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Platelet-mediated metabolism of the common dietary flavonoid, quercetin.

Wright B, Gibson T, Spencer J, Lovegrove JA, Gibbins JM - PLoS ONE (2010)

Bottom Line: Flavonoid metabolites remain in blood for periods of time potentially long enough to allow interactions with cellular components of this tissue.It is well-established that flavonoids are metabolised within the intestine and liver into methylated, sulphated and glucuronidated counterparts, which inhibit platelet function.High performance liquid chromatography (HPLC) and mass spectrometry (MS) showed that quercetin was transformed into a compound with a mass identical to tamarixetin, suggesting that the flavonoid was methylated by catechol-O-methyl transferase (COMT) within platelets.

View Article: PubMed Central - PubMed

Affiliation: Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, United Kingdom. b.wright@rdg.ac.uk

ABSTRACT

Background: Flavonoid metabolites remain in blood for periods of time potentially long enough to allow interactions with cellular components of this tissue. It is well-established that flavonoids are metabolised within the intestine and liver into methylated, sulphated and glucuronidated counterparts, which inhibit platelet function.

Methodology/principal findings: We demonstrate evidence suggesting platelets which contain metabolic enzymes, as an alternative location for flavonoid metabolism. Quercetin and a plasma metabolite of this compound, 4'-O-methyl quercetin (tamarixetin) were shown to gain access to the cytosolic compartment of platelets, using confocal microscopy. High performance liquid chromatography (HPLC) and mass spectrometry (MS) showed that quercetin was transformed into a compound with a mass identical to tamarixetin, suggesting that the flavonoid was methylated by catechol-O-methyl transferase (COMT) within platelets.

Conclusions/significance: Platelets potentially mediate a third phase of flavonoid metabolism, which may impact on the regulation of the function of these cells by metabolites of these dietary compounds.

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Related in: MedlinePlus

The structures of quercetin aglycone and plasma metabolites.Quercetin is part of the flavonol subclass of flavonoids. Metabolites of quercetin include methylated (4′-O-methyl quercetin: tamarixetin), sulphated (quercetin-3′-sulphate) and glucuronidated (quercetin-3-glucuronide) counterparts.
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pone-0009673-g001: The structures of quercetin aglycone and plasma metabolites.Quercetin is part of the flavonol subclass of flavonoids. Metabolites of quercetin include methylated (4′-O-methyl quercetin: tamarixetin), sulphated (quercetin-3′-sulphate) and glucuronidated (quercetin-3-glucuronide) counterparts.

Mentions: Following the ingestion of fruits and vegetables, flavonoids (Figure 1) abundantly present in these dietary sources are metabolised [1]. First pass metabolism in enterocytes lining the wall of the small intestine and subsequent transformations within liver hepatocytes generate O-methylated, glucuronidated and sulphated metabolites (Figure 1) [2]–[9]. It is possible that flavonoid metabolism is a multistep process that occurs in other locations including their main transport system, blood. Plasma transit times of flavonoid metabolites of 30 min-11 h [10], [11] may allow these compounds sufficient time to interact with cellular components of blood. The plasma metabolite of quercetin, 4′-O-methyl quercetin (tamarixetin), has been reported to be taken up by erythrocytes [12], [13], and the ex vivo inhibition of platelet-leukocyte associations following ingestion of cocoa flavonoids [14] suggest interactions of the metabolites of these compounds with leukocytes.


Platelet-mediated metabolism of the common dietary flavonoid, quercetin.

Wright B, Gibson T, Spencer J, Lovegrove JA, Gibbins JM - PLoS ONE (2010)

The structures of quercetin aglycone and plasma metabolites.Quercetin is part of the flavonol subclass of flavonoids. Metabolites of quercetin include methylated (4′-O-methyl quercetin: tamarixetin), sulphated (quercetin-3′-sulphate) and glucuronidated (quercetin-3-glucuronide) counterparts.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2837383&req=5

pone-0009673-g001: The structures of quercetin aglycone and plasma metabolites.Quercetin is part of the flavonol subclass of flavonoids. Metabolites of quercetin include methylated (4′-O-methyl quercetin: tamarixetin), sulphated (quercetin-3′-sulphate) and glucuronidated (quercetin-3-glucuronide) counterparts.
Mentions: Following the ingestion of fruits and vegetables, flavonoids (Figure 1) abundantly present in these dietary sources are metabolised [1]. First pass metabolism in enterocytes lining the wall of the small intestine and subsequent transformations within liver hepatocytes generate O-methylated, glucuronidated and sulphated metabolites (Figure 1) [2]–[9]. It is possible that flavonoid metabolism is a multistep process that occurs in other locations including their main transport system, blood. Plasma transit times of flavonoid metabolites of 30 min-11 h [10], [11] may allow these compounds sufficient time to interact with cellular components of blood. The plasma metabolite of quercetin, 4′-O-methyl quercetin (tamarixetin), has been reported to be taken up by erythrocytes [12], [13], and the ex vivo inhibition of platelet-leukocyte associations following ingestion of cocoa flavonoids [14] suggest interactions of the metabolites of these compounds with leukocytes.

Bottom Line: Flavonoid metabolites remain in blood for periods of time potentially long enough to allow interactions with cellular components of this tissue.It is well-established that flavonoids are metabolised within the intestine and liver into methylated, sulphated and glucuronidated counterparts, which inhibit platelet function.High performance liquid chromatography (HPLC) and mass spectrometry (MS) showed that quercetin was transformed into a compound with a mass identical to tamarixetin, suggesting that the flavonoid was methylated by catechol-O-methyl transferase (COMT) within platelets.

View Article: PubMed Central - PubMed

Affiliation: Institute for Cardiovascular and Metabolic Research, School of Biological Sciences, University of Reading, Reading, United Kingdom. b.wright@rdg.ac.uk

ABSTRACT

Background: Flavonoid metabolites remain in blood for periods of time potentially long enough to allow interactions with cellular components of this tissue. It is well-established that flavonoids are metabolised within the intestine and liver into methylated, sulphated and glucuronidated counterparts, which inhibit platelet function.

Methodology/principal findings: We demonstrate evidence suggesting platelets which contain metabolic enzymes, as an alternative location for flavonoid metabolism. Quercetin and a plasma metabolite of this compound, 4'-O-methyl quercetin (tamarixetin) were shown to gain access to the cytosolic compartment of platelets, using confocal microscopy. High performance liquid chromatography (HPLC) and mass spectrometry (MS) showed that quercetin was transformed into a compound with a mass identical to tamarixetin, suggesting that the flavonoid was methylated by catechol-O-methyl transferase (COMT) within platelets.

Conclusions/significance: Platelets potentially mediate a third phase of flavonoid metabolism, which may impact on the regulation of the function of these cells by metabolites of these dietary compounds.

Show MeSH
Related in: MedlinePlus