Cobalt oxide (Co3O4) nanoparticles induced genotoxicity in Chinese hamster lung fibroblast (V79) cells through modulation of reactive oxygen species.

Incessant production, pervasive applications in different fields, and eventually unintended exposure of cobalt oxide nanoparticles (Co3O4 NPs) lead to rise in their toxicity studies toward human health. However, the information regarding the potential toxicity mechanisms of Co3O4 NPs especially genotoxicity is still sparse with missing interconnections. So far, only solitary reports on Co3O4 NPs are at hand, bearing witness to reactive oxygen species (ROS)-mediated DNA damage in lung cells. To address this, we evaluated the Co3O4 NP-induced cytotoxic and genotoxic potential in Chinese hamster lung fibroblast cell line (V79). Our preliminary results demonstrate that Co3O4 NPs at concentrations of 20-100 µg/ml induced moderate mortality after 24-h exposure. However, these low concentrations caused a significant reduction in various organelles' activity in a concentration-dependent manner. Mitochondrial activity and membrane potential were found to be compromised due to NP exposure in a concentration-dependent manner. The study affirms that Co3O4 NPs inhibited lysosomal activity in V79 cells. In addition to this, Co3O4 NPs are also found to stimulate free oxygen radical generation. Genotoxicity studies revealed a potent and dose-dependent effect of non-cytotoxic concentrations of Co3O4 NPs in the induction of DNA lesions. Interestingly, N-acetylcysteine, a free oxygen radical scavenger (5, 10 mM, pretreatment) inhibited the progression of free oxygen radicals and induction of Co3O4 NP-mediated DNA lesions. This suggests the ROS-mediated genotoxic potential of Co3O4 NPs.