Rainforests May Hold Cancer Secrets
Sydney Morning Herald
Friday November 28, 1986
THE destruction of the world's tropical rainforests may be depriving future generations of a variety of valuable natural medicines, including some that might help cure cancer.
About 5 per cent of tropical plants, and only 1 per cent in the Amazon basin, have been examined for what the scientists call "biodynamics". Dr Michael Balick, of the New York Botanical Garden, says "probably most of them will be destroyed before we ever get to it".
Dr Balick, an ethnobotanist, and his colleagues are trying to identify Amazon rainforest plants that might contain possible anti-cancer agents.
The project, to be conducted with the National Cancer Institute, calls for garden scientists to collect 1,500 plants a year for NCI researchers to test.
A number of major medicines in use today were isolated from plants. Aspirin is a good example, as is digitalis, which is still used for angina. The most dramatic recent example may be a cancer drug from the common ground cover rosy periwinkle. About 25 years ago this plant gave science one of its best weapons against childhood leukemia - a pair of chemotherapeutic agents called vincristine and vinblastine.
Now in their search for new drugs Balick and other staffers on the Amazon project plan to go first to small farmers and native tribes in the region.
"They have an incredible wealth of knowledge about their environment and about the plants in the environment," Dr Balick said. "We basically just ask'Can we learn from you?'
"If there is a medicine man or shaman with an ethnopharmacopeia developed over the years, we'll focus in on those plants so we'll get a little headstart."
"Tropical plants are essentially little chemical factories that have evolved over thousands of years of actually fighting with their environment, and some have evolved a number of very complex chemicals.
"Over evolutionary time, for example, an insect will eat a plant, and if the plant or its progeny don't develop a defense, it will be eaten to extinction."
Once Dr Balick and the small group of researchers collect stems, leaves, flowers, roots, seeds and fruits of plants, they will send them to an NCI laboratory, where new techniques of chemical analysis will determine if there is a potential agent to fight some of the 400 or so known cancer cell lines.
© 1986 Sydney Morning Herald