A traditional Chinese herb may offer a low-cost treatment option for reducing the pain and inflammation of rheumatoid arthritis. The herb, made from the root of what is known in traditional Chinese medicine as thunder god vine, has been used for relief of the swollen, painful, and inflamed joints characteristic of rheumatoid arthritis (RA). It is approved to treat the disease in China.

Chinese researchers recently found that the herb, Tripterygium wilfordii (TwHF), may reduce symptoms associated with RA, an autoimmune disease most often treated with expensive drugs known as DMARDs.

People receiving TwHF alone did as well as those receiving methotrexate alone. And those who used TwHF and methotrexate together saw an improvement of RA symptoms of at least 50 percent.

The medicinally active compounds in TwHF are called diterpenoids. Made from the skinned root of the thunder god vine, they suppress the inflammatory response characteristic of rheumatoid arthritis, in which the body's own immune system attacks joints.

The 200 people in the study were being treated for active RA at nine general hospitals in China. None had been previously treated with DMARDs.

Patients were divided into three groups: One group received TwHF alone; another, the DMARD methotrexate alone; and a third, TwHF and methotrexate together.

People receiving TwHF alone did as well as those receiving methotrexate alone. And those who used TwHF and methotrexate together saw an improvement of RA symptoms of at least 50 percent.

Researchers plan to follow these patients for two years because the duration of the study was not long enough to determine whether the herb reduces the progression of the disease. And because the study was done in China where smaller doses of the drug are commonly used, further studies are needed determine if a larger dose would have a significantly greater effect on RA symptoms.

The study is published in the Annals of Rheumatic Diseases.