Inflammatory bowel disease (IBD) in humans is closely related to bacterial infection and the disruption of the intestinal barrier. Paeoniflorin (PF), a bioactive compound from Paeonia lactiflora Pallas plants, exerts a potential effect of anti-inflammatory reported in various researches. However, the effect of PF on intestinal barrier function and its related mechanisms has not been identified. Here, we investigate the PF potential anti-inflammatory effect on lipopolysaccharide (LPS)-stimulated human Caco-2 cell monolayers and explore its underlying key molecular mechanism. In this context, PF significantly increased TEER value, decreased intestinal epithelium FITC-dextran flux permeability, and restored the expressions of occludin, ZO-1, and claudin5 in LPS-induced Caco-2 cell. In vitro, treatment of PF significantly inhibited LPS-induced expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), and matrix metalloproteinase-9 (MMP-9). In addition, we found that PF suppressed nuclear factor kappa B (NF-κB) signaling via activating the Nrf2/HO-1 signaling pathways in ILPS-stimulated Caco-2 cells. Our findings indicate that PF has an inhibitory effect on endothelial injury. Our findings suggested that PF has an anti-inflammatory effect in ILPS-stimulated Caco-2 cells, which might be a potential therapeutic agent against IBD and intestinal inflammation.
Keywords: NF-κB; Nrf2/OH-1; intestinal barrier; paeoniflorin; tight junction protein.