetesAmong the 300 participants that met the inclusion criteria

Table 2 Antioxidant activities of Mauritian green tea using a mul-tiassay approach

Antioxidant assays AA50 (mgmL)ABTS radical scavenging assay 001 plusmn 0001a

FRAP assay 004 plusmn 001b

Nitric oxide radical scavenging assay 030 plusmn 001c

Ferrous ions chelating assay 033 plusmn 003cd

HOCL scavenging assay 039 plusmn 003de

Superoxide radical scavenging assay 042 plusmn 001e

DPPH radical scavenging assay 052 plusmn 001f

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant differ-ences between mean AA50 (119875 lt 005) AA50 was defined as Mauritian greentea concentration that revealed a 50 antioxidant activity

155 agreed to enrol in the clinical trial and theywere randomlyallocated into the experimental and control groupThe num-ber of participants at the end of the clinical trial was 123representing a 206 dropout from initial population sizeThe final experimental and control groups consisted of 65and 58 participants respectively No subject withdrew fromthe clinical trial due to discomfort or any adverse effectsassociated with the regimen The complied dietary surveyquestionnaires showed that the daily mean calorie index anddaily lipidfat ratio remained relatively constant for both theexperimental and control groups in the male and femalepopulation during the 14-week intervention period and the2-week washout period (Figures 2 and 3) No correlationanalyses between individual variables daily mean calorieindex and daily lipidfat ratio for any group or gender turnedout to be significant nor were there any consistency in thedirection of correlations

The data in Tables 3 and 4 define the anthropometricand biochemical characteristics measured at the beginningof the study at the end of the 14-week intervention periodand after the 2-weekwashout period During the clinical trialwaist-hip ratio an indicator of obesity increased significantly(119875 lt 01) in the female control group whereas the femaleexperimental group did not experience any change on week14Mean arterial pressure defined as the average arterial pres-sure during a single cardiac cycle decreased insignificantly onweek 14 as indicated by the experimental group whereas maleand female control groups endured a critical decline of 30(119875 lt 01) and 26 (119875 lt 01) respectively

Based on the findings set out in Table 3 male subjectsunder green tea regimen showed an insignificant reduction of30 in ferritin concentration after week 14 whereas in malecontrol group its concentration rose considerably by 392(119875 lt 01) Moreover the green tea regimen did not affect thefasting plasma glucose of subjects

eGFR used to diagnose and monitor kidney functionwas estimated using the 6-variable MDRD study equationDuring the 16-week period eGFR increased insignificantlyin the male control group The male experimental groupexperienced a significant decrease of 71 (119875 lt 01) after week

6 BioMed Research International

Table3Ch

aracteris

ticso

fmalep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Maleg

reen

teag

roup

Malec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

33489plusmn69

30481plusmn79

Weight(kg)

33708plusmn136

716plusmn135

714plusmn138

30753plusmn133

759plusmn136

754plusmn134

BMI(kgm

2 )332467plusmn369

2497plusmn370(12)lowast

2487plusmn378(08)lowast

302628plusmn476

2646plusmn479(07)lowast

2623plusmn471(minus02)

Waist-

hipratio

33091plusmn006

090plusmn006(minus08)

089plusmn005(minus18

)lowast30

092plusmn005

091plusmn006(minus08)

090plusmn004(minus17

)lowastMAPa

(mmHg)

339349plusmn948

9285plusmn906(minus07)

9267plusmn1059(minus09)

299562plusmn870

9276plusmn873(minus30)lowast9229plusmn888(minus35)lowast

Glucose

(mgdL

)308970plusmn1118

9047plusmn1165(09)

9287plusmn945(35)

279056plusmn10358756plusmn1166(minus33)

8915plusmn1118(minus16

)HbA

1c(

)30

600[570ndash6

20]

590[570minus620]

605[580ndash6

30]lowast

28600[570ndash6

20]

590[560ndash6

10]lowast

595[570ndash6

10]

Cholesterol(mgdL

)3221875plusmn403919591plusmn3452(minus104)lowast19919plusmn3272(minus89)lowast

2921545plusmn400118486plusmn3534(minus142)lowast19410plusmn4206(minus99

)lowastTriglycerid

es(m

gdL

)3112542plusmn549712777plusmn5566(19)11555plusmn4838(minus79

)2612496plusmn477111558plusmn4115(minus75

)10804plusmn3881(minus135)lowast

LDL(m

gdL

)3214528plusmn337213147plusmn2853(minus95

)lowast13494plusmn2689(minus71)

2714789plusmn373412826plusmn2697(minus133)lowast13644plusmn3599(minus77

)HDL(m

gdL

)314858plusmn10924281plusmn1105(minus119)lowast4400plusmn1031(minus94

)lowast284554plusmn9413889plusmn830(minus146)lowast4086plusmn926(minus103)lowast

LDLHDL

31311plusmn085

322plusmn075(35)

322plusmn077(35)

26338plusmn103

329plusmn062(minus27)

341plusmn076(09)

Ferritin(ngdL

)2910045plusmn72689741plusmn6548(minus30)

9897plusmn6549(minus15

)268004plusmn471211142plusmn7586(392

)lowast10765plusmn7283(345)lowast

Album

in(gdL)

29450plusmn023

443plusmn020(minus14

)448plusmn020(minus05)

27450plusmn023

441plusmn023(minus21)lowast

447plusmn020(minus08)

Serum

creatin

ine(mgdL

)31

110[10

0ndash12

0]110[110ndash

120]

110[10

0ndash12

0]27

110[110ndash

120]

110[10

0ndash12

0]110[10

0ndash12

0]Urin

arycreatin

ine(mgdL

)2913152plusmn657618817plusmn9465(431)lowast17066plusmn7681(298

)lowast2913831plusmn701720038plusmn6494(449)lowast19738plusmn8027(427)lowast

Urea(

mgdL

)311442plusmn466

1465plusmn389(16)

1548plusmn394(74)

271363plusmn262

1385plusmn359(16)

1252plusmn264(minus82)lowast

eGFR

b(m

Lmin

per173m

2 )298262plusmn1673

7674plusmn900(minus71)lowast

7964plusmn1126(minus36)

278192plusmn1424

8424plusmn1379(28)

8555plusmn1535(44)

AST

c(IUL)

292635plusmn622

2641plusmn511(03)

2679plusmn554(17)

282711plusmn737

2693plusmn735(minus07)

2711plusmn721(00)

ALT

d(IUL)

322909plusmn16642706plusmn1345(minus70

)2781plusmn1139(minus44)

282825plusmn12992754plusmn1133(minus25)

2861plusmn1225(13)

TASe

(mmolL)

29160plusmn015

175plusmn011(95)lowast

192plusmn014(201)lowast

28162plusmn013

172plusmn010(62)lowast

192plusmn017(186)lowast

Hum

ansera

HT5

0(m

inutes)

281655plusmn257

1700plusmn272(27)lowast

1734plusmn265(48)lowast

281814plusmn313

1761plusmn255(minus29)

1780plusmn291(minus19

)Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereasno

nparam

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangesrelativetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

BioMed Research International 7

Table4Ch

aracteris

ticso

ffem

alep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Femaleg

reen

teag

roup

Femalec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

32493plusmn66

28469plusmn84

Weight(kg)

32613plusmn122

619plusmn124

617plusmn124

28632plusmn98

636plusmn98

637plusmn99

BMI(kgm

2 )31

2502plusmn366

2517plusmn359(06)

2507plusmn353(02)

282664plusmn329

2668plusmn334(01)

2674plusmn335(04)

Waist-

hipratio

31082plusmn005

082plusmn006(00)

084plusmn006(20)lowast

27083plusmn005

084plusmn005(18)lowast

085plusmn003(24)lowast

MAPa

(mmHg)

318880plusmn663

8774plusmn915(minus12

)8859plusmn916(minus02)

278894plusmn844

8663plusmn758(minus26)lowast

8685plusmn696(minus24)

Glucose

(mgdL

)329441plusmn1210

9484plusmn1347(05)9269plusmn1066(minus18

)28

9150plusmn970

9521plusmn1062(41)lowast

9121plusmn1169(minus03)

HbA

1c(

)30

610[590ndash6

50]

595

[580ndash

630]

610

[590ndash

640

]25

600

[578ndash610]

590

[580ndash

620]

600

[588ndash630]lowast

Cholesterol(mgdL

)3120987plusmn318119977plusmn3479(minus48)20813plusmn3711(minus08)

2820532plusmn475218879plusmn4214(minus81)lowast19404plusmn3234(minus55)lowast

Triglycerid

es(m

gdL

)3111855plusmn507311090plusmn5129(minus64)12490plusmn7412(54)

259368plusmn3353

10208plusmn3540(90)10316plusmn4548(101)

LDL(m

gdL

)3014040plusmn256812933plusmn2551(minus79

)lowast13830plusmn3003(minus15

)2713522plusmn385511663plusmn3705(minus137)lowast12882plusmn2620(minus47)

HDL(m

gdL

)315036plusmn10244842plusmn890(minus38)lowast4955plusmn920(minus16

)285207plusmn15294936plusmn1369(minus52)lowast4914plusmn1236(minus56)lowast

LDLHDL

29292plusmn083

276plusmn066(minus55)

290plusmn081(minus07)

27284plusmn125

251plusmn085(minus116)

275plusmn077(minus32)

Ferritin(ngdL

)294403plusmn36954917plusmn3675(117

)5055plusmn4501(14

8)

264273plusmn4205

4004plusmn3560(minus63)

4539plusmn4197(62)

Album

in(gdL)

29439plusmn026

435plusmn020(minus09)

445plusmn032(13)

25438plusmn016

428plusmn019(minus23)lowast

432plusmn019(minus14

)Serum

creatin

ine(mgdL

)31

090

[083ndash10

0]090

[080ndash

100]

080

[080ndash

098]lowast

28090

[080ndash

095]

090

[080ndash

090]

080

[080ndash

090]lowast

Urin

arycreatin

ine(mgdL

)309447plusmn534811163plusmn7663(182)8340plusmn6143(minus117)

239535plusmn3922

10461plusmn5790(97)8274plusmn5170(minus132)

Urea(

mgdL

)32

1147plusmn292

1163plusmn372(14)

1084plusmn284(minus54)

271063plusmn278

1007plusmn216(minus52)

989plusmn219(minus70

)eG

FRb(m

Lmin

per173m

2 )287770plusmn1600

8061plusmn1226(37)8259plusmn1175(63)lowast

278242plusmn1353

8516plusmn1364(33)

8993plusmn1365(91)lowast

AST

c(IUL)

312323plusmn492

2339plusmn472(07)

2236plusmn462(minus38)

272178plusmn536

2193plusmn498(07)

2256plusmn503(36)

ALT

d(IUL)

291800plusmn6721566plusmn369(minus130)lowast1621plusmn502(minus100)lowast

261739plusmn673

1619plusmn467(minus69)

1627plusmn534(minus64)

TASe

(mmolL)

29148plusmn011

166plusmn011(119

)lowast177plusmn009(19

6)lowast

24148plusmn011

160plusmn008(83)lowast

179plusmn015(211)lowast

Hum

ansera

HT5

0(m

inutes)

311600plusmn323

1682plusmn323(51)lowast

1657plusmn324(36)lowast

261601plusmn335

1586plusmn261(minus09)

1597plusmn307(minus02)

Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereas

nonp

aram

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangerela

tivetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

8 BioMed Research International

0100020003000400050006000700080009000

Mea

n ca

lorie

inde

xda

y (a

u)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

Figure 2 Daily mean calorie index variation for participants undergreen tea and water regimen during the 14-week interventionperiod and 2-week washout period in a male and female MauritianpopulationMain and error bars representmean values and standarddeviations respectively for experimental group (male 119899 = 33female 119899 = 32) and control group (male 119899 = 30 female 119899 = 28)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

0

100

200

300

400

500

600

Lipi

dfa

t rat

iod

ay (a

u)

Figure 3 Daily lipidfat ratio for participants under green teaand water regimen during the 14-week intervention period and 2-week washout period in a male and female Mauritian populationMain and error bars represent mean values and standard deviationsrespectively for experimental group (male 119899 = 33 female 119899 = 32)and control group (male 119899 = 30 female 119899 = 28)

14 followed by a critical increase of 38 (119875 lt 01) (relativeto week 14 value) after the washout period

The ALT a transaminase enzyme used to determineliver health decreased significantly by 130 (119875 lt 01) asillustrated by the female experimental group on week 14whereas female control group did not show any significantchange throughout the clinical trial The time taken forhuman sera to delay hemolysis by 50 representing theantioxidant potential of human sera at the cellular levelincreased significantly by 27 (119875 lt 01) and 51 (119875 lt 01) inmale and female experimental groups respectively afterweek14 whereas their corresponding control groups experienceda decrease

0

100

200

300

400

500

Control 025 050 100 150Tim

e tak

en fo

r 50

hem

olys

is to

occ

ur

HT5

0 (m

inut

es)

lowastlowastlowast

lowastlowastlowast

lowastlowastlowast

Green tea extracts (mgmL)

Figure 4 The prophylactic effect of green tea extracts against freeradical which might be a causative agent of metabolic syndromeMain and error bars represent mean value and standard deviationof three independent experiments respectively Statistical analyseswere performed using independent samples 119905-test for multiplecomparisons lowastlowastlowastTime taken for 50 hemolysis to occur wassignificantly different from that of control (119875 lt 001)

4 Discussion

The current management of type 2 diabetes involves acombination of dietary plans exercise programs and the useof drugs such as sulfonylureas and biguanide [34] Besidesthese conventional therapies a growing body of evidencehas indicated the role of green tea polyphenols in improvingfeatures of metabolic syndrome and subsequent risks fordiabetes and its complications [1 35] The putative beneficialeffects ascribed to green tea polyphenols are partly mediatedby their free radical scavenging antioxidant action and abil-ity to form complexes withmetal ionsThe green tea analysedin this study had high levels of total phenols flavonoids andproanthocyanidins with a wide range individual compoundsthat synergistically contributed to the antioxidative propen-sity of the extract as evidenced by the multiantioxidant anal-ysis data including the free radical-induced hemolysis assaydata (Figure 4) Similar observations were made in an earlierreport where green and black teas were characterised for theirantioxidant functions [36] The green tea supplementation inthis study led to a significant increase in serum antioxidantcapacity as measured by the free radical-induced hemolysisassay This suggests that the oxidative stress condition thatcan be encountered in diabetes [3 4] could benefit fromgreen tea consumption Raza and John [37] have reportedthat tea catechins can prevent protein degradation by alteringsubcellular reactive oxygen species production glutathionemetabolism and cytochrome P450 2E1 activity Grinberget al [38] found that tea polyphenols protect red blood cellsagainst primaquine-induced lysis and H

2O2-induced lipid

peroxidation While it can be further derived from the datain this study that green tea consumption can reinforce invivo antioxidant defences the potential prophylactic effectsof green tea against diabetes and its complications remain tobe clearly defined In the study the effect of cigarette smokingexcessive alcohol intake and hormone replacement therapyon levels of biomarkers measured were minimised by theexclusion criteria applied to the subject population Dietary

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

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Diabetes ResearchJournal of

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Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

BioMed Research International 3

271 Antioxidant Assays

(1) Superoxide Radical Scavenging Assay The superoxideanion radical scavenging activity of green tea was measuredaccording to Nishikimi et al [22] with slight modifications

(2) Nitric Oxide Radical Scavenging Assay The nitric oxideradical scavenging activity of green tea wasmeasured accord-ing to Garratt [23] with slight modifications

(3) 221015840-Azino-bis (3-Ethylbenzothiazoline-6-sulfonic Acid)Radical Scavenging AssayThe ABTS∙+ scavenging activity ofgreen tea was measured according to Henriquez et al [24]with slight modifications

(4) Ferric ReducingAntioxidant PowerAssayThe ferric reduc-ing activity of green tea was measured according to Benzieand Strain [25] with slight modifications

(5) 22-Diphenyl-1-picrylhydrazyl Radical Scavenging AssayThe DPPH scavenging activity of green tea was measuredaccording to Sharma and Bhat [26] with slight modifications

(6) Ferrous Ion Chelating Assay The ferrous ion chelatingactivity of green tea was assessed according to Stookey [27]with slight modifications

(7) Hypochlorous Acid Scavenging Assay The hypochlorousacid scavenging activity of green tea was assessed accordingto Wang et al [28] and Aruoma and Halliwell [29]

272 Free Radical-Induced Hemolysis Assay The antioxidantactivities of green tea extracts and human sera derived fromthe clinical trial were evaluated using an assay based on freeradical-induced hemolysis [30]

28 Clinical Trial

281 Subjects Three hundred prediabetic Mauritians whoparticipated in a 2009 nationwide survey that was organizedby the Non-Communicable Diseases Unit of the Ministryof Health and Quality of Life Republic of Mauritius wereselected for the randomized controlled clinical trial (Clinical-Trialsgov IdentifiermdashNCT01248143) The inclusion criteriawere individuals at risk of diabetes (fasting plasma glucoseranged from 110 to 126mgdLmeasured using the hexokinasemethod) age ranged from 35 to 65 years The exclusioncriteria were smokers or those who have stopped smoking 6months before the clinical trial daily alcoholic intake exceed-ing two standard drinks postmenopausal women receiv-ing hormone replacement therapy hypertensive patients(gt14090mmHg) The clinical trial was approved by theNational Ethics Committee of the Ministry of Health andQuality of Life Republic of Mauritius and endorsed bythe Institutional Review Board at Touro College of HealthSciences (Bay Shore NY USA) The study was conducted inaccordance with the guidelines of the Declaration of Helsinkiprinciples All subjects gave written informed consent beforeclinical trial enrolment

282 Trial Profile and Study Design The clinical trial wasconducted from November 2010 to March 2011 at the Car-diac Centre of the Sir Seewoosagur Ramgoolam NationalHospital Pamplemousses Republic of Mauritius over a 16-week period The experimental group (119899 = 65) consumedone cup of green tea infusate (1 green tea bag infused for6min in 200mL hot water without milk or sugar) threetimes a day before meals (breakfast lunch and dinner) for14 weeks followed by a 2-week washout period The controlgroup (119899 = 58) consumed an equivalent volume of warmwater during the 16-week period (Figure 1) The randomallocation sequence was generated by a qualified statisticianusing a random generator that takes into account an unbiasedage and gender distribution within each group A simplerandomization approach with blocking for gender was usedto allocate subjects into their respective groups Participantswere instructed to maintain their usual daily activities andtheir former diet during the clinical trial

283 Dietary Survey Questionnaires Participants were con-tacted twice a week via phone to remind them to keepa record of all food and beverages consumed during theclinical trial A questionnaire indicating food and beverageitems consumed daily during the three main meals wasissued to each participant and was collected duly filled afterblood sampling exerciseDietary information provided by theparticipants enabled the assessment of any possible changesin the diet during the clinical trial Descriptive statistics ofthese questionnaires were based on daily mean calorie indexand daily lipidfat ratio [31] observed during the 14-weekintervention period and the 2-week washout period

284 Anthropometry and Blood Pressure Anthropometricand blood pressure data were recorded for each participantHeight was measured to the nearest 05 cm without shoesusing a calibrated stadiometerWeight wasmeasured withoutshoes and excess clothing to the nearest 01 kg using acalibrated mechanical beam balance BMI was calculated asweight in kilograms divided by height in squaremetersWaistand hip circumference was measured to the nearest 05 cmusing a dressmakerrsquos measuring tape applied horizontallyWaist girth was measured at the midpoint between the iliaccrest and the lowermargin of the ribs Hip girth was recordedas the maximum circumference around the buttocks Waist-hip ratio was calculated as waist in cm divided by hip incm Blood pressure was measured on the right upper armin seated and supine position after resting for five minuteswith an automatic device (Automatic blood pressure monitorModel SEM-1 OmronHealthcare Company Singapore) Twomeasurements were taken with 1 minute interval betweenthem and the mean of the 2 measurements was calculatedThese blood pressure values were used to calculate meanarterial pressure using the standard formula 23 diastolicblood pressure + 13 systolic blood pressure

285 Sample Collection 20mL of bloodwas collected underthe guidance of physicians from each participant fastingfor at least 12 hours The blood was dispensed appropriately

4 BioMed Research International

145 declined to participate

155 randomly allocated to

Experimental group(male n = 40 female n = 37)

Control group(male n = 43 female n = 35)

Completed 16-week period(male n = 33 female n = 32) (male n = 30 female n = 28)

300 participants met inclusion criteria and were invited to participate in the clinical study

Green tea regimen1 cup of green tea 3 times a day before

meals for 14 weeks

Water regimen1 cup of warm water 3 times a day before

meals for 14 weeks

Washout period1 cup of warm water 3 times a day before

meals for 2 weeks1 cup of warm water 3 times a day before

meals for 2 weeks

intervention12 lost to followup or discontinued 12 lost to followup or discontinued

intervention

Washout period

Completed 16-week period

Figure 1 Flow diagram showing trial profile and study design

into EDTA-K3 tube sodium fluoride oxalate tube and plaintubes Biological samples were kept at 4∘C and transportedfor analysis to Apollo Bramwell Hospital Moka Republicof Mauritius Before conducting any assays all tubes werecentrifuged at 3000 rpm for 7min at 25∘C with the exceptionof EDTA-K3 tube Human sera from plain tubes were usedfor free radical-induced hemolysis and clinical biochemistryassay Whole blood from EDTA-K3 tubes and human plasmafrom sodiumfluoride oxalate tubeswere used only for clinicalbiochemistry assay

286 Clinical Biochemistry Assay Human sera obtainedfrom plain tubes were tested for total cholesterol LDL HDLtriglycerides urea albumin creatinine ferritin total antiox-idant status aminotransferase aspartate (AST) and ALTHuman plasma obtained from sodium fluoride oxalate tubeswere tested for glucose Whole blood from EDTA-K3 tubewas used to determine glycated haemoglobin Using stan-dardized methods the automated Beckman Coulter AU480analyzer was used to quantify all biomarkers except totalantioxidant status which was evaluated by RX Daytona ana-lyzer All clinical biochemistry assays were completed within24 h after sample collection Serum creatinine (nonisotopedilution mass spectrometry traceable) urea and albuminwere used to estimate glomerular filtration rate (eGFR) usingthe ldquomodification of diet in renal diseaserdquo (MDRD) formula[32]

29 Statistical Analysis Parametric and nonparametric vari-ables are expressed after omitting outliers as mean plusmn stan-dard deviation and median [interquartile range] respec-tively Simple regression analysis was performed to calculate

the dose-dependent relationship of green tea extracts indifferent antioxidant assays Data derived from antioxidantassays were fitted into appropriate regressionmodel [33] (lin-ear polynomial order 2 or polynomial order 3) that allowedus to determine AA

50 Statistical inference was carried out

after omitting outliers using MedCalc for Windows (version11600 Mariakerke Belgium) Significant differences overtime within each group were determined using pairedStudentrsquos 119905-test and where data was not normal the non-parametric alternative Wilcoxon test was used Significantdifferences over time between each group were determinedusing independent samples 119905-test and where data was notnormal the nonparametric alternative Mann-Whitney testwas used The level for establishing significant differenceswas set at 10 successively Statistical analyses were alsoperformed to calculate any significant correlations betweenindividual variables daily mean calorie index and dailylipidfat ratio Pearson or Spearman rank correlation coeffi-cient was used for normally or nonnormally distributed datasets respectively Correlation analyses between individualvariables daily mean calorie index and daily lipidfat ratiowere carried out separately on week 14 and washout data setswhereby gender stratified data were taken into account Allstatistical tests were two-tailed

3 Results

31 Phytophenolic Composition of Mauritian Green Tea TheMauritian green tea phytophenolic profile is shown inTable 1 The most prominent phytophenolics in an unhy-drolyzed Mauritian green tea infusate were ranked accord-ing to their quantity per cup (200mL) in the followingdecreasing order procyanidin B2 gt (minus)-epigallocatechin

BioMed Research International 5

Table 1 Mauritian green tea phytophenolic data

Phytophenolic of unhydrolyzed Mauritian green teamg per cup(200mL)

Total phenol 23513 plusmn 3089a

Total flavonoid 752 plusmn 097b

Total proanthocyanidin 789 plusmn 063b

Procyanidin B2 49692 plusmn 2008c

(minus)-Epigallocatechin gallate 23468 plusmn 1208d

(minus)-Epigallocatechin 20512 plusmn 2542e

(minus)-Epicatechin gallate 2846 plusmn 180f

(minus)-Epicatechin 2442 plusmn 208g

(+)-Catechin 1390 plusmn 220h

Gallic acid 166 plusmn 016i

Phytophenolics in hydrolyzed Mauritian green teamg per cup(200mL)

Quercetin 150 plusmn 016j

Myricetin 148 plusmn 014j

Kaempferol 090 plusmn 008k

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant dif-ferences between mean phytophenolic contents (119875 lt 005) Free flavonoidswere not detected in the green tea extract however after hydrolysis HPLCanalysis showed that quercetin kaempferol and myricetin were the mainflavonol aglycones present in the following decreasing order quercetin gtmyricetin gt kaempferol

gallate gt (minus)-epigallocatechin gt (minus)-epicatechin gallategt (minus)-epicatechin gt (+)-catechin gt gallic acid Procyanidin B2 wasfound to be the most important compound with 49692mgper cup (200mL) while gallic acid was least prominent(166mg per cup)

32 Antioxidant Capacities of Mauritian Green Tea Thegreen tea antioxidant profile was characterized using 7 inde-pendent assays (Table 2) at concentrations varying from01 to 1mgmL A concentration ranking order indicat-ing 50 antioxidant activity (AA

50) for the green tea ex-

tract in each antioxidant assay was established as followsABTS∙+ scavenging activity (001mgmL) gt ferric reduc-ing activity (004mgmL) gt nitric oxide scavenging activ-ity (030mgmL) gt Fe2+ chelating activity (033mgmL) gtHOCL scavenging activity (039mgmL) gt superoxide scav-enging activity (042mgmL) gt DPPH scavenging activity(052mgmL) The data showed that the Mauritian greentea extract had a higher predisposition (119875 lt 005) to theABTS∙+ radical than the DPPH radical It also revealed anonsignificant (119875 gt 005) sensitivity to hypochlorous acidand superoxide anion radical Moreover Mauritian green teahad a higher affinity (119875 lt 005) to reduce Fe3+ into Fe2+ thanto chelate Fe2+

33 Clinical Trial A randomized controlled clinical trialwas conducted on humans predisposed to type 2 diabetesAmong the 300 participants that met the inclusion criteria

Table 2 Antioxidant activities of Mauritian green tea using a mul-tiassay approach

Antioxidant assays AA50 (mgmL)ABTS radical scavenging assay 001 plusmn 0001a

FRAP assay 004 plusmn 001b

Nitric oxide radical scavenging assay 030 plusmn 001c

Ferrous ions chelating assay 033 plusmn 003cd

HOCL scavenging assay 039 plusmn 003de

Superoxide radical scavenging assay 042 plusmn 001e

DPPH radical scavenging assay 052 plusmn 001f

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant differ-ences between mean AA50 (119875 lt 005) AA50 was defined as Mauritian greentea concentration that revealed a 50 antioxidant activity

155 agreed to enrol in the clinical trial and theywere randomlyallocated into the experimental and control groupThe num-ber of participants at the end of the clinical trial was 123representing a 206 dropout from initial population sizeThe final experimental and control groups consisted of 65and 58 participants respectively No subject withdrew fromthe clinical trial due to discomfort or any adverse effectsassociated with the regimen The complied dietary surveyquestionnaires showed that the daily mean calorie index anddaily lipidfat ratio remained relatively constant for both theexperimental and control groups in the male and femalepopulation during the 14-week intervention period and the2-week washout period (Figures 2 and 3) No correlationanalyses between individual variables daily mean calorieindex and daily lipidfat ratio for any group or gender turnedout to be significant nor were there any consistency in thedirection of correlations

The data in Tables 3 and 4 define the anthropometricand biochemical characteristics measured at the beginningof the study at the end of the 14-week intervention periodand after the 2-weekwashout period During the clinical trialwaist-hip ratio an indicator of obesity increased significantly(119875 lt 01) in the female control group whereas the femaleexperimental group did not experience any change on week14Mean arterial pressure defined as the average arterial pres-sure during a single cardiac cycle decreased insignificantly onweek 14 as indicated by the experimental group whereas maleand female control groups endured a critical decline of 30(119875 lt 01) and 26 (119875 lt 01) respectively

Based on the findings set out in Table 3 male subjectsunder green tea regimen showed an insignificant reduction of30 in ferritin concentration after week 14 whereas in malecontrol group its concentration rose considerably by 392(119875 lt 01) Moreover the green tea regimen did not affect thefasting plasma glucose of subjects

eGFR used to diagnose and monitor kidney functionwas estimated using the 6-variable MDRD study equationDuring the 16-week period eGFR increased insignificantlyin the male control group The male experimental groupexperienced a significant decrease of 71 (119875 lt 01) after week

6 BioMed Research International

Table3Ch

aracteris

ticso

fmalep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Maleg

reen

teag

roup

Malec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

33489plusmn69

30481plusmn79

Weight(kg)

33708plusmn136

716plusmn135

714plusmn138

30753plusmn133

759plusmn136

754plusmn134

BMI(kgm

2 )332467plusmn369

2497plusmn370(12)lowast

2487plusmn378(08)lowast

302628plusmn476

2646plusmn479(07)lowast

2623plusmn471(minus02)

Waist-

hipratio

33091plusmn006

090plusmn006(minus08)

089plusmn005(minus18

)lowast30

092plusmn005

091plusmn006(minus08)

090plusmn004(minus17

)lowastMAPa

(mmHg)

339349plusmn948

9285plusmn906(minus07)

9267plusmn1059(minus09)

299562plusmn870

9276plusmn873(minus30)lowast9229plusmn888(minus35)lowast

Glucose

(mgdL

)308970plusmn1118

9047plusmn1165(09)

9287plusmn945(35)

279056plusmn10358756plusmn1166(minus33)

8915plusmn1118(minus16

)HbA

1c(

)30

600[570ndash6

20]

590[570minus620]

605[580ndash6

30]lowast

28600[570ndash6

20]

590[560ndash6

10]lowast

595[570ndash6

10]

Cholesterol(mgdL

)3221875plusmn403919591plusmn3452(minus104)lowast19919plusmn3272(minus89)lowast

2921545plusmn400118486plusmn3534(minus142)lowast19410plusmn4206(minus99

)lowastTriglycerid

es(m

gdL

)3112542plusmn549712777plusmn5566(19)11555plusmn4838(minus79

)2612496plusmn477111558plusmn4115(minus75

)10804plusmn3881(minus135)lowast

LDL(m

gdL

)3214528plusmn337213147plusmn2853(minus95

)lowast13494plusmn2689(minus71)

2714789plusmn373412826plusmn2697(minus133)lowast13644plusmn3599(minus77

)HDL(m

gdL

)314858plusmn10924281plusmn1105(minus119)lowast4400plusmn1031(minus94

)lowast284554plusmn9413889plusmn830(minus146)lowast4086plusmn926(minus103)lowast

LDLHDL

31311plusmn085

322plusmn075(35)

322plusmn077(35)

26338plusmn103

329plusmn062(minus27)

341plusmn076(09)

Ferritin(ngdL

)2910045plusmn72689741plusmn6548(minus30)

9897plusmn6549(minus15

)268004plusmn471211142plusmn7586(392

)lowast10765plusmn7283(345)lowast

Album

in(gdL)

29450plusmn023

443plusmn020(minus14

)448plusmn020(minus05)

27450plusmn023

441plusmn023(minus21)lowast

447plusmn020(minus08)

Serum

creatin

ine(mgdL

)31

110[10

0ndash12

0]110[110ndash

120]

110[10

0ndash12

0]27

110[110ndash

120]

110[10

0ndash12

0]110[10

0ndash12

0]Urin

arycreatin

ine(mgdL

)2913152plusmn657618817plusmn9465(431)lowast17066plusmn7681(298

)lowast2913831plusmn701720038plusmn6494(449)lowast19738plusmn8027(427)lowast

Urea(

mgdL

)311442plusmn466

1465plusmn389(16)

1548plusmn394(74)

271363plusmn262

1385plusmn359(16)

1252plusmn264(minus82)lowast

eGFR

b(m

Lmin

per173m

2 )298262plusmn1673

7674plusmn900(minus71)lowast

7964plusmn1126(minus36)

278192plusmn1424

8424plusmn1379(28)

8555plusmn1535(44)

AST

c(IUL)

292635plusmn622

2641plusmn511(03)

2679plusmn554(17)

282711plusmn737

2693plusmn735(minus07)

2711plusmn721(00)

ALT

d(IUL)

322909plusmn16642706plusmn1345(minus70

)2781plusmn1139(minus44)

282825plusmn12992754plusmn1133(minus25)

2861plusmn1225(13)

TASe

(mmolL)

29160plusmn015

175plusmn011(95)lowast

192plusmn014(201)lowast

28162plusmn013

172plusmn010(62)lowast

192plusmn017(186)lowast

Hum

ansera

HT5

0(m

inutes)

281655plusmn257

1700plusmn272(27)lowast

1734plusmn265(48)lowast

281814plusmn313

1761plusmn255(minus29)

1780plusmn291(minus19

)Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereasno

nparam

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangesrelativetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

BioMed Research International 7

Table4Ch

aracteris

ticso

ffem

alep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Femaleg

reen

teag

roup

Femalec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

32493plusmn66

28469plusmn84

Weight(kg)

32613plusmn122

619plusmn124

617plusmn124

28632plusmn98

636plusmn98

637plusmn99

BMI(kgm

2 )31

2502plusmn366

2517plusmn359(06)

2507plusmn353(02)

282664plusmn329

2668plusmn334(01)

2674plusmn335(04)

Waist-

hipratio

31082plusmn005

082plusmn006(00)

084plusmn006(20)lowast

27083plusmn005

084plusmn005(18)lowast

085plusmn003(24)lowast

MAPa

(mmHg)

318880plusmn663

8774plusmn915(minus12

)8859plusmn916(minus02)

278894plusmn844

8663plusmn758(minus26)lowast

8685plusmn696(minus24)

Glucose

(mgdL

)329441plusmn1210

9484plusmn1347(05)9269plusmn1066(minus18

)28

9150plusmn970

9521plusmn1062(41)lowast

9121plusmn1169(minus03)

HbA

1c(

)30

610[590ndash6

50]

595

[580ndash

630]

610

[590ndash

640

]25

600

[578ndash610]

590

[580ndash

620]

600

[588ndash630]lowast

Cholesterol(mgdL

)3120987plusmn318119977plusmn3479(minus48)20813plusmn3711(minus08)

2820532plusmn475218879plusmn4214(minus81)lowast19404plusmn3234(minus55)lowast

Triglycerid

es(m

gdL

)3111855plusmn507311090plusmn5129(minus64)12490plusmn7412(54)

259368plusmn3353

10208plusmn3540(90)10316plusmn4548(101)

LDL(m

gdL

)3014040plusmn256812933plusmn2551(minus79

)lowast13830plusmn3003(minus15

)2713522plusmn385511663plusmn3705(minus137)lowast12882plusmn2620(minus47)

HDL(m

gdL

)315036plusmn10244842plusmn890(minus38)lowast4955plusmn920(minus16

)285207plusmn15294936plusmn1369(minus52)lowast4914plusmn1236(minus56)lowast

LDLHDL

29292plusmn083

276plusmn066(minus55)

290plusmn081(minus07)

27284plusmn125

251plusmn085(minus116)

275plusmn077(minus32)

Ferritin(ngdL

)294403plusmn36954917plusmn3675(117

)5055plusmn4501(14

8)

264273plusmn4205

4004plusmn3560(minus63)

4539plusmn4197(62)

Album

in(gdL)

29439plusmn026

435plusmn020(minus09)

445plusmn032(13)

25438plusmn016

428plusmn019(minus23)lowast

432plusmn019(minus14

)Serum

creatin

ine(mgdL

)31

090

[083ndash10

0]090

[080ndash

100]

080

[080ndash

098]lowast

28090

[080ndash

095]

090

[080ndash

090]

080

[080ndash

090]lowast

Urin

arycreatin

ine(mgdL

)309447plusmn534811163plusmn7663(182)8340plusmn6143(minus117)

239535plusmn3922

10461plusmn5790(97)8274plusmn5170(minus132)

Urea(

mgdL

)32

1147plusmn292

1163plusmn372(14)

1084plusmn284(minus54)

271063plusmn278

1007plusmn216(minus52)

989plusmn219(minus70

)eG

FRb(m

Lmin

per173m

2 )287770plusmn1600

8061plusmn1226(37)8259plusmn1175(63)lowast

278242plusmn1353

8516plusmn1364(33)

8993plusmn1365(91)lowast

AST

c(IUL)

312323plusmn492

2339plusmn472(07)

2236plusmn462(minus38)

272178plusmn536

2193plusmn498(07)

2256plusmn503(36)

ALT

d(IUL)

291800plusmn6721566plusmn369(minus130)lowast1621plusmn502(minus100)lowast

261739plusmn673

1619plusmn467(minus69)

1627plusmn534(minus64)

TASe

(mmolL)

29148plusmn011

166plusmn011(119

)lowast177plusmn009(19

6)lowast

24148plusmn011

160plusmn008(83)lowast

179plusmn015(211)lowast

Hum

ansera

HT5

0(m

inutes)

311600plusmn323

1682plusmn323(51)lowast

1657plusmn324(36)lowast

261601plusmn335

1586plusmn261(minus09)

1597plusmn307(minus02)

Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereas

nonp

aram

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangerela

tivetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

8 BioMed Research International

0100020003000400050006000700080009000

Mea

n ca

lorie

inde

xda

y (a

u)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

Figure 2 Daily mean calorie index variation for participants undergreen tea and water regimen during the 14-week interventionperiod and 2-week washout period in a male and female MauritianpopulationMain and error bars representmean values and standarddeviations respectively for experimental group (male 119899 = 33female 119899 = 32) and control group (male 119899 = 30 female 119899 = 28)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

0

100

200

300

400

500

600

Lipi

dfa

t rat

iod

ay (a

u)

Figure 3 Daily lipidfat ratio for participants under green teaand water regimen during the 14-week intervention period and 2-week washout period in a male and female Mauritian populationMain and error bars represent mean values and standard deviationsrespectively for experimental group (male 119899 = 33 female 119899 = 32)and control group (male 119899 = 30 female 119899 = 28)

14 followed by a critical increase of 38 (119875 lt 01) (relativeto week 14 value) after the washout period

The ALT a transaminase enzyme used to determineliver health decreased significantly by 130 (119875 lt 01) asillustrated by the female experimental group on week 14whereas female control group did not show any significantchange throughout the clinical trial The time taken forhuman sera to delay hemolysis by 50 representing theantioxidant potential of human sera at the cellular levelincreased significantly by 27 (119875 lt 01) and 51 (119875 lt 01) inmale and female experimental groups respectively afterweek14 whereas their corresponding control groups experienceda decrease

0

100

200

300

400

500

Control 025 050 100 150Tim

e tak

en fo

r 50

hem

olys

is to

occ

ur

HT5

0 (m

inut

es)

lowastlowastlowast

lowastlowastlowast

lowastlowastlowast

Green tea extracts (mgmL)

Figure 4 The prophylactic effect of green tea extracts against freeradical which might be a causative agent of metabolic syndromeMain and error bars represent mean value and standard deviationof three independent experiments respectively Statistical analyseswere performed using independent samples 119905-test for multiplecomparisons lowastlowastlowastTime taken for 50 hemolysis to occur wassignificantly different from that of control (119875 lt 001)

4 Discussion

The current management of type 2 diabetes involves acombination of dietary plans exercise programs and the useof drugs such as sulfonylureas and biguanide [34] Besidesthese conventional therapies a growing body of evidencehas indicated the role of green tea polyphenols in improvingfeatures of metabolic syndrome and subsequent risks fordiabetes and its complications [1 35] The putative beneficialeffects ascribed to green tea polyphenols are partly mediatedby their free radical scavenging antioxidant action and abil-ity to form complexes withmetal ionsThe green tea analysedin this study had high levels of total phenols flavonoids andproanthocyanidins with a wide range individual compoundsthat synergistically contributed to the antioxidative propen-sity of the extract as evidenced by the multiantioxidant anal-ysis data including the free radical-induced hemolysis assaydata (Figure 4) Similar observations were made in an earlierreport where green and black teas were characterised for theirantioxidant functions [36] The green tea supplementation inthis study led to a significant increase in serum antioxidantcapacity as measured by the free radical-induced hemolysisassay This suggests that the oxidative stress condition thatcan be encountered in diabetes [3 4] could benefit fromgreen tea consumption Raza and John [37] have reportedthat tea catechins can prevent protein degradation by alteringsubcellular reactive oxygen species production glutathionemetabolism and cytochrome P450 2E1 activity Grinberget al [38] found that tea polyphenols protect red blood cellsagainst primaquine-induced lysis and H

2O2-induced lipid

peroxidation While it can be further derived from the datain this study that green tea consumption can reinforce invivo antioxidant defences the potential prophylactic effectsof green tea against diabetes and its complications remain tobe clearly defined In the study the effect of cigarette smokingexcessive alcohol intake and hormone replacement therapyon levels of biomarkers measured were minimised by theexclusion criteria applied to the subject population Dietary

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

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Diabetes ResearchJournal of

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Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

4 BioMed Research International

145 declined to participate

155 randomly allocated to

Experimental group(male n = 40 female n = 37)

Control group(male n = 43 female n = 35)

Completed 16-week period(male n = 33 female n = 32) (male n = 30 female n = 28)

300 participants met inclusion criteria and were invited to participate in the clinical study

Green tea regimen1 cup of green tea 3 times a day before

meals for 14 weeks

Water regimen1 cup of warm water 3 times a day before

meals for 14 weeks

Washout period1 cup of warm water 3 times a day before

meals for 2 weeks1 cup of warm water 3 times a day before

meals for 2 weeks

intervention12 lost to followup or discontinued 12 lost to followup or discontinued

intervention

Washout period

Completed 16-week period

Figure 1 Flow diagram showing trial profile and study design

into EDTA-K3 tube sodium fluoride oxalate tube and plaintubes Biological samples were kept at 4∘C and transportedfor analysis to Apollo Bramwell Hospital Moka Republicof Mauritius Before conducting any assays all tubes werecentrifuged at 3000 rpm for 7min at 25∘C with the exceptionof EDTA-K3 tube Human sera from plain tubes were usedfor free radical-induced hemolysis and clinical biochemistryassay Whole blood from EDTA-K3 tubes and human plasmafrom sodiumfluoride oxalate tubeswere used only for clinicalbiochemistry assay

286 Clinical Biochemistry Assay Human sera obtainedfrom plain tubes were tested for total cholesterol LDL HDLtriglycerides urea albumin creatinine ferritin total antiox-idant status aminotransferase aspartate (AST) and ALTHuman plasma obtained from sodium fluoride oxalate tubeswere tested for glucose Whole blood from EDTA-K3 tubewas used to determine glycated haemoglobin Using stan-dardized methods the automated Beckman Coulter AU480analyzer was used to quantify all biomarkers except totalantioxidant status which was evaluated by RX Daytona ana-lyzer All clinical biochemistry assays were completed within24 h after sample collection Serum creatinine (nonisotopedilution mass spectrometry traceable) urea and albuminwere used to estimate glomerular filtration rate (eGFR) usingthe ldquomodification of diet in renal diseaserdquo (MDRD) formula[32]

29 Statistical Analysis Parametric and nonparametric vari-ables are expressed after omitting outliers as mean plusmn stan-dard deviation and median [interquartile range] respec-tively Simple regression analysis was performed to calculate

the dose-dependent relationship of green tea extracts indifferent antioxidant assays Data derived from antioxidantassays were fitted into appropriate regressionmodel [33] (lin-ear polynomial order 2 or polynomial order 3) that allowedus to determine AA

50 Statistical inference was carried out

after omitting outliers using MedCalc for Windows (version11600 Mariakerke Belgium) Significant differences overtime within each group were determined using pairedStudentrsquos 119905-test and where data was not normal the non-parametric alternative Wilcoxon test was used Significantdifferences over time between each group were determinedusing independent samples 119905-test and where data was notnormal the nonparametric alternative Mann-Whitney testwas used The level for establishing significant differenceswas set at 10 successively Statistical analyses were alsoperformed to calculate any significant correlations betweenindividual variables daily mean calorie index and dailylipidfat ratio Pearson or Spearman rank correlation coeffi-cient was used for normally or nonnormally distributed datasets respectively Correlation analyses between individualvariables daily mean calorie index and daily lipidfat ratiowere carried out separately on week 14 and washout data setswhereby gender stratified data were taken into account Allstatistical tests were two-tailed

3 Results

31 Phytophenolic Composition of Mauritian Green Tea TheMauritian green tea phytophenolic profile is shown inTable 1 The most prominent phytophenolics in an unhy-drolyzed Mauritian green tea infusate were ranked accord-ing to their quantity per cup (200mL) in the followingdecreasing order procyanidin B2 gt (minus)-epigallocatechin

BioMed Research International 5

Table 1 Mauritian green tea phytophenolic data

Phytophenolic of unhydrolyzed Mauritian green teamg per cup(200mL)

Total phenol 23513 plusmn 3089a

Total flavonoid 752 plusmn 097b

Total proanthocyanidin 789 plusmn 063b

Procyanidin B2 49692 plusmn 2008c

(minus)-Epigallocatechin gallate 23468 plusmn 1208d

(minus)-Epigallocatechin 20512 plusmn 2542e

(minus)-Epicatechin gallate 2846 plusmn 180f

(minus)-Epicatechin 2442 plusmn 208g

(+)-Catechin 1390 plusmn 220h

Gallic acid 166 plusmn 016i

Phytophenolics in hydrolyzed Mauritian green teamg per cup(200mL)

Quercetin 150 plusmn 016j

Myricetin 148 plusmn 014j

Kaempferol 090 plusmn 008k

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant dif-ferences between mean phytophenolic contents (119875 lt 005) Free flavonoidswere not detected in the green tea extract however after hydrolysis HPLCanalysis showed that quercetin kaempferol and myricetin were the mainflavonol aglycones present in the following decreasing order quercetin gtmyricetin gt kaempferol

gallate gt (minus)-epigallocatechin gt (minus)-epicatechin gallategt (minus)-epicatechin gt (+)-catechin gt gallic acid Procyanidin B2 wasfound to be the most important compound with 49692mgper cup (200mL) while gallic acid was least prominent(166mg per cup)

32 Antioxidant Capacities of Mauritian Green Tea Thegreen tea antioxidant profile was characterized using 7 inde-pendent assays (Table 2) at concentrations varying from01 to 1mgmL A concentration ranking order indicat-ing 50 antioxidant activity (AA

50) for the green tea ex-

tract in each antioxidant assay was established as followsABTS∙+ scavenging activity (001mgmL) gt ferric reduc-ing activity (004mgmL) gt nitric oxide scavenging activ-ity (030mgmL) gt Fe2+ chelating activity (033mgmL) gtHOCL scavenging activity (039mgmL) gt superoxide scav-enging activity (042mgmL) gt DPPH scavenging activity(052mgmL) The data showed that the Mauritian greentea extract had a higher predisposition (119875 lt 005) to theABTS∙+ radical than the DPPH radical It also revealed anonsignificant (119875 gt 005) sensitivity to hypochlorous acidand superoxide anion radical Moreover Mauritian green teahad a higher affinity (119875 lt 005) to reduce Fe3+ into Fe2+ thanto chelate Fe2+

33 Clinical Trial A randomized controlled clinical trialwas conducted on humans predisposed to type 2 diabetesAmong the 300 participants that met the inclusion criteria

Table 2 Antioxidant activities of Mauritian green tea using a mul-tiassay approach

Antioxidant assays AA50 (mgmL)ABTS radical scavenging assay 001 plusmn 0001a

FRAP assay 004 plusmn 001b

Nitric oxide radical scavenging assay 030 plusmn 001c

Ferrous ions chelating assay 033 plusmn 003cd

HOCL scavenging assay 039 plusmn 003de

Superoxide radical scavenging assay 042 plusmn 001e

DPPH radical scavenging assay 052 plusmn 001f

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant differ-ences between mean AA50 (119875 lt 005) AA50 was defined as Mauritian greentea concentration that revealed a 50 antioxidant activity

155 agreed to enrol in the clinical trial and theywere randomlyallocated into the experimental and control groupThe num-ber of participants at the end of the clinical trial was 123representing a 206 dropout from initial population sizeThe final experimental and control groups consisted of 65and 58 participants respectively No subject withdrew fromthe clinical trial due to discomfort or any adverse effectsassociated with the regimen The complied dietary surveyquestionnaires showed that the daily mean calorie index anddaily lipidfat ratio remained relatively constant for both theexperimental and control groups in the male and femalepopulation during the 14-week intervention period and the2-week washout period (Figures 2 and 3) No correlationanalyses between individual variables daily mean calorieindex and daily lipidfat ratio for any group or gender turnedout to be significant nor were there any consistency in thedirection of correlations

The data in Tables 3 and 4 define the anthropometricand biochemical characteristics measured at the beginningof the study at the end of the 14-week intervention periodand after the 2-weekwashout period During the clinical trialwaist-hip ratio an indicator of obesity increased significantly(119875 lt 01) in the female control group whereas the femaleexperimental group did not experience any change on week14Mean arterial pressure defined as the average arterial pres-sure during a single cardiac cycle decreased insignificantly onweek 14 as indicated by the experimental group whereas maleand female control groups endured a critical decline of 30(119875 lt 01) and 26 (119875 lt 01) respectively

Based on the findings set out in Table 3 male subjectsunder green tea regimen showed an insignificant reduction of30 in ferritin concentration after week 14 whereas in malecontrol group its concentration rose considerably by 392(119875 lt 01) Moreover the green tea regimen did not affect thefasting plasma glucose of subjects

eGFR used to diagnose and monitor kidney functionwas estimated using the 6-variable MDRD study equationDuring the 16-week period eGFR increased insignificantlyin the male control group The male experimental groupexperienced a significant decrease of 71 (119875 lt 01) after week

6 BioMed Research International

Table3Ch

aracteris

ticso

fmalep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Maleg

reen

teag

roup

Malec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

33489plusmn69

30481plusmn79

Weight(kg)

33708plusmn136

716plusmn135

714plusmn138

30753plusmn133

759plusmn136

754plusmn134

BMI(kgm

2 )332467plusmn369

2497plusmn370(12)lowast

2487plusmn378(08)lowast

302628plusmn476

2646plusmn479(07)lowast

2623plusmn471(minus02)

Waist-

hipratio

33091plusmn006

090plusmn006(minus08)

089plusmn005(minus18

)lowast30

092plusmn005

091plusmn006(minus08)

090plusmn004(minus17

)lowastMAPa

(mmHg)

339349plusmn948

9285plusmn906(minus07)

9267plusmn1059(minus09)

299562plusmn870

9276plusmn873(minus30)lowast9229plusmn888(minus35)lowast

Glucose

(mgdL

)308970plusmn1118

9047plusmn1165(09)

9287plusmn945(35)

279056plusmn10358756plusmn1166(minus33)

8915plusmn1118(minus16

)HbA

1c(

)30

600[570ndash6

20]

590[570minus620]

605[580ndash6

30]lowast

28600[570ndash6

20]

590[560ndash6

10]lowast

595[570ndash6

10]

Cholesterol(mgdL

)3221875plusmn403919591plusmn3452(minus104)lowast19919plusmn3272(minus89)lowast

2921545plusmn400118486plusmn3534(minus142)lowast19410plusmn4206(minus99

)lowastTriglycerid

es(m

gdL

)3112542plusmn549712777plusmn5566(19)11555plusmn4838(minus79

)2612496plusmn477111558plusmn4115(minus75

)10804plusmn3881(minus135)lowast

LDL(m

gdL

)3214528plusmn337213147plusmn2853(minus95

)lowast13494plusmn2689(minus71)

2714789plusmn373412826plusmn2697(minus133)lowast13644plusmn3599(minus77

)HDL(m

gdL

)314858plusmn10924281plusmn1105(minus119)lowast4400plusmn1031(minus94

)lowast284554plusmn9413889plusmn830(minus146)lowast4086plusmn926(minus103)lowast

LDLHDL

31311plusmn085

322plusmn075(35)

322plusmn077(35)

26338plusmn103

329plusmn062(minus27)

341plusmn076(09)

Ferritin(ngdL

)2910045plusmn72689741plusmn6548(minus30)

9897plusmn6549(minus15

)268004plusmn471211142plusmn7586(392

)lowast10765plusmn7283(345)lowast

Album

in(gdL)

29450plusmn023

443plusmn020(minus14

)448plusmn020(minus05)

27450plusmn023

441plusmn023(minus21)lowast

447plusmn020(minus08)

Serum

creatin

ine(mgdL

)31

110[10

0ndash12

0]110[110ndash

120]

110[10

0ndash12

0]27

110[110ndash

120]

110[10

0ndash12

0]110[10

0ndash12

0]Urin

arycreatin

ine(mgdL

)2913152plusmn657618817plusmn9465(431)lowast17066plusmn7681(298

)lowast2913831plusmn701720038plusmn6494(449)lowast19738plusmn8027(427)lowast

Urea(

mgdL

)311442plusmn466

1465plusmn389(16)

1548plusmn394(74)

271363plusmn262

1385plusmn359(16)

1252plusmn264(minus82)lowast

eGFR

b(m

Lmin

per173m

2 )298262plusmn1673

7674plusmn900(minus71)lowast

7964plusmn1126(minus36)

278192plusmn1424

8424plusmn1379(28)

8555plusmn1535(44)

AST

c(IUL)

292635plusmn622

2641plusmn511(03)

2679plusmn554(17)

282711plusmn737

2693plusmn735(minus07)

2711plusmn721(00)

ALT

d(IUL)

322909plusmn16642706plusmn1345(minus70

)2781plusmn1139(minus44)

282825plusmn12992754plusmn1133(minus25)

2861plusmn1225(13)

TASe

(mmolL)

29160plusmn015

175plusmn011(95)lowast

192plusmn014(201)lowast

28162plusmn013

172plusmn010(62)lowast

192plusmn017(186)lowast

Hum

ansera

HT5

0(m

inutes)

281655plusmn257

1700plusmn272(27)lowast

1734plusmn265(48)lowast

281814plusmn313

1761plusmn255(minus29)

1780plusmn291(minus19

)Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereasno

nparam

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangesrelativetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

BioMed Research International 7

Table4Ch

aracteris

ticso

ffem

alep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Femaleg

reen

teag

roup

Femalec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

32493plusmn66

28469plusmn84

Weight(kg)

32613plusmn122

619plusmn124

617plusmn124

28632plusmn98

636plusmn98

637plusmn99

BMI(kgm

2 )31

2502plusmn366

2517plusmn359(06)

2507plusmn353(02)

282664plusmn329

2668plusmn334(01)

2674plusmn335(04)

Waist-

hipratio

31082plusmn005

082plusmn006(00)

084plusmn006(20)lowast

27083plusmn005

084plusmn005(18)lowast

085plusmn003(24)lowast

MAPa

(mmHg)

318880plusmn663

8774plusmn915(minus12

)8859plusmn916(minus02)

278894plusmn844

8663plusmn758(minus26)lowast

8685plusmn696(minus24)

Glucose

(mgdL

)329441plusmn1210

9484plusmn1347(05)9269plusmn1066(minus18

)28

9150plusmn970

9521plusmn1062(41)lowast

9121plusmn1169(minus03)

HbA

1c(

)30

610[590ndash6

50]

595

[580ndash

630]

610

[590ndash

640

]25

600

[578ndash610]

590

[580ndash

620]

600

[588ndash630]lowast

Cholesterol(mgdL

)3120987plusmn318119977plusmn3479(minus48)20813plusmn3711(minus08)

2820532plusmn475218879plusmn4214(minus81)lowast19404plusmn3234(minus55)lowast

Triglycerid

es(m

gdL

)3111855plusmn507311090plusmn5129(minus64)12490plusmn7412(54)

259368plusmn3353

10208plusmn3540(90)10316plusmn4548(101)

LDL(m

gdL

)3014040plusmn256812933plusmn2551(minus79

)lowast13830plusmn3003(minus15

)2713522plusmn385511663plusmn3705(minus137)lowast12882plusmn2620(minus47)

HDL(m

gdL

)315036plusmn10244842plusmn890(minus38)lowast4955plusmn920(minus16

)285207plusmn15294936plusmn1369(minus52)lowast4914plusmn1236(minus56)lowast

LDLHDL

29292plusmn083

276plusmn066(minus55)

290plusmn081(minus07)

27284plusmn125

251plusmn085(minus116)

275plusmn077(minus32)

Ferritin(ngdL

)294403plusmn36954917plusmn3675(117

)5055plusmn4501(14

8)

264273plusmn4205

4004plusmn3560(minus63)

4539plusmn4197(62)

Album

in(gdL)

29439plusmn026

435plusmn020(minus09)

445plusmn032(13)

25438plusmn016

428plusmn019(minus23)lowast

432plusmn019(minus14

)Serum

creatin

ine(mgdL

)31

090

[083ndash10

0]090

[080ndash

100]

080

[080ndash

098]lowast

28090

[080ndash

095]

090

[080ndash

090]

080

[080ndash

090]lowast

Urin

arycreatin

ine(mgdL

)309447plusmn534811163plusmn7663(182)8340plusmn6143(minus117)

239535plusmn3922

10461plusmn5790(97)8274plusmn5170(minus132)

Urea(

mgdL

)32

1147plusmn292

1163plusmn372(14)

1084plusmn284(minus54)

271063plusmn278

1007plusmn216(minus52)

989plusmn219(minus70

)eG

FRb(m

Lmin

per173m

2 )287770plusmn1600

8061plusmn1226(37)8259plusmn1175(63)lowast

278242plusmn1353

8516plusmn1364(33)

8993plusmn1365(91)lowast

AST

c(IUL)

312323plusmn492

2339plusmn472(07)

2236plusmn462(minus38)

272178plusmn536

2193plusmn498(07)

2256plusmn503(36)

ALT

d(IUL)

291800plusmn6721566plusmn369(minus130)lowast1621plusmn502(minus100)lowast

261739plusmn673

1619plusmn467(minus69)

1627plusmn534(minus64)

TASe

(mmolL)

29148plusmn011

166plusmn011(119

)lowast177plusmn009(19

6)lowast

24148plusmn011

160plusmn008(83)lowast

179plusmn015(211)lowast

Hum

ansera

HT5

0(m

inutes)

311600plusmn323

1682plusmn323(51)lowast

1657plusmn324(36)lowast

261601plusmn335

1586plusmn261(minus09)

1597plusmn307(minus02)

Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereas

nonp

aram

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangerela

tivetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

8 BioMed Research International

0100020003000400050006000700080009000

Mea

n ca

lorie

inde

xda

y (a

u)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

Figure 2 Daily mean calorie index variation for participants undergreen tea and water regimen during the 14-week interventionperiod and 2-week washout period in a male and female MauritianpopulationMain and error bars representmean values and standarddeviations respectively for experimental group (male 119899 = 33female 119899 = 32) and control group (male 119899 = 30 female 119899 = 28)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

0

100

200

300

400

500

600

Lipi

dfa

t rat

iod

ay (a

u)

Figure 3 Daily lipidfat ratio for participants under green teaand water regimen during the 14-week intervention period and 2-week washout period in a male and female Mauritian populationMain and error bars represent mean values and standard deviationsrespectively for experimental group (male 119899 = 33 female 119899 = 32)and control group (male 119899 = 30 female 119899 = 28)

14 followed by a critical increase of 38 (119875 lt 01) (relativeto week 14 value) after the washout period

The ALT a transaminase enzyme used to determineliver health decreased significantly by 130 (119875 lt 01) asillustrated by the female experimental group on week 14whereas female control group did not show any significantchange throughout the clinical trial The time taken forhuman sera to delay hemolysis by 50 representing theantioxidant potential of human sera at the cellular levelincreased significantly by 27 (119875 lt 01) and 51 (119875 lt 01) inmale and female experimental groups respectively afterweek14 whereas their corresponding control groups experienceda decrease

0

100

200

300

400

500

Control 025 050 100 150Tim

e tak

en fo

r 50

hem

olys

is to

occ

ur

HT5

0 (m

inut

es)

lowastlowastlowast

lowastlowastlowast

lowastlowastlowast

Green tea extracts (mgmL)

Figure 4 The prophylactic effect of green tea extracts against freeradical which might be a causative agent of metabolic syndromeMain and error bars represent mean value and standard deviationof three independent experiments respectively Statistical analyseswere performed using independent samples 119905-test for multiplecomparisons lowastlowastlowastTime taken for 50 hemolysis to occur wassignificantly different from that of control (119875 lt 001)

4 Discussion

The current management of type 2 diabetes involves acombination of dietary plans exercise programs and the useof drugs such as sulfonylureas and biguanide [34] Besidesthese conventional therapies a growing body of evidencehas indicated the role of green tea polyphenols in improvingfeatures of metabolic syndrome and subsequent risks fordiabetes and its complications [1 35] The putative beneficialeffects ascribed to green tea polyphenols are partly mediatedby their free radical scavenging antioxidant action and abil-ity to form complexes withmetal ionsThe green tea analysedin this study had high levels of total phenols flavonoids andproanthocyanidins with a wide range individual compoundsthat synergistically contributed to the antioxidative propen-sity of the extract as evidenced by the multiantioxidant anal-ysis data including the free radical-induced hemolysis assaydata (Figure 4) Similar observations were made in an earlierreport where green and black teas were characterised for theirantioxidant functions [36] The green tea supplementation inthis study led to a significant increase in serum antioxidantcapacity as measured by the free radical-induced hemolysisassay This suggests that the oxidative stress condition thatcan be encountered in diabetes [3 4] could benefit fromgreen tea consumption Raza and John [37] have reportedthat tea catechins can prevent protein degradation by alteringsubcellular reactive oxygen species production glutathionemetabolism and cytochrome P450 2E1 activity Grinberget al [38] found that tea polyphenols protect red blood cellsagainst primaquine-induced lysis and H

2O2-induced lipid

peroxidation While it can be further derived from the datain this study that green tea consumption can reinforce invivo antioxidant defences the potential prophylactic effectsof green tea against diabetes and its complications remain tobe clearly defined In the study the effect of cigarette smokingexcessive alcohol intake and hormone replacement therapyon levels of biomarkers measured were minimised by theexclusion criteria applied to the subject population Dietary

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

BioMed Research International 5

Table 1 Mauritian green tea phytophenolic data

Phytophenolic of unhydrolyzed Mauritian green teamg per cup(200mL)

Total phenol 23513 plusmn 3089a

Total flavonoid 752 plusmn 097b

Total proanthocyanidin 789 plusmn 063b

Procyanidin B2 49692 plusmn 2008c

(minus)-Epigallocatechin gallate 23468 plusmn 1208d

(minus)-Epigallocatechin 20512 plusmn 2542e

(minus)-Epicatechin gallate 2846 plusmn 180f

(minus)-Epicatechin 2442 plusmn 208g

(+)-Catechin 1390 plusmn 220h

Gallic acid 166 plusmn 016i

Phytophenolics in hydrolyzed Mauritian green teamg per cup(200mL)

Quercetin 150 plusmn 016j

Myricetin 148 plusmn 014j

Kaempferol 090 plusmn 008k

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant dif-ferences between mean phytophenolic contents (119875 lt 005) Free flavonoidswere not detected in the green tea extract however after hydrolysis HPLCanalysis showed that quercetin kaempferol and myricetin were the mainflavonol aglycones present in the following decreasing order quercetin gtmyricetin gt kaempferol

gallate gt (minus)-epigallocatechin gt (minus)-epicatechin gallategt (minus)-epicatechin gt (+)-catechin gt gallic acid Procyanidin B2 wasfound to be the most important compound with 49692mgper cup (200mL) while gallic acid was least prominent(166mg per cup)

32 Antioxidant Capacities of Mauritian Green Tea Thegreen tea antioxidant profile was characterized using 7 inde-pendent assays (Table 2) at concentrations varying from01 to 1mgmL A concentration ranking order indicat-ing 50 antioxidant activity (AA

50) for the green tea ex-

tract in each antioxidant assay was established as followsABTS∙+ scavenging activity (001mgmL) gt ferric reduc-ing activity (004mgmL) gt nitric oxide scavenging activ-ity (030mgmL) gt Fe2+ chelating activity (033mgmL) gtHOCL scavenging activity (039mgmL) gt superoxide scav-enging activity (042mgmL) gt DPPH scavenging activity(052mgmL) The data showed that the Mauritian greentea extract had a higher predisposition (119875 lt 005) to theABTS∙+ radical than the DPPH radical It also revealed anonsignificant (119875 gt 005) sensitivity to hypochlorous acidand superoxide anion radical Moreover Mauritian green teahad a higher affinity (119875 lt 005) to reduce Fe3+ into Fe2+ thanto chelate Fe2+

33 Clinical Trial A randomized controlled clinical trialwas conducted on humans predisposed to type 2 diabetesAmong the 300 participants that met the inclusion criteria

Table 2 Antioxidant activities of Mauritian green tea using a mul-tiassay approach

Antioxidant assays AA50 (mgmL)ABTS radical scavenging assay 001 plusmn 0001a

FRAP assay 004 plusmn 001b

Nitric oxide radical scavenging assay 030 plusmn 001c

Ferrous ions chelating assay 033 plusmn 003cd

HOCL scavenging assay 039 plusmn 003de

Superoxide radical scavenging assay 042 plusmn 001e

DPPH radical scavenging assay 052 plusmn 001f

Data are expressed as mean plusmn standard deviation (119899 = 3) Statistical analyseswere performed using independent samples t-test formultiple comparisonsDifferent alphabetical superscripts between rows represent significant differ-ences between mean AA50 (119875 lt 005) AA50 was defined as Mauritian greentea concentration that revealed a 50 antioxidant activity

155 agreed to enrol in the clinical trial and theywere randomlyallocated into the experimental and control groupThe num-ber of participants at the end of the clinical trial was 123representing a 206 dropout from initial population sizeThe final experimental and control groups consisted of 65and 58 participants respectively No subject withdrew fromthe clinical trial due to discomfort or any adverse effectsassociated with the regimen The complied dietary surveyquestionnaires showed that the daily mean calorie index anddaily lipidfat ratio remained relatively constant for both theexperimental and control groups in the male and femalepopulation during the 14-week intervention period and the2-week washout period (Figures 2 and 3) No correlationanalyses between individual variables daily mean calorieindex and daily lipidfat ratio for any group or gender turnedout to be significant nor were there any consistency in thedirection of correlations

The data in Tables 3 and 4 define the anthropometricand biochemical characteristics measured at the beginningof the study at the end of the 14-week intervention periodand after the 2-weekwashout period During the clinical trialwaist-hip ratio an indicator of obesity increased significantly(119875 lt 01) in the female control group whereas the femaleexperimental group did not experience any change on week14Mean arterial pressure defined as the average arterial pres-sure during a single cardiac cycle decreased insignificantly onweek 14 as indicated by the experimental group whereas maleand female control groups endured a critical decline of 30(119875 lt 01) and 26 (119875 lt 01) respectively

Based on the findings set out in Table 3 male subjectsunder green tea regimen showed an insignificant reduction of30 in ferritin concentration after week 14 whereas in malecontrol group its concentration rose considerably by 392(119875 lt 01) Moreover the green tea regimen did not affect thefasting plasma glucose of subjects

eGFR used to diagnose and monitor kidney functionwas estimated using the 6-variable MDRD study equationDuring the 16-week period eGFR increased insignificantlyin the male control group The male experimental groupexperienced a significant decrease of 71 (119875 lt 01) after week

6 BioMed Research International

Table3Ch

aracteris

ticso

fmalep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Maleg

reen

teag

roup

Malec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

33489plusmn69

30481plusmn79

Weight(kg)

33708plusmn136

716plusmn135

714plusmn138

30753plusmn133

759plusmn136

754plusmn134

BMI(kgm

2 )332467plusmn369

2497plusmn370(12)lowast

2487plusmn378(08)lowast

302628plusmn476

2646plusmn479(07)lowast

2623plusmn471(minus02)

Waist-

hipratio

33091plusmn006

090plusmn006(minus08)

089plusmn005(minus18

)lowast30

092plusmn005

091plusmn006(minus08)

090plusmn004(minus17

)lowastMAPa

(mmHg)

339349plusmn948

9285plusmn906(minus07)

9267plusmn1059(minus09)

299562plusmn870

9276plusmn873(minus30)lowast9229plusmn888(minus35)lowast

Glucose

(mgdL

)308970plusmn1118

9047plusmn1165(09)

9287plusmn945(35)

279056plusmn10358756plusmn1166(minus33)

8915plusmn1118(minus16

)HbA

1c(

)30

600[570ndash6

20]

590[570minus620]

605[580ndash6

30]lowast

28600[570ndash6

20]

590[560ndash6

10]lowast

595[570ndash6

10]

Cholesterol(mgdL

)3221875plusmn403919591plusmn3452(minus104)lowast19919plusmn3272(minus89)lowast

2921545plusmn400118486plusmn3534(minus142)lowast19410plusmn4206(minus99

)lowastTriglycerid

es(m

gdL

)3112542plusmn549712777plusmn5566(19)11555plusmn4838(minus79

)2612496plusmn477111558plusmn4115(minus75

)10804plusmn3881(minus135)lowast

LDL(m

gdL

)3214528plusmn337213147plusmn2853(minus95

)lowast13494plusmn2689(minus71)

2714789plusmn373412826plusmn2697(minus133)lowast13644plusmn3599(minus77

)HDL(m

gdL

)314858plusmn10924281plusmn1105(minus119)lowast4400plusmn1031(minus94

)lowast284554plusmn9413889plusmn830(minus146)lowast4086plusmn926(minus103)lowast

LDLHDL

31311plusmn085

322plusmn075(35)

322plusmn077(35)

26338plusmn103

329plusmn062(minus27)

341plusmn076(09)

Ferritin(ngdL

)2910045plusmn72689741plusmn6548(minus30)

9897plusmn6549(minus15

)268004plusmn471211142plusmn7586(392

)lowast10765plusmn7283(345)lowast

Album

in(gdL)

29450plusmn023

443plusmn020(minus14

)448plusmn020(minus05)

27450plusmn023

441plusmn023(minus21)lowast

447plusmn020(minus08)

Serum

creatin

ine(mgdL

)31

110[10

0ndash12

0]110[110ndash

120]

110[10

0ndash12

0]27

110[110ndash

120]

110[10

0ndash12

0]110[10

0ndash12

0]Urin

arycreatin

ine(mgdL

)2913152plusmn657618817plusmn9465(431)lowast17066plusmn7681(298

)lowast2913831plusmn701720038plusmn6494(449)lowast19738plusmn8027(427)lowast

Urea(

mgdL

)311442plusmn466

1465plusmn389(16)

1548plusmn394(74)

271363plusmn262

1385plusmn359(16)

1252plusmn264(minus82)lowast

eGFR

b(m

Lmin

per173m

2 )298262plusmn1673

7674plusmn900(minus71)lowast

7964plusmn1126(minus36)

278192plusmn1424

8424plusmn1379(28)

8555plusmn1535(44)

AST

c(IUL)

292635plusmn622

2641plusmn511(03)

2679plusmn554(17)

282711plusmn737

2693plusmn735(minus07)

2711plusmn721(00)

ALT

d(IUL)

322909plusmn16642706plusmn1345(minus70

)2781plusmn1139(minus44)

282825plusmn12992754plusmn1133(minus25)

2861plusmn1225(13)

TASe

(mmolL)

29160plusmn015

175plusmn011(95)lowast

192plusmn014(201)lowast

28162plusmn013

172plusmn010(62)lowast

192plusmn017(186)lowast

Hum

ansera

HT5

0(m

inutes)

281655plusmn257

1700plusmn272(27)lowast

1734plusmn265(48)lowast

281814plusmn313

1761plusmn255(minus29)

1780plusmn291(minus19

)Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereasno

nparam

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangesrelativetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

BioMed Research International 7

Table4Ch

aracteris

ticso

ffem

alep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Femaleg

reen

teag

roup

Femalec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

32493plusmn66

28469plusmn84

Weight(kg)

32613plusmn122

619plusmn124

617plusmn124

28632plusmn98

636plusmn98

637plusmn99

BMI(kgm

2 )31

2502plusmn366

2517plusmn359(06)

2507plusmn353(02)

282664plusmn329

2668plusmn334(01)

2674plusmn335(04)

Waist-

hipratio

31082plusmn005

082plusmn006(00)

084plusmn006(20)lowast

27083plusmn005

084plusmn005(18)lowast

085plusmn003(24)lowast

MAPa

(mmHg)

318880plusmn663

8774plusmn915(minus12

)8859plusmn916(minus02)

278894plusmn844

8663plusmn758(minus26)lowast

8685plusmn696(minus24)

Glucose

(mgdL

)329441plusmn1210

9484plusmn1347(05)9269plusmn1066(minus18

)28

9150plusmn970

9521plusmn1062(41)lowast

9121plusmn1169(minus03)

HbA

1c(

)30

610[590ndash6

50]

595

[580ndash

630]

610

[590ndash

640

]25

600

[578ndash610]

590

[580ndash

620]

600

[588ndash630]lowast

Cholesterol(mgdL

)3120987plusmn318119977plusmn3479(minus48)20813plusmn3711(minus08)

2820532plusmn475218879plusmn4214(minus81)lowast19404plusmn3234(minus55)lowast

Triglycerid

es(m

gdL

)3111855plusmn507311090plusmn5129(minus64)12490plusmn7412(54)

259368plusmn3353

10208plusmn3540(90)10316plusmn4548(101)

LDL(m

gdL

)3014040plusmn256812933plusmn2551(minus79

)lowast13830plusmn3003(minus15

)2713522plusmn385511663plusmn3705(minus137)lowast12882plusmn2620(minus47)

HDL(m

gdL

)315036plusmn10244842plusmn890(minus38)lowast4955plusmn920(minus16

)285207plusmn15294936plusmn1369(minus52)lowast4914plusmn1236(minus56)lowast

LDLHDL

29292plusmn083

276plusmn066(minus55)

290plusmn081(minus07)

27284plusmn125

251plusmn085(minus116)

275plusmn077(minus32)

Ferritin(ngdL

)294403plusmn36954917plusmn3675(117

)5055plusmn4501(14

8)

264273plusmn4205

4004plusmn3560(minus63)

4539plusmn4197(62)

Album

in(gdL)

29439plusmn026

435plusmn020(minus09)

445plusmn032(13)

25438plusmn016

428plusmn019(minus23)lowast

432plusmn019(minus14

)Serum

creatin

ine(mgdL

)31

090

[083ndash10

0]090

[080ndash

100]

080

[080ndash

098]lowast

28090

[080ndash

095]

090

[080ndash

090]

080

[080ndash

090]lowast

Urin

arycreatin

ine(mgdL

)309447plusmn534811163plusmn7663(182)8340plusmn6143(minus117)

239535plusmn3922

10461plusmn5790(97)8274plusmn5170(minus132)

Urea(

mgdL

)32

1147plusmn292

1163plusmn372(14)

1084plusmn284(minus54)

271063plusmn278

1007plusmn216(minus52)

989plusmn219(minus70

)eG

FRb(m

Lmin

per173m

2 )287770plusmn1600

8061plusmn1226(37)8259plusmn1175(63)lowast

278242plusmn1353

8516plusmn1364(33)

8993plusmn1365(91)lowast

AST

c(IUL)

312323plusmn492

2339plusmn472(07)

2236plusmn462(minus38)

272178plusmn536

2193plusmn498(07)

2256plusmn503(36)

ALT

d(IUL)

291800plusmn6721566plusmn369(minus130)lowast1621plusmn502(minus100)lowast

261739plusmn673

1619plusmn467(minus69)

1627plusmn534(minus64)

TASe

(mmolL)

29148plusmn011

166plusmn011(119

)lowast177plusmn009(19

6)lowast

24148plusmn011

160plusmn008(83)lowast

179plusmn015(211)lowast

Hum

ansera

HT5

0(m

inutes)

311600plusmn323

1682plusmn323(51)lowast

1657plusmn324(36)lowast

261601plusmn335

1586plusmn261(minus09)

1597plusmn307(minus02)

Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereas

nonp

aram

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangerela

tivetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

8 BioMed Research International

0100020003000400050006000700080009000

Mea

n ca

lorie

inde

xda

y (a

u)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

Figure 2 Daily mean calorie index variation for participants undergreen tea and water regimen during the 14-week interventionperiod and 2-week washout period in a male and female MauritianpopulationMain and error bars representmean values and standarddeviations respectively for experimental group (male 119899 = 33female 119899 = 32) and control group (male 119899 = 30 female 119899 = 28)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

0

100

200

300

400

500

600

Lipi

dfa

t rat

iod

ay (a

u)

Figure 3 Daily lipidfat ratio for participants under green teaand water regimen during the 14-week intervention period and 2-week washout period in a male and female Mauritian populationMain and error bars represent mean values and standard deviationsrespectively for experimental group (male 119899 = 33 female 119899 = 32)and control group (male 119899 = 30 female 119899 = 28)

14 followed by a critical increase of 38 (119875 lt 01) (relativeto week 14 value) after the washout period

The ALT a transaminase enzyme used to determineliver health decreased significantly by 130 (119875 lt 01) asillustrated by the female experimental group on week 14whereas female control group did not show any significantchange throughout the clinical trial The time taken forhuman sera to delay hemolysis by 50 representing theantioxidant potential of human sera at the cellular levelincreased significantly by 27 (119875 lt 01) and 51 (119875 lt 01) inmale and female experimental groups respectively afterweek14 whereas their corresponding control groups experienceda decrease

0

100

200

300

400

500

Control 025 050 100 150Tim

e tak

en fo

r 50

hem

olys

is to

occ

ur

HT5

0 (m

inut

es)

lowastlowastlowast

lowastlowastlowast

lowastlowastlowast

Green tea extracts (mgmL)

Figure 4 The prophylactic effect of green tea extracts against freeradical which might be a causative agent of metabolic syndromeMain and error bars represent mean value and standard deviationof three independent experiments respectively Statistical analyseswere performed using independent samples 119905-test for multiplecomparisons lowastlowastlowastTime taken for 50 hemolysis to occur wassignificantly different from that of control (119875 lt 001)

4 Discussion

The current management of type 2 diabetes involves acombination of dietary plans exercise programs and the useof drugs such as sulfonylureas and biguanide [34] Besidesthese conventional therapies a growing body of evidencehas indicated the role of green tea polyphenols in improvingfeatures of metabolic syndrome and subsequent risks fordiabetes and its complications [1 35] The putative beneficialeffects ascribed to green tea polyphenols are partly mediatedby their free radical scavenging antioxidant action and abil-ity to form complexes withmetal ionsThe green tea analysedin this study had high levels of total phenols flavonoids andproanthocyanidins with a wide range individual compoundsthat synergistically contributed to the antioxidative propen-sity of the extract as evidenced by the multiantioxidant anal-ysis data including the free radical-induced hemolysis assaydata (Figure 4) Similar observations were made in an earlierreport where green and black teas were characterised for theirantioxidant functions [36] The green tea supplementation inthis study led to a significant increase in serum antioxidantcapacity as measured by the free radical-induced hemolysisassay This suggests that the oxidative stress condition thatcan be encountered in diabetes [3 4] could benefit fromgreen tea consumption Raza and John [37] have reportedthat tea catechins can prevent protein degradation by alteringsubcellular reactive oxygen species production glutathionemetabolism and cytochrome P450 2E1 activity Grinberget al [38] found that tea polyphenols protect red blood cellsagainst primaquine-induced lysis and H

2O2-induced lipid

peroxidation While it can be further derived from the datain this study that green tea consumption can reinforce invivo antioxidant defences the potential prophylactic effectsof green tea against diabetes and its complications remain tobe clearly defined In the study the effect of cigarette smokingexcessive alcohol intake and hormone replacement therapyon levels of biomarkers measured were minimised by theexclusion criteria applied to the subject population Dietary

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

6 BioMed Research International

Table3Ch

aracteris

ticso

fmalep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Maleg

reen

teag

roup

Malec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

33489plusmn69

30481plusmn79

Weight(kg)

33708plusmn136

716plusmn135

714plusmn138

30753plusmn133

759plusmn136

754plusmn134

BMI(kgm

2 )332467plusmn369

2497plusmn370(12)lowast

2487plusmn378(08)lowast

302628plusmn476

2646plusmn479(07)lowast

2623plusmn471(minus02)

Waist-

hipratio

33091plusmn006

090plusmn006(minus08)

089plusmn005(minus18

)lowast30

092plusmn005

091plusmn006(minus08)

090plusmn004(minus17

)lowastMAPa

(mmHg)

339349plusmn948

9285plusmn906(minus07)

9267plusmn1059(minus09)

299562plusmn870

9276plusmn873(minus30)lowast9229plusmn888(minus35)lowast

Glucose

(mgdL

)308970plusmn1118

9047plusmn1165(09)

9287plusmn945(35)

279056plusmn10358756plusmn1166(minus33)

8915plusmn1118(minus16

)HbA

1c(

)30

600[570ndash6

20]

590[570minus620]

605[580ndash6

30]lowast

28600[570ndash6

20]

590[560ndash6

10]lowast

595[570ndash6

10]

Cholesterol(mgdL

)3221875plusmn403919591plusmn3452(minus104)lowast19919plusmn3272(minus89)lowast

2921545plusmn400118486plusmn3534(minus142)lowast19410plusmn4206(minus99

)lowastTriglycerid

es(m

gdL

)3112542plusmn549712777plusmn5566(19)11555plusmn4838(minus79

)2612496plusmn477111558plusmn4115(minus75

)10804plusmn3881(minus135)lowast

LDL(m

gdL

)3214528plusmn337213147plusmn2853(minus95

)lowast13494plusmn2689(minus71)

2714789plusmn373412826plusmn2697(minus133)lowast13644plusmn3599(minus77

)HDL(m

gdL

)314858plusmn10924281plusmn1105(minus119)lowast4400plusmn1031(minus94

)lowast284554plusmn9413889plusmn830(minus146)lowast4086plusmn926(minus103)lowast

LDLHDL

31311plusmn085

322plusmn075(35)

322plusmn077(35)

26338plusmn103

329plusmn062(minus27)

341plusmn076(09)

Ferritin(ngdL

)2910045plusmn72689741plusmn6548(minus30)

9897plusmn6549(minus15

)268004plusmn471211142plusmn7586(392

)lowast10765plusmn7283(345)lowast

Album

in(gdL)

29450plusmn023

443plusmn020(minus14

)448plusmn020(minus05)

27450plusmn023

441plusmn023(minus21)lowast

447plusmn020(minus08)

Serum

creatin

ine(mgdL

)31

110[10

0ndash12

0]110[110ndash

120]

110[10

0ndash12

0]27

110[110ndash

120]

110[10

0ndash12

0]110[10

0ndash12

0]Urin

arycreatin

ine(mgdL

)2913152plusmn657618817plusmn9465(431)lowast17066plusmn7681(298

)lowast2913831plusmn701720038plusmn6494(449)lowast19738plusmn8027(427)lowast

Urea(

mgdL

)311442plusmn466

1465plusmn389(16)

1548plusmn394(74)

271363plusmn262

1385plusmn359(16)

1252plusmn264(minus82)lowast

eGFR

b(m

Lmin

per173m

2 )298262plusmn1673

7674plusmn900(minus71)lowast

7964plusmn1126(minus36)

278192plusmn1424

8424plusmn1379(28)

8555plusmn1535(44)

AST

c(IUL)

292635plusmn622

2641plusmn511(03)

2679plusmn554(17)

282711plusmn737

2693plusmn735(minus07)

2711plusmn721(00)

ALT

d(IUL)

322909plusmn16642706plusmn1345(minus70

)2781plusmn1139(minus44)

282825plusmn12992754plusmn1133(minus25)

2861plusmn1225(13)

TASe

(mmolL)

29160plusmn015

175plusmn011(95)lowast

192plusmn014(201)lowast

28162plusmn013

172plusmn010(62)lowast

192plusmn017(186)lowast

Hum

ansera

HT5

0(m

inutes)

281655plusmn257

1700plusmn272(27)lowast

1734plusmn265(48)lowast

281814plusmn313

1761plusmn255(minus29)

1780plusmn291(minus19

)Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereasno

nparam

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangesrelativetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

BioMed Research International 7

Table4Ch

aracteris

ticso

ffem

alep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Femaleg

reen

teag

roup

Femalec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

32493plusmn66

28469plusmn84

Weight(kg)

32613plusmn122

619plusmn124

617plusmn124

28632plusmn98

636plusmn98

637plusmn99

BMI(kgm

2 )31

2502plusmn366

2517plusmn359(06)

2507plusmn353(02)

282664plusmn329

2668plusmn334(01)

2674plusmn335(04)

Waist-

hipratio

31082plusmn005

082plusmn006(00)

084plusmn006(20)lowast

27083plusmn005

084plusmn005(18)lowast

085plusmn003(24)lowast

MAPa

(mmHg)

318880plusmn663

8774plusmn915(minus12

)8859plusmn916(minus02)

278894plusmn844

8663plusmn758(minus26)lowast

8685plusmn696(minus24)

Glucose

(mgdL

)329441plusmn1210

9484plusmn1347(05)9269plusmn1066(minus18

)28

9150plusmn970

9521plusmn1062(41)lowast

9121plusmn1169(minus03)

HbA

1c(

)30

610[590ndash6

50]

595

[580ndash

630]

610

[590ndash

640

]25

600

[578ndash610]

590

[580ndash

620]

600

[588ndash630]lowast

Cholesterol(mgdL

)3120987plusmn318119977plusmn3479(minus48)20813plusmn3711(minus08)

2820532plusmn475218879plusmn4214(minus81)lowast19404plusmn3234(minus55)lowast

Triglycerid

es(m

gdL

)3111855plusmn507311090plusmn5129(minus64)12490plusmn7412(54)

259368plusmn3353

10208plusmn3540(90)10316plusmn4548(101)

LDL(m

gdL

)3014040plusmn256812933plusmn2551(minus79

)lowast13830plusmn3003(minus15

)2713522plusmn385511663plusmn3705(minus137)lowast12882plusmn2620(minus47)

HDL(m

gdL

)315036plusmn10244842plusmn890(minus38)lowast4955plusmn920(minus16

)285207plusmn15294936plusmn1369(minus52)lowast4914plusmn1236(minus56)lowast

LDLHDL

29292plusmn083

276plusmn066(minus55)

290plusmn081(minus07)

27284plusmn125

251plusmn085(minus116)

275plusmn077(minus32)

Ferritin(ngdL

)294403plusmn36954917plusmn3675(117

)5055plusmn4501(14

8)

264273plusmn4205

4004plusmn3560(minus63)

4539plusmn4197(62)

Album

in(gdL)

29439plusmn026

435plusmn020(minus09)

445plusmn032(13)

25438plusmn016

428plusmn019(minus23)lowast

432plusmn019(minus14

)Serum

creatin

ine(mgdL

)31

090

[083ndash10

0]090

[080ndash

100]

080

[080ndash

098]lowast

28090

[080ndash

095]

090

[080ndash

090]

080

[080ndash

090]lowast

Urin

arycreatin

ine(mgdL

)309447plusmn534811163plusmn7663(182)8340plusmn6143(minus117)

239535plusmn3922

10461plusmn5790(97)8274plusmn5170(minus132)

Urea(

mgdL

)32

1147plusmn292

1163plusmn372(14)

1084plusmn284(minus54)

271063plusmn278

1007plusmn216(minus52)

989plusmn219(minus70

)eG

FRb(m

Lmin

per173m

2 )287770plusmn1600

8061plusmn1226(37)8259plusmn1175(63)lowast

278242plusmn1353

8516plusmn1364(33)

8993plusmn1365(91)lowast

AST

c(IUL)

312323plusmn492

2339plusmn472(07)

2236plusmn462(minus38)

272178plusmn536

2193plusmn498(07)

2256plusmn503(36)

ALT

d(IUL)

291800plusmn6721566plusmn369(minus130)lowast1621plusmn502(minus100)lowast

261739plusmn673

1619plusmn467(minus69)

1627plusmn534(minus64)

TASe

(mmolL)

29148plusmn011

166plusmn011(119

)lowast177plusmn009(19

6)lowast

24148plusmn011

160plusmn008(83)lowast

179plusmn015(211)lowast

Hum

ansera

HT5

0(m

inutes)

311600plusmn323

1682plusmn323(51)lowast

1657plusmn324(36)lowast

261601plusmn335

1586plusmn261(minus09)

1597plusmn307(minus02)

Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereas

nonp

aram

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangerela

tivetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

8 BioMed Research International

0100020003000400050006000700080009000

Mea

n ca

lorie

inde

xda

y (a

u)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

Figure 2 Daily mean calorie index variation for participants undergreen tea and water regimen during the 14-week interventionperiod and 2-week washout period in a male and female MauritianpopulationMain and error bars representmean values and standarddeviations respectively for experimental group (male 119899 = 33female 119899 = 32) and control group (male 119899 = 30 female 119899 = 28)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

0

100

200

300

400

500

600

Lipi

dfa

t rat

iod

ay (a

u)

Figure 3 Daily lipidfat ratio for participants under green teaand water regimen during the 14-week intervention period and 2-week washout period in a male and female Mauritian populationMain and error bars represent mean values and standard deviationsrespectively for experimental group (male 119899 = 33 female 119899 = 32)and control group (male 119899 = 30 female 119899 = 28)

14 followed by a critical increase of 38 (119875 lt 01) (relativeto week 14 value) after the washout period

The ALT a transaminase enzyme used to determineliver health decreased significantly by 130 (119875 lt 01) asillustrated by the female experimental group on week 14whereas female control group did not show any significantchange throughout the clinical trial The time taken forhuman sera to delay hemolysis by 50 representing theantioxidant potential of human sera at the cellular levelincreased significantly by 27 (119875 lt 01) and 51 (119875 lt 01) inmale and female experimental groups respectively afterweek14 whereas their corresponding control groups experienceda decrease

0

100

200

300

400

500

Control 025 050 100 150Tim

e tak

en fo

r 50

hem

olys

is to

occ

ur

HT5

0 (m

inut

es)

lowastlowastlowast

lowastlowastlowast

lowastlowastlowast

Green tea extracts (mgmL)

Figure 4 The prophylactic effect of green tea extracts against freeradical which might be a causative agent of metabolic syndromeMain and error bars represent mean value and standard deviationof three independent experiments respectively Statistical analyseswere performed using independent samples 119905-test for multiplecomparisons lowastlowastlowastTime taken for 50 hemolysis to occur wassignificantly different from that of control (119875 lt 001)

4 Discussion

The current management of type 2 diabetes involves acombination of dietary plans exercise programs and the useof drugs such as sulfonylureas and biguanide [34] Besidesthese conventional therapies a growing body of evidencehas indicated the role of green tea polyphenols in improvingfeatures of metabolic syndrome and subsequent risks fordiabetes and its complications [1 35] The putative beneficialeffects ascribed to green tea polyphenols are partly mediatedby their free radical scavenging antioxidant action and abil-ity to form complexes withmetal ionsThe green tea analysedin this study had high levels of total phenols flavonoids andproanthocyanidins with a wide range individual compoundsthat synergistically contributed to the antioxidative propen-sity of the extract as evidenced by the multiantioxidant anal-ysis data including the free radical-induced hemolysis assaydata (Figure 4) Similar observations were made in an earlierreport where green and black teas were characterised for theirantioxidant functions [36] The green tea supplementation inthis study led to a significant increase in serum antioxidantcapacity as measured by the free radical-induced hemolysisassay This suggests that the oxidative stress condition thatcan be encountered in diabetes [3 4] could benefit fromgreen tea consumption Raza and John [37] have reportedthat tea catechins can prevent protein degradation by alteringsubcellular reactive oxygen species production glutathionemetabolism and cytochrome P450 2E1 activity Grinberget al [38] found that tea polyphenols protect red blood cellsagainst primaquine-induced lysis and H

2O2-induced lipid

peroxidation While it can be further derived from the datain this study that green tea consumption can reinforce invivo antioxidant defences the potential prophylactic effectsof green tea against diabetes and its complications remain tobe clearly defined In the study the effect of cigarette smokingexcessive alcohol intake and hormone replacement therapyon levels of biomarkers measured were minimised by theexclusion criteria applied to the subject population Dietary

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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EndocrinologyInternational Journal of

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Disease Markers

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OncologyJournal of

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Oxidative Medicine and Cellular Longevity

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

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Research and TreatmentAIDS

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Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

BioMed Research International 7

Table4Ch

aracteris

ticso

ffem

alep

articipants(119899)atb

aselineaft

er14-w

eekinterventio

nperio

dandaft

er2-weekwasho

utperio

d

Varia

bles

Femaleg

reen

teag

roup

Femalec

ontro

lgroup

nBa

selin

eWeek14

Washo

utn

Baselin

eWeek14

Washo

utAge

(year)

32493plusmn66

28469plusmn84

Weight(kg)

32613plusmn122

619plusmn124

617plusmn124

28632plusmn98

636plusmn98

637plusmn99

BMI(kgm

2 )31

2502plusmn366

2517plusmn359(06)

2507plusmn353(02)

282664plusmn329

2668plusmn334(01)

2674plusmn335(04)

Waist-

hipratio

31082plusmn005

082plusmn006(00)

084plusmn006(20)lowast

27083plusmn005

084plusmn005(18)lowast

085plusmn003(24)lowast

MAPa

(mmHg)

318880plusmn663

8774plusmn915(minus12

)8859plusmn916(minus02)

278894plusmn844

8663plusmn758(minus26)lowast

8685plusmn696(minus24)

Glucose

(mgdL

)329441plusmn1210

9484plusmn1347(05)9269plusmn1066(minus18

)28

9150plusmn970

9521plusmn1062(41)lowast

9121plusmn1169(minus03)

HbA

1c(

)30

610[590ndash6

50]

595

[580ndash

630]

610

[590ndash

640

]25

600

[578ndash610]

590

[580ndash

620]

600

[588ndash630]lowast

Cholesterol(mgdL

)3120987plusmn318119977plusmn3479(minus48)20813plusmn3711(minus08)

2820532plusmn475218879plusmn4214(minus81)lowast19404plusmn3234(minus55)lowast

Triglycerid

es(m

gdL

)3111855plusmn507311090plusmn5129(minus64)12490plusmn7412(54)

259368plusmn3353

10208plusmn3540(90)10316plusmn4548(101)

LDL(m

gdL

)3014040plusmn256812933plusmn2551(minus79

)lowast13830plusmn3003(minus15

)2713522plusmn385511663plusmn3705(minus137)lowast12882plusmn2620(minus47)

HDL(m

gdL

)315036plusmn10244842plusmn890(minus38)lowast4955plusmn920(minus16

)285207plusmn15294936plusmn1369(minus52)lowast4914plusmn1236(minus56)lowast

LDLHDL

29292plusmn083

276plusmn066(minus55)

290plusmn081(minus07)

27284plusmn125

251plusmn085(minus116)

275plusmn077(minus32)

Ferritin(ngdL

)294403plusmn36954917plusmn3675(117

)5055plusmn4501(14

8)

264273plusmn4205

4004plusmn3560(minus63)

4539plusmn4197(62)

Album

in(gdL)

29439plusmn026

435plusmn020(minus09)

445plusmn032(13)

25438plusmn016

428plusmn019(minus23)lowast

432plusmn019(minus14

)Serum

creatin

ine(mgdL

)31

090

[083ndash10

0]090

[080ndash

100]

080

[080ndash

098]lowast

28090

[080ndash

095]

090

[080ndash

090]

080

[080ndash

090]lowast

Urin

arycreatin

ine(mgdL

)309447plusmn534811163plusmn7663(182)8340plusmn6143(minus117)

239535plusmn3922

10461plusmn5790(97)8274plusmn5170(minus132)

Urea(

mgdL

)32

1147plusmn292

1163plusmn372(14)

1084plusmn284(minus54)

271063plusmn278

1007plusmn216(minus52)

989plusmn219(minus70

)eG

FRb(m

Lmin

per173m

2 )287770plusmn1600

8061plusmn1226(37)8259plusmn1175(63)lowast

278242plusmn1353

8516plusmn1364(33)

8993plusmn1365(91)lowast

AST

c(IUL)

312323plusmn492

2339plusmn472(07)

2236plusmn462(minus38)

272178plusmn536

2193plusmn498(07)

2256plusmn503(36)

ALT

d(IUL)

291800plusmn6721566plusmn369(minus130)lowast1621plusmn502(minus100)lowast

261739plusmn673

1619plusmn467(minus69)

1627plusmn534(minus64)

TASe

(mmolL)

29148plusmn011

166plusmn011(119

)lowast177plusmn009(19

6)lowast

24148plusmn011

160plusmn008(83)lowast

179plusmn015(211)lowast

Hum

ansera

HT5

0(m

inutes)

311600plusmn323

1682plusmn323(51)lowast

1657plusmn324(36)lowast

261601plusmn335

1586plusmn261(minus09)

1597plusmn307(minus02)

Parametric

varia

blesaree

xpressed

asmeanplusmnstandard

deviationwhereas

nonp

aram

etric

varia

blesaree

xpressed

asmedian[in

terquartile

range]Percentagec

hangerela

tivetobaselin

emeans

areind

icated

inroun

dbracketslowastMeanor

medianvalueissig

nificantly

different

from

thatof

baselin

e(119875lt01)(compare

with

inrowandwith

ingrou

p)Meanor

medianvalueissig

nificantly

different

from

thatof

week14

(119875lt01)

(com

pare

with

inrowandbetweengrou

p)aMeanarteria

lpressure

b estimated

glom

erular

filtrationratecam

inotransferase

aspartate

d aminotransferase

alanine

e totalantio

xidant

status

8 BioMed Research International

0100020003000400050006000700080009000

Mea

n ca

lorie

inde

xda

y (a

u)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

Figure 2 Daily mean calorie index variation for participants undergreen tea and water regimen during the 14-week interventionperiod and 2-week washout period in a male and female MauritianpopulationMain and error bars representmean values and standarddeviations respectively for experimental group (male 119899 = 33female 119899 = 32) and control group (male 119899 = 30 female 119899 = 28)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

0

100

200

300

400

500

600

Lipi

dfa

t rat

iod

ay (a

u)

Figure 3 Daily lipidfat ratio for participants under green teaand water regimen during the 14-week intervention period and 2-week washout period in a male and female Mauritian populationMain and error bars represent mean values and standard deviationsrespectively for experimental group (male 119899 = 33 female 119899 = 32)and control group (male 119899 = 30 female 119899 = 28)

14 followed by a critical increase of 38 (119875 lt 01) (relativeto week 14 value) after the washout period

The ALT a transaminase enzyme used to determineliver health decreased significantly by 130 (119875 lt 01) asillustrated by the female experimental group on week 14whereas female control group did not show any significantchange throughout the clinical trial The time taken forhuman sera to delay hemolysis by 50 representing theantioxidant potential of human sera at the cellular levelincreased significantly by 27 (119875 lt 01) and 51 (119875 lt 01) inmale and female experimental groups respectively afterweek14 whereas their corresponding control groups experienceda decrease

0

100

200

300

400

500

Control 025 050 100 150Tim

e tak

en fo

r 50

hem

olys

is to

occ

ur

HT5

0 (m

inut

es)

lowastlowastlowast

lowastlowastlowast

lowastlowastlowast

Green tea extracts (mgmL)

Figure 4 The prophylactic effect of green tea extracts against freeradical which might be a causative agent of metabolic syndromeMain and error bars represent mean value and standard deviationof three independent experiments respectively Statistical analyseswere performed using independent samples 119905-test for multiplecomparisons lowastlowastlowastTime taken for 50 hemolysis to occur wassignificantly different from that of control (119875 lt 001)

4 Discussion

The current management of type 2 diabetes involves acombination of dietary plans exercise programs and the useof drugs such as sulfonylureas and biguanide [34] Besidesthese conventional therapies a growing body of evidencehas indicated the role of green tea polyphenols in improvingfeatures of metabolic syndrome and subsequent risks fordiabetes and its complications [1 35] The putative beneficialeffects ascribed to green tea polyphenols are partly mediatedby their free radical scavenging antioxidant action and abil-ity to form complexes withmetal ionsThe green tea analysedin this study had high levels of total phenols flavonoids andproanthocyanidins with a wide range individual compoundsthat synergistically contributed to the antioxidative propen-sity of the extract as evidenced by the multiantioxidant anal-ysis data including the free radical-induced hemolysis assaydata (Figure 4) Similar observations were made in an earlierreport where green and black teas were characterised for theirantioxidant functions [36] The green tea supplementation inthis study led to a significant increase in serum antioxidantcapacity as measured by the free radical-induced hemolysisassay This suggests that the oxidative stress condition thatcan be encountered in diabetes [3 4] could benefit fromgreen tea consumption Raza and John [37] have reportedthat tea catechins can prevent protein degradation by alteringsubcellular reactive oxygen species production glutathionemetabolism and cytochrome P450 2E1 activity Grinberget al [38] found that tea polyphenols protect red blood cellsagainst primaquine-induced lysis and H

2O2-induced lipid

peroxidation While it can be further derived from the datain this study that green tea consumption can reinforce invivo antioxidant defences the potential prophylactic effectsof green tea against diabetes and its complications remain tobe clearly defined In the study the effect of cigarette smokingexcessive alcohol intake and hormone replacement therapyon levels of biomarkers measured were minimised by theexclusion criteria applied to the subject population Dietary

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

8 BioMed Research International

0100020003000400050006000700080009000

Mea

n ca

lorie

inde

xda

y (a

u)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

Figure 2 Daily mean calorie index variation for participants undergreen tea and water regimen during the 14-week interventionperiod and 2-week washout period in a male and female MauritianpopulationMain and error bars representmean values and standarddeviations respectively for experimental group (male 119899 = 33female 119899 = 32) and control group (male 119899 = 30 female 119899 = 28)

MaleMale Female FemaleGreen tea Control

During 2-week washout period During 14-week intervention period

0

100

200

300

400

500

600

Lipi

dfa

t rat

iod

ay (a

u)

Figure 3 Daily lipidfat ratio for participants under green teaand water regimen during the 14-week intervention period and 2-week washout period in a male and female Mauritian populationMain and error bars represent mean values and standard deviationsrespectively for experimental group (male 119899 = 33 female 119899 = 32)and control group (male 119899 = 30 female 119899 = 28)

14 followed by a critical increase of 38 (119875 lt 01) (relativeto week 14 value) after the washout period

The ALT a transaminase enzyme used to determineliver health decreased significantly by 130 (119875 lt 01) asillustrated by the female experimental group on week 14whereas female control group did not show any significantchange throughout the clinical trial The time taken forhuman sera to delay hemolysis by 50 representing theantioxidant potential of human sera at the cellular levelincreased significantly by 27 (119875 lt 01) and 51 (119875 lt 01) inmale and female experimental groups respectively afterweek14 whereas their corresponding control groups experienceda decrease

0

100

200

300

400

500

Control 025 050 100 150Tim

e tak

en fo

r 50

hem

olys

is to

occ

ur

HT5

0 (m

inut

es)

lowastlowastlowast

lowastlowastlowast

lowastlowastlowast

Green tea extracts (mgmL)

Figure 4 The prophylactic effect of green tea extracts against freeradical which might be a causative agent of metabolic syndromeMain and error bars represent mean value and standard deviationof three independent experiments respectively Statistical analyseswere performed using independent samples 119905-test for multiplecomparisons lowastlowastlowastTime taken for 50 hemolysis to occur wassignificantly different from that of control (119875 lt 001)

4 Discussion

The current management of type 2 diabetes involves acombination of dietary plans exercise programs and the useof drugs such as sulfonylureas and biguanide [34] Besidesthese conventional therapies a growing body of evidencehas indicated the role of green tea polyphenols in improvingfeatures of metabolic syndrome and subsequent risks fordiabetes and its complications [1 35] The putative beneficialeffects ascribed to green tea polyphenols are partly mediatedby their free radical scavenging antioxidant action and abil-ity to form complexes withmetal ionsThe green tea analysedin this study had high levels of total phenols flavonoids andproanthocyanidins with a wide range individual compoundsthat synergistically contributed to the antioxidative propen-sity of the extract as evidenced by the multiantioxidant anal-ysis data including the free radical-induced hemolysis assaydata (Figure 4) Similar observations were made in an earlierreport where green and black teas were characterised for theirantioxidant functions [36] The green tea supplementation inthis study led to a significant increase in serum antioxidantcapacity as measured by the free radical-induced hemolysisassay This suggests that the oxidative stress condition thatcan be encountered in diabetes [3 4] could benefit fromgreen tea consumption Raza and John [37] have reportedthat tea catechins can prevent protein degradation by alteringsubcellular reactive oxygen species production glutathionemetabolism and cytochrome P450 2E1 activity Grinberget al [38] found that tea polyphenols protect red blood cellsagainst primaquine-induced lysis and H

2O2-induced lipid

peroxidation While it can be further derived from the datain this study that green tea consumption can reinforce invivo antioxidant defences the potential prophylactic effectsof green tea against diabetes and its complications remain tobe clearly defined In the study the effect of cigarette smokingexcessive alcohol intake and hormone replacement therapyon levels of biomarkers measured were minimised by theexclusion criteria applied to the subject population Dietary

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

BioMed Research International 9

survey questionnaires indicated that daily mean calorie indexand daily lipidfat ratio of the population diet did not changesignificantly during the 16-week period The subjects alsowere not on any medication against diabetes cardiovasculardiseases or hypertensionThus it is not plausible at this stageto suggest whether the effects of green tea regimen could betranslated to other dietary factors and medication

Anthropometric data suggest that green tea regimen fora 14-week intervention period suppressed the significantelevation of waist-hip ratio in the female experimental groupIt is of interest to note that in a randomized double-blindplacebo-controlled clinical trial obese women supplementedwith green tea for a 12-week intervention period experienceda marked reduction in waist and hip circumference [39]The mechanism by which tea or its bioactive componentsmight decrease abdominal obesity may occur at differentlevels In the digestive tract green tea catechins appear toform complexes with lipids and lipolytic enzymes therebyinterfering with the luminal processes of emulsificationhydrolysis micellar solubilisation and subsequent uptake oflipids [40] An increase in 24-hour energy expenditure andfat oxidation in humans has also been attributed to green teaconsumption [41]

The consumption of green tea 3 times a day suppressedmean arterial pressure from a significant decrease after week14 indicating that green tea may promote a good bloodflow all around the body and as a consequence preventsischemic reperfusion injury of end organs Potenza et al[42] investigated the metabolic effects of epigallocatechin-3-gallate (EGCG) in spontaneously hypertensive rats EGCG(200mgkg for 3 weeks) significantly reduced systolic bloodpressure and enhanced both endothelial function and insulinsensitivity It has also been shown that epicatechin derivativesfrom green tea leaves can relax rat mesenteric arteriesprobably by inhibiting Ca2+ influx and increasing nitric oxiderelease which has a vasodilatory effect [43 44]

Green tea consumption during the 14-week period ofstudy did not affect fasting plasma glucose (measured usingthe glucose oxidase method) nor was the level of theH1Ac impacted The green tea regimen however preventedimpaired fasting glucose from a significant increase as com-pared to the control groupThese findings show the potentialrole of green tea as a glycemic regulatorThe subjects involvedin this study are prediabetic who have the potential riskfor developing diabetes Li et al [45] postulated that greentea catechins might ameliorate insulin resistance by actingas peroxisome proliferator-activated receptor ligands with adual alphagamma agonistic effect Green tea phytochemicalsare also reported to prevent intestinal glucose uptake byinhibiting the sodium-dependent glucose transporter of rab-bit intestinal epithelial cells [46] Many other interventionalclinical trials have also illustrated the beneficial effect of greentea against diabetes [47ndash49]

Ferritin a ubiquitous intracellular protein stores iron andreleases it in a controlled fashion The amount of ferritinusually reflects the amount of iron in vivo Iron a redox activetransition metal ion is important for the normal functioningof the human body However at high level free ferrousions react with peroxides to produce hydroxyl radicals

via the Fenton reaction The formed hydroxyl radicals arehighly reactive and can damage cellular components suchas proteins DNA and lipids At week 14 of the green tearegimen the ferritin of male experimental group slightlyreduced whereas the ferritin of male control group increasedconsiderably by 392 (119875 lt 01) A plausible explanationfor our results is that iron-phenol chelates might form inthe lumen during digestion resulting in lower iron absorp-tion [50] Interestingly Kim et al [51] also showed thatepigallocatechin-3-gallate inhibit nonheme iron absorptionby reducing basolateral iron exit possibly through formationof a nontransportable polyphenol-iron complex

Daily consumption of green tea has been often associatedwith a lifestyle which may support healthiness and longevityHowever the hepatotoxicity of green tea has been put intoquestion and led to the recent publication of a systematicreview of the safety of green tea extracts by the UnitedStates Pharmacopeia [52] In our study the consumptionof green tea three times a day before meals did not showany hepatotoxic effect Consistent with this outcome isthe interventional studies involving supplementation with714mg green tea polyphenol daily to healthy men for 3weeks and supplementation of 500mg green tea polyphenoldaily to postmenopausal osteopenic women for 24 weeks notcausing any adverse effects on liver and kidney function asdetermined by blood test parameters [53 54]

Chronic kidney disease is recognized public health prob-lem and eGFR has been considered to be a good indicatorto evaluate renal function Most clinicians claimed that itis difficult to estimate glomerular filtration rate only fromserum creatinine concentration as its accuracy is affected byother factors [55] To circumvent these limitations severalformulas have been designed to estimate glomerular filtrationrate not only from serum creatinine concentration but alsofrom age body size gender serum albumin concentrationand serum urea concentration [56] The 6-variable MDRDequation has been used eGFR of male experimental groupdecreased significantly on week 14 and after discontinuingthe green tea regimen for a 2-week washout period a criticalincrease of 38 (relative to week 14 value) in eGFR wasnoticed Current guidelines define chronic kidney disease asa glomerular filtration rate less than 60mLmin per 173m2for 3months ormore [57 58] On the contrary the findings inthis study showed that the green tea regimen decreased eGFRto a concentrationwhichwas still greater than the cutoff pointassociated with kidney damageThe clinical trial also showedthat the green tea regimen is not associated with any sideeffects or toxicity at the recommended level of intake andrevealed prophylactic effects such as antiobesity Relative towater regimen the green tea regimen prevents waist-hip ratioof subjects from a significant increase during the interventionperiod It significantly increases the antioxidant capacity ofserum

In conclusion the clinical trial is acknowledgeable tocertain limitations It was not possible for all subjects tomaintain their normal diet Their cooking mode and theamount of food consumed by each subject were not knownIn the future a more detailed dietary survey questionnaireshould be used to ensure that the prescribed regimen is

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

10 BioMed Research International

being properly followed The protocol for using 3 cups ofgreen tea was initially based on the total phenolic contentcorresponding to 235mg gallic acid equivalentcup thusbringing the ingestion to 705mg of total phenolsday Thiswas consistent with the literature data [53 54] and ourprevious studies using black tea [7 59] which have shownsignificant changes in cardiovascular disease clinical param-eters with 267mg of total phenolsday In the light of thedata obtained in this study a greater intervention periodand a consumption of more than 3 cups per day couldeventually be envisaged for a more significant modulation ofthe clinical markers Nonetheless more in-depth research iswarranted to corroborate these potential benefits in a largemultinational cohort [60] The green tea regimen could formpart of a healthy lifestyle that might ameliorate features ofmetabolic syndrome and subsequent risks for individualswith the potential propensity to develop type 2 diabetes Themechanisms accounting for the beneficial healthy effects ofgreen tea merit further exploration at the molecular level

Conflict of Interests

All authors read and approved the final paper None of theauthors had any conflict of interests

Acknowledgments

This work was supported by grants from the Universite dela Reunion La Reunion France (Conseil Regional de LaReunion et lrsquoEurope) University ofMauritiusMauritius Ter-tiary Education Commission Mauritius Mauritius ResearchCouncil Mauritius Societe Usiniere de St Aubin Mauritiusand the Conseil Regional de la Reunion et lrsquoEurope Thelogistics were supported by the Apollo Bramwell HospitalMauritius Biosante Ltd Mauritius Societe Usiniere de StAubin Mauritius and the Cardiac Centre of the Sir See-woosagur Ramgoolam National Hospital PamplemoussesMauritius Naushad Ali Toolsee was awarded a postgraduateresearch scholarship by the Tertiary Education Commissionof Mauritius This study was conducted under the NationalResearch Chair program (Theeshan Bahorun)

References

[1] S Wolfram ldquoEffects of green tea and EGCG on cardiovascularand metabolic healthrdquo Journal of the American College ofNutrition vol 26 no 4 pp 373Sndash388S 2007

[2] A P Robertson ldquoChronic oxidative stress as a central mech-anism for glucose toxicity in pancreatic islet beta cells indiabetesrdquo The Journal of Biological Chemistry vol 279 no 41pp 42351ndash42354 2004

[3] O I Aruoma V S Neergheen T Bahorun and L Jen ldquoFreeradicals antioxidants and diabetes embryopathy retinopathyneuropathy nephropathy and cardiovascular complicationsrdquoNeuroembryology and Aging vol 4 no 3 pp 117ndash137 2007

[4] H Kaneto N Katakami D Kawamori et al ldquoInvolvement ofoxidative stress in the pathogenesis of diabetesrdquo Antioxidantsand Redox Signaling vol 9 no 3 pp 355ndash366 2007

[5] I Rudkowska ldquoFunctional foods for health focus on diabetesrdquoMaturitas vol 62 no 3 pp 263ndash269 2009

[6] A Rietveld and S Wiseman ldquoAntioxidant effects of tea evi-dence from human clinical trialsrdquo Journal of Nutrition vol 133no 10 pp 3285Sndash3292S 2003

[7] T Bahorun A Luximon-Ramma V S Neergheen-Bhujun etal ldquoThe effect of black tea on risk factors of cardiovasculardisease in a normal populationrdquo Preventive Medicine vol 54Supplement 1 pp S98ndashS102 2012

[8] J A Vinson K Teufel and N Wu ldquoGreen and black teasinhibit atherosclerosis by lipid antioxidant and fibrinolyticmechanismsrdquo Journal of Agricultural and Food Chemistry vol52 no 11 pp 3661ndash3665 2004

[9] A Basu M Du K Sanchez et al ldquoGreen tea minimally affectsbiomarkers of inflammation in obese subjects with metabolicsyndromerdquo Nutrition vol 27 no 2 pp 206ndash213 2011

[10] C Cabrera R Artacho and R Gimenez ldquoBeneficial effectsof green teamdasha reviewrdquo Journal of the American College ofNutrition vol 25 no 2 pp 79ndash99 2006

[11] N C Cook and S Samman ldquoFlavonoidsmdashchemistrymetabolism cardioprotective effects and dietary sourcesrdquoJournal of Nutritional Biochemistry vol 7 no 2 pp 66ndash761996

[12] E Tedeschi M Menegazzi Y Yao H Suzuki U Forstermannand H Kleinert ldquoGreen tea inhibits human inducible nitric-oxide synthase expression by down-regulating signal trans-ducer and activator of transcription-1120572 activationrdquo MolecularPharmacology vol 65 no 1 pp 111ndash120 2004

[13] R A Anderson and M M Polansky ldquoTea enhances insulinactivityrdquo Journal of Agricultural and Food Chemistry vol 50 no24 pp 7182ndash7186 2002

[14] S Rhee M Kim and O Kwag ldquoEffects of green tea catechinon prostaglandin synthesis of renal glomerular and renal dys-function in streptozotocin-induced diabetic ratsrdquo Asia PacificJournal of Clinical Nutrition vol 11 no 3 pp 232ndash236 2002

[15] S Priyadarshi B Valentine C Han et al ldquoEffect of green teaextract on cardiac hypertrophy following 56 nephrectomy inthe ratrdquoKidney International vol 63 no 5 pp 1785ndash1790 2003

[16] N Yamabe T Yokozawa T Oya and M Kim ldquoTherapeuticpotential of (-)-epigallocatechin 3-O-gallate on renal damage indiabetic nephropathy model ratsrdquo Journal of Pharmacology andExperimental Therapeutics vol 319 no 1 pp 228ndash236 2006

[17] P D B Ribaldo D S Souza S K Biswas K Block J M L DeFaria and J B L De Faria ldquoGreen tea (Camellia sinensis) atten-uates nephropathy by downregulatingNox4NADPHoxidase indiabetic spontaneously hypertensive ratsrdquo Journal of Nutritionvol 139 no 1 pp 96ndash100 2009

[18] V L Singleton and J A Rossi ldquoColorimetry of total phenolicswith phosphomolybdic-phosphotungstic acid reagentsrdquoAmeri-can Journal of Enology and Viticulture vol 16 pp 144ndash158 1965

[19] J L Lamaison and A Carnet ldquoMain flavonoid levels in flowersand leaves ofCrataegus monogyna Jacq andCrataegus laevigataDC during the developmental stagerdquo Plantes Medicinales etPhytotherapie vol 25 no 1 pp 12ndash16 1991

[20] L J Porter L N Hrstich and B G Chan ldquoThe conversionof procyanidins and prodelphinidins to cyanidin and delphini-dinrdquo Phytochemistry vol 25 no 1 pp 223ndash230 1985

[21] H Wang K Helliwell and X You ldquoIsocratic elution systemfor the determination of catechins caffeine and gallic acid ingreen tea using HPLCrdquo Food Chemistry vol 68 no 1 pp 115ndash121 2000

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

BioMed Research International 11

[22] M Nishikimi N Appaji Rao and K Yagi ldquoThe occurrence ofsuperoxide anion in the reaction of reduced phenazine metho-sulfate and molecular oxygenrdquo Biochemical and BiophysicalResearch Communications vol 46 no 2 pp 849ndash854 1972

[23] D C Garratt The Quantitative Analysis of Drugs vol 3Chapman and Hall 1964

[24] C Henriquez C Aliaga and E Lissi ldquoFormation and decayof the ABTS derived radical cation a comparison of differ-ent preparation proceduresrdquo International Journal of ChemicalKinetics vol 34 no 12 pp 659ndash665 2002

[25] I F F Benzie and J J Strain ldquoThe ferric reducing ability ofplasma (FRAP) as a measure of rsquoantioxidant powerrsquo The FRAPassayrdquo Analytical Biochemistry vol 239 no 1 pp 70ndash76 1996

[26] O P Sharma andT K Bhat ldquoDPPHantioxidant assay revisitedrdquoFood Chemistry vol 113 no 4 pp 1202ndash1205 2009

[27] L L Stookey ldquoFerrozinemdasha new spectrophotometric reagentfor ironrdquo Analytical Chemistry vol 42 no 7 pp 779ndash781 1970

[28] L Wang M Bassiri R Najafi et al ldquoHypochlorous acid asa potential wound care agent part I stabilized hypochlorousacid a component of the inorganic armamentarium of innateimmunityrdquo Journal of Burns andWounds vol 6 pp 65ndash79 2007

[29] O I Aruoma and B Halliwell ldquoAction of hypochlorous acidon the antioxidant protective enzymes superoxide dismutasecatalase and glutathione peroxidaserdquo Biochemical Journal vol248 no 3 pp 973ndash976 1987

[30] M Prost ldquoProcess for the determination by means of freeradicals of the antioxidant properties of a living organism ora potentially aggressive agerdquo US patent application 51358501992

[31] United States Department of Agriculture and AgriculturalResearch Service ldquoUSDA National Nutrient Database for Stan-dard Reference Release 23rdquo Nutrient Data Laboratory HomePage httpwwwarsusdagovbabhnrcndl 2010

[32] A S Levey J P Bosch J B Lewis T Greene N Rogers and DRoth ldquoAmore accuratemethod to estimate glomerular filtrationrate from serum creatinine a new prediction equationrdquo Annalsof Internal Medicine vol 130 no 6 pp 461ndash470 1999

[33] C S Alisi and G O C Onyeze ldquoNitric oxide scavengingability of ethyl acetate fraction of methanolic leaf extracts ofChromolaena odorata (Linn)rdquo African Journal of BiochemistryResearch vol 2 no 7 pp 145ndash150 2008

[34] R JMahler andM LAdler ldquoClinical review 102 type 2 diabetesmellitus update on diagnosis pathophysiology and treatmentrdquoJournal of Clinical Endocrinology andMetabolism vol 84 no 4pp 1165ndash1171 1999

[35] F Thielecke and M Boschmann ldquoThe potential role of greentea catechins in the prevention of the metabolic syndromemdashareviewrdquo Phytochemistry vol 70 no 1 pp 11ndash24 2009

[36] A Luximon-Ramma V S Neergheen T Bahorun et alldquoAssessment of the polyphenolic composition of the organicextracts of Mauritian black teas a potential contributor to theirantioxidant functionsrdquo BioFactors vol 27 no 1ndash4 pp 79ndash912006

[37] H Raza and A John ldquoIn vitro protection of reactive oxy-gen species-induced degradation of lipids proteins and 2-deoxyribose by tea catechinsrdquo Food and Chemical Toxicologyvol 45 no 10 pp 1814ndash1820 2007

[38] L N Grinberg H Newmark N Kitrossky E RahamimM Chevion and E A Rachmilewitz ldquoProtective effects oftea polyphenols against oxidative damage to red blood cellsrdquoBiochemical Pharmacology vol 54 no 9 pp 973ndash978 1997

[39] C Hsu T Tsai Y Kao K Hwang T Tseng and P Chou ldquoEffectof green tea extract on obese women a randomized double-blind placebo-controlled clinical trialrdquo Clinical Nutrition vol27 no 3 pp 363ndash370 2008

[40] S I Koo and S K Noh ldquoGreen tea as inhibitor of the intestinalabsorption of lipids potential mechanism for its lipid-loweringeffectrdquo Journal of Nutritional Biochemistry vol 18 no 3 pp 179ndash183 2007

[41] A G Dulloo C Duret D Rohrer et al ldquoEfficacy of a green teaextract rich in catechin polyphenols and caffeine in increasing24-h energy expenditure and fat oxidation in humansrdquo Ameri-can Journal of Clinical Nutrition vol 70 no 6 pp 1040ndash10451999

[42] M A Potenza F L Marasciulo M Tarquinio et al ldquoEGCGa green tea polyphenol improves endothelial function andinsulin sensitivity reduces blood pressure and protects againstmyocardial IR injury in SHRrdquo American Journal of Physiologyvol 292 no 5 pp E1378ndashE1387 2007

[43] Y Huang A Zhang C Lau and Z Chen ldquoVasorelaxant effectsof purified green tea epicatechin derivatives in rat mesentericarteryrdquo Life Sciences vol 63 no 4 pp 275ndash283 1998

[44] Y Huang N W K Chan C W Lau X Q Yao F L Chanand Z Y Chen ldquoInvolvement of endotheliumnitric oxide invasorelaxation induced by purified green tea (-)epicatechinrdquoBiochimica et Biophysica Acta vol 1427 no 2 pp 322ndash328 1999

[45] R W Li T D Douglas G K Maiyoh K Adeli and A GTheriault ldquoGreen tea leaf extract improves lipid and glucosehomeostasis in a fructose-fed insulin-resistant hamster modelrdquoJournal of Ethnopharmacology vol 104 no 1-2 pp 24ndash31 2006

[46] Y Kobayashi M Suzuki H Satsu et al ldquoGreen tea polyphenolsinhibit the sodium-dependent glucose transporter of intestinalepithelial cells by a competitive mechanismrdquo Journal of Agricul-tural and Food Chemistry vol 48 no 11 pp 5618ndash5623 2000

[47] H Tsuneki M Ishizuka M Terasawa J Wu T Sasaoka and IKimura ldquoEffect of green tea on blood glucose levels and serumproteomic patterns in diabetic (dbdb) mice and on glucosemetabolism in healthy humansrdquo BMC Pharmacology vol 4article 18 2004

[48] Y Fukino M Shimbo N Aoki T Okubo and H Iso ldquoRan-domized controlled trial for an effect of green tea consumptionon insulin resistance and inflammation markersrdquo Journal ofNutritional Science and Vitaminology vol 51 no 5 pp 335ndash3422005

[49] K H Van het Hof H S M De Boer S A Wiseman N Lien JA Weststrate and L B M Tijburg ldquoConsumption of green orblack tea does not increase resistance of low-density lipoproteinto oxidation in humansrdquoAmerican Journal of Clinical Nutritionvol 66 no 5 pp 1125ndash1132 1997

[50] S Samman B Sandstrom M B Toft et al ldquoGreen teaor rosemary extract added to foods reduces nonheme-ironabsorptionrdquo American Journal of Clinical Nutrition vol 73 no3 pp 607ndash612 2001

[51] E Kim S Ham M K Shigenaga and O Han ldquoBioac-tive dietary polyphenolic compounds reduce nonheme irontransport across human intestinal cell monolayersrdquo Journal ofNutrition vol 138 no 9 pp 1647ndash1651 2008

[52] D N Sarma M L Barrett M L Chavez et al ldquoSafety of greentea extracts a systematic review by theUS PharmacopeiardquoDrugSafety vol 31 no 6 pp 469ndash484 2008

[53] J Frank T W George J K Lodge et al ldquoDaily consumptionof an aqueous green tea extract supplement does not impair

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

12 BioMed Research International

liver function or alter cardiovascular disease risk biomarkersin healthy menrdquo Journal of Nutrition vol 139 no 1 pp 58ndash622009

[54] C Shen M Chyu B C Pence et al ldquoGreen tea polyphenolssupplementation and Tai Chi exercise for postmenopausalosteopenic women safety and quality of life reportrdquo BMCComplementary and Alternative Medicine vol 10 article 762010

[55] R D Perrone N E Madias and A S Levey ldquoSerum creatinineas an index of renal function new insights into old conceptsrdquoClinical Chemistry vol 38 no 10 pp 1933ndash1953 1992

[56] G F Gates ldquoCreatinine clearance estimation from serumcreatinine values an analysis of three mathematical models ofglomerular functionrdquo American Journal of Kidney Diseases vol5 no 3 pp 199ndash205 1985

[57] A S Levey J Coresh E Balk et al ldquoNational KidneyFoundation Practice Guidelines for Chronic Kidney Diseaseevaluation classification and stratificationrdquo Annals of InternalMedicine vol 139 no 2 pp 137ndashI36 2003

[58] A S Levey K Eckardt Y Tsukamoto et al ldquoDefinition andclassification of chronic kidney disease a position statementfromKidney Disease improving Global Outcomes (KDIGO)zrdquoKidney International vol 67 no 6 pp 2089ndash2100 2005

[59] T Bahorun A Luximon-Ramma T K Gunness et al ldquoBlacktea reduces uric acid and C-reactive protein levels in humanssusceptible to cardiovascular diseasesrdquo Toxicology vol 278 no1 pp 68ndash74 2010

[60] S Soderberg P Zimmet J Tuomilehto et al ldquoIncreasingprevalence of Type 2 diabetes mellitus in all ethnic groups inMauritiusrdquo Diabetic Medicine vol 22 no 1 pp 61ndash68 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

MEDIATORSINFLAMMATION

of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Behavioural Neurology

EndocrinologyInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Disease Markers

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

BioMed Research International

OncologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Oxidative Medicine and Cellular Longevity

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Computational and Mathematical Methods in Medicine

OphthalmologyJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Diabetes ResearchJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Research and TreatmentAIDS

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Gastroenterology Research and Practice

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom