Bush medicineBush medicineBush medicineBush medicineBush medicineCuriously there is little evidence thatAboriginal people used tea tree oil for itspowerful anti-fungal and anti-bacterialproperties. The species used commercially forthis purpose is Melaleuca alternifolia, a smalltree found in northern New South Walesand southern Queensland. Its germicidalproperties were discovered in the 1920s.Cajuput oil is made from the weepingpaperbark (M. leucadendra) and thecajuput (M. cajuputi). In northern Australia,the leaves of several Melaleuca specieshave been used traditionally for treatment ofcoughs, colds and on sores and burns, eithercrushed and inhaled or soaked in water tocreate an infusion. The aromatic oils stimulate cells in thethroat to produce more lubricating fluids thus easingirritations which cause coughs.

Hyoscine is thechemical whichachieved suddennotoriety recently whenlarger than normaldoses in Travacalm

tablets caused severeillness in a number of

people. Interestingly, thischemical is found in a common rainforest tree known

as soft corkwood (Duboisia myoporoides). Indeed, whenthis tree was hybridised with a closely related species lastcentury the result contained more hyoscine than any otherknown plant. It was grown commercially to makeophthalmic and sedative drugs, before synthetic versionsof the compound were developed. Extracts from the plantdilate the pupil – useful in eye surgery – and during WorldWar II considerable quantities of hyoscine were exportedto treat travel sickness introops and shell shock. In1989, 500 tonnes of driedand powdered leaves wereexported to pharmaceuticalcompanies in Germany andSwitzerland.

Soft corkwood is poisonousto stock and has beenblamed for at least onehuman death, in 1987, whena man experimentally ate some leaves. Interestingly, it isclosely related to a desert shrub, pituri (Duboisiahopwoodii) which was valued as a narcotic and widelytraded by Aboriginal people in days gone by.

Barringtonia racemosa is known as the fishpoison tree because chemicals, saponins, inthe bark stun fish when put in the water. Thistree was also used in India as a fevertreatment and is now known to haveproperties similar to quinine, the anti-malarialdrug extracted from South American trees.

Hyoscine is an alkaloid, a group ofchemicals which are found in a numberof plants and which have a potent effecton the human central nervous system;well-known alkaloids include strychnine,morphine, cocaine and nicotine.Alkaloids in native plants do not seemto have been important as traditionalmedicines, perhaps because of thedifficulty of determining safe doses.

The large leaves of the cotton tree (Hibiscustiliaceus) can be used as dressings onwounds. The leaf is simply heated over thefire and pressed on to the injury until it

sticks, stopping the flow of blood. The flowerbuds of this tree are used in Hawaii as a mildlaxative for children. For older children andadults the little white, dome-shaped ‘bump’inside the bottom of the flower is used forsame purpose. The bark of the stem is usedfor congested chests and for a motherdelivering a baby.

Cycad plants are very toxic although the seedswere an important traditional food, when properly treated.The seeds of some species, however, contain an antibiotic.

She oak (Casuarinaequisetifolia) grows commonly

along the back of beaches. The inner bark,which is a pinkish colour, can be ground up

and used to relieve the pain of a toothachewhen pressed on to the affected tooth. When

infused in water, it can be used as amouthwash to relieve a sore throat – but should

not be swallowed.

Owning the knowledgeAn international study found that about three-quartersof plant-based drugs developed by pharmaceuticalcompanies had already been known and used astraditional medicines. When looking for sources of newdrugs, pharmaceutical companies often rely onindigenous knowledge – it saves a lot of time. Havingfound an organism, the companies must break it downinto its various components and search for the onewhich is active. This may then be made into a drug. Thisprocess can be time-consuming and expensive.Nevertheless, in the end it is usually only the drugcompany which makes the profit – sometimes enormous– while the people who made the initial discoveries gainnothing. The company may even take out a patent onthe plant in question and it is not unknown for thetraditional owners to be then charged a royalty for usingit. Referred to as biopiracy, this trend is on the rise ascompanies increasingly take out patents on organisms,some of them common traditional food and medicineplants. See http://twm.co.nz/CptHook.htm for moreinformation.

An ABC Radio National Background Briefing programon October 13 2002 looked at the problems associatedwith bioprospecting and indigenous rights. A transcriptof the program can be found on www.abc.net.au/rn/talks/bbing/stories/s701553.htm

The core of the trunk ofcertain pandanus trees,notably screw palm/pine(Pandanus spiralis) wastraditionally used for anumber of complaints.Pounded and/or boiled, itwas particularly used fordiarrhoea and stomach painbut also for mouth sores andtoothache and to relieveheadaches and ’flu. In somecases the pith from the proproots, which support themain trunk, was used. Thereare records from GrooteEylandt, in the NorthernTerritory, of pandanus seedsbeing consumed for

contraceptivequalities,but noevidenceto supporttheireffectiveness.

Stinging trees (Dendrocnidespp) are to be avoided, due tothe pain caused by the finehairs in the leaves. These hairshave cell walls full of silica andcontain a sap which acts on thenerve-endings in human skin,causing pain for many months. However, the leaves wereused traditionally as a cure for rheumatism. They wereapplied directly to the affected area, but, perhaps lesspainful, were sometimes pounded and boiled first.

Thesandpaper fig (Ficusopposita) has, as the namesuggests, leaves which areas rough as sandpaper. Theyare used, traditionally, totreat fungal skin infectionssuch as ringworm (which isnot a worm). The affectedskin is abraded with theleaves until quite raw andthe area then covered withthe milky latex from the plant.Alternatively the area maybe covered with a greenants’ nest. The stings andthe formic acid from the antsare very painful butapparently a very effectivecure.

Cheesefruit (Morinda citrifolia) isbottled in Fiji and other Pacific Islands tobe sold commercially as ‘cheesefruit juice’,earning over US$1billion over five years

for the company named after the plant,Morinda Incorporated. Thejuice is sold as a performanceenhancer and antioxidant.Commercial drugs derived fromthe roots and trunk are used totreat high blood pressure.

The ripe fruit has an unpleasant smell so, notsurprisingly perhaps, this is when it is used as amedicine – as a treatment for common cold, ’flu, diarrhoeaand asthma as well as for wound treatment. It is said tohave a slight anaesthetic effect which provides instantrelief for sore throats. Mixed with coconut milk, it is givenas a relief from ciguatera in the Torres Strait. Leaves andfruit can be crushed and inhaled or rubbed on the chest.The bark of this tree is used to reduce fever and theleaves as poultices. In Hawaii, where it is known as‘noni’, the unripe fruit is pounded with salt and themixture put on deep cuts. Ripe fruit has also been used asa poultice to draw out pus. Even more claims are made forthis plant, but as with most ‘magical cures’ they haveattracted scientific controversy. For more information onthis see www.sgapqld.org.au/bushtucker.html

Latex from a number of plants,including figs and banana bush

(Tabernaemontanapandacaqui) (left) has been

used traditionally onsores and wounds.Recent studies have

shown that these plantscontain potent compounds by the

name of proteolytic enzymes. There is afine line between harmful and helpful chemicals. Latexfrom many plants can cause blindness. The banana bushis related to the highly poisonous oleander and the‘bananas’ are named for their shape, not their edibility.Latex from macaranga (Macaranga tanarius) is very

sticky and waterproof. Itcan be used on deep cuts,holding the skintogether likestitches.

Banana bush

Sandpaperfig