Toxicological assessment on extracts of Phyllanthus amarus Schum and Thonn

Phyllanthus amarus is used in traditional medicine to treat diabetes. The purpose of this study is to evaluate its toxicity. The cytotoxicity of its aqueous extracts (AE) and hydroalcoholic extracts (HAE) on Caco-2 cells was evaluated using neutral red uptake and MTT test. Aqueous extract was more cytotoxic than hydroalcoholic extract (IC50 being 89.6 µg/ml versus 277 µg/ml). Acute and sub acute toxicity of the extracts were evaluated respectively in Swiss mice and Wistar rats. A single oral dose of the extracts at 5 g/kg b.w. did not produce mortality or any significant change in treated animals over a 14 day observation period. In the sub acute toxicity study, extracts were administrated (1 and 3 g/kg b.w.) daily by gavage to rats for 28 days. No significant differences were observed in body weight gain and blood glucose levels between controls and treated groups. Clinical biochemistry revealed no toxic effect. Neither gross abnormalities nor histopathological changes in liver, kidney and pancreas were observed. Extracts of P. amarus could then be considered to be safe in animals by oral route (LD 50 > 5 g/kg) even though it is slightly cytotoxic to the human adenocarcinoma cell line Caco-2.