activit©s antioxydante et antimicrobienne d'extraits de rhamnus

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  • N0 ../SNV/2021

    Dpartement de Biochimie

    MEMOIRE

    Prsent par : HARRAR Abd El Nacer

    Pour obtenir le diplme de Magister

    Option : Biochimie et physiologie exprimentale

    THEME :

    Activits antioxydante et

    antimicrobienne dextraits de Rhamnus

    alaternus L.

    Soutenu publiquement le...//2012

    Devant le jury

    Prsident : Pr. Benboubetra Mustapha Pr. Universit de Stif

    Rapporteur : Dr. Belhattab Rachid Dr. Universit de Stif

    Examinateur : Pr. Laouar Hocine Pr. Universit de Stif

    Dr. Zerroug Mohamed Mihoub Dr. Universit de Stif

    Anne universitaire 2011-2012

  • DEDICACE

    Je ddie ce travail mes Parents quils trouvent ici toute ma

    gratitude

    Pour leur soutien tout le long de mes tudes

    A ma Sur et mes Frres

    mes Amis

    A ceux qui mont tout donn sans rien en retour

  • REMERCIEMENTS

    Je remercie DIEU tout puissant, matre des cieux et de la terre,

    qui ma permis de mener bien ce travail.

    Tout d'abord je tiens surtout adresser mes plus vifs

    remerciements mon promoteur Mr. Belhattab Rachid, Matre

    de confrences qui ma fait lhonneur de raliser ce travail sous

    sa direction, pour sa grande patience, pour sa disponibilit et

    ses conseils judicieux.

    Je remercie galement Mr Benboubetra Mustapha, Professeur

    la facult des Sciences de la Nature et de la Vie luniversit

    de Stif davoir accept de prsid le jury.

    Je remercie Mr Laouar Houcine, Professeur la facult des

    Sciences de la Nature et de la Vie luniversit de Stif davoir

    accept de juger ce modeste travail et participer au jury.

    Je remercie Mr Zerroug Mohamed Mihoub, Matre de confrences

    la facult des Sciences de la Nature et de la Vie luniversit

    de Stif, davoir accept dtre parmi les membres du jury de ce

    mmoire.

    Je remercie toute personne ayant contribu de prs ou de loin

    la ralisation de ce travail.

    Un grand merci tous

  • Sommaire

    Rsums

    Liste des abrviations

    Liste des figures

    Liste des tableaux

    Introduction ........................................................................................................................... 1

    Partie bibliographique

    Chapitre I

    Proprits biologiques de Rhamnus alaternus L.

    1. Proprits botaniques ..................................................................................................... 2

    1.1. Gnralits ............................................................................................................. 2

    1.2. Classification .......................................................................................................... 2

    1.3. Caractristiques morphologiques ............................................................................ 2

    1.4. Nomenclature ......................................................................................................... 5

    1.5. Ecologie et rpartition gographique ....................................................................... 5

    2. Usage traditionnel .......................................................................................................... 5

    3. Proprits biochimiques ............................................................................................. 5

    Chapitre II

    Les polyphnols

    1. Les composs phnoliques ............................................................................................. 7

    1.1. Gnralits ............................................................................................................. 7

    1.2. Biosynthse des composs phnoliques .................................................................. 7

    1.3. Principales classes des polyphnols ........................................................................ 8

    2. Activits biologiques .................................................................................................... 14

    2.1. Activit antioxydante ............................................................................................ 14

    2.2. Activit antimicrobienne ........................................................................................... 17

  • Partie Exprimentale

    Chapitre III

    MATERIEL ET METHODES

    1. Matriel ........................................................................................................................ 20

    1.1. Matriel vgtal .................................................................................................... 20

    1.2. Appareils et produits chimiques ............................................................................ 20

    1.3. Les souches microbiennes utilises ....................................................................... 20

    2. Mthodes danalyses .................................................................................................... 21

    2.1. Prparation des extraits ......................................................................................... 21

    1.2. Analyse chimique ................................................................................................. 25

    1.3. Activit antioxydante ............................................................................................ 27

    1.4. Activit antimicrobienne ....................................................................................... 29

    Chapitre VI

    Rsultats et discussion

    1. Rsultats et discussion .................................................................................................. 31

    1.1. Rendements des extractions .................................................................................. 31

    1.2. Composition chimique .......................................................................................... 31

    1.3. Lactivit antioxydante et antiradicalaire .............................................................. 37

    1.4. Lactivit antimicrobienne .................................................................................... 46

    Conclusion ........................................................................................................................... 58

    Rfrences bibliographiques ................................................................................................ 59

    Annexes ............................................................................................................................... 67

  • Rhamnaceae Rhamnus alaternus (EMTF) .

    . %10 %11 (EMR) Soxhlet )/( %8 %6( EAR( )EATF )

    Folin-Ciocalteu. , (EMTF) (EATF) / 7 36

    ( EAR) (EMR) / 19 7 / 5 AlCl3 18 14 6

    EATF ,EAR ,EMTF ,EMR / . 2 2 6 7

    % 82 72 / BHT 95 % 50 /. 2 % (CI50) 2,2 -diphenyl-

    1-picrylhydrazyl (DPPH.) 52 37 BHT EMR . EMTF / 71 EAR EATF 66

    3 + 11 (CMI). (EMR)

    .P/ 0.2 E. coli S. aureus K. pneumoniae E. faecalis/ : 6,25 aeruginosa.

    , , .. Rhamnus alaternus ,

  • Abstract

    Rhamnus alaternus L. a shrub which belongs to the Rhamnaceae family. Its a

    medicinal plant largely used in Algerian traditional medicine. The aerial parts of the plant

    (stems and leaves) were subjected to maceration in methanol (EMTF), whereas the roots were

    extracted with methanol (EMR) using a Soxhlet apparatus. The decoction has been conducted

    both on the aerial parts (EATF) and roots (EAR) using distilled water. The yields were 11 %,

    10 %, 6 % and 8 % (w/w) for EMTF, EMR, EATF and EAR respectively. Total phenolic

    contents were determined using Folin-Ciocalteu reagent and found to be 36 (EATF), 19

    (EAR), 7 (EMTF) and 7 (EMR) mg cafeic acid equivalent/ g of fresh weight. Flavonoids were

    evaluated by AlCl3 method and shown to be 18 (EATF), 14 (EAR), 6 (EMTF) and 5 (EMR)

    mg quercetin equivalent/ g of fresh weight. The flavones and flavonols were estimated to be 7

    (EATF), 6 (EAR), 2 (EMTF) and 2 (EMR) mg quercetin equivalent/ g of fresh weight.

    Antioxidant activity was evaluated using -carotene/linoleic acid system, it ranged between

    72 and 82 % for all extracts and seems to be closed to that of BHT 95 % when used at 2

    mg/ml. Free radical scavenging effects were evaluated using 2,2-diphenyl-1-picrylhydrazyl

    (DPPH.), The 50 percent inhibitory concentration for DPPH

    . (IC50) were 37 (BHT), 52

    (EMR), 66 (EATF), 66 (EAR) and 71 g/ml (EMTF). The antimicrobial sensitivity of the

    extracts towards eleven bacterial strains (Gram+ and Gram-) and three fungi strains was

    assessed using to the disc diffusion agar test; only one extract (EMR) has developed an

    inhibitory effect against five bacteria tested namely E.coli, S.aureus, K. pneumoniae , E.

    faecalis and P.aeruginosa. The minimal Inhibitory Concentrations (MICs) was 0,2 mg/ml for

    P.aeruginosa and 6,25 mg/ml for the remaining bacteria.

    Key word: phenolic content, Rhamnus alaternus L., antimicrobial activity, antioxidant

    activity.

  • Rsum

    Rhamn

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