Novel fluorometric assay for hydroxyl radical prevention capacity using fluorescein as the probe.
A novel fluorometric method has been developed to evaluate hydroxyl radical prevention capacity using fluorescein (FL) as the probe. The hydroxyl radical is generated by a Co(II)-mediated Fenton-like reaction, and the hydroxyl radical formation under the experimental condition is indirectly confirmed by the hydroxylation of p-hydroxybenzoic acid. The fluorescence decay curve of FL is monitored in the absence or presence of antioxidant, the area under the fluorescence decay curve (AUC) is integrated, and the net AUC, which is an index of the hydroxyl radical prevention capacity, is calculated by subtracting the AUC of the blank from that of the antioxidant. Gallic acid is chosen as a reference standard, and the activity of sample is expressed as gallic acid equivalents. The method is rigorously validated through linearity, precision, accuracy, and ruggedness. A wide range of phenolic antioxidants is analyzed, and the hydroxyl radical prevention capacity is mainly due to the metal-chelating capability of the compounds.
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Boxin
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Brunswick Laboratories, 6 Thatcher Lane, Wareham, Massachusetts 02571, USA.
Hampsch-Woodill
Maureen
M
Flanagan
Judith
J
Deemer
Elizabeth K
EK
Prior
Ronald L
RL
Huang
Dejian
D
D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003035:Cobalt / Q000737:chemistry; D019793:Fluorescein; D005456:Fluorescent Dyes; D005707:Gallic Acid; D006861:Hydrogen Peroxide / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry*; D007202:Indicators and Reagents; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
D000975:Antioxidants; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D010636:Phenols; D017665:Hydroxyl Radical; D003035:Cobalt; D005707:Gallic Acid; D006861:Hydrogen Peroxide; D019793:Fluorescein