A tropical worm could one day help to relieve the pain of millions of people with rheumatoid arthritis and similar diseases.
The nematode lives off humans
Researchers in Scotland have found that secretions from a parasitic worm, called a filarial nematode, have an anti-inflammatory effect.
They believe the discovery could help people with autoimmune diseases - conditions where the body's own immune system attacks itself for no apparent reason.
The worm lives off humans and is carried by hundreds of millions of people in the tropics, where the incidence of autoimmune disease is much lower.
Researchers at the University of Strathclyde say the worm secretes a molecule called ES-62.
This molecule enables the worm to survive inside the host but does not appear to have any visible impact on humans except to reduce inflammation.
Professor William Harnett, who has led the study, described the finding as exciting.
"This discovery is very exciting and it may help explain an observation that has puzzled scientists and clinicians for decades: the reduced incidence of autoimmune diseases in areas of high nematode worm transmission.
"It still seems ironic, however, that a parasitic worm, which lives off humans may also provide a means to relieve suffering for millions of people."
The scientists hope they can harness their research to create a new drug, which could relieve pain for millions around the world.
"We hope to produce a derivative of the worm's anti-inflammatory molecule and use it as the basis for a drug," Professor Harnett said.
"We are in an ideal position to see this research right through to clinical trial stage, where we can really make a difference to patients' lives."
The scientists will collaborate with experts from the University of Glasgow on the project.
Professor Iain McInnes of Glasgow University said the study would benefit patients.
"We desperately need new treatments for autoimmune diseases. Existing treatments, even the newest, most innovative ones, have limitations.
"They do not work for everybody and the side-effects can be debilitating in themselves.
"The prospect of treating painful inflammatory diseases with a drug that doesn't completely suppress the patient's immune system is a major medical breakthrough."
The scientists have received funding from Scotland's Proof of Concept fund, which aims to support technological innovation.