• Title/Summary/Keyword: cytochrome b5

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Induction of Phase II Enzymes and Inhibition of Cytochrome P450 Isozymes by Chitosanoligosaccharides

  • SHON, YUN-HEE;NAM, KYUNG-SOO
    • Journal of Microbiology and Biotechnology
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    • v.15 no.1
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    • pp.183-187
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    • 2005
  • Abstract The cancer chemopreventive potential of chitosanoligosaccharides was investigated by measuring the induction of quinone reductase and glutathione S-transferase activities and inhibition of cytochrome P450 1A1, 2B1, and 2E1 activities. Chitosanoligosaccharide I (1-${\kappa}$Da${\kappa}$Da) significantly induced glutathione S-transferase activity with a maximal 1.5-fold increase at 500 ${\mu}$g/ml, while chitosanoligosaccharide II (3-${\kappa}$Da${\kappa}$Da) (500 ${\mu}$g/ml) strongly induced quinone reductase (p<0.01) and glutathione S-transferase (p<0.005) activities. The in vitro incubation of rat liver microsomes with chitosanoligosaccharides I and II (2.5, 5, 50, and 500 ${\mu}$g/ml) showed a dose-dependent inhibiton of cytochrome P450 1A1, 2B1, and 2E1 activities. Chitosanoligosaccharide II was a more potent inhibitor of cytochrome P450 2B1 activity than chitosanoligosaccharide I. Accordingly, these findings suggest that chitosanoligosaccharides are potential chemopreventive agents.

Expression of Cytochrome $b_{5}$ Retropseudogenes in Hunam Blood

  • Hwang, Mi-Sun;Alan W.Steggles;Yoo, Min
    • Biomedical Science Letters
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    • v.9 no.3
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    • pp.167-170
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    • 2003
  • Cytochrome $b_{5}$($b_{5}$) can be found in a variety of tissues and plays a role in the electron transfer pathways. Several retropseudogenes (numbered as I, II, II, IV, V) have been identified and well investigated for their structures. However, retropseudogene I is not clear in terms of its location on the chromosome. In addition the structure and the exression of retropseudogene V have not been confirmed. To examine the structure of bs retropseudogenes V and to see whether it is expressed in human blood we applied recombinant DNA technologies including polymerase chain reaction (PCR) and DNA sequencing. Retropseudogene V turned out to contain open reading frame (ORF) within its structure, however, no evidence of its expression was detected. Retropseudogene I was also found on the chromosome V. This study should contribute to the understanding of the structure of bs gene family.

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In vitro and In vivo Responses of Hepatic Xenobiotic Metabolizing Enzymes in Flounder (Paralichthys olivaceus) Exposed to Formalin (Formalin에 노출시킨 넙치 (Paralichthys olivaceus) 간장 약물대사효소의 in vivo 및 in vitro 반응)

  • Lee, Ji-Seon;Ha, Jin-Hwan;Lee, Kyoung-Seon;Jeon, Joong-Kyun
    • Korean Journal of Environmental Biology
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    • v.24 no.2 s.62
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    • pp.195-200
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    • 2006
  • The response of hepatic mixed function oxygenase (MFO) system was investigated in olive flounder exposed to formalin. Hepatic microsome of olive flounder incubated in vitro with formalin demonstrated the induction of cytochrome P450 (CYP), ethoxyresorufin deethylase (EROD), cytochrome P450 reductase (P450R) and cytochrome b5 reductase (b5R) activity. In addition, olive flounder was exposed to 100, 300 and 500 ppm of formalin for 1 h and then transferred to a flow-through type of 1000 L aquarium. Hepatic MFO enzyme activity was determined for 72 h. As the result, hepatic CYP, P450R and EROD activities increased following exposure of formalin, but b5R and GST showed no significant change. These results imply that CYP and P450R can be considered as main hepatic enzymes involving in detoxification of formalin.

A Study on the metabolism mechanism of Benzene, Toluene and Xylene by Cytochrome P-450 dependent radical-mediated (Cytochrome P-450 의존성 radical 전달에 의한 Benzene, Toluene, Xylene의 대사기전 연구)

  • 김기웅;장성근;김양호;문영한
    • Toxicological Research
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    • v.11 no.2
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    • pp.205-213
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    • 1995
  • This study was undertaken to investigate the effects of organic solvents on xenobiotic metabollzing enzyme system in vivo by meaas of experimental conditions i.e. (1) single group which was treated by benzene (B), toluene (T) and xylene (X), respectively, (2) combination group which was treated by mixture of benzene+toluene (BT), benzene+xylene (BX), and toluene+xylene (TX), respectively, (3) mixture group which was treated by benzene+ toluene+xylene mixture (M), and to interpreat the interaction between the organic solvents metabolizing enzymes. 1. The contents of cytochrome P-450 in liver microsomes were increased (p < 0.01) in organic solvents treated groups, and the contents of cytochrome P-450 were increased by following order of B < T < M < BT=BX < X < TX. 2. The activity of cytochrome P-450 dependent AHHase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the activity of AHHase was increased by following order of B < T < BT=BX=TX=xylene < M. 3. The activity of NADPH P-450 reductase was significantly higher in organic solvents treated groups than in control group (p < 0.01), and the order of M < combinated group < X < T

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Modulation of Cytochrome P-450 Induction by Long-Term Supplementation with Korean Red Ginseng to Rats (홍삼의 장기 투여가 흰쥐 간 대사효소 유도에 미치는 영향)

  • Lim, Heung-Bin
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.6
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    • pp.437-443
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    • 2007
  • This study was carried out to investigate the effect of dietary supplementation with red ginseng water-extracts on the induction of microsomal cytochrome P-450 in rats. Phenobarbital (PB) and 3-methylcholanthrene (3-MC), P-450 inducers, were administered to 3- or 12-month old rats received red ginseng extracts (25 mg/kg) from 6 weeks to 12 months for 3 days. PB and 3-MC increased levels of P-450, P-450 reductase, ethoxycoumarin O-deethylase, benzphetamine N-demethylase and glutathione-S-transferase in the liver of rats. However, chronic administration of red ginseng significantly reduced these increase of enzyme levels induced by P-450 inducers. Chronic administration of red ginseng did not affect the induction of cytochrome $b_5$ and NADH cytochrome $b_5$ reductase by P-450 inducers. It is suggested that the induction of cytochrome P-450 system in the liver in relation to xenobiotics toxicity can be modulated by long-term supplementation with Korean red ginseng to rats.

The Enhancement of Cytochrome P-450 Mediated Aryl Hydroxylation of Bentazon in Rice Microsomes (벼에서 Bentazon 히드록시화반응에 관련된 Cytochrome P-450 활성(活性) 증진(增進)에 관한 연구(硏究))

  • Pyon, J.Y.;Balke, N.E.
    • Korean Journal of Weed Science
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    • v.17 no.1
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    • pp.59-65
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    • 1997
  • Bentazon 6-hydroxylase (B6H) and cinnamic acid 4-hydroxylase (CA4H) activities were determined in rice (Oryza sativa L.) microsomes to study methods of enhancing cytochrome P-450 mediated aryl hydroxylation of bentazon by hydoxylase inducing compounds. Pretreating rice seeds with 1,8-naphthalic anhydride at 0.5-2% and fenclorim at 5 and 10 ${\mu}M$ increased B6H and CA4H activities. Treatments of rice seedling with ethanol 2.5% enhanced B6H and CA4H activities, and with phenobarbital at 12 mM enhanced B6H activity, and CA4H activity was enhanced at 2 mM. B6H activity was synergistically enhanced by combined treatments of ethanol 2.5 or 5% and phenobarbital 8 or 12mM and also that of 1,8-naphthalic anhydride 0.5 or 1% and phenobarbital 8 or 12 mM, but CA4H activity was decreased by combined treatment. Five-day-old rice seedlings showed higher B6H and CA4H activities which decreased with seedling age.

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DIFFERENTIAL INDUCTION OF RAT LIVER MICROSOMAL CYTOCHROME-DEPENDENT MONOOXYGENASE AND UDP-GLUCURONOSYLTRANSFERASE ACTIVITIES BY VARIOUS NARCOTIC DRUGS

  • Hong, Young-Sook;Pae, Young-Sook
    • Toxicological Research
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    • v.5 no.1
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    • pp.17-25
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    • 1989
  • Chronic adminstraction of morphine to adult male rats has long been known to lower hepatic cytochrome p-450 content and its dependent mixed-function oxidase activity. Following the treatment of adult male rats with morphine, pethidine pentazocine and codeine and also by concomitant adminstration of naloxone activities of microsomal electron transfer in the adult male rats were examined. In present study, the acute treatment of mature male rats with a dose of narcotic drugs higher than that used chronically also reduces their hepatic cytochrome p-450.

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SYNERGISTIC EFFECT OF HUMAN CYTOCHROME B5 COEXPRESSION ON THE METABOLIC ACTIVITY OF CYP1A2 IN CHINESE HAMSTER OVARY CELLS

  • Kang, Jin-Sun;Kang, Hyuck-Joon;Dong, Mi-Sook;Park, Chang-Hwan
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.188-188
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    • 2001
  • Human cytochrome B5 (CYB5) was coexpressed with cytochrome P450 1A2 (CYP1A2), NADPH-CYP450 reductase (CYPR) and Ν-acetyltransferase 2 (NAT2) in Chinese hamster ovary (CHO) cells. The expression of four proteins was determined by Western blot analyses. The introduction of cDNAs to CHO cells were transduced via retroviral vectors. The cytotoxicity assay of 2-aminoanthracene (2-AA) and aflatoxin B$_1$were approximately 4-fold more sensitive than CYB5 free cells.(omitted)

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Identification and characterization of cytochrome $bc_1$ complex and cytochrome c oxidase in chromatophore of rhodopseudomonas gelatinosa (Rhodopseudomonas gelatinosa의 chromatophore에서 시토크롬 $bc_1$ 복합체와 시토크롬 c 산화효소의 확인 및 특성연구)

  • 강대길;최명재;최원기
    • Korean Journal of Microbiology
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    • v.29 no.4
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    • pp.243-249
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    • 1991
  • The chromatophore from the chemotrophically grown facultative anaerobic photosynthetic bacterium, Rhodopseudomonas gelatinosa ATCC 17013 was isolated through stepwise sucrose gradient centrifugation. The isolated chromatophore showed high activities of the cytochrome $bc_{1}$ complex and cytochrome c oxidase. The activity of cytochrome $bc_{1}$ complex was completely inhibited by .5$\mu$M antimycin A,10$\mu$M myxothiazol, and that of cytochrome c oxidase was completely inhibited by .$50\mu$M KCM and $100\mu$M $NaN_{3}$but not inhibited by carbon monoxie. The activity of cytochrome c oxidase of th chromatophore was increased by addition of ionophores or protonophores. The reduced-oxidised difference sspectrum of cytochrome $bc_{1}$ complex isolated by affivity chromatography showed the absorption maxima at 553 nm(shoulder at 547 nm), 520 nm, and 418.5 nm, on the other hand, that of cytochrome c oxidase showed .alpha., .betha. and soret peaks at 554 nm, 523 nm, and 421 nm, respectively. The cytochrome c oxidase from chemotrophically grown Rhodopseudomonas gelatinosa seems to be a b-type cytochrome c oxidase.

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Cross Resistance and Point Mutation of the Mitochondrial Cytochrome b of Bifenazate Resistant Two-spotted Spider Mite, Tetranychus urticae (Bifenazate 저항성 점박이응애에 대한 교차저항성과 미토콘드리아 cytochrome b의 점돌연변이)

  • Lee, Kyo-Ri;Koo, Hyun-Na;Yoon, Chang-Mann;Kim, Gil-Hah
    • The Korean Journal of Pesticide Science
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    • v.14 no.3
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    • pp.247-254
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    • 2010
  • Two-spotted spider mite, Tetranychus urticae was collected from the rose greenhouse in Chilgok, Gyeongbuk Province in December 2000. This population has been selected for ten years with bifenazate (over 450 times), and increased 855.9 fold in resistance as compared with susceptible strain (S). Cross resistance of bifenazate resistant (BR) strain to eight miticides was investigated. The BR strain exhibited high and low cross resistance to acequinocyl (614.0 fold) and to chlorfenapyr (9.1 fold), respectively. Against fenazaquin (0.3 fold) and fenpyroximate (0.1 fold), however, showed the strain negatively correlated cross resistance. Each strain collected in Choeng-ju (CJ), Kang-jin (KJ), and Chung-ju (CUJ) showed 5.5-, 964.5-, and 21.8-fold resistance to bifenazate, respectively. The detoxifying enzymes of the BR strain showed 1.6-fold activity in cytochrome $P_{450}$-dependent monooxygenase ($P_{450}$) as compared with susceptible one. By comparing the mitochondrial cytochrome b (cytb) sequence, G126S point mutation was detected in the BR and KJ strains.