Materials and Methods: In this experimental study, 32 male Wistar rats aged 8 weeks and weighing between 200-250 g were randomly divided into four groups: a control group, a diabetic group, a diabetic group treated with 4 mg/kg of eugenol, and a control group receiving the same dose of eugenol. Diabetes was induced in the appropriate groups using a 50 mg/kg intraperitoneal (IP) dose of STZ. The treatment lasted for eight weeks, after which testicular tissue samples were collected.

Results: Histopathological analysis showed that eugenol treatment resulted in a notable decrease in testicular damage. The eugenol-treated group exhibited an elevation in the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) within the testicular tissue. The level of malondialdehyde (MDA) was significantly reduced in the eugenol-treated group. In terms of apoptosis, eugenol treatment led to decreased protein and mRNA expression of the pro-apoptotic protein BAX, a reduced BAX/BCL2 ratio, and decreased germ cell apoptosis (P < 0.01). Conversely, eugenol treatment increased the expression of the anti-apoptotic protein BCL2 at both the gene and protein levels.

Conclusions: The administration of eugenol has the potential to mitigate testicular tissue damage in diabetic rats due to its antioxidant and anti-apoptotic properties.