The importance of medicinal plants in the treatment of a variety of human ailments man has been dependent on the higher plants as a source of food and medicine.
2. The importance of medicinal plants in the treatment of a variety of
human ailments man has been dependent on the higher plants as a
source of food and medicine.
Today's modern age of advancement in instrumentation technology,
sophisticated techniques like nuclear magnetic resonance (NMR)
spectroscopy and mass spectroscopy have markedly reduced the time
and effort required for structural determination.
The development of science of phytopharmaceuticals and hopes for
remedies in chronic diseases generated new enthusiams in the
research workers to develop herbal medicine.
3. The concept of drug design of some of the synthetic molecules has
emerged out of their quantitative structure activity relationship (QSAR).
Example: belladona alkaloids, quinine, physostigmine, cocaine, opiates,
codeine and salicylic acid have served as models for design and
synthesis of anti-cholinergics, anti-malarial, ant-cholinesterases.
During this period since 1959, about 50,000 plant extracts have been
screened under the auspices, of national institutes of health in the USA .
4. The growing concern in the recent past over the toxic effect of
various synthetics drugs has forced the researches, academicians
and doctors to consider some steps of preventing the misuse of
such drugs.
The occurrence of side effects after a long term use of synthetic
drugs is always feared during the treatment of chronic diseases.
List of phytopharmaceuticals, reveals that majority of them are
derived from phylum spermatophyta .
5. Some useful oils, resins and the alkaloid ephedrine are obtained from
the species gymnospermae, whereas the division angiospermae, which
is divided into monocotyledons and dicotyledons, provides a variety
of useful drugs.
The algae are a source of a limited number of drugs such as agar and
alginic acids.
6. PHYTOPHARMACEUTICALS OF
COMMERCIAL SIGNIFICANCE
The crude drugs are subjected to a suitable method of extraction and
purification for the isolation of phytopharmaceuticals, which could be
incorporated as active ingredients in the modern system of medicine.
1. The anthracene glycosides such as sennosides are extracted in the from
of their stable calcium salts from the leaves and pods of senna.
2. The indole alkaloids such as ergometrine and ergotamine are
commercially extracted as their salts from the fungus of ergot, known as
Claviceps purpurea.
3. Caffeine is exctrated from tea or teawaste, where as nuxvomica seeds
serve as the raw material for the extraction of strychnine.
7. 4. The antihypertensive and tranquilising agent reserpine is
commercially obtained from the roots and rhizomes of Rauwolfia
serpentina.
5. Other tropane alkaloids l-hyoscyamine and atropine are obtained
form Atropa belladona and Datura metal .
6. Isoquinoline alkaloids such as morphine, papaverine, codeine and
thebaine are extracted from opium, latex obtained from poppy
capsules.
7. The alkaloids quinine and quinidine are commercially obtained
from the bark of different cinchona species.
8. pilocarpine nitrate, a life saving drug useful in treatment of
glaucoma, is extracted from leaves of Pilocarpus jaborandi.
8. 9. A number of essential oils and their chemicals used as medicinal and
flavouring agent are obtained from plants sources. Examples volatile oils of
peppermint, spearmint, clove, eucalyptus, ginger, citronella, thyme and vetiver.
10. Citral from lemon grass oil, is itself used in perfumery and soaps .
11. Spices are usually more diversified than the perfume principles containing
not only terpenes, from dill, caraway, fennel, celery etc.
But also aromatic aldehydes, phenols and sulphur compunds. s
9. 12. Etoposide is a new semi-synthetic antineoplastic agents derived from
subterranean parts of podophyllum peltatum reported to be useful in
chemotherapeutic treatment of refractory testiculur carcinomas, small cell
lung carcinomas, non-Hodgkin’s lymphomas .
13. Guggulipids with antiarthrytic property from commiphora mukul; ellagic
acid as a prototype anti-mutagen and cancer preventing agent; vasicin as
oxytocic agent from Adhatoda vasica.
10. CURRENT TREND OF MARKET IN
MEDICINAL PLANTS
The trade in plant products has increased following their increased
use in the food and cosmetic industries.
The value of total imports of medicinal plants has increased from 355
million US dollars in 1976 to 551 million US dollars in 1980.
Japan is a major importer of medicinal plant among the asian
countries.
11. Cinchona bark and alkaloids, liquorice root and extract, papain, digitalis,
gingseng and laxatives have large to medium sales volumes in
industrialized countries.
The major exporter of psyllium and sandal wood oil and opium alkaloids
in India.
In last two decades, the scientific community as shown a fast increasing
in pharmacognosy and natural products research.
In the new promising era of pharmacognosy, there are three major areas
of studies which include:
a) Studies of new biologically active natural products,
b) quality control of natural drugs
c) Production of drugs from natural sources especially by biotechnological
ways.