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

AIM To determine whether Lactobacillus plantarum can modify the deleterious effects of tumor necrosis factor-alpha (TNF-alpha) 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-IkappaB-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 IkappaB-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.