Inhibition of Helicobacter pylori adhesion to Kato III cells by intact and low molecular weight acharan sulfate

We investigated the inhibitory activity of glycosaminoglycans (GAGs) in terms of growth, adhesion, and VacA vacuolation of Helicobacter pylori. Intact acharan sulfate (AS, MW:114 kDa) potently inhibited H. pylori adhesion to Kato III cells with IC50 value of 1.4 mg/mL, while other GAGs did not show any inhibitory activity except for heparin which is a well-known inhibitor of H. pylori adhesion. To investigate whether low molecular weight acharan sulfate (LMWAS) can inhibit H. pylori adhesion, we performed chemical depolymerization of AS by radical reactions to obtain LMWAS. Its physicochemical properties were characterized by high-performance size exclusion chromatography (HPSEC), agarose gel electrophoresis, disaccharide compositional analysis after digestion with heparinase II, and H-1-NMR spectroscopy. The most potent molecular size of LMWAS was 3 kDa with IC50 value of 32 mu g/mL, which is 44-fold more potent than intact AS. These results suggest that AS as well as other GAGs can be chemically depolymerized by free radicals and LMWAS compared to intact AS can be applied as a pharmaceutical candidate in order to inhibit H. pylori adhesion to Kato III cells.