Honey is known to possess multifactorial antibacterial action. Its bactericidal potential against biofilm-embedded bacteria is limited though.

A recent study explored the impact of vitamin C on the antibacterial activity of natural honey against planktonic as well as biofilm-embedded bacterial pathogens. The antibacterial activity of four honey samples supplemented with vitamin C was expressed as the minimum inhibitory concentration (MIC).

At sub-MICs, vitamin C was shown to significantly increase the antibacterial activity of the tested samples against Pseudomonas aeruginosa in planktonic cultures. Following supplementation, honeydew honey, the most active form of honey, was found to be ineffective against Staphylococcus aureus. Contrary to that, supplementing 100% honeydew honey with vitamin C (100 mg/g of honey) in a multispecies wound biofilm model led to complete eradication of almost all bacterial isolates, including S. aureus. A combination of honey and vitamin C was partially effective against Enterococcus faecalis, while alone, honey had no action against this bacterium. Vitamin C counteracted hydrogen peroxide in honey solution and led to the elimination of the major antibacterial compound present in honey.

A combination of honey with vitamin C possibly incites the intracellular production of reactive oxygen species in bacterial cells; however, the exact cellular mechanisms remain to be elucidated.

Source: Majtan J, Sojka M, Palenikova H, et al. Vitamin C Enhances the Antibacterial Activity of Honey against Planktonic and Biofilm-Embedded Bacteria. Molecules. 2020 Feb 23;25(4). Pii: E992.