Lycium barbarumpolysaccharides ameliorate intestinal barrier dysfunction and inflammation through the MLCK-MLC signaling pathway in Caco-2 cells

Impairment of the intestinal barrier often occurs in inflammatory bowel diseases, and pro-inflammatory factors play a vital role in the pathogenesis of intestinal diseases. In our study, the potential protective effects ofLycium barbarumpolysaccharides (LBP) against intestinal barrier dysfunction evoked by pro-inflammatory factors and its anti-inflammatory effects were investigated. Caco-2 cells were stimulated with or without tumor necrosis factor (TNF)-alpha in the presence or absence of LBP. Our findings showed that LBP assuaged the increase of paracellular permeability and the decrease of transepithelial electrical resistance (TER) in Caco-2 cells. In addition, LBP also prevented the secretion of pro-inflammatory markers (IL-8, IL-6, ICAM-1 and MCP-1) in TNF-alpha-challenged Caco-2 cells. Moreover, LBP inhibited the overexpression of tight junction (TJ) proteins (claudin-1, ZO-3, and occludin) and the increase of MLCK, pMLC, p-I kappa B alpha and NF kappa Bp65 protein expression evoked by TNF-alpha was suppressed by LBP pre-incubation. This finding indicated that LBP improve TNF-alpha-evoked intestinal barrier dysfunctionviasuppressing the MLCK-MLC signaling pathway mediated by NF kappa B.