A preliminary investigation of the impact of catechol-O-methyltransferase genotype on the absorption and metabolism of green tea catechins
| Autor: | Rosalind J. Miller, Tony Dadd, A. Louise Brown, Anne Marie Minihane, Kim G. Jackson, Beate Nicol, Joanne L. Dick, Andrew E. Mayes |
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| Rok vydání: | 2010 |
| Předmět: |
Male
Medicine (miscellaneous) Flavan-3-ol Pilot Projects Green tea extract Pharmacology Epigallocatechin gallate Catechol O-Methyltransferase complex mixtures Methylation Polymorphism Single Nucleotide Intestinal absorption Catechin chemistry.chemical_compound Phenols Humans Genetic Association Studies chemistry.chemical_classification Nutrition and Dietetics Catechol-O-methyl transferase Tea Plant Extracts Homozygote food and beverages Middle Aged Kinetics Epicatechin gallate chemistry Biochemistry Amino Acid Substitution Intestinal Absorption Polyphenol Dietary Supplements Female |
| Zdroj: | European journal of nutrition. 51(1) |
| ISSN: | 1436-6215 |
| Popis: | Green tea is thought to possess many beneficial effects on human health. However, the extent of green tea polyphenol biotransformation may affect its proposed therapeutic effects. Catechol-O-methyltransferase (COMT), the enzyme responsible for polyphenolic methylation, has a common polymorphism in the genetic code at position 158 reported to result in a 40% reduction in enzyme activity in in vitro studies. The current preliminary study was designed to investigate the impact of COMT genotype on green tea catechin absorption and metabolism in humans. Twenty participants (10 of each homozygous COMT genotype) were recruited, and plasma concentration profiles were produced for epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), epicatechin (EC) and 4′-O-methyl EGCG after 1.1 g of Sunphenon decaffeinated green tea extract (836 mg green tea catechins), with a meal given after 60 min. For the entire group, EGCG, EGC, EC, ECG and 4′-O-methyl EGCG reached maximum concentrations of 1.09, 0.41, 0.33, 0.16 and 0.08 μM at 81.5, 98.5, 99.0, 85.5 and 96.5 min, respectively. Bimodal curves were observed for the non-gallated green tea catechins EGC and EC as opposed to single-peaked curves for the gallated green tea catechins EGCG and ECG. No significant parametric differences between COMT genotype groups were found. In conclusion, the COMT Val(158/108)Met does not appear to have a dramatic influence on EGCG absorption and elimination. However, further pharmacokinetic research is needed to substantiate these findings. |
| Databáze: | OpenAIRE |
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