The Effect of Silymarin on the Expression of Urotensin–II and Urotensin–II Receptor Genes in the Liver Tissue of Type 2 Diabetic Rats

Studies have shown that the increase in urotensin – II is associated with diabetes disorders. Considering that using herbal medicines for the treatment of diseases leads to fewer complications compared to most chemical drugs, the present study was conducted to investigate the effect of silymarin on glucose, and insulin levels and the expression of urotensin – II (U–II) and urotensin – II receptor (U–II R) genes in the liver tissue of type 2 diabetic male rats. In this experimental study, 36 male albino Wistar rats were randomly divided into 6 groups (n=6): 1. Control group; 2 and 3. Control groups treated with 60 and 120 mg / kg / day silymarin; 4. Type 2 diabetic group which received an intraperitoneal (i.p.) injection of 60 mg / kg streptozotocin and 120 mg / kg nicotinamide; 5 and 6. Diabetic rats treated with 60 and 120 mg/kg/day silymarin. After 60 days of treatment, serum and liver tissue samples were collected. Glucose, insulin, HOMA-IR index and liver enzymes were evaluated by spectrophotometry and ELISA methods, while gene expression in liver tissue was analyzed by Real-time PCR method. Insulin levels increased significantly in diabetic groups treated with silymarin (60 and 120 mg/kg) (9.6±1.11 and 9.8±0.96, respectively) in comparison with the diabetic control group (7.10±1.06) (p<0.05). Moreover, glucose level, HOMA-IR, liver enzymes, U–II and U – II R expression in diabetic group treated with silymarin significantly decreased compared to diabetic control group (p<0.05).   The results of this study showed that administration of silymarin improves liver function in diabetic rats.