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ANALYSIS OF ANTIOXIDANT POTENTIAL USING A BIOASSAY BASED ON OXIDATION OF 5‐(2 AMINOETHYL)BENZENE‐1,2,4‐TRIOL FOR SCREENING PLANT FOOD EXTRACTS
Author(s) -
YAO YU,
VIEIRA AMANDIO
Publication year - 2007
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/j.1745-4514.2007.00124.x
Subject(s) - antioxidant , chemistry , dopamine , bioassay , oxidative stress , biochemistry , food science , reactive oxygen species , fragaria , biology , botany , neuroscience , genetics
Neurotoxic products including reactive quinones and oxygen species such as H 2 O 2 are generated upon oxidation of 4‐(2‐aminoethyl)‐1,2‐benzenediol (dopamine) and 5‐(2‐aminoethyl)benzene‐1,2,4‐triol (6‐OH dopamine). Moreover, neurotoxicity of 6‐OH dopamine and related oxidative stress may be increased in the presence of cytochrome c (Cytc) that is released from its normal mitochondrial location. A Cytc‐enhanced 6‐OH dopamine oxidation reaction is presented as a model bioassay for identifying possible neuroprotective food antioxidants and their metabolites. A concentration‐dependent effect was observed for Cytc upon 6‐OH dopamine oxidation. Fruit/vegetable extracts, prepared from Fragaria and Pisum, were tested by this assay; a three‐ to fourfold greater antioxidant potency was observed for Fragaria. The results were discussed in terms of the content for antioxidant phytochemicals. In addition, potencies for these dietary antioxidants were compared to those of a related assay based on N,N,N′,N′‐tetramethyl‐1,4‐phenylene‐diamine peroxidation.PRACTICAL APPLICATIONS The bioassay presented herein is intended to be used for screening the antioxidant activities of purified dietary compounds and their in vivo metabolites, as well as crude plant extracts and other food preparations. Examples are provided by the use of fruit and vegetable extracts; and these activities arecompared with those of purified phytochemicals. Because of the potential relevance of this assay to some neurological disorders and mitochondrial dysfunctions, phytochemicals and food extracts with strong protective activities in this initial screen may be good candidates for further analyses (biochemical, cellular and animal experiments) related to such disorders e.g., related to dopaminergic neurodegeneration as discussed below.