Boswellia Serrata - A Potential Anti-inflammatory Agent

Boswellia serrata, commonly known as salai guggul, shallaki, and Indian frankincense, is a moderate to large tree of the family Burseraceae, which is native to India, North Africa, and the Middle East. The resin of Boswellia has a rich scent and flavour. Being very popular as incense, Boswellia is used in religious and cultural ceremonies and is also an essential ingredient of Ayurvedic medicines since time immemorial.

The oleo gum-resin of Boswellia serrata contains resin, essential oils, and polysaccharides. The resinous part of Boswellia serrata possesses terpenes and triterpenic acids, including boswellic acid, responsible for inhibiting pro-inflammatory enzymes. Gum-resin extract of Boswellia serrata has been traditionally used in folk medicine for centuries to treat various chronic inflammatory diseases, including osteoarthritis (OA), rheumatoid arthritis (RA), asthma, and inflammatory bowel disease (IBD). The medicinal properties of Boswellia are widely recognized for their antiseptic, antimicrobial, wound healing, and anticancer activities.

Mechanism of Action of Boswellia serrata

Boswellic acid, the major active constituent of Boswellia, contributes to many pharmacological activities. Studies show that anti-inflammatory activity of Boswellia occurs via inhibition of enzyme 5-lipoxygenase and cyclooxygenase-1. Boswellic acid inhibits nuclear transcription factor-kappa B (NF-kappa B) signaling and decreases the key pro-inflammatory cytokine tumour necrosis factor (TNF-alpha). The antiplatelet effects of Boswellia gum resin extracts are attributed to the inhibition of clotting factors Xa and XIa. Boswellic acid also inhibits elastase (an enzyme from the class of proteases (peptidases) that break down proteins) in leukocytes, inhibits proliferation, induces apoptosis, and inhibits topoisomerases in cancer cells. Topoisomerases are crucial enzymes for many fundamental aspects of neural function. Their primary functions are to cleave DNA strands to provide torsional-stress relief or untangle replicating DNA- provide essential cellular controls during replication and transcription.

In addition to its use for arthritis, Boswellia resin is also mentioned in traditional Ayurvedic texts as an effective remedy for diarrhoea, dysentery, fevers (antipyretic), skin ringworm, boils, blood diseases, cardiovascular diseases, mouth sores, bronchitis, asthma, cough, hair loss, hemorrhoids, syphilitic diseases, vaginal discharges, irregular menses, jaundice, and liver stimulation. It is astringent, diaphoretic, and diuretic and acts as an internal and external stimulant. Nowadays, it is strongly recommended as an anti-inflammatory, antiarthritic, analgesic (pain-reliever), antiatherosclerotic (coronary plaque), antihyperlipidemic (controls blood lipids), and hepatoprotective (protects the liver). Some of the medicinal uses of Boswellia are mentioned below:

Boswellia Role in Asthma

Boswellia is vital in treating bronchial asthma as it helps reduce leukotrienes and improves asthma symptoms. These chemicals play a crucial role in allergies, allergic rhinitis, and asthma and cause bronchial muscle contraction, making it difficult to breathe. Boswellic acid blocks the allergic response that causes an asthma reaction in the first place. Due to immune-balancing properties, Boswellia protects from environmental allergens that may lead to asthma. Extract of Boswellia inhibits hypersensitivity reactions by regulating both the humoral and cellular immune systems. It decreases primary antibody synthesis, inhibits proliferation and infiltration of polymorphonuclear leukocyte (a type of white blood cell released during infections, allergic reactions, and asthma), enhances the phagocytotic function of macrophages, and suppresses the inflammation process, one of the critical features in asthma. It also inhibits the release of histamine from mast cells. Boswellia downregulates the synthesis of prostaglandins by inhibiting Cyclooxygenase-1 (COX-1). Studies show that boswellic acid suppresses inflammation in the airways and regulates various inflammatory responses by inhibiting the production of pro-inflammatory cytokines, including Tumour Necrosis Factor-alpha (TNF-α), interleukins (IL-1, IL-2, IL-6, IL-12), and Interferon-gamma (IFN-γ), by suppressing the activation of nuclear factor kappa-light-chain-enhancer of activated B cells NF-κB. Results suggest that Boswellia effectively controls the inflammation process and contraction of airway smooth muscles in asthmatic conditions by inhibiting enzymes required to produce pro-inflammatory mediators and bronchoconstrictors.

Anticancer Properties of Boswellia

Boswellia has antitumor properties and acts in various ways to inhibit cancer growth. Boswellic acids prevent certain enzymes from negatively affecting DNA. Essential oil from Boswellia impairs aggressive skin cancer cells without harming healthy skin cells. Studies show that boswellic acids fight breast cancer cells and limit the spread of leukemia and brain tumor cells. Boswellic acids help reduce mammary density, a risk factor for breast cancer. Boswellia is also effective in suppressing the invasion of pancreatic cancer cells. Boswellia extract helps treat cervical cancer by inducing apoptosis in cancer cells. Research on cytotoxic effects of boswellic acid indicates that it induces p21 expression through a p53-independent pathway and causes apoptosis in glioma and leukemia cells. Boswellic acid inhibits prostate tumour growth by inhibiting vascular endothelial growth factor receptor 2 (VEGFR2)-induced angiogenesis. Boswellia also decreases genitourinary pain in men with prostatitis-like symptoms. Studies suggest Boswellia effectively reduces post-radiotherapy cerebral oedema in brain tumours, including glioblastoma multiforme. A Boswellia-based cream helps prevent skin damage from radiotherapy in breast cancer patients.

Boswellia for Osteoarthritis

Boswellia serrata is used in traditional Ayurvedic medicine to treat joint pain and inflammation. Boswellia improves symptoms of pain and disability in knee osteoarthritis. Studies show that the extract of Boswellia serrata can reduce pain considerably, improve knee-joint functions and prevent the loss of cartilage due to its anti-inflammatory properties. Regular use of Boswellia helps in walking by decreasing knee pain and increasing knee flexion.

Boswellia's Role in Rheumatoid Arthritis

Inflammation around the joints is one of the major symptoms of rheumatoid arthritis (RA). Conventional treatment of rheumatoid arthritis includes non-steroidal anti-inflammatory drugs (NSAIDs) and steroids that mainly focus on reducing inflammation. Boswellia effectively reduces inflammation and helps in the treatment of rheumatoid arthritis. Research suggests that Boswellia interferes with the autoimmune process making it an effective therapy for rheumatoid arthritis. Further research supports the effective anti-inflammatory and immune-balancing properties of Boswellia.

Boswellia Role in Inflammatory Bowel Disease

Due to its anti-inflammatory properties, Boswellia effectively treats inflammatory bowel diseases such as Crohn's disease and ulcerative colitis (UC). Boswellia acts via inhibiting 5-lipoxygenase, thereby decreasing leukotriene biosynthesis and diminishing pro-inflammatory cytokine release. Boswellic acids improve markers of inflammatory bowel disease without causing adverse effects on the surrounding organs. Boswellia is also effective in Crohn's disease for initiating and maintaining remission. Studies show that Boswellia extract decreases Crohn's Disease Activity Index (CDAI), and its effectiveness is comparable to the anti-inflammatory prescription drug mesalamine in treating Crohn's disease.