• Title/Summary/Keyword: cytochrome P450 isozymes

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Scavenging Activity of Reactive Oxygen Species and Inhibitory Effect of Cytochrome P450 from Circium japonicum Extract (대계 추출물의 할성산소 소거능 및 Cytochrome P450 효소 저해효과)

  • Kim, Hyuck;Yi, Hyo-Seung;Park, Won-Hwan;Moon, Jin-Young
    • The Korea Journal of Herbology
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    • v.22 no.1
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    • pp.53-61
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    • 2007
  • Objectives: Our previous studies have clearly demonstrated that the scavenging activity of reactive oxygen species (ROS), protective effect of lipid peroxidation (LPO), and inhibition of cytochrome P450 isozymes (CYPs) from the Circium japonicum aqua-acupuncture solution (CJAS). But, Circium japonicum water extracted solution (CJWS) was weakly reported in cardiovascular diseases such as oxidative stress-mediated atherosclerosis or its value evaluated. Methods: CJWS was assessed to determine the mechanism of its scavenging activity of ROS and inhibitory effect of CYP 2E1. Results: CJWS exhibited a concentration-dependent scavenger of DPPH and superoxide anions radicals using different assay systems. In addition, CJWS showed dose-dependent free radical scavenging activity, including hydroxyl radicals, peroxynitrite, and nitric oxide. The CJWS was also found to be effective in protecting rat liver homogenate against LPO. Futhermore, the CJWS showed significant inhibition of CYP 2E1 induced by pyrazol in a rat liver microsome. Conclusion : ROS and CYPs may play a role in several diseases, such as cardiovascular disease and heart failure. Our study demonstrated that the CJWS has excellent scavenging activity of ROS. Hence, it is worthwhile to investigate the potential effectiveness of CJWS in preventing oxidative stress-mediated cardiovascular diseases.

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The Beneficial Effect of Trolox on Sepsis-Induced Hepatic Drug Metabolizing Dysfunction

  • Park, Sang-Won;Lee, Sun-Mee
    • Archives of Pharmacal Research
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    • v.27 no.2
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    • pp.232-238
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    • 2004
  • Trolox is a hydrophilic analogue of vitamin E. The aim of this study was to investigate its effects on hepatic injury, especially alteration in cytochrome P450 (CYP)-dependent drug metabolism during polymicrobial sepsis. Rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). The rats were treated intravenously with Trolox (2.5 mg/kg) or vehicle, immediately after CLP. Serum aminotransferases and lipid peroxidation levels were markedly increased 24 h after CLP. This increase was attenuated by Trolox. Total CYP content and NADPH-P450 reductase activity decreased significantly 24 h after CLP. This decrease in CYP content was attenuated by Trolox. At 24 h after CLP, there was a significant decrease in the activity of these CYP isozymes: CYP1A1, 1A2, 2B1, and 2E1. However, Trolox differentially inhibited the decrease in CYP isozyme activity. Trolox had little effect on the decrease in CYP1A1 activity but Trolox significantly attenuated decreases in CYP1A2 and 2E1 activities. In fact, Trolox restored CYP2B1 activity to the level of activity found in control rats. Our findings suggest that Trolox reduces hepatocellular damage as indicated by abnormalities in hepatic drug-metabolizing function during sepsis. Our data also indicates that this protection is, in part, caused by decreased lipid peroxidation.

IN HUMAN BREAST CANCER MCF-7 CELLS, ESTROGEN INVOLVES IN CYPIA1 GENE EXPRESSION.

  • Hwang, J.E.;S.H.Eo;Cho, S.N.;Y.Y.Sheen
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1997.04a
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    • pp.107-107
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    • 1997
  • Cytochrome P450 enzymes have been intensively investigated in hepatic tissues and several mammalian cell lines. Compared to most studies about cytochrome P450 isozymes in liver in vivo and hepatic, cell lines in vitro, the study of cytochrome P450IA1 in human breast cancer cells could be very important to understand the mechanism of the regulation of CYPIA1 gene expression and cell growth. MCF-7 human breast cancer cells are well characterized to study estrogen and antiestrogen action due to the fact that they contain high level of estrogen receptor and have biological markers characterized. And also MCF-7 cells express high level of arylhydrocarbon hydroxylase activity and human cytochrome P450IA1 cDNA was cloned from MCF-7 cells. Ah receptor was characterized in many breast cancer cell lines and polycyclic aromatic hydrocarbon such as 3-MC induced the expression of CYPIA1 gene and cytochrome P450- dependent monooxygenase activity. We undertook a study to examine the effect of estrogens and other chemicals on the regulation of human CYPIA1 gene expression in MCF-7 cells via RTPCR analysis, that might help us to understand the mechanism of the regulation of CYPIA1 gene expression and MCF-7 cell growth. Expression vector containing the functional 5'-regulatory region of human CYPIA1 fused to the CAT reporter gene was transfected into estrogen receptor positive MCF-T cells or estrogen receptor negative MDA-MB-231 cells. After these cells were treated with various chemicals, RTPCR was carried out to measure both CYPIA1 mRNA and CAT mRNA levels. 1nM 3-MC increased in both P450 and CAT mRNA levels over those of control by two folds in MCF-7 cells but does not in MDA-MB-231 cells. Estrogen or tamoxifen or retinoic acid or chrysin decreased in both P450 and CAT mRNA levels that were induced by 3-MC in MCF-7 when each chemical was administered with 3-MC concomitantly. These results suggested that the level of CYPIA1 gene expression is modulated with estrogen-related molecules and make it possible to speculate that ER is related to CYPIA1 gene expression and cell growth in breast cancer cells. [Supported by grants from the Korean Ministry of Education ]

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No Role of Protected Region B of Human Cytochrome P4501A2 Gene (CYP1A2) As an AP-1 Response Element

  • Chung, In-Jae;Jung, Ki-Hwa
    • Archives of Pharmacal Research
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    • v.25 no.3
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    • pp.375-380
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    • 2002
  • Cytochrome P4501A2 (CYP1A2) is a member of the cytochrome P450 family of isozymes involved in the phase I drug metabolism of vertebrates. CYP1A2 is responsible for the activation of a number of aromatic amines to mutagenic and carcinogenic forms. Thus, the level of CYP1A2, which varies among different populations, may determine an individual's susceptibility to these chemicals. We have previously reported on the importance of a cis element named PRB (protected region B) in the regulation of human Cytochrome P4501A2 (CYP1A2) gene, which appeared to act as a positive regulatory element. Closer examination of the PRB sequence (-2218 to -2187 bp) revealed a putative AP-1 binding site, TGACTAA, at -2212 bp (Chung and Bresnick, 1997). To elucidate the role of AP-1 in CYP1A2 regulation, we transiently overexpressed c-Jun and c-Fos transcription factors in human hepatoma HepG2 cells, and examined their influence on the CYP1A2 promoter activity by reporter gene assays. Cotransfection of the c-Jun and the c-Fos expression vectors increased the induced transactivation by five to six fold from the CYP1A2 promoter constructs. However, deletion of the PRB element did not affect the degree of activation by the c-Jun and the c-Fos. Therefore, it is unlikely that the c-Jun and the c-Fos activate the CYP1A2 promoter through this AP-1 consensus-like sequence in the PRB region.

Drug-Drug Interactions : Mood Stabilizers and Anti-Anxiety Drugs (약물상호작용 : 기분안정제와 항불안제)

  • Kim, Young Hoon;Rhee, Jung Goo
    • Korean Journal of Biological Psychiatry
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    • v.7 no.1
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    • pp.34-45
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    • 2000
  • Pharmacotherapy of bipolar disorder is a rapidly evolving field. Mood stabilizers and anticonvulsants have varying biochemical profiles which may predispose them to different adverse effects and drug-drug interactions. Several of the new anticonvulsants appear less likely to have the problems with drug-drug interaction. To provide more effective combination pharmacotherapies, clinicians should be allowed to anticipate and avoid pharmacokinetic and pharmacodynamic drug-drug interactions. We reviewed the role of cytochrome P450 isozymes in the metabolism of the drugs and their interactions. The drug-drug interactions of several classes of drugs which used as mood stabilizers and new anticonvulsants, some of which may have psychotropic profiles, are discussed mainly in this article. Finally, potential pharmacokinetic interactions between the benzodiazepines and other coadministered drugs are discussed briefly.

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CJ-11668, a new selective and potent cox-2 inhibitor, has long-acting pharmacokinetic profiles

  • Park, Hyun-Jung;Kang, Hye-Jung;Chung, Young-Mee;Chun, Hyung-Ok;Hong, Kwang-Hee;Kim, Il-Hwan;Kim, Taek-Rho;Noh, Hyun-Jung;Kim, Deog-Yeor
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.88.1-88.1
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    • 2003
  • CJ-11668 is a new potent and selective COX-2 inhibitor (IC$\sub$50/ COX-2 65nM; COX-l/COX-2 ratio 770). The pharmacokinetic profile of CJ-11668 (20 mg/kg, p.o.) in the rat was characterized by high bioavailability (90%) and long plasma half-life (11.7 hr) with low clearance (0.4 L/hr/kg). In the dog, the PK profiles (2 mg/kg, p.o.) also showed long plasma half-life (l7.9hr) with low clearance (0.5 L/hr/kg), and the bioavalability of 60%. The inhibition of CJ-11668 infive different cytochrome P450 isozymes (1A2, 2C9, 2C19, 2D6 and 3A4) was determined in vitro and had observed no significant effect. (omitted)

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Measurement of CYP450 Enzymes Activity of Bosentan in HepaRG Cell (HepaRG 세포를 이용한 Bosentan 약물의 CYP450 효소활성 측정)

  • Han, Kyoung-Moon;Jung, Jung-A;Sin, Ji-Soon;Cha, Hye-Jin;Bae, Young-Ji;Kim, Hyun-Uk;Kim, Young-Hoon;Seong, Won-Keun;Kang, Hoil
    • YAKHAK HOEJI
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    • v.58 no.4
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    • pp.255-261
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    • 2014
  • Poly-pharmacy has been on the rise because of aging of population and chronic disease. Most of drug metabolism happens in the liver by CYP isozymes and the metabolism by CYP450 enzymes. The Cytochrome P450 (CYP) is a superfamily of enzymes that catalyzes the oxidations of many endogenous and exogenous compounds. Primary human Hepatocytes (HH) are considered as the gold standard model for In vitro drug interaction studies. However, there are several limitations (cost, limited life span) for using HH cells. HepaRG cells are being used as a possible alternative. HepaRG cells were cultured in William E medium containing the positive control inducers (1A2: 10, 25, 50 ${\mu}M$ omeprazole, 2C9 and 2C19: 10 ${\mu}M$ rifampin, 3A4: 10, 25, 50 ${\mu}M$ rifampin) at $37^{\circ}C$, 5 % $CO_2$ in a humidified atmosphere. This study was to evaluate the induction of CYP isozymes (1A2, 2C9, 2C19 and 3A4) using LC-MS/MS. We evaluated the potential induction ability of Bosentan, as a drug of pulmonary artery hypertension, in HepaRG cells. For reference, dose of the Bosentan is determined to the basis of the $C_{max}$ (835 mg/ml) value. The enzyme activity demonstrated that CYP2C9 and 3A4 were induced up to 20 times by Bosentan. Like as In vivo, the enzyme activity of CYP2C9 and CYP3A4 is significantly induced in a dose-dependent by Bosentan.

Effects of Enzyme Inducers and Glutathione on the Embryotoxicity of Cyclophosphamide in Cultured Rat Embryos (효소유도제 및 glutathione이 전배자배양된 랫드태자에서 cyclophosphamide의 독성에 미치는 영향)

  • 한순영;신재호;권석철;강명옥;이유미;김판기;양미라;박귀례;장성재
    • Toxicological Research
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    • v.11 no.1
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    • pp.31-36
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    • 1995
  • Cyclophosphamide (CP) must be enzymatically activated by cytochrome P450(CYP)-linked mixed-function oxidation pathway to be either mutagenic or teratogenic. Influences of alterations in hepatic mixed-function oxidase acitivity and glutathione (GSH) content on the embryotoxicity of CP were studied in rat whole embryo culture system. The embryotoxicity of CP was compared using rat S-9 fraction (S-9) pretreated with chemicals inducing different CYP isozymes, acetone (ACE), Aroclor 1254 (ARO), $\beta$-naphthoflavone (NAF) and phenobarbital (PHE). When 10.5 day embryos were cultured in the immediately centrifuged rat serum for 48 hrs using general gas char{ging schedule, CP$(40{\mu}g/ml)$ with S-9 induced by either NAF or PHE increased the incidence of realformations and significantly decreased embryonic growth compared with the non-induced S-9 group. ACE or ARO induced S-9 group showed no significant difference in embryonic growth. These data suggest that PB and/or NAF inducible CYP isoenzymes are mainly involved in the activation of CP. To examine the effect of GSH on the embryotoxicity of CP, 10.5 day embryos were exposed to CP and S-9 after preincubation with 10 mM of GSH for 3 hrs. In the GSH pretreated group the growth of embryos increased significantly compared with that of the untreated group, suggesting that GSH may protect embryos in culture from some toxic effects of CP.

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The Effect of Estrogen Deficiency on Ethanol Metabolism in Ovariectomized Rats (난소절제 랫트에서 에스트로겐 저하가 알코올 대사에 미치는 영향)

  • Chang, Bo-Yoon;Kim, Sung-Yeon
    • YAKHAK HOEJI
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    • v.54 no.6
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    • pp.522-528
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    • 2010
  • This study was designed to examine the effect of estrogen deficiency on the metabolism of ethanol in ovariectomized rats. Female rats were assigned to an ovariectomy (OVX) and a sham (SHAM) surgery group. Gain body weight was greater in incresed in OVX group and especially uterus weight significantly decrease depending on the concentration of estrogen after 3 month of ovariectomy. Ethanol at the tolerative dose (6 g/kg) was injected to rats by oral administration to measure the concentration of ethanol in blood. The area under the blood concentration time curve (AUC) was significantly lower in OVX group than SHAM group. The significant decrease in AUC in OVX group indicates that the estrogen deficiency leads to changes of the factors related to ethanol metabolism. Activity of hepatic alcohol dehydrogenase was not significantly influenced by the ovariectomy and also the ethanol elimination rate in vivo was not different. Cytochrome P450 isozymes did not show any changes except CYP 1A1 and 2E1. Level of hepatic glutathione in OVX group was higher after treatment of ethanol. Therefore the reduction of AUC appears not to be directly associated with the difference of ethanol metabolizing enzyme, but to be related with the physical factors like body weight.

Function of NADPH Oxidases in Diabetic Nephropathy and Development of Nox Inhibitors

  • Lee, Sae Rom;An, Eun Jung;Kim, Jaesang;Bae, Yun Soo
    • Biomolecules & Therapeutics
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    • v.28 no.1
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    • pp.25-33
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    • 2020
  • Several recent studies have reported that reactive oxygen species (ROS), superoxide anion and hydrogen peroxide (H2O2), play important roles in various cellular signaling networks. NADPH oxidase (Nox) isozymes have been shown to mediate receptor-mediated ROS generation for physiological signaling processes involved in cell growth, differentiation, apoptosis, and fibrosis. Detectable intracellular levels of ROS can be induced by the electron leakage from mitochondrial respiratory chain as well as by activation of cytochrome p450, glucose oxidase and xanthine oxidase, leading to oxidative stress. The up-regulation and the hyper-activation of NADPH oxidases (Nox) also likely contribute to oxidative stress in pathophysiologic stages. Elevation of the renal ROS level through hyperglycemia-mediated Nox activation results in the oxidative stress which induces a damage to kidney tissues, causing to diabetic nephropathy (DN). Nox inhibitors are currently being developed as the therapeutics of DN. In this review, we summarize Nox-mediated ROS generation and development of Nox inhibitors for therapeutics of DN treatment.