The hidden face of nitrogen oxides species: from toxic effects to potential cure?

Nitrogen oxides species (NOx) represent one of the most threatening air pollutant due to their prevalence and harmful impact on environment and human health. The term NOx gather mainly nitric oxide (NO) and nitrogen dioxide (NO2), mostly produced by anthropogenic activities such as transport and industries. Several cellular constituents were already described as NOx targets. This includes membranes, proteins, respiratory chain enzymes, lipids and DNA. Such damages lead to pathologies of lungs, cardiovascular system and skin since these organs represent the first barrier towards the environment. On the other hand, NOx are also naturally synthetized by several organisms, playing a mediator role in essential cellular functions. However, few data are yet available on NOx activity towards microorganisms. Here, we review data concerning the double face of NOx, including their use in the medical field against pathogens’ infection that highlight the versatility of these compounds.