Antibacterial and Antioxidant Potency of Floral Honeys from Different Botanical and Geographical Origins

Hasan A Alzahrani,Balkees A Bakhotmah,Yuva Bellik,Laïd Boukraâ,Fatiha Abdellah,Rashid Alsabehi

doi:10.3390/molecules170910540

Hasan A Alzahrani, Balkees A Bakhotmah + Show 4 more

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https://doi.org/10.3390/molecules170910540

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Abstract

In order to assess their physicochemical and antioxidant properties as well as their antimicrobial potency, four varieties of honey from different botanical and geographical origins were used. The agar incorporation method was used to determine the antimicrobial potency of honeys. The total phenol content was determined by a modified Folin–Ciocalteu method and the free radical scavenging activity by the Fe3+ reducing power (FRAP) assay. Manuka honey was the most effective against Staphylococcus aureus Oxa R and S. aureus Oxa S with a Minimum Inhibitory Concentration (MIC) of 6% and 7%, respectively, whereas wild carrot honey was the most effective against Pseudomonas aeruginosa, with a MIC of 12%. Lavender honey was the least effective against all tested strains, even though was found to have the lowest pH and water content. Manuka honey had the highest content of polyphenols, with 899.09 ± 11.75 mg gallic acid/kg, whereas lavender honey had the lowest, with 111.42 ± 3.54 mg gallic acid/kg. A very significant correlation (r value was 0.9079 at P < 0.05) was observed between the total polyphenolic content and the Fe2+ content formed in the presence of the honey antioxidants. The differences between honey samples in terms of antibacterial and antioxidant activity could be attributed to the natural variations in floral sources of nectar and the different locations.

Highlights

It has been demonstrated in many studies that honey has antibacterial effects, attributed to its high osmolarity, low pH, hydrogen peroxide content, and content of other, uncharacterized compounds [1,2].The low water activity of honey is inhibitory to the growth of the majority of bacteria, but this is not the only explanation for its antimicrobial activity
Manuka honey had the lowest values of diastase number and proline and the highest HMF one
Correlations were established using Pearson’s correlation coefficient (r) in bivariate linear correlations (P < 0.01). These correlations were calculated using Microsoft office Excel 2007 and SPSS version 18.0 [54]. As it has been demonstrated in many studies, honey has a potent activity against bacteria and fungi

Summary

Introduction

It has been demonstrated in many studies that honey has antibacterial effects, attributed to its high osmolarity, low pH, hydrogen peroxide content, and content of other, uncharacterized compounds [1,2].The low water activity of honey is inhibitory to the growth of the majority of bacteria, but this is not the only explanation for its antimicrobial activity. It has been demonstrated in many studies that honey has antibacterial effects, attributed to its high osmolarity, low pH, hydrogen peroxide content, and content of other, uncharacterized compounds [1,2]. Hydrogen peroxide was identified as the major source of antibacterial activity in honey [4]. It is produced by the action of glucose oxidase on glucose, producing gluconic acid. This is inhibited by excessive heat and low water activity [4]. Manuka honey from New Zealand with nonperoxidal antibacterial activity has been found to be effective at a low concentration [7]. The antifungal activity of honey against Candida albicans has been reported in many studies [12,13,14]

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