title: Essential requirement of reduced glutathione (GSH) for the anti-oxidant effect of the flavonoid quercetin.
abstract: We have analyzed the anti- or pro-oxidant effects of the flavonoid quercetin (QU) by evaluating, in U937 cell line, hydrogen peroxide (H(2)O(2)), superoxide anion reduced glutathione (GSH) content, mitochondrial membrane potential, DNA content, phosphatidylserine exposure on the outer face of the plasma membrane and cell viability. Polychromatic flow cytometry was used to evaluate in the same cells several functional parameters. For short periods of treatment QU exerted an anti-oxidant effect (decrease in H(2)O(2) levels), whereas for long periods it showed a pro-oxidant activity (increase in ). In these conditions, GSH content was reduced, and this correlated with a lack of anti-oxidant activity of QU, which in turn could be correlated with proapoptotic activity of this molecule. Thus, QU can exert different effects (anti-/prooxidant) depending on exposure times and oxidative balance, and in particular on stores of GSH.
authors.affiliation: University of Modena and Reggio Emilia School of Medicine, Department of Biomedical Sciences, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Ferraresi
authors.forename: Leonarda
authors.initials: L
authors.lastname: Troiano
authors.forename: Erika
authors.initials: E
authors.lastname: Roat
authors.forename: Enrico
authors.initials: E
authors.lastname: Lugli
authors.forename: Elisa
authors.initials: E
authors.lastname: Nemes
authors.forename: Milena
authors.initials: M
authors.lastname: Nasi
authors.forename: Marcello
authors.initials: M
authors.lastname: Pinti
authors.forename: Maria I Garcia
authors.initials: MI
authors.lastname: Fernandez
authors.forename: Edwin L
authors.initials: EL
authors.lastname: Cooper
authors.forename: Andrea
authors.initials: A
authors.lastname: Cossarizza
mesh_terms: D000975:Antioxidants / Q000378:metabolism* / Q000494:pharmacology*; D002470:Cell Survival; D005419:Flavonoids / Q000737:chemistry; D005434:Flow Cytometry; D016166:Free Radical Scavengers; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D015227:Lipid Peroxidation; D008564:Membrane Potentials; D008928:Mitochondria / Q000473:pathology; D016877:Oxidants / Q000737:chemistry; D018384:Oxidative Stress; D010718:Phosphatidylserines / Q000737:chemistry; D011794:Quercetin / Q000737:chemistry / Q000494:pharmacology*; D013481:Superoxides; D013997:Time Factors; D020298:U937 Cells
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D016166:Free Radical Scavengers; D016877:Oxidants; D010718:Phosphatidylserines; D013481:Superoxides; D011794:Quercetin; D006861:Hydrogen Peroxide; D005978:Glutathione