A PROTON PUMP INHIBITOR, E3810, HAS ANTIBACTERIAL ACTIVITY THROUGH BINDING TO HELICOBACTER-PYLORI

Helicobacter pylori infection is causally related to atrophic gastriti s, and it may also be associated with peptic ulcer and gastric carcino ma. Eradication of H. pylori is recommended in patients with such dise ases, especially in those with peptic ulcer. A new potent proton pump inhibitor, E3810, had an antibacterial effect on H. pylori, as has bee n reported for omeprazole and lansoprazole, two other proton pump inhi bitors. The minimum inhibitory concentration of E3810 was 1.57-3.13 mu g/ml, lower than that of omeprazole or lansoprazole. To clarify the m echanism of the antibacterial effect of E3810, we analyzed the charact eristics of E3810 binding to H. pylori. Scatchard plot analysis of thi s binding showed a curvilinear profile, indicating the presence of sev eral molecules with different affinities to E3810 on H. pylori. The bi nding capacity of E3810 to H. pylori was calculated to be about 2 x 10 (6) sites/cell. These results suggested that E3810 has an antibacteria l effect against H. pylori and that the effect may be mediated through direct binding to H. pylori.