Role of Honey in Topical and Systemic Bacterial Infections

Exploring the Nutritional Value and Health Benefits of Honey from the Portuguese Protected Area of Montesinho Natural Park

The main objective of this study was to provide an overview of the potential health-promoting properties of honeys collected at specific apiary locations from the protected area of Montesinho Natural Park (MNP), by analyzing their amino acid and polyphenolic profiles, and their biological properties, and comparing them with the renowned Manuka honey. The results revealed differences in total phenolic content among the samples examined and between sampling campaigns, with values ranging from 55.6 to 225 mg gallic acid equivalents (GAE) per 100 g of honey, compared to 57.2 mg GAE/100 g for Manuka honey. Gallic acid, neochlorogenic acid, and catechin were the key phenolics of MNP honey samples. MNP honey exhibited high levels of essential amino acids (phenylalanine, lysine, and valine), strong antioxidant and antimicrobial activities, moderate enzyme inhibition, and high proline content in some locations. These results highlight the exceptional nutritional and therapeutic potential of MNP honey.

Effect of Acacia Honey on Serum Uric Acid Level and Liver Injury in Rats

Objective

Honey is generally considered to be a natural product with rich nutritional value. However, the fructose contained in honey is harmful to the liver. This study aims to observe the effect of acacia honey (AH) on serum uric acid and liver injury in potassium oxonate model rats after drinking AH aqueous solution.

Materials and methods

Sixty male Sprague-Dawley (SD) rats were selected and randomly divided into control group (CON group), potassium oxonate model group (OA model group), 10% fructose group (10%F group) and different concentration AH groups (25%, 12.5% and 6.25% AH groups). 100 mg/kg OA solution combined with fructose solution or AH solution was administered to gavage model rats. After the 4 weeks test, blood and liver tissues were collected, serum uric acid content, biochemical indexes, activities of alanine transaminase and alanine transaminase were determined, and liver histological sections were observed.

Results

AH can significantly increase serum uric acid level, liver weight and liver to body weight ratio ( p < 0.05). The levels of serum triglyceride (TG), free fatty acid (FFA), and high-density fatty acid cholesterol (HDL-C) were elevated in 25% and 12.5% AH groups compared with CON group or OA model group ( p < 0.05), but serum levels of TG, FFA, HDL-C, total cholesterol (T-CHO) and low density lipoprotein cholesterol (LDL-C) were significantly increased in 6.25%AH group ( p < 0.05).

Conclusion

AH can cause fatty liver disease in all rats in a dose dependent manner. In the dose range of the present study, AH can induce hyperuricemia, hypertriglyceridemia and fatty liver disease.

Honey as a Natural Nutraceutical: Its Combinational Therapeutic Strategies Applicable to Blood Infections-Septicemia, HIV, SARS-CoV-2, Malaria

Honey is a natural substance that has existed alongside humanity since the time of antiquity, acting then as a source of nutrition, as well as a source of medicinal aid for people. Ancient civilizations from multiple nations of the world, from ancient China to ancient Greece and Egypt, utilized the supposed healing properties of honey to treat lacerations and wounds, as well as for internal pathologies such as intestinal disease. At present, honey has entered the modern scientific research program in search of novel antibiotics. In recent research, honey has demonstrated its potential use for static and/or cidal effects on microbial strains which are becoming resistant to chemical antibiotics. Additionally, the use of honey as an agent of treatment for more severe infections, namely blood infections pertaining to septicemia, HIV, and SARS-CoV-2, as well as parasitic infections such as malaria, have also been investigated in recent years. In this article, the literature has been reviewed on some of the therapeutic properties of natural nutraceutical honey, where it has been observed to act as a potential ameliorating agent; reducing the severity of such conditions that may amplify a disease, as well as reducing the progression of the disease and its symptoms.

Both Manuka and Non-Manuka Honey Types Inhibit Antibiotic Resistant Wound-Infecting Bacteria

Postoperative infections are a major concern in United States hospitals, accounting for roughly 20% of all hospital-acquired infections yearly. Wound-infecting bacteria, in particular, have a high rate of drug resistance (up to 65%), creating life-threatening complications. Manuka honey, native to New Zealand, has been FDA-approved for wound treatment in the United States after studies demonstrated its ability to inhibit a variety of bacterial species and facilitate wound healing. The aim of this study was to identify alternative (non-manuka) honey types that can be specifically used against antibiotic resistance bacteria in wound infections. We utilized a honey-plate method to measure the minimum inhibitory concentration (MIC) of honey to avoid the limitations of agar diffusion, where large, nonpolar polyphenols (which will not diffuse efficiently) play an important role in bioactivity. This study demonstrated that there are several alternative (non-manuka) honey types, particularly fresh raw Arkansas wildflower honeys, that comparably inhibit the growth of the antibiotic-resistant bacterial species specifically implicated in wound infections. Concentrations of 10-30% honey inhibited the growth of the highly antibiotic-resistant organisms colloquially referred to as "superbugs", which the WHO declared in 2017 to be in critical need of new antibiotics. There was no statistical difference between manuka honey and fresh summer Arkansas wildflower honey in overall bacterial inhibition. These results could transform wound care in the United States, where manuka honey can be expensive and difficult to obtain and where antibiotic resistance remains a troubling concern for wound treatment.

Effects of Probiotics in the Management of Infected Chronic Wounds: From Cell Culture to Human Studies

BACKGROUND

Chronic wounds are commonly associated with polymicrobial biofilm infections. In the last years, the extensive use of antibiotics has generated several antibiotic-resistant variants. To overcome this issue, alternative natural treatments have been proposed, including the use of microorganisms like probiotics. The aim of this manuscript was to review current literature concerning the application of probiotics for the treatment of infected chronic wounds.

METHODS

Relevant articles were searched in the Medline database using PubMed and Scholar, using the keywords "probiotics" and "wound" and "injuries", "probiotics" and "wound" and "ulcer", "biofilm" and "probiotics" and "wound", "biofilm" and "ulcer" and "probiotics", "biofilm" and "ulcer" and "probiotics", "probiotics" and "wound".

RESULTS

The research initially included 253 articles. After removal of duplicate studies, and selection according to specific inclusion and exclusion criteria, 19 research articles were included and reviewed, accounting for 12 in vitro, 8 in vivo studies and 2 human studies (three articles dealing with animal experiments included also in vitro testing). Most of the published studies about the effects of probiotics for the treatment of infected chronic wounds reported a partial inhibition of microbial growth, biofilm formation and quorum sensing.

DISCUSSION

The application of probiotics represents an intriguing option in the treatment of infected chronic wounds with multidrug-resistant bacteria; however, current results are difficult to compare due to the heterogeneity in methodology, laboratory techniques, and applied clinical protocols. Lactobacillus plantarum currently represents the most studied strain, showing a positive application in burns compared to guideline treatments, and an additional mean in chronic wound infections.

CONCLUSIONS

Although preliminary evidence supports the use of specific strains of probiotics in certain clinical settings such as infected chronic wounds, large, long-term clinical trials are still lacking, and further research is needed.

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.

Antibacterial activity and characterisation of some Egyptian honey of different floral origin

The aim of the current study was to evaluate the antibacterial activity and to analyse the physicochemical properties of some Egyptian honey of different botanical origin in comparison with Manuka honey from New Zealand. Antibacterial activity of Egyptian honey of different floral origin was evaluated against five reference bacterial strains including both Gram-positive and Gram-negative bacteria using well diffusion method. Pollen analysis was used to confirm the floral origin of honey. Meanwhile, the physicochemical parameters including total phenolic and total flavonoid contents were measured to assess the quality of honey. Some honey types including Flowers, Aashab, Bardakosh, and Black seed honey showed significant antibacterial activity against Staphylococcus aureus (ATCC 25923) when compared with clindamycin. The same types of honey, except Black seed honey exhibited significant antibacterial activity against Citrobacter diversus (ATCC 13315). The total phenolic and total flavonoid contents ranged from 130.5±9.0 to 175.3±11.3 mg GAE/100 g honey and 22.3±1.7–30.9±2.6 mg RE/100 g honey, respectively. The results indicated that Egyptian honey is a promising natural product that can be potentially used as an alternative to synthetic antibiotics. Authentication of honey through the investigation of its physicochemical characteristics is a very important determinant of its biological activity. Separation and investigation of the antimicrobial activity of each of the active compounds of honey will provide more information on the efficacy and the mechanism of its biological activity. Further studies are still needed to identify and standardise protocols for the use of honey either in the protection against or the treatment of microbial infections.

Antibiofilm Activity of Heather and Manuka Honeys and Antivirulence Potential of Some of Their Constituents on the DsbA1 Enzyme of Pseudomonas aeruginosa

Heather honey was tested for its effect on the formation of biofilms by Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, Salmonella Enteriditis and Acinetobacter baumanii in comparison with Manuka honey. At 0.25 mg/mL, Heather honey inhibited biofilm formation in S. aureus, A. baumanii, E. coli, S. Enteriditis and P. aeruginosa, but promoted the growth of E. faecalis and K. pneumoniae biofilms. Manuka honey inhibited biofilm formation in K. pneumoniae, E. faecalis, and S. Enteriditis, A. baumanii, E. coli and P. aeruginosa, but promoted S. aureus biofilm formation. Molecular docking with Autodock Vina was performed to calculate the predictive binding affinities and ligand efficiencies of Manuka and Heather honey constituents for PaDsbA1, the main enzyme controlling the correct folding of virulence proteins in Pseudomonas aeruginosa. A number of constituents, including benzoic acid and methylglyoxal, present in Heather and/or Manuka honey, revealed high ligand efficiencies for the target enzyme. This helps support, to some extent, the decrease in P. aeruginosa biofilm formation observed for such honeys.

In vitro antibacterial activity of honey against multidrug-resistant Shigella sonnei

BACKGROUND AND PURPOSE

The health benefits of honey as an oral therapeutic agent for the treatment of diarrhoea caused by Shigella sonnei depend on the ability of honey to withstand human gastrointestinal conditions. This study aimed to investigate whether honey could withstand and inhibit the growth of Shigella sonnei under such conditions.

MATERIALS AND METHODS

We initially evaluated the survival of Shigella sonnei in human simulated gastric conditions (SGC) and simulated intestinal conditions (SIC). This was followed by determination of the susceptibility of Shigella sonnei to Manuka and Talah honey under gastrointestinal conditions. The colony forming units (CFU) of Shigella sonnei and minimum inhibitory concentrations (MICs) of honey were calculated.

RESULTS

Shigella sonnei was unable to survive in the acidic environment of the stomach without food matrix and survived only when inoculated with a food source, resulting in 1.5 × 10⁵ ± 0.2 CFU at 60 min and 1.7 × 10⁵ ± 0.3 CFU after 120 min of incubation. In SIC, it survived both with and without food matrix at the same CFU (1.2 × 10⁷ ±0.4) at 60 min and 1.7 × 10⁷ ±0.2 CFU after 120 min of incubation. Growth of Shigella sonnei was not observed in SGC in the presence of either honey at different concentrations without a food source. In the presence of a food source, Manuka honey inhibited the growth of Shigella sonnei at 10% v/v and Talah honey at 20% v/v dilutions in SGC. In SIC, Manuka honey inhibited the growth of Shigella sonnei at 15% and 20% v/v dilutions, whereas Talah honey inhibited Shigella sonnei at 20% and 25% v/v dilutions without and with food sources, respectively.

CONCLUSION

Shigella sonnei can survive in the acidic environment of the stomach if inoculated with a food source. Acidic pH and pepsin had no deleterious effects on the antibacterial capability of honey. However, bile reduced the antibacterial activity of honey in the intestinal environment.

Antimicrobial and mechanism of antagonistic activity of Bacillus sp. A2 against pathogenic fungus and bacteria: The implication on honey's regulatory mechanism on host's microbiota

Honey is thought to act against microbes and regulates microbiota balance, and this is mainly attributed to the enzymatic production of hydrogen peroxide, high osmolarity, and nonperoxidase factors, for example, lysozyme and botanical sources of nectar, while the effect of honey's probiotic is recently considered. The study of honey as source of beneficial microbes is understudied. The purpose of this study was to screen for the beneficial microorganisms in honey with antagonistic property against important pathogens and the mechanism of antimicrobial activity and thus play a beneficial role as probiotics. The results showed that one out of the fourteen bacterial isolates had antimicrobial activity and was identified as Bacillus Sp. A2 by 16S rRNA sequence and morphology. Antimicrobial activity of the isolate against C. albicans, E. coli, and S. aureus was confirmed by Agar well diffusion and liquid coculture assays, and the propagation of those microbes was significantly inhibited after treatment with the isolate Bacillus sp. A2 (p < .05) in comparison with untreated negative control and positive control (fluconazole, chloramphenicol, L. plantarum). The morphological changes including the distorted shape with indentations and leakages (SEM), damaged cell membrane, and cell wall with the disintegration and attachment of the Bacillus sp. A2 (TEM) in treated C. albicans were observed. Meanwhile, reactive oxygen species accumulation and decreased mitochondrial membrane potential were detected in treated C. albicans. These results revealed that the isolate Bacillus sp. A2 from honey has significant antimicrobial activity (p < .05) against C. albicans in comparison with untreated negative control and positive control L. plantarum, which depends on the accumulation of reactive oxygen species, mitochondrial damage, and the cell apoptosis. We concluded that the Bacillus sp. A2 possess the antimicrobial property, which may contribute to regulation of host's microbiota as a beneficial microbe or probiotic.

Honey and children: only a grandma's panacea or a real useful tool?

Honey is a natural product that has been used as medication since the ancient times for its nutritive and therapeutic value. Despite these properties, honey use has been limited in evidence-based medicine due to the lack of evidence in clinical settings, particularly in paediatric population. An increasing interest has grown towards honey during the last years. The aim of this article is to examine the possible role of honey as a therapeutic tool in paediatrics. We performed a literature search to summarise the highest quality evidences, analysed articles regarding honey's nutritional properties and therapeutic value. The state of the art is represented by evidences related to beneficiary effects of honey on respiratory, gastroenterological and oncohaematologic diseases. Many other uses could promisingly come from in vitro studies or clinical trial based on adult samples. Honey shows an excellent risk-benefit profile and can be safely administrated in children older than 12 months. In conclusion, honey does not only represent a grandma's remedy, but is a real useful tool in different clinical settings, including paediatrics practice. However, there is a need for high-quality, large randomised controlled trials confirming effectiveness and practical application of honey in paediatric population.

Manuka honey chelates iron and impacts iron regulation in key bacterial pathogens

AIM

The aim of this study was to test the hypothesis that Manuka honey (MH) chelates iron and promotes an iron-limiting environment, which contributes to its antimicrobial activity.

METHODS AND RESULTS

Employing a ferrozine-based assay, we observed that MH is an iron chelator that depletes iron from solution. Siderophores are small molecules that bind ferric iron (III) with high affinity and their levels are upregulated by bacteria under iron-limiting conditions. We demonstrated by quantitating siderophore production that Escherichia coli and Pseudomonas aeruginosa treated with MH sub-minimum inhibitory concentrations (sub-MIC) experience an iron-limiting environment and increase siderophore production. In addition, supplementation with ferrous iron (II) significantly increased growth of E. coli, Staphylococcus aureus and P. aeruginosa cultured at their MH MIC above that observed in nonsupplemented controls. By contrast, supplementation with ferric iron (III) significantly increased growth for only E. coli and P. aeruginosa, above their nonsupplemented controls.

CONCLUSIONS

Manuka honey chelates iron, thereby generating an iron-limiting environment for E. coli and P. aeruginosa, and to a lesser extent S. aureus, which contributes to its antimicrobial properties.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our work demonstrates that MH-induced iron chelation is an antimicrobial mechanism that differentially impacts the bacterial species tested here. Iron chelation affects multiple diverse physiological processes in bacteria and would contribute to the lack of bacterial resistance to MH. Iron metabolism is tightly regulated; bacteria require this essential nutrient for survival, but in excess it is toxic. Additional exploration of MH's iron chelation mechanism will facilitate its future use in mainstream medicine.

In vitro evaluation of methicillin-resistant and methicillin-sensitive Staphylococcus aureus susceptibility to Saudi honeys

Background

Honey has been increasingly recognized as a potential therapeutic agent for treatment of wound infections. There is an urgent need for assessment and evaluation of the antibacterial properties against wound pathogens of honeys that have not yet been tested.

Methods

Ten Saudi honeys collected from different geographical locations were screened initially for their antibacterial potential against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) by the agar well diffusion method. Manuka honey (UMF-12) was used for comparison. Of the tested honeys, the honey that exhibited the greatest antibacterial activity in the agar well diffusion assay was further evaluated for its minimum inhibitory concentration (MIC) against ten MRSA clinical isolates and three American Type Culture Collection (ATCC) reference strains by the microbroth dilution method.

Results

Locally produced honeys exhibited variable antibacterial activity against the tested isolates in the agar well diffusion assay. They were unable to exhibit antibacterial activity against MSSA and MRSA at 25% dilutions (w/v) in catalase solution. However, Sumra and Talha honeys showed a zone of inhibition at 50% dilutions (w/v) in catalase solution. This finding means that both honeys possess weak non-peroxide-based antibacterial activity. Moreover, Sumra honey showed a larger inhibition zone at 50 and 25% dilutions (w/v) in distilled water than Manuka honey against both MSSA and MRSA. This result demonstrates that Sumra honey has more hydrogen peroxide-related antibacterial activity or total antibacterial activity than Manuka honey. In addition, MIC results obtained through a microbroth dilution assay showed that Sumra honey inhibited the growth of all MRSA clinical isolates (n = 10) and reference strains [MRSA (ATCC 43300) and MSSA (ATCC 29213)] at lower concentrations (12.0% v/v) than those required for Manuka honey-mediated inhibition (14.0% v/v). This result means that Sumra honey has more peroxide or synergistic antibacterial activity than Manuka honey. An equivalent MIC (15.0% v/v) was observed for E. coli (ATCC 25922) between Manuka honey and Sumra honey.

Conclusions

Sumra honey may be used as an alternative therapeutic agent for infected wounds and burns, where additional hydrogen peroxide-related antibacterial activity is needed. In the future, the physiochemical characteristics of Sumra honey may be evaluated and standardized.

Impact of olive oil and honey on healing of diabetic foot: a randomized controlled trial

Background: This study aimed 1) to examine the impact of honey on diabetic foot; 2) to examine the effect of olive oil on diabetic foot; and 3) to compare the impact of honey and olive oil in the healing of diabetic foot.

Methods: In this randomized controlled trial, 45 patients took part. Patients were randomly assigned to three groups. In the honey group, the wound was dressed using gauzes with honey daily for 1 month. In the olive oil group, the wound was dressed using gauzes with olive oil (4 mL) daily for 1 month. Patients in the control group received usual dressing. Wounds were assessed before and after intervention using the Wagner scoring system and the checklist of diabetic foot healing (where a higher score indicates better wound healing).

Results: Demographic characteristics of patients in the three groups were similar. Mean scores of tissue around the wound, wound grade, wound drainage, and wound healing were similar before intervention in all three groups. After intervention, means score of tissue around the wound, wound grade, wound drainage, and wound healing were significantly higher in patients in the honey and olive oil groups compared to patients in the control group.

Conclusion: The results of this study reveal that honey is as effective as olive oil in the treatment of diabetic foot. Given the few studies on this topic, further investigation is needed.

Isolation of Helicobacter pylori from Gastric Biopsy of Dyspeptic Patients in Ghana and In Vitro Preliminary Assessment of the Effect of Dissotis rotundifolia Extract on Its Growth

Helicobacter pylori (H. pylori) is a gram-negative bacterium that colonizes the human stomach. Infection with this microaerophilic bacterium causes gastric and duodenal ulcer. This study sought to isolate H. pylori, from gastric biopsy samples of dyspeptic patients in Ghana using a 2,3,5-triphenyltetrazolium chloride (TTC) dye incorporated medium method. This TTC dye method was further used in an antimicrobial susceptibility assay involving Dissotis rotundifolia extract (DRE). H. pylori were successfully isolated from gastric biopsy of dyspeptic patients. Pure cultures of H. pylori in 2,3,5-triphenyltetrazolium chloride (TTC) dye incorporated medium were seen as sparkling colonies. Isolates, identified as H. pylori, were gram-negative and urease, catalase, and oxidase positive and showed characteristic morphology as spiral-shaped bacteria under the microscope. The organisms were found to be susceptible to cephalothin and resistant to nalidixic acid. Above all, the observation that H. pylori grew only at 37°C and not 25°C or 42°C affirms that the bacterium is neither Helicobacter cinaedi nor Helicobacter fenneliae. The anti-H. pylori study depicts a statistically lower zone of inhibition for DRE compared to standard drugs [amoxicillin and clarithromycin] (p<0.05), whereas metronidazole showed no zone of inhibition. This study reports the first successful isolation and culturing of H. pylori in Ghana using TTC dye. It also shows that DRE possess an in vitro anti-H. pylori activity and that DRE has some therapeutic potential against H. pylori infection.

Study of the Anti-Staphylococcal Potential of Honeys Produced in Northern Poland

The antimicrobial activity of 144 samples of honeys including 95 products from apiaries located in Northern Poland was evaluated. The antibacterial activity of those natural products, their thermal stability, and activity in the presence of catalase was investigated by microdilution assays in titration plates. The MTT assay was performed for the determination of anti-biofilm activity. Spectrophotometric assays were used for the determination of antioxidant potential, total phenolic content, and ability to generate hydrogen peroxide. Some of the investigated honeys exhibited surprisingly high antimicrobial, especially anti-staphylococcal, potential, with Minimal Inhibitory Concentration (MIC) values of only 1.56% (v/v). Much higher resistance was observed in the case of staphylococci growing as biofilms. Lower concentrations of the product, up to 12.5% (v/v) stimulated its growth and effective eradication of biofilm required concentration of at least 25% (v/v). Hydrogen peroxide has been identified as a crucial contributor to the antimicrobial activity of honeys supplied by Polish beekeepers. However, some of the results suggest that phytochemicals, especially polyphenols, play an important role depending on botanical source (both positive, e.g., in the case of buckwheat honeys as well as negative, e.g., in the case of some rapeseed honeys) in their antimicrobial potential.