TY - JOUR
T1 - Green tea flavan-3-ols
T2 - Colonic degradation and urinary excretion of catabolites by humans
AU - Roowi, Suri
AU - Stalmach, Angelique
AU - Mullen, William
AU - Lean, Michael E.J.
AU - Edwards And, Christine A.
AU - Crozier, Alan
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2010/1/27
Y1 - 2010/1/27
N2 - Following the ingestion of green tea, substantial quantities of flavan-3-ols pass from the small to the large intestine (Stalmach et al. Mol. Nutr. Food Res. 2009, 53, S44-S53; Mol. Nutr. Food Res. 2009, doi: 10.1002/mnfr.200900194). To investigate the fate of the flavan-3-ols entering the large intestine, where they are subjected to the action of the colonic microflora, (-)-epicatechin, (-)epigallocatechin, and (-)-epigallocatechin-3-0- gallate were incubated in vitro with fecal slurries and the production of phenolic acid catabolites was determined by GC-MS. In addition, urinary excretion of phenolic catabolites was investigated over a 24 h period after ingestion of either green tea or water by healthy volunteers with a functioning colon. The green tea was also fed to ileostomists, and 0-24 h urinary excretion of phenolic acid catabolites was monitored. Pathways are proposed for the degradation of green tea flavan-3-ols in the colon and further catabolism of phenolic compounds passing into the circulatory system from the large intestine, prior to urinary excretion in quantities corresponding to ca. 40% of intake compared with ca. 8% absorption of flavan-3-ol methyl, glucuronide, and sulfate metabolites in the small intestine. The data obtained point to the importance of the colonic microflora in the overall bioavailability and potential bioactivity of dietary flavonoids.
AB - Following the ingestion of green tea, substantial quantities of flavan-3-ols pass from the small to the large intestine (Stalmach et al. Mol. Nutr. Food Res. 2009, 53, S44-S53; Mol. Nutr. Food Res. 2009, doi: 10.1002/mnfr.200900194). To investigate the fate of the flavan-3-ols entering the large intestine, where they are subjected to the action of the colonic microflora, (-)-epicatechin, (-)epigallocatechin, and (-)-epigallocatechin-3-0- gallate were incubated in vitro with fecal slurries and the production of phenolic acid catabolites was determined by GC-MS. In addition, urinary excretion of phenolic catabolites was investigated over a 24 h period after ingestion of either green tea or water by healthy volunteers with a functioning colon. The green tea was also fed to ileostomists, and 0-24 h urinary excretion of phenolic acid catabolites was monitored. Pathways are proposed for the degradation of green tea flavan-3-ols in the colon and further catabolism of phenolic compounds passing into the circulatory system from the large intestine, prior to urinary excretion in quantities corresponding to ca. 40% of intake compared with ca. 8% absorption of flavan-3-ol methyl, glucuronide, and sulfate metabolites in the small intestine. The data obtained point to the importance of the colonic microflora in the overall bioavailability and potential bioactivity of dietary flavonoids.
KW - Catabolites
KW - Colonic degradation
KW - Flavan-3-ols
KW - Green tea
KW - Urinary excretion
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U2 - 10.1021/jf9032975
DO - 10.1021/jf9032975
M3 - Article
C2 - 20041649
AN - SCOPUS:74849092330
SN - 0021-8561
VL - 58
SP - 1296
EP - 1304
JO - Journal of Agricultural and Food Chemistry
JF - Journal of Agricultural and Food Chemistry
IS - 2
ER -