Growth inhibition of human tumor cell lines by withanolides from Withania somnifera leaves Bolleddula Jayaprakasam, Yanjun Zhang, Navindra P. Seeram, Muraleedharan G. Nair * Bioactive Natural Products and Phytoceuticals, Department of Horticulture and National Food Safety and Toxicology Center, Michigan State University, East Lansing, MI 48824, USA Received 9 May 2003; accepted 7 July 2003 Abstract 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. 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)-h-D-glucopyranosyl- (1 ! 4)-h-D-glucopyranoside (6), 27-O-h-D-glucopyranosylphysagulin D (7), physagulin D (8), withanoside IV (9), and 27-O-h-D-glucopyranosylviscosalactone B (10), 4, 16-dihydroxy-5h,6h-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 (IC 50 ) 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 F 0.01 to 11.6 F 1.9 Ag/mL. Viscosalactone B (12) showed the 50% inhibition at concentrations ranging from 0.32 F 0.05 to 0.47 F 0.15 Ag/mL whereas its 27-O-glucoside derivative (10) exhibited IC 50 between 7.9 F 2.9 and 17.3 F 3.9 Ag/ml. However, Physagulin D type withanolides showed either weak or no activity at 30 Ag/mL. Therefore, incorporation of withanolides in the diet may prevent or decrease the growth of tumors in human. D 2003 Elsevier Inc. All rights reserved. Keywords: Withania somnifera; Withanolides; Medicinal Plant; Lung; Colon; CNS; Breast cancer 0024-3205/$ - see front matter D 2003 Elsevier Inc. All rights reserved. doi:10.1016/j.lfs.2003.07.007 * Corresponding author. Tel.: +1-517-353 2915; fax: +1-517-432 2310. E-mail address: nairm@msu.edu (M.G. Nair). www.elsevier.com/locate/lifescie Life Sciences 74 (2003) 125 – 132