Spider venom isn’t normally something you want in your body, but in some cases there might be exceptions. Australian researchers have now identified two peptides from tarantula venom that show promise in blocking organ pain, working particularly well in mouse models of irritable bowel syndrome (IBS).
A surprising amount of research lately is finding positive uses for compounds found in spider venom, including potential treatments for skin cancer, stroke damage, and arthritis. In fact, earlier this year the researchers on the new study found a pain-relieving mini-protein in the venom of the Chinese bird spider.
Now, the team has identified new molecules in a different spider species that can target visceral pain – that which affects the internal organs, often triggered by gastrointestinal and bladder disorders.
“Internal organs have a complex network of sensory nerves that have a wide array of voltage-gated ion channels and receptors to detect stimuli,” says Stuart Brierley, an author of the study. “The hypersensitivity of these nerves in disease often contributes to the development of pain.”
So the team set out to investigate which peptides could help treat visceral pain by selectively blocking related sodium ion channels. Ideally, they also wouldn’t affect other channels, such as those in the heart.
After screening 28 spider species, the team found a particularly promising candidate in the venom of the Pinkfoot Goliath tarantula. Found in Venezuela and Brazil, this is one of the biggest spiders in the world, with a leg span measuring around 30 cm (11.8 in).
The researchers found two peptides, named Tap1a and Tap2a, which were very effective at inhibiting the ion channels associated with pain. In tests on mice modeling IBS, the team found that Tap1a was particularly potent, almost completely reducing chronic visceral pain caused by the illness.
Of course, any treatment based on the findings would be a long way off, since they would need to advance through further animal trials before even reaching human testing – and then there’s no guarantee that the results would carry across to our biology. Still, it’s an intriguing start that could teach us other things as well.
“We now have a really strong understanding of the structure and function of these spider venom peptides,” says Richard Lewis, lead researcher on the study. “The highly selective ones have potential as treatments for pain, while others are useful as new research tools to allow us to understand the underlying drivers of pain in different diseases.”
The research was published in the journal Pain, and the team describes the work in the video below.
Source: University of Queensland