Centipede venom fights pain

A chemical found in centipede venom wipes out pain just as well as morphine does, a study in mice shows.

When researchers injected mice with a molecule isolated from the venom of the Chinese red-headed centipede, mice showed fewer signs of pain in response to heat, acid and nasty injections, Chinese and Australian scientists report September 30 in the Proceedings of the National Academy of Sciences. In some tests, the compound, called Ssm6a, erased pain as well as, or better than, morphine.

Ssm6a is a protein fragment that blocks a pain-sensing channel called Na_V1.7. Pharmaceutical companies are in hot pursuit of molecules that do the same thing (SN: 6/30/12, p. 22). Because the channel resides mainly in the body’s peripheral nerves, compounds that block Na_V1.7 shouldn’t cause dizziness, drowsiness or other side effects of current pain-relief drugs that affect neurons  in the brain.