ObjectiveThis study aims to explore the potential mechanism of the Xiezhuo Jiedu formula in regulating pyroptosis for the treatment of ulcerative colitis （UC） using bioinformatics and in vivo animal experiments.MethodsDifferentially expressed genes （DEGs） in colon tissues of UC patients were retrieved from the Gene Expression Omnibus （GEO） database. Pyroptosis-related genes were obtained from the GEO and GeneCards databases. The intersection of these datasets yielded pyroptosis-related DEGs （Pyro-DEGs）. Pyro-DEGs were subjected to Gene Ontology （GO） and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment analysis using the Metascape database. A protein-protein interaction （PPI） network was constructed using the STRING database. Least absolute shrinkage and selection operator （LASSO） prediction model and receiver operating characteristic （ROC） analysis were conducted to identify core Pyro-DEGs with diagnostic and therapeutic potential. Immune infiltration analysis of the UC datasets was performed using the deconvolution method （CIBERSORT）， along with correlation analysis with core Pyro-DEGs. Sixty male Sprague-Dawley （SD） rats were randomly divided into a control group， a model group， high-， medium-， and low-dose groups of Xiezhuo Jiedu formula （26.64， 13.32， 6.66 g·kg^-1）， and a mesalazine group （0.27 g·kg^-1）， with 10 rats in each group. UC was established by intrarectal administration of 3，5-trinitrobenzenesulfonic acid （TNBS） dissolved in ethanol. The control and model groups were given distilled water by gavage， while the treatment groups were administered the corresponding drugs for 7 consecutive days. Hematoxylin-eosin （HE） staining was used to observe the colon histopathology. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of inflammatory factors such as interleukin-1β （IL-1β）， IL-10， IL-18， and transforming growth factor-β （TGF-β）. Immunohistochemistry （IHC） and Western blot were applied to detect the expression of Caspase-1， gap junction alpha-1 protein （GJA1）， peroxisome proliferator-activated receptor gamma （PPARG）， and S100 calcium-binding protein A8 （S100A8）. Real-time quantitative polymerase chain reaction （Real-time PCR） was utilized to measure mRNA expression of Caspase-1， GJA1， PPARG， and S100A8. Western blot was performed to assess protein expression levels of Caspase-1， GJA1， PPARG， and S100A8.ResultsGEO datasets GSE87466 and GSE87473 yielded 64 Pyro-DEGs. KEGG analysis indicated that these genes were enriched in the NOD-like receptor signaling pathway， tumor necrosis factor （TNF） signaling pathway， and hypoxia-inducible factor 1 （HIF-1） signaling pathway. Four core Pyro-DEGs （Caspase-1， GJA1， PPARG， and S100A8） were identified. Immune infiltration analysis showed that expression of these genes was positively correlated with mast cells， neutrophils， M0 macrophages， M1 macrophages， and dendritic cells. Animal experimental results indicated that compared with the control group， the model group had significantly increased levels of IL-1β and IL-18， significantly decreased levels of IL-10 and TGF-β. The model group showed enhanced Caspase-1， GJA1， and S100A8 staining， and significantly increased mRNA and protein expression of Caspase-1， GJA1， and S100A8 （P<0.01）. In contrast， the expression of PPARG was reduced in the model group （P<0.01）. After treatment， all dosage groups showed varying degrees of improvement （P<0.05， P<0.01）， with the high-dose group showing the most significant improvement （P<0.01）.ConclusionCaspase-1， GJA1， PPARG， and S100A8 are core Pyro-DEGs closely associated with the pathogenesis of UC. These genes may collaborate with immune cells such as mast cells， neutrophils， and M0 macrophages to mediate disease development. The Xiezhuo Jiedu formula may regulate the expression of core Pyro-DEGs through the NOD-like receptor， TNF， and HIF-1 core signaling pathways， thereby modulating immune homeostasis in UC rats and effectively alleviating UC.

bioinformatics;Xiezhuo Jiedu formula;pyroptosis;ulcerative colitis