Figure 4. Oxidative stress following MF exposure. G401 and A549 cells were subjected to MF exposure for 0.5, 1 or 1.5 h. (A) MDA content as indicator of lipid peroxidation. (B) NADPH content as indicator of antioxidative capacity. Data are expressed as mean ± SE from 3 independent experiments (n=5 in each experiment). *: P<0.05; **: P<0.01.