Total polysaccharide of adlay bran (Coix lachryma-jobi L.) improves TNF-α induced epithelial barrier dysfunction in caco-2 cells via inhibition of inflammatory response

The present research was carried out to investigate the protective effect of total polysaccharides of adlay bran (TPA) on TNF-α-evoked epithelial barrier dysfunction in caco-2 cells. Caco-2 cells were treated with or without TPA in the absence or presence of TNF-α, and transepithelial electrical resistance (TEER) and phenol red flux were assayed to evaluate the intestinal epithelial barrier function. The results indicated that TPA suppressed TNF-α-induced release of pro-inflammatory factors. Furthermore, TPA obviously assuaged both the increased paracellular permeability and the decrease of TEER in TNF-α-challenged Caco-2 cells. Furthermore, TPA obviously assuaged TNF-α-evoked up-regulation of the IL-8 and IL-6 expression, down-regulation of occludin and ZO-3 expression, and markedly suppressed the activation and protein expression of NF-κB p65. Our results indicated that TPA assuages the TNF-α-evoked dysfunction of the intestinal epithelial barrier by inhibiting NF-κB p65-mediated inflammatory response.