TY - JOUR
T1 - A Metabolite Profiling Approach to Identify Biomarkers of Flavonoid Intake in Humans
AU - Loke, Wai
AU - Jenner, A.M.
AU - Proudfoot, Julie
AU - Mckinley, Allan
AU - Hodgson, Jonathan
AU - Halliwell, B.
AU - Croft, Kevin
PY - 2009
Y1 - 2009
N2 - Flavonoids are phytochemicals that are widespread in the human diet. Despite limitations in their bioavailability,experimental and epidemiological data suggest health benefits of flavonoid consumption. Valid biomarkers of flavonoidintake may be useful for estimating exposure in a range of settings. However, to date, few useful flavonoid biomarkershave been identified. In this study, we used a metabolite profiling approach to examine the aromatic and phenolic profile ofplasma and urine of healthy men after oral consumption of 200 mg of the pure flavonoids, quercetin, (-)-epicatechin, andepigallocatechin gallate, which represent major flavonoid constituents in the diet. Following enzymatic hydrolysis, 71aromatic compounds were quantified in plasma and urine at 2 and 5 h, respectively, after flavonoid ingestion. Plasmaconcentrations of different aromatic compounds ranged widely, from 0.01 to 10 mmol/L, with variation among volunteers.None of the aromatic compounds was significantly elevated in plasma 2 h after consumption of either flavonoid comparedwith water placebo. This indicates that flavonoid-derived aromatic compounds are not responsible for the acutephysiological effects reported within 2 h in previous human intervention studies involving flavonoids or flavonoid-rich foodconsumption. These effects are more likely due to absorption of the intact flavonoid. Our urine analysis suggested thaturinary 4-ethylphenol, benzoic acid, and 4-ethylbenzoic acid may be potential biomarkers of quercetin intake and 1,3,5-trimethoxybenzene, 4-O-methylgallic acid, 3-O-methylgallic acid, and gallic acid may be potential markers ofepigallocatechin gallate intake. Potential biomarkers of (-)-epicatechin were not identified. These urinary biomarkersmay provide an accurate indication of flavonoid exposure. J. Nutr. 139: 2309–2314, 2009.
AB - Flavonoids are phytochemicals that are widespread in the human diet. Despite limitations in their bioavailability,experimental and epidemiological data suggest health benefits of flavonoid consumption. Valid biomarkers of flavonoidintake may be useful for estimating exposure in a range of settings. However, to date, few useful flavonoid biomarkershave been identified. In this study, we used a metabolite profiling approach to examine the aromatic and phenolic profile ofplasma and urine of healthy men after oral consumption of 200 mg of the pure flavonoids, quercetin, (-)-epicatechin, andepigallocatechin gallate, which represent major flavonoid constituents in the diet. Following enzymatic hydrolysis, 71aromatic compounds were quantified in plasma and urine at 2 and 5 h, respectively, after flavonoid ingestion. Plasmaconcentrations of different aromatic compounds ranged widely, from 0.01 to 10 mmol/L, with variation among volunteers.None of the aromatic compounds was significantly elevated in plasma 2 h after consumption of either flavonoid comparedwith water placebo. This indicates that flavonoid-derived aromatic compounds are not responsible for the acutephysiological effects reported within 2 h in previous human intervention studies involving flavonoids or flavonoid-rich foodconsumption. These effects are more likely due to absorption of the intact flavonoid. Our urine analysis suggested thaturinary 4-ethylphenol, benzoic acid, and 4-ethylbenzoic acid may be potential biomarkers of quercetin intake and 1,3,5-trimethoxybenzene, 4-O-methylgallic acid, 3-O-methylgallic acid, and gallic acid may be potential markers ofepigallocatechin gallate intake. Potential biomarkers of (-)-epicatechin were not identified. These urinary biomarkersmay provide an accurate indication of flavonoid exposure. J. Nutr. 139: 2309–2314, 2009.
U2 - 10.3945/jn.109.113613
DO - 10.3945/jn.109.113613
M3 - Article
C2 - 19812218
SN - 0022-3166
VL - 139
SP - 2309
EP - 2314
JO - The Journal of Nutrition
JF - The Journal of Nutrition
ER -