Kui-Jie-Ling capsule inhibits ulcerative colitis by modulating inflammation and gut microbiota.

Background and aim: Kui-Jie-Ling capsule (Kui-Jie-Ling) is a hospital preparation for ulcerative colitis (UC) in China. This study aimed at evaluating the protective effects and mechanisms of Kui-Jie-Ling and Kui-Jie-Ling combined with adalimumab on UC induced by dextran sulfate sodium (DSS).

Methods: Network pharmacology was combined with an animal experiment to reveal the targets of Kui-Jie-Ling alleviating UC. The UC model was established by drinking 2.5% DSS solution for 7 days. On the second day, the mice in the Kui-Jie-Ling group were orally administered with Kui-Jie-Ling (1.5 and 3.0 g/kg) daily for seven consecutive days, and the mice in the combination group were orally administered with Kui-Jie-Ling (3.0 g/kg) once a day for seven consecutive days and received one subcutaneous injection of adalimumab. The disease activity index, the colon length, the spleen index, the cytokines, the colon, the short-chain fatty acid content, and the gut microbiota in the colon were analyzed. The role of gut microbiota against UC was verified by fecal microbiota transplantation experiments.

Results: The animal study's results were consistent with the network pharmacology analysis, which reflected that Kui-Jie-Ling alleviated UC via multi-pathway. Kui-Jie-Ling ameliorated UC by inhibiting the formation of neutrophil extracellular traps (NETs), regulating inflammatory factors through the lipopolysaccharide-toll-like receptor 4/nuclear factor kappa B and interleukin-23-Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway, and restoring intestinal homeostasis.

Conclusion: These studies provided the experimental basis for the clinical administration of Kui-Jie-Ling and Kui-Jie-Ling combined with adalimumab against UC.