Protective effects of ethanolic extract of Nigella sativa seed in paracetamol induced acute hepatotoxicity in vivo.

Paracetamol overdose causes serious liver necrosis. Hepatoprotective activity of ethanolic extract of Nigella sativa in Paracetamol induced acute hepatotoxicity was investigated in rats. Fasted male Wistar rats were orally treated with Nigella sativa extract in graded doses for 5 days followed by Nigella sativa extract and paracetamol 3 g kg(-1) on 6 and 7th day. Circulatory liver markers and reduced glutathione (GSH) levels were estimated and histopathological study of liver performed. Paracetamol caused a significant increase in serum alkaline phosphatase, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and total Bilirubin and a significant decrease in GSH compared to control. Nigella sativa pretreatment significantly prevented the increase in liver enzymes and total bilirubin and decrease in GSH level as compared to paracetamol group. Liver histopathology showed marked reduction in sinusoidal dilatation, midzonal necrosis, portal triaditis and occasional apoptosis in Nigella sativa extract treated groups as compared to group receiving only paracetamol. Nigella sativa extract possesses hepatoprotective action against paracetamol induced acute hepatoxicity. Further research is needed to advocate its prophylactic use for drug induced hepatotoxicity.