QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schuier, M. Articles by Fischer, H. Search for Related Content PubMed PubMed Citation Articles by Schuier, M. Articles by Fischer, H.

---

Biochemical and Molecular Actions of Nutrients

Cocoa-Related Flavonoids Inhibit CFTR-Mediated Chloride Transport across T84 Human Colon Epithelia¹

Maximilian Schuier^*,, Helmut Sies, Beate Illek^* and Horst Fischer^*,2

^* Children’s Hospital Oakland Research Institute, Oakland, CA and Institute for Biochemistry and Molecular Biology I, Heinrich Heine University, Duesseldorf, Germany

²To whom correspondence should be addressed. E-mail: hfischer{at}chori.org.

Cocoa beans have historically been used as a treatment for diarrhea, leading us to hypothesize that polyphenols contained in cocoa inhibit intestinal Cl^– secretion. In this study, the dose-dependent effects of flavonoid compounds present in cocoa, or molecularly closely related compounds, were tested on forskolin-stimulated cystic fibrosis transmembrane conductance regulator (CFTR)-mediated Cl^– secretion across T84 colonic epithelia in Ussing chambers. Addition of cocoa extract or cocoa flavanols to the mucosal side of tissues caused partial inhibition following Michaelis-Menten kinetics and resulted in a rank order of maximum blocker effects as follows: epicatechin > catechin standardized cocoa preparation procyanidin B2. Half-maximal blocker concentrations (K_i) were not substantially different between the tested preparations and were in the range of 100 µmol/L. For comparison, the structurally related flavonoids, quercetin and luteolin, caused a total block of Cl^– currents with K_i values similar to the cocoa flavanols tested. Morin and baicalein were less effective blockers. Effects of test compounds on mucosal redox potential did not correlate with blocker activity. These data indicate that cocoa flavanols target intestinal CFTR Cl^– transport and may serve as mild inhibitors of cAMP-stimulated Cl^– secretion in the intestine.

KEY WORDS: • diarrhea • CFTR Cl^– channel • cocoa • flavonoids • CFTR blocker • redox potential

This article has been cited by other articles:

				D. Wu and Z. Hu Rutaecarpine Induces Chloride Secretion across Rat Isolated Distal Colon J. Pharmacol. Exp. Ther., April 1, 2008; 325(1): 256 - 266. [Abstract] [Full Text] [PDF]