Hepatoprotective activity of Phyllanthus amarus Schum. et. Thonn. extract in ethanol treated rats: in vitro and in vivo studies.

The present study was undertaken to investigate the protective effect and possible mechanism of aqueous extract from Phyllanthus amarus Schum. et. Thonn. (PA) on ethanol-induced rat hepatic injury. In the in vitro study, PA (1-4 mg/ml) increased %MTT reduction assay and decreased the release of transaminases (AST and ALT) in rat primary cultured hepatocytes being treated with ethanol. Hepatotoxic parameters studied in vivo included serum transaminases (AST and ALT), serum triglyceride (STG), hepatic triglyceride (HTG), tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta (IL-1beta), together with histopathological examination. In acute toxicity study, single dose of PA (25, 50 and 75 mg/kg, p.o.) or SL (silymarin, a reference hepatoprotective agent, 5 mg/kg), 24h before ethanol (5 g/kg, p.o.) lowered the ethanol-induced levels of transaminases (AST and/or ALT). The 75 mg/kg PA dose gave the best result similar to SL. Treatment of rats with PA (75 mg/(kg day), p.o.) or SL (5 g/(kg day), p.o.) for 7 days after 21 days with ethanol (4 g/(kg day), p.o.) enhanced liver cell recovery by bringing the levels of AST, ALT, HTG and TNF-alpha back to normal. Histopathological observations confirmed the beneficial roles of PA and SL against ethanol-induced liver injury in rats. Possible mechanism may involve their antioxidant activity.