A peptide found in centipede venom shows promise in targeting a key nerve channel in mice, and could lead to a powerful medication for people suffering from chronic, debilitating pain.
The research, published today in Proceedings of the National Academy of Sciences, shows how gene mutations in the NaV1.7 sodium ion channel result in some people being unable to feel pain. Scientists have found that the peptide Ssm6A, found in centipede venom, can shut down this channel, providing clues about how to treat severe, persistent pain.
Glenn King, a molecular scientist at the University of Queensland in Australia and one of the study's authors, told Healthline the molecule appears to be very safe and does not cause side effects, even at doses 10 times higher than what's needed.
“I am most excited by the possibility that Ssm6a might be suitable for treating patients with long-term chronic pain whose condition cannot be managed with current analgesics, particularly patients with neuropathic pain,” King said. “Moreover, it is hoped that Ssm6a will not cause problems such as tolerance, addiction, and abuse that are associated with opioid pain killers, such as morphine and oxycodone.”
More Powerful Than Morphine
King said he expects the peptide could prove more powerful than morphine in treating all types of pain, including pain caused by nerve damage, cancer, and surgery.
Much more research needs to be done, King said, including exposing mice to pain comparable to that caused by rheumatoid arthritis, cancer, and neuralgia. He said that if all goes well, clinical trials in humans could begin in two years.
Although the peptide occurs naturally in centipede venom, it can also be made through a process called bacterial fermentation, so large-scale production should not be a problem.
Lai Ren, one of the study's authors from the Chinese Academy of Sciences, told Healthline that centipede venom extracts already are used in traditional Chinese medicine to treat tetanus, convulsions, and heart attacks.
“Centipedes are excellent predators. Their prey includes both vertebrates and invertebrates, including bats, rats, amphibians, reptiles, and insects," Ren said. "Centipede venom causes instant rigid paralysis in envenomated houseflies, cockroaches, and crickets, implying that there are neurotoxins in centipede venoms that provide an efficient means of rapidly paralyzing prey.”
King said venomous arthropod predators, such as centipedes, spiders, and scorpions, are ancient beasts, perhaps as as much as 450 million years old. They have evolved exceedingly complex venoms that target the nervous systems of their prey.
“Since the nervous system is heavily reliant on ion channels for conduction of electrical signals, most of the small peptides in the venoms of these animals are ion channel modulators," Ren said. "Thus, these venoms are a superb natural resource if one is looking for ion channel drugs.”
Snakes and Snails and Peppers, Oh My!
Numerous drugs made from snake venoms are already on the market, including Captopril for hypertension. Prialt is a pain reliever made from the venom of a cone snail.
Diana Bautista, a molecular scientist at the University of California, Berkeley who was not involved in this study, told Healthline that recent research on the NaV1.7 pathway has made it an attractive drug target for pharmaceutical companies.
She said the research showing the power of centipede venom has legs. “I am excited about it," Bautista said. "When you discover a toxin like this that has a very specific target, it could impact patients in several ways.”
Bautista said the research offers an important glimpse into how the ion channel is regulated, and could provide a blueprint for creating powerful medications. Bautista is currently examining how extracts from spicy Szechuan peppers impact NaV1.7.
“This looks very promising,” she said.