Bioavailable Concentrations of Delphinidin and Its Metabolite, Gallic Acid, Induce Antioxidant Protection Associated with Increased Intracellular Glutathione in Cultured Endothelial Cells

Figure 1

(a) Ferric reducing ability of plasma (FRAP) of delphinidin (Del) and gallic acid (GA) in culture medium ( for each phenolic; , 2-factor ANOVA with Bonferroni posttest). (b) Electron paramagnetic resonance spectra of delphinidin samples (1 nM and 100 μM) in tissue culture medium containing 2 mM Tempone-H at time 0 and 30 min. Addition of a superoxide radical (produced by delphinidin) to the EPR-silent spin trap (Tempone-H) forms a persistent adduct (4-oxo-tempo) which is EPR active and displays multiline spectrum characteristic of an unpaired electron in the vicinity of a nucleus. (c) Rate of oxygen-centred free radical production by Del and GA in tissue culture medium. Prooxidant activity: tested compound generated more radicals than tissue culture medium alone. Antioxidant activity: tested compound reduced the amount of free radicals produced by medium alone ( for each phenolic; , 2-factor ANOVA).

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