Inhibition of adhesion of Neisseria meningitidis to human epithelial cells by berry juice polyphenolic fractions

Abstract

The adhesion of pathogens to host tissues is the requirement for the initiation of the majority of infectious diseases. It was shown recently that the binding of Neisseria meningitidis pili to immobilized human epithelial cells is inhibited by molecular size fractions (10–100 kDa) of berry juices. Additionally, the isolated meningococcal pili bound to polyphenolic fractions of berry juices. The present study investigated the antiadhesive effects of berry juice polyphenolics against living meningococcal bacteria in a human epithelial cell culture model. The ability of bilberry, cranberry, crowberry and lingonberry juice polyphenolic fractions to inhibit the attachment of N. meningitidis bacteria to HEC‐1B human epithelial cells in a cell culture model was examined. The antibacterial effect of the fractions was tested using a microtiter broth microdilution assay. The most effective adhesion inhibition of 75% was achieved with cranberry juice polyphenolic fraction followed by crowberry (63%), bilberry (63%) and lingonberry (57%) juice polyphenolic fractions. Bacterial survival rates after incubation with the fractions varied between 75–100%. The present results suggest berry juice polyphenols as inhibitors of adherence of N. meningitidis. Thus the binding of meningococci to berry juice polyphenols might be protective for the host against the infection. Copyright © 2010 John Wiley & Sons, Ltd.

Antimicrobial activity of different Finnish monofloral honeys against human pathogenic bacteria

“…The controls were made each time for the studied strain in question and carried in the experiment at the same time with the sample. Different concentrations of the honey samples (80 μL) were then mixed with the diluted bacteria (20 μL) and the bacteria-honey mixtures were incubated in microtiter plates (Falcon Flexible Plate; Becton Dickinson Labware) at 37 °C for 2 h. The controls were prepared without adding honey to the reaction mixture or by adding ampicillin as described before 24–26. Shortly: a quantity of 80 μL of 0.05% THY or BHI broth with yeast extract in PBS was mixed with the diluted bacterial suspension of 20 μL (bacteria-broth/PBS control) and incubated in microtiter plate wells as described for the bacteria-honey samples.…”

Molecular Mechanisms That Define Redox Balance Function in Pathogen-Host Interactions—Is There a Role for Dietary Bioactive Polyphenols?

“…Polyphenolic compounds, some derived from dietary sources, have been shown to protect against intestinal barrier tight junction proteins exposed to oxidative stress [83] and also inhibit adhesion of some types of pathogenic bacteria to host cells [84][85][86] as well as to display anti-adherence effects on specific bacteria types [87,88]. For example, cranberry extracts have an affinity to inhibit the adherence of H. pylori in the gastrointestinal tract [89] and Streptococcus mutans in the oral cavity [90].…”

“…The polyphenolic fractions extracted and subsequently concentrated from bilberry, cranberry, crowberry, and lingonberry juice have exhibited anti-adhesive properties that function against Neisseria meningitidis and HEC-1B human epithelial cells [86]. The N. meningitidis actually binds to polyphenolic fractions of berry juices, thus protecting the host against infection [86]. Some specific examples of polyphenols derived from cranberries have been shown to reduce the adhesion of E. coli [85] and S. mutans [84].…”

Innovative Solutions to Sticky Situations: Antiadhesive Strategies for Treating Bacterial Infections

“…Although some studies of elderly and young women suggested that regular intake of cranberry juice results in a significant reduction in bacteriuria, additional studies have not shown a significant difference (220)(221)(222). However, high-molecular-weight polyphenols extracted and purified from cranberry extracts have demonstrated the ability to inhibit bacterial binding of E. coli (223), N. meningitidis (224), and S. mutans (225) to host tissue in vitro. While the mechanism of inhibition in many of these cases has not yet been fully elucidated, in the case of UTIs it is possible that the high level of fructose present in most cranberry juices may bind to the FimH adhesin in type 1 pili and compete with the natural mannosylated receptors.…”