Helicobacter pylori: ancient human host but always new pathogen. Towards new therapeuticals approaches

Helicobacter pylori (H. pylori) is a microaerophilic spiral bacterium that has been associated with the pathogenesis of active and chronic gastritis, peptic ulcer, and gastric carcinoma. In 1994, H. pylori was classified as a type one carcinogen, and it appears to be responsible for 5.5% of all cancers worldwide. Antibiotic therapy has been successfully used against H. pylori but with increasing drug resistance, failure to eradicate the bacterium is more common. Although H. pylori is considered a non-invasive pathogen, an intracellular location of the bacterium both in vitro and in vivo has been widely reported. Therefore, new drugs should present activity against both the extracellular and intracellular microorganisms. Development of drugs from natural sources is receiving attention because of their potential to delay the onset of resistance and keep the pathogenic strains drug sensitive for longer time. Artemisinin extracted from Artemisia annua, has been used in traditional Chinese medicine for over two millennia. Different artemisinin derivatives have been developed. Artemisinin and its derivatives possess antimicrobial, antileishmanial, and antitumor activities. Our study showed that artemisinin derivatives were active against extracellular and the intracellular H. pylori suggesting consideration for treatment of H. pylori infection. Finally, several clinical extra-gastric diseases, have been reported. For some of these, the pathogenic mechanism is clear. Guidelines suggest that, after H. pylori infection determination, the eradication antibiotic therapy is recommended. Of 51 antibiotics in clinical development, less than 10% have chance to be used. So, new therapeutical approaches for the management of H. pylori infection are required.