Sheep in battle against human Osteoarthritis

Osteoarthritis is crippling thousands of Australians each year, but research on sheep at Murdoch may provide encouraging news.

Osteoarthritis affects sheep, dogs and horses the same way it affects people. But animal research into the disease and the development of drugs for dogs, for example, is far more advanced than for humans.

Murdoch researcher Martin Cake sums it up: "If an arthritic old lady has an arthritic old dog, she can take it to the vet and get it fixed but there's little for her."

Mr Cake, a PhD researcher at Murdoch's Division of Veterinary and Biomedical Sciences, has been testing the effects of plant extracts on arthritic sheep. It is part of the international search for a drug to slow or reverse the disease.

Already there are drugs that alleviate the disease in dogs, but clinical trials on humans have not been completed.

"Vets and dog owners would be aware of cartrophen, which has been around for many years and appears to work on the symptoms and even slows the disease," he said.

Early medical research focused on reducing the symptoms of osteoarthritis. Recently researchers have been looking at how certain drugs may stimulate the body to release its own compounds (cytokines) that can arrest the disease and, in some cases, help rebuild the cartilage in joints that has been damaged by the disease.

One such drug, produced by a French company and containing extracts from avocado and soy beans, has been part of the trials on sheep at Murdoch.

"In France people have actually been using (the drug) for years, using oral capsules. But they've never known how it works," said Mr Cake.

He said recently-completed trials, as part of collaborative research with the Institute of Bone and Joint Research at Sydney's Royal North Shore Hospital, showed that the drug induced the production of a cytokine.

In another line of inquiry on the disease, Mr Cake is looking at the role that the joint lining synovium plays in the early onset of osteoarthritis.

"Everybody focuses on the cartilage and not on the underlying bone and synovial cells," he said.

Understanding the changes in the synovium may lead to the early detection of the disease the key to controlling it.

"The problem with osteoarthritis is that it is difficult to test in humans; by the time it is detected it has progressed and already caused damage and pain."

Mr Cake has just started the synovium research, which is part of his PhD at Murdoch.