RT Journal Article SR Electronic T1 Effect of an Extract of Withania somnifera Root on Estrogen Receptor-positive Mammary Carcinomas JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 1519 OP 1523 VO 33 IS 4 A1 KAMEL F. KHAZAL A1 TEMESGEN SAMUEL A1 DONALD L. HILL A1 CLINTON J. GRUBBS YR 2013 UL http://ar.iiarjournals.org/content/33/4/1519.abstract AB The chemopreventive activity of an extract of Withania somnifera (WS) roots was examined in female Sprague-Dawley rats that received the mammary carcinogen methylnitrosourea (MNU). The dose of the extract, administered by gavage, was 150 mg/kg body weight daily for 155 days, after injection of MNU. Rats in the treated group (N=15) had an average of 3.47 tumors, and rats in the control group (N=15) had 4.53, a reduction of 23%. The average weights of tumors were 4.98 g for rats in the treated group and 6.30 g for the controls, a difference of 21%. Labeling indices for Ki67 and proliferating cell nuclear antigen (PCNA) markers in cancers of the treated group were 42% and 38% lower, respectively, than those of the corresponding indices for the control group. These results indicate that the root extract significantly reduced the rate of cell division in the mammary tumors.