Diabetes-induced testicular oxidative stress, inflammation, and caspase-dependent apoptosis: the protective role of metformin

Context: Metformin's effect on glycaemic control is well documented, but its effect on diabetes-induced testicular impairment has been scarcely reported. Objective: To investigate the effects of metformin on testicular oxidative stress, inflammation, and apoptosis, which largely contribute to fertility decline in diabetic state. Methods: Male Sprague-Dawley rats were divided into 3 groups (n = 6/group) namely: normal control (NC), diabetic control (DC), and metformin (300 mg/kg b.w./d)-treated diabetic groups. Metformin was administrated for 4 weeks. Results: Decreased mRNA expressions and activities of antioxidant enzymes were seen in the testes of DC group. mRNA and protein expressions of pro-inflammatory and pro-apoptotic markers increased, while interleukin-10 and proliferating cell nuclear antigen (PCNA) decreased in the testes of DC group. Treatment with metformin up-regulated antioxidant enzymes, down-regulated inflammation, and apoptosis and increased PCNA immunoexpression in the testes. Conclusions: Metformin protects the testes from diabetes-induced impairment and may improve male reproductive health in diabetic state.