Bioavailable Blueberry-Derived Phenolic Acids at Physiological Concentrations Enhance Nrf2-Regulated Antioxidant Responses in Human Vascular Endothelial Cells.
Mol Nutr Food Res. 2017 Dec 26. Epub 2017 Dec 26. PMID: 29278300
Jeffry S Tang
SCOPE: Blueberry consumption is believed to confer a cardiovascular health advantage, but the active compounds and effects require characterization. This study aimed to identify the polyphenol metabolites in plasma after blueberry juice intake and determine their bioactivity on endothelial cells.
METHODS AND RESULTS: Three healthy individuals were recruited to obtain profiles of bioavailable plasma polyphenol metabolites following intake of blueberry juice. Of 33 phenolic compounds screened, 12 aglycone phenolic acids were detected and their maximum plasma concentrations and circulation time determined. Using this information, the effect of three physiologically-relevant mixtures of blueberry-derived phenolic acids were investigated for their ability to induce Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2)-nuclear translocation and downstream gene expression in human endothelial cells. Pre-treatment with the phenolic acids for 18 h resulted in a significant up-regulation of the Nrf2-regulated antioxidant response proteins heme oxygenase 1 (HO-1) and glutamate-cysteine ligase modifier subunit (GCLM), following 6 h exposure to 2.5μM H2 O2 .
CONCLUSION: Physiologically-relevant concentrations of blueberry-derived aglycone phenolic acids can induce Nrf2-regulated antioxidant response proteins in vascular endothelial cells in response to lowμM concentrations of H2 O2 . Our results represent an advance over previous studies that have used single compounds or high concentrations in cell-based investigations. This article is protected by copyright. All rights reserved.