Procyanidin Dimers A1, A2, and B2 Are Absorbed without Conjugation or Methylation from the Small Intestine of Rats1–3

M.M. Appeldoorn, J.P. Vincken, H. Gruppen, P.C.H. Hollman

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Abstract

Intervention studies with procyanidin (PC)-rich extracts and products such as cocoa and wine suggest protective effects of PC against cardiovascular diseases. However, there is no consensus on the absorption and metabolism of PC dimers. Interestingly, nothing is known about the absorption of A-type PC. In this study, the absorption and metabolism of purified PC dimers A1 [epicatechin-(2-O-7, 4–8)-catechin], A2 [epicatechin-(2-O-7, 4–8)-epicatechin], and B2 [epicatechin-(4–8)-epicatechin], A-type trimers, a mixture of A1, B2, and a tetrameric A-type, and monomeric epicatechin were compared by in situ perfusion of the small intestine of rats for 0–30 min. The rats had their bile duct, portal vein, and small intestine cannulated. Unmodified and methylated metabolites were distinguished from their conjugates by differential ß-glucuronidase treatment. A1 and A2 dimers were absorbed from the small intestine of rats and they were better absorbed than dimer B2. Absorption of the A-type dimers was only 5–10% of that of monomeric epicatechin. Dimers were not conjugated or methylated in contrast to epicatechin, which was partly methylated and 100% conjugated. A-type trimers were not absorbed. Furthermore, the presence of tetrameric PC enhanced the absorption of B2 but not that of A1. Epicatechin, methylated epicatechin, and their conjugates were not found as metabolites of the PC tested. In conclusion, dimers A1, A2, and B2 are slightly absorbed but are not conjugated or methylated, thus conserving their biological activity after absorption. Because PC contents of foods are relatively high, dimers may contribute to systemic effects of PC.
Original languageEnglish
Pages (from-to)1469-1473
JournalThe Journal of Nutrition
Volume139
Issue number8
DOIs
Publication statusPublished - 2009

Fingerprint

Catechin
varespladib methyl
Methylation
Small Intestine
procyanidin A1
procyanidin
Glucuronidase
Wine
Portal Vein
Bile Ducts
Cardiovascular Diseases
Perfusion
Food

Keywords

  • flavanol-rich cocoa
  • (-)-epicatechin metabolites
  • bioavailability
  • polyphenols
  • humans
  • plasma
  • absorption
  • epicatechin-(4-beta-8)-epicatechin
  • identification
  • consumption

Cite this

@article{8789dffa2dce4e6a93511118507feb46,
title = "Procyanidin Dimers A1, A2, and B2 Are Absorbed without Conjugation or Methylation from the Small Intestine of Rats1–3",
abstract = "Intervention studies with procyanidin (PC)-rich extracts and products such as cocoa and wine suggest protective effects of PC against cardiovascular diseases. However, there is no consensus on the absorption and metabolism of PC dimers. Interestingly, nothing is known about the absorption of A-type PC. In this study, the absorption and metabolism of purified PC dimers A1 [epicatechin-(2-O-7, 4–8)-catechin], A2 [epicatechin-(2-O-7, 4–8)-epicatechin], and B2 [epicatechin-(4–8)-epicatechin], A-type trimers, a mixture of A1, B2, and a tetrameric A-type, and monomeric epicatechin were compared by in situ perfusion of the small intestine of rats for 0–30 min. The rats had their bile duct, portal vein, and small intestine cannulated. Unmodified and methylated metabolites were distinguished from their conjugates by differential {\ss}-glucuronidase treatment. A1 and A2 dimers were absorbed from the small intestine of rats and they were better absorbed than dimer B2. Absorption of the A-type dimers was only 5–10{\%} of that of monomeric epicatechin. Dimers were not conjugated or methylated in contrast to epicatechin, which was partly methylated and 100{\%} conjugated. A-type trimers were not absorbed. Furthermore, the presence of tetrameric PC enhanced the absorption of B2 but not that of A1. Epicatechin, methylated epicatechin, and their conjugates were not found as metabolites of the PC tested. In conclusion, dimers A1, A2, and B2 are slightly absorbed but are not conjugated or methylated, thus conserving their biological activity after absorption. Because PC contents of foods are relatively high, dimers may contribute to systemic effects of PC.",
keywords = "flavanol-rich cocoa, (-)-epicatechin metabolites, bioavailability, polyphenols, humans, plasma, absorption, epicatechin-(4-beta-8)-epicatechin, identification, consumption",
author = "M.M. Appeldoorn and J.P. Vincken and H. Gruppen and P.C.H. Hollman",
year = "2009",
doi = "10.3945/jn.109.106765",
language = "English",
volume = "139",
pages = "1469--1473",
journal = "The Journal of Nutrition",
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Procyanidin Dimers A1, A2, and B2 Are Absorbed without Conjugation or Methylation from the Small Intestine of Rats1–3. / Appeldoorn, M.M.; Vincken, J.P.; Gruppen, H.; Hollman, P.C.H.

In: The Journal of Nutrition, Vol. 139, No. 8, 2009, p. 1469-1473.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Procyanidin Dimers A1, A2, and B2 Are Absorbed without Conjugation or Methylation from the Small Intestine of Rats1–3

AU - Appeldoorn, M.M.

AU - Vincken, J.P.

AU - Gruppen, H.

AU - Hollman, P.C.H.

PY - 2009

Y1 - 2009

N2 - Intervention studies with procyanidin (PC)-rich extracts and products such as cocoa and wine suggest protective effects of PC against cardiovascular diseases. However, there is no consensus on the absorption and metabolism of PC dimers. Interestingly, nothing is known about the absorption of A-type PC. In this study, the absorption and metabolism of purified PC dimers A1 [epicatechin-(2-O-7, 4–8)-catechin], A2 [epicatechin-(2-O-7, 4–8)-epicatechin], and B2 [epicatechin-(4–8)-epicatechin], A-type trimers, a mixture of A1, B2, and a tetrameric A-type, and monomeric epicatechin were compared by in situ perfusion of the small intestine of rats for 0–30 min. The rats had their bile duct, portal vein, and small intestine cannulated. Unmodified and methylated metabolites were distinguished from their conjugates by differential ß-glucuronidase treatment. A1 and A2 dimers were absorbed from the small intestine of rats and they were better absorbed than dimer B2. Absorption of the A-type dimers was only 5–10% of that of monomeric epicatechin. Dimers were not conjugated or methylated in contrast to epicatechin, which was partly methylated and 100% conjugated. A-type trimers were not absorbed. Furthermore, the presence of tetrameric PC enhanced the absorption of B2 but not that of A1. Epicatechin, methylated epicatechin, and their conjugates were not found as metabolites of the PC tested. In conclusion, dimers A1, A2, and B2 are slightly absorbed but are not conjugated or methylated, thus conserving their biological activity after absorption. Because PC contents of foods are relatively high, dimers may contribute to systemic effects of PC.

AB - Intervention studies with procyanidin (PC)-rich extracts and products such as cocoa and wine suggest protective effects of PC against cardiovascular diseases. However, there is no consensus on the absorption and metabolism of PC dimers. Interestingly, nothing is known about the absorption of A-type PC. In this study, the absorption and metabolism of purified PC dimers A1 [epicatechin-(2-O-7, 4–8)-catechin], A2 [epicatechin-(2-O-7, 4–8)-epicatechin], and B2 [epicatechin-(4–8)-epicatechin], A-type trimers, a mixture of A1, B2, and a tetrameric A-type, and monomeric epicatechin were compared by in situ perfusion of the small intestine of rats for 0–30 min. The rats had their bile duct, portal vein, and small intestine cannulated. Unmodified and methylated metabolites were distinguished from their conjugates by differential ß-glucuronidase treatment. A1 and A2 dimers were absorbed from the small intestine of rats and they were better absorbed than dimer B2. Absorption of the A-type dimers was only 5–10% of that of monomeric epicatechin. Dimers were not conjugated or methylated in contrast to epicatechin, which was partly methylated and 100% conjugated. A-type trimers were not absorbed. Furthermore, the presence of tetrameric PC enhanced the absorption of B2 but not that of A1. Epicatechin, methylated epicatechin, and their conjugates were not found as metabolites of the PC tested. In conclusion, dimers A1, A2, and B2 are slightly absorbed but are not conjugated or methylated, thus conserving their biological activity after absorption. Because PC contents of foods are relatively high, dimers may contribute to systemic effects of PC.

KW - flavanol-rich cocoa

KW - (-)-epicatechin metabolites

KW - bioavailability

KW - polyphenols

KW - humans

KW - plasma

KW - absorption

KW - epicatechin-(4-beta-8)-epicatechin

KW - identification

KW - consumption

U2 - 10.3945/jn.109.106765

DO - 10.3945/jn.109.106765

M3 - Article

VL - 139

SP - 1469

EP - 1473

JO - The Journal of Nutrition

JF - The Journal of Nutrition

SN - 0022-3166

IS - 8

ER -