Rosemary leaf extract alleviates testicular impairment, oxidative stress, and apoptosis in streptozotocin-induced diabetic rats

Purpose: To investigate the protective effect of ethanol extract of rosemary leaf (EERL) (Rosmarinus officinalis L., family Lamiaceae) against testicular damage in streptozotocin (STZ) induced diabetes rats. Methods: The study involved four groups of rats (n = 6). Type 2 Diabetes (T2D) was induced by injection of 50 mg/kg of STZ. Group 1 served as the control (non-diabetic) group. Group 2 included T2D rats without treatment. Group 3 comprised T2D rats treated with EERL at 200 mg/kg. Group 4 consisted of T2D rats treated with EERL at a dose of 400 mg/kg. The extract was administered orally once a day for 4 weeks. Fasting blood glucose (FBG), serum testosterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), and oxidative stress markers (superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH), and glutathione peroxidase (GPx)) levels were assessed. Additionally, histopathological examination using H & E staining and immunohistochemical analysis was conducted to evaluate the expression of proliferating cell nuclear antigen (PCNA) and caspase-3 in the testes. Results: Compared to the untreated T2D rats, EERL administration at 200 mg/kg and 400 mg/kg produced a significant decrease (p < 0.05) in FBG levels and elevated levels of serum testosterone, FSH, and LH hormones (p < 0.05). Additionally, EERL administration (both doses) compared to the untreated T2D group led to a significant (p < 0.05) reduction in testicular MDA content and significant (p < 0.05) enhancement of GSH, SOD, and GPx. Moreover, EERL exhibited potential inhibition of STZinduced testicular damage and successfully averted apoptotic reactions by significantly reducing caspase-3 expression. Conclusion: Ethanol extract of rosemary leaf (EERL) diminishes testicular damage, and counteracts oxidative burden and apoptosis in T2D rats. Ethanol extract from rosemary may be a source of molecules for development as a medicine to support sexual hormones in individuals with diabetes.