Melatonin Alleviates Biochemical, Hormonal and Histoarchitectural Alterations in a PCOS Rat Model Exposed to Constant Light by Enhancing Antioxidative Enzymes

Abstract

The study evaluated the impact of pineal hormone (melatonin) on reproductive impairment induced by constant light/ photoperiodic stress in female Rattus norvegicus. The experimental design consists of 24 female rats weighing 170 ± 10 gm. A total of 24 rats were equally divided into two major groups comprising 12 rats each. Further, 12 rats were kept under constant light (600lux) for 60 days to induce PCOS. After confirmation of PCOS by regular observation of vaginal smear, these two major groups were further divided into 4 groups containing 6 rats in each. Again 12 rats with no treatment were divided as control (0.9% saline) and melatonin (200µg/100gm bw). However, rats exposed to the constant light were divided into LL (PCOS) and PCOS+MEL with six rats in each group. After 21 days, the rats were sacrificed, and their ovaries and oviducts were harvested. Blood samples were collected for corticosterone and melatonin, androgen and estradiol analysis, and harvested tissues were stored at -80⁰c for further assessment. The results showed that polycystic ovarian rats exhibited increased body weight and anti-oxidative enzyme levels. However, the polycystic ovarian rats, that were treated with melatonin showed recovery with melatonin, corticosterone, body and tissue weight, and biochemical parameters. The study suggests that continued light exposure can induce reproductive disorder by disrupting Gonadotropic rhythmicity, but melatonin treatment restores reproductive homeostasis. The study provides insights into polycystic ovarian syndrome pathogenesis and the potential therapeutic benefits of melatonin.