Ethnobotany & Ethnopharmacology.pptx

1. Ethnobotany &
Ethnopharmacology
PRESENTED BY
MISS . AISHWARYA U. PHUTANE
DEPARTMENT OF PHARMACOGNOSY
MARATHWADA MITRAMANDAL’S COLLEGE OF PHARMACY THERGAON PUNE

2. Content:
 Ethnobotany in herbal drug evaluation
 Impact of ethnobotany in traditional medicine
 New development in herbals
 Bio-prospecting tools for drug discovery
 Role of ethnopharmacology in drug evaluation
 Reverse pharmacology

3. Definition:
 The scientific study of substances used medicinally, especially folk remedies, by different ethnic or
cultural groups.
 It is strictly related to plant use, Ethnobotany.
 Inventory by WHO found around 20,000 plant species in use for medicinal in various countries.
 Only 250 of those species are commonly used or have been checked for main active chemical
compounds.

4. A brief idea of Ethnopharmacology:
 Ethnoveterinary medicine is an important component of indigenous knowledge system.
 Archaeological evidences provide substantial clues that prehistoric people were aware of magical
power of plants.
 60,000 years ago Iraqi people used ephedra.
 Egyptian Eber papyrus documented about garlic and castor oil and their magical power.
 Galen the roman physician write books about medicinal plants.
 Indian charak samhita tells about details of about 350 medicinal plants.

5. Ethnobotany in herbal drug evaluation:
 Ethnobotany is the study of plant-human interrelationships embedded in dynamic ecosystems of natural and social
components.
 Plant use & plant-human interrelationships are shaped by history, by physical & social environments, & by inherent
qualities of the plants themselves.
 The object of ethnobotanical inquiry is actually a sort of “text” (Ricoeur, 1971) the meaning of which is derived
partially from the natural, social & cultural contexts in which the text is played out.
 The roles played by plants reflect the biological & physical properties of the plants, the biological and perceived
needs of humans, the natural & anthropogenic communities of which the plants are a part, & the genetically limited
responses of plants to human disturbance.
 The aims of ethnobotany are two fold:
1. To document facis about plant use & plant management.
2. To elucidate the ethnobotanical text by defining, describing,& investigating ethnobotanical roles & processes.

6. Cont:
 There are so many reasons for doing broad ethnobotanical, ethnopharmacological & even clinical
therapeutic research. Among these reasons, the following could be cited.
1. To rescue knowledge in imminent danger of being lost.
2. The utility of plants in current therapy.
3. To find new molecular models in plants.
4. The usefulness of plants in the development of physiopathology.
5. The wide use of plants in folk medicine.
6. To obtain intermediate chemicals.
Re-education is easier for those trained in field biology, but these same individuals must overcome a bias to ignore or
to classify simplistically the human component to the ecosystem under study (Anderson 1952, Posey 1984)

7. Cont:
 Ethnobotany was implicitly happed by imperialist motives (Brockway 1979).
 Collectors were sent to gather useful plants from areas occupier by traditional cultural groups & the
collected plants were used for commercial exploitation by the modern world.
 Plant have been a rich source of medicines because they produce a host of bioactive molecules, most of
which probably evolved as chemical defences against predation or infection.
 Advances in synthetic chemistry & molecular biology promised to supply new means for designing
drugs in the laboratory (Balick 1994).
 The ethnobotanical approach is actually one of several methods that can be applied in chossing plants for
pharmacological studies.
 It is estimated that 265,000 flowering species grace the earth.

8. Impact of Ethnobotany in traditional
medicine:
 Eighty percent of the world’s population relies on traditional medicine to maintain its health (weragoda,
1980).
 In recognition of the political, economic & social barriers slowing the delivey of modern biomedical
health care to most of the world’s population, the World Health Organization (WHO) has embarked upon
an ambitious program to evaluate herbal medicines (WHO, 1978; Penso, 1980; Akerele, 1985).
 Ethnobotany can contribute to strategy in two ways:
 First, ethno-ecological studies may provide models for profitable & environmentally sound multiple use
land management programs.
 Second, ethnobotanists can invoke the considerable economic potential of as yet undiscovered or
undeveloped natural natural products (Myers, 1983; Balick, 1985). Of an estimated 75,000 edible plants,
for example, only 2500 have ever been eaten with regularity, a mere 150 have entered world commerce
& a scant 20, mostly domesticated grasses, stand between human society & starvation.

9. Cont:
 The greatest economic potential of ethnobotany lies in the area of folk medicine.
 Annually worldwide sales of plant-derived pharmaceuticals currently total over $20 billion, & a great
many of these drugs were first discovered by traditional healers in folk contexts (Farnsworth 1982).
 The forests of tropical America have yielded scopolamine, cocaine, quinine & d-tubocurarine.
 If ethnobotanists are to seize upon traditional knowledge as a means of rationalizing the prevention of
threatened rain forests, they must do far more than search for new wealth.
 It is a consequence of adaptive choices that have resulted in the development of highly specialized
perceptual skills.

10. The utility of plants in current therapy:
 The enormous availability of medicines & above al, of pharmaceutical specialties, plants have a place in
current therapy.
 Such is the case of Artemisia a source of quinine.
 Behind the therapeutic success of chloroquine & its synthetic derivatives in the treatment of malaria, the
use of quinine passed into a chapter in the history of medicine.
 This process has occurred, in part, with species of plasmodium, the causative agent of malaria, to a point
that synthetic antimalerial drugs have lost such a significant part of their efficiency in the last quaeter of
the twentieth century that it has often been necessary to return to the use of quinine.
 Traditional medicine depends on a number of plants that are currently used in scientific medicine although
they have not yet been improved upon.such is the case of digitalis purpurea L & D.

11. Cont:
 The controlled studies are needed, for example, by the double blind system, to confirm the
therapeutic effect of these plants of traditional medicine in therapy.
 An inventory of medicinl plants complied by the (WHO 1978) & encompassing only ninety
member countries gave the large figure of 20,000 species, of which only 250 were of widespread
use or had been analysed to identify their main active chemical compound(s).
 The aboriginal knowledge of the fruit of centuries & in some cases, millennia of plant use. The
study of those molecules identified as “ active compounds” is indispensable.

12. New development in herbals:
 One of the problems is that some of these drugs can only be sold outside pharmacies if they claim other
than therapeutic indications. This legislation led to fantastic indication claims as for example “blood
purifier”, “to fortify heart or nerves”, or heart nutrition”.
 The dosage of the active constituents is normally quite low. It is difficult to find scientific evidence of
efficacy for such product.
 The corresponding products have to be labelled as traditionally used based on different criteria as:
1. To tonify & to fortify
2. For amelioration of subjective health conditions
3. To support organ function
4. For prophylaxis
5. As mildly active drug

13. Cont:
 Because of these aspects, we would have to consider three groups of herbal medicines, which differ with respect to
their indication claims:
1. Herbal medicines with indication proved by new controlled clinical trails
2. Those with indications proved at least by long –term traditional use which is supported by experimental data &
3. Herbal medicines with documented traditional use but without further assessment of efficacy requiring a special
labelling on the packaging of the finished drug
A. Biological diversity- role in herbal drug development:
- Natural poducts &especially those derived from higher plants have historically played a pivotal role in the discovery
of new pharmaceuticals.
- Chemicals derived from higher plants have played a central role in the history of mankind.
- Efforts to develop new, clinically effective pharmaceutical agents have relied primarily on one of five approaches,
most of which utilize existing agents in some manner as follows:

14. Cont:
1. Derivatization of existing agents.
2. Synthesis of additional analogs of existing agents with other drugs.
3. Use of combination therapy of existing agents with other drugs.
4. Improvement of delivery of existing agents to the target site.
5. Discovery of new prototype pharmaceutical agents.
- The major advantage of this approach is the likelihood of identifying new prototype drugs with quite different
chemical structures & mechanism of action & hence, lower likelihood of similar toxicities & cross resistance.
- The fundamental element of a drug discovery program is the bioassay utilized to detect preparations with the
desired biological activity.
- The bioassay protocol selected for the discovery of new prototype drugs must meet a variety of criteria.

15. Cont:
- The probability of selection & procurement of novel sources of potential preparations must be
demonstrated as well as evidence of competency to accomplish bioassay – directed purification &
structure elucidation.
- Initially detected activity must be confirmed in suitable secondary & teryiary assays, which will help
to define the potential of the substance for clinical utility.
• Pharmaceutical potentials from plants:
Several factors have contributed to the revival of interest in plant- derived products as follows:
1. There is an undisputed clinical efficacy of several natural product anticancer drugs. The early
discovery of vincristine/vinblastine from catharanthus roseus was followed by other agents including
the aryl lignam etoposide derived from podophyllum species (mayapple) & the toxoids from taxus
brevifolia (pacific yew) & T. baccata ( European yew).

16. Cont:
2. Compounds with less direct therapeutic potential may offer new molecular templates for the design
of more effective drugs e.g. the development of atracurium & related muscle relaxants from the
alkaloids of curare, the south American dart poison obtained from chondro dendron tomentosum.
3. Natural products can offer an alternative to established therapy because they act at a different
stages in the disease, & be useful in combination therapy. The search for synthetic molecules
active against human immunodeficiency virus (HIV) has resulted largely in reverse transcriptase
inhibitors, but investigations into plant extracts have produced a wide range of chemical
compounds with various modes of action that result in viral non- proliferation.
4. Plants have proved invaluable as inexpensive sources of “feedstock” molecules that can be readily
transformed into drugs. Thus, development of the steroid- based oral contracepatives would have
been virtually impossible without plentiful supplies of compounds from the processing of the
steroidal components of plants such as yams & sisal.

17. Cont:
B. Drug discovery from natural products:
 All the wonderful progress of synthetic chemistry & of science in genral, unfortunately, has not served
to alleviate & cure all the sickness in the world.
 One positive aspect of the use of medicinal plants is their low cost compared to to the high price of
new synthetic drugs, which have become totally inaccessible to the vast majority of people.
 Favour of the use of medicinal plants, they are the only recourse available is that they have
comparatively few side effects.
 The natural products have played the major role in drug discovery.
 Different route for the discovery of the drugs from various sources has been described in the
subsequent sections.

18. Cont:
• The ethnobotanical route:
- Man & perhaps some of his closer relatives, has always made use of plants to treat illness
& many of these remedies have real beneficial effects.
Selection
preparation procurement
Natural products
Bioassay
Isolation & characterization Structure
Of active constituents elucidation
Secondary screen
Tertiary screen
Pre-clinical development

19. • Bioassay & screening:
 Bioassay & screening large numbers of compounds is favoured by many pharmaceutical companies.
 Many of these assays are based on isolated cells or enzymes & are automated to allow the thoughput
of very large numbers of samples ( Hobden & Harris 1992).
 One example of a success deriving from a more traditional bioassay approach was the identification
of the anti-implantation compound yuehchukene, which arose through the WHO fertility control
program ( Waterman1992). First , selection of plants to be tested was driven by ethanobotanical
considerations & the source of yuehchukene, murraya paniculate was include. Second, M. paniculate
was a much investigated species.
 Second example of bioassay –guided serendipity is the identification of the anti-inflammatory
activity of the octonordammarane triterpene mansumbinone & the corresponding seco A-ring
derivative mansumbionic acid, isolated from the resin of an African species of commiphora,
Burseraceae.

20.  The distribution of secondary metabolites is not random. Yuehchukene 4 is a classic example.
 It was recognized that this alkaloid was only to be found in frustratingly small amounts in murraya
paniculate, then consideration was given to other natural sources.
 This led to a search among other species of murraya & among species of the allied genera
Glycosmis, Clausena, Merrillia & Micromelum.
• chemical ecology:
- The current view of many ecologists is that while secondary metabolites may not have been
produced primarily for the purpose of defence of the organism, a large subset of them are maintained,
against an appreciable cost of production, because they do improve the fitness of yhe producer.
- One example is the identification of an antifungal flavonol by examining the biochemical response of
the leaves of Myrica gale to the effects of stimulated herbivory.
• Chemotaxonomy:

21. Bio-prospecting tools for drug
discovery:
What is bioprospecting?
• Bioprospecting, also known as biodiversity prospecting, is the exploration of biological material for commercially
valuable genetic & biochemical properties.
• In simple terms this means the investigation of living things to see how they can be commercially useful to humans.
Important concepts:
• Bioprospection: is the process of discovey & commercialization of new product based on biological resources.
• Indigenous & traditional knowledge: if often helpful in bioprospecting & it is embedded in cultural traditions.
• Biopiracy: the commercial use of biological compounds by a country or organisation without obtaining consent
from or providing fair compensation to the peoples or nations in whose territory the materials were discovered.

22. Bioprospecting: A tool for survival & a
source of inspiration & innovation:
A. Traditional bioprospecting:
In 1991 a 5300 year old mummy was discovered in the Tyrolead Alps.
B. Modern bioprospecting:
Biodiversity offers three fundamental sources of inspiration to themodern scientist: chemicals, genes, &
designs.
1. Chemical prospecting:
• Drug & pharmaceuticals.
• Pesticides
• Cosmetics
• Food additives
• Other industrially valuable chemical products

23. Cont:
2. Gene prospecting:
• Genetic
• Engineering
• Crop development
• Fermentation
• Cell culture
3. Bionic prospecting:
• Designs
• Sensor
• Technologies
• Architecture
• Bioengineering
• Bio- modelling

24. Process of bioprospecting:
• As a process, it generally consists of four phases:
• Phase 1: on-site collection of samples.
• Phase 2: isolation, charactisation & culture of specific compounds.
• Phase3: screening for potential uses, such as pharmaceutical or other uses &
• Phase4: product development & commercialisation, including patenting, trials, sales &
marketing.

25. Why is it needed?
 The underlying aim of bio prospecting is to find new resources & products from nature that can be
used by humans.
 Improving human health, through both medicine & better nutrition are key focal areas.
 It plays a dominant role in discovering leads for drug development, since existing/known
compounds for developing drugs for human use are limited.
 A study showed that between 1983 & 2003, almost two thirds of anti-cancer agents being
investigated as drug candidates were derived from natural products.
 Other related sectors, such as crop plant biotechnology, screen natural resources for useful traits,
such as disease resistance.

26. Role of ethnopharmacology in drug
evaluation:
 The observation, identification, description & experimental investigation of the ingredients & the effect of
indigenous drugs is a truly interdisciplinary field of reasrch.
 Ethnopharmacologic research is based on botany, pharmacology & chemistry, but other disciplines have made
vital contributions.we have recently defined ethnopharmacology as “the interdisciplinary scientific exploration
of biologically active agents traditionally employed or observed by man”.
 The objectives of ethnopharmacology are to rescue & document an important cultural heritage before it is lost, &
to investigate & evaluate the agents employed.
 Observations & descriptions of the use & effects of traditional remedies, botanical identification &
phytochemical studies, are all within the scope of ethnopharmacology.
 The first successful multidisciplinary attack on an ethnopharmacological problem was initiated by the French
naturalist, Leschenault de la tour in 1803.
 The identification of medicinal plants & other traditional drugs is of course a crucial point, & good
ethnopharmacological research can only be based on properly prepared voucher specimens, carefully
authenticated by experts.

27. Cont:
 When biologically active principles have been found, the finding must be interpreted in the light of
the traditional use.
 Most traditional drugs are administered as mixtures of many components, & with today’s
knowledge of the many possible interactions between drugs, & between food & drugs,
ethnopharmacological research must deal with this aspect too.
 Additives, synergistic, or antagonistic effects are all possible. Various admixtures have also been
shown to affect the bioavailability of pharmacologically active principles.

28. Reverse pharmacology:
 Definition:
- Reverse pharmacology is the science of interating documented clinical/experiential hits, into leads by
transdisciplinary exploratory studies & further developing these into drug candidates by experimental &
clinical research.
 Scope :
- The scope of reverse pharmacology is to understand the mechanism of action at multiple levels of
biological organization & to optimize safety, efficacy & acceptability of the leads in natural products, based
on relevant science.

29. Concept of reverse pharmacology:
 The traditional knowledge inspired reverse pharmacology relates to reversing the routine
‘laboratory to clinic’ progress of discovery pipeline to ‘clinics to laboratories’.
 Conventional NCE path
Molecule Mice Man
 Reverse pharmacology path
Man Mice Molecule
 In this process ‘safety’ remains the most important starting point & the efficacy becomes a
matter of validation.

30. Phases of reverse pharmacology:
 Reverse pharmacology is a trans discipline that is comprised of three phases:
1. Experiential phase:
- Includes robust documentation of clinical observations of the biodynamic effects of standardized
ayurvedic drugs by meticulous record keeping.
2. Exploratory studies:
- For tolerability, drug- interaction, dose-range finding in ambulant patients of defined subsets of the
disease & para- clinical studies in relevant in vitro & in vivo models to evaluate the target-activity.
3. Experimental studies:
- Basic & clinical, at several levels of biological organization, to identify & validate the reverse
pharmacological correlates of ayurvedic drug safety & efficacy.