• Archives of Pharmacal Research
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• 제19권6호
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• pp.514-519
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• 1996

In order to understand the mechanism of action of flavonoids on the drug metabolizing enzyme, cytochrome P450IA1, this study was undertaken to examine the effect of chrysin, morin, myricetin and aminopyrine on the activities of ethoxyresorufin O-deethylase and benzo(.alpha.) pyrene hydroxylase in the liver. In the isolated perfused rat liver that was pretreated with 3-methylcholanthrene (3MC), chrysin, morin, myricetin and aminopyrine inhibited the activity of ethoxyresorufin O-deethylase with concentration dependent manner. The isolated liver perfusion with chrysin, morin, myricetin and aminopyrine showed inhibition on the induction of ethoxyresorufin O- deethylase by 3MC. And also, in mouse liver hepa I cells, 3MC-stimulated the benzo(.alpha.)pyrene hydroxylase activity which was inhibited by chrysin, morin, myricetin and aminopyrine. These results strongly suggested that hydoxylated flavonoids interfered not only the induction of cytochrome P45OIA1 enzymes by 3MC but also the interaction of substrates and enzyme.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.100-105
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• 2002

• Food Science and Biotechnology
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• 제14권2호
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• pp.297-300
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• 2005

Effects of allyl sulfides on kinetic behavior of cytochrome P450 1 (CYP1)-catalyzed ethoxyresorufin O-deethylase (EROD) activity were studied using microsomes from benzo[a]pyrene-treated human hepatoma cells. Apparent $K_m$ and $V_{max}$ values were calculated as $2.8\;{\mu}M$ and $3.0\;{\mu}mol$ resorufin/min/mg protein based on Lineweaver-Burk plot of microsomal EROD activity, respectively. Diallyl disulfide (DADS) and diallyl trisulfide (DATS) affected $K_m$ and $V_{max}$ values of EROD activity and acted as mixed-type inhibitors for CYP1 isozymes. Apparent Ki values of DADS and DATS were calculated as 1.07 and 0.88 mM, respectively, by re-plotting slopes of Lineweaver-Burk plot and inhibitor concentrations.

• Archives of Pharmacal Research
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• 제20권5호
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• pp.404-409
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• 1997

Trout CYP1A-CAT expression construct was generated by cloning -3.5 Kb $5^I$ flanking DNA of trout liver CYP1A gene in front of CAT gene at pCAT-basic vector. Hepa 1 cells, which are known to contain a functional arylhydrbcarbon $receptor^I$ were transfected with trout CYP1A-CAT using lipofectin. 3-Methylcholanthrene (1 nM) was added into hepa 1 cells in culture in order to examine if $5^I$ flanking DNA of trout CYP1A gene could interact with mouse transactivating factors to bring about transcription of the chloramphenicol acetyltransferase(CAT) reporter gene. The level of CAT protein was measured by CAT ELISA and the level of CAT mRNA was determined by RTPCR. The treatment of 1 nM 3-methylcholanthrene resulted in two fold increases in CAT protein as well as CAT mRNA compared to untreated control hepa 1 cells. These data indicate that arylhydrocarbon receptors of mouse hepa 1 cells are functional to activate exogenously transfected trout CYP1A-CAT construct in terms of both transcription and translation of CAT. We also examined the effect of 3-methylcholanthrene on endogenous cyplal activity in hepa 1 cell. 3-Methylcholanthrene (1 nM) treatment to hepa 1 cells trahsfected with trout CYP1A-CAT construct stimulated the level of cyp1a1 mRNA by two folds and the activity of ethoxyresorufin-O-deethylase by two fold compared to that of control cells. In this study we reported that trout CYP1A-CAT reporter gene expression construct could be expressed by 3-methylcholanthrene treatment in mouse hepa 1 cells. Thus trout CYP1A-CAT could serve as a good model to study the mechanism of regulation of CYP1A1 gene expression.

• 환경생물
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• 제22권1호
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• pp.177-183
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• 2004

유기주석화합물인 tributyltin chloride (TBTC), tributyltin oxide (TBTO)와 triphenyltin chloride (TPTC)를 넙치 간장으로 만든 미크로좀에 in vitro적으로 노출시켜서 이들 화합물의 대사에 관여하는 mixed function oxidase (MFO) 중 cytochrome P450 (CYP) 농도와 7-ethoxyresorufin deethylase (EROD) 활성의 변화를 조사하였으며, 또한 in vivo 실험에서는 TPTC를 넙치에게 복강주사(7.5 mg $kg^{-1}$ BW)하여 간장의 MFO (CYP농도, NADPH cytochrome c 환원효소 활성, NADH chtochrome b5 환원 효소 활성, EROD 활성) 반응을 경시적으로 조사하였다. 그 결과, in vitro에서는 TBTC, TBTO 및 TPTC가 모두 CYP 농도와 EROD 활성을 저해하였으며, 저해력은 TPTC가 가장 컸고 이어서 TBTO, TBTC의 순이었다. 유기주석화합물의 노출농도와 노출시간과 비례하면서 저해정도가 커졌으며, 특히 EROD활성의 저해는 노출농도에 크게 의존적이었다. 그리고 in vivo실험에서도 유기주석 화합물은 CYP농도, NADPH cytochrome c 환원효소 활성, NADH cytochrome b5 환원효소 활성, EROD 활성을 억제하였다. EROD 활성은 오염물질에 의한 반응이 민감하고 재현성도 있어 바람직한 측정지표로 이용될 수가 있을 것이다.

• 환경생물
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• 제22권1호
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• pp.171-176
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• 2004

비이온성 계면활성제로 많이 쓰이는 알킬페놀류의 하나인 노닐페놀(nonylphenol)이 해산어류에게 미치는 영향을 조사하려고 주요 양식어종인 조피볼락에게 복강주사로 10 및 25 mg $kg^{-1}$을 1회 투여하였다. 한편 용제인 DMSO만을 주사한 sham구를 설정하여 비교하였다. 주사 후 7일간 간중량지수(hepatosomatic index)의 변화를 조사하였고, 또한 간장 미크로좀 중 대표적인 약물대사효소인 cytochrome P450 (CYP) 농도와 ethoxyresorufin deethylase (EROD) 활성의 변화도 측정하였다. 그 결과, 고농도(25 mg $kg^{-1}$) 주사구에서는 HSl가 감소하였는데, 이것은 NP가 간장에 독성이 있다는 것을 보여준다. 한편, 약물대사효소 중 CYP 농도는 유도되었지만 EROD 활성은 저해되는 경향을 보였다. 이번에 주사한 농도는 우리나라 연근해 해수 중의 NP 농도에 비해 매우 높은 수준이지만, 본 실험에서는 NP가 조피볼락에 게간장 독성을 보였고, 간장의 약물대사효소에도 영향을 미친다는 것을 확인할 수 있었다.

• Environmental Analysis Health and Toxicology
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• 제17권4호
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• pp.307-314
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• 2002

Effects of ($\pm$)-camphor on liver cytochrome P450 enzymes were investigated in male ICR mice. Mice were treated intraperitoneally with 0, 200, 400 and 800 mg/kg of ($\pm$)-camphor in corn oil for 3 consecutive days. Twenty four hr after the final treatment, the animals were subjected to necropsy. The activities of serum aspartate aminotransferase and serum alanine aminotransferase were slightly changed by the treatment with ($\pm$)-camphor at the doses used. Administration of ($\pm$)-camphor to mice significantly induced the hepatic activities of pentoxyresorufin O-depentylase and benzyloxyresorufin O-debenzylase and weakly induced ethoxyresorufin O-deethylase in dose-dependent manners. The present results suggested that ($\pm$)-camphor might act as a relatively specific inducer of hepatic cytochrome P450 2B in male ICR mice.

• BMB Reports
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• 제39권4호
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• pp.448-451
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• 2006

Chemopreventive and cytotoxic effect of genistein against human breast cancer cell lines was investigated. Genistein inhibited cell proliferation in estrogen receptor-positive (MCF-7) and estrogen receptor-negative (MDA-MB-231) human breast carcinoma cell lines. Cytochrome P450 (CYP) 1A1-mediated ethoxyresorufin O-deethylase (EROD) activity was inhibited by genistein in a concentrationdependent manner. Genistein significantly inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cyclooxy-genase-2 activity and protein expression at the concentrations of 10 (p < 0.05), 25 (p < 0.05) and 50 mM (p < 0.01). In addition, ornithine decarboxylase (ODC) activity was reduced to 53.8 % of the control after 6 h treatment with 50 mM genistein in MCF-7 breast cancer cells. These results suggest that genistein could be of therapeutic value in preventing human breast cancer.

• 한국연초학회지
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• 제20권1호
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• pp.99-107
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• 1998

Numerous studies have demonstrated a negative association between cigarette smoking and Parkinson's disease. The present study was undertaken to investigate whether chronic exposure of mice to cigarette smoke a(footed the metabolism of 1-methyl-1113,6-tetrahydro-pyridine (MPTP) by cytochrome P4SO (P-450) or flavin-containing monooxygenase (FMO) in the hepatic microsomes of C57BL6/J mice. Adult male C57BL6/J mice were exposed to mainstream smoke generated from 15 cigarettes for 10 min a day and 5 day per week for 6 weeks. MPTP (10 mg/kg body weight) was administered to mice by subcutaneous injection for 6 consecutive days. Microsolnal P-450 content was increased by MPTP, smoke exposure, or both, but NADPH cytochrome P-450 reductase activity was rather decreased by the same treatments. The activities of benzo(a)pyrene hydroxylase, 7-ethoxycoumarin O-deethylase and ethoxyresorufin O-deethylase were significantly increased by the exposure of cigarette smoke, but were not or little affected by MPTP treatment. Benzphetamine N-demethylase activity was not affected either by MPTP treatment or by cigarette smoke exposure, but it was significantly increased by the combined MPTP treatment with cigarette smoke exposure, showing their synergic effect for the induction of the enzyme activity. Interestingly, in vitro studies of hepatic FMO and P-450 system both O-oxygenation and N-demethylation of MPTP were increased in the smoke-exposed or in the MPTP-treated mice. These results suggest that the enhancement in the N-demethylation as well as O-deethylation of P-450 system and in the N-oxygenation of FMO activity by cigarette smoke exposure in mouse liver may contribute to attenuating the neurotoxic effects of MPTP on the nigrostriatal dopaminergic neurons.

• BMB Reports
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• 제32권3호
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• pp.232-238
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• 1999

Sex differences in the induction of microsomal cytochrome P-450 (CYP) and the activities of several related enzymes of Sprague-Dawley rats treated with 1-bromopropane (1-BrP) were investigated. Male and female rats were exposed to 50, 300, and 1800 ppm of 1-BrP per kg body weight (6 h a day,S days a week, 8 weeks) by inhalation. The mean body weight of 1-BrP treated groups increased according to the day elapsed, but four and five weeks respectively after the start of the exposure, the mean body weight of male and female rats had significantly reduced in the group treated with 1800 ppm 1-BrP compared with the control group (p<0.01). While the relative weights of liver increased in both sexes, statistical significance in both sexes was found only in the group receiving 1800 ppm/kg of 1-BrP (p<0.01). The total contents of CYP, $b_5$, NADPH-P-450 reductase, NADH $b_5$ reductase, ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-dealkylase (PROD), and p-nitrophenol hydroxylase (pNPH) activities were examined for the possible effects of 1-BrP. No significant changes in the CYP and $b_5$ contents, NADPH-P-450 reuctase, NADH $b_5$ reductase, ethoxyresorufin-O-deethylase (EROD), and pentoxyresorufin- O-dealkylase (PROD) were observed between the control and treated groups. The activity of pNPH increased steadily with the increase in the concentration of 1-BrP in both sexes, but was significantly increased only in the 1800 ppm-treated group of male rats (p<0.05). When Western blottings were carried out with three monoclonal antibodies (MAb 1-7-1, MAb 2-66-3, and MAb 1-98-1) which were specific against CYP1A1/2, CYP2B1/2, and CYP2E1, respectively, a strong signal corresponding to CYP2E1 was observed in microsomes obtained from rats treated with 1-BrP. Glutathione S-transferase (GST) activity and the content of lipid peroxide significantly increased in the treated groups compared with the control group (p<0.05). These results suggest that 1-BrP can primarily induce CYP2E1 as the major form and that GST phase II enzymes play important roles in 1-BrP metabolism, showing sex-dependence in the metabolic mechanism of 1-BrP in the rat liver.