Mānuka honey (Leptospermum scoparium) exerts a strong antibacterial effect. Bacterial enzymes are an important target for antibacterial compounds. The enzyme urease produces ammonia and enables bacteria to adapt to an acidic environment. A new enzymatic assay, based on photometric detection of ammonia with ninhydrin, was developed to study urease activity. Methylglyoxal (MGO) and its precursor dihydroxyacetone (DHA), which are naturally present in mānuka honey, were identified as jack bean urease inhibitors with IC50 values of 2.8 and 5.0mM, respectively. Urease inhibition of mānuka honey correlates with its MGO and DHA content. Non-mānuka honeys, which lack MGO and DHA, showed significantly less urease inhibition. MGO depletion from mānuka honey with glyoxalase reduced urease inhibition. Therefore, urease inhibition by mānuka honey is mainly due to MGO and DHA. The results obtained with jack bean urease as a model urease, may contribute to the understanding of bacterial inhibition by manuka honey.

Rückriemen J, Klemm O, Henle T. (2017)

Please follow the link for more info: https://pubmed.ncbi.nlm.nih.gov/28407946/