INHIBITION OF LEUKOCYTE LEUKOTRIENE B-4 PRODUCTION BY AN OLIVE OIL-DERIVED PHENOL IDENTIFIED BY MASS-SPECTROMETRY

We have evaluated the effects of hydroxytyrosol (HT), a potent antioxi dant present in olive oil, on the formation of arachidonic acid 5-lipo xygenase metabolites by leukocytes in vitro. HT, a simple phenolic com pound, extracted from first-pressure oil, was isolated by HPLC and cha racterized by gas chromatography/mass spectrometry. HT inhibited in a dose-related manner the production of leukotriene B-4 (LTB4) by calciu m ionophore-stimulated leukocytes. As expected, similar inhibition was observed for omega-oxidized metabolites of LTB4, namely 20-hydroxy an d 20-carboxy-LTB4. The results disclose a new biological activity of o live oil-derived phenols on leukocyte eicosanoid production. (C) 1997 Elsevier Science Ltd.