A Novel Action of the Proton Pump Inhibitor Rabeprazole and Its Thioether Derivative against the Motility of Helicobacter pylori

The motility of Helicobacter pylori was maximum at 37°C and at pH 6. A newly developed proton pump inhibitor, rabeprazole (RPZ), and its thioether derivative (RPZ-TH) markedly inhibited the motility of H. pylori. The concentrations of the drug necessary to inhibit 50% of the motility were 0.25, 16, 16, and >64 μg/ml for RPZ-TH, RPZ, lansoprazole, and omeprazole, respectively. No such inhibitory effects were observed with H(2) blockers or anti-H. pylori agents. The motilities of Campylobacter jejuni and C. coli—but not those of Vibrio cholerae O1 and O139, Vibrio parahaemolyticus, Salmonella enterica serovar Typhimurium, and Proteus mirabilis—were also inhibited. Prolonged incubation with RPZ or RPZ-TH inhibited bacterial growth of only H. pylori, except for a turbid colony mutant. The results indicate that RPZ and RPZ-TH have a characteristic inhibitory effect against the motility of H. pylori (spiral-shaped bacteria), which is distinguished from that against bacterial growth.