Validate the Treatment of Crohn's Disease with Chaihu Guizhi Decoction Through Network Pharmacology, Molecular Dynamics Simulation, and in vivo Experiments.

Objective: Using an integrated strategy combining network pharmacology, molecular dynamics simulations, and in vivo experiments, this study explores the stage-specific targets of Chaihu Guizhi Decoction (CGD) for the treatment of Crohn's disease (CD). Methods: First, through the GEO database, the patients with Crohn's disease were divided into four groups: early patients (NCD), late patients (LCD), patients with postoperative recurrence (PCD) and patients without postoperative recurrence (UPCD), and the differential genes of each group were screened. Active ingredients in Chaihu Guizhi Decoction (CGD) with an oral bioavailability (OB) greater than 30% and drug-likeness (DL) exceeding 0.18 were screened using the TCMSP database, along with their corresponding potential targets. The target of CGD was intersected with four groups of differential genes. The common therapeutic targets of CGD for Crohn's disease in four groups and the specific therapeutic targets of each group were obtained. Core targets were identified through protein-protein interaction (PPI) network analysis. The potential mechanism of CGD in treating Crohn's disease was analyzed by enrichment of KEGG and GO. Finally, molecular docking and molecular dynamics simulation were used to verify the possibility of combining the effective ingredients of CGD with the therapeutic target of Crohn's disease. Construct a mouse model of inflammatory bowel disease and administer drug treatment. Use mouse intestinal tissue for Elisa, HE staining, and AB-PAS staining to validate the potential of drug therapy for inflammatory bowel disease. Meanwhile, Western blot experiments were conducted to verify the effect of quercetin on the expression of downstream target proteins. Results: Through molecular docking verification, quercetin can bind to these six core genes. We analyzed quercetin and six gene protein products through molecular dynamics simulation. We found that the complex of quercetin and PTGS2 protein is relatively stable, which may be a therapeutic target. In animal studies, both CGD and quercetin significantly alleviated inflammation-induced intestinal shortening (p < 0.05). ELISA results demonstrated that CGD and quercetin markedly reduced the expression of pro-inflammatory cytokines, including IL-6, IL-1β, and TNF-α (p < 0.05). Furthermore, histopathological examinations via HE and PAS staining revealed a substantial mitigation of intestinal inflammation following treatment with CGD and quercetin. Conclusion: This study found through animal experiments that CGD and quercetin can treat CD. Through network pharmacology, molecular dynamics simulations, and Western blot experiments, it was demonstrated that quercetin can treat inflammatory bowel disease by affecting the expression of PTGS2 and IL-1B proteins.