Tarantula venom could help provide relief for patients suffering from Irritable Bowel Syndrome

Researchers from The University of Adelaide in South Australia found that a specific peptide in the spider venom could be used to understand how people sense pain.

Picture: Tracey Adams

Two toxins from the tarantula species Heteroscodra maculata were found to specifically target Nav 1.1, a voltage-gated sodium channel in the nervous system to initiate the electrical impulses that signal pain.

Associate Professor Stuart Brierley said the study demonstrated that Nav 1.1 contributed to mechanical, but not thermal, pain signalling.

“Using the highly specific peptide in the spider toxin we were able to work out how pain nerve fibres signal in a healthy situation and also in chronic abdominal pain such as what you see in Irritable Bowel Syndrome (IBS),” Assoc Prof Brierley said.

“We found that the spider toxin was able to cause a lot more pain in the IBS state than what it was in the healthy state.

“It’s important to note that because of the studies we should be able to develop treatments for IBS based pain – blockers for Nav 1.1 that only target the peripheral and don’t go to the central nervous system.”

The causes of IBS are still unknown but it affects about 10 per cent of people globally.

Chronic abdominal pain is the predominant symptom of IBS.

Assoc Prof Brierley said that until recently there had not been much research into the role of the Nav 1.1 channel subtype on the peripheral nervous system.

“Over a long period of time we were able to work out that one particular compound was in the venom that you could isolate, separate out and acted on this Nav 1.1 channel,” he said.

“It gave us a highly specific and highly selective tool to look at its role in pain.”

Many nociceptors or pain sensing nerve fibres use Nav channels to initiate the electrical impulses that signal pain.

Although the study focused on the peripheral nervous system, the findings also pose potential implications for central nervous system diseases such as epilepsy.

The study was a collaboration between the University of Adelaide, Flinders University, South Australian Health and Medical Research Institute (SAHMRI), the University of Queensland, The University of California, John Hopkins University and the Medical College of Wisconsin. It was published in Nature last week.

Source: http://www.theleadsouthaustralia.com.au/