Boswellia Serrata is a plant. The gum resin extract of this plant is considered to have anti-inflammatory properties. It is considered good for inflammation caused by Rheumatoid Arthritis ,Osteoporosis and Ankylosing Spondylitis. In animal studies, these acids have been shown to significantly reduce inflammation in several cases.

According to British Medical Journal "Boswellia extracts showed some promise in treating asthma, rheumatoid arthritis, Crohn’s disease, knee osteoarthritis, and collagenous colitis. However, all the included trials had flaws: the most common limitations were small sample size and incomplete reporting of data". Further British Medical Journal article states that "Adverse effects  of B serrata were minor and were judged as not causally related to the treatment and not markedly different from those noted in the placebo groups". To read more about this article click here.

Boswellia Serrata is used in India to reduce the inflammation usually found amoung race horses. The qualities of Boswellia Serrata was informed by a Doctor who found significant success treating such horses. The drug was taken as prescribed by the doctor. The Hemogram and ESR were examined before taking Boswellia Serrata.
After a period of 2 months hemogram and ESR were again examined. The ESR had infact gone very high. The symptoms of ankylosing spondylitis too had gone high. The Boswellia Serrata was discontinued. I do not know whether it would be helpful in case of arthritis. I would never say that you shouldn't try Boswellic Acid but always keep a good check on your hemogram and ESR.