Natural Products as Drugs - Biotechnology and Your Health: Pharmaceutical Applications - page 25

determine its structure, and develop reliable and economical ways
to produce it from inexpensive materials.
In some cases, the medical use of a plant extract was discov-
ered long after it had been used for other purposes. Morphine,
now used to treat severe pain, was isolated in the 19 th century
from opium, a drug that has been used and abused for centuries.
Several plant extracts now known to have effects on the heart
were used as arrow poisons by tribal peoples around the world. In
A . D . 1250, a Welsh physician wrote about the use of the foxglove
plant to treat accumulation of fluid in the tissues, which can be
caused by the weakening of the heart muscle. Digitalis, a heart
medication used today, was isolated from the foxglove plant.
Chemists isolated quinine, now used to prevent and treat malaria ,
from the bark of the cinchona tree, used for centuries by South
American tribes to treat malaria and to bring down fevers. Today,
these drugs are produced by chemical methods, without relying
on harvesting wild or cultivated plants.
FINDING MEDICINES IN NATURE
Plants have traditionally played a major role in medicine, with herbs
and other plants providing teas, balms, and salves. Although we
might like to think that modern science has led us away from these
seemingly simplistic sources for healing, one of the most effective
modern cancer drugs came out of a massive government search for
new cancer medicines from plants, a search that ranged around the
globe. Paclitaxel ( Taxol ® ), a drug used to treat cancer of the ovary ,
breast, and certain forms of lung cancer, was produced through a
joint effort of the National Cancer Institute (NCI) and the Depart-
ment of Agriculture (USDA). From the early 1960s to 1981, plant
experts at the USDA traveled the world searching for new plants,
and NCI scientists tested extracts of those new plants for the ability
to kill tumor cells. The chemical responsible for killing tumor cells
was then isolated from the extract. Although hundreds of thousands