Study of antibacterial activity of selected Iranian plant extracts on Helicobacter pylori

Abstract

Helicobacter pylori is a major contributor to chronic gastritis, peptic, duodenal ulcers, and is associated with distal adenocarcinoma. Increasing resistance of H. pylori to common antibiotics is becoming an issue and finding new treatments are crucial. Aqueous and ethanolic extracts of Glycyrrhiza glabra, Filipendula ulmaria, Argentina anserine, Crataegus douglasii, Rubus fruticosus were tested, by agar diffusion and agar dilution method, against H. pylori clinical isolates. Among the aqueous extracts studied, G. glabra extract had the highest antibacterial effect on H. pylori (mean diameter of inhibition zone 14.7 mm) followed by Filipendula ulmaria, Rubus fruticosus, Argentina anserine, and Crataegus douglasii. Among the ethanolic extracts, Glycyrrhiza glabra extract was the most effective one (mean diameter of inhibition zone 9.9 mm), followed by Filipendula ulmaria, Argentina anserine, Rubus fruticosus, and Crataegus douglasii. Given the high levels of antibacterial activities of aqueous and ethanolic extracts of Glycyrrhiza glabra and Filipendula ulmaria, the next step is to identify the antimicrobial constituents of these plants.