The effect of Melatonin on histological changes of ovary in induced polycystic ovary syndrome model in mice

Abstract

Antioxidants can be used as adjuvant treatment of polycystic ovary syndrome (PCOS). Melatonin (MT) is one of the antioxidant that is used nowadays. In this study, the effect of MT on the histological changes of ovary in the experimental model of polycystic ovary syndrome is investigated. In this study 30 immature female NMRI mice were divided into 5 groups including: (1) control group received distilled water, (2) received a dose of 10 mg/kg MT for 5 days, (3) received Dehydroepiandrostenedione (DHEA) at a dose of 6 mg/kg for 20 days to induce PCOS, (4) after induction of PCOS received MT at a dose of 10 mg/kg for 5 days, and (5) received 6 mg/kg DHEA and 10 mg/kg MT for 20 days simultaneously. The evaluation of ovarian tissue characteristics such as the granulosa layer, theca, number and diameter of cysts and follicles was performed. PCOS caused a significant reduction in the number of antral follicles and corpus luteum and an increase in the number of primordial, primary, pre-antral and cystic follicles in comparison with the control group (P < 0.05). Moreover, MT resulted in a significant increase in the granulosa layer thickness in group 4 (P < 0.001), and group 5 (P = 0.001) and a significant reduction in the thickness of theca layer between groups 4 and 5 compared with group 3 (P < 0.001). These findings indicate that MT have a protective effects on polycystic ovary damages induced by DHEA, although the mechanism is unclear. It is likely that this is happening by reducing oxidative damage.