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 PM2.5) increases the risk of nasal lesions, but the underlying molecular mechanism has not been fully elucidated. In the atmosphere, the composition of PM2.5 collected varies in physical and chemical properties, which affects its damage to human health. Thus, we constructed artificial PM2.5 particles based on actual PM2.5 and investigated the in vivo effects of artificial PM2.5 exposure on the oxidative stress, inflammatory response, and nasal mucosa morphology of rats. The results showed that artificial PM2.5 is comparable in composition ratio, size, and morphology to actual PM2.5. This in vivo study indicated that artificial PM2.5 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 PM2.5 particles could be used for experimental study of PM2.5 toxicology, ensuring that the physical and chemical properties of experimental PM2.5 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 PM2.5.