Effects of Silymarin on Blood Glucose Concentration, Hepatic Histopathological Changes and FOXA2 and FOXA3 Gene Expression in Streptozotocin-Induced Diabetic Male Wistar Rats

Since the liver is among the primary organs susceptible to the effects of hyperglycaemia, diabetes mellitus (DM) could be a risk factor for the development and progression of liver damage. In present study, since no side-effects from the herbal medicine have been reported, the effect of silymarin on blood glucose concentration, hepatic histopathological changes and FOXA2 and FOXA3 gene expression, which are key genes in liver regeneration, was investigated. In this fundamental with experimental approach study, 40 male Wistar rats weighing 180-220 g were used. Rats were kept under the standard conditions of temperature of 20-22°C and humidity of 50% and consecutive 12-hour periods of light and darkness. Rats were randomly divided into five different groups (n=8 each), including healthy control rats, diabetic control rats, diabetic rats receiving silymarin (50, 100 and 150 mg/kg). Diabetes was induced by injecting streptozotocin (50 mg/kg B.W., i.p.). For 4 weeks silymarin groups received the drug once every three days through gavage and fasting blood glucose concentration measured once every 10 days. At the end of a month experiment, livers were harvested for hepatic histopathological and FOXA2 and FOXA3 gene expression changes analysis. In the diabetic rats treated with silymarin (50, 100 and 150 mg/kg), by comparison with the diabetic control group (p<0.05), glucose levels decreased significantly. Moreover, FOXA2 and FOXA3 expression in diabetic groups treated with silymarin significantly increased compared to diabetic control group (p<0.05). Hepatic histopathological changes were improved in the treated groups.The present study indicates that silymarin significantly decreased blood glucose concentration and increased the FOXA2 and FOXA3 gene products level. Hence, silymarin is able to improve some of the symptoms associated with diabetes and possesses hepatoprotective effects in streptozotocin-induced diabetic rats.