Anti-Helicobacter pylori activity of aqueous extracts from Achyrocline species and Pseudognaphalium gaudichaudianum

Abstract

Flowering tops from several species of the Achyrocline and Pseudognaphalium genera, commonly named "marcelas", have various uses in Argentinean popular medicine, especially in gastrointestinal disorders (digestive, carminative, antispasmodic, anti-inflammatory and antiulcerogenic activities). Helicobacter pylori is associated with various diseases of the upper gastrointestinal tract, such as gastric inflammation and duodenal and gastric ulcers. In this work the anti-H. pylori activity of aqueous extracts from three species Achyrocline satureioides (Lam.) DC. (AS), A. venosa Rusby (AV), and Pseudognaphalium gaudichaudianum (DC.) Anderb. (PG) was investigated. The aqueous extracts were standardized by HPLC-DAD, and mostly two flavonoids: quercetin and 3-O-methylquercetin was determined. Anti-H. pylori activity was evaluated by broth microdilution method. The aqueous extracts showed inhibitory activity and synergistic effect with Cla, Mtz or Amx against strains of H. pylori. This is the first study to demonstrate that extracts of “marcelas” species possess anti-H. pylori activity. Therefore, species of the Achyrocline and Pseudognaphalium genera, could be used as new antibacterial drugs or in combination therapy against this microorganism.