Une connaissance fine des consommationsen flavonoïdes et de leur devenir dans l’organisme

est indispensable à l’évaluationde leurs effets sur la santé

Augustin SCALBERT

A L I M E N T A T I O N

A G R I C U L T U R E

E N V I R O N N E M E N T

Augustin SCALBERTUnité de Nutrition Humaine

Centre de recherche de Clermont-Ferrand

Flavonoids as antioxidantsFlavonoids as antioxidants

A generic propertyA generic property

OOH

OH O

OH

OH

OH

OOH

OH O

O

OH

OH

LH .L.

Stable radicals !

ControlCatechins

Propyl-gallate

Gallocatechins

Corn oil

+/- Polyphenols

50°C

2-16 days

Lipid hydroperoxides

Flavonoids as antioxidantsFlavonoids as antioxidants

A generic propertyA generic property

F2-isoprostane

Low

F2-isoprostane

Acute effects Longer term effects (1 wk)

Wiswedel et al., 2004, FRBM

� No consistent effect established on the long term

� Markers not yet recognized as independent risk factors for diseases

High

Hodgson et al., 2002, J. Nutr.

About 500 different polyphenols in foodsAbout 500 different polyphenols in foods

Lignans

OOH

OH

OH

CH2OH

O

OOH

OH

OH

OOH

OH O

O

OH

CH2OH

OH

OH

MeO

OMe

OOH

OH

OH O

CH2OH

OOH

OH

OH O

CH2OH

Flavonols

Isoflavones

StilbenesPhenolic acids

Flavonoids Lignans

OH

OH

O

O

OH

OOH

H

HH

OHOH

OH

OH

OOOH

OH

OH

CH2OH

Isoflavones

Catechins

Anthocyanins

Flavanones

Proanthocyanidins

Principales classes de flavonoïdesPrincipales classes de flavonoïdes

OH

O

O

OH

OH

OH

O

O

OH

OH

O

OOH

OH OH + OH

Flavonols Flavones Isoflavones

OH

O

O

OH

O

OH

OH

OH

O

OH

O

OH

O

OH

OH

OH

OH

OH

OH

OH

OH

O+

OH

OH

Flavanones

Flavanols Proanthocyanidines

Anthocyanes

Chemical structure and health outcomesChemical structure and health outcomes

O

OH

O

OH

� Closely related compounds may have different effects on life span

C. elegans

Zou et al., 2007, Mech. Ageing Dev.

Comparison of polyphenols in clinical trialsComparison of polyphenols in clinical trials

OOH

OH

OH

OH

12 healthy male subjects

200 mg polyphenols

Plasma 2 hrs later

OH

Plasma S-nitrosothiols

� Quercetin and epicatechin but not EGCG increase plasma NO

Loke et al., 2008, AJCN

OOH

OH

OH

OH

OH

OH O

Quercetin

Epicatechin

O

O

O

OH

OH

OH

OH

OH

OH

OH

OH

EGCG

Quercetin

Myricetin

GenisteinMorin

Epicatechin

CatechinRutin

Luteolin

Taxifolin

0 2 4

ABTS°+ reduction Cell growth inhibition

0 0,01 0,02

In vitroIn vitro screening for polyphenol bioactivityscreening for polyphenol bioactivity

Taxifolin

NaringeninApigenin

Chrysin

HesperetinKaempferol

Daidzein

GenistinBiochanin A

Hesperidin

FormononetinRice-Evans & Miller, 1996 Kuntz et al., 1999

� Relevance of such studies to compare health effects of polyphenols ?

� In vivo studies essential

Identification des métabolites actifs des polyphénols Identification des métabolites actifs des polyphénols

et de leurs cibles d’actionet de leurs cibles d’action

OOH

OH

HOOC

O O

� Flavonoids ingested

� Absorption in the gut

� Nature and concentration of the metabolites in target tissues

Food

Phytochem.metabolites Target

Health &diseases

OOH

CH2OH

O O

OOH

Une nouvelle base de données sur les Une nouvelle base de données sur les teneurs en polyphénols dans les alimentsteneurs en polyphénols dans les aliments

http://www.phenol-explorer.eu

- 506 phenolic compounds in 454 foods (300 flavonoids)- 1300 scientific publications analysed- 60,000 original content values collected and evaluated

Polyphenols in foods and beveragesPolyphenols in foods and beverages

0 100 200 300

Potato

Tomato

Lettuce

Onion

Apple

Phenolic acids

Flavonols

Catechins

Proanthocyanidins

Anthocyanins

Polyphenols (mg/100 g FW ou 100 ml)

Apple

Cherry

Whole grain wheat flour

Orange juice

Red wine

Coffee

Black tea

Chocolate

Anthocyanins

Flavanones

Others

1500

Source: www.phenol-explorer.eu

Polyphenol intakePolyphenol intake

Anthocyanins

Flavonols

Flavanones

SU.VI.MAX cohort

4,942 men & women

24-hr dietary records (x6)

Phenol-Explorer

OH

OH

O

O

OH

OOH

H

HH

OHOH

OH

OOH

H

HHOH

OH

O

O

OH

OOH

H

HH

OH

OH

OH

O

OOH

203 mg/day

271 mg/day

OOH

OH

OH

OH

OCH

3OH

OHOH

OOH

OH

O

OHO

+

36 mg/day

Hydroxybenzoicacids

Hydroxycinnamicacids

Catechins

Proanthocyanidins

1.8 g/day

OH

OH198 mg/day

OOH

OH

OH

OH

OH

OOH

OH

OH

OH

OH

32 mg/day 31 mg/day

� Flavonoid intake = 0.8 g/day

Non-alcoholizedVegetables

Alcoholizedbeverages

Nuts &beans

Dietary sources of polyphenolsDietary sources of polyphenols

6 %

Oils

Cereals

SU.VI.MAX cohort

4,942 men & women

24-hr dietary records (x6)

Phenol-Explorer

Non-alcoholizedbeverages

Fruits

Cocoa

49 %

11 %

9 %

8 % 6 % 6 %

1.8 g/day

Absorption et métabolisme des Absorption et métabolisme des polyphénolspolyphénols

Polyphénols

Métabolisme

par la microflore

du colon

Absorption au niveau

de l’intestin grêle

Métabolisme

par les tissus

(foie, intestin)

Large variations in flavonoid bioavailabilityLarge variations in flavonoid bioavailability

2 2

Pla

sm

a c

on

c.(

µm

ol /

L )

Pla

sm

a c

on

c.(

µm

ol /

L )

Single dose of 50 mg aglycone equivalentSingle dose of 50 mg aglycone equivalent

GenisteinGenistein (9)(9)

DaidzeinDaidzein (9)(9)

Querc Gluc.Querc Gluc. (7)(7)

RutinRutin (6)(6)

NaringinNaringin (6)(6)

(x)(x) = = Number of studiesNumber of studies0 0

1 1

00 22 44 66 88 1010 1212 1414 1616 1818

Time (hr)Time (hr)

Pla

sm

a c

on

c.(

µm

ol /

L )

Pla

sm

a c

on

c.(

µm

ol /

L )

AnthocyaninsAnthocyanins (6)(6)

EGCgEGCg (11)(11)

HesperidinHesperidin (5)(5)

NaringinNaringin (6)(6)

CatechinsCatechins (12)(12)

Manach et al. (2004) AJCN

Glycosylation influencesGlycosylation influencesthe gut absorption of flavonoidsthe gut absorption of flavonoids

16 healthy subjects

Orange juice

Flavanone concentrations in plasma (µM)

Orange juice

Orange juice+ hesperidinase

� The type of glycosylation is importantNielsen et al., 2006, J. Nutr.

O

O

OHOH O O

OH O

H

OH

O

OH

OH

OMe

OHOH

Me

O

OH

OHOH O O

OH O

H

OH

O

OH

Me

Hesperidinase

Flavonoid polymers are notFlavonoid polymers are notor poorly absorbed in the gutor poorly absorbed in the gut

Rats

Catechin or dimer B3, 0.1 % diet

HPLC-coularray

15co

nce

ntr

atio

n(µ

M)

OHOOH

OH

OH

OOH

OH

OH

OH

OH

0

5

10

3 hrs 9 hrs 3 hrs 9 hrs

Pla

sm

ati

c c

on

ce

ntr

atio

n

OOH

OH

OH

OH

OH

OH

Not detected

� Procyanidin dimer B3 is not absorbedDonovan et al., 2002, BJN

Flavonoids are largely metabolized in the tissuesFlavonoids are largely metabolized in the tissues

Entry

SmallIntestine

Bile

Living Rat

Mesentericblood

Entry

SmallIntestine

Bile

Living Rat

Mesentericblood

OOH

OH

OH

OH

OSO3-

OOH

OH

OH

OH

O OOH

OH

CH2OH

COOH

Catechin metabolites (µM)

Mesenteric plasma Bile

- Free 0 0

- Glucuronide 0.7 0.2

- Glucuronide/sulfate 0 0.8

Donovan et al., 2001, J. Nutr.

ExitExit

OHOH

Biological activity of flavonoid conjugatesBiological activity of flavonoid conjugates

Rat aortic rings

Ach (induces vasorelaxation)

DETCA (inhibits SOD)

+ Quercetin or

Quercetin metabolites

OOH

OH

OOH

OH

O

OH COOH

� Lower vasorelaxation with quercetin metabolites

Lodi F. et al., 2009, Atherosclerosis

OOH

OH O

OH

OH

OH

O OH

OH O

O

CH2OH

Flavonoids are metabolized in the colonFlavonoids are metabolized in the colon

Human colonic microflora 14C-Proanthocyanidin polymers

Autoradiography

GC-MS

OH

CH2

CH2

CH2

CH2

COOH

OH

OH

OOH

OH

OH

OH

OH

OOH

OH

OH

CH2

CH2

COOH

OH

CH2

COOH

CH2

CH2

COOH

CH2

OH

COOH

CH2

CH2

COOH

OOH

OH

OH

OH

OH

OH

OH

OOH

OH

OH

OH

OH

OOH

OH

OH

OH

OH

OOH

OH

OH

OH

OH

Aromatic acids

� Proanthocyanidins are degraded by the microflora

0 4824

Time (hrs)

Déprez et al., 2000, J. Nutr.

Flavonoids and Flavonoids and in vitro in vitro studiesstudies

0,1 1 10 100 1000(Ludwig et al., 2004)

(Choi et al., 2004)(Hernandez-Montes et al., 2006)

(Reiterer et al., 2004)

(Fuchs et al., 2005)(Kim et al., 2005)

(Chao et al., 2005)(Mnjoyan et al., 2003)

(Pal et al., 2003)

Active flavonoid concentrations (µM)

Endothelial cells

Aortic smoothmuscle cells

Nutritional(Pal et al., 2003)(Gouedard et al., 2004)

(Martinez-Florez et al., 2005)

(Mullen et al., 2004)(Sarkar et al., 2004)

(Richard et al., 2005)(Kim et al., 2005)

(Moreno et al., 2003)(Mackenzie et al., 2003)

(Yang et al., 1998)

(Biswas et al., 2005)(Abate et al., 2005)

(Kim et al., 2004)

Hepatocytes

Immune cells

Lung epithelial cellsFibroblastsβ-cells

Nutritionalpolyphenol

concentrations

� Few studies so far published on flavonoid metabolites

� Tested at very high concentrations

Difficult today to predicthealth effects from in vitro studies

Flavonoids Flavonoids –– Intake and bioavailabilityIntake and bioavailability

� Total flavonoid intake 0.8 mg/day

� About 300 different flavonoids in the diet

� Most largely consumed flavonoids

– Anthocyanins– Anthocyanins

– Catechins

– Proanthocyanidins

� Absorption in the gut highly variable

– Glycosides

– Polymers

� Biological properties of metabolites should be studied

INRA Clermont-Ferrand

Puy de Dôme

Claudine MANACH

Vanessa NEVEU

Femke VOSFemke VOS

Jara PEREZ-JIMENEZ

Serge HERCBERT & Pilar GALAN