title: Inhibitory and bactericidal activity of selected South African honeys and their solvent extracts against clinical isolates of Helicobacter pylori.
abstract: The growing problem of antibiotic resistance by Helicobacter pylori demands the search for novel compounds, especially from natural sources. We evaluated the anti-H. pylori activity of six local honeys at different concentrations as well as their solvent extracts by the Hole Plate diffusion method. The minimum inhibitory concentration (MIC50) of the two most active extracts of each honey was determined by the broth microdilution method; and the time kill assay of the most active extract of each honey determined by viability studies. Data were analyzed by one-way ANOVA test at 95% significance level. All the honey varieties as well as their solvent extracts demonstrated varying levels of antibacterial activity based on different mean zone diameters [16.0mm (crude) to 22.2mm (extract)] and percentage susceptibilities [73.3% (crude) to 93.3% (extract)] of the test isolates. The chloroform extracts of Pure Honey (PH) and Champagne Royal Train (CRT) recorded MIC50 ranges of 0.01-10% and 0.625-10 % (v/v) respectively; that were not significantly different (P > 0.05) from amoxicillin (0.001-1.25mg/mL), the positive control. The most potent bactericidal effect against the test isolates was obtained with 5% v/v (1/2 MIC) concentration of chloroform extract of PH from 42-72 hrs. In conclusion, these honeys and their extracts could be leads for further investigation in the discovery of new natural anti-H. pylori compounds.
authors.affiliation: Microbial Pathogenicity and Molecular Epidemiology Research Group, Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, P/Bag X1314, Alice, South Africa.
authors.forename: Christy Echakachi
authors.initials: CE
authors.lastname: Manyi-Loh
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Clarke
authors.forename: Ezekiel
authors.initials: E
authors.lastname: Green
authors.forename: Roland Ndip
authors.initials: RN
authors.lastname: Ndip
mesh_terms: D000085:Acetates / Q000737:chemistry; D000658:Amoxicillin / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001516:Bees; D002725:Chloroform / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004986:Ether / Q000737:chemistry; D016480:Helicobacter pylori / Q000187:drug effects* / Q000254:growth & development; D006586:Hexanes / Q000737:chemistry; D006722:Honey / Q000032:analysis*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D012997:Solvents / Q000737:chemistry*; D013019:South Africa
chemical_list: D000085:Acetates; D000900:Anti-Bacterial Agents; D006586:Hexanes; D012997:Solvents; D004986:Ether; C026385:n-hexane; C007650:ethyl acetate; D002725:Chloroform; D000658:Amoxicillin