Researchers have found that a component in the scorpion venom can reduce the severity of rheumatoid arthritis and lead to improved treatment for the autoimmune disorder.

"Rheumatoid arthritis is an autoimmune disease -- one in which the immune system attacks its own body. In this case, it affects the joints," said Christine Beeton, Associate Professor at the Baylor College of Medicine, in Houston, Texas. In a previous study, the team identified a potassium channel on cells called fibroblast -- like synoviocytes (FLS) of patients with rheumatoid arthritis -- that was very important for the development of the disease. "We wanted to find a way to block the channel to stop the cells damaging the joints," Beeton said.

From the hundreds of different components in the scorpion venom, the team identified one called iberiotoxin and found that it is able to specifically block the FLS potassium channel and reduce the severity of rheumatoid arthritis. When iberiotoxin was administered to rat models of rheumatoid arthritis, they stopped the progression of the disease.

In some cases they reversed the signs of established disease, meaning that the animals had better joint mobility and less inflammation in their joints. In addition, treatment with iberiotoxin did not induce side effects, such as tremors and incontinence, the researchers said in a paper appearing in the Journal of Pharmacology and Experimental Therapeutics.

"It was very exciting to see that iberiotoxin is very specific for the potassium channel in FLS and that it did not seem to affect the channels in other types of cells, which might explain the lack of tremors and incontinence," said Mark Tanner, a graduate student at the varsity. "Although these results are promising, much more research needs to be conducted before we can use scorpion venom components to treat rheumatoid arthritis. We think that this venom component, iberiotoxin, can become the basis for developing a new treatment for rheumatoid arthritis in the future," Beeton said.