The World Health Organisation (WHO) estimated that 80% of the populations of the developing countries roly on traditional medicines, mostly plant drugs, for their primary health care needs.

Medical plants as a group compromise approximately 8000 species and account for around 50% of all the higher flowering plant-species of India. The Indian systems of medicine have identified around 1500 medicinal plant, of which 500 species are mostly used in the preparation of indigenous formulations

The knowledge accumulates since time immemorial about the medicinal plants (herbs), which have been used as either “Rejuvenators” or “Healers” for the purpose of maintaining positive health or for the cure of different diseases was preserved in the old manuscripts. Everyday millions of people in the Third world are using herbal medicines because they believe in them.

It is know fact that India too has a tremendous wealth of medicinal plants. The Indian Materia Medica is more extensive than their counterparts from the Greeks, Romans, Egyptians, Babylonians, Persian,s Chinese and Arabians, In India westerner introduced modern system of medicine during British period. They brought their own Materia Medica and there was further amalgamation and use of new medicinal plants. However, they very fact that the indigenous system of india Ayurveda survies all trials and tribulations through centuries bears enough testimony to the efficacy of this Indian system, which is evident from the contributions made by western scientists like William Jones Fleming, Ainsile, Roxberg, Drury, Hooker, Warring, dymock.

Warden, Hooper and George Watt. Col. R. N. Chopra started a project at Calcutta School of Tropical Medicine and published a useful and informative volume on indigenous drugs of India.

Unfortunately, however, apart from sporadic attempts by a few reputed in investigators systematic efforts to explore and exploit this valuable potential has been lacking. Real progress in this field could only come through intensive inter-disciplinary work involving organic chemists, pharmacologists and clinicians practicing modern and indigenous system of medicine.

During the last three decades research on Indian herbs picked up momentum as the developed countries are evincing keen interest on safe and effective herbal medications for refractory conditions like Arthritis, Diabetes Asthma, Hypertensions, Obesity, Kidney Stones, peptic ulcer etc. the review of research carried out during 20th century and post independence period reveals that the herbs described in ayurvedic material Medica are possessing significant pharmacological actions as well as therapeutic value.

As for example:

Most of the Ayurvedic drugs are utilized in crude form. But the trends is changing. Reacting to this situations vyas committee has clearly stated “Quite often the ‘Aurvedic Research’ is used toadeater the analysis of Ayurvedic herbs and drugs, in modern laboratories, by those who explore the possibility of isolating some useful and active therapeutic agents for the purposes of enlarging the allopathic pharmacopoeia. It is also being applied to clinical trials of Ayurvedic drugs in the Allopathic hospitals, with a view to test their efficacy for rejection or acceptance thereof by the Allopathic doctors.

In the regional publication of WHO entitled "Herbal Medicine for Human Health" the author Dr. R.R. Chaudhury quotes that "even if the pharmacological activity resides in one plant, it is possible that there are two or three compounds in that plant extract which, together, induce the therapeutic activity. The ap- proach of extraction testing and further fractionation only de- crease the effectiveness of all fractions rather than concentrating all the activity. It has been shown that in approximately half of the plants the activity increases as further fractionation is carried out. However, in the other half, activity decreases as further frac- tionation is done. Scientists at half a dozen pharmaceutical houses have spent an enormous amount of fine and money trying to track down that is alkaloid, which is responsible for the blood sugar lowering or hypoglycaemic effect of a plant Momordica charantia. The fresh aqueous juice of this plant-the vegetable known as bitter ground-is being used by thousands of diabetic patients all over the world. Yet, all attempts to demonstrate in which one compound all this activity resides have failed because the activity in all fractions gets less and less instead of demon- strating enhanced activity in one extract or fraction. The full pharmacological effect will decrease or even disappear if further extraction and fractionation is carried out. Even at the state of laboratory and clinical testing, there are still other pitfalls which one must be aware of. It is now fairly well recognized that a medicinal plant may need to be administered with other sub- stances in order to exert its therapeutic effect. If three plants are given together with black pepper or jaggery or honey, it is pos- sible that every constituent in this combination has a specific effect. The second plant may be potentiating the effect of the first plant and the third plant may be preventing the toxicity of the second plant. The jaggery, honey or lack pepper may be re- leasing the activity of the first plant. In a situation such as this it would be futile to try and determine, by pharmacological screen- ing-in dogs or cats or rats-which plant actually possesses phar- macological activity. As we have seen, there may never be such plant acting alone. Even if the pharmacological activity resides in one plant, it is possible that there are two or three compounds in that plant extract, which, together, induce the therapeutic activity. The approach of extraction, testing and further frac- tionation, which has always been used, will not help. Further extraction and fractionation will only decrease the effectiveness of all fractions rather than concentrating all the activity.

The traditional approach of the following ten steps consists:

• Identification of the plant reportedly in use.
• Collection of the plant.
• Transport of the plant to the research laboratory.
• Storage.
• Preparation of extracts for testing.
• Administration of the extracts to animal models.
• Identification of the active or more active extract.
• Further fractionation of the active extract.
• Identification of the active principle chemical structure.
• Synthesis of the active substance.

Dr. U Ko Ko, Regional Director, WHO, expresses his views about whole drug administration as follows-modern science is founded on the belief that knowledge, as it progresses, accumulated new and improved concepts driving ot the old and the fallible. It prides itself on being objective ad rigorous, yet it fails to recognize that there can be other systems of thought. Phyto therapy ,or herbal medicine, believes in the harmonious view that “the whole plant is greater than the sum of its parts. “Some of the wonder drugs of modern medicine have their roots in indigenous medicine.