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Temporal Effects of Almond Skin Polyphenols on Plasma Biomarkers of Redox Status.
Author(s) -
Milbury Paul E.,
Chen ChungYen,
Blumberg Jeffrey B.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a159
Subject(s) - bioavailability , chemistry , catechin , polyphenol , antioxidant , glutathione , glutathione peroxidase , flavonoid , biochemistry , oxidative stress , pharmacology , food science , superoxide dismutase , enzyme , biology
The in vivo antioxidant efficacy of polyphenols such as flavonoids has not been unequivocally established. Similarly, the impact of these compounds on other actions such as enzyme induction and signal transduction have only been suggested by in vitro studies. We examined the temporal responses of plasma oxidative stress and redox status relative to the kinetics of flavonoids in a randomized cross‐over study of 7 healthy adults aged 51–74 y fed an acute dose of 400 mg almond skin polyphenols or placebo. Plasma flavonoids, F2α‐isoprostanes, glutathione peroxidase (GSHPx), reduced (GSH) and oxidized (GSSG) glutathione, and LDL oxidizability were measured over a10 h post feeding period. Almond polyphenols were bioavailable and increased the resistance of LDL to oxidation. Despite marked individual variability in responses, flavonoid intake patterns reflected their sequential absorption from the stomach, small intestine, and the action of gut flora on glycoside forms. Catechin had a bimodal pattern of bioavailability with maximal concentrations at 45 and 120 min. Naringenin reached its Tmax at 180 min. GSH followed a trimodal pattern corresponding with flavonoid bioavailability to plasma. GSHPx activity was associated with the bimodal catechin absorption pattern. Isoprostane patterns were affected by polyphenol‐induced changes in GSH metabolism. Supported by the USDA ARS and Almond Board of California.