Determinants of the absorption of the dietary flavonoid quercetin in man

P.C.H. Hollman

Research output: Thesisexternal PhD, WU

Abstract

<p>Oxidation of low density lipoprotein is hypothesised to play an important role in the development of cardiovascular disease. It might be prevented by dietary antioxidants. Quercetin is a dietary flavonoid antioxidant and its intake was inversely associated with cardiovascular disease in some studies. Absorption from the diet is a prerequisite for its potentially beneficial role. This thesis describes studies on the absorption and elimination kinetics of dietary quercetin in humans.<p>To perform these absorption studies, we developed a postcolumn chelation technique for quercetin in HPLC with fluorescence detection using aluminum. Only flavonols that contain a free 3-hydroxyl and 4-keto oxygen binding site formed fluorescent complexes with Al <sup>3+</SUP>. This method improved detectability of quercetin 300 fold as compared to conventional UV detection.<p>We studied the absorption of quercetin in healthy ileostomy subjects so as to avoid <em>losses</em> caused by colonic bacteria. Absorption of quercetin was 52 + 15% for quercetin glucosides found in onions, 17 + 15% for quercetin rutinoside a major quercetin glycoside of tea, and 24 + 9% for free quercetin aglycone.<p>The time course of the plasma quercetin concentration was studied in normal subjects with an intact colon who ingested major dietary sources of quercetin, viz. fried onions containing glucose conjugates of quercetin, apples containing both glucose- and non-glucose quercetin glycosides, and of quercetin-3-rutinoside. Peak plasma levels of quercetin were reached &lt;0.7 h after ingestion of the onions, 2.5 h after the apples, and 9 h after the rutinoside. Bioavailability of both quercetin from apples and of pure quercetin rutinoside was 30% relative to onions. Half-lives of elimination were independent of the quercetin source and were about 24 h.<p>We confirmed that the sugar moiety of the glycoside is an important determinant of absorption in a study with volunteers who ingested solutions of pure quercetin-4'-glucoside and of pure quercetin-3-rutinoside.<p>In conclusion, absorption of dietary quercetin glycosides can be appreciable and depends on the type of sugar moiety of the glycoside. We propose that the sodium-glucose cotransporter is involved in the absorption of quercetin-4'glucoside. Elimination of quercetin from the blood is slow. Repeated consumption of quercetin- containing foods therefore will lead to accumulation of quercetin in plasma.
Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
Supervisors/Advisors
  • Hautvast, J.G.A.J., Promotor
  • Katan, M.B., Promotor
  • Korver, O., Promotor, External person
Award date18 Jun 1997
Place of PublicationS.l.
Publisher
Print ISBNs9789054856917
Publication statusPublished - 1997

Fingerprint

Quercetin
Flavonoids
Glycosides
Onions
Malus
Rutin
Cardiovascular Diseases
Sodium-Glucose Transport Proteins
Antioxidants
Glucose
Flavonols
Ileostomy

Keywords

  • flavones
  • quercetin
  • intestinal absorption

Cite this

Hollman, P.C.H.. / Determinants of the absorption of the dietary flavonoid quercetin in man. S.l. : Hollman, 1997. 187 p.
@phdthesis{a40ac5f431a4459f8fc58c0e79bec21e,
title = "Determinants of the absorption of the dietary flavonoid quercetin in man",
abstract = "Oxidation of low density lipoprotein is hypothesised to play an important role in the development of cardiovascular disease. It might be prevented by dietary antioxidants. Quercetin is a dietary flavonoid antioxidant and its intake was inversely associated with cardiovascular disease in some studies. Absorption from the diet is a prerequisite for its potentially beneficial role. This thesis describes studies on the absorption and elimination kinetics of dietary quercetin in humans.To perform these absorption studies, we developed a postcolumn chelation technique for quercetin in HPLC with fluorescence detection using aluminum. Only flavonols that contain a free 3-hydroxyl and 4-keto oxygen binding site formed fluorescent complexes with Al 3+. This method improved detectability of quercetin 300 fold as compared to conventional UV detection.We studied the absorption of quercetin in healthy ileostomy subjects so as to avoid losses caused by colonic bacteria. Absorption of quercetin was 52 + 15{\%} for quercetin glucosides found in onions, 17 + 15{\%} for quercetin rutinoside a major quercetin glycoside of tea, and 24 + 9{\%} for free quercetin aglycone.The time course of the plasma quercetin concentration was studied in normal subjects with an intact colon who ingested major dietary sources of quercetin, viz. fried onions containing glucose conjugates of quercetin, apples containing both glucose- and non-glucose quercetin glycosides, and of quercetin-3-rutinoside. Peak plasma levels of quercetin were reached <0.7 h after ingestion of the onions, 2.5 h after the apples, and 9 h after the rutinoside. Bioavailability of both quercetin from apples and of pure quercetin rutinoside was 30{\%} relative to onions. Half-lives of elimination were independent of the quercetin source and were about 24 h.We confirmed that the sugar moiety of the glycoside is an important determinant of absorption in a study with volunteers who ingested solutions of pure quercetin-4'-glucoside and of pure quercetin-3-rutinoside.In conclusion, absorption of dietary quercetin glycosides can be appreciable and depends on the type of sugar moiety of the glycoside. We propose that the sodium-glucose cotransporter is involved in the absorption of quercetin-4'glucoside. Elimination of quercetin from the blood is slow. Repeated consumption of quercetin- containing foods therefore will lead to accumulation of quercetin in plasma.",
keywords = "flavonen, quercetine, darmabsorptie, flavones, quercetin, intestinal absorption",
author = "P.C.H. Hollman",
note = "WU thesis 2289 Proefschrift Wageningen",
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Hollman, PCH 1997, 'Determinants of the absorption of the dietary flavonoid quercetin in man', Doctor of Philosophy, S.l..

Determinants of the absorption of the dietary flavonoid quercetin in man. / Hollman, P.C.H.

S.l. : Hollman, 1997. 187 p.

Research output: Thesisexternal PhD, WU

TY - THES

T1 - Determinants of the absorption of the dietary flavonoid quercetin in man

AU - Hollman, P.C.H.

N1 - WU thesis 2289 Proefschrift Wageningen

PY - 1997

Y1 - 1997

N2 - Oxidation of low density lipoprotein is hypothesised to play an important role in the development of cardiovascular disease. It might be prevented by dietary antioxidants. Quercetin is a dietary flavonoid antioxidant and its intake was inversely associated with cardiovascular disease in some studies. Absorption from the diet is a prerequisite for its potentially beneficial role. This thesis describes studies on the absorption and elimination kinetics of dietary quercetin in humans.To perform these absorption studies, we developed a postcolumn chelation technique for quercetin in HPLC with fluorescence detection using aluminum. Only flavonols that contain a free 3-hydroxyl and 4-keto oxygen binding site formed fluorescent complexes with Al 3+. This method improved detectability of quercetin 300 fold as compared to conventional UV detection.We studied the absorption of quercetin in healthy ileostomy subjects so as to avoid losses caused by colonic bacteria. Absorption of quercetin was 52 + 15% for quercetin glucosides found in onions, 17 + 15% for quercetin rutinoside a major quercetin glycoside of tea, and 24 + 9% for free quercetin aglycone.The time course of the plasma quercetin concentration was studied in normal subjects with an intact colon who ingested major dietary sources of quercetin, viz. fried onions containing glucose conjugates of quercetin, apples containing both glucose- and non-glucose quercetin glycosides, and of quercetin-3-rutinoside. Peak plasma levels of quercetin were reached <0.7 h after ingestion of the onions, 2.5 h after the apples, and 9 h after the rutinoside. Bioavailability of both quercetin from apples and of pure quercetin rutinoside was 30% relative to onions. Half-lives of elimination were independent of the quercetin source and were about 24 h.We confirmed that the sugar moiety of the glycoside is an important determinant of absorption in a study with volunteers who ingested solutions of pure quercetin-4'-glucoside and of pure quercetin-3-rutinoside.In conclusion, absorption of dietary quercetin glycosides can be appreciable and depends on the type of sugar moiety of the glycoside. We propose that the sodium-glucose cotransporter is involved in the absorption of quercetin-4'glucoside. Elimination of quercetin from the blood is slow. Repeated consumption of quercetin- containing foods therefore will lead to accumulation of quercetin in plasma.

AB - Oxidation of low density lipoprotein is hypothesised to play an important role in the development of cardiovascular disease. It might be prevented by dietary antioxidants. Quercetin is a dietary flavonoid antioxidant and its intake was inversely associated with cardiovascular disease in some studies. Absorption from the diet is a prerequisite for its potentially beneficial role. This thesis describes studies on the absorption and elimination kinetics of dietary quercetin in humans.To perform these absorption studies, we developed a postcolumn chelation technique for quercetin in HPLC with fluorescence detection using aluminum. Only flavonols that contain a free 3-hydroxyl and 4-keto oxygen binding site formed fluorescent complexes with Al 3+. This method improved detectability of quercetin 300 fold as compared to conventional UV detection.We studied the absorption of quercetin in healthy ileostomy subjects so as to avoid losses caused by colonic bacteria. Absorption of quercetin was 52 + 15% for quercetin glucosides found in onions, 17 + 15% for quercetin rutinoside a major quercetin glycoside of tea, and 24 + 9% for free quercetin aglycone.The time course of the plasma quercetin concentration was studied in normal subjects with an intact colon who ingested major dietary sources of quercetin, viz. fried onions containing glucose conjugates of quercetin, apples containing both glucose- and non-glucose quercetin glycosides, and of quercetin-3-rutinoside. Peak plasma levels of quercetin were reached <0.7 h after ingestion of the onions, 2.5 h after the apples, and 9 h after the rutinoside. Bioavailability of both quercetin from apples and of pure quercetin rutinoside was 30% relative to onions. Half-lives of elimination were independent of the quercetin source and were about 24 h.We confirmed that the sugar moiety of the glycoside is an important determinant of absorption in a study with volunteers who ingested solutions of pure quercetin-4'-glucoside and of pure quercetin-3-rutinoside.In conclusion, absorption of dietary quercetin glycosides can be appreciable and depends on the type of sugar moiety of the glycoside. We propose that the sodium-glucose cotransporter is involved in the absorption of quercetin-4'glucoside. Elimination of quercetin from the blood is slow. Repeated consumption of quercetin- containing foods therefore will lead to accumulation of quercetin in plasma.

KW - flavonen

KW - quercetine

KW - darmabsorptie

KW - flavones

KW - quercetin

KW - intestinal absorption

M3 - external PhD, WU

SN - 9789054856917

PB - Hollman

CY - S.l.

ER -