Antiadhesive property of microalgal polysaccharide extract on the binding of Helicobacter pylori to gastric mucin

• Published in: FEMS immunology and medical microbiology 2007-07, Vol.50 (2), p.231-238
• Main Authors: Loke, Mun Fai, Lui, Sook Yin, Ng, Bee Ling, Gong, Min, Ho, Bow
• Format: Article
• Language: English
• Subjects: Alkyl hydroperoxide reductase; Animals; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; antiadhesive; Antibiotic resistance; Antibiotics; Bacteria; Bacterial Adhesion - drug effects; Bacterial Proteins - metabolism; Bacteriology; Binding; Biological and medical sciences; Colonization; Colony Count, Microbial; Disease Models, Animal; Epithelial cells; Fundamental and applied biological sciences. Psychology; gastric mucin; Gastric Mucins - metabolism; Gastrointestinal diseases; Helicobacter Infections - drug therapy; Helicobacter Infections - prevention & control; Helicobacter pylori; Helicobacter pylori - drug effects; In vivo methods and tests; Life cycles; Mice; Mice, Inbred BALB C; Microalgae; microalgal polysaccharide; Microbial Viability; Microbiology; Miscellaneous; Mucin; Peroxidases - metabolism; Polysaccharides; Polysaccharides - isolation & purification; Polysaccharides - pharmacology; Protein Binding; Reductases; Saccharides; Spirulina; Spirulina - chemistry; Stomach - microbiology; Substrates; Urease; Urease - metabolism; Viability
• ISSN: 0928-8244; 1574-695X; 2049-632X
• DOI: 10.1111/j.1574-695X.2007.00248.x

The emergence of antibiotic-resistant Helicobacter pylori is of concern in the treatment of H. pylori-associated gastroduodenal diseases. As the organism was reported to bind gastric mucin, we used porcine gastric mucin as substrate to assess the antiadhesive property of polysaccharides derived from Spirulina (PS), a commercially available microalga, against the binding of H. pylori to gastric mucin. Results show that polysaccharides prevented H. pylori from binding to gastric mucin optimally at pH 2.0, without affecting the viability of either bacteria or gastric epithelial cells, thus favouring its antiadhesive action in a gastric environment. Using ligand overlay analysis, polysaccharide was demonstrated to bind H. pylori alkyl hydroperoxide reductase (AhpC) and urease, which have shown here to possess mucin-binding activity. An in vivo study demonstrated that bacteria load was reduced by >90% in BALB/c mice treated with either Spirulina or polysaccharides. It is thus suggested that polysaccharides may function as a potential antiadhesive agent against H. pylori colonization of gastric mucin.