Ursolic Acid Ameliorates Alcoholic Liver Injury through Attenuating Oxidative Stress-Mediated Ferroptosis and Modulating Gut Microbiota

Ursolic acid (UA), a triterpenoid found in plants, has many health benefits for liver function. However, understanding how UA intervenes in alcohol-induced ferroptosis remains unclear because of the lack of research. This study explored the protective effects of UA on alcohol-induced liver injury and further elucidated its mechanism of action. Using a mouse model, acute liver injury was induced via high-dose alcohol gavage, and UA's protective effects were assessed by analyzing serum and liver indicators. The results indicated that UA has a significant protective effect against alcohol-induced liver injury in mice. UA significantly decreased serum ALT, AST, TC, and TG levels. Histopathological examination revealed that UA significantly ameliorated liver damage. UA increased ADH, ALDH, and CYP2E1 enzyme expression levels and alleviated alcohol-induced oxidative damage by regulating alcohol metabolism. Moreover, UA increased SOD and GSH-Px levels and lowered the MDA levels in the liver. Furthermore, UA regulated ACC expression by activating the LKB1/AMPK pathway, thereby inhibiting lipid synthesis and peroxidation. UA also upregulated the expression of GPX4 and SLC7A11 in the liver and exerted hepatoprotective effects by inhibiting alcohol-induced ferroptosis. Additionally, 16S rRNA amplicon sequencing showed that excessive alcohol consumption significantly affected the composition of the mouse gut microbiota, with UA intervention proving to be beneficial for improving gut microbiota imbalance. We also validated the protective effects of UA on alcohol-treated HepG2 cells at the cellular level. In summary, these results revealed that UA can alleviate alcoholic liver injury by inhibiting oxidative stress-mediated ferroptosis and regulating gut microbiota. These findings suggest that UA may serve as a functional component in the prevention of alcoholic liver disease.