Comparison of the effects of titanium dioxide and zinc oxide nanoparticles on glutathione reductase enzyme activities

In this study, baker's yeast (Saccharomyces cerevisiae) glutathione reductase (GR) were exposed to 0, 25, 50, 100, 250 and 500 mg/L (ppm) concentrations of titanium dioxide nanoparticles (TiO2 NPs) and zinc oxide nanoparticles (ZnO NPs) in vitro. Percentage changes in glutathione reductase enzyme activity under the effect of 25, 50, 100, 250 and 500 ppm TiO2 NPs were -3.12 ; -0.87 ; -2.12 ; -2.12 and -1.50 respectively. Percentage changes in glutathione reductase enzyme activity under the influence of 25, 50, 100, 250 and 500 ppm ZnO NPs were -2.01 ; +1.88 ; +0.38 ; -2.51 and +0.75 respectively. In this study, it was observed that when the concentrations of TiO2 NPs and ZnO NPs were increased, there was no statistically significant change in GR enzyme activities compared to the control groups (p > 0.05, N=3). In conclusion, TiO2 and ZnO NPs did not exert any inhibition on GR.