Protective Effects of Melatonin and Vitamin E Against Ovarian Damage Induced by Pelvic Radiotherapy

Object: To investigate the protective effects of melatonin and vitamin E against pelvic radiotherapy-induced ovarian radiation injury. Method: Thirty-two mature female mice were randomly divided into four groups: the irradiation-only group, the vitamin E-administered irradiation group, the melatonin-administered irradiation group, and the vitamin E + melatonin-administered irradiation group. All drug-irradiated groups received intraperitoneal injections of melatonin and/or vitamin E starting 3 weeks before irradiation. Then, the drug-irradiated and irradiation-only groups underwent a total dose of 2 Gy (1 Gy/session * 2 sessions) of local pelvic radiotherapy. Post-radiotherapy, the drug-irradiated groups continued receiving intraperitoneal injections of melatonin and/or vitamin E for 2 weeks. Serum levels of anti-Müllerian hormone (AMH), estradiol, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured, along with estrus cycle monitoring and follicle count comparisons. Results: Compared with the irradiation-only group, the vitamin E-administered and vitamin E+ melatonin-administered irradiation groups showed improvements in disrupted estrous cycles (p<0.05). All drug-irradiated groups improved hormonal levels of ovaries, with statistically significant differences, and combined use provided superior effects (p<0.05). Melatonin and vitamin E administration also increased the number of functional follicles, reduced atretic follicles, and increased total follicle numbers, with synergistic effects being superior (p<0.05). Conclusion: Both melatonin and vitamin E provide protective effects against pelvic radiotherapy-induced ovarian damage, with combination therapy offering the best outcomes.