Tibetan medicine Siwei Zhixie Mutang powder ameliorates ulcerative colitis by suppressing JAK2/STAT3 and NF-κB signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: Siwei Zhixie Mutang Powder (SZMP) is a traditional Tibetan herbal formula widely used for gastrointestinal disorders, including enteritis, colitis, abdominal pain, diarrhea, and dysentery. Since ulcerative colitis (UC) is a chronic inflammatory disorder of the colon within the broader spectrum of intestinal inflammatory diseases, the traditional use of SZMP provides an ethnopharmacological basis for investigating its effects in experimental colitis. However, its key bioactive constituents and underlying molecular mechanisms remain poorly defined.

AIM OF THE STUDY: This study aimed to identify the principal active compounds, potential targets, and molecular mechanisms by which SZMP exerts protective effects against DSS-induced ulcerative colitis.

MATERIALS AND METHODS: An integrative strategy combining UPLC-MS/MS analysis, network pharmacology, transcriptomics, molecular docking, molecular dynamics simulation (MD), microscale thermophoresis (MST), and in vivo experimental validation was established. A DSS-induced ulcerative colitis mouse model was used to evaluate disease activity, histopathological injury, inflammatory responses, apoptosis-related changes, and the activation status of the JAK2/STAT3 and NF-κB signaling pathways.

RESULTS: UPLC-MS/MS identified 40 major constituents in SZMP, and 132 potential bioactive compounds with 913 predicted targets were retained after SwissADME screening. Integrated network pharmacology and transcriptomics revealed that SZMP mainly regulated inflammation- and apoptosis-related processes, particularly the JAK-STAT and NF-κB pathways. In DSS-induced colitis mice, SZMP alleviated disease symptoms, colonic injury, inflammatory cytokine overproduction, and excessive apoptosis, while inhibiting JAK2/STAT3 and NF-κB activation. UPLC-MS/MS quantification showed low levels of aristolochic acid A and strychnine in SZMP, and no obvious toxicity-related signs or major organ abnormalities were observed after 7 days of administration. Docking, MD simulation, and MST further supported a stable and direct interaction between (+)-catechin and TNFR1.

CONCLUSION: SZMP protected against DSS-induced ulcerative colitis, possibly through multi-constituent regulation of inflammation- and apoptosis-related targets, mainly involving the JAK2/STAT3 and NF-κB pathways. MD simulation and MST further showed that (+)-catechin directly bound to TNFR1, suggesting its potential role in modulating the TNF/TNFR1-NF-κB inflammatory axis. In addition, UPLC-MS/MS quantification and 7-day safety evaluation indicated low exposure levels of aristolochic acid A and strychnine, with no obvious toxicity-related signs or major organ abnormalities observed under the experimental conditions. These findings provide experimental evidence for the pharmacodynamic basis, mechanism, and short-term safety profile of SZMP in UC intervention.