Metabolism of dietary procyanidins in rats.
Procyanidins are major dietary polyphenols made of elementary flavan-3-ol (epi)catechin units. They have antioxidant properties and may contribute to health benefits in humans, but little is known about their metabolic fate. We compared here the metabolism of procyanidin dimer B3, trimer C2, and polymer isolated from willow tree catkins to that of catechin monomer in rats. These compounds were administered in the rat diet (0.1%, w/w) for 5 d and their metabolites estimated in 24 h urine. In rats fed procyanidins, neither parent compound nor catechin derivatives could be detected in contrast to animals fed catechin monomer, which excreted large amounts of catechin and its 3'-O-methylated form (25.7 +/- 0.6%). On the other hand, 16 metabolites of microbial origin were detected and identified as phenylvaleric, phenylpropionic, phenylacetic, and benzoic acid derivatives. Their total yields significantly decreased from the catechin monomer (10.6 +/- 1.1%) to the procyanidin dimer (6.5 +/- 0.2%), trimer (0.7 +/- 0.1%), and polymer (0.5 +/- 0.1%). Therefore, the degree of procyanidin polymerization has a major impact on their fate in the body characterized by a poor absorption through the gut barrier and a limited metabolism by the intestinal microflora as compared to catechin. This will have to be considered to explain the health effects of procyanidins. The contribution of their microbial metabolites should also be further investigated.
Gonthier
Marie-Paule
MP
Unité des Maladies Métaboliques et Micronutriments, INRA Theix, Saint-Genès-Champanelle, France.
Donovan
Jennifer L
JL
Texier
Odile
O
Felgines
Catherine
C
Remesy
Christian
C
Scalbert
Augustin
A
D000818:Animals; D019817:Benzoic Acid / Q000378:metabolism; D044946:Biflavonoids; D002392:Catechin / Q000378:metabolism*; D004032:Diet; D008297:Male; D010421:Pentanoic Acids / Q000378:metabolism; D010648:Phenylacetates / Q000378:metabolism; D010666:Phenylpropionates / Q000378:metabolism; D044945:Proanthocyanidins; D051381:Rats; D017208:Rats, Wistar
D044946:Biflavonoids; D010421:Pentanoic Acids; D010648:Phenylacetates; D010666:Phenylpropionates; D044945:Proanthocyanidins; C017674:procyanidin; D002392:Catechin; D019817:Benzoic Acid; C025136:phenylacetic acid; C400347:5-phenylvaleric acid