Healing
Cold Sores
Human trials follow up promising
pilot study
Further research on the use of tea
tree oil to treat cold sores is underway, with nearly 150 cold sore sufferers
recruited and more than 60 treated for a project running in Western Australia.
This trial follows an earlier pilot
study that showed that people who treated their cold sores using a gel
containing 6% tea tree oil up to 5 times a day had faster times to healing
(9 versus 12.5 days).
Researcher Dr Christine Carson says
these very promising results suggested this larger study was warranted.
"We are recruiting volunteers from
the Sir Charles Gairdner Hospital, The University of Western Australia
campus and the Perth metropolitan area for the trial.
"There is strong interest in treatments
for cold sores because 20% - 40% of people are prone to developing cold
sores because they carry the herpes simplex virus 1, which at this stage
has no cure," she said.
The trial will be completed late this
year with results available in 2002. The project is co-funded by RIRDC
and Australian Bodycare Pty Ltd.
Contact: A/Professor Tom Riley ph:
(08) 9346 3690, email: triley@cyllene.uwa.edu.au This current research
is being co-funded by RIRDC and Thursday Plantation.
The team has also applied for funds
to run further trials to test these findings in humans.
"Once underway we will be looking for
volunteers who are either sensitive to nickel or have other skin allergies
who wish to be test the effectiveness of tea tree oil to reduce swelling
and itching.
This research proposal has received
support from RIRDC, pending the signing of an agreement with a joint funding
partner," added Dr Finlay-Jones.
Contact: Dr Prue Hart Ph: (08) 8204
5414, Email: Prue.Hart@flinders.edu.au
Fungal
Treatments
Tests on tea tree oil show it works
Tea tree oil has been proven to be
effective in inhibiting a wide range of fungi found in our environment.
Laboratory trials at The University of Western Australia’s Department of
Microbiology show that tea tree oil kills yeasts, like candida, and dermatophytes,
that cause diseases such as tinea and ringworm.
Research leader Associate Professor
Tom Riley says the effect of different concentrations of tea tree oil on
the fungi has been laboratory tested and the way in which tea tree oil
inhibits growth of these organisms investigated.
"Results of test tube trials show that
yeasts (including members of the genera Candida, Cryptococcus, Rhodotorula,
Saccharomyces and Trichosporon) are inhibited by tea tree oil
in the range of 0.03% to 0.5%, and are killed by tea tree oil in the range
0.06% to 1.0%.
Similarly, filamentous fungi, some
of which are also known as dermatophytes, are inhibited in the range of
0.04% to 0.03% and killed in the range of 0.06% to 1.0%.
"These results provide the basic information
needed to develop and finally evaluate tea tree oil products for the treatment
of fungal infections." "There are a limited number of topical antifungal
treatments on the market and there is growing resistance to these products,
so finding alternative treatments would be very useful for people who suffer
as a result of infections with these types of fungi." said Associate Professor
Riley.
Fungi that lurk in air conditioning
In the latest research into the antifungal
activity of tea tree oil, an additional group of fungi have been tested.
They include a total of 78 isolates of Aspergillus flavus, Aspergillus
fumigatus, Aspergillus niger, Alternaria spp., Cladosporium spp., Fusarium
spp.
and Penicillium spp.
Researcher Kate Hammer says that some
of the aspergillus species can cause a disease called aspergillus or ‘farmers
lung’.
"Many of the organisms tested are also
found in air conditioning ducts and cause problems such as sick building
syndrome.
"Some companies are already using tea
tree products to reduce the bacterial and fungal load in air conditioning
systems, but to date there has been no hard data showing the effectiveness
of tea tree oil for this process," she said. "The good news is we are well
on the way to providing that evidence." This recent research into the fungicidal
effects of tea tree oil is cofunded by RIRDC and Australian Bodycare Pty
Ltd.
Contact: Kate Hammer ph: (08) 9346
1986, email: khammer@cyllene.uwa.edu.au
Opening
a World Market
High hopes for vaginal infection
trials
An important clinical trial has just
commenced to test the effectiveness of tea tree oil products in treating
two common vaginal infections (candida vaginitis and bacterial vaginosis).
This international trial will take
place at three sites - in Perth, Western Australia, Leeds in the UK and
Aalborg in Denmark.
Research Leader Associate Professor
Tom Riley says that bacterial vaginosis is the most common complaint that
women present to GP’s.
"In the US for example this problem
is responsible for something like 10 million GP visits by women each year.
Treatments for this condition are currently limited and there is a high
relapse rate after their use.
"If tea tree oil products are demonstrated
to be an effective cure then a large new market will be opened to the industry,"
he said.
Extensive protocol development has
been carried out with local, national and international collaborators in
the trial. Although timeconsuming, this will be critical to ensure that
the data from the studies are acceptable to national regulatory authorities
in Australia, the UK and Denmark.
The project is co-funded by RIRDC and
Australian Bodycare Pty Ltd.
Oral
Healthcare
Fighting oral microorganisms can
improve wellbeing
There are a large number
of bacterial species found in the mouth, with some of them causing a with
some of them causing a number of systemic problems including dental disease,
and even extending to diseases like bacterial endocarditis, a cause of
heart disease.
A project is underway at
The University of Western Australia’s Department of Microbiology to determine
the susceptibility of oral microorganisms to tea tree oil and to evaluate
its potential as a topical antimicrobial agent for oral infections.
Project Leader Dr Christine
Carson says to date their research shows that a number of Streptococcus
and Actinomyces species are susceptible to tea tree oil at concentrations
similar to those reported previously for other bacteria.
Other oral pathogens to be
laboratory tested include the following genera: Fusobacterium, Prevotella,
Peptostreptococcus, Haemophilus, Porphyromonas and Treponema.
This Project is co-funded
by RIRDC and Australian Bodycare Pty Ltd.
Contact: Dr Christine Carson, Ph:
(08) 9346 3288, email: ccarson@cyllene.uwa.edu.au
Skin
Sensitivity to Tea Tree Oil
Packaging important in avoiding
reactions
Research into skin sensitivity
to tea tree oil has come up with good evidence that storage conditions
of tea tree oil have a strong influence on oxidation of the oil, which
is linked to skin sensitivity.
Associate Professor Tom Riley
of The University of Western Australia’s Microbiology Department says that
while they know that the products of oil oxidation cause skin sensitivity
they are not yet sure which oxidation product is the main cause.
"The industry should look
at how it packages its oil. Clear packaging is not great, instead storage
and sale of pure oil in dark bottles is recommended to prevent oxidation.
It is also preferable to store the oil in small containers as the oil in
large bottles is exposed to air regularly over a longer period of time,"
he said.
Associate Professor Riley
also recommends that the pure tea tree oil be packaged with childproof
caps to prevent poisoning of young children.
Previous studies have shown
that only about 2% of people are sensitive to tea tree oil, but there have
been a few cases of severe reactions.
Associate Professor Riley
says that irritancy to tea tree oil is definitely concentration dependant
and the industry should get away from selling 100% oil and sell products
with around 5% tea tree oil.
Contact: A/Professor Tom
Riley ph: (08) 9346 3690, email: triley@cyllene.uwa.edu.au
Breeding
Success
Improved seed the only way to go
In 1992 the average plantation
production of tea tree oil was 148kg/ha. This was considered well below
potential and unviable during periods of low prices. Today the average
yield of improved stands of tea tree is more like 192kg/ha due to the establishment
of the Tea Tree Breeding Project.
The Rural Industries Research
and Development Corporation (RIRDC) and the Australia Tea Tree Industry
Association (ATTIA) recognised the potential to provide progressive, economically
significant gains in oil yield and quality of Melaleuca alternifolia when
they supported the first phase of breeding in May 1993.
Eight years down the track
the Tea Tree Breeding Project based at Wollongbar Agricultural Institute
recently had its second positive review.
The Tea Tree Breeding Project
has successfully released seed to the industry for the fourth consecutive
year. This brings a total of 7 kg of seed distributed, enough to plant
over 1000 ha of tea tree plantation. Improvements in yields of around 30%
have already been achieved and by 2003 the yield of oil is expected to
be 60% over 1992 levels.
Chairman of the Breeding
Committee and tea tree grower Richard Davis of G.R. Davis says the program
has both met and exceeded expectations.
"There is now industry-wide
recognition of the success of this breeding program. Everyone you talk
to at industry meetings, whether they be large corporate operators or smaller
operators, all say you would be mad to plant anything other than the seed
produced from the program." "The improvements are very obvious. Some people
are seeing a 40% to 60% improvement in yield from the seed that is only
supposed to be 17% to 20% improved. This shows it is almost certain the
program will result in the 60% yield improvement it aimed for.
"Up to the price crash all
the seed from the program was over-subscribed. Now there is a small amount
of seed still available because the demand for new plantations has slowed.
However, there will be continued
demand from existing growers looking to replant around 450 hectares each
year, and from all reports they will only be looking for the seed from
the breeding program.
"The project has brought
in around $270,000 in income so far and this shows that it will be feasible
in due course for the breeding program to be self-funding, which is very
unusual for a research project!" he said.
Where to from here?
The conclusions of a recent
economic analyses of the tea tree breeding program concluded that a third
phase (2001-2006) would be likely to yield significant benefits, with uptake
of new seed still likely to occur at oil prices ranging from $22/kg to
$16/kg. This compares with the uptake of current seed requiring a price
of $27/kg to be attractive to growers. In addition high-yielding materials
will be needed to keep producers in business, or attract new investors.
The proposed third phase
of the breeding program concentrates on work needed in developing orchards
and exploring cloning to deliver the highly improved germplasm that may
be essential to the future economic viability of the industry in Australia.
Contact: Dr Gary Baker,
Wollongbar Agricultural Institute, Ph (02) 6626 1224, email: gary.baker@agric.nsw.gov.au.
| INDUSTRY
SNAPSHOT
The Australian tea tree industry has
become an important regional industry in Australia with a farm-gate value
in excess of $20 million.
Approximately 90% of tea tree oil is
exported.
There are presently some 300 producers
in the industry with a total plantation of an estimated 6000 ha. |
Publications
Other RIRDC tea tree oil
reports:
