In vitro Assessment of Helicobacter pylori Ureases Inhibition by Honey Fractions

Abstract

Pathogenic effects associated with Helicobacter pylori infection include peptic ulcer. Pathogenicity is mediated by the bacteria ureases. The emerging resistance of H. pylori to clarithromycin used in combination with amoxicillin in the treatment of H. pylori infection has necessitated the search for other means of combating the scourge of H. pylori, hence the search for potent H. pylori urease inhibitor. The aim of the study was to evaluate honey fractions obtained from different geographic zones for H. pylori urease inhibitory potentials. Chloroform and diethyl-ether were used to extract honey fractions (HS) and Manuka honey (HM). H. pylori ureases were obtained from a 48-h culture through sonication. Urease activity was measured spectrophotometrically by assaying the reduction in NADH in coupled urease-glutamate dehydrogenase (GDH) system, whereas urease inhibition was calculated by comparing the NADH oxidation rate before and after incubation with honey fractions. Urease inhibition by the HS and HM were time and concentration independent. Chloroform extract of HS showed 48 and 42% inhibitory activities against urease from H. pylori (369C) and H. pylori (ATCC 43526), respectively, wheeras diethyl ether extract of HM showed 45 and 51% inhibitory activities against urease from H. pylori (369C) and H. pylori (ATCC 43526), respectively. Dixon plot revealed that HM extract showed mixed inhibition pattern in a reversible inhibition kinetics. Honey fractions were good inhibitors of H. pylori urease and may serve as a template in the development of urease inhibitors in pharmaceuticals.