Toxicological Effects of Artificial Fine Particulate Matter in Rats through Induction of Oxidative Stress and Inflammation.

Airborne fine particulate matter with an aerodynamic diameter equal to or smaller than 2.5 μm (abbreviated as PM) increases the risk of nasal lesions, but the underlying molecular mechanism has not been fully elucidated. In the atmosphere, the composition of PM collected varies in physical and chemical properties, which affects its damage to human health. Thus, we constructed artificial PM particles based on actual PM and investigated the in vivo effects of artificial PM exposure on the oxidative stress, inflammatory response, and nasal mucosa morphology of rats. The results showed that artificial PM is comparable in composition ratio, size, and morphology to actual PM. This in vivo study indicated that artificial PM exposure reduces total superoxide dismutase and glutathione peroxidase activities, elevates malondialdehyde content in the nasal mucosa, and induces increased levels of pro-inflammatory mediators, including interleukin-1, interleukin-6 and tumor necrosis factor-α. Our data shows that artificial PM particles could be used for experimental study of PM toxicology, ensuring that the physical and chemical properties of experimental PM are relatively constant and allowing for repeatability of this research. Oxidative damage and inflammatory response may be the toxic mechanisms that cause nasal lesions after exposure to artificial PM.