Triptolide ameliorates LPS-induced acute lung injury in Balb/c mice through gut-lung axis-mediated regulation of bile acid metabolism and gut microbiota

Acute lung injury (ALI) associated with pulmonary edema is a severe clinical condition characterized by acute inflammation, disrupted lung barrier function, and high mortality. Current therapeutic strategies remain limited, highlighting the need for exploring novel agents and their underlying mechanisms. Triptolide (TP), an active component derived from Tripterygium wilfordii, has shown anti-inflammatory and tissue-protective properties^1,2, but its specific role in alleviating ALI and the involvement of the lung-gut axis in metabolic regulation remain poorly understood. This study aims to investigate the therapeutic effects of TP on LPS-induced ALI, focusing on its impact on pulmonary edema and inflammatory injury. By analyzing the lung-gut axis using multi-omics approaches, we seek to clarify the metabolic network regulatory mechanisms through which TP exerts its effects. LPS-induced ALI model was established in Balb/c mice, with TP administered as the therapeutic intervention. Histopathological examination of lung tissues and detection of pro-inflammatory cytokines were performed to assess lung injury. Untargeted metabolomics via LC-MS/MS was used to identify differential metabolites in lung tissues and serum, while metagenomic sequencing analyzed changes in gut microbiota composition. Integrated multi-omics analysis was applied to explore associations between gut microbiota alterations, serum metabolites, and pulmonary bile acid levels. TP administration significantly reduced histopathological damage in lung tissues of ALI mice and decreased pro-inflammatory cytokine levels. Metabolomics profiling revealed distinct changes in key metabolites, including bile acids, amino acid derivatives, and energy metabolism intermediates, in both lung tissues and serum after TP treatment. Metagenomic analysis showed that TP restructured gut microbiota composition, with functional enrichment in glycolysis and thiamine metabolism pathways. Integrated analysis confirmed strong correlations between dynamic microbiota changes, serum metabolite profiles, and pulmonary bile acid levels, indicating a regulatory role of the lung-gut axis. This study demonstrates that TP alleviates pulmonary edema and inflammatory injury in ALI by modulating gut microbial ecology and function, which drives bile acid metabolic reprogramming and regulates metabolite interactions within the lung-gut axis. These findings provide novel insights into TP's therapeutic mechanism and support its potential application in ALI treatment.