Lactobacillus plantarum inhibits epithelial barrier dysfunction and interleukin-8 secretion induced by tumor necrosis factor-α

AIM: To determine whether Lactobacillus plantarum can modify the deleterious effects of tumor necrosis factor-a (TNF-a) on intestinal epithelial cells. METHODS: Caco-2 cells were incubated with TNF-alpha alone or in the presence of L. plantarum. Transepithelial electrical resistance was used to measure epithelial barrier function. Interleukin 8 (IL-8) secretion by intestinal epithelial cells was measured using an ELISA. Cellular lysate proteins were immunoblotted using the anti-extracellular regulated kinase (ERK), anti-phospho-ERK and anti-I kappa B-alpha. RESULTS: A TNF-alpha-induced decrease in transepithelial electrical resistance was inhibited by L. plantarum. TNF-alpha-induced IL-8 secretion was reduced by L. plantarum. L. plantarum inhibited the activation of ERK and the degradation of I kappa B-alpha in TNF-alpha-treated Caco-2 cells. CONCLUSION: Induction of epithelial barrier dysfunction and IL-8 secretion by TNF-alpha is inhibited by L. plantarum. Probiotics may preserve epithelial barrier function and inhibit the inflammatory response by altering the signal transduction pathway. (C) 2007 The WJG Press. All rights reserved.