Immunomodulatory Compounds From Medicinal Plants As Potential Prophylactic/ Therapeutic Drugs.


Shakti N. Upadhyay


Symposium 'State-of-the-Art Strategies and Technologies for Conservation of Medicinal and Aromatic Plants' held under the auspices of G-15 Gene Banks for Medicinal and Aromatic Plants, Kuala Lumpur Malaysia.




Medicinal plants, immunomodulation, immunotherapy


It is now being recognized that immunomodulation could provide an alternative to conventional chemotherapy for a variety of diseased conditions. This concept relates to "educating" or "activating" the immune system to react against and kill the pathogens / tumor cells. The advantage of this therapeutic strategy is that the immune system is selective and it normally attacks only diseased / infected or tumor cells, ignoring the normal healthy ones. This is in contrast to chemotherapy that uses anti-biotic / antitumor drugs which directly act upon the pathogen / tumor cells and often kill all dividing cells without discrimination. On the other hand, in some situations the diseases are caused due to inflammatory response or sensitization of the immune system to self molecules as in autoimmune diseases. In such situations the immune respojgse needs to be controlled or even suppressed. Medicinal plants used in the traditional systems of medicine are the potential source of such immunomodulatory compounds. Based on this concept, the work carried out at National Institute of Immunology has lead to isolation and identification of an immunostimulating compound, NII-30, from Piper longum, which has shown therapeutic effect against tumor in experimental animals. Similarly another compound, NII-78, isolated from Mangifera indica, has been found to activate the macrophages and induce intracellular killing of parasites. On the other hand, NII-60, isolated from Berberis aristata, has been found to have immunosuppresive effects. The immunosuppressive potential of this compound can be exploited for treatment of auto-immune diseases like rheumatoid arthritis or in a situation like rejection of organ transplants and also for prevention of septic shock in surgical/ burn cases. While the pure compounds, isolated from the plant materials, can be further developed as modern drugs, it is also possible to develop standardized herbal drugs from these plant materials using the immunological tests for efficacy and the purified compounds as chemical markers for quality control.