Antimicrobial Properties of Honey
Citation
(2016) Antimicrobial Properties of Honey, no. 43.
Abstract
Background: Many countries and cultures worldwide use honey as a medicinal
remedy to treat a variety of burns and wound infections. Over the years, research
has provided evidence of the increasing antimicrobial properties exerted from
specific honeys. A number of factors such as pH, colour, polyphenol and antioxidant
levels, % sugar content and H2O2 content are all believed to contribute to these
antimicrobial properties, as well as the floral and geographical origins of the honey.
As such, the most widely researched honey, Manuka honey, has been highlighted as
a prime example of a honey that exerts powerful antimicrobial properties in inhibiting
the growth of infectious bacteria.
Aims and Objectives: In the present study, the aim was to investigate he
antimicrobial properties of a selection of honeys against wound infecting bacteria
Staphylococcus aureus. The biochemical composition would also be investigated
alongside the antibacterial properties of honey in combination with antibiotics.
Finally, the antibacterial properties of a recently discovered diacid isolate from honey
would also be explored.
Methods: The antimicrobial properties of the honeys were investigated after 24 and
48 hours incubation through the use of a serial broth dilution assay. Viable counts
were then made. The compositional analysis of honey was carried out using the
appropriate measures - pH strips for pH, Ciocalteau and Folin method for polyphenol
content, FRAP assay for antioxidant capacity and Refractometer for sugar content.
A qualitative analysis was carried out for the levels of H2O2 produced.
Results: Initial screening identified Chestnut and Kashmir honey as the most
antimicrobial out of the six samples tested. Manuka honey remained in the study as
a positive control. Significant reduction in bacteria growth was observed with the
three honeys after both 24 and 48 hours incubation (P<0.0001) compared to a TSB
growth control. Chestnut honey was identified as the strongest honey out of the
three and it was included in further investigation compared to a negative sugar
control. After 24 hours and 48 hours incubation, Chestnut honey caused significant
decrease in bacteria growth compared to the sugar control (P<0.05).
Conclusion: Many factors contribute to the antimicrobial properties of honey and the
importance of all factors has been indicated throughout this study. A synergistic
relationship is suggested between honey and antibiotics and the inhibitory action of
the diacid isolate is also apparent. Further investigation can be carried out on
different honeys against different strains of bacteria. The opportunity for further
investigation into the action of antibiotics with honey and the action of the diacid
isolate is also open.
Keywords: Honey, bacteria, antioxidants, polyphenols, antimicrobial, growth
inhibition.