Improvement in renal biochemical and hematological alterations and oxidative stress following use of sildenafil in streptozotocin-induced diabetic rats

Introduction: Diabetes mellitus is a chronic metabolic disease marked by persistent hyperglycemia. It is associated with oxidative stress and the dysfunction, long-term damage, and failure of different organs. The aim of the present study is to evaluate the effects of sildenafil (Sild) on serum biochemical and hematological alterations and oxidative stress status in the kidneys of rats with streptozotocin (STZ)-induced diabetes.
Materials and methods: In this experimental study, fifty male Wistar rats were separated into the following four groups (n=10/group): i. control (Ia), ii. Sild-treated control (Ib), (n=15/group): iii. diabetic (IIa), and iv. Sild-treated diabetic (IIb). Diabetes induction was carried out through a single intraperitoneal (IP) injection of STZ (50 mg/kg). Sild (20 mg/kg body weight [BW]) was given orally for six weeks. Blood samples were used to determine levels of fasting blood glucose (FBG), glycated hemoglobin (HbA1c), alanine aminotransferase (ALT), urea, creatinine, prothrombin time (PT), partial thromboplastin time (APTT), fibrinogen, protein C, and protein S. The antioxidant status was evaluated by determining the levels of malondialdehyde (MDA) and catalase (CAT) in the kidneys. Data were analyzed by one-way analysis of variance (ANOVA) with P<0.05 as the significance level.
Results: FBG, HbA1c, AST, urea, creatinine, and MDA were significantly higher in the diabetic groups compared to the controls. No significant difference was seen in PT of control and diabetic rats, whereas APTT was significantly lower in diabetic rats than control animals. On the other hand, fibrinogen was significantly higher in diabetic rats than in normal controls. Treating the diabetic rats with Sild brought the changes in the above parameters back to normal levels (P<0.05). In addition, Sild significantly improved low levels of CAT as well as high levels of MDA in the kidney (P<0.05).
Conclusion: Sild showed beneficial effects and improved oxidative damage induced by STZ in the kidneys of rats; therefore, it may be considered as an effective treatment for minimizing diabetic complications.