In vitro inhibition of mouse epidermal cell lipoxygenase by flavonoids: structure-activity relationships

Lipoxygenase was extracted from mouse epidermal cells and partially purified by ammonium sulfate precipitation. Using a biological oxygen monitor for activity measurements and linoleic acid as substrate, the effect of a series of flavonoids on lipoxygenase activity was determined. Flavone itself did not inhibit lipoxygenase, but hydroxylated derivatives retaining the double bond in the 2,3 position and having a hydroxyl group in the 3 position (such as quercetin and 3-hydroxy-flavone) were potent lipoxygenase inhibitors compared to flavonoids without those particular functional groups.