Boswellic Acids
March 6th, 2007 by admin
Boswellic Acids
The search for safer and more effective anti-inflammatory compounds has resulted in a growing interest in a time-tested botanical well recognized in Ayurveda materia medica. Boswellia serrata is a large, branching, deciduous tree, which grows abundantly in the dry, hilly parts of India.
The gum resin exudate of this tree, known in the vernacular as “Salai guggal,” has been used in the Ayurvedic system of medicine for the management of arthritis, respiratory diseases and liver disorders.
The active principles found in the gum resin, specifically a combination of boswellic acids, have emerged as effective nonsteroidal anti-inflammatory compounds (NSAIDs) with broad biological activities yet without NSAIDs characteristic gastrointestinal side effects. Compared experimentally with the anti-inflammatory drug phenylbutazone, boswellic acids did not produce injury to the gastrointestinal mucosa. The most popular NSAID, aspirin, although much better tolerated than its parent compound salicylates, still has serious side effects, e.g. gastrointestinal irritation and bleeding, that limit its long-term use. In addition, aspirin is contraindicated in patients who have experienced asthma, urticaria (in general allergic reactions), and should be administered with caution in children and teenagers due to the risk of Reye’s syndrome.
Super Aspirin Effect
A plausible way to explain boswellic acids as NSAIDs in the treatment of inflammatory conditions is to compare these natural compounds to the mechanism of aspirin without the typical gastrointestinal irritation. Similarly to aspirin, boswellic acids inhibit the pathway leading from arachidonic acid (a derivative of our body’s phospholipids) to its metabolic derivatives called leukotrienes and prostaglandins. An excess of leukotrienes and prostaglandins may be responsible, directly or indirectly, for the classic signs of inflammation; redness (due to dilated vessels), swelling (due to the blood vessels leaking), pain (due to activation of the pain receptors) and increased heat over the affected part of the body. The specific biochemical mechanism of boswellic acids may differ from that of aspirin. Nevertheless, in both instances the mediators of inflammation, leukotrienes or prostaglandins, are being diminished and the inflammation subdued.
Studies designed to determine the anti-inflammatory mechanism of boswellic acids have indicated that their primary mode of action involves the inhibition of 5-lipoxygenase, the key enzyme responsible in the formation of leukotrienes. Additionally, boswellic acids did not impair the peroxidation of arachidonic acid by iron and ascorbate.4 These results suggest that boswellic acids are safe, specific, non-redox inhibitors of leukotriene synthesis and operate through a well defined mechanism.
One of the most interesting anti-inflammatory mechanisms of boswellic acids is their anti-complementary activity. In vitro experiments have shown that boswellic acids prevented a well-known inflammatory “chain-reaction” involving several protein compounds collectively known as “complement”. This is due to inhibition of an enzyme that activates one of the components of complement, C3 convertase. The domino effect of the complement in the course of rheumatoid arthritis (or a similar chronic inflammatory process) leads to a subsequent elevation of the enzymes [e.g. cathepsins, glucuronidase and human leukocyte elastase (HLE)] causing excessive catabolism (wasting) of the joint-forming glycoproteins and glycosaminoglycans. This tissue-destroying process leads to continuously worsening joint disfigurement, pain and limited mobility. As a consequence of complement-mediated tissue destruction there is an increased release of markers (metabolites) of the connective tissue, e.g. hydroxyproline, hexosamine and uronic acid. Boswellic acids have been found to decrease the levels of tissue destructive enzymes and levels of urinary hydroxyproline, hexosamine and uronic acid in the acute and chronic phases of experimental arthritis.
Analysis of boswellic acids shows that there are four major b-boswellic acids involved in the inhibition of 5-lipoxygenase and related anti-inflammatory events. These are: b -Boswellic Acid, Acetyl-b-Boswellic Acid, 11-keto-b-Boswellic Acid, Acetyl-11-keto-b-Boswellic, listed here in the order of increasing anti-inflammatory properties.
Clinical Usefulness of Boswellic Acids
Boswellic acids have been found effective in alleviation of rheumatoid arthritis (RA) and osteoarthritis (OA).2 A standardized extract of boswellic acids (200 mg tid) was evaluated in a four week double blind, cross-over trial in 30 patients suffering from RA. The mean arthritic score (sum of symptoms) and the biochemical index of inflammation in the group receiving boswellic acids came down significantly after the treatment. However, when the placebo was substituted (crossover), the subjective and objective indices of arthritis rose again.
In another 20-patient, double-blind, crossover study, a boswellia gum resin extract (200 mg tid) combined in an herbomineral formula was evaluated in the treatment of RA and separately in OA. Active and placebo treatments were given for a period of three months. After a washout period of two weeks the regimens were crossed-over. The three month active therapy resulted in a significant decrease in severity of pain, morning stiffness, improved joint mobility score, grip strength score and the overall disability score compared to the placebo group. The biochemical index of inflammation was also significantly improved due to the treatment.
Ulcerative colitis is an example of a chronic inflammatory process in the bowel, which may be caused and/or aggravated by excessive leukotriene production. Effects of Boswellia serrata gum resin (350 mg thrice daily for six weeks) vs. the NSAID sulfasalazine was studied in patients with ulcerative colitis. The tested parameters, including stool properties, histolopathology of rectal biopsies, and blood biochemistry improved after treatment with the gum resin. As a result of the treatment 82 percent of patients went into remission, as compared to a 75 percent remission rate obtained with sulfasalazine.
Boswellic acids were also tested in the management of asthma, since a new generation of anti-asthmatic drugs is based on the premise of being leukotriene inhibitors. In a double blind, placebo-controlled study 40 patients with a several years’ history of bronchial asthma were treated with 300 mg tid of boswellia gum resin for a period of six weeks. Seventy percent of the patients responded to the treatment as evidenced by a reduction in dyspnea, ronchi, and number of attacks, improvement in lung tests and blood biochemistry. Only 27 percent of the patients receiving placebo showed clinical improvement.
It should be noted that the potential of boswellic acids as a NSAID can only be fulfilled with proper standardization of the gum resin extract. Boswellin brand boswellic acids have used HPLC methods of analysis to standardize and validate the extract for the four main beta boswellic acids. Boswellin is standardized for a minimum 70% total organic acids, and no less than 25% of boswellic acids. This precise method of standardization is particularly important in view of the emerging importance of boswellic acids in health conditions ranging from minor to chronic inflammation requiring prolonged administration of a safe and predictable compound.
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