Figure 6. Oxidative stress in TM-4 cells treated with TiO2-NPs. (A) Intracellular CAT activity in TM-4 cells treated with TiO2-NPs for 24 h. (B) Intracellular hydrogen peroxide levels in TM-4 cells treated with TiO2-NPs for 24 h. The results are expressed as the mean ± SEM. n=7, *p<0.05, **p<0.01 compared to the control.