April 15 (Bloomberg) -- A centuries-old Chinese medical herb known as “thunder god vine” eased the pain and swelling of rheumatoid arthritis as effectively as the commonly prescribed methotrexate, a study showed.
In a trial of 207 patients in China, those who took extracts of the herb showed slightly more improvement than those on methotrexate alone; combining the two boosted efficacy significantly over methotrexate alone. The study appears in the Annals of the Rheumatic Diseases published by BMJ, formerly known as the British Medical Journal.
While traditional Chinese medicine has been practiced for hundreds of years, research into its benefits compared with today’s standard therapies has been limited. Thunder god vine could become a new approach to treating rheumatoid arthritis because not all patients respond to methotrexate and modern biologic treatments, such as Amgen Inc.’s Enbrel, are expensive, the researchers wrote in the report.
“While the herb has been used to treat rheumatoid arthritis in China for many centuries, there wasn’t clinical evidence of its efficacy compared with current standard medical treatments,” said lead author Xuan Zhang, a doctor at the Peking Union Medical College Hospital’s Department of Rheumatology. “The results were very clear because on many indicators it performed slightly better than methotrexate.”
The researchers used a standard measurement based on a 50 percent improvement in the number of tender or swollen joints, along with criteria including pain and disability. The proportion of those achieving the standard after 24 weeks of the trial was 77 percent among those treated with both drugs, 55 percent among those on the herbal extract, and 46.5 percent for those on methotrexate.
There was little difference between the frequency or type of side effects in the three groups, although the number of women who developed irregular periods was slightly higher in those treated with the extract, identified by the name Tripterygium wilfordii Hook F, according to the report.
Extracts from the herb had been found in the 1980s to have an antifertility effect, although other studies showed that the effects were usually reversible and more common in women entering menopause, the authors wrote.
Doctors in China tend to recommend the herbal extract, usually taken in capsule form, as mainly suitable for older patients above the age of 50, Zhang, a professor of medicine at the teaching hospital in Beijing, said in a telephone interview. That is also the same patient group that tends to get afflicted with joint pain, he said.
Thunder god vine extract has also been investigated for its potential to treat autoimmune diseases and some cancers. A drug made from the plant wiped out pancreatic tumors in mice, researchers at the University of Minnesota’s Masonic Cancer Center said in a study published in October 2012.
Tripterygium wilfordii Hook F may be an affordable alternative treatment for rheumatoid arthritis, researchers said.
A month’s worth of the herbal extract costs about 80 yuan ($12.90) a month, while treatments with methotrexate, which has to be used in combination with biological or chemical reagents, costs at least three times more, said Peking Union’s Zhang. Amgen Inc.’s Enbrel, which is usually injected weekly, costs $3,221 per prescription and Abbvie Inc.’s Humira, which is usually injected every other week, costs about $3,650 per prescription, according to data compiled by Bloomberg.
“This would have significance for how we should consider and study fundamental treatments for rheumatoid arthritis in the future,” he said. The research group is continuing to study the three treatment groups beyond 24 weeks for the longer term effects, Zhang said.
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