Titanium dioxide nanoparticles induced reactive oxygen species (ROS) related changes of metabolomics signatures in human normal bronchial epithelial (BEAS-2B) cells

Titanium dioxide often enters the respiratory tract in the form of nano-dust in occupational sites. Metabolomics may be a promising method for studying the toxicology of nano titanium dioxide. The intention of this study was to explore the possible impact of titanium dioxide nanoparticles (TiO 2 NPs) on the metabolomics signatures of human normal bronchial epithelial (BEAS-2B) cells and to search for investigate the role of reactive oxygen species (ROS). In this study, BEAS-2B cells were treated by TiO 2 NPs (0, 25, 50 and 100 μg/mL) for 48 h. The metabolites extracted from BEAS-2B cells were determined by untargeted metabolomics technique, and the differential metabolites and metabolic pathways were discovered by using multivariate analysis. Intracellular ROS was detected by DCFH-DA probe and flow cytometry method. Machine learning was used to explore the relationship between ROS and metabolomics changes. Totally, seventy-six differential metabolites and the steroid biosynthesis pathway of BEAS-2B cells were observed after treatment of TiO 2 NPs. Lipid and lipid-like metabolites were the most significant classes among the metabolite products induced by TiO 2 NPs. TiO 2 NPs resulted in a dose-dependent increase in intracellular ROS levels, and correlated with most of the differential metabolites. In conclusion, TiO 2 NPs increased the level of the oxidative stress, which could contribute to the altered signature represented by lipid metabolism in BEAS-2B cells. • TiO 2 NPs change the metabolomics signatures in BEAS-2B cells even at low dose. • TiO 2 NPs affect lipid and lipid-like molecules, especially the steroid biosynthesis. • ROS is related to metabolomics changes caused by TiO 2 NPs.