effect of zirconium dioxide nanoparticles on glutathione peroxidase enzyme in pc12 and n2a cell lines

objective: 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.materials and methods: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. results: nano-zro2 caused a significant reduction in cell viability and gpx activity after 12, 24 and 48h, as compared with control group. these effects were concentration dependent and started from 250µg/ml.conclusion: 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.