Many plants produce special substances in their roots,
leaves, flowers, or seeds that help them to survive. For example, some plants
make nasty-tasting substances to defend themselves against plant-eating
animals. Since earliest times, people have gathered these substances to create
herbal medicines to treat certain diseases. Many of the powerful drugs used in
modern medicines originated in plants. Today’s plant-based drugs treat a
range of diseases, from headaches to cancer.
Rainforest people possess
valuable knowledge about medicinal plants. With proper research, scientists
believe they might find cures for some of the world’s deadliest diseases
among rainforest plants. Some of these plants have not even been discovered
yet. Unfortunately, rainforests are being destroyed. As they disappear, so do
thousands of possible life-saving drugs.
Aloe vera is the thick juice of the aloe, a type of plant that comes
from tropical Africa but is also cultivated elsewhere. The juice contains a
chemical called alonin, that has been used in cosmetics and medicine. Its
healing properties have made it especially useful as an ingredient for lotions
and gels that soothe burns, including sunburn. It can also be used to repel
biting insects.
Also known as toothpickweed, this Mediterranean herb contains a
chemical that opens up blood vessels, improving blood flow to the heart, and
opens the breathing tubes of the lungs. The chemical has been used in medicines
to treat asthma and angina (pain due to heart problems).
The Madagascar periwinkle is the source of drugs used to treat
diabetes and certain cancers, such as Hodgkin’s disease and acute
leukaemia. The drug for treating Hodgkin’s disease has increased
patients’ chances of survival from one-in-five to nine-in-ten.
The bark of this tropical tree contains a drug called quinine.
Quinine is used in the prevention and treatment of malaria, a deadly disease
carried by mosquitoes. Malaria is responsible for thousands of human deaths
around the world every year.
This little plant contains a chemical called colchicine, which has
been used to treat rheumatism and gout. As it tends to prevent cells from
dividing too quickly, colchicine has also been used to suppress some types of
cancer
The coca plant grows naturally in South America and is the source
of the drug cocaine. Although cocaine can be abused and is associated with
addiction, it has also been used responsibly by doctors as a local anaesthetic
and for pain relief.
Opium is a pain-killing drug extracted from the unripe seed pods
of the opium poppy. In 1806, a German scientist isolated the drug morphine from
opium. Morphine and its derivatives, such as heroin and codeine, remain
important pain relievers.
Meadowsweet is a European wildflower that grows in wet soils and
marshes. It has been used for pain relief in the treatment of many conditions,
including headaches, arthritis, and rheumatism.
Rauvolfia is a small, woody plant that grows in tropical
rainforests. It contains reserpine, a chemical that effectively relieves snake
bites and scorpion stings. Reserpine was the first tranquillizer used to treat
certain mental illnesses. It also lowers blood pressure.
