EFFECT OF ASOKA ON THE INTRACELLULAR GLUTATHIONE LEVELS AND SKIN TUMOR PROMOTION IN MICE

The bark of Saraka asoca (asoka) is commonly used to treat various dis eases by the Indian system of medicine and in Sri Lanka. Further purif ication and chemical analysis of the active compound from the bark ext ract of asoka showed that (-)-epicatechin was responsible for the obse rved antitumour/anticarcinogenic activity. Papilloma formation in mice initiated with 7,12-dimethylbenz[a]anthracene (DMBA) and promoted usi ng croton oil was inhibited by the topical application of 100 mg/kg bo dy weight (b.w.) of (-)-epicatechin isolated from asoka bark extract. Oral administration of the same dose restricted the growth of s.c. inj ected 20 methylcholanthrene (MCA) induced soil tissue fibrosarcomas si gnificantly in mice. Elevations of almost 2-4-fold in the intracellula r reduced glutathione and related enzymes viz., glutathione reductase and glutathione S-transferase of sarcoma-180 tumour cells were noted i n the presence of 1 mug/ml of (-)-epicatechin, further highlighting it s antiproliferative effect.