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Honey
Research
Please
note:
All the following
articles appearing in this section are reproduced from the web
site of the Honey Research Unit at Waikato University, New Zealand
with the kind permission of Professsor Peter Molan,
director of research.
While Peter Molan
supports the use of Active Manuka Honey in wound care, his position
regarding any company, brand or honey product is totally
impartial. These articles appear here for general interest only
and are not intended to constitute medical advice or make medical
claims.
Professsor Peter Molan has no involvement with
the business activities of the Medicinal Honey Company
or its website.
This collection of
published academic articles provides an informative source of
literature regarding the use of Active Manuka Honey and will be of
interest to the public and medical professionals alike.
History
About 45 years ago research into the
healing mechanisms of honey recognised that there were marked
differences in the antibacterial activity of various types
of honey and in their ability to inhibit the growth of
micro-organisms.
Honey - an
ancient remedy "rediscovered"
P.C. Molan - Manuka Honey as a
Medicine
Paper presented at Global Bioactives Summit
,Hamilton NZ July 2001
For centurys honey has been used as a
food and a prized as a medicine, by many cultures around the world.
The usage of honey as a medicine is referred to in the most ancient
written records, it being prescribed by the physicians of many
ancient races of people for a wide variety of ailments (Ransome
1937).
It has continued to be used in folk medicine ever
since, but in recent times there has been a renaissance of the use
of honey in the medical profession: an editorial in the Journal of
the Royal Society of Medicine (Zumla and Lulat 1989 ) discussing
this expressed the opinion
"The therapeutic potential of
uncontaminated, pure honey is grossly underutilized. It is widely
available in most communities and although the mechanism of action
of several of it's properties remains obscure and needs further
investigation, the time has now come for conventional medicine to
lift the blinds off this 'traditional remedy' and give it its due
recognition."
Now it can be
seen that the effectiveness of honey in many of its medical uses is
probably due to its antibacterial activity. It is well established
that honey inhibits a broad spectrum of bacterial species. There are
many reports of bactericidal as well as bacteriostatic activity.
There have also been reports of honey having antifungal
activity.
Professor Peter Molan and
researchers at the Honey Reseach Unit at Waikato University in
New Zealand have investigated the potential and
therapeutic benefits of various honeys with special attention
focused on the ability of some Manuka Honeys to inhibit the
growth of a wide range of bacteria and
fungi.
Research in this area has identified that some
Manuka honeys have exceptionally high levels of antimicrobial
activity.This is due to both hydrogen peroxide releasing
enzymes and a unique phytochemical activity which has been
termed the Unique Manuka Factor.
The establishment by research that there are bioactive
components in honey, and the wide dissemination of this knowledge,
has led to a general acceptance that honey is a respectable
therapeutic agent, and to a rapidly increasing uptake of its usage
by clinicians as well as by the general public.
The finding
that there are multiple bioactive components involved in the
therapeutic action makes it a much more attractive option to use the
natural product rather than to attempt to identify individual active
components and use synthesised copies of those.
Selection of honey
for use on wounds
By Peter Molan,
PhD
Director of the Honey Research Unit, Department of
Biological Sciences, University of Waikato, New
Zealand
Honey is one of the
oldest known medicines that has continued to be used up to present
times in folk-medicine. Its use has been "rediscovered" in later
times by the medical profession, especially for dressing wounds. The
numerous reports of the effectiveness of honey in wound management,
including reports of several randomised controlled trials, have
recently been reviewed, rapid clearance of infection from the
treated wounds being a commonly recorded observation.
In almost all of these reports honey is
referred to generically, there being no indication given of any
awareness of the variability that generally is found in natural
products. Yet the ancient physicians were aware of differences in
the therapeutic value of the honeys available to them: Aristotle
(384-322 BC), discussing differences in honeys, referred to pale
honey being "good as a salve for sore eyes and wounds"; and
Dioscorides (c.50 AD) stated that a pale yellow honey from Attica
was the best, being "good for all rotten and hollow
ulcers".
Any honey can be expected to suppress
infection in wounds because of its high sugar content, but dressings
of sugar on a wound have to be changed more frequently than honey
dressings do to maintain a concentration of sugar that is inhibitory
to bacteria, as honey has additional antibacterial components. Since
microbiological studies have shown more than one hundred-fold
differences in the potency of the antibacterial activity of various
honey, best results would be expected if a honey with a high level
of antibacterial activity were used in the management of infected
wounds.
Other therapeutic properties of honey
besides its antibacterial activity are also likely to vary. An
anti-inflammatory action and a stimulatory effect on growth of new
blood capillaries and on the growth of granulation tissue and
epithelial cells have been observed clinically and in histological
studies. The components responsible for these effects have not been
identified, but the anti-inflammatory action may be due to
antioxidants, the level of which varies in honey. The stimulation of
tissue growth may be due to the supply of nutrients by honey, as
nutrification of wounds is known to hasten the healing process: the
level of the wide range of micronutrients that occur in honey also
varies.
Until research is carried out to
ascertain the components of honey responsible for all of its
therapeutic effects it will not be possible to fully standardise
honey to obtain optimal effectiveness in wound management. However,
where an antiseptic wound dressing is required then standardisation
for this effect is possible. Several brands of honey with
standardised levels of antibacterial activity are commercially
available in Australia and New Zealand, but even where these are not
available it is possible to assay the level of antibacterial
activity of locally available honey by a simple procedure in a
microbiology laboratory.
The antibacterial activity of honey is
due primarily to hydrogen peroxide generated by the action of an
enzyme that the bees add to the nectar, but there are some floral
sources that provide additional antibacterial components. The body
tissues and serum contain an enzyme, catalase, that breaks down
hydrogen peroxide - how much of the honey antibacterial activity is
lost through this is not known. The antibacterial components that
come from the nectar are not broken down by this enzyme. Until
comparative clinical trials are carried out to determine which type
of antibacterial activity is the more effective, it may be best to
use manuka honey, as this contains hydrogen peroxide activity as
well as the component that comes from the nectar.
Because the enzyme in honey that
produces hydrogen peroxide is destroyed by heating and exposure to
light, unpasteurised honey should be used, and it should be stored
in a cool place and protected from light. If it is necessary to warm
honey to liquefy it, it should be heated to no more than 37°C. If it
is considered necessary to sterilise honey, this can be done by
gamma-irradiation without loss of antibacterial activity.
Gamma-irradiated manuka honey is available commercially. (In none of
the clinical reports of use of honey on wounds was the honey used
sterilised. No case of infection resulting from the use of honey has
been reported.)
The way honey is used as a wound
dressing
(practical
information)
By Peter Molan,
PhD
Director of the Honey Research Unit, Department of
Biological Sciences, University of Waikato, New Zealand
Note: The information
provided in this web-site does not constitute medical advice. It is
important that wounds that are not healing are seen by a registered
medical practitioner - failure to heal may be the result of
malignancy (cancer) or defective blood circulation. Varicose leg
ulcers usually require professionally applied pressure bandaging
over the dressing to heal successfully.
- The following points have come from
clinical experience of many people using honey as a wound
dressing:
- The amount of honey required on the
wound depends on the amount of fluid exuding from the wound. The
various beneficial effects of honey on wound tissues will be
reduced or lost if small amounts of honey become diluted by large
amounts of fluid. Likewise the frequency of dressing changes
required will depend on how rapidly the honey is being diluted by
fluid.
- Daily dressing changes are usual, but up to three times daily
may be needed.
- If the dressing sticks to the wound this indicates that more
frequent changes of dressing are needed.
- Exudation of fluid should be reduced by the anti-inflammatory
action of honey, so less frequent dressing changes may be needed
later - a few days between changes.
- More honey is required on deeper infections, to obtain an
effective level of antibacterial activity diffusing deep into the
wound tissues.
- Typically, 20 ml of honey (25 - 30 g, 1 ounce) is used on a 10
cm X 10 cm (4 inch X 4 inch) dressing.
- Occlusive (waterproof) or absorbent secondary dressings are
needed to prevent honey oozing out from the wound dressing.
(Occlusive dressings are better as they keep more of the honey in
contact with the wound - absorbent dressings soak the honey away
from the wound.) Adhesive tape or bandages can be used to hold the
dressings in place if an adhesive occlusive dressing is not used.
- Pressure bandaging is used over the honey dressing for
varicose ulcers.
- Dressing pads pre-impregnated with honey are the most
convenient way of applying honey to surface wounds. (Dressing pads
pre-impregnated with active manuka honey are available
commercially).
- If pre-impregnated dressings are not available, it is best to
spread the honey on the dressing rather than on the wound.
- Abscesses, cavities and depressions in the wound bed are
filled with honey before applying the honey dressing pad, so that
there is honey in contact with the wound bed. The honey dressings
are cut to a size that extends beyond the edges of the wound and
any surrounding inflamed area.
What's special about
active manuka honey
By Peter Molan,
PhD
Director of the Honey Research Unit, Department of
Biological Sciences, University of Waikato, New Zealand
- "Active manuka honey" is the only
honey available for sale that is tested for its antibacterial
activity. It contains an additional antibacterial component found
only in honey produced from Leptospermum plants: what has been
called the "Unique Manuka Factor"
There is evidence that
the two antibacterial components (hydrogen peroxide and the
"Unique Manuka Factor") may have a synergistic action.
- Unique Manuka Factor" is not
affected by the catalase enzyme present in body tissue and serum.
This enzyme will break down, to some degree, the hydrogen peroxide
which is the major antibacterial factor found in other types of
honey. If a honey without Unique Manuka Factor"were used to treat
an infection, the potency of the honey's antibacterial activity
would most likely be reduced because of the action of
catalase.
- The enzyme that produces hydrogen
peroxide in honey is destroyed when honey is exposed to heat and
light. But Unique Manuka Factor" is stable, so there is no concern
about manuka honey losing its activity in storage.
- The enzyme that produces hydrogen
peroxide in honey becomes active only when honey is diluted. But
Unique Manuka Factor" is active in full strength honey, which will
provide a more potent antibacterial action diffusing into the
depth of infected tissues.
- The enzyme that produces hydrogen
peroxide in honey needs oxygen to be available for the reaction,
so may not work under wound dressings or in wound cavities. Honey
with Unique Manuka Factor"is active in all situations.
- The enzyme that produces hydrogen
peroxide in honey becomes active only when the acidity of honey is
neutralised by body fluids, but then the honey is diluted.
- The enzyme that produces hydrogen
peroxide in honey could be destroyed by the protein-digesting
enzymes that are in wound fluids.
- The Unique Manuka Factor
antibacterial activity diffuses deeper into skin tissues than does
the hydrogen peroxide from other types of honey.
- Honey with Unique Manuka Factor is
more effective than that with hydrogen peroxide against some types
of bacteria. For example, active manuka honey with Unique Manuka
Factoris about twice as effective as other honey against
Eschericihia coli and Staphylococcus aureus, the most common
causes of infected wounds.
Many medical professionals are using
active manuka honey and getting good results in patients with wounds
that have not responded to standard treatment. For example, a
successful trial of active manuka honey on unresponsive skin ulcers
was recently published in the New Zealand Medical Journal. In
addition, staff at a large hospital in Brisbane, Australia, recently
used active manuka honey as a wound dressing on a patient for whom
honey without Unique Manuka Factor had failed. In other hospitals
clinicians have likewise noted improvement in healing rates when
changing from other honey to a manuka honey with a good level of
Unique Manuka Factor.
None of the results being obtained
clinically should be considered evidence that active manuka honey is
more effective than other honey - a comparative clinical trial will
be needed to establish that. Nevertheless, there are good
theoretical reasons for choosing to use active manuka honey with a
good level of Unique Manuka Factor for management of wound
infections.
To rate the potency of antibacterial
activity of honey, Proff. P.C. Molan devised the testing method
and the Unique Manuka Factor number. The Unique Manuka Factor
numbers come from a standard laboratory test of antibacterial
activity, with honey being compared with a standard antiseptic
(phenol, also known as carbolic) for potency. For example, a honey
with a Unique Manuka Factor rating of 4 would be equivalent to the
antiseptic potency of 4% solution of phenol, as used as carbolic
disinfectant; a honey with a rating of 10 would have a potency
equivalent to a 10% solution of phenol.
Medical professionals in New Zealand
use active manuka honey with a rating of Unique Manuka Factor10 or
higher. Although good results may be obtained with lower levels of
activity, there is a chance that the lower activity will not be
enough to fully clear an infection. In addition, honey with a lower
level of activity will not allow as much of the antibacterial
elements to diffuse into infected tissue, which could mean that
effective control of infection may not be achieved in deeper
tissue.
To alleviate any concern over the
possible risk of introducing infection by the use of an unprocessed
natural product on wounds, honey can be sterilised by gamma
irradiation without loss of any of its antibacterial activity.
Active manuka honey and the Australian Leptospermum honey are
commercially available sterilised in this way.
The Unique Properties
of Manuka Honey
By Peter Molan,
PhD
Associate Professor of Biochemistry and Director of
the Honey Research Unit University of Waikato, Hamilton, New Zealand
For over 10 years, I have
scientifically investigated what many local New Zealanders have
accepted as common wisdom: our local manuka honey is a superior
treatment for wounds and infections. Manuka honey is gathered in New
Zealand from the manuka bush, Leptospermum scoparium, which grows
uncultivated throughout the country. (More recently, as a result of
systematic screening of Australian honeys, a honey with the same
properties has been found to be produced from Leptospermum
polygalifolium, which grows uncultivated in a few parts of
Australlia.)
After the results of my work became
known through scientific journals, many people contacted me to find
out what is so special about active manuka honey. A thorough and
scientific response is available in articles listed on my Web site,
www.honey.bio.waikato.ac.nz.
However, I have compiled the pertinent facts
here:
- Approximately 50 reports in medical
journals detail the effectiveness of honey as a wound dressing and
as therapy for eye infections and diarrhea 1, 3.
- Honey has an antibacterial activity,
due primarily to hydrogen peroxide formed in a "slow-release"
manner by the enzyme glucose oxidase present in honey, which can
vary widely in potency. Some honeys are no more antibacterial than
sugar, while others can be diluted more than 100-fold and still
halt the growth of bacteria. The difference in potency of
antibacterial activity found among the different honeys is more
than 100-fold.
- "Active manuka honey" (and its Australian equivalent) is the
only honey available for sale that is tested for its antibacterial
activity. It contains an additional antibacterial component found
only in honey produced from Leptospermum plants: "unique manuka
factor" (UMF). There is evidence that the 2 antibacterial
components may have a synergistic action.
- Unique manuka factor is not affected by the catalase enzyme
present in body tissue and serum. This enzyme will break down, to
some degree, the hydrogen peroxide which is the major
antibacterial factor found in other types of honey. If a honey
without UMF were used to treat an infection, the potency of the
honey's antibacterial activity would most likely be reduced
because of the action of catalase.
- The enzyme that produces hydrogen peroxide in honey is
destroyed when honey is exposed to heat and light. However, UMF is
stable, so there is no concern about manuka honey losing its
activity in storage.
- Honey with UMF is more effective than that with hydrogen
peroxide against some types of bacteria. For example, active mauka
honey with UMF is about twice as effective as other honey against
Eschericihia coli and Staphylococcus aureus4, 5, the most common
causes of infected wounds.
Many medical professionals are
using active mauka honey-and getting good results-in patients with
wounds that have not responded to standard treatment. For example, a
successful trial of active manuka honey on unresponsive skin ulcers
was recently published in the New Zealand Medical Journal 6. In
addition, staff at a large hospital in Brisbane, Australia, recently
used active mauka honey as a wound dressing on a patient for whom
honey without UMF had failed.
None of the results being obtained
clinically should be considered evidence that active manuka honey is
more effective than other honey-a comparative clinical trial will be
needed to establish that. Nevertheless, when asked, I recommend
active mauka honey with a good level of antibacterial activity for
management of infections.
Medical professionals in New Zealand
use active mauka honey with a rating of 10 UMF or higher. Although
good results may be obtained with lower levels of activity, there is
a chance that the lower activity will not be enough to fully clear
an infection. In addition, honey with a lower level of activity will
not allow as much of the antibacterial elements to diffuse into
infected tissue, which could mean that effective control of
infection may not be achieved in deeper tissue.
To rate the potency of antibacterial
activity of honey, I devised the testing method and the UMF number.
The UMF numbers come from a standard laboratory test of
antibacterial activity, with honey being compared with a standard
antiseptic (phenol) for potency. For example, a honey with a UMF
rating of 4 would be equivalent to the antiseptic potency of 4%
solution of phenol, a carbolic disinfectant; a honey with a rating
of 10 would have a potency equivalent to a 10% solution of phenol.
To alleviate any concern over the possible risk of introducing
infection by the use of an unprocessed natural product on wounds,
honey can be sterilised by gamma irradiation without loss of any of
its antibacterial activity.
For information on the use of honey in
managing wounds, burns, skin ulcers and necrotising fasciitis, read
the article: "The role of honey in the management of
wounds".
References
1. Molan PC. A brief review of honey as a
clinical dressing. Primary Intention 1998; 6(4): 148-58.
2. Molan PC. The role of honey in the management of wounds.
J Wound Care 1999; 8(8): 423-6.
3. Molan PC. Why honey is
effective as a medicine. 1. Its use in modern medicine. Bee World
1999; 80(2): 80-92.
4. Willix DJ, Molan PC, Harfoot CJ. A
comparison of the sensitivity of wound-infecting species of bacteria
to the antibacterial activity of manuka honey and other honey. J
Appl Bacteriol 1992; 73: 388-94.
5. Cooper RA, Molan PC,
Harding KG. Antibacterial activity of honey against strains of
Staphylococcus aureus from infected wounds. J R Soc Med 1999; 92:
283-5.
6. Wood B, Rademaker M, Molan PC. Manuka honey, a
low cost leg ulcer dressing. N Z Med J 1997; 110: 107.
7. Molan PC, Allen KL. The effect of gamma-irradiation on
the antibacterial activity of honey. J Pharm Pharmacol 1996; 48:
1206-9.
Establishing Honey as
a Recognised Medicine
By Peter Molan,
PhD
Director of the Honey Research Unit, Department of
Biological Sciences, University of Waikato, New
Zealand
Honey is becoming
accepted as a reputable and effective therapeutic agent by
practitioners of conventional medicine, and by the general public.
This has been a consequence of there being an increasing awareness
of the good clinical results that are obtained, and of there being
rational explanations for its therapeutic actions. Further
establishing this recognition of honey as a medicine involves a
combination of literature research and laboratory research to obtain
evidence and explanations of the therapeutic effectiveness of honey,
and educating medical practitioners and the general public about the
results of this research. Increasingly the medical profession is
requiring evidence-based decisions on therapeutic
options.
There are many reports in the medical
literature of honey being very effective as a dressing for wounds,
burns and skin ulcers: inflammation, swelling and pain are quickly
reduced, malodour is reduced, shedding of dead tissue is induced so
surgical removal is unnecessary, healing occurs rapidly with minimal
scarring and with no need for skin grafting, and infection is
rapidly cleared. A moist environment is created which promotes the
growth of new skin tissue. Although a moist environment also favours
the growth of infecting bacteria, the antimicrobial properties of
honey prevent infection. But unlike other antiseptics, honey is not
harmful to tissues, and actually speeds up the growth of new tissue
to heal the wound.
Most practitioners have not been aware
that there is a marked variation in the potency of the antimicrobial
activity of honey, due mainly to differences in the amount of
hydrogen peroxide generated, but sometimes to additional
antimicrobial components from specific plant sources. Honey from
manuka (Leptospermum scoparium) has an exceptionally high level of
plant-derived antibacterial activity. The most common
wound-infecting species of bacteria, Staphylococcus aureus, has been
found to be particularly sensitive to this. All of the common
wound-infecting species of bacteria have been tested and found to be
sensitive to both types of antibacterial activity in honey. Clearing
bacterial infection from a wound is essential to allow the healing
process to occur.
Recent tests carried out in collaboration
with the Central Public Health Laboratory in London, UK, on many
strains of multi-antibiotic-resistant bacteria such as MRSA strains
MRSA, VRE and Acinetobacter baumarii have shown that these bacteria
have no resistance to honey. (These "superbugs" are a serious
clinical problem as infections with them often cannot be treated at
all with antibiotics.) All of the testing of sensitivity of
wound-infecting species of bacteria that we have carried out has
been done with honeys selected to have mid-range levels of
antibacterial activity. These have been found to have ten to fifty
times more activity than is needed to completely suppress the growth
of the bacteria tested. Although this may suggest that therefore
other less potent honeys would be suitable for use on wounds, it
should be taken into account that honey gets diluted by serum
exuding from wounds, and that the depth of penetration of an
effective level of antibacterial activity depends on the strength of
the activity on the surface.
The hydrogen peroxide generated in
honey is responsible for some of the other therapeutic effects seen
in wound treatment as well as for the antibacterial activity. It
stimulates the growth of the cells responsible for replacing damaged
tissue. Additionally it has an insulin-like effect on cells which
would be expected to be beneficial to the healing process as
application of insulin to wounds aids healing. It also stimulates
the development of new blood vessels, a key first step in tissue
regeneration. It serves as a messenger between the different types
of cells involved in the immune response of the body to infection.
It also activates protein-digesting enzymes in tissues which are
involved in the healing process. Although hydrogen peroxide is
generally an inflammatory substance, the enzymic generation in honey
gives only low levels. Also, antioxidants in honey prevent the
formation of free radicals which are responsible for this
inflammatory effect. The antioxidants in honey are also the likely
explanation of the anti-inflammatory action of honey.
The acidity of honey and its content of
sugars and other nutrients are also important for the promotion of
the healing process. Acidification of a wound prevents ammonia from
bacterial metabolism being harmful to the body tissues. It also
increases the release of oxygen from haemoglobin in the blood,
oxygenation of the tissues being essential for growth of new tissue.
Another important factor for growth of new tissue is a supply of
nutrients, usually limited because of damage to the underlying
circulation resulting from injury or infection. Honey will supply
the cells with a wide range of vitamins, amino acids and minerals.
It will also supply white blood cells with the glucose necessary for
their "respiratory burst" to destroy bacteria. Further, it will
supply nutrients to the cells by drawing serum out through the
tissue by osmosis induced by the high sugar content of honey. This
is what creates the moist environment for healing, preventing the
deformity that would result if the re-growth were forced down by a
dry scab forming on the surface. It also serves to create a film of
liquid between the tissues and the dressing, which allows the
dressing to be lifted off painlessly and without tearing off the
recently re-grown cells.
Another benefit is that it serves
to reduce swelling in the surrounding inflamed tissue, and thus
reduces a major cause of pain. The sugar content of honey also
eliminates the unpleasant odour associated with major burns and skin
ulcers, as the infecting bacteria use the sugar from the honey in
preference to amino acids from the serum and dead cells, from which
amines and sulphur compounds are produced.
Other traditional therapeutic uses of
honey, for peptic ulcers, diarrhoea, eye infections, and throat
infections, have also been researched to find evidence for their
effectiveness. Clinical trials have been reported in which honey was
found to be effective in the treatment of peptic ulcers and
diarrhoea, and a clinical reports of the use of honey for the
treatment of eye infections indicate that the treatment is
effective. Laboratory research has been carried out that
demonstrates that the bacteria that cause these infections are
sensitive to the antibacterial action of honey.
In addition, laboratory research has
been carried out to establish if there is a rational basis for
trialing honey treatment of fungal infections of the skin, for
protection of dental health, and treatment of mastitis in dairy cows
and goats. In all of these it has been found that the microorganisms
involved are sufficiently sensitive to the antimicrobial action of
honey for a good therapeutic effect to be expected.
Clinical trials are currently being
undertaken to measure the effectiveness of honey as a treatment for
persistently non-healing wounds, for eczema, and for mastitis in
dairy cattle.
All Articles in this section are
reproduced with kind permission of Professsor Peter
Molan, director of the research at the Honey Research Unit,
Waikato University, New Zealand.
Disclaimer
Note that we (Medicinal Honey Company
Pty. Ltd.) or the manufacturers of any of our products
accept no liability for any injury, loss, discomfort, etc., arising
from the use of any product supplied. You are strongly advised to
seek the advice of your medical practitioner before using any of our
products if you are presently taking any medication or if you are in
any doubt concerning their use for your condition.
Medicinal Honey
Company Pty. Ltd. presents these research articles on
the application of active for general interest only
and these articles are not intended to
constitute medical advice or to make medical claims. We should say
here, of course, that you should consult your doctor or health
practitioner before using Medigold  Australian Tea Tree
honey for any medicial condition.
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