MECHANISM OF ANTIINFLAMMATORY ACTIONS OF CURCUMINE AND BOSWELLIC ACIDS

Curcumine from Curcuma longa and the gum resin of Boswellia serrata, w hich were demonstrated to act as antiinflammatories in in vivo animal models, were studied in a set of in vitro experiments in order to eluc idate the mechanism of their beneficial effects. Currumine inhibited t he 5-lipoxygenase activity in rat peritoneal neutrophils as well as th e 12-lipoxygenase and the cyclooxygena activities in human platelets. In a cell free peroxidation system curcumine exerted strong antioxidat ive activity. Thus, its effects on the dioxygenases are probably due t o its reducing capacity. Boswellic acids were isolated from the gum re sin of Boswellia serrata and identified as the active principles. Bosw ellic acids inhibited the leukotriene synthesis via 5-lipoxygenase, bu t did not affect the 12-lipoxygenase and the cyclooxygenase activities . Additionally, boswellic acids did not impair the peroxidation of ara chidonic acid by iron and ascorbate. The data suggest that boswellic a cids are specific, non-redox inhibitors of leukotriene synthesis eithe r interacting directly with 5-lipoxygenase or blocking its translocati on.