OBJECTIVES: To investigate the mechanism through which pinostrobin (PSB) alleviates dextran sulfate sodium (DSS)-induced colitis in mice.
METHODS: C57BL/6 mice were randomized into control group, DSS model group, and PSB intervention (30, 60, and 120 mg/kg) groups. Colitis severity of the mice was assessed by examining body weight changes, disease activity index (DAI), colon length, and histopathology. The expressions of tight junction proteins ZO-1 and claudin-1 in the colon tissues were examined using immunofluorescence staining, and macrophage infiltration and polarization were analyzed with flow cytometry. ELISA and RT-qPCR were used for detecting the expressions of inflammatory factors (TNF‑α and IL-6) and chemokines (CCL, CXCL, and CXCL) in the colon tissues, and PI3K/AKT phosphorylation levels were analyzed with Western blotting. In cultured Caco-2 and RAW264.7 cells, the effect of PSB on CCL-mediated macrophage migration was assessed using Transwell assay. Network pharmacology analysis was performed to predict the key pathways that mediate the therapeutic effect of PSB. 2 10 3 1 2
RESULTS: In DSS-induced mouse models, PSB at 60 mg/kg optimally alleviated colitis, shown by reduced weight loss and DAI scores and increased colon length. PSB treatment significantly upregulated ZO-1 and claudin-1 expressions in the colon tissues, inhibited colonic macrophage infiltration, and promoted the shift of macrophage polarization from M1 to M2 type. In cultured intestinal epithelial cells, PSB significantly inhibited PI3K/AKT phosphorylation and suppressed chemokine CCLexpression. PSB treatment obviously blocked CCL-mediated macrophage migration of RAW264.7 cells, which could be reversed by exogenous CCL. Network pharmacology analysis and rescue experiments confirmed PI3K/AKT and CCLsignaling as the core targets of PSB. 2 2 2 2
CONCLUSIONS: PSB alleviates DSS-induced colitis in mice by targeting intestinal epithelial PI3K/AKT signaling, reducing CCLsecretion, and blocking macrophage chemotaxis and migration, highlighting the potential of PSB as a novel natural compound for treatment of inflammatory bowel disease. 2
