Involvement of reactive oxygen species and high-voltage-activated calcium currents in nanoparticle zinc oxide-induced cytotoxicity in vitro

This study was to determine the possible neurotoxicity and mechanisms underlying the effects of nano-ZnO with sizes of 20-80 nm on central nervous system (CNS). The cytotoxicity of nano-ZnO was investigated in PC12 cells. The viability of cells was observed by a 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, and the generation of reactive oxygen species (ROS) for cells was evaluated by a fluorometry assay. The apoptosis of cells was detected and analyzed by flow cytometry. In addition, effects of nano-ZnO on the properties of high-voltage-activated (HVA) calcium currents were studied in acutely isolated rat hippocampal pyramidal neurons using the whole-cell patch clamp technique. The results of MTT assay showed that nano-ZnO (10 -4 g/mL) caused a significant decrease in cell