Discovering a Natural Painkiller: The Stinging Tree

Researchers (Professor Irina Vetter and her team) from UQ’s (The University of Queensland) Institute for Molecular Bioscience have uncovered a novel pain pathway in the Australian stinging tree, which could lead to new, non-opioid methods of Pain relief ().

Professor Vetter said the plant’s toxins - named gympietides in earlier work by the team - interact with nerves after being injected by fine needle-like hairs on the leaves ()().

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‘Discovery of a unique pain pathway in the venom of an Australian stinging tree could pave the way for new, non-addictive painkillers, according to researchers.’

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“The gympietide toxin in the stinging tree has a similar structure to toxins produced by cone snails and spiders, but the similarity ends there,” Professor Vetter said.

“This toxin causes pain in a way we’ve never seen before.”

Many toxins cause pain by binding directly to sodium channels in sensory nerve cells, but the UQ researchers have found the gympietide toxin needs assistance to bind.

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“It requires a partner protein called TMEM233 to function and in the absence of TMEM233 the toxin has no effect,” Professor Vetter said.

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“This was an unexpected finding and the first time we’ve seen a toxin that requires a partner to impact sodium channels.”

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The team is working to understand whether switching off this pain mechanism might lead to the development of new painkillers.

“The persistent pain the stinging tree toxins cause gives us hope that we can convert these compounds into new painkillers or anesthetics which have long-lasting effects,” Professor Vetter said.

“We are excited to uncover a new pain pathway that has the potential for us to develop new pain treatments without the side effects or dependency issues associated with conventional pain relief.”

References:

Pain-causing stinging nettle toxins target TMEM233 to modulate NaV1.7 function. nature communications - (https://www.nature.com/articles/s41467-023-37963-2)
Neurotoxic peptides from the venom of the giant Australian stinging tree - (https://www.science.org/doi/full/10.1126/sciadv.abb8828)
Native stinging tree toxins match the pain of spiders and scorpions - (https://imb.uq.edu.au/article/2020/08/native-stinging-tree-toxins-match-pain-spiders-and-scorpions)

Source-Eurekalert