Finding New Zealand honeys with outstanding antibacterial and antifungal activity.
New Zealand Beekeeper. 4(10):20-26; Nov 1997

Describes a research project carried out between Mar 1996 and Jun 1997 at the University of Waikato to determine honey antimicrobial activity and medical potential. Presents results from 179 mon-floral honey samples from 27 plant sources, excluding Manuka, when tested against four infecting organisms: Staphylococcus aureus, Escherfchie coli, Candida albicans, and the fungus Trichophyton mentagrophytes var mentagrophytes.

Honey's sources kept secret
New Zealand Beekeeper. 5(11):25; Dec 1998

Discusses the discovery that some strains of native manuka bush honey have special antibacterial properties that makes the product suitable for the export market.

The sensitivity of mastitis-causing bacteria to the antibacterial activity of honey.
Allen KL, Molan PC,
New Zealand Journal of Agricultural Research 1997 Dec;40(4):537-540 1997.

The use of honey as a wound dressing is well established in traditional and modern medicine. There are many reports of its effectiveness in clearing bacterial infections in ulcers and abscesses, which suggest that it may be suitable for the intramammary treatment of mastitis. To evaluate this possibility, the species of bacteria that commonly cause mastitis in dairy cows were tested for their sensitivity to the antibacterial activity of honey. The growth of all seven "species tested was completely inhibited by a typical honey (with antibacterial activity attributed to its content of hydrogen peroxide) at a concentration of 10% (v/v) in the agar plates, and two by 5% honey. Six of the species were completely inhibited by a typical manuka honey (with antibacterial activity attributed to its content of a non-peroxide component) at a concentration of 5% (v/v). Only one species was inhibited by 10% (v/v) artificial honey (sugars and gluconic acid as in honey). As honey is harmless to tissues and would leave no undesirable residues in milk, it would be of interest to now evaluate it therapeutically in clinical mastitis.

Susceptibility of Helicobacter pylori to the antibacterial activity of manuka honey.
Al-Somal-N; Coley-KE; Molan-PC; Hancock-BM , .
Journal-of-the-Royal-Society-of-Medicine; 87 (1) 9-12, 29 ref. 1994

Honey is a traditional remedy for dyspepsia. Sensitivity of Helicobacter pylori (a possible causative agent of dyspepsia) to honey was tested, using isolates from biopsies of gastric ulcers. All 5 isolates tested were sensitive to a 20% (v/v) solution of manuka (Leptospermum scoparium) honey in an agar well diffusion assay, but none showed sensitivity to a 40% solution of another honey in which the antibacterial activity was due primarily to its content of H2O2. Assessment of the min. inhibitory concn. by inclusion of manuka honey in agar showed that visible growth of all 7 isolates tested was prevented completely by 5% (v/v) honey over the incubation period of 72 h. Partial inhibition of some isolates occurred at 2.5% (v/v) honey. It is concluded that an antibacterial agent effective against H. pylori may be present in the pollen or an extract of the manuka tree.

Nature and origin of the antibacterial substances in honey.
Bogdanov S.
Food Science & Technology-Lebensmittel-Wissenschaft & Technologie 1997;30(7):748-753

The nonperoxide antibacterial activity of honey and honey fractions was tested with Staphylococcus aureus and Micrococcus luteus bacterial species. Antibacterial activity correlated significantly with the honey acidity but did not correlate with honey pH. There were small differences between the antibacterial activities of different honey types: rhododendron, eucalyptus and orange honeys had a relatively low activity, whereas dandelion, honeydew and rape honeys had a relatively higher activity. These results suggest that a part of the antibacterial activity might be of plant origin. However, the antibacterial activity of sugar-adulterated honeys was the same as that of control honeydew honeys produced in the same apiary suggesting that the major part of the antibacterial activity of honeydew honey is of bee origin. Ten different honeys were fractionated into four fractions wing column chromatography or vacuum distillation: acidic; basic; nonvolatile, nonpolar; and volatile. The antibacterial activity of the different fractions tested was: acids > bases = nonpolar nonvolatiles > volatiles. This order was the same using either Staph. aureus or Micrococcus luteus as test strains. An exception was manuka honey from New Zealand where almost the entire activity was found in the acidic fraction.

This is a duplicate of the reference above, the abstract is slightly different.
Nature and origin of the antibacterial substances in honey.
Bogdanov-S , .
Lebensmittel-Wissenschaft-und-Technologie; 30 (7) 748-753, 23 ref.

Antibacterial activities of different unifloral and polyfloral honeys (market samples of foreign origin or Swiss samples of known origin, including acacia, blossom, chestnut, dandelion, eucalyptus, lavender, orange, rape, rhododendron, sunflower, honeydew, manuka and mountain) and honey fractions were studied. Honey samples were fractionated using column chromatography or vacuum distillation into 4 fractions (acidic, basic, nonvolatile nonpolar, and volatile) to investigate the nonperoxidase antimicrobial activity; Staphylococcus aureus and Micrococcus luteus were used in quantitative turbidometric assays as test strains because they are known to be sensitive to honey antibacterial compounds and are widely used for testing antibacterial action. The nonperoxide antibacterial activity in honey samples was found to correlate significantly with acid content of the honey, but not with its pH. Activities differed in the unifloral honeys: rhododendron and eucalyptus honeys had the lowest activity, while honeydew and rape honeys had the highest activity. However, due to the considerable variation in antibacterial activity within honey types, the differences were not statistically significant. From experiments with sugar-adulterated honey, it was shown that the antibacterial activity of honeydew honeys was of bee origin. By fractionation into different substance classes, the following relative distribution of nonperoxide antibacterial activity was found: acids greater than bases = n

Therapeutic properties of New Zealand and Australian tea trees (Leptospermum and Melaleuca)
Carr,-Anitra-C (Canterbury College of Natural Medicine)
New Zealand Pharmacy. 18(2):29-31; Feb 1998

Confirms the antimicrobial activity of tea tree oil against several common bacterial and fungal pathogens. Describes the therapeutic properties of manuka honey used as an antibacterial and looks at the future prospects of manuka oil as an antimicrobial.

Antibacterial activity of honey against strains of Staphylococcus aureus from infected wounds
Cooper RA, Molan PC, Harding KG
Journal of the Royal Society of Medicine 1999 Jun;92(6):283-285

The antibacterial action of honey in infected wounds does not depend wholly on its high osmolarity. We tested the sensitivity of 58 strains of coagulase-positive Staphylococcus aureus, isolated from infected wounds, to a pasture honey and a manuka honey. There was little variation between the isolates in their sensitivity to honey: minimum inhibitory concentrations were all between 2 and 3% (v/v) for the manuka honey and between 3 and 4% for the pasture honey. Thus, these honeys would prevent growth of S. aureus if diluted by body fluids a further seven-fold to fourteen-fold beyond the point where their osmolarity ceased to be completely inhibitory. The antibacterial action of the pasture honey relied on release of hydrogen peroxide, which in vivo might be reduced by catalase activity in tissues or blood. The action of manuka honey stems partly from a phytochemical component, so this type of honey might be more effective in vivo. Comparative clinical trials with standardized honeys are needed.

Why honey is effective as a medicine - 2. The scientific explanation of its effects [Review]
Molan PRA - Molan P
Bee World. 82(1):22-40, 2001.AS - Bee World 2001;82(1):22-40PU - INT BEE RESEARCH ASSOC, JOURNALS LIBRARIAN, 18 NORTH RD, CARDIFF CF1 3DY, WALES. URL:

The effectiveness of honey as a therapeutic agent has been unequivocally demonstrated in the literature reviewed in Part 1 of this article published in 1999, but the biochemical explanation of these effects is more hypothetical, However a rational explanation can be seen when one looks at the scientific literature outside that on honey, Some of the components of honey are substances known to have physiological actions that would explain many of its therapeutic effects. in addition, research on honey has shown directly that it has physiological actions that would give therapeutic effects.

Non-peroxide antibacterial activity in some New Zealand honeys.
Molan-PC; Russell-KM
Journal-of-Apicultural-Research; 27 (1) 62-67, 15 ref.

A range of New Zealand monofloral honeys was assayed for antibacterial activity with and without the presence of hydrogen peroxide (inactivated by the addition of catalase). In honeys with high antibacterial activity a large part of this activity was due to a factor other than hydrogen peroxide. The test microorganism used, Staphylococcus aureus, was not inhibited by the osmolarity or the acidity of the honey. The association of high antibacterial activity with particular floral sources suggests that the non-peroxide antibacterial activity may be of floral origin. The antibacterial activity of manuka honey was tested and found to be heat-stable.

Non-peroxide antibacterial activity in some New Zealand honeys.
Molan-PC; Russell-KM
Journal-of-Apicultural-Research. 1988, 27: 1, 62-67; Bb.

A range of New Zealand unifloral honeys was assayed for antibacterial activity with and without the hydrogen peroxide present (inactivated by the addition of catalase). It was found that in the honeys with high antibacterial activity a large part of this activity was due to a factor other than hydrogen peroxide. The test microorganism used, Staphylococcus aureus, was not inhibited by the osmolarity or the acidity of the honey. The association of high antibacterial activity with particular floral sources suggests that the non-peroxide antibacterial activity is of floral origin. The activity of manuka honey was tested and found to be heat-stable.

There is increasing usage of honey as a dressing on infected wounds, burns and ulcers, but there is some concern that there may be a risk of wound botulism from the clostridial spores sometimes found in honey. Therefore an investigation was carried out to assess the effect on the antibacterial activity of honey of a commercial sterilization procedure using gamma-irradiation (25 kGy). Two honeys with antibacterial activity due to enzymically-generated hydrogen peroxide and three manuka honeys with non-peroxide antibacterial activity were investigated. The honeys were tested against Staphylococcus aureus in an agar well diffusion assay. There was no significant change found in either type of antibacterial activity resulting from this form of sterilization of honey, even when the radiation was doubled to 50 kGy. Testing of honey seeded with spores of Clostridium perfringens and C. tetani (10 000 and 1000 spores/g honey, respectively) showed that 25 kGy of gamma-irradiation was sufficient to achieve sterility.

Sixty-four samples of monofloral honeys were diluted to -1/4, -1/ 8 or -1/16 original strength and tested in an agar well diffusion assay against Staphylococcus aureus. Antibacterial activity was calculated in terms of mean weighted sum of inhibitory zones. Significant differences in activity were found between different kinds of honey (P less than 0.0001). The more active honeys were kanuka, manuka and penny royal, followed by nodding thistle, kamahi and buttercup. Honeys with lowest activity were rewa-rewa, clover, heather, tawari, rata, towai, thyme and blue borage. Pollen analysis of honey was not carried out, which may account for some inconsistencies in results due to inaccurate identification of honeys.

Healing of an MRSA-colonized, hydroxyurea-induced leg ulcer with honey
Natarajan S, Williamson D, Grey J, Harding KG, Cooper RAMA - subramanian_natarajan@hotmail.comRA - Natarajan S,
Journal of Dermatological Treatment. 12(1):33-36, 2001 Mar.AS - J. Dermatol. Treat 2001 Mar;12(1):33-36PU - MARTIN DUNITZ LTD, LIVERY HOUSE, 7-9 PRATT

BACKGROUND: With the everincreasing emergence of antibiotic-resistant pathogens, in particular methicillin-resistant Staphylococcus aureus (MRSA) in leg ulcers, a means of reducing the bacterial bioburden of such ulcers, other than by the use of either topical or systemic antibiotics, is urgently required. METHODS: We report the case of an immunosuppressed patient who developed a hydroxyurea-induced leg ulcer with subclinical MRSA infection which was subsequently treated with topical application of manuka honey, without cessation of hydroxyurea or cyclosporin, RESULTS: MRSA was eradicated from the ulcer and rapid healing was successfully achieved. CONCLUSION: Honey is recognized to have antibacterial properties, and can also promote effective wound healing. A traditional therapy, therefore, appears to have enormous potential in solving new problems.

Osmotic effect of honey on growth and viability of Helicobacter pylori
Osato MS, Reddy SG, Graham DY
Digestive Diseases & Sciences 1999 Mar;44(3):462-464

Honey from New Zealand and Saudi Arabia at concentrations approximating 20% (v/v) inhibit the growth of H. pylori in vitro. The anti-H. pylori effect involves both hydrogen peroxide- and non-peroxide-mediated killing mechanisms. This study was designed to determine whether the anti-H. pylori activity of honey differed regionally (honey from Texas, Iowa, and New Zealand) and to determine whether this activity was due to the presence of hydrogen peroxide. Broth dilution susceptibility tests were performed using solutions of honey prepared in BHI broth ranging in concentration from 5 to 35% (v/v) in 5% increments. Control solutions containing glucose, fructose, and combined glucose/fructose solutions in ratios of 1:1.23 were also prepared. Paired catalase controls were included in all tests. Twenty-eight clinical isolates of H, pylori were tested. Growth was determined on the basis of a plus/minus grading score. All of the solutions containing either fructose, glucose, glucose and fructose combinations, or honey were equally effective in inhibiting the growth of H. pylori. Ail of the isolates were inhibited by solutions containing 15% (w/v) carbohydrate. Honey solutions, with or without catalase, inhibited 24/28 isolates at a concentration of 10%, and 28/28 isolates at a concentration of 15%. In conclusion, regional differences in honey activity against H. pylori were not detected, nor was the effect of killing related to the presence of hydrogen peroxide in the honey samples.

Manuka honey for central vein catheter exit site care
Quadri KHM, Huraib SO
Seminars in Dialysis 1999 Sep-Oct;12(5):397-398

The antibacterial properties of honey.
Russell-KM
1983, 150 pp. PB: University of Waikato, Hamilton; New Zealand

An agar diffusion technique incorporating Staphylococcus aureus was used to detect antibiotic activity in various honeys. Manuka [Leptospermum scoparium] honey exhibited the greatest antibacterial activity and was selected for further investigation. The activity was completely heat-stable ( at 95°C for 1 h) at acidic pH, but less stable at neutral pH, and the honey had less antibacterial activity at neutral pH. Solvent extraction of the honey was carried out with ethanol, and ether was added to precipitate most of the sugars. All antibacterial activity was isolated in the extract, and further isolation of the active fractions was carried out using preparative TLC. The fractions were then analysed by UV spectroscopy, IR spectroscopy, NMR and mass spectrometry. The compounds identified in the active fractions were methyl 3,4,5-trimethoxybenzoate, methyl 4-hydroxy-3,5-dimethoxybenzoate and 3,4,5-trimethoxybenzoic acid.Author.

Identification of some antibacterial constituents of New Zealand manuka honey.
Russell-KM; Molan-PC; Wilkins-AL; Holland-PT
Journal-of-Agricultural-and-Food-Chemistry; 38 (1) 10-13, 21 ref.

Some components responsible for the exceptionally high antibacterial activity of manuka honey were isolated by testing fractions of the honey for activity against Staphylococcus aureus. An ethanol-ether extract of the honey was separated by preparative-layer chromatography and the fractions thus obtained were assessed for antibacterial activity. One fairly homogeneous fraction was identified as methyl 3,5-dimethoxy-4-hydroxybenzoate (methyl syringate). Combined GC-MS indicated the presence of this compound in some of the other antibacterial fractions together with methyl 3,4,5-trimethoxybenzoate and 3,4,5-trimethoxybenzoic acid. Authentic specimens of 3,5-dimethoxy-4-hydroxybenzoic acid ( syringic acid) and 3,4,5-trimethoxybenzoic acid and their methyl esters were tested against S. aureus. The acids and, to a lesser extent, methyl syringate were found to possess significant antibacterial activity.

Stimulation of TNF-alpha release in monocytes by honey
Tonks A, Cooper RA, Price AJ, Molan PC, Jones KPMA - kpjones@uwic.ac.ukRA - Jones KP
Cytokine. 14(4):240-242, 2001 May 21.AS - Cytokine 2001 May 21;14(4):240-242PU - W B SAUNDERS CO, INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHI

Although evidence exists for the antibacterial effects of honey there is limited objective evidence for direct promotion of healing, We investigated the effect of manuka, pasture and an artificial honey on macrophage function. Reactive oxygen intermediate (ROI) production was assessed by luminol enhanced chemoluminescence and tumour necrosis factor-alpha (TNF-1 alpha) release was determined by immunoassay, ROI production was significantly (P<0.001) decreased by pasture honey and manuka honey. TNF-<alpha> release was significantly enhanced (P<0.001) in unprimed MM6 cells by manuka and pasture honey but was not altered in primed cells. These results could explain the suggested therapeutic properties of honey in promoting wound healing.

The oligosaccharide composition of some New Zealand honeys
Weston RJ, Brocklebank LK
Food Chemistry 1999 Jan;64(1):33-37

The oligosaccharide fraction of samples of manuka (Leptospermum), heather (Calluna), clover (Trifolium) and beech honeydew (Nothofagus) honeys from New Zealand was separated from the monosaccharides and then analysed by high performance anion-exchange chromatography with pulsed amperometric detection (hpaec-pad). In vitro non-peroxide antibacterial activity against Staphylococcus aureus was assessed by well diffusion assay. Antibacterial activity had no effect on oligosaccharide profiles of manuka honeys. Significant oligosaccharide components of manuka honey were isomaltose (or maltulose), kojibiose, turanose (or gentiobiose), nigerose and maltose which was the major component. The composition of clover honey was identical to that of manuka, while heather honey differed from these two only because isomaltose was the major component. Beech honeydew honey was characterised by the complexity of the oligosaccharide composition. The trisaccharides melezitose and panose were the most abundant components. No differences were observed between the oligosaccharide compositions of manuka honeys which did or did not exhibit non-peroxide residual antibacterial activity. Manuka honey was shown to be derived from nectar and not honeydew as has been suggested.

The contribution of catalase and other natural products to the antibacterial activity of honey: a review.
Weston-RJ
Food-Chemistry; 71 (2000) 235-239, 51 ref.NU: 0308-8146DT: Review

Contributions of catalase and other components to the antibacterial activity of honeys are discussed with reference to the potential antibacterial activity of: beeswax; volatile compounds in honey extracts; nectar; pollen; propolis; honey phenols; and manuka honey. It is suggested that the non-peroxide antibacterial activity observed in manuka honey, is not due to a unique manuka product, but due to an accumulation of hydrogen peroxide in the absence of a plant-derived catalase.

Identification and quantitative levels of antibacterial components of some New Zealand honeys.
Weston-RJ; Brocklebank-LK; Yinrong-Lu
Food-Chemistry; 70 (2000) 427-435, 32 ref.NU: 0308-8146DT: Journal-Article

In order to identify components in honey that are responsible for non-peroxide antibacterial activity (NPABA) of certain honeys, HPLC profiles of phenolic fractions from 19 samples of New Zealand manuka honey with varying levels of NPABA were determined. HPLC profiles of manuka honey were compared with those obtained for heather, clover and beech honeydew honeys. HPLC profiles of phenols from manuka honey demonstrated that phenols are not responsible for NPABA, as honeys with high levels of NPABA had identical profiles to those with low NPABA. Other agents were investigated that may have been responsible for NPABA; antibacterial insect peptides, including lysozyme and royalisin, and leptospermone, a beta-triketone, however they were not detected in manuka honey with NPABA. Levels of phenols in manuka honey were comparable to data published for European honeys. Methyl syringate comprised approx. 70% (w/w) of phenols in the phenol fraction and may be suitable for use as a floral marker for manuka honey. HPLC profiles of manuka, clover, beech honeydew and heather honeys were distinguishable. It is suggested that use of HPLC profiles has potential for differentiating between honey types.

Antibacterial phenolic components of New Zealand manuka honey.
Weston-RJ; Mitchell-KR; Allen-KL
Food-Chemistry; 64 (1999) 295-301, 30 ref.

Antibacterial phenolic fractions (APF) were isolated from manuka honey by a number of chromatographic methods (HPLC, chromatography on poly(capryl)amide, Sephadex G-10, XAD-2 resin, Biogel P-2, TLC, etc.) and were investigated for their contributions to antibacterial activity of the honey. APF comprised phenolic derivatives of benzoic acids, cinnamic acids and flavonoids. Active phenolic extracts contained methyl syringate at greater than 45% with phenyllactic acid as an additional major component. To determine whether these components contributed significantly to non-peroxide antibacterial activity, a range of honey extracts was adsorbed onto paper discs and examined by bioassay. Neither methyl syringate nor phenyllactic acid showed antibacterial activity, while levels of flavonoid components were too low to contribute significantly to antibacterial activity. Results suggest that APF were only partially responsible for non-peroxide antibacterial activity in manuka honeys. Since component monosaccharides showed no antibacterial activity, data indicate that an antibacterial substance is being `carried' by the monosaccharides which form the bulk of the honey.

Honey: nectar or a nutraceutical?
Woollen-A
Food-Processing,-UK; 63 (11) 12

Antibiotic activity of manuka honey, produced from manuka bushes growing in large areas of wild scrubland in New Zealand, is discussed. Use of the honey to treat Helicobacter gastric infections is currently being studied.

Honey, a prospective antibiotic: extraction, formulation, and stabilit
Zaghloul AA, El-Shattawy HH, Kassem AA, Ibrahim EA, Reddy IK, Khan MAMA - abdel@cortex.ama.ttuhsc.eduRA - Zaghloul AA
Pharmazie. 56(8):643-647, 2001 Aug.AS - Pharmazie 2001 Aug;56(8):643-647PU - GOVI-VERLAG GMBH, PHARMAZEUTISCHER VERLAG GINNHEIMER STRASSE 26, D-65760

Old and recent reports show that honey has beneficial effects on the skin as antiseptic for wounds, bums and ulcers and as a healing promoter. Many investigators confirmed the usefulness of honey in the treatment of skin infections as well as internal diseases. The factors behind these effects are not completely explained. The aim of this study is: a) to investigate the antimicrobial activity of crude honey, b) to separate the fractions responsible for its activity, c) to formulate the honey extract as semisolid dosage forms, d) to study its release, and e) to determine its stability. The results showed that the ethylacetate honey extract showed antibacterial, anticandida and antifungal effects at low concentration. The release of honey extract from different ointment bases was depending on the constituents of the base, and its stability was found to be temperature and base dependent.

Manuka honey against Helicobacter pylori.
McGovern-DPB; Abbas-SZ; Vivian-G; Dalton-HR
Journal-of-the-Royal-Society-of-Medicine. 1999, 92: 8, 439; 1 ref.

Twelve non-diabetic patients with positive CLO tests but normal gastroscopies were studied. Active H. pylori infection was confirmed with 14C urea breath tests. Six patients were treated with a tablespoon of manuka honey 4 times a day for 2 weeks and 6 were treated with honey and omeprazole 20 mg twice a day for the same period. the batch of manuka honey used possessed non-peroxide antibacterial activity equivalent to 11.7% phenol. All 12 patients remained positive for 14C urea breath tests. It is concluded that manuka honey is ineffective at eradicating H. pylori.