Exposure to Atrazine Induces Lung Inflammation through Nrf2-HO1 and Beclin 1/LC3 Pathways

Atrazine (ATR) is the second most widely used herbicide, after glyphosate, that is used to stop pre- and post-emergence broadleaf and grassy weeds. In 2007, it was included in the class of endocrine disruptors due to the impact its exposure had on human health. Occasional ATR exposure at work has been linked to an increased risk of respiratory problems, but the molecular mechanisms underlying this relationship has not yet been fully elucidated.

Mice were exposed to an aerosol containing ATR. In particular ATR aerosol was prepared by dissolving 250 mg of ATR in a vehicle made with saline and 10% DMSO. Seven days after the aerosol exposure, the mice were sacrificed and lung tissue, bronchoalveolar lavage fluid (BALF), and blood samples were collected for histology and biochemical analysis.

ATR inhalation induces a generalized state of oxidative/nitrosative stress that leads to an increase in cytokines production and to a physiologically unstable antioxidant defense response evaluated by the alteration of Nrf-2 pathways. Moreover, it stimulates autophagy through Beclin 1/Lc3 expressions and increases lipid peroxidation and apoptosis. All these effects culminate in serious alterations in the tissue architecture of the lungs and to an increase in mucus production and mast cells degranulation.

Our study shows, for the first time, the impact of ATR inhalation on lung tissue. This could represent the first step to also recognize this substance as a problematic air pollutant as well as a soil and water contaminant.