Selected South African honeys and their extracts possess in vitro anti-Helicobacter pylori activity

Abstract

Background and aims: Eradication of Helicobacter pylori by triple therapy often results in a failure rate of 10-20%; thus, there is a need to seek alternative treatments. The aim of this study was to screen selected South African honeys for their anti-H. pylori activity, to extract the antimicrobial components using organic solvents and to determine the minimum inhibitory concentrations (MICs) of the extracts.

Methods: Three locally produced honeys from different regions in South Africa were screened for anti-H. pylori activity at four different concentrations using the agar well diffusion technique. Subsequently, Pure honey was extracted using n-hexane, diethyl ether, chloroform and ethyl acetate; extracts were also examined for anti-H. pylori activity by agar well diffusion method. The MICs of the three most active extracts were determined both by visual inspection and spectrophotometric analysis at 620 nm using the broth microdilution method. The results were analyzed by one-way ANOVA at 95% significance level.

Results: All honeys demonstrated anti-H. pylori activity and were most active at 75% v/v. The positive control (clarithromycin) recorded a zone diameter of 18.0 ± 7.4 mm not significantly different (p >0.05) from honeys at 75% v/v and solvent extracts. Chloroform extract recorded the lowest MIC(95) values that ranged from 0.156-5% v/v confirming this extract to be the most active.

Conclusion: All honeys demonstrated anti-H. pylori activity at concentrations ≥10%, as did the solvent extracts. Therefore, these honeys and solvent extracts possess potential compounds with therapeutic activity that could be further exploited as lead molecules in the treatment of H. pylori infections.