Photograph by George Grall, National Geographic
Updated October 4, 2012
The venom from one of the world's most venomous snakes could be the key to a new breed of painkiller, a new study says.
Pain-relieving compounds—called mambalgins—isolated from the venom of Africa's black mamba snake are as strong as some opiates, including morphine, without the risk of respiratory distress and other side effects common with pain-reducing drugs.
"It's remarkable that this was made possible from the deadly venom of one of the most venomous snakes," said study leader Anne Baron, of France's Institute of Molecular and Cellular Pharmacology. (See snake pictures.)
Prior studies have shown that certain snake venoms contain toxins that can evoke pain by activating acid-sensing ion channels (ASICs) in the central and peripheral nervous system. Baron and colleagues discovered that with the isolation of peptides they named mambalgins, pain can be minimized or even stopped by targeting and inhibiting certain ASICs within the body.
The new study tested this idea on mice.
"Pain pathways are pretty well conserved between mice and humans, making us confident that these peptides will also be efficient in humans," said Baron, whose study will appear tomorrow in the journal Nature.
(Also see "Human Bodies Make Their Own Morphine.")
Natural Toxins Long Used as Drugs
Venom from snakes and other creatures like spiders and scorpions have long been used for medicinal purposes, and much modern research has focused on the development of the poisonous substance into pharmaceuticals for a wider market.
Aspects of king cobra, copperhead, rattlesnake, and viper venom have been found to have an effect on a wide range of medical maladies, ranging from the dissolution blood clots to possibly slowing the growth of cancer cells.
"Animal venom toxins have a solid success rate [becoming] major drugs," said Zoltan Takacs, a herpetologist and toxinologist named a National Geographic Emerging Explorer in 2010. "There's no question this will continue, as the vast majority of toxins remain unexplored."
Animal toxins are especially valuable to biomedicine, Takacs explained, thanks to their selectivity and affinity. "Toxins are used for both drug target validation, to learn where exactly to aim your drug," he said, "and as a blueprint for crafting the actual drug."
Though the breakthrough is encouraging, Takacs cautioned against expecting quick drug development for human use. "To develop a new drug, you need 10 to 15 years, hundreds of millions of dollars," he said, "and you still have no guarantees."
Baron and colleagues plan to advance their findings to clinical levels, though any development will take a number of years. However, Baron said, they were issued a patent and the pain management drug development company Theralpha is currently working on developing the painkilling compounds.
Note: The cost of developing a drug was corrected from a billion dollars to hundreds of millions of dollars.
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