American research finds scorpion toxin that may ease chronic pain
Pain and inflammation usually tie together to produce a protective/defensive response according to human biology. Researchers from the University of California-San Francisco (UCSF) have recently found a scorpion toxin that triggers pain in a novel way that promotes a better understanding of chronic/acute pain and could even lead to the development of new pain drugs.
The sensory protein TRPA1 – embedded in sensory nerve endings throughout the body – will open a channel that allows the flow of sodium and calcium ions into a cell if it encounters a harmful toxin, thus causing pain and inflammation. Surprisingly, the Australian Black scorpion’s “Wasabi receptor toxin” (WaTx), unlike many other peptide toxins, was able to penetrate a cell and attach to the TRPA1 in an unconventional method – it was seen to induce a pain response, without the inflammation. Acute pain, hypersensitivity to temperature/touch and significant swelling was observed when the researchers injected mustard oil, a plant irritant, into the paws of mice; but with WaTx, they researchers observed acute pain and pain hypersensitivities, but no swelling.
John Lin King, a doctoral student in UCSF’s Neuroscience Graduate Program, explains WaTx’s unique mode of action, “Nerve cells can release pro-inflammatory signals that tell the immune system that something’s wrong and needs to be repaired – this ‘neurogenic inflammation’ is one of the key processes that becomes dysregulated in chronic pain and pain hypersensitivity. Our study with WaTx suggests that you can decouple the protective acute pain response from the inflammation that establishes chronic pain.”
“Our findings also underscore the promise of TRPA1 as a target for new classes of non-opioid analgesics to treat chronic pain,” Lin King adds.
