Effects of Thymoquinone on Sperm Parameters, Apoptosis, Testosterone Level, and Oxidative Stress in a Mouse Model of D-Galactose-Induced Aging

The aging process is accompanied by low secretion of sex hormones and testicular apoptosis. The antioxidant properties of thymoquinone (TQ) may prevent the effects of aging. Therefore, in the present study, the effects of different doses of TQ were investigated on sperm parameters, testosterone level, apoptosis, and oxidative stress in a mouse model of D-galactose-induced aging. In this experimental study, 30 adult male mice were randomly divided into 5 groups. The control group did not receive any injections, while the D-galactose group received an intraperitoneal injection of 300 mg/kg of D-galactose for 42 days. The TQ1-TQ3 groups received intraperitoneal injections of 5, 2.5, and 1.25 mg/kg of TQ plus D-galactose, respectively for 14 days (from the 1st to the 14th day of the experiment). The morphometric analysis, testicular apoptosis examination, and sperm analysis were performed, and testosterone level, total antioxidant capacity, and malondialdehyde level were evaluated on day 42 of the experiment. Data were analyzed using SPSS. Administration of TQ in the TQ1 group caused a significant difference in sperm parameters, compared to the D-galactose group (P<0.05). The lowest amount of positive tunnel cells was related to 5 mg/kg of TQ and the highest to 2.5 mg/kg of TQ. There was no significant difference in the parameters of seminal vesicles, epididymis, prostate, and testis between the groups (P>0.05). The malondialdehyde level were decreased in the TQ1-TQ3 groups, compared to the D-galactose group (P<0.001). On the other hand, the total antioxidant capacity was increased significantly in the TQ1 group, compared to the D-galactose group (P<0.001). Administration of 5 mg of TQ for 14 days improved sperm quality and biochemical parameters, while reducing apoptotic cells of the testes in a mouse model of aging