Antibacterial Activity Of Honey Research Articles

Chemical characterisation, thermal analysis, and antibacterial activity of honeys from Caatinga stingless bees of Melipona spp.

In the present study, chemical characterisation, thermal analysis and antibacterial activity of honeys from Melipona spp. with occurrence in Caatinga biome of Brazil. The honeys presented pH from 4.07 to 4.14, density of 1.41 g/cm3 and °Brix value of 79.90. The thermogravimetry (TG) analysis presented six-seven events and differential thermal analysis (DTA) presented three-four endothermic peaks. HPLC fingerprint revealed a predominant presence of gallic acid and vanillin. Antioxidant activity evaluated using in vitro 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging with IC50 values in the range of 14.5404 to 15.2454 mg/mL. The honeys also showed antimicrobial activities against Staphylococcus aureus and Pseudomonas aeruginosa using a modified agar diffusion and microdilution method. The results of the present study demonstrate that the honey from stingless bees by Caatinga biome indicate polyphenol compounds, antioxidant activity and in vitro antimicrobial potential. The analytical methos permitted of fingerprint of samples.

Influence of different heat treatment regimes on the change of chemical composition and antibacterial activity of bee honey

The studies of the chemical composition and antibacterial activity of heather honey (Calluna vulgaris) subjected to heat treatment at 35–40°C for 12 hours were carried out. The temperature range (38–40°C), at which decrease in the H2O2 concentration, decrease in D-glucose-1-oxidase activity and increase in the 5-hydroxymethylfurfural content, was identified. The degree of chemical changes was directly proportional to the temperature and time of thermal exposure. The correlation between changes in the chemical composition and antibacterial activity of honey against test microorganisms Escherichia coli (strain 1257), Staphylococcus aureus (strain 209-P) and Bacillus cereus (strain 96) was established. The obtained results showed that heating honey to 37 °C even for 12 hours didn’t cause undesirable changes in its chemical composition and decrease in antibacterial activity. Thus, this temperature regime can be considered more gentle and recommended for use in the heat treatment of this food product.

Evaluation of the generation of reactive oxygen species and antibacterial activity of honey as a function of its phenolic and mineral composition.

The antibacterial activity (ABA) of honey is associated with the generation of reactive oxygen species (ROS), where polyphenols (PFs) play a key role due to their pro-oxidant action modulated by metallic cations. In this work, the contents of PFs, H2O2, OH radicals, Cu, Fe, Mn, Zn, and ABA against Staphylococcus epidermidis and Pseudomonas aeruginosa were determined in honeys from central Chile. Then, their relationships were evaluated through partial least squares regression. The average contents of phenolic acids, flavonoids and metals in honey ranged from 0.4 to 4μg/g, 0.3-1.5μg/g and 3-6μg/g, respectively. All honeys showed accumulation of H2O2 (1-35μg/g) and OH radicals. The PLS showed that gallic acid, p-coumaric acid, chrysin, kaempferol, Fe, and Mn stimulate the generation of ROS. Quercetin, Cu, and Zn showed marginal antioxidant effects. PFs favor the ABA of honey against both bacteria and H2O2 against S. epidermidis.

Evaluation of the medicinal potentials of honey against Pseudomonas aeruginosa isolated from various forms of wound infections

The rise of multidrug resistant microbial species is a major public health problem worldwide. Complementary natural sources with antimicrobial potentials including plants and plant-based products such as honey, are currently receiving great attention. As such, this study aimed to evaluate the medicinal potentials of honey by testing its antibacterial efficacy against Pseudomonas aeruginosa isolates associated with wounds infection. Clinical isolates of Pseudomonas aeruginosa from infected wounds such as sepsis, bite, surgical, laceration and gunshots were obtained from Federal Teaching Hospital Katsina. The antibacterial activity of honey was assayed by Agar well diffusion technique using different concentrations of honey; 25%, 50%, 75%, and 100% (v/v). Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of honey were also determined. The mean zone of inhibition of honey against the isolates range from 10.6 mm to 22.6 mm. Moreover, the inhibitory effects of honey at 100% (v/v) differ significantly compared to other concentrations. The Minimum Inhibitory Concentration of honey was determined to be 25% (v/v) while the Minimum Bactericidal Concentration was estimated to be 75% (v/v). Pseudomonas aeruginosa isolate from gunshot wound was more susceptible to honey and ciprofloxacin (control) compared to Pseudomonas aeruginosa from other wound types. This study's findings demonstrated honey's efficacy in treating wound infections. Natural products, such as honey, have enormous potential for combating antibiotic resistance. In vivo studies should be carried out to further study the impact of honey on biological systems.

Quantification of bioactive components and evaluation of microbial community and antibacterial activity from Heterotrigona itama and Tetrigona binghami honeys

SummaryStingless bee honey is a precious food product with therapeutic benefits. In this study, we determined the quality of Malaysian stingless bee honeys (Heterotrigona itama and Tetrigona binghami) by the physicochemical characteristics, phenolic compounds, and organic acids. Our results revealed that the major phenolic compounds in all honey samples were chlorogenic acid and myricetin, and the major organic acids contained gluconic acid and trans‐cinnamic acid. The microbial community in honeys characterised using 16S rRNA and ITS amplicon sequencing techniques showed that Lactobacillus was assumed to be the predominant bacterium in stingless bee honeys. Furthermore, the antibacterial activity of honeys was examined in order to further demonstrate their health benefits. Our results are intended to pave the road for stingless bee honeys' probiotic capacity to be extended into our daily life.

Antibacterial Activity of Imported Honey against Methicillin Resistant Staphylococcus aureus (MRSA) Isolated from Infected Wounds

The use of traditional and herbal medicine to treat infections has been in practice since the origin of mankind, and it was the only option for treatment before the era of antibiotics. This research work was aimed at evaluating the antibacterial activity of imported honey against methicillin resistant Staphylococcus aureus isolated from different wound infections.152Samples from different wounds were obtained from patients with infected wounds attending Murtala Muhammad Specialist Hospital and Muhammadu Abdullahi Wase Specialist Hospital, Kano. The isolates were identified and confirmed using biochemical tests. The antibacterial activity of the honey and minimum inhibitory concentration (MIC) against the isolates were determined using agar well diffusion and two-fold dilution method respectively. The results to detect MRSA revealed its incidence as 24.9%. The result of the antibacterial activity of honey revealed activity at all the concentrations with the diameter of zones of inhibition ranging from 8-34mm.The two imported honey used in the study showed varied bacteriostatic activities, and none of the isolates was resistant to the tested honeys. Therefore, the antibacterial activity of honey even at lower strength justify their efficacy in the treatment of wound infection.

Correlation of the antibacterial activity of commercial manuka and Leptospermum honeys from Australia and New Zealand with methylglyoxal content and other physicochemical characteristics.

Variation in the antibacterial potency of manuka honey has been reported in several published studies. However, many of these studies examine only a few honey samples, or test activity against only a few bacterial isolates. To address this deficit, a collection of 29 manuka/Leptospermum honeys was obtained, comprising commercial manuka honeys from Australia and New Zealand and several Western Australian Leptospermum honeys obtained directly from beekeepers. The antibacterial activity of honeys was quantified using several methods, including the broth microdilution method to determine minimum inhibitory concentrations (MICs) against four species of test bacteria, the phenol equivalence method, determination of antibacterial activity values from optical density, and time kill assays. Several physicochemical parameters or components were also quantified, including methylglyoxal (MGO), dihydroxyacetone (DHA), hydroxymethylfurfural (HMF) and total phenolics content as well as pH, colour and refractive index. Total antioxidant activity was also determined using the DPPH* (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing-antioxidant power) assays. Levels of MGO quantified in each honey were compared to the levels stated on the product labels, which revealed mostly minor differences. Antibacterial activity studies showed that MICs varied between different honey samples and between bacterial species. Correlation of the MGO content of honey with antibacterial activity showed differing relationships for each test organism, with Pseudomonas aeruginosa showing no relationship, Staphylococcus aureus showing a moderate relationship and both Enterococcus faecalis and Escherichia coli showing strong positive correlations. The association between MGO content and antibacterial activity was further investigated by adding known concentrations of MGO to a multifloral honey and quantifying activity, and by also conducting checkerboard assays. These investigations showed that interactions were largely additive in nature, and that synergistic interactions between MGO and the honey matrix did not occur.

Antibacterial Activity of Honey in Combination with Cinnamon

Emergence of antimicrobial resistance (AMR) is a major global concern today. High prevalence of multidrug resistant (MDR) bacteria cause the treatments to be less effective or ineffective and finally leads to higher rates of mortality. This situation urges the development of novel antimicrobial agents. Natural products have gained more attention as safe and cost-effective sources of candidate compounds. Honey possesses a potent antibacterial activity against a wide range of bacteria. High osmolarity, acidic pH, hydrogen peroxide production, and presence of nonperoxide compounds provide various mechanisms for honey to act against bacteria. Cinnamon also has the ability to act on a number of bacteria through destruction of cell membranes, anti-quorum sensing effect, ATPase inhibition and membrane porins inhibition. Thus, the combinations of honey and cinnamon have shown important interactions such as synergistic, additive and antagonistic effects due to the interactions among various constituents in them. Their combined action varies depending on the honey type, cinnamon plant species, cinnamon extract type, etc. Therefore, both honey and cinnamon can be considered as good candidates for developing new antimicrobial agents. Further studies are required to isolate and identify bioactive compounds and to clarify their exact mechanisms of action, antibacterial spectrum, and toxicities.

Comparison of antibacterial activities of some kinds of honey in Vietnam

Honey is a natural product with a variety of uses. The antibacterial activity of honey is one of the key factors that make honey beneficial. The study aims to compare some quality index and antibacterial capacity of some main kinds of honey in Vietnam (determined by the diameters of the inhibition zones, the minimum inhibitory concentration - MIC, and the bactericidal concentrations - MBC). The results showed that the honey samples met the quality requirements of TCVN 12605:2019  for honey, including free reducing sugar content (ranging 67 - 72 g/100 g), diastase activity (ranging from 5.58 ± 0.46 to 25.27 ± 0.05 Schad), HMF (5-Hydroxymethylfurfural) content (ranging from 18.06 ± 0.09 to 23.80 ± 0.25 mg/kg). All honey samples exhibited antibacterial activity against all eight strains of bacteria studied as follows: the diameters of the inhibition zones ranged from 8.50 ± 0.29 to 22.33 ± 1.53 (mm), MIC ranged from 0.15 ± 0.00 to 0.90 ± 0.14 (g/mL). Honey from coffee and rubber flowers showed strong bactericidal ability at MBC concentration from 0.25 g/mL.

Purification and identification of novel antibacterial peptides isolated from Tualang honey

SummaryThis study aimed to determine the role of bioactive peptides in the antibacterial activity of honey. The peptides were extracted, and the concentration was determined. The peptides were fractionated and evaluated for their antibacterial activity towards selected bacteria. The results showed high peptide content in Tualang honey 1.01 mg g−1. A total of seven essential amino acids were present in Tualang honey. The peptide mixture extracted from Tualang honey showed high antibacterial activity towards Staphylococcus aureus, Salmonella enterica serovar Typhimurium, Escherichia coli and Pseudomonas aeruginosa. A total of 33 peptides were identified in the fractions 9 and 10 obtained from RP‐HPLC. The identified peptides belonged to different sources including novel peptides that have no match to the protein database. The results of this first study revealed the role of the peptides generated by honeybees, nectar and pollen, and novel peptides of the natural microflora in the antibacterial activity of honey.

PROPUESTA DE UNA METODOLOGÍA PARA CUANTIFICAR LA ACTIVIDAD ANTIBACTERIANA DE LA MIEL

In this study a standardized method for objectively comparing the antibacterial activity of honey was developed. The assay was performed using a strain of S. aureus and four honeys that have been shown antibacterial activity against this strain. The antibacterial activity of honeys were checked by using an agar plate diffusion method using S. aureus (ATCC 29213) as the test organism. On the surface of each agar plate six stainless steel cylinders with a diameter of 8,14 mm were radially disposed. Onto each cylinder 0,1 mL of sample honey at 10% v/v was placed and all Petri dishes were incubated at 35°C during 24 h. Each sample were analyzed by triplicate. The surface of the cylinder diameter was set as reference antibacterial activity equivalent to minimal inhibitory concentration (MIC). The antibacterial activity of each honey was quantitated by the relationship between the surface of the inhibitory zone and the surface of the reference activity expressed as multiples of MIC (x MIC). The method allowed establishing differences between the bacterial activities of the different honeys tested and could be used for identifying honeys that could be employed with medicinal purpose for the treatments of wounds.

DILUCIÓN DE MIEL EN AGUA INDUCE HORMESIS EN LA ACTIVIDAD ANTIBACTERIANA SOBRE Staphylococcus aureus.

In pharmacology, hormesis is defined as the high efficacy of a drug at low doses and a decrease of efficacy at higher doses. In this study, the hormesis phenomenon on the antibacterial activity of honey was assessed. The activity of four honeys (A, D, C and D) were checked by agar plate diffusion method using S. aureus (ATCC 29213) as the test organism. Each honey was tested as follows; on the surface of an agar plate, five stainless steel cylinders with a diameter of 8,14 mm were radially disposed. Onto each cylinder 0,1 mL of the sample honey diluted in water at 50 – 25 - 12,5 -6,25 and 3,125 % v/v were placed. Plates were incubated at 35°C during 24 h. The surface of the cylinder diameter was set as reference antibacterial activity (Ra). The antibacterial activity of each honey was quantitated by the relationship between the surface of the inhibitory zone (Iz) and the surface of the reference activity (Iz/Ra). An increase in the antibacterial activity was observed at a concentration of water greater than 50% in honeys B and C. This hormetic behavior could be considered as indicator of the quality of the antibacterial activity of these honeys.

Bee Venom, Honey, and Royal Jelly in the Treatment of Bacterial Infections of the Oral Cavity: A Review.

Oral diseases affect a very large number of people, and the applied pharmacological methods of treatment and/or prevention have serious side effects. Therefore, it is necessary to search for new, safer methods of treatment. Natural bee products, such as honey, royal jelly, and bee venom, can be a promising alternative in the treatment of oral cavity bacterial infections. Thus, we performed an extensive literature search to find and summarize all articles about the antibacterial activity of honey, royal jelly, and bee venom. Our analysis showed that these bee products have strong activity against the bacterial strains causing caries, periodontitis, gingivitis, pharyngitis, recurrent aphthous ulcers, supragingival, and subgingival plaque. An analysis of average MIC values showed that honey and royal jelly have the highest antimicrobial activity against Porphyromonas gingivalis and Fusobacterium nucleatum. In turn, bee venom has an antibacterial effect against Streptococcus mutans. Streptococcus sobrinus and Streptoccus pyogenes were the most resistant species to different types of honey, and royal jelly, respectively. Moreover, these products are safer in comparison to the chemical compounds used in the treatment of oral cavity bacterial infections. Since the antimicrobial activity of bee products depends on their chemical composition, more research is needed to standardize the composition of these compounds before they could be used in the treatment of oral cavity bacterial infections.

Effects of the Carbohydrate Sources Nectar, Sucrose and Invert Sugar on Antibacterial Activity of Honey and Bee-Processed Syrups.

Honey is a functional food with health-promoting properties. Some types of honey are used in wound care for the treatment of acute and chronic infected wounds. Increased interest in using honey as a functional food and as a base for wound care products causes limited availability of raw honey. Numerous studies suggest that the protein content of honey is mainly comprised of bee-derived proteins and peptides, with a pronounced antibacterial effect. Therefore, the aim of our study was to characterize for the first time the antibacterial activity of raw honeys and bee-processed syrups which were made by processing sucrose solution or invert sugar syrup in bee colonies under field conditions. Furthermore, we compared the contents of glucose oxidase (GOX) and the levels of hydrogen peroxide (H2O2) in honey samples and bee-processed syrups. These parameters were also compared between the processed sucrose solution and the processed invert sugar syrup. Our results clearly show that natural honey samples possess significantly higher antibacterial activity compared to bee-processed syrups. However, no differences in GOX contents and accumulated levels of H2O2 were found between honeys and bee-processed syrups. Comparison of the same parameters between bee-processed feeds based on the two artificial carbohydrate sources revealed no differences in all measured parameters, except for the content of GOX. The amount of GOX was significantly higher in bee-processed sucrose solutions, suggesting that processor bees can secrete a higher portion of carbohydrate metabolism enzymes. Determination of honey color intensity showed that in bee colonies, bee-processed syrups were partially mixed with natural honey. Further research is needed to identify the key botanical compounds in honey responsible for the increased antibacterial potential of honey.

Antibacterial activity of honeys and potential synergism of honeys with antibiotics and alkaloid extract of Sophora alopecuroides plant against antibiotic-resistant Escherichia coli mutant.

Objective(s):The increase in multidrug-resistant Escherichia coli strains with an overactivated AcrAB-TolC efflux pump has reduced the effectiveness of synthetic antibiotics, such as ciprofloxacin. The activity of this efflux pump can be reduced by using natural products. This study aimed to use a combination of ciprofloxacin, honey, and alkaloid extract of Sophora alopecuroides against an E. coli mutant with an overactivated AcrAB-TolC pump. Materials and Methods:First the physicochemical properties, total alkaloid content, antioxidant activity, and the minimum inhibitory concentration (MIC) of three local honey samples: Konar (lotus), Avishan (Thyme), and Gavan (Astragalus) were evaluated. Then, the MIC of different combinations of honey, ciprofloxacin, and plant alkaloid extract and expression of acrA and soxS genes were carried out using the agar dilution method and quantitative RT- PCR methods.Results:The net absorbance, total alkaloid content, and DPPH radical scavenging activity of Konar honey were significantly higher than those of Avishan and Gavan honeys (P<0.05). However, the MIC of lotus honey was nearly similar to other honey types, and all honey (30% w/v)-ciprofloxacin combinations decreased the viability of mutant more than ciprofloxacin alone. A synergistic interaction (FICI =0.48) was observed in triplex complex of ciprofloxacin (10 µg/ml), honey (20% w/v), and plant extract (1 mg/ml). A significant decrease (P<0.05) in the expression level of genes was seen in the presence of the triplex complex. Conclusion:It is concluded that the interaction between honey and plant alkaloid extract enhanced the anti-pump activity and reduced the oxidative stress response of the E. coli mutant.

Relationship between color and antibacterial activity of honey from Bahia, Brazil

Honey is a material of varied consistency and color, produced by bees from material collected in flowers, the nectar. It has a complex chemical composition, which depends on several factors, mainly of botanical and climatic origin, and a color scale for honey has been established. In this study, we evaluated the relationship between the color of 10 honey samples collected in the state of Bahia and their activity against three species of bacteria: Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The antibacterial potential was verified in all samples and a significant relationship between color and microbial activity against Staphylococcus aureus was obtained, reinforcing the hypothesis that darker honeys tend to have greater antibacterial potential.

Antibacterial properties of Tualang, Acacia and Yemeni Sumur honey against selected food spoilage bacteria and foodborne pathogens

The antibacterial activity of honey is mainly credited to its acidity, osmolarity and enzymatic generation of hydrogen peroxide via glucose oxidase. Additional honey components, such as aromatic acids or phenolic compounds, also contribute to the overall antibacterial activity. The level of antibacterial activities found in honey varies with different types of honey, due to mainly the composition, percentage as well as the nature of the sugars present in the honey. This study aimed to evaluate the antibacterial activity of four types of honey, namely Tualang honey (TH1), Tualang honey (TH2), Acacia honey (AH) and Yemeni Sumur honey (YSH). Nine bacterial strains were used. Disc diffusion, well diffusion, minimum inhibitory concentration (MIC), Minimum bactericidal concentration (MBC), and time-kill methods were performed to reveal the antibacterial potential of the selected honey. The MIC values ranged between 12.5 to 50% for both TH1 and YSH while for TH2, and AH it ranged between 25 to 50%. For MBC, it ranged from 25 to 50%. The time-kill in TH1 Staphylococcus aureus (food isolate) showed total inhibition at 6 hrs in 2 X MIC, and for Staphylococcus aureus ATCC 29737 was 3.84 log CFU/g at the 6 hrs. Physicochemical quality of honey resulted as follows: the pH of the honey samples was acidic in nature ranging between 3.69 to 3.94, and the aw of the honey samples were between 0.53 to 0.69. For colour analysis, YSH was observed to has the maximum lightness and yellowness, and TH1 has the maximum redness. While, AH had a minimum lightness, redness, and yellowness.

Colloidal structure of honey and its influence on antibacterial activity.

Honey colloidal structure emerges as a new trend in research on honey functions since it became recognized as a major factor altering bioactivity of honey compounds. In honey complex matrix, macromolecules self-associate to colloidal particles at the critical concentration, driven by honey viscosity. Sequestration of macromolecules into colloids changes their activities and affects honey antibacterial function. This review fills the 80-year-old gap in research on honey colloidal structure. It summarizes past and current status of the research on honey colloids and describes physicochemical properties and the mechanisms of colloid formation and their dissociation upon honey dilution. The experimental observations are explained in the context of theoretical background of colloidal science. The functional changes and bioactivity of honey macromolecules bound to colloidal particles are illustrated here by the production of H2 O2 by glucose oxidase and the effect they have on antibacterial activity of honey. The changes in the production of H2 O2 and antibacterial activity of honey were coordinated with the changes in the aggregation-dissociation states of honey colloidal particles upon dilution. In all cases, these changes were nonlinear, assuming an inverted U-shaped dose-response curve. At the curve maximum, the production of H2 O2 and antibacterial activity reached the peak. The curve maximum signaled the minimum honey concentration required for the phase separation. With phase transition from two-phase colloidal condense state to dilute state dispersion, the change to opposite effects of dilution on these honey's activities occurred. Thus, the colloidal structure strongly influences bioactivity of honey compounds and affects its antibacterial activity.

Relationship Among Antibiotic Residues And Antibacterial Activity Of The Endemic Spurge Honey (Euphorbia Resinifera O. Berg) From Morocco

Antibiotic-resistant bacteria continue to be of major health concern worldwide. In recent years, several reports and scientific articles claim the contamination of honey by antibiotics, detectable concentrations of antibiotic residues in honey are illegal. They, may cause hypersensitivity or resistance to drug therapy in humans, and are perceived by consumers as undesirable. In this sense, the purpose of this work was to examine the antibacterial activity of the Euphorbia resinifera (E. resinifera) honey against Escherichia coli and Staphylococcus aureus in vitro using the well-agar diffusion assay followed by dilution range to obtain more precise minimum inhibitory concentration values. The second aim is to evaluate the presence of antibiotics in honey using a screening test: Evidence InvestigatorTM, an immuno-enzymatic method for detection of 27 antibiotic residues followed by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) for confirmation of suspect samples; in order to assess the relationship between the presence of antibiotic residues and the antibacterial activity of honey. In this study, a total of 37 E. resinifera honey samples were analyzed. The results show that all samples of honey inhibited the growth of bacteria at the dilutions at 50% (v/v); the highest inhibition zone (25.98 ± 0.11 mm) was recorded from sample 5 for Staphylococcus aureus and (13.84 ± 1.10 mm) in sample 17 for Escherichia coli and that 50% (v/v) dilutions showed significant antibacterial effect compared to other dilutions (6.25, 12.5, 25% (v/v)). In all samples, there were no antibiotic residues detected except for one showing the detection of Trimethoprim at 6.48 µg kg-1. Our research is one of the first studies that relate the he relationship between the presence of antibiotic residues and the antibacterial activity of Euphorbia resinifera honey and showed that the antibacterial activity of honey might be due to the high osmotic nature, a low pH, its content of phenolic compounds and hydrogen peroxide and also to its content of methylglyoxal.

Demanding New Honey Qualitative Standard Based on Antibacterial Activity.

Honey is a functional food with health-beneficial properties and it is already used as a medical device in wound care management. Whether ingested orally or applied topically, honey must fulfill the requirements of international standards based on physicochemical characteristics. However, there is an urgent need for some additional standards reflecting biological properties. The aim of the study was to evaluate the antibacterial activity of 36 commercial honey samples purchased from supermarkets and local food shops and compare their efficacy to that of three honey samples from local beekeepers and three types of medical-grade honey. Furthermore, the hydrogen peroxide (H2O2) content and protein profile were assessed in all honey samples. Analysis of the antibacterial activity of commercial honeys revealed that 44% of tested samples exhibited low antibacterial activity, identical to the activity of artificial honey (sugars only). There was a significant correlation between the overall antibacterial activity and H2O2 content of honey samples. However, in some cases, honey samples exhibited high antibacterial activity while generating low levels of H2O2 and vice versa. Honey samples from local beekeepers showed superior antibacterial activity compared to medical-grade honeys. The antibacterial activity of honey can be easily altered by adulteration, thermal treatment or prolonged storage, and therefore it fulfils strict criteria to be suitable new additional quality standard.