Coffee constituents as modulators of Nrf2 nuclear translocation and ARE (EpRE)-dependent gene expression

Boettler, Ute; Sommerfeld, Katharina; Volz, Nadine; Pahlke, Gudrun; Teller, Nicole; Somoza, Veronika; Lang, Roman; Hofmann, Thomas; Marko, Doris

doi:10.1016/j.jnutbio.2010.03.011

« Previous Next »The Journal of Nutritional Biochemistry
Volume 22, Issue 5 , Pages 426-440, May 2011

Coffee constituents as modulators of Nrf2 nuclear translocation and ARE (EpRE)-dependent gene expression

Ute Boettler
- Department of Food Chemistry and Toxicology, University of Vienna, Währinger Str. 38, A-1090 Vienna, Austria
- Institute of Applied Biosciences, Section of Food Toxicology, Universität Karlsruhe (TH), Adenauerring 20, 76131 Karlsruhe, Germany
Katharina Sommerfeld
- Institute of Applied Biosciences, Section of Food Toxicology, Universität Karlsruhe (TH), Adenauerring 20, 76131 Karlsruhe, Germany
Nadine Volz
- Department of Food Chemistry and Toxicology, University of Vienna, Währinger Str. 38, A-1090 Vienna, Austria
- Institute of Applied Biosciences, Section of Food Toxicology, Universität Karlsruhe (TH), Adenauerring 20, 76131 Karlsruhe, Germany
Gudrun Pahlke
- Department of Food Chemistry and Toxicology, University of Vienna, Währinger Str. 38, A-1090 Vienna, Austria
Nicole Teller
- Department of Food Chemistry and Toxicology, University of Vienna, Währinger Str. 38, A-1090 Vienna, Austria
- Institute of Applied Biosciences, Section of Food Toxicology, Universität Karlsruhe (TH), Adenauerring 20, 76131 Karlsruhe, Germany
Veronika Somoza
- Research Platform Molecular Food Science, University of Vienna, Althanstrasse 14 (UZA II), A-1090 Vienna, Austria
Roman Lang
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Strasse 34, D-85354 Freising, Germany
Thomas Hofmann
- Chair of Food Chemistry and Molecular Sensory Science, Technische Universität München, Lise-Meitner-Strasse 34, D-85354 Freising, Germany
Doris Marko
- Institute of Applied Biosciences, Section of Food Toxicology, Universität Karlsruhe (TH), Adenauerring 20, 76131 Karlsruhe, Germany
- Corresponding author. Department of Food Chemistry and Toxicology, University of Vienna, Währinger Str. 38, A-1090 Vienna, Austria. Tel.: +43 66460277 70800; fax: +43 14277 52312.

Received 28 October 2009; received in revised form 16 March 2010; accepted 29 March 2010. published online 26 July 2010.

Abstract

Oxidative cellular stress initiates Nrf2 translocation into the nucleus, thus inducing antioxidant response element (ARE)-mediated expression of Phase II enzymes involved in detoxification and antioxidant defence. We investigated whether coffee extracts (CEs) of different proveniences and selected constituents have an impact on the Nrf2/ARE pathway in human colon carcinoma cells (HT29). Assessed as increased nuclear Nrf2 protein, Nrf2 nuclear translocation was modulated by different CEs as observed by Western blot analysis. In addition to the known Nrf2 activator 5-O-caffeoylquinic acid (CGA), pyridinium derivatives like the N-methylpyridinium ion (NMP) were identified as potent activators of Nrf2 nuclear translocation and ARE-dependent gene expression of selected antioxidative Phase II enzymes in HT29. Thereby, the substitution pattern at the pyridinium core structure determined the impact on Nrf2-signalling. In contrast, trigonelline was found to interfere with Nrf2 activation, effectively suppressing the NMP-mediated induction of Nrf2/ARE-dependent gene expression. In conclusion, several coffee constituents, partly already present in the raw material as well as those generated during the roasting process, contribute to the Nrf2-translocating properties of consumer-relevant coffee. A fine tuning in the degradation/formation of activating and deactivating constituents of the Nrf2/ARE pathway during the roasting process appears to be critical for the chemopreventive properties of the final coffee product.

Abbreviations: AB, Arabica Brazil, AC, Arabica Columbia, ARE/EpRE, antioxidant or electrophile response element, CE, coffee extract, CGA, 5-O-caffeoylquinic acid, DMP, dimethylpyridinium, NMP, N-methylpyridinium ion, Nrf2, NF-E2 p45 subunit-related factor 2, RI, Robusta India, T/C, test over control