New Delhi, Aug. 3: The extract of a herb used for centuries in traditional Indian medicine can reduce symptoms of osteoarthritis, the most common inflammatory joint disease, a group of Indian and American scientists has claimed.

A clinical trial conducted by Siba Raychaudhuri from the University of California, Davis, and her co-workers in India has shown that the extract of the plant, Boswellia serrata, can reduce pain and significantly improve knee joint function.

A number of studies on rats in the past have indicated that the gum resin extracted from Boswellia serrata — also known as Indian Frankincense, or Shallaki — displays anti-inflammatory and anti-arthritic effects. The previous studies on rats have also shown that extracts of the herb at doses up to 3000 times what would be given to humans do not harm the animals.

Raychaudhuri and her colleagues have described their study as the first to evaluate the efficacy of the extract enriched with a form of boswellic acid on osteaoarthritis. They conducted a double-blind, placebo-controlled study — a rigorous clinical trial in which neither doctors nor patients know who’s receiving the drug and who’s receiving a placebo — on 70 patients with mild and moderate arthritis.

The extract led to statistically significant improvements in pain and joint function, in some cases providing relief within seven days, the researchers said, describing their results in the journal Arthritis Research & Therapy.

The study was funded by the research centre of an Indian company involved in the development and export of herbal medical products. Some authors of this study are employees or consultants for the research centre.

“The high incidence of adverse effects associated with currently available medications (for arthritis) has created great interest in the search for an effective and safe alternative treatment,” Raychaudhuri said.

The researchers gave patients either placebo, or 100mg per day, or 250mg per day of the extract over a 90-day period. Patients on the higher dose showed a better response.