Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (60)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Bu-Abbas, A.
Right arrow Articles by Ioannides, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bu-Abbas, A.
Right arrow Articles by Ioannides, C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 1994 Oxford University Press

research-article

Selective induction of rat hepatic CYP1 and CYP4 proteins and of peroxisomal proliferation by green tea

A. Bu-Abbas, M.N. Clifford, R. Walker and C. Ioannides 1

Division of Toxicology, School of Biological Sciences, University of Surrey Guildford, Surrey GU2 5XH, UK

1To whom corresponde should be addressed

Rats were exposed to freshly prepared aqueous extracts of green tea (2.5%w/v) as the sole source of drinking water for 4 weeks. Hepatic cytochrome P450 activity was determined using chemical probes, showing selectivity for particular isoforms, and by iminunoblot analysis employing polyclonal antibodies. Exposure to green tea gave rise to increases in the O-demethylation of methoxyresorufin and, to a lesser extent, in the dealkylations of ethoxyresorufin and pentoxy resorulin. An Increase was also seen In lauric acid hydroxylation but, In contrast, the N-demethylation of erythromycln was Inhibited. p-Nitrophenol oxidase activity was unaffected by the same treatment. Iminunoblot analysis revealed Increases In the apoprotein levels of CYP1A2 and CYP4A1 following treatment with green tea. A significant Increase was also noted in the CN–-insensitive palmitoyl CoA oxidation and this was paralleled by an increase In the levels of the peroxisomal trifunctional protein determined immunologically. Hepatic S9 and microsomal preparations from tea-treated animals were more effective than controls in activating 2-amlno-3-methylimidazol[4,5-f]quinoline and 2-aminoanthracene to mutagens In the Ames test. When N-nitrosopyrrolidine served as the promutagen, tea did not Influence its mutageniclty when isolated microsomes comprised the activation system but a significant inhibition was observed when hepatic S9 was used. The above findings are discussed within the context of the established anti-carcinogenic and anti-mutagenic properties of green tea.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Cancer Epidemiol. Biomarkers Prev.Home page
H.-H. S. Chow, I. A. Hakim, D. R. Vining, J. A. Crowell, M. E. Tome, J. Ranger-Moore, C. A. Cordova, D. M. Mikhael, M. M. Briehl, and D. S. Alberts
Modulation of Human Glutathione S-Transferases by Polyphenon E Intervention
Cancer Epidemiol. Biomarkers Prev., August 1, 2007; 16(8): 1662 - 1666.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Epidemiol. Biomarkers Prev.Home page
H-H. S. Chow, I. A. Hakim, D. R. Vining, J. A. Crowell, C. A. Cordova, W. M. Chew, M.-J. Xu, C.-H. Hsu, J. Ranger-Moore, and D. S. Alberts
Effects of Repeated Green Tea Catechin Administration on Human Cytochrome P450 Activity
Cancer Epidemiol. Biomarkers Prev., December 1, 2006; 15(12): 2473 - 2476.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Res.Home page
A. H. Conney
Enzyme Induction and Dietary Chemicals as Approaches to Cancer Chemoprevention: The Seventh DeWitt S. Goodman Lecture
Cancer Res., November 1, 2003; 63(21): 7005 - 7031.
[Abstract] [Full Text] [PDF]

Home page
 J. Nutr.Home page
C. S. Yang, J. Y. Chung, G.-y. Yang, S. K. Chhabra, and M.-J. Lee
Tea and Tea Polyphenols in Cancer Prevention
J. Nutr., February 1, 2000; 130(2): 472 - 472.
[Abstract] [Full Text]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.