Berberine ameliorates primary biliary cholangitis by modulating the gut–liver axis and attenuating cholangiocyte oxidative stress in murine models and human organoids

Background Primary biliary cholangitis (PBC) is a chronic autoimmune cholestatic liver disease characterized by progressive destruction of intrahepatic bile ducts, resulting in liver inflammation and fibrosis. Despite ursodeoxycholic acid as the standard therapy, a substantial proportion of patients show incomplete responses. Berberine hydrochloride (BBR), a bioactive alkaloid derived from traditional Chinese medicine, exhibits anti-inflammatory, antioxidant, and microbiota-modulating properties. While BBR has shown therapeutic potential in primary sclerosing cholangitis, its efficacy and underlying mechanisms in PBC remain largely unexplored. Purpose This study was designed to explore the therapeutic potential of BBR and elucidate its underlying mechanisms in the treatment of PBC. Methods We established a murine PBC model by intraperitoneal injection of 2-octynoic acid–BSA. BBR was then administered to the mice via oral gavage. Liver injury and fibrosis were evaluated using hematoxylin and eosin staining, Sirius red staining, immunohistochemistry, reverse transcription-quantitative PCR (RT-qPCR), liver function tests, and transcriptomic analysis. Gut microbiota composition was analyzed by 16S rRNA gene sequencing. To address how BBR protects biliary epithelial cells from oxidative stress injury, we employed an in vitro H₂O₂‑induced injury model in human bile‑derived cholangiocyte organoids. Mechanistic insights were then sought through transcriptomic and Olink proteomic analyses, with key findings validated by RT‑qPCR, immunofluorescence, transmission electron microscopy, and ELISA. Results BBR markedly ameliorated liver inflammation and fibrosis in PBC mice and significantly modulated gut microbiota composition. Mechanistically, these effects were associated with the upregulation of bile secretion–related pathways,peroxisome proliferator-activated receptor and glutathione metabolic pathways. In cholangiocyte organoids, BBR attenuated oxidative stress–induced injury by suppressing pro-inflammatory cytokine signaling, restoring mitochondrial function, and enhancing metabolic adaptation. Conclusion These findings indicate that BBR exerts protective effects against PBC by targeting the gut–liver axis and cholangiocyte oxidative stress responses, supporting its potential as a promising therapeutic candidate for PBC.