In Vitro Evaluation of the Protective Role of Lactobacillus StrainsAgainst Inorganic Arsenic Toxicity

Inorganic arsenic [iAs, As(III) + As(V)] is considered a human carcinogen. Recent studies show that it has also toxic effects on the intestinal epithelium which might partly explain its systemic toxicity. The aim of this study is to evaluate the protective role of lactic acid bacteria (LAB) against the toxic effects of iAs on the intestinal epithelium. For this purpose, the human colonic cells Caco-2 were exposed to As(III) in the presence of various LAB strains or their conditioned medium. Results showed that some strains and their conditioned media partially revert the oxidative stress, the production of pro-inflammatory cytokines, the alterations of the distribution of tight junction proteins, and the cell permeability increases caused by As(III). These results show that both soluble factors secreted or resulting from LAB metabolism and cell-cell interactions are possibly involved in the beneficial effects. Therefore, some LAB strains have potential as protective agents against iAs intestinal barrier disruption.