1. introduction -...

Biological activities of Limonia crenulata (Roxb.) 1

1. INTRODUCTION

Medicinal plants (MPs) played a significant role in various ancient traditional

systems of medication such as Ayurvedic, Siddha and Unanic in India. Herbal medicine

is the oldest and still the most widely used system of medicine in the world today. It is

used in all societies and is common to all cultures. According to World Health

Organization (WHO), Herbal Medicine is defined as plant derived material or

preparation, which contains raw or processed ingredients from one or more plants, with

therapeutic values (Chapman and Chomchalow, 2004).

The WHO estimates that a minimum of 20,000 plant taxa has recorded medicinal

uses. It is estimated that up to 70,000 plants species are used in folk medicine and a

majority of these species are found in the Asia-Pacific region (Batugal, 2004). Interest in

the exploitation of medicinal and aromatic plants as pharmaceuticals, herbal remedies,

flavourings, perfumes and cosmetics, and other natural products has greatly increased in

the recent years (Anonymous 1994; Ayensu 1996; Salleh et al. 1997; Kumar et al. 2000).

As with many other economic plants that are still being collected from the wild and

exploited by humans unsustainably, threats to genetic diversity and species survival have

also increased in the case of medicinal plants as a result of habitat destruction, over-

exploitation, land use changes and other pressures (Arora and Engels 1993). In India

alone, less than 10 % of the medicinal plants traded in the country are cultivated, about

90% are collected from the wild, very often in a destructive and unsustainable manner

(Natesh, 2000).


The number of organizations conducting research and other activities related to

the use of medicinal and aromatic plants is large and increasing (Ayensu 1996; Sharma et

al., 2002). Botanic gardens are particularly well distributed network of institutions with

experience and expertise in this area. Work on conservation of this resource, particularly

at the level of intra-specific genetic diversity, has not kept pace with advances in other

areas, such as pharmacognosy and documentation of indigenous knowledge (Leaman et

al., 1999; Kshirsagar and Singh 2001). The medicinal plants have been used by humans

from the pre-historical times. Studies have pointed out that many drugs that are used in

commerce have come from folk-use and use of plants by indigenous cultures

(Anonymous, 1994).

Of the 2,50,000 higher plant species on earth, more than 80,000 are medicinal.

India is one of the world’s 12 biodiversity centres with the presence of over 45000

different plant species. India’s diversity is unmatched due to the presence of 16 different

agro-climatic zones, 10 vegetation zones, 25 biotic provinces and 426 biomes (habitats of

specific species). Of these, about 15000-20000 plants have good medicinal value.

However, only 7000-7500 species are used for their medicinal values by traditional

communities. In India, drugs of herbal origin have been used in traditional systems of

medicines such as Unani and Ayurveda since ancient times. The Ayurveda system of

medicine uses about 700 species, Unani 700, Siddha 600, Amchi 600 and modern

medicine around 30 species. The drugs are derived either from the whole plant or from

different organs, like leaves, stem, bark, root, flower, seed, etc. Some drugs are prepared

from excretory plant product such as gum, resins and latex. Even the Allopathic system


of medicine has adopted a number of plant-derived drugs which form an important

segment of the modern pharmacopoeia. Some important chemical intermediates needed

for manufacturing the modern drugs are also obtained from plants (Eg. diosgenin,

solasodine, and ionone). Not only, that plant-derived drug offers a stable market world

wide, but also plants continue to be an important source for new drugs (Joy et al., 1998).

Medicinal plants, as a group, comprise approximately 8000 species and account

for about 50% of all the higher flowering plant species in India. A large number of the

country's rural population depends on medicinal plants for treating various illnesses.

About 1.5 million practitioners of the Indian Systems of Medicine and Homeopathy (ISM

&H) use medicinal plants for preventive, promotive and curative applications.

Furthermore, there are 7,843 registered ISM pharmacies and 851 of homoeopathy as well

as a number of unlicensed small-scale units. Besides meeting national demands, India

caters to 12% of the global herbal trade. In recent years, trade in herbal-based products

has quantum leaped, particularly in the volume of plant material traded within and

outside the country. Estimates by the EXIM (Export – Import) Bank put medicinal plants

related international trade at US$ 60 billion per year and still growing at a rate of 7%

annually (Maiti, 2004).

India is blessed with two mega centres of biodiversity such as the Hindustan

Centre of Origin and the Central Asia Centre of Origin. This biodiversity is mainly

distributed in Western Ghat, North Eastern India and the Himalayan Region. India has

about 141 endemic genera of 5,150 species belonging to 47 families of higher plants.

Among the different endemic species, 2,532 species are distributed in Himalayas, 1,788


species in the peninsular region and 185 species in the Andaman and Nicobar Islands.

About 43,000 plant species are eferred to Indian folklore but only about 1,700 plant

species have actually been documented in old literature (Maiti, 2004).

Over three quarters of the world population relies mainly on plants and plant

extracts for health care. More than 30% of the entire plant species, at one time or other,

were used for medicinal purposes. It is estimated that world market for plant derived

drugs may account for about Rs. 2,00,000 crores. Presently, Indian contribution is less

than Rs. 2000 crores. Indian export of raw drugs has steadily grown at 26% to Rs. 165

crores in 1994 - 1995 from Rs. 130 crores in 1991-1992. The annual production of

medicinal and aromatic plant’s raw material is worth about Rs.200 crores. This is likely

to touch US $1150 by the year 2000 and US $5 trillion by 2050 (Joy et al., 1998).

Over 7000 species belonging mainly to the families Fabaceae, Euphorbiaceae,

Asteraceae, Poaceae, Cucurbitaceae, Apiaceae, Convolvulaceae, Malvaceae, Rutaceae

and Solanaceae have been used from ancient times by various indigenous peoples in the

country. This number corresponds to more than 25% of the world's known medicinal

plants, estimated to be at around 30,000 species. Analyses of these plants show that they

include all the major life forms (i.e., trees, shrubs, climbers and herbs), with the

proportion of ferns and lichens being much smaller compared to flowering plants (Maiti,

2004).


Nature has been a source of medicinal agents for thousands of years and an

impressive number of modern drugs have been isolated from natural sources, many based

on their use in traditional medicine. Plants produce a diverse range of bioactive

molecules, making them a rich source of different types of medicines. For most of the

developing world, the main issue of public health is still the acute need for basic health

care, which is sadly lacking even at the most elementary level. This is true in both the

rapidly growing cities and in the rural areas. The WHO indicates that more than half of

the world's population does not have access to adequate health care services. This is due

to the fact that poor people neither have access to nor could afford the present health care

services. Therefore, innovative alternative approaches are needed to address this problem.

The use of plants for treating various diseases predates human history and forms

the origin of much of the modern medicine. Long before the advent of modern medicine,

herbs were the mainstream remedies for nearly all ailments. People commonly diagnosed

their own illness, prepared and prescribed their own herbal medicines, or bought them

from the local apothecaries.

Using plants as medicine provides significant advantages for treating many

conditions. The therapeutic activity of a plant is due to its complex nature with different

parts of the plant providing certain therapeutic effects.

Today we are witnessing a great deal of public interest in the use of herbal

remedies. The WHO estimated that 80% of the earth's inhabitants rely on traditional


medicine for their primary health care needs and most of this therapy involves the use of

plant extracts or their active components (Batugal, 2004).

Herbal medicines are being used increasingly as dietary supplements to fight or

prevent common maladies like cancer, heart attacks and depression. When added to foods

as supplements, herbs have also been termed as neutraceuticals. Herbal remedies are

unpurified plant extracts containing several constituents, which often work together

synergistically.

Health practices, approaches knowledge's and benefits incorporating plant, animal

and mineral based medicines. Applied singularly or in combination to treat, diagnose and

prevent illness or maintain well-being. In Africa upto 80% of the populations use

traditional medicines for primary health care. In industrialized countries, adaptations of

traditional medicine re-termed Complementary or Alternative Medicine (CAM). In

United States, 158 millions of the adult population use complementary medicine, US$ 17

billion was spent on traditional remedies in 2000. In the United Kingdom, annual

expenditure an alternative medicine was US $ 230 million. The global market for herbal

medicines currently stands at over US $ 60 billion annual and is growing steadily 25% of

modern medicines are made from plants first use traditionally.

Over one third of the population in developing countries lack access to essential

medicines. The provision of safe effective traditional medicine therapies could became a

critical tool to increase access to health care.


70 countries have a national regulation on herbal medicines but the legislative

control of medicinal plants has not evolved around a structured model. This is because

medicinal products or herbs are defined differently in different countries and diverse

approaches have been adopted with regard to licensing, dispensing, manufacturing and

trading (WHO, 2008).

Indian sub continent is a rich source of plant and animal wealth, which is due to

it's varied geographical and agroclimatic regions. Beside it is varied bio-diversity, it has

a diverse cultural heritage too. Though at present Indian health care delivery consists of

both modern system of medicines and traditional system of medicine like Ayurveda,

Siddha, Unani and unorganized system like Folk-medicine have been flourishing well.

Ayurveda and Siddha are of Indian origin and accounted for about 60% health care

delivery in general and 75% of rural Indian population depends on these traditional

systems.

These two systems of medicine used plants, minerals, metals and animals as a

source of drugs, plants being the major source. It is estimated that roughly 1,550 plant

species in Ayurveda and 1,200 plant species in Siddha have been used for drug

preparation (Jain, 1991; Krishnakumar and Sureshkumar, 1995). In Indian Folk medicine

use of about 7,500 plant species are recorded as medical plants (Anonymous, 1996).


Homeopathy system of medicine is a newer one which has been developed in 18th

century by Samuel Hahnemann a German Physician and Chemist. These systems based

on the concept of providing and prove (Treatment and Patient) that is the choice of drug

for treatment depends on symptoms and the clinical condition of the patient (Kokate,

1994).

Nowadays peoples are attracted towards modern system of medicine because of

sudden relief from illness, availability etc. But the trend has been changing now, because

of side effect, low cost and more efficacy than the modern medicine consequently does it

has been a demand for herbs and their products.

The major problem in quality control of herbal drug is lack of Pharmacological

standards for all medicinal plants used in phyto drug making. Recently published Indian

herbal pharmacopeias contain only a few (32) medicinal plants against about 500 drugs

Indian medicine manufactures are used the plants by their products. It is ironical that

even botanical identity of many herbs used in medicinal plant is known in different

vernacular names in different parts of India.

India is one of the 12 mega biodiversity centers of the world. The country is

divided into 10 biogeography zones, and 25 hot spots representing all the major

ecosystems. India is recognized as a country rich in biodiversity because of its tropical

location, varied physical features and climate. These factors altogether have resulted in a

diversity of ecological habitats like forests, grass land, wet lands, marine and desert

ecosystems which harbors immense biodiversity. Indian biodiversity represents 7 percent


of world flora and 6.5 percent of world fauna. In general, nearly 45,000 plant species and

81,000 animal species constitute India's biodiversity. The Indian flora Limonia crenulata

(Roxb.) is a well known medicinal plant. All parts of this plant are medicinally useful.

Literature in Indian traditional medicinal systems like Ayurveda, Siddha, Unani and

Indian folk medicine has potential information on its therapeutic uses. Leaf, fruits and

roots of this plant is used to treat dyspepsia, diarrhoea, fever and diabetes.

Traditional medicines (TM) have been defined by WHO as "diverse health

practices, approaches, knowledge and beliefs incorporating plant, animal and or mineral

based medicines, spiritual therapies, manual techniques and exercises applied singularly

or in combination to maintain well being, as well as to treat, diagnose or prevent illness".

The advantages of traditional medicine include its widespread accessibility and

relative cheapness, when most people in low income countries pay for medicines out of

their own pockets. The government of China and India, amongst others, provides

governmental support to strengthen training, research and the use of "traditional"

medicine in their national health care strategies and a number of African countries are

considering how to integrate traditional medicine into "main stream" health care. The

possibilities for expanding such initiatives need to be examined. Apart from medical use,

the production, sale and export of traditional medicine is an important component in

some economies. China for instance, exports over 600 million dollars of traditional

medicine products annually. Chinese health authorities have recently launched a nation

wide program to build up Traditional Chinese Medicine (TCM) hospitals, each


specializing in the treatment of a particular condition, such as different types of cancers,

heart and vascular diseases and hepatitis (Hepeng, 2004.)

Efficacy traditional medicine of is one of the most debated issues. There are

philosophical, cultural, technical, methodological and practical aspects involved in

efficacy or otherwise have been published in prestigious international scientific journals.

For instance, the efficacy of acupuncture in relieving pain and nausea has been well

demonstrated and is now acknowledge world wide. For herbal medicines, some of the

best-known evidence of efficacy of an herbal product includes Artemisia annua for the

treatment of malaria, St. John's wort for the management of mild to moderate depression.

Patients usually experience fewer side effects than when treated with antidepressants such

as amitriptyline. Such findings have inspired research worldwide to establish the efficacy

of other extensively used TM. Many plant extracts have a variety of pharmacological

effects, including anti inflammatory vasodilatory, antimicrobial, anticonvulsant, sedative

and antipyretic effects. However, very few randomized controlled studies have been

carried out to investigate the practice and treatment delivery of herbal practitioners in

their every day work. Regarding no medication therapies, the 1999 British Medical

Journal (BMJ) series on CAM commented that randomized controlled trials have

provided good evidence that both hypnologic and relaxation techniques can reduce

anxiety and prevent panic disorders and insomnia. It has also shown hypnosis to be of

value in treating asthma and irritable bowel syndrome. Yoga is to be of benefit in asthma

and in helping elderly people to reduce their fear of falls. Besides these limitations, there


has been an enormous research that has been and is underway in many institutions

globally. Many of the findings do substantiate the traditional claims (Patwardhan, 2005).

The major advantage of herbal medicines over modern medicine is the substantial

absence of serious side effects of herbs compared with pharmaceutical medicines. Herbs

have traditionally been used in cooking as well as in the healing arts.

Pharmaceutical medicines are their copies of herbal "active ingredient" are

completely new molecules that do not occur in nature. People also tend to believe that

natural products are inherently better than synthetic drugs. The natural drugs somehow

contain the 'vital force' that is going to improve their health. The promise is of alternative

and effective treatment for chronic disorders. The risk is borne out of the great-unknown

effects of herbs on the human body. People who use herbal medicines for self-diagnosed

ailments run potential health risks. The risks involve people of all ages (Litvinenko, et

al., 1992).

Nowadays traditional medicines and practices form an integral part of

Complementary and Alternative Medicine (CAM). Although their efficacy and

mechanisms of action have not been tested scientifically in most cases, these simple

medicinal preparations often mediate beneficial responses due to their active chemical

constituents (Park and Pezzuto, 2002).


The use of plant compounds for pharmaceutical purposes has gradually increased

in the world. Various medicinal plants have been used as a source of medicine for years

in daily life to treat diseases. Over 50% of all modern clinical drugs are of natural product

origin (Stuffness and Dourous, 1982).

Ethnopharmacology provides an alternative approach for the discovery of

antibacterial agents, namely the study of medicinal plants with a history of traditional use

as a potential source of substances with significant pharmacological and biological

activities (Pushpangadan, 1995).

Phytoconstituents are the natural bioactive compounds found in plants. These

phytoconstituents work with nutrients and fibers to form an integrated part of defense

system against various diseases and stress conditions. Phytochemicals are basically

divided into two groups, i.e. primary and secondary constituents; according to their

functions in plant metabolism. Primary constituents comprises common sugars, amino

acid, proteins and chlorophyll while secondary constituents consists of alkaloids,

terpenoids, saponins, phenolic compounds, flavonoids, tannins, etc.

Pharmacognosy means knowledge of drugs which is mainly concerned with

naturally occurring substances this term was introduced by Seydler in 1815 in his work

entitled ‘Analecta pharmacognostica' (Evans, 1983). In other words it is an applied

science that deals with biological, biochemical and economical features of natural drugs

and their constituents (Tyler et al., 1981). Natural drugs are originated either from plant


or animal origin. In the earlier days, only the morphological characters were used to

identify the drugs. In the beginning of the present century, pharmacognosy had developed

on the botanical side which is concerned with the description and identification of drugs

both in whole and powdered states. Therapeutic efficacy of herbal drugs depends upon

the quality and quantity of the active compounds that they contain. Pharmacognosy is the

simultaneous application of various specific disciplines with the object of acquiring

knowledge of drugs from every point of view.

Many higher plants are major sources of natural products used as pharmaceutical

agrochemicals, flavour and fragrance ingredients, food additives and pesticides. The

search for new plant derived chemicals should be a priority in current and future efforts

towards sustainable conservation and rational utilization of biodiversity. Secondary

metabolism in a plant plays a major role in the survival of the plant in its environment.

Attraction of pollinators, defense against predators and diseases are examples of the roles

of secondary metabolites. Moreover, numerous plant secondary metabolites such as

alkaloids, anthocyanins, flavonoids, tannins, fixed oil, resin, vitamin C, vitamin E,

carbohydrate, protein and phytosterols have found commercial application as drug, dye,

flavour, fragrance, insecticide etc. Such fine chemicals are extracted and purified from

plant materials. The extraction is done by using different solvents. The crude extracts are

further purified and the chemical structures of the purified material can then be analysed.

Techniques for further chemical analysis include chromatography, bioautography,

radioimmunino assay, various methods of structure identification and newer tools such as

fast Atom Bombardment Mass Spectrometry (ABMS), Tandem Mass Spectroscopy


(TMS), High Performance Liquid Chromatography (HPLC), Capillary Zone

Electrophoresis (CZE), Nuclear Magnetic Resonance Spectroscopy (NMRS), and X-ray

Crystallography (Cowan, 1999).

It has been well known since ancient times that plants and spices have

antimicrobial activity. There has been a considerable interest to use plants and spices for

the elimination of microorganisms because of increasing antibiotic resistance of

microorganisms. The phytochemical analysis can be carried out to determine the presence

of carbohydrates, glycosides, proteins, amino acids, phytosterols, saponins, flavonoids,

alkaloids and tannins using various solvents. These compounds are taken for

characterization that can be done by different methods. Laboratories of the world have

found literally thousands of phytochemicals which have inhibitory effects on all types of

microorganisms in vitro. More of these compounds should be subject to animal and

human studies to determine their effectiveness in whole-organism systems, including in

particular toxicity studies as well as an examination of their effects on beneficial normal

microbiota. It would be advantageous to standardize methods of extraction and in vitro

testing so that the search could be more systematic and interpretation of results would be

facilitated.

Heterocyclic nitrogen compounds are called alkaloids. The first medically useful

example of an alkaloid was morphine, isolated in 1805 from the Opium poppy, (Papaver

somniferum). Solamargine, a glycoalkaloid from the berries of Solanum khasianum and

other alkaloids may be useful against Human Immunodeficiency Virus (HIV) infection as


well as intestinal infections associated with Acquired immune deficiency syndrome

(AIDS). Berberine is an important representative of the alkaloid group. It is potentially

effective against trypanosomes and plasmodia. The mechanism of action of highly

aromatic plant quaternary alkaloids such as berberine and harmane is attributed to their

ability to intercalate with DNA.

Some of the simplest bioactive phytochemicals consist of a single substituted

phenolic ring. Cinnamic and caffeic acids are common representatives of a wide group of

phenyl propane derived compounds which are in the highest oxidation state. The common

herbs Tarragon and Thyme both contain caffeic acid, which is effective against viruses,

bacteria and fungi. Phenolic compounds possessing a C3 side chain at a lower level of

oxidation state and containing no oxygen are classified as essential oils and often cited as

antimicrobial as well.

Flavones are phenolic structures containing one carbonyl group. The addition of a

3-hydroxyl group yields a flavonol. Flavonoids are also hydroxylated phenolic substances

but occur as a C6-C3 unit linked to an aromatic ring. Since they are known to be

synthesized by plants in response to microbial infection, it should not be surprising that

they have been found in vitro to be effective antimicrobial substances against a wide

array of microorganisms. Lipophilic flavonoids may also disrupt microbial membranes.

Tannin is a general descriptive name for a group of polymeric phenolic substances

capable of tanning leather or precipitating gelatin from solution, a property known as


astringency. Their molecular weights range from 500 to 3,000 and they are found in

almost every plant part bark, wood, leaves, fruits and roots. They are divided into two

groups, hydrolyzable and condensed tannins. Many human physiological activities, such

as stimulation of phagocytic cells, host mediated tumour activity and a wide range of

anti-infective actions, have been assigned to tannins. Condensed tannins have been

determined to bind cell walls of luminal bacteria, preventing growth and protease

activity.

The fragrance of plants is carried in the so called quinta essential, or essential oil

fraction. These oils are secondary metabolites that are highly enriched in compounds

based on an isoprene structure. They are called terpenes, their general chemical structure

is C10S16 and they occur as diterpenes, triterpenes and tetraterpenes as well as

hemiterpenes and sesquiterpenes. When the compounds contain additional elements,

usually oxygen, they are termed terpenoids. Terpenes or terpenoids are active against

bacteria, fungi and virus.

Papaya yields a milky sap, often called latex, which is a complex mixture of

chemicals. Chief among them is papain, a well known proteolytic enzyme. An alkaloid,

taparin, is also present. Terpenoids are also present and may contribute to its

antimicrobial properties. Propolis is an extract of the balsam of various trees; it is often

called bee glue, since honeybees gather it from the trees. Its chemical composition is very

complex, like the latex, terpenoids are present as well as flavonoids, benzoic acids,

substituted phenolic acids and esters (Amoros et al., 1992).


Pharmacognosy is the study of medicines derived from natural sources, including

plants. The American Society of Pharmacognosy (ASP) as "the study of the physical,

chemical, biochemical and biological properties of drugs, drug substances or potential

drugs or drug substances of natural origin as well as the search for new drugs from

natural sources."

It has been estimated that in developed countries such as United States, plant

drugs constitute as much as 25% of the total drugs, while in fast developing countries

such as China and India, the contribution is as much as 80%. Thus, the economic

importance of medicinal plants is much more to countries such as India than to rest of the

world. These countries provide two third of the plants used in modern system of medicine

and the health care system of rural population depend on indigenous systems of medicine.

Research interest has focused on various herbs that possess hypoglycemic, anti

platelet, antitumor, or immune - stimulating properties that may by useful adjuncts in

helping reduce the risk of various diseases. In different herbs a wide variety of active

phytochemical, including the flavanoids, terpenoids, lignans, sulfides, polyphenolics,

carotenoids, coumarins, saponins, plant sterols, curcumins, and phthalides have been

identified (Tyler, 1981).

Traditional knowledge of medicinal plants has always been a valuable guide in

the quest for new medicines. In spite of the advent of modern high therapeutic drug


discovery and screening techniques, traditional knowledge systems have given clues to

the discovery of valuable drugs (Buenz et al., 2004). Traditional medicine offers distinct

advantages even in modern times because they are often cheaper, locally available, and

easily consumable as raw or simple medicinal preparations. Their role is still more

predominant in developing countries.

Nature can be considered as the ultimate chemist as natural products offer us with

an abundant source of novel chemo-types, pharmocophores or lead structures, which

could be directly used or derived into readymade drugs. Plants and microbes offer us

with a lucrative diversity for screening of the novel bioactivities. Thus nature remains as

the potential source of organic structures of unparalleled diversity.

A number of enhancements can be made to the basic method of thin layer

chromatography to automate the different steps, to increase the resolution achieved and to

allow more accurate quantitative measurements.

Gas chromatography-mass spectrometry (GC-MS) is a method that combines the

features of gas-liquid chromatography and mass spectrometry to identify different

substances within a test sample. Applications of GC-MS include drug detection, fire

investigation, environmental analysis, explosives investigation, and identification of

unknown samples. GC - MS can also be used in airport security to detect

substances in luggage or on human beings. Additionally, it can identify trace elements in

materials that were previously thought to have disintegrated beyond identification.


High-performance liquid chromatography (or high-pressure liquid

chromatography, HPLC) is a chromatographic technique that can separate a mixture of

compounds and is used in biochemistry and analytical chemistry to identify, quantify and

purify the individual components of the mixture.

The pharmacological industries have produced a number of new antibiotics in the

last three decades resistance to these drugs by microorganisms has increased. In general

bacteria have the genetic ability to transmit and acquire resistance to drugs, which are

utilized as therapeutic agents. Such a fact is cause for concern, because of the number of

patients in hospitals who have suppressed immunity, and due to new bacterial strains

which are multiresistant. The problem of microbial resistance is growing and the outlook

for the use of antimicrobial drugs in the future is still uncertain. Therefore actions must

be taken to reduce this problem, for example, to control the use of antibiotic, develop

research to better understand the genetic mechanisms of resistance, and to continue

studies to develop new drugs. The use of plant extracts and phytochemicals both with

known antimicrobial properties can be of great significance in therapeutic treatments. In

the last few years, a number of studies have been conducted in different countries to

prove such efficiency. Many plants have been used because of their antimicrobial traits,

which are due to compounds synthesized in the secondary metabolism of the plant.

Plant generally produces many secondary metabolites which constitute an

important source of microbicides, pesticides and many pharmaceutical drugs. Plant


products still remain the principle source of pharmaceutical agent used in traditional

medicine (Ibrahim, 1997; Ogundipe and Akinbiya, 1998). Since the introduction of

antibiotics there has been tremendous increase in the resistance of diverse bacterial

pathogens (Cohen, 1992; Gold and Moellering, 1996). Plant derived products have been

used for medicinal purposes for centuries.

Since ancient times, plants have been model source of medicines as they are a

reservoir of chemical agents with therapeutic properties. The general population is

increasingly using herbal medicines as dietary supplements to relieve and treat many

different human disorders. It has been well known since ancient times that plants and

spices have antimicrobial activity (Ayres et al., 1980; Zaika, 1988).

Plants have been used as folk remedies and ethno botanical literature has

described the usage of plant extracts, infusions and powders for centuries for diseases

now known to be of bacterial origin. There is an increasing need for search of new

compounds with antibacterial activity as the treatment of bacterial infections with the

available antibacterial drugs is often unsatisfactory due to the problem of bacterial

resistance coupled with the problem of bacterial latency and conflicting efficacy in

recurrent infection in immunocompromised patients (Vlietinck and Vanden Berghe,

1991).

A number of compounds extracted from various species of higher plants have

shown antibacterial activity (Fukuchi, et al., 1989). There has been a considerable


interest to use plants for the elimination of microorganisms because of increasing

antibiotic resistance of microorganisms (Kunin, 1993; Finch, 1998; Smid and Gorris,

1999).

The problem of microbial resistance is growing and the outlook for the use of

antimicrobial drugs in the future is still uncertain. Therefore, there is a need for the

development of new drugs to reduce this problem. In general bacteria and fungi have the

genetic ability to transmit and acquire resistance to drugs, which are utilized as

therapeutic agents (Cohen, 1992).

Anti-inflammatory refers to the property of a substance or treatment that reduces

inflammation. Anti-inflammatory drugs make up about half of analgesics, remedying

pain by reducing inflammation as opposed to opioids which affect the central nervous

system.

A recent review of references indicates that the antiulcerogenic effects of many

taxa of medicinal plants have been assessed worldwide (Yesilada and Gurbuz, 2003). It is

also reported that many plant species have been used to alleviate gastric symptoms such

as gastric pain, etc.

Diarrhoeal diseases are one of the leading causes of morbidity and mortality in

developing countries and are responsible for the death of millions of people each year..

Despite immense technological advancement in modern medicine, many people in the


developing countries still rely on the healing practices and medicinal plants for their daily

health care needs. Therefore, the WHO encouraged studies for the treatment and

prevention of diarrhoeal diseases depending on traditional medical practices.

Diarrhoea is an alteration in normal bowel movement and is characterized by an

increase in the water content, volume, or frequency of stools. Plants have long been a

very important source of new drugs. Many plant species have been screened for

substances with therapeutic activity. Medicinal plants are a promising source of

antidiarrhoeal drugs with this reason, international organizations including the studies and

research on Diarrhoea.

World Health Organization (WHO) has encouraged studies pertaining to the

treatment and prevention of diarrhoeal diseases using traditional medical practices.

In the development of medicine from plants, four important steps are involved:

identification of suitable plants to investigate

isolation and identification of single chemical entities from the chosen plant

identification of the pharmacological actions of those entities

conduct of controlled clinical trials

Herbal medicine is increasingly being validated by scientific investigation which

seeks to understand the active chemistry of the plant. Many modern pharmaceuticals

have been modeled on, or derived from chemicals found in plants.


The present need for development of new therapeutic agents from natural sources

had made the researchers to refresh and uncoil the literatures. Development of suitable

methods for effective isolation of bioactive compounds and reliable analytical techniques

are research perspectives.

In recent years, medicinal plants have attracted global interest as they constitute a

rich treasure of improved cultural information and are sources of natural products, which

provide health security to millions in rural communities. There is a growing tendency all

over the world to shift from synthetic to natural based projects including medicinal

plants. The first half of the twentieth century was a period of tremendous advancements

in medicine as causes of diseases were uncovered and new miracle drugs were isolated

and synthesized. Initially, many modern medicines were isolated products from

traditional plant derived extracts.

In the present scenario of emergence of multiple drug resistance to human

pathogenic organism, search for now, safe and effective therapeutical agents from other

source including plants are urgently needed. Anti-microbial agents from plants are

plentiful in many countries, especially in India, where thousands of tribal communities

still use medicinal plants today to cure. It is a necessity from the scientific point of view

to establish a rational relationship between chemical, biological and therapeutical

activities of medicinal plants.


Realizing the benefit of herbal and medicinal plants and to improve the quality

and knowledge on the medicinal plants, the pharmacognostical studies with

pharmacological experimentations are essential. Nature has provided a complete

storehouse of remedies to cure all ailments of mankind and the history herbal medicine is

as old as human civilization. , India has made tremendous progress in agro-technology,

process technology, standardization, quality control, research and development etc.

Screening of medicinal plant for antimicrobial, antioxidant, anti - inflammatory,

antiulcer and antidiarrhoea for finding potential new compounds for therapeutic use.

There is a lack of scientific studies on Limonia crenulata (Roxb.).

1. introduction -...

Documents