Dietary polyphenols (−)-epicatechin and chrysin inhibit intestinal glucuronidation metabolism to increase drug absorption
✍ Scribed by Takashi Mizuma; Shoji Awazu
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 80 KB
- Volume
- 93
- Category
- Article
- ISSN
- 0022-3549
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✦ Synopsis
The effect of dietary polyphenols on the intestinal glucuronidation and absorption of a model phenolic drug, a-naphthol (a-NA), was studied in isolated rat small intestine. (À)-Epicatechin significantly inhibited the glucuronidation of a-NA. Chrysin, (À)-epigallocatechin galleate (EGCG), and quercetin decreased the rate of glucuronidation, although not significantly. Baicalin did not affect the glucuronidation. The rate of absorption of a-NA in the presence of these polyphenols also varied. The absorption clearance (CL abs ) and the metabolic clearance (CL met ) were inversely correlated, and this relationship was well explained in the metabolic inhibition model with kinetic parameters (knowledge-based prediction) which characterizes the relationship between the CL abs and CL met of a-NA (Biochim Biophys Acta 1998, 1425, 398.). These results indicate that the concomitant intake of some polyphenols can increase the absorption of a phenolic drug, and the effect is predictable. (À)-Epicatechin and chrysin are effective for the inhibition of glucuronidation and promotion of intestinal drug absorption.