• Title/Summary/Keyword: CYP

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Modulation of Biotransformation Enzymes by Phytochemicals: Impact of Genotypes

  • Lampe Johanna W.
    • Proceedings of the Korean Society of Food Science and Nutrition Conference
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    • 2004.11a
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    • pp.65-70
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    • 2004
  • Modulation of biotransformation enzymes is one mechanism by which a diet high in fruits and vegetable may influence cancer risk. Inhibition of cytochrome P450s (CYP) and concomitant induction of conjugating enzymes are hypothesized to reduce the impact of carcinogens in humans. Thus, exposure to types and amounts of phytochemicals may influence disease risk. Like other xenobiotics, many classes of phytochemicals are rapodly conjugated with glutathione, glucuronide, and sulfate moieties and excreted in urine and bile. In humans, circulating phytochemical levels very widely among individuals even in response to controlled dietary interventions. Polymorphisms in biotransformation enzymes, such as the glutathione S-transferases (GST), UDP-glucuronosyltransferases (UGT), and sulfotransferases (SULT), may ocntribute to the variability in phytochemical clearance and efficacy; polymorphic enzymes with lower enzyme activity prolong the half-lives of phytochmicals in vivo. Isothiocyanates (ITC) in cruciferous vegetables are catalyzed by the four major human GSTs: however reaction velocities of the enzymes differ greatly. In some observational studies of cancer, polymorphisms in the GSTMI and GSTTI genes that result in complete lack of GSTM1-1 protein, respectively, confer greater protection from cruciferous vegetable in individuals with these genotypes. Similarly, we have shown in a controlled dietary trial that levels of GST-alpha-induced by ITC-are higher in GSTMI-null individuals exposed to cruciferous vegetablse. The selectivity of glucuronosyl conjugation of flavonoids is dependent both on flavonoid structure as well as on the UGI isozyme involved in its conjuagtion. The effects of UGI polymorphisms on flavonoid clearnace have not been examind; but polymorphisms affect glucuronidation of several drugs. Given the strong interest in the chemopreventive effects of flavonoids, systematic evaluation of these polymorphic UGTs and flavonoid pharmacokinetics are warranted. Overall, these studies suggest that for phytochemicals that are metabolized by, and affect activity of, biotransformation enzymes, interactions between genetic polymorphisms in the enzymes and intake of the compounds should be considered in studies of cancer risk. Genetic polymorphisms in biotransformation enzymes may account in prat for individual variation in metabolism of a wide range of phytochemicals and their ultimate impact on health.

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Clinical Pharmacogenomics of Drug Metabolizing Enzymes and its Clinical Application (약물대사효소의 유전적 다형성 및 임상적 응용)

  • Kim, Kyung-Im;Kim, Seung-Hee;Park, Ji-Eun;Chae, Han-Jung;Choi, Ji-Sun;Shin, Wan-Gyun;Son, In-Ja;Oh, Jung-Mi
    • Korean Journal of Clinical Pharmacy
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    • v.16 no.2
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    • pp.155-164
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    • 2006
  • Great inter-variability in drug response and adverse drug reactions is related to inter-variability of drug bioavailability, drug interaction and patient's disease and physyological state that cause change in absorption, distribution, metabolism and excretion of drugs. However, these alone do not sufficiently predict and explain inter-variability in drug response. In recent studies, it is reported that inter-variability in drug response and adverse drug reactions may largely resulted from genetically determined differences in drug absoption, distribution, metabolism and drug target proteins. Especially, the major human drug-metabolizing enzymes such as CYP450, N-acetyl tranferase, thiopurine S-methyl transferase, glutathione S-transferase are identified as the major gene variants that cause inter-individual variability in drug's response and adverse drug reactions. These variations may have most significant implications for those drugs that have narrow therapeutic index and serious adverse drug reactions. Therefore, the genetic variation such as polymorphisms in drug metabolizing enzymes can affect the response of individuals to drugs that are used in the treatment of depression, psychosis, cancer, cardiovascular disorders, ulcer and gastrointestinal disorders, pain and epilepsy, among others. This review describes the pharmacogenomics of the drug metabolizing enzymes associated with the drug response and its clinical applications.

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Prescribing Patterns of Codeine among Children under Aged 12 in Korea (건강보험자료를 이용한 12세 미만 소아에서 코데인 처방양상평가)

  • Park, Hyo-Ju;Shin, Han-Na;Shin, Ju-Young
    • Korean Journal of Clinical Pharmacy
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    • v.25 no.4
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    • pp.273-279
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    • 2015
  • Objective: Codeine may result in death or respiratory depression in children, particularly who are rapid metabolizer of CYP2D6, therefore it should be used cautiously among children under 12 years of age. This study was to investigate the prescribing pattern of codeine among children according to the age group, prescribed diagnosis, type of medical service and medical specialties. Method: We used Korea Health Insurance Review and Assessment Service-National Patient Sample (HIRA-NPS) database. Study subjects included inpatients or outpatients, who were prescribed codeine between January, 1, 2011 and December, 31, 2011. Contraindicated use of codeine was defined as the use of codeine at least one times under aged 12. Age groups were subclassified according to the <2 years, 2-4 years, 5-8 years, and 9-11 years. Frequently prescribed diagnosis (ICD-10), type of medical service, and medical specialties were also described among codeine users under aged 12. Results: Codeine users were 6,411 inpatients (9,958 prescriptions), and 3,397 outpatients (6,258 prescriptions), respectively. Codeine prescription under 12 years of age were 2.1% (210 prescriptions) among inpatients, and 12.3% (776 prescriptions) among outpatients (p-value<0.05). Outpatient prescriptions of codeine under 12 aged were issued mostly from primary care clinics and frequent diagnosis were unspecified bronchopneumonia (51.6%), and vasomotor rhinitis (23.7%). Conclusion: This study found prescribing of codeine under 12 aged is common in outpatient and primary clinics. Nationwide and community-based efforts should be needed to reduce inappropriate prescribing among children.

Screening Differential Expressions of Defense-related Responses in Cold-treated 'Kyoho' and 'Campbell Early' Grapevines

  • Ahn, Soon Young;Kim, Seon Ae;Han, Jae Hyun;Kim, Seung Heui;Yun, Hae Keun
    • Horticultural Science & Technology
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    • v.31 no.3
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    • pp.275-281
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    • 2013
  • Low temperature is one of the major environmental factors that affect productivity including reduced growth and budding of vines, and changes of metabolic processes in grape (Vitis spp.). To screen the specific expression of abiotic stress-related genes against cold treatment in 'Kyoho' and 'Campbell Early' grapevines, expression of various defense-related genes was investigated by RT-PCR and real-time PCR. Among the 67 genes analyzed by RT-PCR and real-time PCR, 17 and 16 types of cDNA were up-regulated, while 5 and 6 types were down-regulated in cold-treated 'Kyoho' and 'Campbell Early' grapevines, respectively. Genes encoding carotene (Cart3564 and Cart4472), chalcone isomerase (CHI), cytochrome P450 (CYP), flavonol synthase (FLS), endo-${\beta}$-glucanase precursor (Glu), glutathione peroxidase (GPX), glutathione-S-transferase (GST), leucine-rich repeats (LRR), manganese superoxide dismutase (Mn-SOD), phenylalanine ammonia lyase (PAL), polygalacturonase-inhibiting protein (PGIP), proline rich protein 2 (PRP2), small heat shock protein (sHSP), temperature induced lipocalin (TIL), and thaumatin-like protein (TLP) were up-regulated, while those encoding CBF like transcription factor (CBF1), chitinase-like protein (CLP), cold induced protein (CIP), glycerol-3-phosphate acyltransferase (GPAT), and mitogen-activated protein kinase (MAPK) were down-regulated by low temperature treatment in both in 'Kyoho' and 'Campbell Early'.

Effects of Baicalin on Oral Pharmacokinetics of Caffeine in Rats

  • Noh, Keumhan;Nepal, Mahesh Raj;Jeong, Ki Sun;Kim, Sun-A;Um, Yeon Ji;Seo, Chae Shin;Kang, Mi Jeong;Park, Pil-Hoon;Kang, Wonku;Jeong, Hye Gwang;Jeong, Tae Cheon
    • Biomolecules & Therapeutics
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    • v.23 no.2
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    • pp.201-206
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    • 2015
  • Scutellaria baicalensis is one of the most widely used herbal medicines in East Asia. Because baicalein and baicalin are major components of this herb, it is important to understand the effects of these compounds on drug metabolizing enzymes, such as cytochrome P450 (CYP), for evaluating herb-drug interaction. The effects of baicalin and baicalein on activities of ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), benzyloxyresorufin O-debenzylase (BROD), p-nitrophenol hydroxylase and erythromycin N-demethylase were assessed in rat liver microsomes in the present study. In addition, the pharmacokinetics of caffeine and its three metabolites (i.e., paraxanthine, theobromine and theophylline) in baicalin-treated rats were compared with untreated control. As results, EROD, MROD and BROD activities were inhibited by both baicalin and baicalein. However, there were no significant differences in the pharmacokinetic parameters of oral caffeine and its three metabolites between control and baicalin-treated rats. When the plasma concentration of baicalin was determined, the maximum concentration of baicalin was below the estimated $IC_{50}$ values observed in vitro. In conclusion, baicalin had no effects on the pharmacokinetics of caffeine and its metabolites in vivo, following single oral administration in rats.

Surface Display of Heme- and Diflavin-Containing Cytochrome P450 BM3 in Escherichia coli: A Whole-Cell Biocatalyst for Oxidation

  • Yim, Sung-Kun;Kim, Dong-Hyun;Jung, Heung-Chae;Pan, Jae-Gu;Kang, Hyung-Sik;Ahn, Tae-Ho;Yun, Chul-Ho
    • Journal of Microbiology and Biotechnology
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    • v.20 no.4
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    • pp.712-717
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    • 2010
  • Cytochrome P450 enzymes (P450s) are involved in the synthesis of a wide variety of valuable products and in the degradation of numerous toxic compounds. The P450 BM3 (CYP102A1) from Bacillus megaterium was the first P450 discovered to be fused to its redox partner, a mammalian-like diflavin reductase. Here, we report the development of a whole-cell biocatalyst using ice-nucleation protein (Inp) from Pseudomonas syringae to display a hemeand diflavin-containing oxidoreductase, P450 BM3 (a single, 119-kDa polypeptide with domains of both an oxygenase and a reductase) on the surface of Escherichia coli. The surface localization and functionality of the fusion protein containing P450 BM3 were verified by flow cytometry and measurement of enzymatic activities. The results of this study comprise the first report of microbial cell-surface display of a heme- and diflavin-containing enzyme. This system should allow us to select and develop oxidoreductases containing heme and/or flavins into practically useful whole-cell biocatalysts for extensive biotechnological applications, including selective synthesis of new chemicals and pharmaceuticals, bioconversion, bioremediation, live vaccine development, and biochip development.

Effect of DDT on Testosterone Production by Modulator Aromatase (CYP 19) in R2C

  • Lee, Kyung-Jin;Lee, Jong-Bin;Jeong, Hye-Gwang
    • Korean Journal of Environmental Biology
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    • v.21 no.3
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    • pp.308-312
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    • 2003
  • Various pesticides known or suspected to interfere with steroid hormone function were screened toy effects in leydig cells on catalytic activity and mRNA expression of aromatase. Dichlorodiphenyltrichloroethane (DDT) is a widespread environmental pollutant. In this study, we investigated the effect of DDT on testosterone production through aromatase activity and its molecular mechanism in testicular leydig cell, R2C by using radioimmunoassay (RIA). As the results, the potent leydig: cell activator LH increased testosterone production compared to the control. DDT exposure significantly decreased testosterone production in R2C cell. In addition, DDT was found to increase aromatase gene expression and activity in R2C cell in a dose dependent manner. In order to assess whether the suppressive effects of DDT on LH-inducible testosterone (T) production might be influenced by the ER, ICI 182.780 was used, and it was found that these inhibitory effects of DDT were antagonized by ICI 182.780, implying that the estrogen receptor (ER) mediates the suppressive effects of DDT. Furthermore, the inducible effects of DDT on aromatase gene expression might be influenced by the ER, ICI 182.780 was used, and it was found that these enhancing effects of DDT were antagonized by ICI 182.780, implying that the ER mediates the inducible effects of DDT. Our results indicated that DDT inhibition of luteinizing hormone (LH) -inducible T production in R2C cell is mediated through aromatase. However, the precise mechanisms by which DDT enhance in R2C cell remains unknown. The current study suggests the possibility that DDT might act as a modulator aromatase gene transcription.

Review of Gender Differences in Medicine and Primary Factors Resulting in Gender Differences (의약품에서의 성별차이 및 유발요인)

  • Kim, Hyun-Ju;Choi, Jong-Min;Kim, You-Jin;Chae, Song-Wha;Park, Jung-Hyun;Oh, Ji-Hyun;Kim, Kyung-Hee;Heo, Jung-Sun;Gwak, Hye-Sun;Lee, Hwa-Jeong
    • Korean Journal of Clinical Pharmacy
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    • v.20 no.2
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    • pp.128-137
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    • 2010
  • This review summarizes gender differences in pharmacokinetics, pharmacodynamics, and adverse drug reactions. Gender differences in pharmacokinetics are categorized by four major factors: absorption/bioavailability, distribution, metabolism, and elimination. There are sex-based differences in gastric emptying time, gastric alcohol dehydrogenase activity, apparent volume of distribution, ${\alpha}1$-acid glycoprotein level, phase I (CYP) and phase II metabolizing enzymes, glomerular filtration rate, and drug transporters. This review also reports gender differences in pharmacokinetics and pharmacodynamics of cardiovascular agents, central nervous system acting agents and antiviral agents. In addition, it has been reported that females experience more adverse reactions such as coughing, tachycardia, nausea, vomiting, rash, hypersensitivity, hepatotoxicity, and metabolic disorder after taking cardiovascular, central nervous system acting and antiviral agents. Therefore, in order to provide optimal drug dosage regimens both in male and female, gender differences in pharmacokinetics, pharmacodynamics, and adverse drug reactions must be considered.

Effects of Biologically Active Substances in Natural Products on the Hepatic Detoxication Mechanism (천연물중의 생리활성성분이 간해독기구에 미치는 영향)

  • 권정숙
    • Journal of Nutrition and Health
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    • v.27 no.4
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    • pp.347-355
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    • 1994
  • Indolo[3,2-b]carbazole(ICZ) is a potent Ah receptor agonist with biological activities similar in several respects to those of the potent environmental toxin, TCDD. ICZ is produced during the oilgomerization of indole-3-carbinol(I3C), a breakdown product of the glucobrassicin present in food plants of the Brassica genus. In the present study we examined ICZ levels in tissues and excreta of rats treated with I3C or dietary cabbage of established glucobrasicin content, and in feces of conventional and germfree rats fed on a basal diet, and of humans. We also examined the levels of cytochrome P4501A1 induction, as determined by the ethoxyresorufin ο-deethylase assay, in tissues of animals that received cabbage-supplemented diets, or which were treated with purified I3C or ICZ. Our findings indicated that incorporation of either homogenized or whole freeze-dried cabbage in the feed led to large increases(16-60 fold) in the levels of ICZ in the feces and lower gastrointestinal tract of rats. We observed that whereas ICZ is readily detectable at about the same levels(2.00$\pm$0.50 ppb) in the feces of conventional rats fed on a purified diet and in human feces, levels of ICZ in the feces of germfree animals fed on the basal diet were at the limits of detection(0.40$\pm$0.20 ppb), indication that gut bacteria are important for the production of ICZ from essential dietary constituents in the basal diet. We showed that in contrast to the near 7000-fold difference in CYP1A1 inducing potencies of ICZ and TCDD in cells in culture, their inducing potencies differ by only about an order of magnitude in rats. Nonetheless, the levels of ICZ remaining in livers twenty hours after I3C treatment appear too low to account for the induced activity. This result indicates that ICZ may be rapidly cleared from the liver or that substances other than, or in addition to, ICZ be responsible for the enzyme-inducing activity of orally administered I3C or its precursors.

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Identification of interacting proteins of retinoid-related orphan nuclear receptor gamma in HepG2 cells

  • Huang, Ze-Min;Wu, Jun;Jia, Zheng-Cai;Tian, Yi;Tang, Jun;Tang, Yan;Wang, Ying;Wu, Yu-Zhang;Ni, Bing
    • BMB Reports
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    • v.45 no.6
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    • pp.331-336
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    • 2012
  • The retinoid-related orphan nuclear receptor gamma ($ROR{\gamma}$) plays critical roles in regulation of development, immunity and metabolism. As transcription factor usually forms a protein complex to function, thus capturing and dissecting of the $ROR{\gamma}$ protein complex will be helpful for exploring the mechanisms underlying those functions. After construction of the recombinant tandem affinity purification (TAP) plasmid, pMSCVpuro $ROR{\gamma}$-CTAP(SG), the nuclear localization of $ROR{\gamma}$-CTAP(SG) fusion protein was verified. Following isolation of $ROR{\gamma}$ protein complex by TAP strategy, seven candidate interacting proteins were identified. Finally, the heat shock protein 90 (HSP90) and receptor-interacting protein 140 (RIP140) were confirmed to interplay with $ROR{\gamma}$ by co-immunoprecipitation. Interference of HSP90 or/and RIP140 genes resulted in dramatically decreased expression of CYP2C8 gene, the $ROR{\gamma}$ target gene. Data from this study demonstrate that HSP90 and RIP140 proteins interact with $ROR{\gamma}$ protein in a complex format and function as co-activators in the $ROR{\gamma}$-mediated regulatory processes of HepG2 cells.