Shentao Ruangan Granule Ameliorates Cholestatic Liver Disease via a Microbiota-Dependent Gut-Liver Axis.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: The Shentao Ruangan (STR) Granule, developed under Traditional Chinese Medicine (TCM)'s "Gan Bing Zhi Pi" (treating liver via spleen) theory, shows promise in cholestatic liver disease (CLD). TCM's "Pi Xu" (spleen deficiency) in CLD links to gut microbiota dysregulation, but STR's mechanisms remain unclear. AIM OF THE STUDY: To decipher the anti-CLD mechanisms of STR, focusing on how it translates the "Gan Bing Zhi Pi" theory into biological effects via the gut-liver axis. MATERIALS AND METHODS: This study employed an α-naphthyl isothiocyanate (ANIT)-induced C57BL/6 mouse model to verify the therapeutic efficacy of STR. Network pharmacology was utilized to predict underlying mechanisms; 16S sequencing characterized STR's effects on gut microbiota composition, and analysis via the gutMGene database helped elucidate STR's role in CLD. Finally, in vivo experiments assessed TLR4/NF-κB pathway expression and intestinal barrier function, with dual validation through gut microbiota depletion and transplantation assays, to unravel the molecular mechanisms underlying STR-mediated CLD amelioration. RESULTS: STR ameliorated CLD by normalizing gallbladder index and serum ALP, TBA, TBIL, ALT, and AST, while attenuating hepatic inflammation. Network pharmacology identified 134 potential STR targets related to CLD, underscoring microbiota dysbiosis and inflammation and revealing LPS-related TLR4-mediated inflammatory pathways as regulatory hubs. 16S sequencing demonstrated STR-modulated gut microbiota, enriching Bacteroidetes and Akkermansia while depleting Enterococcus. These changes were associated with enhanced fecal bile acid excretion, intestinal barrier repair, and suppressed TLR4-mediated inflammatory cascades. Integrated network pharmacology/16S/gutMGene analyses established TLR4-mediated inflammation as the core microbiota-dependent mechanism. In vivo experiments confirmed STR reduced serum LPS, increased fecal bile acids, inhibited hepatic TLR4/NF-κB activation, and enhanced intestinal barrier integrity by upregulating tight junction proteins (ZO-1, occludin). These mechanisms were validated via gut microbiota depletion and transplantation assays. CONCLUSION: STR ameliorates CLD via a microbiota-dependent "Gan Bing Zhi Pi" mechanism. By reshaping the gut microbiota, it coordinates bile acid excretion, repairs intestinal barrier, and suppresses LPS-driven hepatic inflammation to regulate the gut-liver axis. This bridges TCM theory with modern microbiology, validating the therapeutic potential of STR for CLD.