Modulatory Effect of Dihydromyricetin on Chronic Alcoholic Liver Injury Based on the FXR-NLRP3 Signaling Pathway and Serum and Liver Metabolomics

In modern diets, alcohol consumption has led to an increase in the number of cases of alcohol-related liver disease (ALD). Dihydromyricetin (DMY) is commonly used as a hepatoprotective agent owing to its remarkable efficacy in treating chronic alcoholic liver injury; however, its mechanism of action is unclear. The object of the study is to investigate the effect and mechanism of DMY in alleviating chronic ALD. A mouse model of chronic ALD was established. Mice were treated with DMY for 56 days, and their biochemical parameters including liver function, blood lipids, and oxidative stress-related indices were measured. Farnesoid X receptor (FXR) expression, NOD-like receptor protein 3 (NLRP3) pathway-related protein expression, and inflammation-related gene expression were determined to elucidate the mechanism of DMY in mice with ALD. Lastly, serum and liver metabolomics-based UHPLC-Orbitrap Exploris MS analyses were used to determine the influence of the metabolism of DMY on mice with ALD. Pharmacodynamic studies showed that DMY could decrease aspartate transaminase, alanine transaminase, triglyceride, and low-density lipoprotein cholesterol levels, improve superoxide dismutase activity, and reduce inflammation in mice with ALD. DMY treatment protects the liver by increasing FXR protein expression and by decreasing NLRP3 pathway-related protein expression and inflammatory gene expression. Metabolomics analysis indicated that ethanol treatment mainly altered metabolism in mice. DMY could regulate 10 metabolites in serum, namely, N-α-acetyllysine, 1-pyrrolinecytosine, glutamyllysine, 5-methylcytosine, N-methylvaline, pyridoxamine, demethoxycurcumin, L-arginine, triacetin, and 15-methylpalmitate. It could also regulate 31 metabolites in the liver, including L-methionine and L-leucine. DMY treatment altered the following important pathways: valine, leucine, and isoleucine biosynthesis; cysteine and methionine metabolism; and valine, leucine, and isoleucine degradation. Correlation analyses using heatmaps revealed that the metabolic parameters are closely related to the pharmacodynamic index. These findings indicated that DMY alleviated ALD by regulating the FXR-NLRP3 signaling pathway and could treat serum and liver metabolic disorders.