Tea Trees of
Australia and New Zealand
Tea Trees are small trees and shrubs of
the Leptospermum genus which belong to the broader category of the
Myrtle family. Within the Leptospermum genus there are 79
species found throughout Australia with one species
found growing in New Zealand.
Out of all these 79
species only two species have been found to have strong
antibacterial activity. Both species have unique phytoactivity
and hydrogen peroxide releasing ability.
TEA TREE or
Golden Tea Tree or Jellybush is
Australia's answer to Manuka. It produces a honey that has
exceptionally high levels of antibacterial activity.
It has a
wide distribution within NSW and Queensland, but like Manuka, its
New Zealand relative its activity varies with the areas in which it
grows. Its strongest and most potent activity is found in north
Manuka or Tea Tree is found throughout New Zealand
growing under a wide variety of conditions. Its activity varies
depending on where it grows, with some regions of New Zealand
producing high activity while other areas produce non-active Manuka
Although called New Zealand Manuka this species is also
found growing in Australia, in the states of Tasmania,
Victoria and NSW.
What does the word 'active'
mean in relation to Leptospermum honey?
The word 'active' refers to New Zealand
and Australian Leptospermum honeys ability to kill or inhibit the
growth of many bacteria and fungi, the honey often being
termed either antibacterial or antimicrobial, depending
on what organism it is being used against. This
'Activity' or antibacterial quality of Leptospermum honey is
determined by specific laboratory tests.
The two types of 'activity' of
- The Hydrogen Peroxide
The first and most common form of
antibacterial activity is due to the slow release of
hydrogen peroxide with the help of the enzyme glucose oxidase
present in honey. This release occurs when the honey
becomes diluted with serum at the wound site or when honey is
diluted by digestive fluids after eating. This slow release is
very beneficial to the healing process as just enough hydrogen
peroxide is released to kill bacteria and fungi without damaging
sensitive wound or digestive tissues. However its ability to
release hydrogen peroxide is short lived as hydrogen peroxide
is quickly depleted as the honey becomes
There is a great variation in the hydrogen
peroxide release ability of different honeys with some
honeys being no more antibacterial than sugar. The reason for
this variation is probably due to the fact that the enzyme
responsible for the release of hydrogen peroxide is sensitive to
both heat and light and also to other chemical compounds
within some honeys. This is why when some honeys are tested
in laboratories they show no sign of hydrogen peroxide
peroxide antibacterial activity is found in a few honeys
world wide but is generally very high in both the
Australian Golden Tea Tree (L. polygalifolium) and
New Zealand Manuka (L. scoparium).
- The Non-Hydrogen Peroxide
Activity or the Unique Phytoactivity (Unique Manuka Factor
The unique phytoactivity is an
unidentified natural plant antibacterial compound peculiar to
Leptospermum plants. So far researchers world wide have not
been able to identified the compounds that are specifically
responsible for the Unique Phytoactive property, which inhibits
the growth of bacteria and
This antibacterial component is more stable
than the antibacterial effect of the hydrogen peroxide releasing
enzymes and does not become effected by dilution. It is
therefore better suited for longer term use in deep wounds and
This unique phytoactivity has
been given a strength rating from 10+ to 20+ with
20+ being the strongest available on the market.
This was first
discovered in New Zealand where research was first carried out on
manuka honeys' antibacterial effects but is now used in reference
to the Australian Leptospermum plant activity.
The power of
Tested to ensure high levels of
Some Leptospermums contain
both types of activity. They combine the benefits of both the
hydrogen peroxide activity as well as Non-hydrogen peroxide
activity or the unique phytoactivity.
Leptospermum honey has this unique phytoactivity rating it will also
have a Hydrogen Peroxide activity rating although this is generally
not shown with the rating value.
All activity ratings of
NZ manuka and Ausrtralian Golden Tea Tree honeys are determined at
special laboratories designed to measure the activity of different
types of honeys.
An Australia or New Zealand
Leptospermum Honey which has been tested for the Unique
Phytoactivity and has a symbol of 10+,12+, 15+ ,18+ or 20+ has both
types of activity present and is preferable to honey that has not
undergone laboratory testing.
The activity rating symbol of 10+,12+,
15+ ,18+ or 20+ is in reference to the honeys antibacterial
strength which is compared to the sterilising ability of the
hospital antiseptic phenol. A 10+ active honey is equivalent in
antiseptic strength to a 10% solution of Phenol whereas
a 20+ active honey is equivelent in antiseptic strength
to a 20% solution of Phenol.
Both 'phytochemical compound'
and 'active plant factor are terms used by the researchers and the
scientific community to describe the antibacterial action of