Diabetes mellitus (DM) is a complex metabolic disease and it is also closely associated with a reduction in fertility in male patients. The purpose of the present study was to investigate the antidiabetic effect of carvacrol (CRV), as a potent antioxidant, on the numbers of germ cells and Sertoli cells in testicular tissue, and the messenger RNA (mRNA) and protein expression of some genes involved in spermatogenesis, including luteinizing hormone/choriogonadotropin receptor ( LHCGR), follicle-stimulating hormone receptor ( FSHR), and steroidogenic factor 1 ( SF-1), as well as hormones such as luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), and insulin. Adult male Wistar rats ( n = 32) were randomly divided into four groups (eight animals per group), including healthy control that received 0.2% Tween 80, diabetic control group, the diabetic group treated orally with CRV (75 mg/kg), and CRV group that received orally CRV (75 mg/kg). The duration of the treatment period lasted 8 weeks. In the diabetic group, the numbers of Sertoli cells and germ cells were significantly decreased, while the treatment with CRV prevented the degree of the damage to the cells mentioned earlier. CRV administration elevated the concentrations of insulin, T, FSH, and LH. Moreover, treatment with CRV significantly enhanced the levels of the mRNA and protein expression of SF-1, LHCGR, and FSHR. According to the obtained results, CRV administration could prevent the deleterious effects of DM on testicular germ cells, and it increases the levels of hormones and some essential genes, such as SF-1, LHCGR, and FSHR, involved in the process of spermatogenesis.
Follicle-stimulating hormone increases the turnover of G-protein alpha i-1- and alpha i-2-subunit messenger RNA in Sertoli cells by a mechanism that is independent of protein synthesis.