Spiders, an unwelcome guest in many homes, could gain a new reputation — as a welcome source of pain relief.
Spider venom contains thousands of proteins, among them some helpful molecules that may someday be made into powerful painkillers.
Such products could greatly benefit millions of chronic-pain sufferers whose discomfort does not respond to any of the usual medications. In the U.S. alone, the costs of chronic pain are estimated to top $600 billion a year in lost productivity and medical expenses, more than the price tag for cancer, heart disease and stroke combined.
Spiders would appear unlikely to be able to offer any help. Many of the proteins in venom activate pain pathways, causing paralysis and muscle spasticity in spiders' prey. And for people, spider bites can be excrutiatingly painful.
But investigators at the Institute for Molecular Bioscience at Australia's University of Queensland, who analyzed the venom of 206 spider species, identified seven compounds among the thousands in the venom samples that actually block pain signals from reaching the brain. Their findings were published in the British Journal of Pharmacology.
Julie Garb, who did not participate in the study, is a spider researcher in the biology department at the University of Massachusetts in Lowell, with a particular interest in venom.
"If you could take those toxins that block those channels and kind of turn it into a medicine, then you know that would cause those individuals to not be able to sense the stimulation of those neurons that would normally cause pain," she said.
It's estimated that there are 9 million proteins in the venom of the world's 45,000 spider species. Only a tiny fraction, .01 percent, of the peptides have so far been investigated for biological activity, according to Garb.
"But then there could be just one component that has a positive, beneficial medical effect, so they are trying to isolate exactly what that is," she said. "So if you knew exactly what that is, then you could manufacture it as a drug."
The Australian scientists suggest that the technique they used to screen spider venom reportedly could be used to test other compounds, identifying helpful ones that might be used to make new drugs.