The effect of Nigella sativa on the diabetic liver in male albino rats with a special focus on the role of hepatic oval cells

Background:Liver-related complications are a significant cause of death in diabetes and are often unrecognized. Aim of the work :This study was designed to evaluate the hepatoprotective properties of Nigella sativa (NS) in streptozotocin-induced diabetes in rats. Moreover, the effect of NS on hepatic oval cells in the liver of diabetic rats was determined. Materials and methods :Rats were divided into three groups: group I was the control group; group II included diabetic rats [single intraperitoneal injection of streptozotocin (50 mg/kg body weight)]; and group III included diabetic rats treated with NS (300 mg/kg/day, administered orally) for 4 weeks. Liver sections were subjected to H E, masson staining, and immunohistochemical staining of proliferating cell nuclear antigen, α-smooth muscle actin, and insulin protein. Plasma levels of aspartate aminotransferase, alanine aminotransferase, and albumin levels were measured. Liver hepatocyte growth factor gene expression was also measured by reverse transcription PCR. Results :Compared with the untreated diabetic group, NS preserved the hepatic architecture in diabetic rats as assessed histologically and biochemically. NS has a significant effect on liver regeneration as indicated by a significant increase in liver hepatocyte growth factor gene expression and a significant increase in proliferating cell nuclear antigen immunohistochemical staining. Hepatic fibrosis in diabetic rats was reduced by NS treatment as shown by the significant decrease in collagen deposition and α-smooth muscle actin immunohistochemical staining. Moreover, NS maintains functional insulin-producing hepatic oval cells as indicated by immunohistochemistry. Conclusion:This study showed the hepatoprotective effect of NS in experimentally induced diabetes in rats. NS also maintained functional insulin-producing hepatic oval cells in the liver of diabetic-treated rats.