Protective effects of melatonin against metabolic and reproductive disturbances in polycystic ovary syndrome in rats

ObjectivesThis study was undertaken to study the effects of melatonin on metabolic and reproductive aspects of polycystic ovary syndrome (PCOS) in rats. MethodsPCOS was induced by daily subcutaneous administration of testosterone (20mg/kg) to 21-day-old female rats for 35 days. Rats were given metformin (500mg/kg), melatonin (1mg/kg) or melatonin (2mg/kg) along with testosterone. One group served as vehicle control. On the 36th day, the animals were euthanised, and anthropometrical, biochemical (glucose, insulin, lipids, testosterone, C reactive protein (CRP)), oral glucose tolerance test, and histopathological evaluation of ovaries, uterus and intraabdominal fat (IAF), were carried out. Daily colpocytological examination was carried out from 14(th) day of study until termination. Key findingsBoth the doses of melatonin significantly reduced body weight, body mass index, IAF, insulin and CRP. A favourable lipid profile, normal glucose tolerance and a decrease in the percentage of estrus smears were observed. Histopathological examination of ovary, uterus and IAF revealed a decrease in the number of cystic follicles, decrease in neoplastic endometrial glands, and decrease in adipocyte hypertrophy, respectively. The effects observed with melatonin were comparable to that with metformin. ConclusionThe study provides evidence of the potential beneficial effects of melatonin in PCOS.