Epicatechin selectively prevents nitration but not oxidation reactions of peroxynitrite

Peter Schroeder, Lars Oliver Klotz, Darius P. Buchczyk, Christian D. Sadik, Tankred Schewe, Helmut Sies*

*Corresponding author for this work
78 Citations (Scopus)

Abstract

The flavanol (-)-epicatechin has been found to protect against damage inflicted by peroxynitrite, an inflammatory intermediate. Here, epicatechin was tested in systems of increasing complexity. The compound efficiently protected against nitration of protein tyrosine residues by peroxynitrite (IC50 ≈ 0.02 mol epicatechin/mol peroxynitrite). However, at epicatechin concentrations completely preventing nitration of tyrosine by peroxynitrite, protection against the oxidative inactivation of glyceraldehyde-3-phosphate dehydrogenase or soybean lipoxygenase-1 was marginal (IC50 > 1 mol epicatechin/mol peroxynitrite), approximately two orders of magnitude less. Likewise, epicatechin was relatively ineffective against oxidation of thiols in cell lysates, and against the oxidation of 2′,7′-dichlorodihydrofluorescein in cultured cells. The activation of the kinases Akt/protein kinase B, ERK1/2 and p38-MAPK by peroxynitrite in murine aorta endothelial cells was not altered by epicatechin, suggesting that activation of these kinases is due to processes other than tyrosine nitration.

Original languageEnglish
JournalBiochemical and Biophysical Research Communications
Volume285
Issue number3
Pages (from-to)782-787
Number of pages6
ISSN0006-291X
DOIs
Publication statusPublished - 01.01.2001

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