Boswellia serrata is a medium to large deciduous tree native to India and the Punjab region.
Cuts in the tree harvest a resin containing penta-cyclic sesquiterpenes called beta-boswellic acids including -boswellic acid, acetyl-β-boswellic acid, 11-keto-β-boswellic acid, and acetyl-11-keto-β-boswellic acid ( AKBA).
In vitro studies and animal models show that boswellic acids inhibit the synthesis of the pro-inflammatory enzyme, 5-lipoxygenase (5-LO). Compounds from other plants can also block this enzyme, but they do so in a more general way, as an antioxidant, while boswellic acids have been shown to be a specific inhibitor of 5-LO. 5-LO generates inflammatory leukotrienes, which trigger inflammation by promoting free radical damage and migration of inflammation-producing cells to the inflamed body area. Boswellic acids were therefore shown to be specific, non-redox inhibitors of leukotriene synthesis, which either interact directly with 5-LO or block its translocation. Of the four boswellic acids, 3-acetyl-11-keto-β-boswellic acid (AKBA) is the most potent inhibitor of 5-LO.
Unlike non-steroidal anti-inflammatory drugs (NSAIDs), which are known to disrupt glycosaminoglycan synthesis, accelerating articular damage in arthritis, boswellic acids have been shown to significantly reduce this breakdown of glycosaminoglycans. Indeed, in vivo studies on the effect of Boswellia extract and ketoprofen (an NSAID) on glycosaminoglycan metabolism showed that Boswellia inhibits the breakdown of glycosaminoglycans (an important constituent of collagen-rich tissues, such as cartilage, intervertebral discs, trachea, bones, connective tissue, vessel walls and of the synovial joint fluid) significantly decreased compared to controls, while ketoprofen caused a reduction in total tissue glycosaminoglycan content!
Boswellic acids have also been observed to inhibit leukocyte elastase (HLE), which may be involved in the pathogenesis of emphysema. HLE is a serine protease, which injures the tissues, which in turn triggers the inflammatory process. This dual inhibitory effect on the inflammatory process is unique to boswellic acids.
Clinical studies (double-blind, placebo controlled) of Boswellia extracts have shown that symptoms improve in patients with osteoarthritis and rheumatoid arthritis and that Boswellia acids reduce pain and significantly improve knee joint functions and in some cases provide relief within seven days.