Glycopeptide derived from soybean β-conglycinin inhibits the adhesion of Escherichia coli and Salmonella to human intestinal cells

Glycopeptide, a compound utilized as a medicinal ingredient, was prepared through size exclusion chromatography following the alcalase digestion of soybean β-conglycinin. In vitro, experiments were conducted by using the LoVo (human colon adenocarcinoma) cell line to confirm if soybean glycopeptides, when applied to enteropathogens (Escherichia coli serotype O114, O111, Salmonella typhimurium, S. enteritidis), could produce an anti-adhesive effect on human intestinal cells. The results indicated that 0.5 mg mL−1 and 1.0 mg mL−1 of soybean glycopeptide can significantly inhibit the adhesion of the four bacteria strains to LoVo cells (S. typhimurium P < 0.05; S. enteritidis, E. coli O114 and E. coli O111 P < 0.01). The assay of lactate dehydrogenase (LDH) release revealed that soybean glycopeptide was effective in preventing the damage of the LoVo cells plasma membrane caused by bacterial infection. Soybean glycopeptide did not show inhibitory effects on bacterial growth in vitro. It was assumed that mannose substructure of soybean glycopeptide recognized by the bacteria block the adhesion of bacterial to LoVo cells. Based on these properties, soybean glycopeptide has the potential to be an effective ingredient with a protective effect against E. coli and Salmonellae infection.