Coixol attenuates Ulcerative Colitis by modulating the ILC3 response via the Wnt/β-catenin pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Coicis Semen is a classic example of a resource used both as food and medicine. In traditional Chinese medicine, it is known for several functions: promoting diuresis, resolving dampness, strengthening the spleen, stopping diarrhea, draining pus, and removing toxins. For a long time, it has been widely used to relieve symptoms of gastrointestinal disorders. In particular, Coixol shows strong biological activity when it comes to regulating intestinal inflammation. However, its specific therapeutic potential and underlying mechanisms in ulcerative colitis (UC) have not been fully elucidated. AIM OF THE STUDY: This research aimed to define the therapeutic potential of Coixol in ulcerative colitis and clarify its regulatory influence on the Axin1-mediated Wnt signaling axis and the subsequent activation of group 3 innate lymphoid cells (ILC3). MATERIALS AND METHODS: We established a colitis model in mice using dextran sulfate sodium and utilized LPS-stimulated macrophages for in vitro assays. Therapeutic outcomes were measured through disease activity scores, tissue histology, and epithelial barrier assessment. We integrated bulk RNA sequencing and Olink proteomics to pinpoint core regulatory pathways. We then validated Axin1 as the direct molecular target of the drug using molecular docking, surface plasmon resonance, and cellular thermal shift assay. Mechanistic insights were further substantiated by Western blot, flow cytometry, and a pharmacological rescue experiment using a Wnt signaling activator. Finally, the functional necessity of this axis was confirmed via IL-22 neutralization assays, demonstrating the regulatory link between Axin1 and the observed phenotypic changes. RESULTS: Coixol intervention significantly lowered inflammatory markers and promoted the restoration of the intestinal wall. Coixol modulated macrophage polarization and increased Axin1 protein levels to trigger the degradation of β-catenin. Furthermore, flow cytometry demonstrated that Coixol expanded the colonic ILC3 population, a process essential for driving IL-22-dependent mucosal healing. This protective effect was reversed by an IL-22-neutralizing antibody. CONCLUSION: Coixol effectively mitigates experimental colitis by targeting the Axin1 and Wnt axis to promote ILC3 expansion and subsequent IL-22 production. These results provide a modern scientific foundation for the traditional medicinal use of Coicis Semen and highlight the Axin1 and ILC3 module as a viable target for treating UC.