Plants That Changed The World

FROM DART POISON TO MUSCLE RELAXANT

In the sixteenth century, a group of Spanish explorers traveled the Amazon River.

During the voyage, one explorer was hit in the hand by an arrow and died soon after. The culprit
was curare, used widely as an arrow poison by many Amazon Indian groups (as it is still used by a
few today).

The complex processes used to make curare were a guarded secret. Often 30 or more ingredients
could be found in one recipe.

Indigenous Amazonians often mixed plants of different genera to concoct their potent toxins; their
skill and knowledge in safely preparing these poisons is a testimony to their incredible ingenuity.

Amazonian curares are divided into two groups based upon the container the plant is stored in: pots
or tubes.

Pot curare in the East Amazon is predominately from the species Strychnos guianensis.

Tube curare in the West Amazon is from Chrondrodendron tomentosum.
(The curare in modern medicine is made from the latter species, therefore, its name: tubocurarine.)

For many centuries the exact content of curare remained a mystery to Western observers; not until 1800 did Alexander Von Humboldt witness and document the preparation of curare by the Indians
from the Orinco River.

In 1814, an explorer named Charles Waterton injected a donkey with curare. Within ten minutes, the donkey appeared dead. Waterton cut a small hole in her throat and inserted a pair of bellows, then pumped to inflate the lungs. The donkey held her head up and looked around. Waterton continued artificial respiration for two hours until the effects of curare had worn off. Curare was found to block
the transmission of nerve impulses to muscle, including the diaphragm muscle, which controls breathing.

In 1939, the active ingredient of curare was isolated.

In 1943, it was introduced successfully into anesthesiology.

Curare provided adequate muscle relaxation without the depressant effect of deep anesthesia induced by ether or chloroform.

Over the last 20 years, physicians have used curare to ease the stiffened muscles caused by polio and to treat such diverse conditions as lockjaw, epilepsy, and cholea (a nervous disorder characterized by uncontrollable muscle movements).

Eventually more effective treatments were found for these illnesses, but the active ingredient of curare, d-tubocurarine, led to the skeletal muscle relaxant Intocostrin, used in surgery ever since.

Synthetic analogs of d-tubocurarine are used tens of thousands of times per day in the operating room.