〔Abstract〕 Objective To investigate the effects of polydatin on a high-fat diet-induced non-alcoholic fatty liver disease (NAFLD) mouse model and hepatoma G2 (HepG2) cell model, and to reveal its potential molecular mechanisms. MethodsThirty 6-week-old male SPF C57BL/6J mice were randomly divided into a normal diet group and a high-fat diet group. After the NAFLD mouse model was established in the high-fat diet group, they were further divided into a model group and a polydatin treatment group. The polydatin treatment group was administered polydatin by gavage at a dose of 250 mg/(kg·d) for 10 weeks, during which body weight was monitored and oral glucose and insulin tolerance tests were performed. At the end of the experiment, a series of tests to evaluate the effects of polydatin on mouse liver weight, blood lipids, liver lipid accumulation, and liver injury markers were performed. The expression of G 0/G 1 switch gene 2(G0S2) and adipose triglyceride lipase (ATGL) was measured by qRT-PCR and Western blot, and gene expression was further verified using immunohistochemical staining. The effects of polydatin on HepG2 cell activity was assessed by CCK-8 assay, lipid accumulation was observed by oil red O staining, and the expression of G0S2 and ATGL was detected by qRT-PCR and Western blot. Results Polydatin significantly reduced the body weight, liver weight, and serum and liver tissue levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and total cholesterol (TC) in mice ( P<0.05), alleviated pathological liver damage, decreased G0S2 expression ( P<0.05), and increased ATGL expression ( P<0.05). At the cellular level, polydatin reduced lipid droplet accumulation, improved lipid metabolism, decreased G0S2 expression ( P<0.05), and increased ATGL expression ( P<0.05). Even in cells with knockdown of G0S2, polydatin still promoted fat decomposition ( P<0.01). Conclusion Polydatin promotes hepatic fat breakdown by regulating the expression of G0S2 and ATGL, helping to alleviate metabolic disorders and liver damage in the NAFLD mouse model caused by a high-fat diet, offering a new strategy for treating NAFLD.