Investigation of the Active Ingredients and Mechanism of Hudi Enteric-Coated Capsules in DSS-Induced Ulcerative Colitis Mice Based on Network Pharmacology and Experimental Verification

Background: Hudi enteric-coated capsule (HDC) is a Chinese medicine prescribed to treat ulcerative colitis (UC). However, its anti-inflammatory active ingredients and mechanisms remain unknown. This study aimed to investigate the active components of HDC and explore its potential mechanisms against UC by integrating network pharmacology and experimental verification. Methods: A DSS-induced colitis murine model was established to validate the efficacy of HDC by detecting disease activity index (DAI) and histopathological changes. Network pharmacological analysis was performed to identify the active compounds and core targets of HDC for the treatment of UC. The main compounds in HDC were identified by highperformance liquid chromatography. The relative expressions of HDC's core targets were also determined in vivo. Finally, molecular docking was applied to model the interaction between HDC and target proteins. Results: In an in vivo experiment, HDC, especially the middle-dose HDC, effectively reduced clinical symptoms of UC, including weight loss, bloody stool, and colon shortening. Besides, the severity of colitis was considerably suppressed by HDC as evidenced by reduced DAI scores. A total of 118 active compounds and 69 candidate targets from HDC closely related to UC progression were identified via network pharmacology. Enrichment analysis revealed that the key targets of HDC correlated with the expressions of PTGS2, TNF-alpha, IL-6, and IL-1 beta. Meanwhile, these cytokines were enriched in various biological processes through the IL-17/JAK2/STAT3 signaling pathway. The middle-dose HDC contributed more to ameliorating DSS-induced colitis through this signaling pathway than other dosages. Nine components binding to JAK2, STAT3, IL-17 and IL-6 were identified by molecular docking, confirming again the inhibition effects of HDC on the IL-17/JAK2/ STAT3 signaling pathway. Conclusion: The HDC treatment, particularly the middle-dose, exerted an anti-UC effect in a multi-component, multi-target, and multi-mechanism manner, especially inhibiting the IL-17/ JAK2/STAT3 signaling pathway to downregulate the secretion of proinflammatory cytokines.