Decomposition of dextran sulfate sodium under alkaline, acidic, high temperature and high pressure conditions

Abstract

The pathogenic mechanisms responsible for inflammatory bowel disease (IBD) are poorly understood. In an IBD animal model, the oral administration of polysaccharides such as dextran sulfate sodium (DSS) induced colitis, which exhibited several clinical and histological features similar to IBD. However, pathogenic factors in the development of colitis remain unclear, as do the chemical properties of DSS. Therefore, we investigated the chemical properties of DSS in this study. DSS reacted under 1 N acidic or alkaline conditions, and the reactants were analyzed using size exclusion and ion chromatography. The reactants were also analyzed in terms of metachromasia as a peculiarity of sulfated polysaccharides. DSS was depolymerized to a Mr 2500 moiety under acidic, but not under alkaline conditions. Sulfate was depleted from DSS under alkaline conditions (30%), but less so under acidic conditions (10%). In addition, autoclave treatment induced depolymerization to a Mr 1800 moiety and depleted the sulfate. This depolymerized DSS under acidic conditions has as many sulfates as a native DSS molecule with a Mr of 5000, exhibiting metachromasia as a peculiarity of sulfated polysaccharides. Therefore, these Mr 2500 or 1800 DSS molecules may be useful in investigating the mechanisms of DSS-induced colitis.