Helicobacter pylori urease activity is toxic to human gastric epithelial cells

A human gastric adenocarcinoma cell line was used to evaluate the contribution of urease from Helicobacter (formerly Campylobacter) pylori to its cytotoxicity. Gastric cells cultured in medium supplemented with 20 mM urea were exposed to 5 x 10⁶ CFU of H. pylori per ml with or without the addition of a urease inhibitor, acetohydroxamic acid. Viabilities of cells exposed to H. pylori for 2, 24, and 48 h, assessed by incorporation of neutral red dye, were 60, 27, and 16%, respectively; however, the viabilities of cells exposed to both H. pylori and acetohydroxamic acid were 92, 46, and 20% after 2, 24, and 48 h, respectively, (P < 0.001). Therefore, the urease activity of H. pylori may play an important role in its pathogenicity, and inhibition of this enzyme activity may have therapeutic potential.