Oxytocin Attenuates Metabolic Dysfunction-associated Steatotic Liver Disease via AMPK/SREBP1c/FAS-mediated Suppression of Hepatic Lipogenesis.

As the leading cause of chronic liver disease globally, metabolic dysfunction-associated steatotic liver disease (MASLD) lacks effective therapies. This study aimed to investigate the therapeutic potential and molecular mechanisms of oxytocin (OXT) in MASLD. Integrated bioinformatics analysis of MASLD datasets was carried out to identify OXT-related metabolic disturbances. Serum OXT levels were quantified using an enzyme-linked immunosorbent assay in 113 MASLD patients and 63 healthy controls. Mechanistic assays were conducted using oleic acid (OA)-induced, lipid-loaded HepG2 cells and high-fat diet-fed C57BL/6 mice, and OXT was administered intraperitoneally in vivo and supplemented in vitro. Bioinformatics analysis revealed significant changes in OXT expression levels, particularly in fatty acid metabolism. Elevated OXT expression levels in MASLD patients were identified as an independent prognostic factor. In vitro, OXT significantly reduced OA-induced lipid accumulation in HepG2 cells, while in vivo, it decreased body weight, liver injury, and serum cholesterol levels in high-fat diet-fed mice. Mechanistically, OXT enhanced the expression level of phosphorylated AMP-activated protein kinase (AMPK) and suppressed the levels of sterol regulatory element-binding protein-1c (SREBP1c) and fatty acid synthase (FAS). Blockade of AMPK with the chemical inhibitor Compound C reversed the ability of OXT to suppress the SREBP1c/FAS axis and reduce lipid accumulation in hepatocytes. Additionally, OXT inhibited the nuclear translocation of SREBP1c in OA-treated cells. The findings demonstrate that OXT may serve as a potential therapeutic agent for MASLD by regulating the AMPK/SREBP1c/FAS pathway in lipid metabolism.