Effect of sucralfate on the degradation of human gastric mucus by Helicobacter pylori protease and lipases.

Abstract

Among the factors implicated in the weakening of mucus perimeter of gastric mucosal defense is Helicobacter pylori, the pathogenic action of which appears to be exerted through the elaborated protease and lipase enzymes. We present evidence that the activities of these enzymes are inhibited by an antiulcer agent, sucralfate. The grown colonies of bacteria were washed with saline, filtered through sterilization filter, and the filtrate used as the enzyme source. In the absence of sucralfate, the H. pylori protease caused extensive degradation of human gastric mucus protein, whereas free fatty acids, glycerol monooleate and lysophatidylcholine, were produced by the action of H. pylori lipase and phospholipase A enzymes. Introduction of sucralfate to the incubation systems led to the reduction in the rate of mucus protein and lipid degradation. The rate of proteolysis inhibition was proportional to sucralfate concentration up to 90 micrograms/ml, at which point a 32.5% reduction in mucus degradation was obtained, whereas the maximum inhibition of lipase (35.5%) and phospholipase A (48%) activities occurred at sucralfate concentration of 200 micrograms/ml. The results demonstrate that sucralfate is capable of counteracting in vitro the mucolytic activity of H. pylori toward human gastric mucus proteins and lipids.