The effect of dilution on the rate of hydrogen peroxide production in honey and its implications for wound healing

Characterization of Swarna Bhasma and Swarnaprash and Determination of Antimicrobial Properties Against Gut-Pathobiont and Symbiont

Ayurveda has a long-standing tradition of healthcare in Southeast Asia. Swarnaprash, a classical Ayurveda preparation, is commonly given as the pre-lacteal feed to neonates to prevent labor-related complications and infections. It comprises incinerated gold particles (InAuP/Swarna Bhasma), honey (Madhu), and clarified butter oil (CBO/Cow Ghrita). This in vitro study aimed to evaluate the therapeutic potential of the individual ingredients and combinations of Swarnaprash against selected neonatal gut pathobionts and symbionts. The study employed sophisticated instruments, including SEM with EDAX and X-ray diffraction analysis, to investigate the shape and structural disparities in the ingredients of Swarnaprash. The reported size of gold particles in Swarnaprash ranges from 0.6 to 9.5 µm. These particles are relatively smaller than those in Swarna Bhasma but larger than synthetic gold particles. Swarnaprash demonstrated both bactericidal and bacteriostatic activity against selected neonatal gut pathobionts, with the largest inhibition zones observed for P. aeruginosa and S. Typhi. It surpassed the individual efficacy of its components-Prash, InAuPs, honey, or CBO alone. Notably, Swarnaprash did not affect the selected beneficial gut bacteria. The results warrant further in vivo and clinical studies to explore the effects of Swarnaprash on neonatal gut flora, which would provide vital information for research in neonatal healthcare.

The effect of medical grade honey on tensile strength, strain, and Young's modulus of synthetic absorbable suture material used in equine surgery

BACKGROUND

Medical grade honey (MGH) has been introduced as a protective measure against surgical site infections in equine surgery, but the effect on suture material has not been investigated.

OBJECTIVE

To evaluate the effect of MGH on the tensile properties of three synthetic absorbable suture materials.

STUDY DESIGN

In vitro experiments.

METHODS

Ten strands of Polydioxanone USP 2 (PD2), Polyglactin 910 USP 2 (PG2) and Polyglecaprone USP 2-0 (PC2-0) were incubated 1, 7, 14, 21 and 28 days in MGH, phosphate-buffered saline (PBS), equine plasma (EP) and MGH mixed with equine plasma (HP). Mechanical testing was performed recording maximum load at failure (N), strain at failure and Young's modulus (N/mm2 ). The results were reported from a Welch or regular ANOVA.

RESULTS

PD2 in MGH had a significantly higher tensile strength compared to PD2 in EP (p < 0.05, mean difference (md) = 16.95 N, CI95% (9.19-24.70 N)) and PBS (p < 0.05, md = 14.48 N CI95% (6.73-22.23 N)) on day 7 and the remaining time points. PG2 incubated in MGH had a significantly higher tensile strength compared to EP (p < 0.05, md = 69.28 N CI95% (64.16-74.40 N)) and PBS (p < 0.05, md = 56.90 N CI95% (51.78-62.02 N)) until day 28. PC2-0 incubated in MGH had a significantly higher tensile strength compared to EP (p < 0.05 md = 12.40 N CI95% (4.59 N-20.20 N)) and PBS (p < 0.05 md = 11.23 CI95% (3.42-19.03 N)) on day 7 and the remaining time points.

MAIN LIMITATIONS

The sutures were unloaded during incubation and a single cycle to failure test was only performed, which does not reflect the in vivo environment where shear forces are present.

CONCLUSIONS

MGH did not negatively affect the tensile strength of the suture material and can safely be applied in contact with suture materials commonly used in equine surgery.

A preliminary metabarcoding analysis of Portuguese raw honeys

The microbial diversity in Portuguese raw honeys remains largely uncharacterized, constituting a serious knowledge gap in one of the country's most important resources. This work provides an initial investigation with amplicon metabarcoding analysis of two Lavandula spp. from different geographical regions of Portugal and one Eucalyptus spp. honey. The results obtained allowed to identify that each honey harbors diverse microbiomes with taxa that can potentially affect bee and human health, cause spoilage, and highlight bad bee-hive management practices. We verified that prokaryotes had a tendency towards a more marked core bacterial and a relative homogenous taxa distribution, and that the botanical origin of honey is likely to have a stronger impact on the fungal community. Thus, the results obtained in this work provide important information that can be helpful to improve this critical Portuguese product and industry.

Characterisation of physicochemical parameters and antibacterial properties of New Caledonian honeys

Honey is an attractive natural product with various health benefits. A few honey-based commercial products have successfully been adopted in clinics to improve wound healing. However, screening of other potential sources of medical-grade honey, in particular, honeys from territories with high floral species diversity and high endemicity, is highly needed. The goal of this study was to characterise the physicochemical and antibacterial properties of New Caledonian honey samples (n = 33) and to elucidate the major mechanism of their antibacterial action. Inhibitory antibacterial activity of honeys against Staphylococcus aureus and Pseudomonas aeruginosa was determined with a minimum inhibitory concentration (MIC) assay. Enzymatic activity of glucose oxidase and the content of hydrogen peroxide (H2O2) in honey samples were analysed. Furthermore, total protein content of honeys together with their electrophoretic protein profiles were also determined in the study. The antibacterial efficacy of 24% of the tested honey samples was slightly superior to that of manuka honey with unique manuka factor 15+. The antibacterial activity of catalase-treated honey sample solutions was significantly reduced, suggesting that H2O2 is a key antibacterial compound of diluted honeys. However, the kinetic profiles of H2O2 production in most potent honeys at a MIC value of 6% was not uniform. Under the experimental conditions, we found that a H2O2 concentration of 150 μM in diluted honeys is a critical concentration for inhibiting the growth of S. aureus. In contrast, 150 μM H2O2 in artificial honey solution was not able to inhibit bacterial growth, suggesting a role of phytochemicals in the antibacterial activity of natural honey. In addition, the continuous generation of H2O2 in diluted honey demonstrated an ability to counteract additional bacteria in re-inoculation experiments. In conclusion, the tested New Caledonian honey samples showed strong antibacterial activity, primarily based on H2O2 action, and therefore represent a suitable source for medical-grade honey.

Evaluating leishmanicidal effects of Lucilia sericata products in combination with Apis mellifera honey using an in vitro model

Leishmaniasis is a zoonotic disease caused by an intracellular parasite from the genus Leishmania. Lack of safe and effective drugs has increasingly promoted researches into new drugs of natural origin to cure the disease. The study, therefore, aimed to investigate the anti-leishmanial effects of Lucilia sericata larval excretion/secretion (ES) in combination with Apis mellifera honey as a synergist on Leishmania major using an in vitro model. Various concentrations of honey and larval ES fractions were tested against promastigotes and intracellular amastigotes of L. major using macrophage J774A.1 cell line. The inhibitory effects and cytotoxicity of ES plus honey were evaluated using direct counting method and MTT assay. To assess the effects of larval ES plus honey on the amastigote form, the rate of macrophage infection and the number of amastigotes per infected macrophage cell were estimated. The 50% inhibitory concentration (IC50) values were 21.66 μg/ml, 43.25 60 μg/ml, 52.58 μg/ml, and 70.38 μg/ml for crude ES plus honey, ES >10 kDa plus honey, ES <10 kDa plus honey, and honey alone, respectively. The IC50 for positive control (glucantime) was 27.03 μg/ml. There was a significant difference between viability percentages of promastigotes exposed to different doses of applied treatments compared to the negative control (p≤ 0.0001). Microscopic examination of amastigote forms revealed that dosages applied at 150 to 300 μg/ml significantly reduced the rate of macrophage infection and the number of amastigotes per infected macrophage cell. Different doses of larval products plus honey did not show a significant toxic effect agaist macrophage J774 cells. The larval ES fractions of L. sericata in combination with A. mellifera honey acted synergistically against L. major.

Performance of a Flow-Through Enzyme Reactor Prepared from a Silica Monolith and an α-Poly(D-Lysine)-Enzyme Conjugate

Horseradish peroxidase (HRP) is covalently bound in aqueous solution to polycationic α-poly(D-lysine) chains of ≈1000 repeating units length, PDL, via a bis-aryl hydrazone bond (BAH). Under the experimental conditions used, about 15 HRP molecules are bound along the PDL chain. The purified PDL-BAH-HRP conjugate is very stable when stored at micromolar HRP concentration in a pH 7.2 phosphate buffer solution at 4 °C. When a defined volume of such a conjugate solution of desired HRP concentration (i.e., HRP activity) is added to a macro- and mesoporous silica monolith with pore sizes of 20-30 µm as well as below 30 nm, quantitative and stable noncovalent conjugate immobilization is achieved. The HRP-containing monolith can be used as flow-through enzyme reactor for bioanalytical applications at neutral or slightly alkaline pH, as demonstrated for the determination of hydrogen peroxide in diluted honey. The conjugate can be detached from the monolith by simple enzyme reactor washing with an aqueous solution of pH 5.0, enabling reloading with fresh conjugate solution at pH 7.2. Compared to previously investigated polycationic dendronized polymer-enzyme conjugates with approximately the same average polymer chain length, the PDL-BAH-HRP conjugate appears to be equally suitable for HRP immobilization on silica surfaces.

Changes in antibacterial activity, colour, and hydrogen peroxide content of Western Australian Jarrah and Marri honeys after storage at different temperatures over time

AIMS

This study aimed to evaluate the effects of storage and different temperatures on the antibacterial activity and physicochemical characteristics of several types of honey.

METHODS AND RESULTS

Honeys stored for 16 weeks at 37 and 45°C showed significant declines in antibacterial activity determined by minimum inhibitory concentrations, the loss of hydrogen peroxide, decreases in honey pH, and increases in honey colour, with changes most pronounced at 45°C. In contrast, honeys stored for 16 weeks at ambient (∼22°C) and cold (4, -20, and -80°C) temperatures showed only minor changes. In a second set of 12 honeys stored for 16-32 months at ambient temperature and then 4°C, honeys showed minor changes in antibacterial activity, increases in colour, and decreases in pH. For a third set of 17 honeys stored for five years at ambient temperature, the honeys showed almost complete loss of hydrogen peroxide and were all significantly darker in colour, but showed varied changes in antibacterial activity.

CONCLUSIONS

Heat was detrimental to the antibacterial activity of honeys, as was long-term storage at ambient temperatures for some honeys but not others.

Exploring the Potential of Bee-Derived Antioxidants for Maintaining Oral Hygiene and Dental Health: A Comprehensive Review

Honey bee products comprise various compounds, including honey, propolis, royal jelly, bee pollen, bee wax and bee venom, which have long been recognized for their pharmacological and health-promoting benefits. Scientists have discovered that periodontal disorders stem from dental biofilm, an inflammatory response to bacterial overgrowth produced by dysbiosis in the oral microbiome. The bee products have been investigated for their role in prevention of oral diseases, which are attributed to a myriad of biologically active compounds including flavonoids (pinocembrin, catechin, caffeic acid phenethyl ester (CAPE) and galangin), phenolic acids (hydroxybenzoic acid, hydroxycinnamic acid, p-coumaric, ellagic, caffeic and ferulic acids) and terpenoids. This review aims to update the current understanding of role of selected bee products, namely, honey, propolis and royal jelly, in preventing oral diseases as well as their potential biological activities and mechanism of action in relation to oral health have been discussed. Furthermore, the safety of incorporation of bee products is also critically discussed. To summarize, bee products could potentially serve as a therapy option for people suffering from a variety of oral disorders.

Unexpected Value of Honey Color for Prediction of a Non-Enzymatic H2O2 Production and Honey Antibacterial Activity: A Perspective

Hydrogen peroxide is the principal antibacterial compound of honey and its concentration determines honey bacteriostatic (MIC) and bactericidal (MBC) potencies. Levels of H₂O₂ produced are highly relevant to honey therapeutic potential, but they vary extensively among honey with reasons not immediately apparent. According to a traditional view, H₂O₂ is produced as a by-product of glucose oxidation by the honey bee enzyme, glucose oxidase; however, significant levels of H₂O₂ could be produced in a non-enzymatic way via polyphenol autooxidation. The aim of this study was to evaluate the potential for such an alternative pathway by re-examining evidence from many experimental and correlative studies in order to identify factors and compounds required for pro-oxidant activity. Unexpectedly, the color intensity was found to be the main indicator separating honey varieties based on the quantitative differences in the polyphenolic content, antioxidant activity and the content of transition metals, Fe, Cu and Mn, the main factors required for pro-oxidant effects. The color-impeding polyphenolics and their oxidation products (semiquinones and quinones) further contributed to color development through multiple chemical conjugations with proteins, phenolic oxidative polymerization, chelation or the reduction of metal ions. Moreover, quinones, as an intrinsic part of polyphenol redox activity, play an active role in the formation of higher-order structures, melanoidins and colloids in honey. The latter structures are also known to chelate metal ions, potentially contributing to H₂O₂ production. Thus, the color intensity appears as a major parameter that integrates polyphenol-dependent pro-oxidant reactions resulting in H₂O₂ generation.

A novel TMD-based peroxidase-mimicking nanozyme: From naked eye detection of leukocytosis-related diseases to sensing different bioanalytes

Being emerged as alternatives to natural enzymes, nanozymes have recently drawn much attention in sensing. Herein, the first multicomponent transition metal dicalchogenide (TMD)-based nanozyme (MCFS/rGO) was synthesized by a facile hydrothermal method and characterized. This peroxidase-mimic nanozyme follows the typical Michaelis-Menten kinetics, showing a higher affinity for H₂O₂ substrate (K_m = 9 μM) compared to that of natural peroxidase (K_m = 3700 μM). The remarkable potential of the MCFS/rGO nanozyme to detect H₂O₂ provided us with a great opportunity to design some simple and fast colorimetric sensing systems. Coupling the efficient peroxidase-mimicking activity of the nanozyme with the H₂O₂ production capacity of white blood cells (WBCs) leads to the development of a novel, simple, rapid, and efficient colorimetric method to distinguish leukocytosis-related patients from healthy people by the naked eye. This pioneering diagnostic technique can also be utilized to quantitatively measure the WBC count. Moreover, we coupled the mentioned nanozyme-based system with the activity of glucose oxidase enzyme available in different types of honey samples, an innovative mechanism proved to be an effective quality indicator of the samples. Last but not least, the MCFS/rGO nanozyme is also able to determine the quantity of some biologically significant analytes, including glutathione (GSH), ascorbic acid (AA), and mercury ions (Hg²⁺), of which the limit of detection (LOD) was 9.3 nM, 22.5 nM, and 0.32 μM, respectively. Our results, however, demonstrated the superior performance of the MCFS/rGO nanozyme to determine the first two mentioned bioanalytes compared with other TMDs. Overall, this novel nanozyme-based sensor system can be considered a suitable candidate for developing multipurpose biosensors for medical and biochemical applications.

Monitoring the Release of Methylglyoxal (MGO) from Honey and Honey-Based Formulations

Methylglyoxal (MGO) is considered to be one of the vital components responsible for the anti-bacterial activity of Leptospermum spp. (Manuka) honey. While many studies have demonstrated a dose-dependent antibacterial activity for MGO in vitro, from a therapeutic viewpoint, it is also important to confirm its release from Manuka honey and also from Manuka honey-based formulations. This study is the first to report on the release profile of MGO from five commercial products containing Manuka honey using a Franz diffusion cell and High-Performance Liquid Chromatography (HPLC) analysis. The release of MGO expressed as percentage release of MGO content at baseline was monitored over a 12 h period and found to be 99.49 and 98.05% from an artificial honey matrix and NZ Manuka honey, respectively. For the investigated formulations, a time-dependent % MGO release between 85% and 97.18% was noted over the 12 h study period.

Intra-socket application of medical-grade honey after tooth extraction attenuates inflammation and promotes healing in cats

OBJECTIVES

Dental diseases are a major problem in cats and often necessitate tooth extraction. Medical-grade honey (MGH) has antimicrobial and wound-healing properties, and therefore the aim of this study was to investigate whether intra-socket application improved healing after tooth extraction. It was postulated that applying MGH would reduce inflammation, improve the viability of the surgical flap and enhance healing following tooth extraction.

METHODS

A prospective randomised controlled trial was performed in client-owned cats undergoing bilateral tooth extractions of the same element of the canine or (pre)molar tooth. A split-mouth design was used in which every animal served as its own control. After surgical extraction of the elements, the sockets on one side were filled with an MGH-based ointment (L-Mesitran Soft), whereas the contralateral side received no treatment (control). A mucoperiosteal flap was used on both sides, and simple interrupted monofilament sutures were placed. No antimicrobial drugs were administered. Clinical parameters (inflammation/redness, flap viability and wound healing) were subjectively analysed on days 3 and 7 post-extraction by a veterinarian blinded to the treatment.

RESULTS

Twenty-one cats were included. MGH significantly decreased signs of inflammation (P <0.01), improved mucoperiosteal flap viability (P <0.01) and promoted wound healing (P = 0.01), at both time points. MGH was easy to apply and there were no adverse events.

CONCLUSIONS AND RELEVANCE

Intra-socket application of MGH after tooth extraction positively affects the surgical wound, as it reduces redness, improves flap viability and enhances wound healing. Applying MGH represents a potent adjuvant therapy to support intra-oral wound healing after tooth extraction.

Antibacterial Properties of Honey Nanocomposite Fibrous Meshes

Natural substances are increasingly being developed for use in health-related applications. Honey has attracted significant interest, not only for its physical and chemical properties, but also for its antibacterial activity. For the first time, suspensions of Black Forest honeydew honey and manuka honey UMF 20+ were examined for their antibacterial properties against Escherichia coli and Staphylococcus epidermidis using flow cytometry. The inhibitory effect of honey on bacterial growth was evident at concentrations of 10, 20 and 30 v/v%. The minimum inhibitory effects of both honey types against each bacterium were also investigated and reported. Electrospray ionisation (ESI) mass spectrometry was performed on both Black Forest honeydew honey and manuka honey UMF 20+. Manuka honey had a gluconic concentration of 2519 mg/kg, whilst Black Forest honeydew honey had a concentration of 2195 mg/kg. Manuka honey demonstrated the strongest potency when compared to Black Forest honeydew honey; therefore, it was incorporated into nanofiber scaffolds using pressurised gyration and 10, 20 and 30 v/v% manuka honey-polycaprolactone solutions. Composite fibres were analysed for their morphology and topography using scanning electron microscopy. The average fibre diameter of the manuka honey-polycaprolactone scaffolds was found to range from 437 to 815 nm. The antibacterial activity of the 30 v/v% scaffolds was studied using S. epidermidis. Strong antibacterial activity was observed with a bacterial reduction rate of over 90%. The results show that honey composite fibres formed using pressurised gyration can be considered a natural therapeutic agent for various medicinal purposes, including wound-healing applications.

The Efficacy of Honey Compared to Silver Sulfadiazine for Burn Wound Dressing in Superficial and Partial Thickness Burns—A Systematic Review and Meta-Analysis

Burn dressings play a vital role in protecting the patient from infection and aiding in the wound healing process. At present, the best burn wound dressing remains unknown. This study aimed to assess the efficacy of honey versus silver sulfadiazine dressing (SSD) for the treatment of superficial and partial thickness burns. We performed a systematic review and meta-analysis using the PubMed, MEDLINE and Embase databases to find relevant randomised control trials (RCTs) for inclusion. The outcomes measures included complete burn wound healing time, the proportion of wounds rendered sterile and subjective pain relief associated with the respective dressing type. This review was completed in line with PRISMA guidelines and has been registered with PROSPERO (Study ID: CRD42022337433). All studies in the English language that assessed honey versus SSD for patients with superficial or partial thickness burns were included. Quality and risk of bias assessments were performed using the Cochrane RoB2 tool. Seven studies were identified: totalling a population of 582 patients. From three studies, meta-analysis showed no significant difference in complete wound healing time (p = 0.06). Meta-analysis from five studies highlighted an overall significant difference favouring honey dressing in the proportion of wounds rendered sterile at day 7 post-injury (OR 10.80; 95% CI [5.76, 20.26]; p < 0.00001; I2 = 88%). We conclude that honey dressings may be as or more effective than SSD in the treatment of superficial and partial thickness burn injuries. However, due to the low quality of available studies in this field, further research is necessary to establish the optimum burn dressing. Ideally, this should be conducted in the form of prospective three-arm RCTs in accordance with the CONSORT statement.

Honey: An Advanced Antimicrobial and Wound Healing Biomaterial for Tissue Engineering Applications

Honey was used in traditional medicine to treat wounds until the advent of modern medicine. The rising global antibiotic resistance has forced the development of novel therapies as alternatives to combat infections. Consequently, honey is experiencing a resurgence in evaluation for antimicrobial and wound healing applications. A range of both Gram-positive and Gram-negative bacteria, including antibiotic-resistant strains and biofilms, are inhibited by honey. Furthermore, susceptibility to antibiotics can be restored when used synergistically with honey. Honey’s antimicrobial activity also includes antifungal and antiviral properties, and in most varieties of honey, its activity is attributed to the enzymatic generation of hydrogen peroxide, a reactive oxygen species. Non-peroxide factors include low water activity, acidity, phenolic content, defensin-1, and methylglyoxal (Leptospermum honeys). Honey has also been widely explored as a tissue-regenerative agent. It can contribute to all stages of wound healing, and thus has been used in direct application and in dressings. The difficulty of the sustained delivery of honey’s active ingredients to the wound site has driven the development of tissue engineering approaches (e.g., electrospinning and hydrogels). This review presents the most in-depth and up-to-date comprehensive overview of honey’s antimicrobial and wound healing properties, commercial and medical uses, and its growing experimental use in tissue-engineered scaffolds.

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.

The role of honey in the ecology of the hive: Nutrition, detoxification, longevity, and protection against hive pathogens

Honey is the source of energy for the European honey bee, Apis mellifera. Beyond simple nutrition and a hedge against the seasonal, geographic, and chemical unpredictability of nectar, honey has properties that protect the hive against various stresses. Enzyme-mediated detoxification during honey ripening neutralizes potentially toxic phytochemicals, and bees that consume honey have enhanced tolerance to other ingested toxins. Catalase and antioxidant phenolics protect honey bees from oxidative damage caused by reactive oxygen species, promoting their longevity. Phytochemical components of honey and microRNAs have the potential to influence developmental pathways, with diet playing a large role in honey bee caste determination. Components of honey mediate stress response and promote cold tolerance during overwintering. Honey has a suite of antimicrobial mechanisms including osmotic pressure, low water activity, low pH, hydrogen peroxide, and plant-, honey bee-, and microbiota-derived compounds such as phytochemicals and antimicrobial peptides. Certain types of honey, particularly polyfloral honeys, have been shown to inhibit important honey bee pathogens including the bacteria responsible for American and European Foulbrood, the microsporidian Nosema ceranae, and the fungi responsible for Stonebrood. Understanding the diverse functional properties of honey has far-ranging implications for honey bee and hive health and management by beekeepers.

A Review of Commonly Used Methodologies for Assessing the Antibacterial Activity of Honey and Honey Products

Honey, a naturally sweet and viscous substance is mainly produced by honeybees (Apis mellifera) from flower nectar. Honey exerts a plethora of biological and pharmacological activities, namely, antioxidant, antimicrobial and anti-inflammatory activity, because of the presence of an extensive variety of bioactive compounds. The antibacterial activity is one of the most reported biological properties, with many studies demonstrating that honey is active against clinically important pathogens. As a result, beside honey’s widespread utilization as a common food and flavouring agent, honey is an attractive natural antimicrobial agent. However, the use of neat honey for therapeutic purposes poses some problems, for instance, its stickiness may hamper its appeal to consumers and health care professionals, and the maintenance of an adequate therapeutic concentration over a sufficient timeframe may be challenging due to honey liquidity and leakage. It has motivated researchers to integrate honey into diverse formulations, for example, hydrogels, dressings, ointments, pastes and lozenges. The antibacterial activity of these formulations should be scientifically determined to underscore claims of effectiveness. Some researchers have made efforts to adapt the disc carrier and suspension test to assess the antimicrobial activity of topical products (e.g., silver-based wound dressings). However, there is currently no established and validated method for determining the in vitro antimicrobial potential of natural product-based formulations, including those containing honey as the active principle. Against the backdrop of a brief discussion of the parameters that contribute to its antibacterial activity, this review provides an outline of the methods currently used for investigating the antibacterial activity of neat honey and discusses their limitations for application to honey-based formulations.

Regenerative repair of full thickness skin wound assisted by dual crosslinking percolative gel casting maneuvered alginate hydrogel embedded with honey ghee blend resembles standard cutaneous properties

We report synergism in scarless cutaneous wound repair by alginate hydrogel (HGSAG) embedded with an optimized blend of characterized Jamun honey and characterized indigenously prepared ghee. Thorough screening and characterization of honey and ghee are carried out followed by obtaining a novel dual crosslinking percolative gel casting fabrication method to come up with HGSAG showing superior chemical stability, and mechanical strength (Nanoindentation study; lowest stiffness: 0.71 ± 0.19 μN/nm), and surface morphology (SEM; highest roughness: 0.13 ± 0.04 μm) to other variants. In vitro swelling study and degradation behavior study show intermediate swelling (swelling index: 0.59 ± 0.008 in 98 h) and required restricted degradation (PBS: 73.38 ± 0.55%, DMEM: 83.48 ± 0.69% in 10 days) for HGSAG which is necessary for providing nutrients to cells and in vivo therapeutic efficacy. We observe the remarkable antibacterial efficacy of HGSAG against Staphylococcus mutans and Escherichia coli. This particular substrate also shows decent 3T3 fibroblasts viability, cell-cell communication followed by cell-matrix interaction, and proliferation compared to other variants. Molecular gene expression studies by quantitative RT-PCR technique reveal strong upregulation of collagen I, CD26, and TGF-β3 while downregulation in the case of TGF-β1 which eventually substantiates scarless wound healing potential of HGSAG. Wound closure kinetics is most rapidly and successfully underpinned by HGSAG while compared to other alternatives including marketed healing patches. Regular close monitoring using histopathological studies and real-time imaging by Swept-Source Optical Coherence Tomography of in vivo wound model treated with HGSAG come up with the fascinating result of scarless healing (HGSAG treated epithelial thickness: 62.96 ± 0.67 μm, unwounded akin epithelial thickness: 62.56 ± 0.34 μm) within 12 days of wounding. Thus, the work highlights modified and stabilized alginate hydrogel embedded with honey and ghee blend as a potential scarless full-thickness cutaneous wound healing bio-scaffold.

Antifungal Activity of Honey Samples from Khyber Pakhtunkhwa (Pakistan) as affected by Botanical Origin

The present study evaluated the antifungal activity of honey samples collected from different locations at Khyber Pakhtunkhwa (KPK, Pakistan). Disc diffusion method was used to test the antifungal potential of twenty-one (branded, unbranded, and natural comb) honey samples from the different botanical origins at different concentrations (undiluted, 10%, 30%, and 50%, w/v) against Candida albicans and Rhodotorula species. Branded, unbranded, and natural comb honey samples generate different inhibition zones (4-13 mm, 5-15 mm, and 8-17 mm) against Rhodotorula species. Candida albicans showed resistance for all tested honey samples. Minimum inhibitory concentration (MIC) against Candida albicans and Rhodotorula species were 53.33%-88.12% and 1.76%-90.22% for branded, 61.3% – 93.8% and 9.90% – 95.5% for unbranded, and 67.1%-96.8% and 6.39%-98.8% for natural comb honey. In conclusion, natural comb honey from Khyber Pakhtunkhwa may have antifungal therapeutic potential and could be a useful source for generating functional food.

Antimicrobial Evaluation of Various Honey Types against Carbapenemase-Producing Gram-Negative Clinical Isolates

The development of antibiotic resistance is a major public health issue, as infections are increasingly unresponsive to antibiotics. Emerging antimicrobial resistance has raised researchers’ interest in the development of alternative strategies using natural compounds with antibacterial activity, like honey, which has emerged as an agent to treat several infections and wound injuries. Nevertheless, the antibacterial effect of honey was mostly evaluated against Gram-positive bacteria. Hence, the objective of our study was to evaluate the antibacterial activity, as well as the physicochemical parameters, of genuine Greek honeys against multidrug-resistant Gram-negative pathogenic bacteria. In this vein, we aimed to study the in vitro antibacterial potential of rare Greek honeys against Verona integron-encoded metallo-β-lactamase (VIM)- or Klebsiella pneumoniae carbapenemase-producing multidrug-resistant Gram-negative pathogens. Physicochemical parameters such as pH, hydrogen peroxide, free acidity, lactonic acid, total phenols total flavonoids, free radical scavenging activities, tyrosinase enzyme inhibitory activity and kojic acid were examined. Moreover, the antimicrobial activity of 10 different honey types was evaluated in five consecutive dilutions (75%, 50%, 25%, 12.5% and 6.25%) against the clinical isolates by the well diffusion method, as well as by the determination of the minimum inhibition concentration after the addition of catalase and protease. Almost all the physicochemical parameters varied significantly among the different honeys. Fir and manuka honey showed the highest values in pH and H₂O₂, while the free acidity and lactonic acid levels were higher in chestnut honey. Total phenols, total flavonoids and free radical scavenging activities were found higher in cotton, arbutus and manuka honey, and finally, manuka and oregano honeys showed higher tyrosinase inhibition activity and kojic acid levels. The antimicrobial susceptibility depended on the type of honey, on its dilution, on the treatment methodology and on the microorganism. Arbutus honey was the most potent against VIM-producing Enterobacter cloacae subsp. dissolvens in 75% concentration, while fir honey was more lethal for the same microorganism in the 25% concentration. Many honeys outperformed manuka honey in their antibacterial potency. It is of interest that, for any given concentration in the well diffusion method and for any given type of honey, significant differences were not detected among the four multidrug-resistant pathogens, which explains that the damaging effect to the bacterial cells was the same regardless of the bacterial species or strain. Although the antimicrobial potency of different honey varieties dependents on their geographical origin and on their compositional differences, the exact underlying mechanism remains yet unclear.

Interaction between properties of commercial Australian honey and saliva: in vitro exploratory study of a potential mechanism in the treatment of oral mucositis

OBJECTIVES

Oral mucositis is a debilitating oncology treatment side effect, with honey identified as a viable management option due to established wound-healing abilities. However, effects of saliva on properties attributed to honey's wound-healing abilities is unknown. Therefore, this study aimed to identify interactions between saliva, and antioxidant characteristics and pH of honey.

METHODS

Saliva was collected from 15 healthy participants (Females n=9; mean age=34.1 ± 11.2 years). Centrifuged salivary supernatant, whole saliva, and water were independently used to dilute commercial Australian honeys (n=42). Antioxidant characteristics (DPPH and FRAP) and pH of diluted honeys were analysed, and differences between dilution conditions were determined.

RESULTS

Honey and saliva dilutions increased antioxidant characteristics compared to water, and addition of honey to saliva reduced pH compared with saliva alone. There were significant differences between dilutions for FRAP and pH, and water and salivary conditions for DPPH (p<0.001). No difference was observed between salivary conditions for DPPH (p=0.931), suggesting smaller cells remaining in the supernatant possess antioxidant abilities. However, differences observed for FRAP suggest precipitable molecules, including epithelial and food debris, could provide additional antioxidant power.

CONCLUSIONS

The addition of saliva to honey may support properties attributed to honey's wound-healing abilities and should be considered in the context of oral mucositis management.

Review of guidelines for functional claw trimming and therapeutic approach to claw horn lesions in cattle

Lameness is one of the most pressing health and welfare problems in cattle, especially on dairy farms. The most common cause of lameness is claw pathology, often due to lack of appropriate functional claw trimming. Functional claw trimming restores the physiological shape of the claws and distributes weight properly between the claws and over the claw weight-bearing surface. It also allows closer examination of the claws for early signs of pathology. The methods of functional claw trimming described in the previous century are still applicable today, considering some recent findings on the subject. It is essential not to over-trim the claws and to maintain strict hygiene of the trimming tools. Claw horn pathology in the early stages is usually treated effectively by therapeutic claw trimming alone. The stoic nature of cattle and their natural tendency to hide pain often result in delayed treatment of claw diseases, leading to more advanced stages of disease/pathology associated with higher-grade lameness. This situation often leads to the development of neuropathic pain and hyperalgesia requiring multimodal treatment. Because claw horn diseases are multifactorial, veterinarians and others involved in animal management must be familiar with the preventive measures available to improve claw health in a cattle herd. Further research to improve claw horn quality and effectively control/prevent claw infections without polluting the environment or negatively affecting worker and animal health is still needed. This article reviews the latest knowledge on functional claw trimming and treatment of the most common claw horn diseases in cattle.

The bioactive, antioxidant, antibacterial, and physicochemical properties of a range of commercially available Australian honeys

Honey is a supersaturated sugar solution produced from plant nectar, with its composition influenced by geographic and floral origins, and with several properties contributing to its health-related abilities. This study aimed to determine the bioactive composition, antioxidant characteristics, antibacterial activity, and physicochemical properties of commercial Australian honeys. In total, 42 commercial Australian honeys were selected, and categorised according to front-label descriptions. Honeys were analysed: quality (Hydroxymethylfurfural); colour (colour intensity, L*,a*,b*); bioactive composition (phenolic, flavonoid, and carotenoid content); antioxidant characteristics (DPPH, CUPRAC, FRAP); antibacterial activity (MIC50); physicochemical properties (pH, TSS, viscosity, a w). Colour intensity correlated with each assessed bioactive compound and antioxidant characteristic (p ≤ 0.001). MIC50 (S. aureus) was associated with FRAP and a w, suggesting mechanisms of action for honey's antibacterial activity. Manuka-type honeys had higher colour intensity (1440 (98.5) mAU) than other categories (p ≤ 0.05), and consistently higher bioactive and antioxidant properties. This provides the potential to inform antioxidant-related health outcomes.

Beehive Products as Antibacterial Agents: A Review

Honeybees are one of the most marvelous and economically beneficial insects. As pollinators, they play a vital role in every aspect of the ecosystem. Beehive products have been used for thousands of years in many cultures for the treatment of various diseases. Their healing properties have been documented in many religious texts like the Noble Quran and the Holy Bible. Honey, bee venom, propolis, pollen and royal jelly all demonstrated a richness in their bioactive compounds which make them effective against a variety of bacterial strains. Furthermore, many studies showed that honey and bee venom work as powerful antibacterial agents against a wide range of bacteria including life-threatening bacteria. Several reports documented the biological activities of honeybee products but none of them emphasized on the antibacterial activity of all beehive products. Therefore, this review aims to highlight the antibacterial activity of honey, bee venom, propolis, pollen and royal jelly, that are produced by honeybees.

Quantification of Hydrogen Peroxide in Cretan Honey and Correlation with Physicochemical Parameters

The aim of the present study is to quantify hydrogen peroxide, generated from various types of honey produced in Crete, as a potent antimicrobial agent, and establish any correlation with their physicochemical parameters. The basic physicochemical parameters (diastase activity, HMF content, moisture, electrical conductivity, color, and sugars) of 30 authentic honey samples were determined. The concentration of hydrogen peroxide in all samples was found to be within the range 0.010-0.092 mM. The known correlation between the electrical conductivity and the color of honey was confirmed in this study. Univariate and multivariate statistics applied to the results indicate that the results can be used to discriminate honey sample groups of different botanical origins.

Comparison of topical honey and povidone iodine-based dressings for wound healing: a systematic review and meta-analysis

OBJECTIVES

In this review and meta-analysis, we analyse the evidence to compare the efficacy of honey and povidone iodine-based dressings on the outcome of wound healing.

METHOD

A systematic literature search was performed using PRISMA guidelines in academic databases including MEDLINE, Scopus, Embase and CENTRAL. A meta-analysis was carried out to assess the effect of honey and povidone iodine-based dressings on mean healing duration, mean hospital stay duration and visual analogue scale (VAS) score of pain.

RESULTS

From the search, 12 manuscripts with a total of 1236 participants (mean age: 40.7±11.7 years) were included. The honey-based dressings demonstrated a medium-to-large effect in reduction of mean healing duration (Hedge's g: -0.81), length of hospital stay (-3.1) and VAS score (-1.2) as compared with the povidone iodine-based dressings. We present evidence (level 1b) in favour of using honey for improvement of wound recovery as compared with povidone iodine.

CONCLUSION

This review and meta-analysis demonstrate beneficial effects of honey-based dressings over povidone iodine-based dressings for wound recovery.

The Sardinian Bitter Honey: From Ancient Healing Use to Recent Findings

Sardinian bitter honey, obtained from the autumnal flowering of the strawberry tree (Arbutus unedo L.), has an old fame and tradition in popular use, especially as a medicine. Its knowledge dates back over 2000 years, starting from the Greeks and Romans to the present day. There are many literary references from illustrious personalities of the past such as Cicero, Horace, Virgil, and Dioscorides, until recent times, associated with the peculiar anomaly of its taste, which lends itself to literary and poetic metaphors. The curiosity of its bitter taste is also what led to the first studies starting in the late 1800s, aimed to reveal its origin. Other studies on its botanical source and characteristics have been carried out over time, up to the most recent investigations, which have confirmed its potential for use in the medical field, thanks to its antioxidant, antiradical, and cancer-preventing properties. These benefits have been associated with its phenolic component and in particular with the prevailing phenolic acid (homogentisic acid). Later, other strawberry tree honeys from the Mediterranean area have also shown the same properties. However, Sardinian bitter honey maintains its geographical and historical identity, which is recognized by other Mediterranean cultures.

Portuguese honeys as antimicrobial agents against Candida species

BACKGROUND AND AIM

Honey has been recognized worldwide for its antioxidant, anti-tumor, anti-inflammatory and antimicrobial properties. Among them, the antifungal properties associated to honey make it an attractive alternative treatment for Candida-associated infections, particularly for topical application to the mucous membranes and skin. In this sense, the main purpose of this work was to evaluate physicochemical properties of five Portuguese honeys and Manuka honey (an Australian honey with well recognized medical proprieties, used as control) and to evaluate the antifungal activity in Candida species planktonic and biofilm assays.

EXPERIMENTAL PROCEDURE

Pollen analysis, pH determination, color, concentration of protein and methylglyoxal, conductivity, total phenolics and flavonoids, hydrogen peroxide concentration, and characterization by differential scanning calorimetry in honey samples were determined. Additionally, the effect of honeys on planktonic growth of Candida was initially evaluated by determination of the minimum inhibitory concentrations. Then, the same effect of those honeys was evaluated in biofilms, by Colony Forming Units enumeration.

RESULTS AND CONCLUSION

It has been shown that Portuguese heather (Erica cinereal) honey presented the most similar physicochemical properties to manuka honey (specially phenolic and flavonoids contents). The five Portuguese honeys under study, presented in general a potent activity against planktonic multi-resistant yeast pathogens (several clinical isolates and reference strains of Candida species) and S. aureus and P. aeruginosa bacteria cultures. Additionally, it was also concluded that Portuguese heather honey (50% and 75% (w/v)) can also act as a good Candida species biofilm reducer, namely for C. tropicalis.

Honey-incorporated nanofibre reduces replicative senescence of umbilical cord-derived mesenchymal stem cells

Umbilical cord-derived mesenchymal stem cells (UCDMSC) are attractive candidates for cell-based regenerative medicine. However, they are susceptible to replicative senescence during repetitive passaging for in-vitro expansion and induced senescence in an oxidative, inflammatory microenvironment in vivo. Aim of this study is to investigate if honey-incorporated matrices can be employed to reduce senescence of UCDMSC. Matrices were prepared by electrospinning solutions of honey with poly-vinyl alcohol (PVA). PVA:honey matrices exhibited free radical scavenging activity. Culture of UCDMSC on PVA:honey matrices showed improvement in cell proliferation compared to pure PVA nanofibres. Expression of vimentin indicated that mesenchymal phenotype is preserved after culturing on these matrices. Further, UCDMSC were serially subcultured and cells of two passages (P2 and P6) were evaluated for reactive oxygen species (ROS) load and senescence parameters. P6 cells showed a higher ROS load and β-galactosidase (β-gal) positive senescent cells compared to P2. However, culturing on PVA:honey substrates significantly reduced both ROS and β-gal markers compared to cells on PVA substrates. Honey contains several antioxidant and anti-inflammatory components, which can reduce the ROS-related senescence. Thus, it is concluded that honey containing nanofibres can be effective substrates for stem cell-based wound healing and regenerative medicine.

Use of a model to understand the synergies underlying the antibacterial mechanism of H2O2-producing honeys

Honey has been valued as a powerful antimicrobial since ancient times. However, the understanding of the underlying antibacterial mechanism is incomplete. The complexity and variability of honey composition represent a challenge to this scope. In this study, a simple model system was used to investigate the antibacterial effect of, and possible synergies between, the three main stressors present in honey: sugars, gluconic acid, and hydrogen peroxide (H₂O₂), which result from the enzymatic conversion of glucose on honey dilution. Our results demonstrated that the synergy of H₂O₂ and gluconic acid is essential for the antibacterial activity of honey. This synergy caused membrane depolarization, destruction of the cell wall, and eventually growth inhibition of E. coli K-12. The presence of H₂O₂ stimulated the generation of other long-lived ROS in a dose-dependent manner. Sugars caused osmosis-related morphological changes, however, decreased the toxicity of the H₂O₂/gluconic acid. The susceptibility of catalase and general stress response sigma factor mutants confirmed the synergy of the three stressors, which is enhanced at higher H₂O₂ concentrations. By monitoring cellular phenotypic changes caused by model honey, we explained how this can be bactericidal even though the antimicrobial compounds which it contains are at non-inhibitory concentrations.

A Review on Evidence-Based Treatments for Meibomian Gland Dysfunction

OBJECTIVES

To evaluate recent studies on available therapies for meibomian gland dysfunction (MGD).

METHODS

A literature search on recent publications, within the last five years, concerning treatment options for MGD was performed.

RESULTS

A total of 35 articles were reviewed after curation by the authors for relevance. In general, all modalities of treatments were shown to have clinical efficacy in alleviating dry eye signs and symptoms, although the extent of improvement and persistency of outcomes varied between the different treatments. Evidence from published studies demonstrate that thermal pulsation produces the longest lasting effect per treatment, but it also incurs the highest per-treatment cost. Reusable methods for warm compress with lipid/semi-fluorinated alkane-containing eye drops are recommended as first-line treatment for mild-to-moderate dry eye patients, because this option is most technically feasible and cost-effective in clinical practice. Intense pulsed light (IPL) therapy and thermal pulsation may be suitable as second line for patients unresponsive to warm compress therapy; however, their respective limitations need to be considered. For refractory MGD with features of periductal fibrosis or severe blepharitis, supplementary treatment with meibomian gland probing or oral antibiotics may be used.

CONCLUSIONS

All eight forms of treatments, including self-applied eyelid warming, thermal pulsation, IPL, MG probing, antibiotics, lipid-containing eye drops, and perfluorohexyloctane, were effective against MGD, although with varying extent of clinical improvements. A better understanding on the mechanisms of actions may guide physicians to make better treatment decisions targeting the root causes.

Exposure to a Manuka Honey Wound Gel Is Associated With Changes in Bacterial Virulence and Antimicrobial Susceptibility

The use of manuka honey for the topical treatment of wounds has increased worldwide owing to its broad spectrum of activity towards bacteria in both planktonic and biofilm growth modes. Despite this, the potential consequences of bacterial exposure to manuka honey, as may occur during the treatment of chronic wounds, are not fully understood. Here, we describe changes in antimicrobial susceptibility and virulence in a panel of bacteria, including wound isolates, following repeated exposure (ten passages) to sub-inhibitory concentrations of a manuka honey based wound gel. Changes in antibiotic sensitivity above 4-fold were predominantly related to increased vancomycin sensitivity in the staphylococci. Interestingly, Staphylococcus epidermidis displayed phenotypic resistance to erythromycin following passaging, with susceptibility profiles returning to baseline in the absence of further honey exposure. Changes in susceptibility to the tested wound gel were moderate (≤ 1-fold) when compared to the respective parent strain. In sessile communities, increased biofilm eradication concentrations over 4-fold occurred in a wound isolate of Pseudomonas aeruginosa (WIBG 2.2) as evidenced by a 7-fold reduction in gentamicin sensitivity following passaging. With regards to pathogenesis, 4/8 bacteria exhibited enhanced virulence following honey wound gel exposure. In the pseudomonads and S. epidermidis, this occurred in conjunction with increased haemolysis and biofilm formation, whilst P. aeruginosa also exhibited increased pyocyanin production. Where virulence attenuation was noted in a passaged wound isolate of S. aureus (WIBG 1.6), this was concomitant to delayed coagulation and reduced haemolytic potential. Overall, passaging in the presence of a manuka honey wound gel led to changes in antimicrobial sensitivity and virulence that varied between test bacteria.

Expression of Aspergillus niger glucose oxidase in Pichia pastoris and its antimicrobial activity against Agrobacterium and Escherichia coli

The gene encoding glucose oxidase from Aspergillus niger ZM-8 was cloned and transferred to Pichia pastoris GS115, a transgenic strain P. pastoris GS115-His-GOD constructed. The growth curve of P. pastoris GS115-His-GOD was consistent with that of Pichia pastoris GS115-pPIC9K under non-induced culture conditions. Under methanol induction conditions, the growth of the GOD-transgenic strain was significantly lowered than P. pastoris GS115-pPIC9K with the induced-culture time increase, and the optical densities of GOD-transgenic strain reached one-third of that of the P. pastoris GS115-pPIC9K at 51 h. The activity of glucose oxidase in the cell-free supernatant, the supernatant of cell lysate, and the precipitation of cell lysate was 14.3 U/mL, 18.2 U/mL and 0.48 U/mL, respectively. The specific activity of glucose oxidase was 8.3 U/mg, 6.52 U/mg and 0.73 U/mg, respectively. The concentration of hydrogen peroxide formed by glucose oxidase from supernatant of the fermentation medium, the supernatant of the cell lysate, and the precipitation of cell lysate catalyzing 0.2 M glucose was 14.3 μg/mL, 18.2 μg/mL, 0.48 μg/mL, respectively. The combination of different concentrations of glucose oxidase and glucose could significantly inhibit the growth of Agrobacterium and Escherichia coli in logarithmic phase. The filter article containing supernatant of the fermentation medium, supernatant of the cell lysate, and precipitation of cell lysate had no inhibitory effect on Agrobacterium and E. coli. The minimum inhibitory concentration of hydrogen peroxide on the plate culture of Agrobacterium and E. coli was 5.6 × 10³ μg/mL and 6.0 × 10³ μg/mL, respectively.

A current perspective on hydrogen peroxide production in honey. A review

Hydrogen peroxide plays a key role in honey antibacterial activity. The production of H₂O₂ in honey requires glucose oxidase (GOx) that oxidizes glucose to gluconolactone and reduces molecular oxygen to hydrogen peroxide. The content of GOx of honeybee origin was believed to be the main predictor of H₂O₂ concentration in honey. The observed variations in H₂O₂ levels among honeys questioned however the direct GOx-H₂O₂ relationship and left its absence opened for exploration. Here, we evaluated principal causes underlying the imbalance in the quantitative enzyme-product relationship with respect to: (a) enzyme and the product inactivation or destruction by honey compounds; (b) non-enzymatic pathway of H₂O₂ formation, and (c) a potential contribution of enzymes with GOx activity originating from nectars and microorganisms inhabiting honey. We also bring new facts on the relationship between honey colloidal structure and H₂O₂ production that change our traditional understanding of honey function as antimicrobial agent.

Systematic review of natural and miscellaneous agents, for the management of oral mucositis in cancer patients and clinical practice guidelines - part 2: honey, herbal compounds, saliva stimulants, probiotics, and miscellaneous agents

OBJECTIVE

To update the clinical practice guidelines for the management of oral mucositis (OM) that were developed by the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO). This part focuses on honey, herbal compounds, saliva stimulants, probiotics, and miscellaneous agents.

METHODS

A systematic review was conducted by the Mucositis Study Group of MASCC/ISOO. The body of evidence for each intervention, in each clinical setting, was assigned an evidence level. The findings were added to the database used to develop the 2014 MASCC/ISOO clinical practice guidelines. Based on the evidence level, one of the following guidelines were determined: Recommendation, Suggestion, No Guideline Possible.

RESULTS

A total of 78 papers were identified within the scope of this section, of which 49 were included in this review and merged with nine publications that were reported in the previous guidelines update. A new Suggestion was made for honey (combined topical and systemic delivery) for the prevention of OM in head and neck cancer patients receiving radiotherapy with or without chemotherapy. A new Suggestion clarified that chewing gum is not effective for the prevention of OM in pediatric patients with hematological or solid cancer treated with chemotherapy. No guideline was possible for other interventions.

CONCLUSIONS

Numerous natural products and herbal remedies were studied for the management of OM. Of the agents reviewed in this systematic review, a guideline in favor was made for honey (combined topical and systemic), while a guideline against was made for chewing gum. Additional research is warranted to clarify the potential of other interventions.

Relationship among the minor constituents, antibacterial activity and geographical origin of honey: A multifactor perspective

Some minor constituents of honey samples were determined through a fluorometric-chemical characterization method and related multifactorially with their antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa and with their geographical origin. Rotated principal component analysis identified five significant components in honey: three related to antibacterial activity and linked to phenolic compounds; Maillard products; proteins; the concentration of H₂O₂ at 3 and 24 h of incubation; and a tyrosine-containing entity. On the other hand, five constituents (phenolic compounds were the most relevant) allowed the classification of honey samples by geographical origin with 87% certainty. The results showed that phenolic compounds and Maillard products are related to the sustained production of H₂O₂ over time, which in turn boosts the antibacterial activity of honey. Native flora could promote this capability. The results showed the effect of geographic origin on the content of the analyzed minor constituents of honey, particularly phenolic compounds.

In vitro antimicrobial activities of Saudi honeys originating from Ziziphus spina-christi L. and Acacia gerrardii Benth. trees

Honeys originating from Sidr (Ziziphus spina-christi L.) and Talh (Acacia gerrardii Benth.) trees in Saudi Arabia exhibited substantial antimicrobial activity against pathogenic gram-positive bacteria (Bacillus cereus, Staphylococcus aureus), gram-negative bacteria (Escherichia coli, Salmonella enteritidis), and a dermatophytic fungus (Trichophyton mentagrophytes). The diameter of zones of inhibition represents the level of antimicrobial potency of the honey samples. Precisely, Talh honey showed significantly higher antibacterial activity against all tested bacteria than Sidr honey. The antifungal activity of Talh and Sidr honey types was significantly at par against a dermatophytic fungus. The water-diluted honey types (33% w/v) significantly induced a rise in the antimicrobial activity from that of the natural nondiluted honeys. Microbial strains displayed differential sensitivity; gram-positive bacteria were more sensitive and presented larger inhibition zones than gram-negative bacteria and the fungus. The sensitivity was highest in B. cereus and S. aureus, followed by T. mentagrophytes, E. coli, and S. enteritidis. The antimicrobial activity of water-diluted honeys (Sidr and Talh) was high than that of broad-spectrum antibacterial antibiotics (tetracycline and chloramphenicol) against bacterial strains, but these honeys were relativity less potent than antifungal antibiotics (flucoral and mycosat) against a fungal strain. Our findings indicate the antimicrobial potential of Saudi honeys to be considered in honey standards, and their therapeutic use as medical-grade honeys needs further investigations.

Agastache honey has superior antifungal activity in comparison with important commercial honeys

There is an urgent need for new effective antifungal agents suitable for the treatment of superficial skin infections, since acquired resistance of fungi to currently available agents is increasing. The antifungal activity of mono-floral Agastache honey and commercially available honeys were tested against dermatophytes (T. mentagrophytes and T. rubrum) and C. albicans (ATCC 10231 and a clinical isolate) by agar well diffusion and micro-dilution (AWD and MD). In AWD and MD assays, Agastache honey was effective at 40% concentration against dermatophytes (zone diameter, 19.5–20 mm) and C. albicans with the same MIC and MFC values indicating fungicidal activity. Tea tree honey was effective at 80% concentration (zone diameter, 14 mm) against dermatophytes and at 40% concentration against T. mentagrophytes and C. albicans. Manuka was effective at 80% concentration only against T. mentagrophytes (zone diameter, 12 mm) and at 40% against T. rubrum and C. albicans with fungistatic activity. Similar to the AWD results, Jelly bush, Super Manuka, and Jarrah showed no activity against dermatophytes but showed some activity against C. albicans. Headspace volatiles of six honeys were isolated by SPME and identified by GC-MS. The characteristic chemical markers for each honey were as follows: Agastache- Phenol, 2,4-bis(1,1-dimethylethyl) and Estragole; Manuka and Tea-tree- Acetanisole and Methyl 3,5-dimethoxybenzoate; Jelly bush- Linalool and Nonanal; Super Manuka- Methyl 3,5-dimethoxybenzoate and Nonanal; Jarrah- Isophorone and Nonanoic acid. Overall, analysis of the bioactive compound content and antifungal activity of Agastache honey indicated possible use as an antifungal agent for management of superficial fungal infections.

Efficacy of non-antibiotic treatment options for digital dermatitis on an organic dairy farm

The objective of this study was to evaluate the efficacy of two non-antibiotic treatment options for digital dermatitis (DD) on an organic certified dairy farm. A randomized clinical trial was conducted using 70 multiparous Holstein cows with an early DD lesion at a USDA certified organic dairy farm in Northern Colorado, USA. Cows were enrolled in the study based on the presence of early DD lesions (scores M1 and M2) and randomly assigned to one of three treatments: (1) topical application of copper sulfate and iodine (CUI); (2) topical application of honey and iodine (HOI); and (3) control subject to no treatment (CON). Cows were evaluated at enrolment and on days 3, 12, 28, and 120 post treatment for pain and lesion size and received a locomotion and a lesion score. Cure was defined as the transition from active to non-active stages (M1/M2 to M0 or M4). The formulations had variable effects on the treatment of DD. The cure rate was numerically higher for CUI on all follow up days. The proportion of cows experiencing pain on d3 after treatment was greater in CON, followed by HOI and CUI. However, this proportion increased in HOI during the follow up period. The CUI group had a greater reduction in lesion size and larger lesions persisted in HOI. Non-antibiotic treatment formulations were partially effective in the treatment of DD in organic dairy cows: The two non-antibiotic formulations resulted in an earlier transition to mature lesions compared with the control group. The CUI combination was the most effective treatment in reducing lesion size, pain, and lameness in affected cows. However, this combination had short-term efficacy, which did not persist throughout the duration of the study. The HOI combination produced only transient reduction in lesion size.

Anti-biofilm effects and characterisation of the hydrogen peroxide activity of a range of Western Australian honeys compared to Manuka and multifloral honeys

The antibacterial activity of honeys derived from the endemic flora of the southwest corner of Western Australia, including the trees Jarrah (Eucalyptus marginata) and Marri (Corymbia calophylla), remains largely unexplored. Investigation of these honeys showed minimum inhibitory concentrations (MICs) of 6.7-28.0% (w/v) against Gram positive and negative bacteria. Honey solutions showed enhanced antibacterial activity after hydrogen peroxide was allowed to accumulate prior to testing, with a mean MIC after accumulation of 14.3% compared to 17.4% before accumulation. Antibacterial activity was reduced after treatment with catalase enzyme, with a mean MIC of 29.4% with catalase compared to 15.2% without catalase. Tests investigating the role of the Gram negative outer membrane in honey susceptibility revealed increases in activity after destabilisation of the outer membrane. Honeys reduced both the formation of biofilm and the production of bacterial pigments, which are both regulated by quorum sensing. However, these reductions were closely correlated with global growth inhibition. Honey applied to existing biofilms resulted in decreased metabolic activity and minor decreases in viability. These results enhance our understanding of the mechanisms of antibacterial action of Jarrah and Marri honeys, and provide further support for the use of honey in the treatment of infected wounds.

A cost-effective colourimetric assay for quantifying hydrogen peroxide in honey

Honey is a natural product with many beneficial properties including antimicrobial action. Production of hydrogen peroxide (H₂O₂) in diluted honey is central to this action. Here, we describe an optimized method for measuring levels of H₂O₂ in honey. This method is based on established methods, with the level of dilution, the time between dilution and reading the assay, and aeration of the samples during the assay identified as critical points for ensuring reliability and reproducibility. The method is cost-effective and easy to perform using common laboratory equipment. Using this method, we quantified the hydrogen peroxide content of five different, unprocessed polyfloral honeys collected in NC, USA. Our results show that H₂O₂ production by these honeys varies greatly, with some samples producing negligible levels of H₂O₂. We assessed the effect of colour on the assay by measuring the recovery of spiked H₂O₂ from light and dark honey and from serially diluted dark corn syrup, and found the amount of H₂O₂ that could be detected was lower in dark corn syrup and darker honey samples.

A Critical Review and Perspective of Honey in Tissue Engineering and Clinical Wound Healing

Significance: Historically, honey has been regarded as a potent agent in bacterial inhibition and wound healing. An increased prevalence of antibiotic resistant pathogens spurred an initial resurgence in honey's clinical popularity, with it quickly finding a place in wound care and regenerative medicine. However, this renewed usage demanded a need for improved delivery and overall research of its bioactive properties. This review provides an overview of the antibacterial properties and clinical use of honey. Recent Advances: The past and present clinical use of honey is noted, focusing specifically on burns and ulcers, as these are the most common applications of the natural agent. While honey is often used without modification clinically, there are also commercially available products ranging from dressings to gels, which are discussed. Critical Issues: Despite these products growing in popularity, the need for improved delivery and a structure to support wound healing could improve the treatment method. Future Directions: Tissue engineering scaffolds can provide an alternative method of honey delivery with research focusing primarily on electrospun scaffolds, hydrogels, and cryogels. Current studies on these scaffolds are discussed with respect to their advantages and potential for future clinical work. Overall, this review provides a comprehensive overview of the properties of honey, its current use in wound healing, and the potential for future incorporation into tissue-engineered scaffolds to provide an innovative wound healing agent.

Antibacterial Potency of Honey

Despite the developments in controlling infectious disease around the world, they are still the second biggest cause of morbidity and mortality due in part to the increase in drug resistance among large numbers of the bacterial strains. This means that new strategies are needed to prevent and treat infectious disease. As a result, several ancient methods have been re-evaluated and the substances/procedures employed historically to cure diseases are now attracting renewed scientific attention. Honey is one such product that used to be widely used to combat bacteria. This review covers the antibacterial activity of honey, its use in the treatment of infection and diseases, and the features that are relevant to its activity.