The protective effect of Stevia rebaudiana Bertoni on serum hormone levels, key steroidogenesis enzymes, and testicular damage in testes of diabetic rats.

Diabetes Mellitus (DM) is a kind of metabolic endocrine diseases, which has various effects on the gonadal system. The current study aimed to examine the effect of Stevia rebaudiana Bertoni extract on the mRNA expression involved in testosterone synthesis, and stereological parameters in rat testes, for improving diabetes complications. In this study, 48 rats were randomly classified into control, diabetic (streptozocin 60 mg/kg + nicotinamide 120 mg/kg), diabetic + Stevia (400 mg/kg), and diabetic + metformin (500 mg/kg) groups. Finally, Fasting Blood Sugar (FBS) level, the serum level of LH and testosterone, the Star, Cyp11a1, and Hsd17b3 gene expressions, and changes in the testis histology were evaluated. The results indicated a decrease in body weight, serum LH and testosterone level, the star gene expression, stereological changes of testes, and an increase in the FBS level in diabetic group, compared with the control group (P<0.05). Nonetheless, Stevia significantly reduced the FBS and increased the serum LH level, in comparison with diabetic rats (P<0.05), but no significant differences in the serum testosterone level and the Star gene expression has been found. Stevia also resulted in an increase in weight, testis volume, the number of sexual lineage cells, and sperm count and motility, compared to diabetic rats (P<0.05). Due to its antioxidant properties, Stevia enhanced the alteration in spermatogenesis and stereological characteristics in diabetic rat testes. Hence, Stevia could diminish the reproductive system problems and improve infertility in diabetic male rats.