Absorption, metabolism, and excretion of green tea flavan-3-ols in humans with an ileostomy

Stalmach, A. , Mullen, W., Steiling, H., Williamson, G., Lean, M.E.J. and Crozier, A. (2010) Absorption, metabolism, and excretion of green tea flavan-3-ols in humans with an ileostomy. Molecular Nutrition and Food Research, 54(3), pp. 323-334. (doi: 10.1002/mnfr.200900194)

Full text not currently available from Enlighten.

Publisher's URL: http://dx.doi.org/10.1002/mnfr.200900194

Abstract

Green tea containing 634μ mol of flavan-3-ols was ingested by human subjects with an ileostomy. Ileal fluid, plasma, and urine collected 0-24 h after ingestion were analysed by HPLC-MS. The ileal fluid contained 70% of the ingested flavan-3-ols in the form of parent compounds (33%) and 23 metabolites (37%). The main metabolites effluxed back into the lumen of the small intestine were O-linked sulphates and methyl-sulphates of (epi)catechin and (epi)gallocatechin. Thus, in subjects with a functioning colon substantial quantities of flavan-3-ols would pass from the small to the large intestine. Plasma contained 16 metabolites, principally methylated, sulphated, and glucuronidated conjugates of (epi)catechin and (epi)gallocatechin, exhibiting 101-256 nM peak plasma concentration and the time to reach peak plasma concentration ranging from 0.8 to 2.2 h. Plasma pharmacokinetic profiles were similar to those obtained with healthy subjects, indicating that flavan-3-ol absorption occurs in the small intestine. Ileostomists had earlier plasma time to reach peak plasma concentration values than subjects with an intact colon, indicating the absence of an ileal brake. Urine contained 18 metabolites of (epi)catechin and (epi)gallocatechin in amounts corresponding to 6.8±0.6% of total flavan-3-ol intake. However, excretion of (epi)catechin metabolites was equivalent to 27% of the ingested (-)-epicatechin and (+)-catechin.

Item Type:Articles
Keywords:BIOAVAILABILITY BLACK TEA CANCER
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Mullen, Dr Bill and Stalmach, Dr Angelique and Crozier, Professor Alan
Authors: Stalmach, A., Mullen, W., Steiling, H., Williamson, G., Lean, M.E.J., and Crozier, A.
Subjects:Q Science > QH Natural history > QH345 Biochemistry
College/School:College of Medical Veterinary and Life Sciences > School of Life Sciences
Journal Name:Molecular Nutrition and Food Research
ISSN:1613-4125
ISSN (Online):1613-4133
Published Online:24 November 2009

University Staff: Request a correction | Enlighten Editors: Update this record