Boswellia, also called frankincense, is a gummy resin derived from the Boswellia serrata tree, a large branching tree native to area of India. The resin is extracted from the tree by tapping; the exudate is then purified to create the herbal preparation. Boswellia has been used as a traditional medicine in Ayurvedic medicine for hundreds of years. It contains substances that help to modulate the inflammatory response and also appears be promising as an analgesic.
History of Use
While Boswellia is well-known for its use as a fragrance (in soaps, cosmetics, and incense) it has also been used as a medicine for thousands of years. In the Ayurvedic traditional medicine tradition, frankincense is best known for use in arthritic pain (osteoarthritis, rheumatoid arthritis), bursitis, and tendonitis. But is has also been used for abdominal pain, ulcerative colitis, asthma, hay fever, painful menstruation, and to increase urinary flow.
The active constituents in Boswellia appear to be the pentacyclic triterpenes called boswellic acids, which appear to be non-competitive inhibitor of in neutrophilic granulocytes 5-lipoxygenase, a key enzyme in the production of inflammatory leukotrienes. , Two key boswellic acids possess this anti-5-lipoxygenase activity: 11-keto-β-boswellic acid (KBA) and acetyl-11-keto-β-boswellic acid (AKBA). Studies, however, have shown low serum levels following ingestion bringing in to question how active they are in humans. Other studies have suggested that beta-boswellic acid may be the active constituent that works by inhibiting microsomal prostaglandin E synthase-1 and the serine protease cathepsin G.  Beta-boswellic acid also inhibits NF-kappa-B, another pro-inflammatory molecule, and it also may have an impact on the complement system.
Other boswellic acids appear to stimulate the immune system by increase lymphocyte proliferation and phagocytosis.
There are questions as to whether boswellic acids can be used individually as medicine, or the whole extract is better. Most extracts are standardized to contain 37-65 percent boswellic acids.
A general dosing guideline suggests taking from 100-400 milligrams a day. The Arthritis Foundation, suggests a dose of 300 mg to 400 mg three times per day.
The best studied condition for the use of Boswellia is osteoarthritis and it has shown some promise as an effective treatment for the condition. Other studies have looked into using Boswellia in ulcerative colitis and asthma.
Osteoarthritis is the best studied in conjunction with Boswellia. In general, supplementing with Boswellia has been shown to reduce pain (by up to 30-60 percent), increase walking distances, increase knee flexion, and increase overall activity levels. Rheumatoid arthritis has been less studied and lacking positive results.
- In a small (n=30) randomized, double blind, crossover study patients with osteoarthritis (OA) of the knee assigned to either the placebo group or the Boswellia extract group (333 milligram dose containing 65% organic acids or minimum 40% total Boswellic Acids ). During the active treatment, patients reported significant decreases in knee pain, increase knee flexion, and increased walking distance. Knee joint swelling also decreased although there were no radiological changes.
- Boswellia extract (333 milligrams) was compared in a randomized, open-label trial versus 10 milligrams valdecoxib (a selective COX-2 inhibitor). Patients (n-66) were randomly assigned to one of the two treatment groups for six months of treatment. The Boswellia group reported significant decreases in morning stiffness and decreased difficulty performing daily activities following 2 months of treatment that extended one month following treatment. The valdecoxib group demonstrated quicker improvements (1 month), but the improvements didn’t last following discontinuation of therapy. 
- A 30 percent 3-O-acetyl-11-keto-beta-boswellic acid (AKBA) extract was examined in a 90-day, double-blind, placebo controlled study of patients (n=75) with osteoarthritis (OA) of the knee. Patients were randomized into one of three groups; 100 milligram AKBA extract (n=25), 250 milligram AKBA extract (n=25), or placebo(n=25). Both doses of AKBA conferred clinically significant improvements in pain scores and physical function, the 250 milligram group reported benefits as early as 7 days following treatment. A drop in cartilage degrading enzyme matrix metalloproteinase-3 was also noted.
While Boswellia has not been extensively studied for asthma, one small preliminary double-blind, placebo-controlled study reported a 70 percent decrease in symptoms (dyspnea, rhonchi, number of attacks) as well as subjective improvements (an increase in FEV subset1, FVC and PEFR and a decrease in eosinophilic count and ESR) with supplementation (300 milligrams/TID).
Boswellia has shown some promise in ulcerative colitis.
- Patients with Crohn’s disease were randomly assigned to either Boswellia (H15) or mesalazine (standard treatment). Reductions in the Crohn Disease Activity Index (CDAI) were present for both groups but did not reach statistical significance between groups suggesting that Boswellia is equally as effective as the standard treatment, but not superior.
- Patients (n=26) with histologically proven collagenous colitis were randomized to receive either a standardized Boswellia extract (400mg/3 times daily) for six weeks or placebo. Clinical remission occurred in 63.6 percent of those treated with Boswellia, compared to 26.7 percent in placebo group (p=0.25).
Boswellia is thought to interact with other anti-inflammatories, but no interactions have been reported.
There is some suggestions that Boswellia may be and emmenagogue and abortifacient and should be avoided in women who have increased menstrual flow or any woman thinking of getting pregnant or who are pregnant.
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