Anti-adhesive effect of an acidic polysaccharide from Aloe vera L. var. chinensis (Haw.) Berger on the binding of Helicobacter pylori to the MKN-45 cell line

Objectives The emergence of antibiotic-resistant Helicobacter pylori strains has necessitated a search for alternative therapies for the treatment of this infection. The aim of this study was to evaluate whether or not polysaccharide fractions from Aloe vera are effective in inhibiting the adherence of H. pylori in vitro. Methods Polysaccharide fractions were extracted from A. vera and subjected to carbohydrate analysis. The adhesive effect was determined by co-incubation of H. pylori and cells with polysaccharides followed by fluorescein isothiocyanate labelling and Gram staining in vitro. Inhibition of H. pylori growth and cellular viability was tested by agar diffusion and MTT assay. Key findings APS-F2 contained significant amounts of galacturonic acid, galactose and arabinose. APS-F1 was galacturonic acid-free and consisted of mannose, glucose and galactose. APS-F2 (0.1, 0.5 and 1.0 mg/ml) reduced the count of H. pylori attached to MKN45 cells to 88, 76 and 64%, respectively. APS-F1 did not show the same effect. Neither polysaccharide revealed an inhibitory effect on the growth of H. pylori or cell viability. In addition, APS-F2 was shown to have a potent anti-adhesive effect against Escherichia coli. Conclusions The results show that the acidic polysaccharide from A. vera has a potent anti-adhesive effect against H. pylori in vitro. However, there have yet to be any in-vivo studies to demonstrate the clinical relevance of this finding.