Honey antibacterial activity: A neglected aspect of honey quality assurance as functional food

Background: Honey is considered as a functional food with health-promoting properties. Its potent antibacterial and antibiofilm effects are the major attributes of so called ‘medical-grade honey’ which is topically used for the treatment of burns, wounds and skin disorders. Nevertheless, the current set of honey quality parameters adopted in the European Union do not include its biological properties. Furthermore, in light of the accelerated growth of scientific evidence, there is an urgent need to revise current qualitative tools, and to establish and certify more effective honey quality control. Scope and approach: This up-to-date narrative review aims to discuss the recent clinical evidence describing the use of honey in the management of various disorders including respiratory tract infections, metabolic and gastro-intestinal derangements. Current knowledge about the antibacterial activity of honey, as the most studied biological properties of natural honey, focusing on mechanism of action and the factors/compounds responsible for the antibacterial effects is also discussed. In addition, the weaknesses of current honey quality parameters are highlighted and a new potentially qualitative parameter that takes into account honey functionality is presented. Key findings and conclusions: Data from in vitro and in vivo experiments, as well as human clinical studies clearly indicate the importance and efficacy of honey as an antibacterial agent. Antibacterial activity can vary from honey to honey but must not be identical to the activity of the honey sugar content. In most cases, antibacterial activity can be negatively impacted by thermal processing and long-term storage and this activity is therefore a suitable and sensitive quality parameter. From a clinical point of view, we strongly advocate to solely use natural honey that has undergone only minimal processing in order to preserve the full spectrum of biological activities. © 2021 Elsevier Lt

Physicochemical Characterization and Biological Properties of Pine Honey Produced across Greece

Pine honey is a honeydew honey produced in the East Mediterranean region (Greece and Turkey) from the secretions of the plant sucking insect Marchalina hellenica (Gennadius) (Coccoidea: Marchalini-dae) feeding on living parts of Pinus species. Nowadays, honeydew honey has attracted great attention due to its biological activities. The aim of this study was to study unifloral pine honey samples produced in Greece regarding their physicochemical parameters and antioxidant and antibacterial activity against five nosocomial and foodborne pathogens. These honeys showed physicochemical and microscopic characteristics within the legal limits, except for diastase activity, a parameter known to be highly variable, depending on various factors. Substantially higher levels of H2 O2 were estimated compared to other types of honeydew honey, whereas protein content was similar. The total phenolic content was 451.38 ± 120.38 mg GAE/kg and antiradical activity ranged from 42.43 to 79.33%, while FRAP values (1.87 to 9.43 mmol Fe+2 /kg) were in general higher than those reported in the literature. Various correlations could be identified among these parameters. This is the first attempt to investigate in depth the antibacterial activity of pine honey from Greece and correlate it with honey quality parameters. All tested honeys exerted variable but significant antibacterial activity, expressed as MIC and MBC values, comparable or even superior to manuka honey for some tested samples. Although honey antibacterial activity is mainly attributed to hydrogen peroxide and proteins in some cases (demonstrated by elevated MICs after catalase and Proteinase K treatment, respectively), no strong correlation between the antibacterial activity and hydrogen peroxide concentration or total protein content was demonstrated in this study. However, there was a statistically significant correlation of moisture, antioxidant and antibacterial activity against Klebsiella pneuomoniae, as well as antioxidant and antibacterial activity against Salmonella ser. Typhimurium. Interestingly, a statistically significant negative correlation has been observed between. © 2022 by the authors. Licensee MDPI, Basel, Switzerland