Figure 1.

H. pylori induces DNA damage and increases the ROS level in gastric epithelial cells (GES-1) cells, but pretreatment with NAC protects cells from oxidative damage. (a) At 6 h of culture, DNA damage was examined using comet formation assay, scale bar = 200 μm. (b) ROS levels were determined by measuring the level of fluorescent DCF; ^∗∗p < 0.01 compared to the control group. (c) Comet formation was quantitatively assessed according to the relative tail moment at 6 h of culture; ^∗∗p < 0.01.