Cytotoxicity and immunosuppressive activity of withanolides from Discopodium penninervium

The cytotoxicity and immunosuppressive activities of jaborosalactone-L and three 16 alpha-oxygenated withanolides from the leaves of Discopodium penninervium were studied. Jaborosalactone-L showed cytotoxicity only to the murine macrophage cell line, RAW 264.7, but the 16 alpha-oxygenated withanolides exhibited cytotoxicity to both human (COR-L23 and ECV 304) and murine (L929 and RAW 264.7) carcinoma cell lines with IC50 values ranging from 1.2-150 mu M. The non-toxic concentrations of these withanolides were also found to reduce the proliferative response of both inactive and E. coli lipopolysaccharide and concanavalin A activated rat spleen cells in vitro.