Elucidating the Mechanism of Fusu Agent Against Sepsis-Induced Acute Respiratory Distress Syndrome via an Integrated Approach Combining Network Pharmacology, Molecular Dynamics Simulations, and Experimental Validation

Background: Sepsis represents a critical medical condition that frequently progresses to acute respiratory distress syndrome (ARDS). While the traditional Chinese medicine Fusu agent (FSHJ) is clinically effective, its precise mechanisms in sepsis-induced ARDS remain unclear. Methods: To elucidate the therapeutic mechanisms of FSHJ in sepsis-induced ARDS, we implemented an integrated multi-method strategy combining network pharmacology, molecular dynamics simulations (MDS), liquid chromatography-mass spectrometry (LC-MS), and in vivo validation. Active compounds and targets of FSHJ were identified from Batman-TCM 2.0, followed by protein–protein interaction network construction via STRING. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses were performed using clusterProfiler in R. Molecular docking with AutoDock Vina assessed binding affinities, and MDS with GROMACS verified complex stability. LC-MS confirmed the predicted bioactive components, while animal models experimentally validated the associated signaling pathways. Results: A total of 537 shared therapeutic targets were pinpointed among FSHJ, ARDS, and sepsis. Integrative assessments of protein–protein interaction (PPI) networks along with GO and KEGG enrichment analyses highlighted that the anti-sepsis-induced ARDS activity of FSHJ is predominantly mediated through inflammatory response regulation. Docking simulations combined with molecular dynamics analyses demonstrated that the key bioactive compound quercetin exhibited robust and sustained interactions with specific protein targets. LC-MS analyses further authenticated the presence of anticipated active compounds, particularly the glycoside derivative quercetin-3β-D-glucoside. Furthermore, all three doses of FSHJ effectively alleviated pathological lung tissue damage and systemic inflammatory responses induced by Escherichia coli ( E. coli ) infection. Relative to the control (model) group, FSHJ markedly suppressed the mRNA expression of inflammatory cytokines IL-6, IL-1β , and TNF-α , and decreased protein expression levels of TLR4 and NF-κB p65. Conclusion: Our findings indicate that FSHJ exerts protective effects in an E. coli -induced sepsis-associated ARDS mouse model, potentially through the regulation of TLR4/NF-κB-mediated inflammatory signaling pathways. Keywords: Fusu agent, acute respiratory distress syndrome, sepsis, network pharmacology, molecular dynamics simulations, Escherichia coli ( E. coli )