Oxidative stress and apoptosis induced by hydroxyapatite nanoparticles in C6 cells.

Hydroxyapatite (HA) nanoparticles have been reported to exhibit anti-tumor effects on various human cancers, but the effects of HA on glioma cells remain unclear. The aim of this study was to explore whether HA can inhibit the proliferation and induce the apoptosis of C6 cells. Use of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that HA induced C6 cell death in a concentration-dependent and time-dependent manner. Results from hoechst 33342 staining and flow cytometry assay showed that HA induced C6 cell apoptosis significantly. Meanwhile, the flow cytometric assay gave clear indication that HA induced intracellular accumulation of reactive oxygen species (ROS). The measurement of superoxide dismutase (SOD) generation showed that HA decreased the total SOD of cellular levels. Interestingly, pretreatment of N-(mercaptopropionyl)-glycine (N-MPG), known as a type of ROS scavenger formulations, could somehow inhibit C6 cell apoptosis induced by HA. These results may provide potential anti-glioma treatment in the future.