RT Journal Article SR Electronic T1 Boswellic acids: novel, specific, nonredox inhibitors of 5-lipoxygenase. JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 1143 OP 1146 VO 261 IS 3 A1 Safayhi, H A1 Mack, T A1 Sabieraj, J A1 Anazodo, M I A1 Subramanian, L R A1 Ammon, H P YR 1992 UL http://jpet.aspetjournals.org/content/261/3/1143.abstract AB Isomers (alpha- and beta-) of boswellic acids (BAs), 11-keto-beta-BA and their acetyl derivatives were isolated from the gum resin of Boswellia serrata. BA and derivatives concentration dependently decreased the formation of leukotriene B4 from endogenous arachidonic acid in rat peritoneal neutrophils. Among the BAs, acetyl-11-keto-beta-BA induced the most pronounced inhibition of 5-lipoxygenase (5-LO) product formation with an IC50 of 1.5 microM. In contrast to the redox type 5-LO inhibitor nordihydroguaiaretic acid, BA in concentrations up to 400 microM did not impair the cyclooxygenase and 12-lipoxygenase in isolated human platelets and the peroxidation of arachidonic acid by Fe-ascorbate. The data strongly suggest that BAs are specific, nonreducing-type inhibitors of the 5-LO product formation either interacting directly with the 5-LO or blocking its translocation.