Bioavailability Catechin

The bioavailability and metabolism of catechins was studied in humans after consumption of black tea containing 15.48 mg of EGC, 36.54 mg of... 

Lambert, J.D. et al., Piperine enhances the bioavailability of the tea polyphenol (-)-epigallo-catechin-3-gallate in mice, J. Nutr., 134, 1948, 2004. 

Gu, L. House, S.E. Rooney, L.W. Prior, R.L. 2008. Sorghum extrusion increases bioavailability of catechins in weanling pigs. J. Agric. Food Chem. 56 1283-1288. Gu, L. House, S.E. Wu, X. Ou, B. Prior, R.L. 2006. Procyanidin and catechin contents and antioxidant capacity of cocoa and chocolate products. J. Agric. Food Chem. 54 4057-4061. 

The yield of flavonoids in the urine is dramatically dependent on the flavonoid under examination. For quercetin and anthocyanins, it is less than 1.5%, for isofla-vones it is 2 to 20% and for catechins it is -5% (reviewed in Scalbert and Williamson ). Flavonoids are found in urine as conjugated forms for example, rat urinary catechins are (+)-catechin-5-0-P-glucuronide and (-)-epicatechin-5-0-P-glucuronide. Generally, renal excretion is not a major pathway for intact flavonoids and the urinary content of flavonoids cannot be used as a biomarker of bioavailability or dietary intake. 

Cai, Y., Anavy, N.D., and Chow, H.H., Contribution of presystemic hepatic extraction to the low oral bioavailability of green tea catechins in rats. Drug Metab. Dispos., 30, 1246, 2002. 

Bioavailability of Catechins Affected by Pure or Mixed Form and... 

It is very important to know the bioavailability and biotransformation of tea catechins in humans because the pharmacokinetics, absorption, distribution, metabolism, and excretion of green tea determine its potential bioactivities in disease prevention in... 

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