Mechanistic investigation of toxicity of chromium oxide nanoparticles in murine fibrosarcoma cells

Chromium oxide nanoparticles (Cr(2)O(3)NPs) are widely used in polymers and paints. In the present study, we aimed to determine the toxicity of Cr(2)O(3)NPs in murine fibrosarcoma (L929) cells. The cytotoxicity of Cr(2)O(3)NPs was measured by MTT and neutral red uptake assays; Cr(2)O(3)NPs had significant cytotoxic effects on L929 cells. Enhancement of intracellular reactive oxygen species was observed in L929 cells after exposure to Cr(2)O(3)NPs. Cr(2)O(3)NPs produced caspase-3, indicating that exposure to Cr(2)O(3)NPs induced apoptosis. After exposure to Cr(2)O(3)NPs, the cellular glutathione level decreased and lipid peroxidation, superoxide dismutase, and catalase increased in a dose- and time-dependent manner. By using single-cell gel tests, we also observed increased DNA damage in a Cr(2)O(3)NP exposure-duration- and dose-dependent fashion. Cell toxicity and DNA damage may be useful biomarkers for determining the safety of Cr(2)O(3)NPs in human and animal health.