It is said that when the wife of the Spanish viceroy of Peru fell ill with malaria in the 1600s, an Indian healer treated her with the bark of the cinchona tree. Whether this tale is true or not, the drug was then taken up by Europeans, who called it 'quinine', and it has been used to treat the disease ever since.

Indigenous groups, who have an intimate knowledge of their surrounding ecosystems, rely on nature for many aspects of their daily survival, including medicines. Western doctors owe these groups a much greater debt than they usually acknowledge.

Amazonian peoples in Brazil and Peru, for example, have long used the roots of the Chondrodendron vine for treating fevers and snakebites, and as a weapon. Hunters use arrows dipped in a liquid extracted from the roots. Once wounded, their prey falls to the ground and dies within seconds. Western scientists have adapted the drug, called curare, to make modern anaesthetics, and to treat multiple sclerosis and Parkinson's disease.

Ancient remedies
Similarly, indigenous peoples in Brazil have long employed the jaborandi plant for medicinal purposes, dubbing it the 'slobber-mouth plant' because it induces the rapid production of saliva and sweat. It is now used in Western medicine to treat cancer patients who suffer from dry mouths and throats as a result of radiation therapy, and by people who have Sjögren's syndrome, which prevents them from producing enough saliva. The plant helps to relax the eye muscles, and has been adapted for use in eye surgery and the treatment of eye diseases.

On the other side of the world, a substance called rauwulfia - made from the snakeroot plant that grows in the forests of India - has been used for thousands of years to treat mental and nervous illnesses. Western scientists adopted this indigenous cure in the 1940s.

Harvesting for health
Local medicines can be cultivated, or gathered from the wild. Many rainforest tribes maintain gardens to harvest important plants, and in South Africa people grow pepper bark trees and African ginger for medicinal use. However, in Indonesia, there is no need to raise fields of alang-alang (used to treat hepatitis), as this variety of cotton grass is one of the most common groundcovers in the country.

Around 25 per cent of the pharmaceutical drugs used in the West today come from plants, and many more are being developed as medicines of the future. For example, scientists believe that poison from the Epipedobates tricolor frog,
which indigenous Ecuadorians use to make poison arrows, could give rise to a new painkiller to replace the use of morphine.

Local cures
Some 80 per cent of the world's people rely on their own culture's knowledge of medicines available from nature. Many cannot afford modern chemical medicines, but local treatments can often do the job as well or better. An investigation in Madagascar found that local cures, such as ginger for travel sickness and Burasaia sp. for fever, were more effective than their chemical alternatives.

The wealth of biodiversity in our planet's wilder places may well provide modern medicine with many of the cures of the future, as well as continuing to serve those who live among it and know it best.