Melatonin attenuates hepatic oxidative stress by regulating the P62/LC3 autophagy pathway in PCOS

The elevated level of hepatic oxidative stress (OS) in polycystic ovary syndrome (PCOS) is one of the important causes of liver abnormalities. Therefore, decreasing the level of hepatic OS in PCOS is beneficial to reduce the risk of PCOS-related liver diseases. Melatonin (MT), recognized as a potent antioxidant. Nevertheless, the efficacy of MT in alleviating hepatic OS associated with PCOS is yet to be established, and the precise mechanisms through which MT exerts its antioxidant effects remain to be fully elucidated. The aim of this study was to explore the potential mechanism by which MT reduces hepatic OS in PCOS. First, we detected elevated OS levels in the PCOS samples. Subsequently, with MT pretreatment, we discovered that MT could significantly diminish the levels of OS, liver triglyceride (TG), total cholesterol (TC), alanine aminotransferase (ALT) and aspartate aminotransferase (AST)，while concurrently ameliorating mitochondrial structural damage in PCOS liver. Furthermore, we identified elevated autophagy levels in the liver of PCOS rats and an inhibition of the Keap1-Nrf2 pathway. Through MT pretreatment, the expression of LC3 was significantly decreased, while the Keap1-Nrf2 pathway was activated. Our study showed that MT could affect the Nrf2 pathway dependent on the P62/LC3 autophagy pathway, thereby attenuating hepatic OS in PCOS. These findings offer novel insights and research avenues for the study of PCOS-related liver diseases.