Phytochemicals-mediated production of hydrogen peroxide is crucial for high antibacterial activity of honeydew honey.

Honeydew honey is increasingly valued due to its pronounced antibacterial potential; however, the underlying mechanism and compounds responsible for the strong antibacterial activity of honeydew honey are still unknown. The aim of this study was to investigate the inhibition of bacterial growth of 23 honeydew honey samples. Activity of bee-derived glucose oxidase (GOX) enzyme, the content of defensin-1 (Def-1) and hydrogen peroxide (HO), and total polyphenol content were determined in the 23 honey samples. Our results demonstrated that antibacterial activity of honeydew honey was equivalent to medical-grade manuka and kanuka honey and was abolished by catalase. Although HO is an important factor in the inhibition of bacterial growth, polyphenolic compounds and their interaction with HO are the key factors responsible for high antibacterial activity of honeydew honey. In addition, our results indicated that the antibacterial activity of honeydew honey is not dependent on GOX-mediated production of HO or the presence of Def-1.