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Essential requirement of reduced glutathione (GSH) for the anti-oxidant effect of the flavonoid quercetin

2005; Taylor & Francis; Volume: 39; Issue: 11 Linguagem: Inglês

10.1080/10715760500306935

1071-5762

Roberta Ferraresi, Leonarda Troiano, Erika Roat, Enrico Lugli, Elisa Nemes, Milena Nasi, Marcello Pinti, María García‐Fernández, Edwin L. Cooper, Andrea Cossarizza,

Free Radicals and Antioxidants

We have analyzed the anti- or pro-oxidant effects of the flavonoid quercetin (QU) by evaluating, in U937 cell line, hydrogen peroxide (H2O2), 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 H2O2 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.