Anti-inflammatory activity of different species of thistles from Sardinia in gastric epithelial cells

Gastritis is an inflammatory disease involving millions of people in the world. It is caused, for the 90% of cases, by the presence of Helicobacter pylori (H. pylori). During H. pylori infection, gastric epithelial cells release high levels of IL-8, a typical NF-κB regulated gene strictly involved in gastric inflammation. Thistles species belong to the Asteraceae family. They are widely distributed in the Mediterranean area and they are traditionally used by Sardinian inhabitants for both alimentary and therapeutic purposes. The aim of this study is to compare the anti-inflammatory activity of eight wild edible thistles species from Sardinia, by an in vitro model of gastric inflammation. Among the selected thistles hydroalcoholic extracts, only those belonging to the Onopordum genus (Onopordum horridum Viv. and Onopordum illyricum L.) are able to reduce the IL-8 release in a concentration-dependent manner (IC50 4.31 g/mL and 12.3 g/mL, respectively). The effect observed is due, at elast in part, to the NF-κB pathway impairment. The phytochemical investigation of the two extracts reveals that the most abundant compounds contained in both thistle extracts, are 1,5 dicaffeoylquinic and 3,5 dicaffeoylquinic acids. These results suggest the ability of Onopordum species to exert a beneficial effect against gastric inflammatory diseases