Withania somnifera (WS) has a wide range of therapeutic applications for several disorders. Toxicity studies on WS are very limited. The purpose of the present work is to study the acute and sub-chronic toxicity of WS extracts in rats and to determine the LD50 value, which helps in determining the safe dose range for the plant extract to be used with no harmful or lethal effects on the animal. Rats in the acute study were IP injected with the alcoholic extract of WS (the arial parts) at doses of (0), 150, 300, 600 and 1200 mg/kg bwt. In sub-chronic toxicity study, WS extract was administered IP at a dose of 10%, 20% and 40% of the obtained LD50 (52 mg/kg bwt, 104 mg/kg bwt and 208 mg/kg bwt respectively) for 60 days. Acute toxicity revealed an IP LD50 of 522 mg/kg wt. Significant changes in body weight, hematological, biochemical and histopathological were recorded in 20% and 40% LD50 groups with 15 – 40 % mortalities respectively, by the end of the experiments. Based on this study, WS showed toxicity at doses higher than 10% LD50 when given IP and it was recommended to use â‰¤ 10% LD50 (IP) doses of WS extracts, than the tested here to start within setup protection or treatment studies.
Keywords: Withania somnifera, lethal dose fifty, sub-chronic toxicity, albino rats.