Journal ArticleDOI
Development and validation of an improved oxygen radical absorbance capacity assay using fluorescein as the fluorescent probe.
Reads0
Chats0
TLDR
The improved ORAC(FL) assay provides a direct measure of hydrophilic chain-breaking antioxidant capacity against peroxyl radical and demonstrates that fluorescein (FL) is superior to B-phycoerythrin.Abstract:
An improved method of oxygen radical absorbance capacity (ORAC) assay has been developed and validated using fluorescein (3‘,6‘-dihydroxyspiro[isobenzofuran-1[3H],9‘[9H]-xanthen]-3-one) as the fluorescent probe. Our results demonstrate that fluorescein (FL) is superior to B-phycoerythrin. The oxidized FL products induced by peroxyl radical were identified by LC/MS, and the reaction mechanism was determined to follow a classic hydrogen atom transfer mechanism. In addition, methodological and mechanistic comparison of ORACFL with other widely used methods was discussed. It is concluded that, unlike other popular methods, the improved ORACFL assay provides a direct measure of hydrophilic chain-breaking antioxidant capacity against peroxyl radical. Keywords: Fluorescein; ORAC; TEAC; FRAP; chain-breaking antioxidant; free radical; hydrogen atom transfer; single electron transferread more
Citations
More filters
Journal ArticleDOI
Standardized Methods for the Determination of Antioxidant Capacity and Phenolics in Foods and Dietary Supplements
TL;DR: Methods available for the measurement of antioxidant capacity are reviewed, presenting the general chemistry underlying the assays, the types of molecules detected, and the most important advantages and shortcomings of each method.
Journal ArticleDOI
Comparison of ABTS, DPPH, FRAP, and ORAC assays for estimating antioxidant activity from guava fruit extracts
TL;DR: Guava fruit extracts were analyzed for antioxidant activity measured in methanol extract and dichloromethane extract (AOAD), ascorbic acid, total phenolics, and total carotenoids contents.
Journal ArticleDOI
Lipophilic and hydrophilic antioxidant capacities of common foods in the United States
Xianli Wu,Gary R. Beecher,Joanne M. Holden,David B. Haytowitz,Susan E. Gebhardt,Ronald L. Prior +5 more
TL;DR: The data demonstrated that processing can have significant effects on ORAC(FL).
Journal ArticleDOI
Fluorescence probes used for detection of reactive oxygen species
TL;DR: The main goal of the present paper is to review the fluorescence methodologies that have been used for detecting ROS in biological and non-biological media.
Journal ArticleDOI
Assays for hydrophilic and lipophilic antioxidant capacity (oxygen radical absorbance capacity (ORAC(FL))) of plasma and other biological and food samples.
Ronald L. Prior,Ha Hoang,Liwei Gu,Xianli Wu,Mara Bacchiocca,Luke R Howard,Maureen Hampsch-Woodill,Dejian Huang,Boxin Ou,Robert A. Jacob +9 more
TL;DR: These methods provide, for the first time, the ability to obtain a measure of "total antioxidant capacity" in the protein free plasma, using the same peroxyl radical generator for both lipophilic and hydrophilic antioxidants.
References
More filters
Journal ArticleDOI
The ferric reducing ability of plasma (FRAP) as a measure of 'antioxidant power' : the FRAP assay
TL;DR: The FRAP assay offers a putative index of antioxidant, or reducing, potential of biological fluids within the technological reach of every laboratory and researcher interested in oxidative stress and its effects.
Journal ArticleDOI
A Novel Method for Measuring Antioxidant Capacity and its Application to Monitoring the Antioxidant Status in Premature Neonates
Nicholas J. Miller,Catherine Rice-Evans,Michael J. Davies,Vimala Gopinathan,Anthony D Milner +4 more
TL;DR: The method has been applied to investigate the total plasma antioxidant capacity of neonates and how this may be compromised in prematurity, and an antioxidant ranking was established based on their reactivity relative to a 1.0 mmol/l Trolox standard.
Journal ArticleDOI
Antioxidant activity of dietary polyphenols as determined by a modified ferric reducing/antioxidant power assay
TL;DR: The antioxidant (AO) activity of polyphenols (PPs) was determined for the first time using a modified FRAP (ferric reducing/antioxidant power) assay and polyphenol's AO efficiency seemed to depend on the extent of hydroxylation and conjugation.
Journal ArticleDOI
DNA damage by oxygen-derived species Its mechanism and measurement in mammalian systems
Barry Halliwell,Okezie I. Aruoma +1 more
TL;DR: Observation of the role of different oxygen‐derived species in DNA cleavage reactions has been used to determine the extent of oxidative damage to DNA in vivo and to investigate the mechanism of DNA damage by ionizing radiation and chemical carcinogens.
Journal ArticleDOI
Fluorescent Indicators for Imaging Nitric Oxide Production
Hirotatsu Kojima,Yasuteru Urano,Kazuya Kikuchi,Tsunehiko Higuchi,Yasunobu Hirata,Tetsuo Nagano +5 more
TL;DR: Monitoring with a fluorescence microscope should allow direct identification of intracellular production and location of NO.