Genotoxicity of nanoscale zerovalent iron particles in tobacco BY-2 cells

Nanoremediation by direct injection of nZVI into contaminated water or soil has engendered their liberation into the environment facilitating interaction with plant systems. Available reports display a scarcity of information on the genotoxicity of nZVI in plants. In this study, the cyto-genotoxic potential of nZVI was evaluated in tobacco BY-2 cells treated for 24 h. A wide range of concentrations from 5 to 500 µg/mL of nZVI were tested for cytotoxicity and for other assays a maximum concentration of 20 µg/mL was used. Cytotoxicity assessed by TTC and Evans Blue tests showed maximum cell death in cells treated with the lowest concentration of nZVI (5 µg/mL). Comet assay confirmed high DNA damage at low concentrations, which corroborated with high accumulation of nZVI as observed by Prussian blue staining. Qualitative and quantitative estimation of ROS confirmed the accumulation of superoxide anions, hydroxyl, peroxyl radicals and hydrogen peroxide upon treatment with low concentrations of nZVI. Taken together, this study confirmed ROS mediated cytotoxicity and genotoxicity of nZVI and unravels further prospects in the safety evaluation of nZVI as well as the toxicity testing of other nanomaterials of ecotoxicological relevance.