Ant venom to provide clues for pain relief: research

SYDNEY, March 3 (Xinhua) -- Researchers from the University of Queensland (UQ) have discovered that Australian bull ants adapt their venom based on their predators, and the findings could bear major implications for the treatment of long-term pain.

The research, published in the Proceedings of the National Academy of Sciences (PNAS) journal on Thursday, showed the Australian bull ant had tailored its venom to target Australia's iconic spiked echidna with ants being their preferred food.

Lead author, Dr. Sam Robinson from UQ Institute for Molecular Bioscience, told Xinhua they extracted the ant toxin and then compared its makeup to a database of animal molecules.

"There's literally millions of other sequences and databases out there... Of all those top hits (for the toxin), the closest thing we could detect was to this hormone in the echidna."

He said this is evidence that the ants had tailored a defense mechanism to deter their prime predator over millions of years.

This molecule matched the sequence of an Epidermal Growth Factor (EGF), a protein found in mammal's tissue and hormones, and that is closely related to the echidna.

"What it tells us about pain is that the receptor that this toxin is targeting or the pathway that it's targeting is important in pain."

He said this could lead to new advances in pain medication, and would allow the development of targeted pain relief as opposed to general painkillers like morphine, which when used for long-term pain, can have harmful side effects and lead to addiction.

Robinson said that EGF-inhibitor drugs had already been applied in anti-cancer therapy.

"It's actually quite important because some of these patients' pain is so bad that they actually stop taking or refuse to take the chemotherapy (because of the pain)."

"So, we think that by studying the toxins in them (plants and animals), we can actually figure out what's causing this side effect from this chemotherapy drug ... at a molecular level."

Robinson said he and his team study a broad range of naturally occurring toxins in order to "think outside of the box" when it comes to tackling pain.

"I'm looking at a whole range of different plants and animals and trying to identify new pain targets. This is just one little branch of it really," he added.