Nodakenin ameliorated TNBS-induced experimental colitis in mice by inhibiting intestinal epithelial cell pyroptosis

Abstract

Background and Aims Pyroptosis of intestinal epithelial cells is associated with intestinal barrier dysfunction and the intestinal inflammatory symptoms of Crohn's disease (CD). The natural plant monomer, nodakenin (Nod), inhibits NOD-like receptor protein 3 (NLRP3) expression, and this study aimed to evaluate its effect on CD-like colitis, as well as possible mechanisms. Methods Using TNBS intervention mice as CD animal models, the therapeutic effect of Nod on CD-like colitis in mice was explored through disease activity index (DAI) analysis, weight change, histological analysis, inflammatory factor expression and intestinal barrier function. In addition, the direct effect of Nod on the pyroptosis of intestinal epithelial cells was explored by immunofluorescence and western blot detection in LPS-/ATP-induced colon organoid models. Furthermore, through bioinformatics and in vivo and in vitro experimental verification, the potential mechanism by which Nod protects intestinal epithelial cells was explored. Results Nod intervention improved colitis and intestinal barrier function in TNBS-induced mice, as demonstrated by improvements in weight loss, DAI, tissue inflammation score, proinflammatory factor expression, and intestinal permeability. In addition, Nod inhibited the pyroptosis of intestinal epithelial cells in colitis mice and LPS-/ATP-induced colon organoids, as well as the expression of key pyroptosis regulators, such as NLRP3, GSDMD-N, and cleaved-caspase-1. Mechanistically, Nod inhibited the activation of PI3K/Akt signalling a in intestinal epithelial cells in TNBS-induced mice and LPS-/ATP-induced colonic organoids. Conclusions Nod restrained the pyroptosis of intestinal epithelial cells to protect the intestinal barrier of CD-like colitis by inhibiting PI3K/Akt signalling, this may provide a new option for the treatment of Crohn's disease.