In Vitro anti- Helicobacter pylori and urease inhibitory effects of polyphenolic extracts of local herbs from Algeria

Abstract

Gastritis and peptic ulcers are considered as major health problems worldwide with more than 80% of chronic active gastritis are due to the pathogenic bacterium H. pylori. Due to the emergence of antibiotic resistance among clinical strains of H. pylori, alternative approaches are increasingly needed. Methanolic extracts of Algerian originated Mentha rotundifolia, Eucalyptus globulus, Malva sylvestris, Inula viscosa, Achillea odorata and Utrica dioica and their contents of phenolics and flavonoids were evaluated for the in vitro antimicrobial activity against H. pylori in addition to its associated urease. The antimicrobial activity and determination of the MICs of these extracts against control strain of H. pylori was performed using standard agar diffusion method.  The highest phenolic and flavonoid contents were found in M. rotundifolia and E. globulus while M. sylvestris showed the least phenolic contents. In addition, polyphenolic fractions exhibited anti-H. pylori activity of all of the herbal extracts with  highest activity for E. globulus (MIC 0.094 mg/ml), I. viscosa, (0.375 mg/ml) and U. dioica (0.75 mg/ml), low antimicrobial activity was revield for  A. odorata, M. rotundifolia and Malva sylvestris respectively (MIC > 1 mg/ml).  For the urease activity, all extracts showed inhibitory effect at concentration of 250 mg/ml. However, the range of the urease inhibitory concentrations varied significantly among the extracts with highest activity and widest range found for E. globulus (70-90% at concentrations 8-125 mg/ml). In conclusion, the presence of potential antimicrobial activities in the polyphenolic extracts of medicinal plants against H. pylori and its associated urease would open the door for investigation of novel agents for the control of H. pylori infections