In vitro inhibition of Helicobacter pylori growth and adherence to gastric mucosal cells by Pyenogenol®

The emergence of antibiotic resistant H. pylori strains has necessitated the identification of alternative additive therapies for the treatment of this infection. The study tested whether a specific pine bark extract (Pyenogenol (R)) is effective in inhibiting the growth and adherence of H. pylori in vitro. Inhibition of H. pylori growth by Pycnogenol (R) was tested in liquid medium as well as in an in vitro model by using sessile bacteria attached to AGS cells. Adherence was determined by co-incubation of gastric cells with Pycnogenol (R) and H. pylori in vitro. Pycnogenol (R) inhibited H. pylori growth in suspension with an MIC50 of 12.5 mu g/mL. Growth of H. pylori in infected cells was reduced to 10% of the control value by 125 mu g/mL Pycnogenol (R). Adherence of H. pylori to gastric cells was reduced by 70% after 3 h incubation with 125 mu g/mL Pycnogenol (R). The results show a significant, yet limited inhibition of growth and adherence of H. pylori to gastric cells by Pycnogenol (R). In vivo studies have to demonstrate the clinical relevance of these findings. Copyright (C) 2008 John Wiley & Sons, Ltd.