Protective effect of Nigella sativa seeds against carbon tetrachloride-induced liver damage.

It has been reported that Nigella sativa oil possesses hepatoprotective effects in some models of liver toxicity. However, it is N. sativa seeds that are used in the treatment of liver ailments in folk medicine rather than its oil. Therefore, the aim of this study was to investigate the effect of the aqueous suspension of N. sativa on carbon tetrachloride (CCL4)-induced liver damage. Aqueous suspension of the seeds was given orally at two dose levels (250 mg/kg and 500 mg/kg) for five days. CCL4 (250 microl/kg intraperitoneally / day in olive oil) was given to the experimental group on days 4 and 5, while the control group was only treated with the vehicles. Animals treated with CCL4 showed remarkable centrilobular fatty changes and moderate inflammatory infiltrate in the form of neutrophil and mononuclear cells when compared to the controls. This effect was significantly decreased in animals pretreated with N. sativa. Histopathological or biochemical changes were not evident following administration of N. sativa alone. Serum levels of aspartic transaminase (AST), and L-alanine aminotransferase (ALT) were slightly decreased while lactate dehydrogenase (LDH) was significantly increased in animals treated with CCL4 when compared to the control group. LDH was restored to normal but ALT and AST levels were increased in animals pretreated with N. sativa. In conclusion, N. sativa seeds appeared to be safe and possibly protective against CCL4-induced hepatotoxicity. However, further studies may still be needed prior to supporting its use in folk medicine for hepatic diseases.