Our findings revealed increased expression levels of β -oxidation-related genes (ACOX, PPARa, Angptl4, and cpt1b) in liver tissue treated with UC-MSCs pretreated with exogenous mitochondria, indicating that pretreated UC-MSCs enhance the restorative ability of MSCs to promote β-oxidation in NAFLD, thereby improving liver function and mitigating liver tissue injury. This evidence concerns the gene ACOX1 and metabolic dysfunction-associated steatotic liver disease.