In vitro toxicological effects of particulate matter from Metropolitan Region of Vitoria, Brazil

Abstract

<b>Introduction:</b> Air pollution is an environmental risk to respiratory diseases involving molecular and cellular mechanisms. <b>Aim:</b> To investigate the <i>in vitro</i> cytotoxic and pro-inflammatory effects of particulate matter (PM) of&nbsp;six monitoring stations from the Metropolitan Region of Vitória (MRV), Espirito Santo, Brazil. <b>Methods:</b> PM was chemically characterized by inductively coupled plasm spectrometry and a direct mercury analyzer. <i>In vitro</i> cytotoxic effects of PM (3.12 to 200 µg/mL) were determined in human lung epithelial cells (A549), and macrophage (RAW 264.7) by MTT assay. Pro-inflammatory effects of PM were estimated by their influence on the production of nitric oxide (NO), superoxide anion (O2•-), proinflammatory cytokines tumor necrosis factor (TNF-α), interleukin 6 (IL-6), and activation of nuclear factor kappa B (NF-B). Genotoxicity was evaluated by the comet assay. Cell cycle, oxidative stress (DCF and DHE), and apoptosis were analyzed by flow cytometry. Statistical comparisons were carried out using ANOVA followed by Tukey’s post hoc test (p&lt;0.05). <b>Results:</b> Chemical analysis of PM revealed aluminum and iron as the major chemical elements in all monitoring stations. Mercury was also present in higher concentrations compared to international references. The <i>in vitro</i> results showed that PM presents a dose-dependent cytotoxic effect in macrophage and A549 cell lines. The PM increased the production of NO, O2•-, and TNF-α and IL-6. PM&nbsp;altered cell cycle, increased apoptosis frequency, and DNA damage. Moreover, PM increased the expression NFΚB. Besides, a positive correlation between Al and Fe and ROS production was observed. <b>Conclusion:</b> PM might&nbsp;be deleterious to human health.