Christine Soares, Kerry S. Matz Popular Science
A race to
find the next wonder drug is taking place at the bottom of the
ocean and a snail is in the lead.
Elan Pharmaceuticals—one
of the many pharmaceutical companies probing sponges, corals,
microbes, and other denizens of the sea—will likely get approval
from the Food & Drug Administration to market ziconotide,
a powerful painkiller that the company developed from the venom
of the Conus magus snail. Initially, ziconotide will be targeted
to patients suffering severe chronic pain—a population of
more than 1 million Americans alone. In clinical trials, it proved
1,000 times more potent than morphine, but with negligible side
effects, and patients never developed a tolerance.
Ziconotide’s
secret: It blocks communication between pain-sensing nerve cells
and the spinal cord neurons that relay those signals to the brain.
Such exquisite precision is the human chemist’s Holy Grail,
and the snail’s way of overcoming its speed handicap. "Because
it is problematic for an animal that can’t swim to capture
fish, snails have clever strategies," explains University
of Utah biologist Baldomero Olivera, who first isolated the venom
component that became ziconotide. The snail paralyzes its prey
by injecting venom with a harpoon-like organ before reeling it
in.
The drug is
a synthetic version of just one peptide from among more than 100,
which together make Conus magus venom a highly toxic cocktail.
"They have 55 million years of natural selection. That leads
to a lot of sophistication."
The Cone snail
family—which includes more than 500 distinct species, each
of which produces a unique venom—is sure to yield additional
new drugs. Ziconotide is already in trials for broader indications.
Australian researchers are reportedly developing a painkiller
that is even more powerful than ziconotide, and a Utah biotech
company expects to begin trials of an anti-epileptic this year.
A powerful new painkiller comes from venom
that an Indo-Pacific cone snail uses to paralyze its prey.
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