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Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures
Published on: March 28, 2017
Effect of natural phenols on the catalytic activity of cytochrome P450 2E1
Renata Mikstacka1, Jerzy Gnojkowski, Wanda Baer-Dubowska
1Department of Pharmaceutical Biochemistry, University of Medical Sciences, Grunwaldzka 6, 60-780 Poznań, Poland. rmikstac@mail.am.poznan.pl
Abstract:
The effect of protocatechuic acid, tannic acid and trans-resveratrol on the activity of p-nitrophenol hydroxylase (PNPH), an enzymatic marker of CYP2E1, was examined in liver microsomes from acetone induced mice. trans-Resveratrol was found to be the most potent inhibitor (IC(50) = 18.5 +/- 0.4 microM) of PNPH, while protocatechuic acid had no effect on the enzyme activity. Tannic acid with IC(50) = 29.6 +/- 3.3 microM showed mixed- and trans-resveratrol competitive inhibition kinetics (K(i) = 1 microM and 2.1 microM, respectively). Moreover, trans-resveratrol produced a NADPH-dependent loss of PNPH activity, suggesting mechanism-based CYP2E1 inactivation. These results indicate that trans-resveratrol and tannic acid may modulate cytochrome P450 2E1 and influence the metabolic activation of xenobiotics mediated by this P450 isoform.
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