Abstract

Ulcerative colitis (UC), a chronic inflammatory bowel disease, remains difficult to treat due to incomplete understanding of its mechanisms and limited therapeutic options. Diosmin, a natural citrus-derived flavonoid, has shown promising anti-inflammatory effects, but its molecular mechanisms in UC are unclear. In this study, we investigated the protective role of diosmin using dextran sulfate sodium (DSS)-induced colitis in mice and LPS-stimulated HT-29 cells, integrating transcriptomic and network pharmacology analyses. Diosmin treatment significantly alleviated colitis symptoms, reduced inflammation, preserved colon length, and enhanced intestinal barrier integrity, with efficacy comparable to 5-aminosalicylic acid. RNA-seq and network pharmacology identified PI3K–Akt and NF-κB as key pathways associated with diosmin-mediated protection, while molecular docking was used as a supportive computational analysis to explore potential interactions with selected hub-associated proteins. Experimental validation confirmed that diosmin inhibited activation of PI3K–Akt–mTOR and NF-κB signaling, decreased pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), increased IL-10, promoted intestinal barrier repair via upregulation of ZO-1, occludin, and E-cadherin, and suppressed apoptosis of colonic epithelial cells. Together, these findings suggest that diosmin exerts multi-target protective effects against experimental colitis by modulating inflammation, supporting barrier integrity, and regulating key signaling pathways, providing mechanistic insight into the actions of this citrus-derived bioactive compound in colitis.