Suppression of CYP1A1 expression by naringenin in murine Hepa-1c1c7 cells.
Naringenin, dietary flavonoid, is antioxidant constituents of many citrus fruits. In the present study, we investigated the effect of naringenin on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible CYP1A1 gene expression in mouse hepatoma Hepa-1c1c7 cells. Naringenin alone did not affect CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity. In contrast, the TCDD-inducible EROD activities were markedly reduced upon concomitant treatment with TCDD and naringenin in a dose dependent manner. TCDD-induced CYP1A1 mRNA level was also markedly suppressed by naringenin. A transient transfection assay using dioxin-response element (DRE)-linked luciferase and electrophoretic mobility shift assay revealed that naringenin reduced transformation of the aryl hydrocarbons receptor(AhR) to a form capable of specifically binding to the DRE sequence in the promoter of the CYP1A1 gene. These results suggest the down regulation of the CYP1A1 gene expression by either naringenin in Hepa-1c1c7 cells might be antagonism of the DRE binding potential of nuclear AhR.
Department of Pharmacy, College of Pharmacy, Research Center for Proteineous Materials, Chosun University, Kwangju 501-759, Korea.
Ji Young
JY
Kim
Eun Hee
EH
Han
Dong Weon
DW
Shin
Tae Cheon
TC
Jeong
Eung Seok
ES
Lee
Eun-Rhan
ER
Woo
Hye Gwang
HG
Jeong
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000201:enzymology*; D019363:Cytochrome P-450 CYP1A1 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D044950:Flavanones / Q000494:pharmacology* / Q000627:therapeutic use; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology; D008113:Liver Neoplasms / Q000188:drug therapy / Q000201:enzymology*; D051379:Mice
D004791:Enzyme Inhibitors; D044950:Flavanones; D019363:Cytochrome P-450 CYP1A1; C005273:naringenin