Propolis polyphenolic compounds affect the viability and structure of Helicobacter pylori in vitro

Abstract To evaluate the anti- Helicobacter pylori activity of the major polyphenol compounds of propolis and their cellular damage, both as single molecule or in combination. Honey bees propolis were fractionated by using CPC and preparative HPLC. Four major polyphenols (chrysin, pinocembrin, galangin and caffeic acid phenethyl ester) were identified by thin layer chromatography–mass spectroscopy and liquid chromatography–mass spectroscopy. These compounds inhibited both ATCC and clinical H. pylori strains, with caffeic acid phenethyl ester being the most active. The four compounds presented minimum inhibitory concentration in the range 256–1024 μg ml −1 and a fractional inhibitory concentration of 64–512 μg ml −1 . In mixtures all compounds showed an indifference effect (FIC  H. pylori activity both as individual compounds and in mixture. When combined they present mainly indifference but exert a lytic activity upon H. pylori , suggesting a potential bactericidal activity of propolis.