Nitrogen contaminants damage on intestinal epithelial tight junctions: a review

During food digestion, the intestinal epithelial barrier is essential for health. The intestinal epithelial is typically maintained by normal tight junctions. Barrier dysfunction and increased permeability have been observed for many diseases and, more recently, after ingestion of nitrogen contaminants such as nitrogen heterocycles, amine, and nitro. Mechanisms by which these contaminants disrupt the intestinal epithelial barrier remain poorly understood. Here, we review the chemical disruption of intestinal epithelium permeability of tight junction proteins, to propose a common mechanism involving the production of reactive oxygen species (ROS) followed by inflammation. Specifically, nitrogen-containing chemicals promote ROS generation, which disrupts the activity of the metabolic enzyme cytochrome P450s, leading to the activation of nicotinamide adenine dinucleotide phosphate oxidase.