Effects of virgin olive oil phenolics on scavenging of reactive nitrogen species and upon nitrergic neurotransmission.
The major phenolics from the polar fraction of virgin olive oil (caffeic acid, oleuropein, tyrosol and hydroxytyrosol) have well-established antioxidant activities but their effects on reactive nitrogen species and nitrergic neurotransmission have not been fully investigated. The three catechol compounds were active as scavengers of nitric oxide generated spontaneously from the decomposition of sodium nitroprusside (approximately 50% inhibition achieved at 75 microM), and had similar ability to scavenge chemically generated peroxynitrite, as determined by an alpha1-antiproteinase inactivation assay (67.2%-92.4% reduction when added at 1 mM). Tyrosol was less active in these tests, but does not possess the catechol functionality. Despite their ability to interact with chemically prepared nitric oxide, neither oleuropein nor hydroxytyrosol at 5 microM altered NO*-mediated relaxations of the nerve-stimulated rat anococcygeus preparation, but this may be because the nitrergic transmitter is protected from the effects of externally applied scavengers. In conclusion, the phenolics found in virgin olive oil possess ability to scavenge reactive oxygen and nitrogen species that are implicated in human pathologies, but their impact may be restricted to those species present in the extracellular environment.
de la Puerta
R
R
Dpt. Pharmacology, Faculty of Pharmacy, University of Seville, Spain. puerta@fafar.us.es
Martínez Domínguez
M E
ME
Ruíz-Gutíerrez
V
V
Flavill
J A
JA
Hoult
J R
JR
D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002109:Caffeic Acids / Q000302:isolation & purification / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology*; D057888:Iridoid Glucosides; D039823:Iridoids; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000294:innervation; D009431:Neural Conduction / Q000187:drug effects*; D009566:Nitrates / Q000138:chemical synthesis / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009599:Nitroprusside / Q000378:metabolism; D000069463:Olive Oil; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D011714:Pyrans / Q000302:isolation & purification / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D000975:Antioxidants; D002109:Caffeic Acids; D016166:Free Radical Scavengers; D057888:Iridoid Glucosides; D039823:Iridoids; D009566:Nitrates; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D011714:Pyrans; C005975:3,4-dihydroxyphenylethanol; D009599:Nitroprusside; C011867:4-hydroxyphenylethanol; C039642:peroxynitric acid; C002769:oleuropein; D009569:Nitric Oxide; D010626:Phenylethyl Alcohol; C040048:caffeic acid