Medicinal plants in traditional systems of
medicine and emerging plants of drug and pharmaceutical industries
Introduction
- The use of plants as medicine is as old an human civilization.
- The earliest record of use of medicinal plants for prevention
of diseased and cure of ailments can be traced in "Rigveda"
perhaps the oldest repository o fhumna knowledge having been
written between 4,500 and 1600 BC.
- In the 'Atherveda", which is a later production , the
use of plants as drug is more varied and it is the "Ayurveda"
which is considered as "Upveda" that the definite
properties of drugs and their uses have been given in more
details.
- To the early part of this century, there was a perceptible
change from herbal medicines to synthetic and coal-tar products
and one time it was thought that the chemical systesis would
completely replace the drugs of plant origin.
- There is no doubt that, with the development of many wonderful
drugs of plant origin and phenomenal growth of modern pharmaceutical
industry, the pace of growth and popularity of herbal medicine
have been considerable affected in recent past, but the indigenous
(traditional ) or folk medicines still remain alive as precious
cultural heritage in different civilization of the world and
herbal medicines continued to cater the medicinal needs of
the third world countries which are inhabitated by approximately
80% of the world's population.
- Moreover, there has been renewed interest in the herbal medicines
and apex body like WHO has recognized the potentialities of
traditional or folk medicines in the management and self reliance
of medicinal care system, and currently encourages, recommends
and promotes the inclusion of herbal drugs in "National
Health Care Pragrammes" because such drugs are easily
available at a price within the reach of a common man and
as such are time tested and thus considered to be much safer
than the modern synthetic drugs.
- India, in this regard has unique position in the world, where
a number of traditional systems of midicine Ayurveda, Siddha,
Unani, Homeopathy are practiced and utilized in the total
health care system of the country and all the these systems
are predominantly dependent upon medicinal plants.
Medicinal plants used in Traditional or Indigenous systems of medicine
- Traditional medicine is wide spread through out of the
world and it comprises those practices based on beliefs that
were inexistence, often for hundreds of years, before the
development and spread of modern scientific medicines and
which are strill in use to day.
- As its name implies, "It is the part of tradition of
each country of employees practices that have been handed
down from generation to generation. Its acceptance by a population
is largely conditioned by cultural factors and much of traditional
medicine, therefore may not be easily transferable from once
culture to another".
- An important feature of traditional therapy is the preference
of practitioner for compound prescriptions over single substance/drugs
as it is being held that some constituents are effective only
in the presence of others.
- This renders assessment of efficacy and eventually identification
of active principles as required in international standards
much more difficult than for simple preparation.
- In India earlier, the medicines used in indigenous systems
of medicines were generally prepared by the practicing by
themselves, but now this practice has been largely replaced
by the establishment of organized indigenous drug's industry.
- It is estimated that at present there are more than 46,000
licensed pharmacies in Indian systems of medicine and nearly
400,000 registered practitioners of Ayurveda, Siddha, Unani
medicine or Homeopathy. As far as the Ayurveda systems of
medicine is concerned, it does not rule out any substances
being used as potential source of medicine.
- Presently about 1,000 single drugs and 8000 compound formulations
of recognized merit are in vogue.
- In fact reliable data on availability in different regions
of country as well as supply and demand of medicinal plants
used in production has been estimated around 2,000 crores
and is expected to reach up to 4,000 crores by the year 2,000.
Herbal Crude Drugs
- In India most of the medicinal and aromatic plant or crude
drugs (roots,Stems,leaves, flowers,seeds,fruit,whole plants
etc.) are handled by the traditional herbal crude drugs dealers
commonly known as "Pansaris" in the North and "Pachamarunna
Kado" in the south, who sell crude drugs under Ayurvedic,
Unani or local names.
- They have go their own traditional suppliers who have been
supplying the crude drugs to them since ages.
- In the market, we do not often get genuine or standardized
crude drugs due to one or another reason. In large number
of cases botanically different plants are being sold and used
for the same Ayurvedic drug in different places.
- Some times different species of the same genus which are more
easily and cheaply available are used in the place of one
that has been prescribed in the literature. Further, there
are certain well known drugs about which confusion still prevails
with regards to their correct identity dur to the fact that
descriptions of the plants in Ayurvedic literature are meager
and vague.
- As a result of this confusion, different drugs are being sold
in different states under exactly the same name and even the
learned physicians (Vaidyas, Kaviraj, and Hakims can not say
with certainity which is the authentic specimen meant in the
old texts.
- Some examples may prove this point of view. "Brahmi"
a very important drugs in the Ayurvedic Material Medica of
India, has been employed as a nervine tonic, useful in insanity
and epilepsy from ancient times.
- The correct identity of this drug is not certain on account
of the fact that different plants are sold under the name
"Brahmi". In UP, most of the Ayurvedic physicians
regard Centella asiatica (Syn. Hydrocotyle asiatica) to be
"Brahmi" while physicians of Bengal consider Bacopa
monnieri (Syn. Herpestis monniera) as the real Brahmi of Ayurveda.
In North Gujarat and Saurastra, the entire species of Hydrocatyle
viz. H.Java
- nica and h.rotundifolia are also used in some part or the
other as "Brahmi" or Mandukparni". However,
Most of the Physician consider Bacopa monnieri as Brahmi and
centella asiatica as "Mandukuparni" being two separate
indentity of the drug in Ayurvedic texts.
- Similarly Chaerophyllum villosum sold in place of Aconitum
heterophyllum as "Atis"; Polyalthia Longifolia and
Shorea robusta inplace of Saraca asoca as "Ashoka",
and different crude drugs are available in the market under
one vermacular names of "Nag Keshar"-e.g Flowe buds
of Mesua ferrea, Ochrocarpus, logifolius, Callophyllums inophyllem,
Cinnamomum tamala and Dellenia Pentugyna etc.
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Global Importance
- If we are to discuss the global importance of medicinal
plants, it is necessary to defince the term medicinal plant.
- In the broadest definition of medicinal plants-It includes
all higher plants that have been alleged to have medicineal
properties i.e effects that relate to health or which have
been proven to be useful as drugs by western standards of
that which contain constituents that are used as drugs.
1. Complicating the matter of identifying all such plants
is that, there are no readily available souces of information,
i.e, the information is found scattered through out the world-
in classical old leteratures, books om medical botany, in
ethnbo-medico-botanical survey reports for specific geographic
regions and or for different in various herbiaria. In variety
of reviews articles and in other sources.
2. Secrets locked in minds of indigenous peoples, traditional
healers etc. are less likely to discovered.
Importance of medicinal plants
- Finally how does one measures "Importance" of
medicinal plants. It may be possible in two ways
1. It is possible to document in many ways, that medicinal
plants and their active principles are able to alleviate or
cure human suffering and illness.
2. Another, way is to measure the monetary value of the cost
of the plants entering into global commerce, but data are
available only for plants that are entering into commerce
on a major scale i.e. hundereds or thousands of tons per year.
3. On global basis, it appears that only consolidated source
of information in the monetary values of medicinal plant entering
into global commerce is that provided by the International
Trade Centre (UNCTAD/GATT). The most recent compilation of
data from this agency involving medicinal placts and their
derivatives was published in 1982. However this information
must be considered as grossly incomplete. Major data on export/import
of medicinal plants involve West Germany, Singapore and Hong
Kong. However, these countries produce little, medicinal plants.
4. Other producing countries often do not report details of specific
plants but only report figures for "Seeds", "Roots",
"Medicinal Plnats" etc. However, a publication.
Export potential of selected Medicinal plants and their derivatives
has been brought out in India by CHEMEXCIL India.
Prospects of cultivation
- Most of the medicinal plants extensively used in traditional
systems of medicines are obtained from wild sources leading
to dwindling of populations of numerous plants. Some of the
important medicinal plants have become threatened or endangered
in their natural habitats.
- Rauvolfia serpentina (Sarpgandha) a very important medicinal
plants of widespread distribution is today no where in abundance
because of heavy exploitation of the wild strain during the
last 60 years.
- Aconitum heterophyllum (Atish), A.deinorrhizum, Cochicum lutium
(Chlchicine plant) Gentiana Kurroa widely distributed in western
Himalayan have become endangered species. Commiphora wightii
(Guggul) distributed in Gujarat and Rajasthan has been much
exploited for gum resin.
- Podophyllum hexandrum (Babd kakari) and Nardostachys grandiflora
(Jatasmansi) now rarely occur in Himalay.
- Populations of Coptis teeta of Mismee hills (Arunachal Pradesh)
have seriously dwindled due to excessive trade from natural
population. The increasing demands of the pharmaceutical industry
have created problem of supply and one of the major difficulties
being experienced by the Indian systems of medicine is that
of obtaining sufficient qualtities of medicinal plants for
the manufacture of genuine medicines.
- In the absence of standards for crude drugs adulteration and
substitution have become rampant.
- To correct this situation, measures are needed to promote
the cultivation of medicinal plants, to improve method of
collection, to ensure effective quality control and to regulate
commerce so as to protect the producer and the consumer.
- In our country, there are only few herbal drugs under large
scale cultivation that are used in indigenous systems of medicines
as well as in modern systems of medicines. Theres are Isabgol
(Psyllium), Ahiphen (Poppy) and Svarnpatri (Senna).
- There are other that are cultivated on a very small scale
exclusively used in indigenous systems of medicine: Kali mirchi
(Pepper Nigrum), Haldi (Curcuma longa), Adraja (Zingiber officinalis),
Dhaniya (Coriandrrum); Sanuf (Foeniculum), Ajawayn (Trachyspernum)
etc. Cultivation of medicinal plants permits production of
uniform quality raw material whose properties are standardized
and from which the crude drugs can be obtained unadulterated.
Collection from wild Versus cultivation of medicinal plants
|
Collection
|
Cultivation
|
Availablity
|
Decreasing
|
Increasing
|
Fluctuation
of supply |
Unstable
|
More controlled and quality
|
Quality control |
Poor
|
High
|
Botanical indentification |
Sometimes not reliable
|
Not questionable
|
Genetic improvemt |
No
|
Yes
|
Agronomic manipulation |
No |
Yes |
Post harvest
handling |
Poor |
Usually good |
Adulteration |
Likely |
Relatively safe |
- One of the major difficulties for undertaking medicinal
plants in large scale is the lack of scientific and appropriate
agro technology for different climatic zones.
- Experimental cultivation has been carried out in several places,
but the recommended commercial practices had been neither
worked out nor tested on an industrial scale. Moreover, even
if the cultivation is likely to yield economic returns, the
dominant sector or cultivators in the country are conservative
and are reluctant to abandon their time tested crops and turn
to medicinal crops.
- In the view of the present status of medicinal plants used
in medicines, there is a need to pay special attention on
the cultivation of medicinal plants which are extensively
used by industry; which have become endangered/threatened;
on which significant research lands have been obtained and
are emerging in world pharmaceutical industry; which are being
imported and have exported potential.
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Products from Aromatic crops & their uses
Aromatic Crops
Distillation Water
1. Recycle for Distillation
2. Irritation
3. Spraying on Crops
4. Extraction of dissolved Oil components by Cohobation,
Poroplast technique etc.
Suggested Uses:
4. In Naturopathy
5. Aromatheraphy etc.
6. For bathing
7. Herbal Teas etc.
8. Making of perfumed Waters
Essential Oil (Steam Distillation)
Fractional Distillation
Terpeneless Essential Oils, Aroma chemicals, Residual Essential Oils
1. Fragrance Industry
2. Flavour Industry
3. Pharmaceutial Industry
4. Other specialised used
Distilled Waste
1. Manure after composting
2. Mulching in crops
3. Fuel for Distillation Unit
4. Fodder for Domestic Animals
5. Manufacture of paper
6. Packing materials Manufacturing
Suggested Uses:
7. In Biogas Plant
8. Vermiculture
9. Mushroom culture
10. Agarbatti Industry
11. Extraction of specialized products of pectin from citru--rinds
12. Extraction of remaining oil components by Acid Hydrolysis
13. Blending with Fertilizers
14. In Insect repellin products
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Emerging medicinal plants for drugs and pharmaceutical industries
- The role of plants as a raw materials for isolation and
characterization of new drugs molecules for cure or prevention
of most dreaded diseases like cancer and AIDS, ahs created-resugence
of interest in them, all over the world.
- A recent study carried out indicates that about 60% of the
anti-tumour or anti-infective agents that are commercially
available or at the advanced stages of clinical trials are
of natural origin.
- At present, there are about 125-130 clinically useful prescription
drugs derived from about 100 species of higher plants. It
has also been estimated that about 5000 species of higher
plants worldwide have been studied in some details as possible
source of new drugs.
- A programme for the screening of plant extracts for a wide
range of biological activities is in progress at Central Drug
Research Institute. Lucknow (India) since last 25 years. So
far more that 3,300 plant materials have been screened for
various biological activities.
- Realizing, the importance of the plants in the druf discovery,
the bioprespection of the plant species is in progress in
many laboratories throughout the world, for the discovery
of new pharmaceuticals for the health problems such as drug
resistant infectious diseases, diabetes, asthma, arthristis
and neurological and psychiatric disordes.
- The satisfactory cure or means of management for many of such
diseases are not yet available in medical sciences.
Medicinal plants and phytopharmaceuticals
- The World Pharmaceuticals Industry is unique, extremely
competitive and highly research based. It is characterized
by some very special and striking features like high rate
of obsolescence of drug and technologies; requirements of
high quality of products;
- Good manufacturing practices(GMP), Good Labaratory praces
(GLP), environmental and regulatory requirements etc. The
pharmaceutical research on a established parameters is a complex,
multidisciplinary and time consuming activity. The current
estimate indicates that more that 12 years of research efforts
from discovery to marketing with average cost of about 250
US$ are required for a drug molecule to be used as therapeutic
agent.
- During the past decades, bulk production of placnt based has
become an important segment of India Pharmaceutical industry.
- Some of the phytopharmaceuticals whichare produced in India
at present include: morphine, codeine, papaverine (Papaver
somniferum), Quinine, Quinidine, Cinchonine and Cinchonidine
(Chichona spp. Viz: C.calisaya, C.ledgeriana,C.officinalis
and C.succirubra): Hyoscine and Hyoscyamine ((Hyoscyamus niger
and H.muticus); Colchine (Gloriso superba, Colchicum luteum
and Iphigenia stellata): Cephaeline and emetin (Cephalis ipecacuanha):
Sennoside A&B (Cassia angustifolia and C. acutifolia):
Rescephine, Rescinnamine, Ajmaline and Ajamalicine (Rauvolfia
serpentina): Vinblastine and vincristine, ajalmalcine, raubacine
(Catharanthus roseus):Guggal-lipid (Commiphora wightii), Taxol
(Taxus baccata); Artemisinin(Artemisia annua) etc.
- In the present time, Pharmaceutical and chemical sciences
have greatly contributed in the enhancement of the utility
of medicinal plants.
- Selected medicinal plants have been subjected to rigorous
chemical analysis and the bioactive compounds have been isolated
and variously evaluated.
- As a result, new drugs have been discovered and new applications
have been found for the compounds/medicines that were already
in use.
- Over the years, there have been four principal routes bywhich
have led to new therpeutic agents.
1. Chemical constituents isolated from the plants are directly
used as therapeutic agents Such as digitaxin, strophanhin,
morphine and atropine etc. which still unsurpassed in theie
respective filed.
2. Plant constituents which are used as starting material for
the synthesis of useful drugs. For example adrenal cortex
and other steroid harmones are generally synthesized from
plant steroidal sapagenins.
3. Natural products which serve as models for pharmacologically
active compounds in the field of drug synthesis.Frequently,
the side effects of a natural product often prevent its use
in medicine and resolved only by preparation of synthetic
derivative for example cocain which led to the development
of modern local anaesthetics; modification of colchicines
and of podophyllotoxin to obtain anti tumour preparation.
4. The plant constituents which demostrate a mode of action which
is then copied as in muscle relaxants from curare
- In recent years, there has been use of plant constituents
as research chemical particularly in the areas of molecular
biology. More that 50 anti-cancer drugs are not marketed because
of the side effects but they are widely used in research.
- One of the major criterion for selection of the plant for
discovery of new lead molecules is the utilization of available
knowledge in coded or un coded from in traditional or indigenous
systems or medicines, including folk or tribal medicines.
The past experiences in the areas of drug discovery have proved
that the success rates are very high with such plants and
they provide a fertile hunting ground for search of new therapeutic
agents.
- In this context, the development of new drugs, viz Reserpine
and related alkaloids for treatment of essential hypertension
and in certain neuro-psychiatric disorders from Rauvolfia
serpentina (Serpengandha); Guggulipid - for lowering of cholesterol
from Commiphora wightii Guggul); Forskolin (Coleonol) as anlihypertensive
agents from Coleus forskohlii; Bacosides - for memory enhancer
from Bacopa monnieri (Brohmi); are some of interesting example
of how obervation is recorded in ancient medical text of Ayurveda
or fold medicine, when investigated by modern scientific method
led to the successful development of new drugs and also provided
a lead compound for further modifications.
Some traditional Medicinal Plants on whcih Significant Research Leads
have been obtained and have yielded clinically useful drugs
Species
|
Common names
|
Drugs
|
Action / Clinical Use
|
1. Acorus calamus
|
Vacha |
Asarone |
Tranquilizer |
2. Adhatoda
vasica |
Vasa |
Vasicine (Pegarine) |
Oxytocic |
3. Andrographis
paniculata |
Kalmegh |
Andrographolide;
Neo-andrographolide |
Bacillary dysentery |
4. Asparagus
racemosus |
Satawar |
Sapogenin glycosides |
Anti-oxytocic,
anti-ulcerogenic, burns and wound healing |
5. Azadirachto
indica |
Neem |
Azadirachtin
oil |
Insecticide,
antifertility Antidiabetic |
6. Bacopa monnieri |
Brahmi |
Azadirachtin
oil |
Antianxiety
agent, Improve intellect, Adaptogenc |
7. Carica papaya |
Papaya |
Chymopapain |
Proteolytic,
mucolytic |
8. Centella
asiatica |
Brahmi |
Asiaticoside |
Vulenerary Wound
healing |
9. Cissampelos
pareira |
Patha |
Cissmpeline |
Skeletal muscle
relaxant |
10. Coscinium
fenestratum |
Daruhaldi |
Alkalods (Berberine) |
Cholera and
gastroentiritis |
11. Curcuma
longa |
Haldi |
Curceemin |
Choleretic |
12. Gloriosa
superba |
Kalihari |
Colchicine,
Thio- |
Odema |
13. Gossypium
spp. |
Kapa, cotton |
Gossypol colchicoside |
Male contraceptive |
14. Mappia foetida |
Chaneru |
Camptothecein |
Anticancer |
15. Mucuna pruriens |
Kewanchh |
L-dopa |
Antiparkinsonism |
16. Picrorhiza
Kurroa |
Kutki |
Glycosides |
Antihepatotoxic |
17. Phyllanthus
amarus |
Bhumyamlki |
Lingnans |
Antihepatotoxic
(Hepatitis B-virus) |
18. Silybum
marianum |
|
Silmarin |
Antihepatotoxic |
19. Taxus bacccata |
Talishpatra |
Taxol |
Anticancer |
20. Tephrasia
purpurea |
Sarpunkha |
Flavonoids,
alkaloids |
Viral hepatitis |
21. Urginia
indica |
Indian squill |
Scillarin A
& B |
Cardiotonic |
22. valeriana
wallichii |
Tagar |
Valeopotrates |
Sedative |
- Besides this the plant species viz: Canarium euphyllum,
C.manii (Collected from Andman forests): Paeonia obovato (Collected
from western ghats); are found to be very active against rhematoid
arthritis and inflammation.
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