Inhibition of Aryl Hydrocarbon-Induced Cytochrome P-450 1A1 Enzyme Activity and CYP1A1 Expression by Resveratrol
- Cellular Defense and Carcinogenesis Section, Basic Research Laboratory, Division of Basic Sciences, National Cancer Institute, Frederick Cancer Research and Development Center, National Institutes of Health, Frederick, Maryland
Abstract
We investigated the effect of resveratrol, a constituent of the human diet that has been shown to inhibit aryl hydrocarbon-induced carcinogenesis in animals, on the carcinogen activation pathway regulated by the aryl hydrocarbon receptor. Resveratrol inhibited the metabolism of the environmental aryl hydrocarbon benzo[a]pyrene (B[a]P) catalyzed by microsomes isolated from B[a]P-treated human hepatoma HepG2 cells. Resveratrol competitively inhibited, in a concentration-dependent manner, the activity of the carcinogen activating enzymes cytochrome P-450 (CYP)1A1/CYP1A2 in microsomes and intact HepG2 cells. Resveratrol inhibited the B[a]P-induced expression of the CYP1A1gene, as measured at the mRNA and transcriptional levels. Resveratrol abolished the binding of B[a]P-activated nuclear aryl hydrocarbon receptor to the xenobiotic-responsive element of theCYP1A1 promoter but did not itself bind to the receptor. Resveratrol was also effective in inhibiting CYP1A1transcription induced by the aryl hydrocarbon dimethylbenz[a]anthracene in human mammary carcinoma MCF-7 cells. These data demonstrate that resveratrol inhibits aryl hydrocarbon-induced CYP1A activity in vitro by directly inhibiting CYP1A1/1A2 enzyme activity and by inhibiting the signal transduction pathway that up-regulates the expression of carcinogen activating enzymes. These activities may be an important part of the chemopreventive activity of resveratrol in vivo.
Footnotes
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Send reprint requests to: Dr. Henry P. Ciolino, Basic Research Laboratory, Building 560/Room 12-05, National Cancer Institute-Frederick Cancer Research and Development Center, National Institutes of Health, Frederick, MD 21702-1201. E-mail:hciolino{at}mail.ncifcrf.gov
- Abbreviations:
- AH
- aryl hydrocarbon
- AHR
- aryl hydrocarbon receptor
- B[a]P
- benzo[a]pyrene
- CAT
- chloramphenicol acetyltransferase
- CYP
- cytochrome P-450
- DMBA
- dimethylbenz[a]anthracene
- DTT
- dithiothreitol
- EMSA
- electrophoretic mobility shift assay
- EROD
- ethoxyresorufin-O-deethylase
- ETRF
- ethoxyresorufin
- β-Gal
- β-galactosidase
- GAPDH
- glyceraldehyde-3-phosphate dehydrogenase
- poly(dI/dC)
- poly(deoxyinosinic/deoxycytidylic acid)
- RT
- reverse transcription
- PCR
- polymerase chain reaction
- TBE
- Tris/borate/EDTA
- TCDD
- 2,3,7,8-tetrachlorodibenzo-p-dioxin
- XRE
- xenobiotic responsive element
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- Received March 31, 1999.
- Accepted July 11, 1999.
- U.S. Government
