Identifying the Mechanisms and Molecular Targets of Guchang Zhixie Pills on Ulcerative Colitis: Coupling Network Pharmacology with GEO Database and Experiment Verification

Objective: This research investigates the mechanisms and molecular targets of the Guchang Zhixie pill (GCZXP) against ulcerative colitis (UC) in silico and in vivo. Methods: The compounds and related targets of GCZXP were collected from the traditional Chinese medicine systems pharmacology database. UC targets were from Gene Expression Omnibus and GeneCards databases. Hub genes were acquired through Cytoscape. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment were performed in the David database. R packages were used to investigate the relationship between immune cells and hub genes and the diagnostic model. AutoDock was used to verify the molecular docking of the core compounds and hub genes, as well as nuclear factor-kappa B (NF-κB) p65 and IκBα. The hub genes and NF-κB pathway were verified via experiment. Results: In GCZXP, a total of 51 active compounds were discovered. Enrichment analysis was used to study inflammation, chemokine activity, NF-κB signalling pathway, etc. Thirteen key therapeutic targets were involved, of which included three hub genes PTGS2, IL-1β and CXCL8. Immune infiltration revealed that all of the 3 hub genes were positively correlated with M1 macrophages, neutrophils, and activated memory CD4 cells, and negatively correlated with plasma cells. In the training and validation sets, the area under the curve (AUC) of the diagnostic model developed by hub genes reached 0.929 and 0.905, respectively, indicating a good forecasting potential. The rat experiment proved that GCZXP significantly reduced the expressions of IL-1β, CXCL8, COX-2, and NF-κB p65 while increasing IκBα and Bcl-2, alleviated colonic inflammatory injury and promoted ulcer healing. Conclusion: GCZXP reduced the release of cytokines and regulated Bcl-2 in the treatment of UC by inhibiting the NF-κB signalling pathway.