Preparations from the gum resin of Boswellia serrata have been used as a traditional remedy in Ayurvedic medicine in India for the treatment of inflammatory diseases. Compounds from the gum with genuine antiinflammatory effects are pentacyclic triterpenes of the boswellic acid type. Boswellic acids inhibit the leukotriene biosynthesis in neutrophilic granulocytes by a non-redox, noncompetitive inhibition of 5-lipoxygenase. The effect is triggered by boswellic acids binding to the enzyme. Moreover certain boswellic acids have been described to inhibit elastase in leukocytes, to inhibit proliferation, induce apoptosis and to inhibit topoisomerases of leukoma- and glioma cell lines. A series of chronic inflammatory diseases are thought to be perpetuated by leukotrienes. In clinical trials promising results were observed in patients with rheumatoid arthritis, chronic colitis, ulcerative colitis, Crohn's disease, bronchial asthma und peritumoral brains edemas.