An integrated approach combining chemical profiling and in vivo evaluation reveals the critical role of vinegar-processing in Hao-Chi-Dan for treating ulcerative colitis

Ethnopharmacological relevance Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by a high clinical recurrence rate. Hao-Chi-Dan (HCD) is a Chinese herbal formula widely used in the clinical treatment of gastrointestinal pain and bleeding. However, the efficacy of HCD for UC and the impact of processing methods for its key ingredient, Artemisiae Argyi Folium (AAF), on therapeutic outcomes remain unclear. Aim of the study This study aimed to evaluate the efficacy of HCD against UC and to investigate the potential active components and mechanisms of action of HCD formulated with vinegar-processed AAF (VHCD). Materials and methods Chemical profiles of HCD formulated with raw, vinegar-processed, and vinegar-charred AAF were characterized by UPLC-QTOF-MS/MS and HS-GCMS. A dextran sulfate sodium salt (DSS)-induced murine UC model was used to assess the efficacy of different HCD formulations. Disease activity, colon histopathology, inflammatory cytokines, gut microbiota, and short-chain fatty acids (SCFAs) were analyzed. Results HCD significantly alleviated DSS-induced colitis. Crucially, VHCD demonstrated superior efficacy in ameliorating disease activity, colon shortening, and tissue damage, without inducing hepatorenal toxicity. Chemical analysis identified terpenoids and flavonoids as major components. VHCD treatment modulated the gut microbiota structure, increased beneficial SCFAs, and reduced pro-inflammatory cytokines. Conclusion Vinegar-processing is essential for enhancing the anti-colitis efficacy of HCD. The effect is associated with modulation of gut microbiota, increased SCFA production, and attenuated inflammation. Our findings provide a scientific basis for the optimized application of HCD in UC management.