FIG. 6.

Effects of antioxidants on H. pylori-induced ROS production in Kato III cells. DCFH₂-DA-loaded Kato III cells were treated with various antioxidants or media alone 1 h before stimulation with H. pylori strain 26695 at a ratio of bacteria to epithelial cells of 300:1. Antioxidants tested in these experiments were 10 mM GSH, 50 mM DMTU, 5 mM DESF, and DTPA. Data are depicted as mean levels of DCF fluorescence 30 min after stimulation with H. pylori in untreated cells (H. pylori) or in antioxidant-treated cells (H. pylori + drug), as percentages of values for uninfected, untreated control cells, ± SEM (n = 3 or 4 experiments). The effects of drugs alone are also shown. *, P < 0.05; **, P < 0.01 (compared to H. pylori alone using a paired Student t test).