Most commercially available therapeutic honey is derived from New Zealand, produced from the Leptospermum scoparium (manuka) plant, which exhibits broad-spectrum antimicrobial activity against a diverse range of bacterial and yeast pathogens.
Manuka honey is also equally effective against multi-drug resistant bacteria, said the UTS study. The activity of manuka honey is largely due to the presence of methylglyoxal (MGO), which is produced non-enzymatically from dihydroxyacetone (DHA) present in manuka nectar.
However, New Zealand may not be able to support the growing demand for medical-grade honey as its supply is at risk due to infection of their honey bee (Apis mellifera) populations by the parasitic varroa mite – associated with colony collapse disorder, an alarming phenomenon that significantly threatens global honey production.
Therefore, new research from the University of Technology Sydney (UTS) suggests Australia can help fulfill supply demands for medical-grade honey. The country has more than 80 Leptospermum species, and to date, the limited research has found at least some produce honey with high non-peroxide antibacterial activity (NPA) similar to New Zealand’s manuka.
The findings are described as a game-changer for Australian beekeepers, who stand to benefit from the lucrative medicinal honey market, and clinicians seeking treatments for resistant skin infections and chronic and acute wounds.
“Our study provides the proof for what we’ve long assumed – that this compound, methylglyoxal (MGO), is present in high levels in Australian manuka honeys. We’ve also shown that the activity of Australian manuka honeys has remained unchanged over seven years from harvest, which has huge implications for extending the shelf life of medicinal honey products,” said Dr Nural Cokcetin, of the ithree institute at UTS, the lead author of the study which also included collaborators at the University of Sydney and the University of the Sunshine Coast.
“What makes manuka honey so special is the exceptionally high level of stable antibacterial activity that arises from a naturally occurring compound in the nectar of manuka flowers. It’s the ingredient we know acts against golden staph and other superbugs resistant to current antibiotics.
“These findings put Australian manuka honey on the international radar at a time when antibiotic resistance is recognised as a global crisis.”
A team led by Professor Liz Harry at UTS studied more than 80 honey samples from NSW and Queensland flowering manuka (Leptospermum) trees and found the nectar-derived chemical that gives New Zealand manuka honey its unique antibacterial properties is present in some of the Australian varieties. The research also showed the antibacterial properties of honey remain unchanged over several years when stored appropriately.
Australia is home to 83 of the 87 known Leptospermum species and is still free of the varroa mite, unlike the rest of the beekeeping world.
Source: PLOS ONE
“The antibacterial activity of Australian Leptospermum honey correlates with Methylglyoxal levels.”
Authors: Nural N Cokcetin, et al.