Antioxidant effect of hydroxytyrosol, a polyphenol from olive oil: scavenging of hydrogen peroxide but not superoxide anion produced by human neutrophils.
Hydroxytyrosol (HT) (also known as dihydroxyphenylethanol (DPE)) is a polyphenol extracted from virgin olive oil. HT is known to exert an antioxidant effect but the mechanism of action and the identity of the reactive oxygen molecule(s) targeted are not known. In this study, we show that HT inhibits luminol-amplified chemiluminescence of human neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP), phorbol myristate acetate (PMA) and opsonized zymosan. This effect was dose-dependent and occurred immediately after the addition of HT. However, HT had no effect on lucigenin-amplified chemiluminescence, suggesting that it does not inhibit NADPH oxidase activation or scavenge superoxide anions. Furthermore, HT inhibited H(2)O(2)-dependent-dichlorofuoroscein (DCFH) fluorescence of activated neutrophils, as measured by flow cytometry. Finally, HT inhibited luminol-amplified chemiluminescence in a cell-free system consisting of H(2)O(2) and HRPO. These results suggest that HT, a polyphenol derived from olive oil, could exert its antioxidant effect by scavenging hydrogen peroxide but not superoxide anion released during the respiratory burst.
O'Dowd
Yvonne
Y
Inserm U479 CHU Xavier Bichat, 16 rue Henri Huchard, 75018 Paris, France.
Driss
Fathi
F
Dang
Pham My-Chan
PM
Elbim
Carole
C
Gougerot-Pocidalo
Marie-Anne
MA
Pasquier
Catherine
C
El-Benna
Jamel
J
D000166:Acridines / Q000494:pharmacology; D000328:Adult; D005419:Flavonoids / Q000494:pharmacology; D005434:Flow Cytometry; D005452:Fluoresceins / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008163:Luminescent Measurements; D008165:Luminol / Q000494:pharmacology; D009504:Neutrophils / Q000378:metabolism*; D000069463:Olive Oil; D010636:Phenols / Q000494:pharmacology; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry*; D059808:Polyphenols; D013481:Superoxides / Q000378:metabolism*
D000166:Acridines; D005419:Flavonoids; D005452:Fluoresceins; D016166:Free Radical Scavengers; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D059808:Polyphenols; C005975:3,4-dihydroxyphenylethanol; D013481:Superoxides; C029569:diacetyldichlorofluorescein; C033472:10,10'-dimethyl-9,9'-biacridinium; D008165:Luminol; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D010626:Phenylethyl Alcohol