Curare
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| Ilustration of a plant used to make curare |
Throughout time humans have relied
on Nature for their basic needs for the production of food-stuffs,
shelters, clothing, means of transportation, fertilizers, flavors, fragrances and medicines.
Curare is a mixture of plants from South America and is used as a paralyzing poison by South
American indigenous people, especially for hunting purposes. Arrows or darts
shot at the prey are dipped in curare, which leads to asphyxiation owing to the
inability of the victim's respiratory muscles to contract. The curare from
eastern Amazonia comes from various species of
Strychnos (family Loganiaceae) plants that contain chiefly quaternary
alkaloids with neuromuscular blocking action. The use of curare by Indians
makes a good example of the prelude of biotechnology using venoms. Indeed, in
this sense, the Indians can be considered the precursors of toxicologists in South America (LIMA et al., 2010). Based on this effect,
curare started to be study by many researches.
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| Amazon indian using a narrow with curare to hunt |
In the late-1930s and early 1940s, the
American pharmaceutical industry launched the first modern paralyzing
drugs based on indigenous South-American arrow-poisons, curare.
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| Distribution map of the plant in the South America |
Curare never became a therapeutic drug;
instead, it became a valuable tool that facilitates medical
interventions, just as it facilitated animal experimentation. Its
entry to modern medicine took place in the early 1940s, and its most
prized application today is in surgery, where curarizing drugs
complement anesthesia by imposing an utter stillness on the patient,
leaving the body passive and pliant. Abdominal muscles relax and
yield, and involuntary movements and contractions disappear.
Classified as "surgical muscle relaxants," these modern
drugs have made surgery safer by reducing the need for dangerously
high levels of general anesthetics to achieve the same end (TRAUTMANN,
1982).
Preparation of the Curare used by Huaorani in the Yasuni.
References:
Lima, M. E., Forte-Dias L., Carlini C. R. and Guimaraes J. A. Toxinology in Brazil: A big challenge for rich biodiverity. Toxicon, 1084-1091, 2010.
Manalis R. S. Voltage-dependent effect
of curare at the frog neuromuscular junction. Nature, 267, 1977.
Trautmann, A. Curare can open and block ionic channels associated with cholinergic receptors. Nature, 298, 1982.