Anti-tumor and anti-carcinogenic activities of triterpenoid, β-boswellic acid

Boswellin (BE), a methanol extract of the gum resin exudate of Boswellia serrata, contains naturally occurring triterpenoids, beta -boswellic acid and its structural related derivatives, has been used as a traditional medicine for the treatment of inflammatory and arthritic diseases. Topical application of BE to the backs of mice markedly inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced increases in skin inflammation, epidermal proliferation, the number of epidermal cell layers, and tumor promotion in 7,12-dimethylbenz[a]anthracene (DMBA)-initiated mice. Feeding 0.2% of BE in the diet to CF-1 mice for 10-24 weeks reduced the accumulation of parametrial fat pad weight under the abdomen, and inhibited azoxymethane (AOM)-induced formation of aberrant crypt foci (ACF) by 46%. Addition of pure beta -boswellic acid, 3-O-acetyl-beta -boswellic acid, 11-keto-beta -boswellic acid or 3-O-acetyl-11-keto-beta -boswellic acid (Fig. 1)to human leukemia HL-60 cell culture inhibited DNA synthesis in HL-60 cells in a dose-dependent manner with IC50 values ranging from 0.6 to 7.1 muM These results indicate that beta -boswellic acid and its derivatives (the major constituents of Boswellin) have anti-carcinogenic, anti-tumor, and anti-hyperlipidemic activities.