Non-extractable proanthocyanidins from grapes are a source of bioavailable (epi)catechin and derived metabolites in rats.
Br J Nutr
; 108(2): 290-7, 2012 Jul.
Article
in En
| MEDLINE
| ID: mdl-22142937
ABSTRACT
The non-extractable fraction of many fruit and vegetables contains putatively bioactive polyphenolic compounds that, in most cases, have not been well characterised structurally. Non-extractable proanthocyanidins (NEPA) of a polymeric nature are part of the dietary fibre fraction of food. Using liquid chromatography coupled to a mass spectrometer equipped with an electrospray ionisation chamber and a triple quadrupole mass analyser for tandem analysis (HPLC-ESI-QqQ-MS/MS) techniques, we examine the phenolic metabolites present in urine and faeces from rats 24 h after ingestion of an NEPA-rich fraction. We show that NEPA are partially depolymerised during their transit along the intestinal tract, as evidenced by the presence of (epi)catechin (EC) monomers and dimers in faeces and phase II conjugates of EC in urine. Moreover, NEPA are further metabolised by the intestinal microbiota into smaller metabolites including phenolic acids that are present in urine as both free phenolics and conjugates with glucuronate or sulphate moieties. For the first time, we report evidence that NEPA behave in vivo as a source of phenolics that are released progressively and deliver phenolic species that come into contact with the intestinal walls and are bioavailable for at least 24 h after ingestion.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phenols
/
Dietary Fiber
/
Catechin
/
Dietary Supplements
/
Vitis
/
Proanthocyanidins
/
Fruit
Limits:
Animals
Language:
En
Journal:
Br J Nutr
Year:
2012
Type:
Article
Affiliation country:
Spain