[Niranthin ameliorates Crohn's disease-like enteritis in mice by inhibiting intestinal epithelial cell apoptosis and protecting intestinal barrier via modulating p38/JNK signaling].

OBJECTIVES: To investigate the therapeutic effect of the natural compound niranthin on Crohn's disease-like colitis in mice and explore the underlying molecular mechanisms. METHODS: In a mouse model of colitis induced by 2,4,6-trinitro-benzenesulfonic acid (TNBS), the therapeutic effect of niranthin was evaluated by observing the changes in body weight, disease activity index (DAI), and colon length of the mice. The levels of inflammatory cytokines (IL-6, IL-1β, TNF-α, IL-17A and IL-10) in the intestinal mucosal tissue were detected using ELISA and quantitative real-time PCR (qRT-PCR). TUNEL staining and Western blotting were used to assess intestinal epithelial cell apoptosis and the expressions of Bcl-2 and Bax. The expression levels of tight junction proteins (ZO-1 and claudin-1) and the activation of the p38/JNK signaling pathway were investigated using Western blotting, and diprovocim intervention experiments were conducted to explore the molecular regulatory mechanism of niranthin. RESULTS: Niranthin treatment significantly increased body weight of TNBS-treated mice, lowered the DAI and histological inflammation scores, and increased colon length of the mice. The niranthin-treated mouse models showed obviously reduced protein and mRNA levels of IL-6, IL-1β, IL-17A, and TNF-α and upregulated expression of IL-10 in the colon tissue. TUNEL staining and Western blotting demonstrated that niranthin significantly inhibited intestinal epithelial cell apoptosis and activated the anti-apoptotic pathway in the mouse models. Niranthin treatment obviously upregulated the expression levels of ZO-1 and claudin-1 and downregulated the phosphorylation levels of p38 and JNK in the colon tissues of the mice. Diprovocim intervention obviously attenuated the inactivation of the p38/JNK signaling pathway induced by niranthin in the mouse models. CONCLUSIONS: Niranthin ameliorates TNBS-induced Crohn's disease-like colitis in mice by inhibiting intestinal epithelial cell apoptosis and protecting the integrity of the intestinal barrier via regulating the activation of the p38/JNK signaling pathway.