FIG. 7.

Effects of the xanthine oxidase inhibitor allopurinol on H. pylori-induced superoxide anion in Kato III cells. Cells were incubated with various concentrations of allopurinol (10 to 100 μM) for 1 h before stimulation with H. pylori strain 26695 at a ratio of bacteria to epithelial cells of 300:1. Superoxide anion was assessed by cytochrome c assay 30 min after stimulation. Each experiment was performed in triplicate. Values are means ± SEM of three separate experiments. *, P < 0.05 compared to control cells without allopurinol using a paired Student t test.