Effect of Zirconium Dioxide Nanoparticles on Glutathione Peroxidase Enzyme in PC12 and N2a Cell Lines

Today, special attention is paid to the use of zirconium dioxide nanoparticle (nano-zro2), a neutral bioceramic metal, particularly for drug and gene delivery in medicine. however, there are some reports implying that use of nano-zro2 is associated with cytotoxic effects like inhibiting the cell proliferation, dna damage and apoptosis. in the present study, we examined whether nano-zro2 alters cell viability and glutathione peroxidase (gpx) activity in two neuronal cell lines. the pc12 and n2a cells were cultured in the absence or presence of varying concentrations (31.25-2000 μg/ml) of nano-zro2 for 12, 24 or 48 h. the cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2h-tetrazolium (mts) assay and gpx activity was determined by quantifying the rate of oxidation of the reduced glutathione to the oxidized glutathione. nano-zro2 caused a significant reduction in cell viability and gpx activity after 12, 24 and 48 h, as compared with control group. these effects were concentration dependent and started from 250 μg/ml. the present study demonstrated that nano-zro2, at concentrations of > 250 μg/ml, has antiproliferative effects via reducing the cell defense mechanism against oxidative stress.