Induction of cytochromes P450 1A1 and 1A2 by tanshinones in human HepG2 hepatoma cell line.
Diterpenoid tanshinones including tanshinone IIA (TIIA), cryptotanshinone (CTS), tanshinone I (TI) and dihydrotanshinone I (DHTI) are the major bioactive components from Danshen. The major aim of our present study was to investigate the induction potential of these four main components of tanshinones (TIIA, CTS, TI, and DHTI) on the expression of CYP1A1 and CYP1A2 in HepG2 cells. Our results showed that all of these four tanshinones caused a significant time- and concentration-dependent increase in the amount of CYP1A1/2 expression in HepG2 cells. These induction effects were further characterized through transcriptional regulation: the induction of CYP1A1/2 mRNA level by tanshinones was completely blocked by the transcription inhibitor actinomycin D; the expression of CYP1A1/2 heterogeneous nuclear RNA was induced by tanshinone treatment; and CYP1A1 mRNA stability was not influenced by these tanshinones. Interestingly, tanshinones plus B[a]P produced additive/synergistic effect on CYP1A1/2 induction. In addition, the tanshinone-induced CYP1A1/2 expression was abolished by the aryl hydrocarbon receptor (AhR) antagonist resveratrol, suggesting an AhR dependent transcription mechanism. In the reporter gene assay, while TI and DHTI significantly induced AhR-dependent luciferase activity, TIIA and CTS failed to induce this activity. Collectively, the tanshinones could induce CYP1A1 and CYP1A2 expression through transcriptional activation mechanism and exert differential effects on activating AhR in HepG2 cells. Our findings suggest that rational administration of tanshinones should be considered with respect to their effect on AhR and CYP1A1/2 expression.
Key Laboratory of Drug Metabolism and Pharmacokinetics, Key Unit of SATCM for Pharmacokinetics Methodology of TCM Complex Prescription, China Pharmaceutical University, Nanjing, China.
Rong
R
Zhang
Jianguo
J
Sun
Liping
L
Ma
Xiaolan
X
Wu
Guoyu
G
Pan
Haiping
H
Hao
Fang
F
Zhou
Jiye
J
A
Changhui
C
Liu
Hua
H
Ai
Lili
L
Shang
Haiyan
H
Gao
Ying
Y
Peng
Ping
P
Wan
Hui
H
Wu
Guangji
G
Wang
D045784:Abietanes / Q000494:pharmacology* / Q000633:toxicity; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis*; D019388:Cytochrome P-450 CYP1A2 / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology* / Q000633:toxicity; D004790:Enzyme Induction / Q000187:drug effects / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D056945:Hep G2 Cells; D006801:Humans
D045784:Abietanes; D004365:Drugs, Chinese Herbal; C021751:tanshinone; C504573:CYP1A2 protein, human; D019363:Cytochrome P-450 CYP1A1; D019388:Cytochrome P-450 CYP1A2