Puerarin ameliorates alcoholic liver disease by regulating intestinal flora and MAPK/Nrf2 signalling pathways

Puerarin is a natural flavonoid glycoside extracted from the traditional Chinese medicine Puerariae Lobatae Radix or Pueraria lobata (Willd), known for its hepatoprotective properties. While prior studies indicate that PR can mitigate ALD, the underlying mechanisms by which PR exerts its anti-ALD effects via intestinal flora remain poorly understood. This study aimed to investigate the metabolic differences of PR in normal and ALD model rats were analyzed using UHPLC-HRMS. Further validation of PR metabolic products in vivo through in vitro fecal fermentation. Additionally, the relationship between the anti-ALD properties of PR and intestinal flora was explored using 16S rRNA sequencing technology, with confirmation obtained from fecal microbiota transplantation (FMT) experiments and functional strain experiments. Finally, through non-targeted metabolomics and liver transcriptomics combined with in vitro cell pharmacological studies, the mechanism of action of PR and its in vitro fermentation metabolites against ALD was explored. In the PR metabolic test, 20 metabolites were identified in the serum, urine, and feces of normal and ALD model rats, primarily associated with reactions including deglycosylation, hydrogenation, aldehyde esterification, hydroxylation, and methylation. 6 metabolites were verified in vitro transformation system. Subsequently, we used FMT experiments and 16S rRNA sequencing to find that intestinal flora imbalance can lead to liver disease and PR can improve liver disease by regulating intestinal flora. Based on multi-omics analysis and in vitro pharmacological activity analysis, PR and its in vitro fermented metabolites inhibit MAPK and Nrf2 pathways, further reducing inflammation and oxidative stress. The results of this study show that PR can improve ALD, with its mechanism of action potentially involving regulation of the intestinal flora, suppression of inflammatory responses, and inhibition of oxidative stress.