Osmotic Effect of Honey on Growth and Viability of Helicobacterpylori

Honey from New Zealand and Saudi Arabia atconcentrations approximating 20% (v/v) inhibit thegrowth of H. pylori in vitro. The anti-H. pylori effectinvolves both hydrogen peroxide- andnon-peroxide-mediated killing mechanisms. This study was designed todetermine whether the anti-H. pylori activity of honeydiffered regionally (honey from Texas, Iowa, and NewZealand) and to determine whether this activity was due to the presence of hydrogen peroxide.Broth dilution susceptibility tests were performed usingsolutions of honey prepared in BHI broth ranging inconcentration from 5 to 35% (v/v) in 5% increments. Control solutions containing glucose, fructose,and combined glucose/fructose solutions in ratios of1:1.23 were also prepared. Paired catalase controls wereincluded in all tests. Twenty-eight clinical isolates of H. pylori were tested. Growth wasdetermined on the basis of a plus/minus grading score.All of the solutions containing either fructose,glucose, glucose and fructose combinations, or honey were equally effective in inhibiting the growthof H. pylori. All of the isolates were inhibited bysolutions containing 15% (w/v) carbohydrate. Honeysolutions, with or without catalase, inhibited 24/28 isolates at a concentration of 10%, and 28/28isolates at a concentration of 15%. In conclusion,regional differences in honey activity against H. pyloriwere not detected, nor was the effect of killing related to the presence of hydrogen peroxide inthe honey samples. Osmotic effects were shown to be themost important parameter for killing H. pylori as allcarbohydrate solutions 15% (v/v) inhibited 100% of the H. pylori.