Synergistic amelioration of heat stress-induced testicular damage and impaired fertility by sesame seed oil and α-lipoic acid in male rats

Heat exposure affects spermatogenesis and causes testicular injury through oxidative stress mechanisms. This study examined the preventive benefits of sesame seed oil (SSO) and α-lipoic acid (ALA), both powerful antioxidants, against heat-induced testicular damage. Thirty male Wistar rats were allocated into five groups (n = 6 each): control (saline, no heat), heat stress (HS; 43 °C for 20 min/day for 60 days, saline), HS + ALA (100 mg/kg), HS + SSO (5 mL/kg), and HS + ALA + SSO. After 60 days, we examined the histology of the testicles, sperm parameters (concentration, motility, viability, morphology, and DNA integrity), oxidative stress markers, apoptotic gene expression, and fertility. These treatments enhanced sperm motility, viability, membrane integrity, and DNA stability while diminishing abnormalities. The levels of antioxidant enzymes (GPx, CAT, TAC, and SOD) and Bcl-2 increased, whereas the levels of pro-apoptotic markers (Bax and caspase-3/9), GSH depletion, MDA, and NO elevation decreased compared to those in the HS group (all p < 0.05). The SSO-ALA combination had synergistic effects, improving fertility parameters and alleviating histopathological damage. However, results may be confounded by experimental limitations such as anesthesia effects and lack of dose standardization. These results indicate that SSO and ALA may be effective treatments for heat stress-induced male infertility in animal models, though clinical translation requires further study.