Toxicity assessment of magnesium oxide nano and microparticles on cancer and non-cancer cell lines

Testing of magnesium oxide nanoparticles (MgO NPs) on established cell lines at cellular levels using toxicological endpoints provide valuable information about their adverse effects upon exposure. In vitro toxicity assessment of MgO NPs and their microparticles was carried out at 50, 100, 200 and 400 µg/mL concentrations by using cytotoxicity, genotoxicity, oxidative stress, cellular apoptosis and cellular uptake studies in cancer (HepG2) and non-cancer (NRK 49F) cell lines after 24 h of treatment. IC50 concentration for MgO NPs was found to be > 400 µg/mL in both cell lines after 24 h treatment. A concentration dependent toxicity was noted in genotoxic studies and oxidative stress parameters. A significant increase in the comet tail DNA was recorded at 200 and 400 µg/mL concentrations of MgO NPs when compared with controls in HepG2 and NRK 49F cells. Exposure to MgO NPs led to an increase in the generation of reactive oxygen species (ROS) in both the cell types. Genotoxicity results were further supported by apoptotic analysis. MgO particles were found adhered to the cell membrane when assayed by ICP-OES. The results of this study showed that the MgO NPs were toxic at high concentrations only. Furthermore, MgO NPs are more toxic to cancerous cells compared to non-cancerous cells. ROS mediated genotoxicity was observed when treated with MgO NPs. The current study adds to the information on MgO particles. The results of this investigation may help in advancement of understanding of toxicological nature of MgO NPs and aid in their use.