Ayurvedic medicines prepared in India consist of Withania somnifera roots as one of the main ingredients. It is consumed as a dietary supplement around the world. The leaves of W. somnifera were used in the treatment of tumors and inflammation in several Asian countries.
METHODS AND RESULTS:
We have isolated twelve withanolides such as withaferin A (1), sitoindoside IX (2), 4-(1-hydroxy-2, 2-dimethylcyclpropanone)-2, 3-dihydrowithaferin A (3), 2, 3-dihydrowithaferin A (4), 24, 25-dihydro-27-desoxywithaferin A (5), physagulin D (1-->6)-beta-D-glucopyranosyl- (1-->4)-beta-D-glucopyranoside (6), 27-O-beta-D-glucopyranosylphysagulin D (7), physagulin D (8), withanoside IV (9), and 27-O-beta-D-glucopyranosylviscosalactone B (10), 4, 16-dihydroxy-5beta, 6beta-epoxyphysagulin D (11), viscosalactone B (12) from the leaves of this species. Compounds 1-12 and diacetylwithaferin A (13) were tested for their antiproliferative activity on NCI-H460 (Lung), HCT-116 (Colon), SF-268 (Central Nervous System; CNS and MCF-7 (Breast) human tumor cell lines. The inhibitory concentration to afford 50% cell viability (IC50) for these compounds was determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Withaferin A and its derivatives exhibited inhibitory concentrations (50%) ranging from 0.24 +/- 0.01 to 11.6 +/- 1.9 microg/mL. Viscosalactone B (12) showed the 50% inhibition at concentrations ranging from 0.32 +/- 0.05 to 0.47 +/- 0.15 microg/mL whereas its 27-O-glucoside derivative (10) exhibited IC50 between 7.9 +/- 2.9 and 17.3 +/- 3.9 microg/ml. However, Physagulin D type withanolides showed either weak or no activity at 30 microg/mL.
CONCLUSIONS:
Therefore, incorporation of withanolides in the diet may prevent or decrease the growth of tumors in human. |