Abstract
OBJECTIVES: To investigate the effect of hypaphorine (HYP) on Crohn's disease (CD)‑like colitis in mice and its molecular mechanism. METHODS: Thirty male C57BL/6J mice were equally randomized into WT, TNBS, and HYP groups, and in the latter two groups, mouse models of CD-like colitis were established using TNBS with daily gavage of 15 mg/kg HYP or an equivalent volume of saline. The treatment efficacy was evaluated by assessing the disease activity index (DAI), body weight changes, colon length and histopathology. The effect of HYP was also tested in a LPS-stimulated Caco-2 cell model mimicking intestinal inflammation by evaluating inflammatory responses and barrier function of the cells using qRT-PCR and immunofluorescence staining. GO and KEGG analyses were conducted to explore the therapeutic mechanism of HYP, which was validated in both the cell and mouse models using Western blotting. RESULTS: In the mouse models of CD-like colitis, HYP intervention obviously alleviated colitis as shown by significantly reduced body weight loss, colon shortening, DAI and inflammation scores, and expressions of pro-inflammatory factors in the colon tissues. HYP treatment also significantly increased the TEER values, reduced bacterial translocation to the mesenteric lymph nodes, liver, and spleen, lowered serum levels of I-FABP and FITC-dextran, increased the number of colonic tissue cup cells, and upregulated colonic expressions of MUC2 and tight junction proteins (claudin-1 and ZO-1) in the mouse models. In LPS-stimulated Caco-2 cells, HYP treatment significantly inhibited the expressions of pro-inflammatory factors and increased the expressions of tight junction proteins. Western blotting showed that HYP downregulated the expressions of the key proteins in the TLR4/MyD88 signaling pathway in both the in vitro and in vivo models. CONCLUSIONS: HYP alleviates CD-like colitis in mice possibly by suppressing intestinal epithelial inflammation and improving gut barrier function.