A study of the effect of Nigella sativa (Black seeds) in isoniazid (INH)-induced hepatotoxicity in rabbits

OBJECTIVE: To investigate the possibility of hepatoprotective effect of Nigella sativa (NS) in INH-induced hepatotoxicity. MATERIALS AND METHODS: The experiments were carried out on 24 male rabbits. They were divided into 4 groups (6 each); rabbits in group 1 were treated with INH following a standard protocol to induce hepatotoxicity. Rabbits in group 2 received starch. Group 3 received NS 1 g/kg/day before INH treatment. Group 4 rabbits were treated with NS only. Phenobarbital sodium (IP) was given to induce metabolism of INH. INH and NS were given orally. The experiment continued for 12 days; at day 13, animals were sacrificed. Liver function tests, malondialdehyde (MDA) were estimated in serum and in liver homogenates. Liver histopathological examinations were performed. RESULTS: Histopathological changes of hepatotoxicity were found in all INH-treated rabbits. The histopathological findings were normal in three rabbits treated with NS before INH, very mild in two, and with moderate changes in one rabbit. Serum alanine aminotransferase (S.ALT) was elevated after INH treatment and returned back to the control value when NS was given before INH. Similar pattern of effect was noticed with serum aspartate aminotransferase (S.AST), S. total bilirubin, S. MDA, and Serum alkaline phosphatase.In liver homogenate, AST, ALT, and MDA were increased with INH treatment compared to the control, then decreased with NS treatment given before INH CONCLUSIONS: NS has hepatoprotective effects against INH-induced hepatotoxicity in rabbits. NS 1 g/kg proved safe, no adverse effects; no histopathological or biological abnormalities were seen.