Cytokines, such as IL-1 and oncostatin M (OSM), can induce the expression and release of inflammatory mediators, such as nitric oxide (NO) and prostaglandin E2 (PGE2) from articular cartilage; they can induce the release and activity of matrix metalloproteinase’s (MMP’s), which promote extracellular matrix degradation during both rheumatoid and osteo-arthritis. Identifying potential therapeutics which can alleviate the symptoms associated with arthritis without any toxicity is an on-going pursuit.
Boswellia frereana, a species of Frankincense (indigenous to Somalia) was found to attenuate MMP-9 activity (Blain et al. 2010).The extract comprises ~60% epi-lupeol, with minor amounts of lupeol, lupeol acetate, α- and β-amyrin (< 8% of each). The objective of this study was therefore to investigate the active constituent(s) of B. frereana.
Full depth articular cartilage explants taken from the metacarpo-phalangeal joint of bovine calves, were treated with the cytokines IL-1α (5ng/ml) and OSM (10ng/ml) in the presence or absence of epi-lupeol, lupeol, α- or β-amyrin at 50 μg/ml for up to 28 days. Both epi-lupeol and lupeol attenuated cytokine induced release and expression of NO and PGE2. Epi-lupeol had a greater efficacy than lupeol in attenuating MMP-9 release, activity and gene expression, whilst lupeol attenuated MMP-13 activity and gene expression. α- and β-amyrin were not efficacious in this inflammatory model of cartilage degeneration.
Epi-lupeol may therefore be a useful therapeutic in reducing inflammation-induced MMP-9 activity as observed in arthritis.