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Sample records for human drug metabolism

  1. Human drug metabolism: an introduction

    National Research Council Canada - National Science Library

    Coleman, Michael D

    2010-01-01

    Human Drug Metabolism, An Introduction, Second Edition provides an accessible introduction to the subject and will be particularly invaluable to those who already have some understanding of the life sciences...

  2. Human drug metabolism: an introduction

    National Research Council Canada - National Science Library

    Coleman, Michael D

    2010-01-01

    ..., both under drug pressure and during inhibition. Factors affecting drug metabolism, such as genetic polymorphisms, age and diet are discussed and how metabolism can lead to toxicity is explained. The book concludes with the role of drug metabolism in the commercial development of therapeutic agents as well as the pharmacology of some illicit drugs.

  3. Human drug metabolism: an introduction

    National Research Council Canada - National Science Library

    Coleman, Michael D

    2010-01-01

    ... metabolism and its impact on patient welfare. After underlining the relationship between efficacy, toxicity and drug concentration, the book then considers how metabolizing systems operate and how they impact upon drug concentration...

  4. Human drug metabolism: an introduction

    National Research Council Canada - National Science Library

    Coleman, Michael D

    2010-01-01

    .... Completely revised and updated throughout, the new edition focuses only on essential chemical detail and includes patient case histories to illustrate the clinical consequences of changes in drug...

  5. In Vitro Drug Metabolism by Human Carboxylesterase 1

    DEFF Research Database (Denmark)

    Thomsen, Ragnar; Rasmussen, Henrik B; Linnet, Kristian

    2014-01-01

    Carboxylesterase 1 (CES1) is the major hydrolase in human liver. The enzyme is involved in the metabolism of several important therapeutic agents, drugs of abuse, and endogenous compounds. However, no studies have described the role of human CES1 in the activation of two commonly prescribed...... a panel of therapeutic drugs and drugs of abuse to assess their inhibition of the hydrolysis of p-nitrophenyl acetate by recombinant CES1 and human liver microsomes. The screening assay confirmed several known inhibitors of CES1 and identified two previously unreported inhibitors: the dihydropyridine...... calcium antagonist, isradipine, and the immunosuppressive agent, tacrolimus. CES1 plays a role in the metabolism of several drugs used in the treatment of common conditions, including hypertension, congestive heart failure, and diabetes mellitus; thus, there is a potential for clinically relevant drug-drug...

  6. Chimeric mice with humanized liver: Application in drug metabolism and pharmacokinetics studies for drug discovery.

    Science.gov (United States)

    Naritomi, Yoichi; Sanoh, Seigo; Ohta, Shigeru

    2018-02-01

    Predicting human drug metabolism and pharmacokinetics (PK) is key to drug discovery. In particular, it is important to predict human PK, metabolite profiles and drug-drug interactions (DDIs). Various methods have been used for such predictions, including in vitro metabolic studies using human biological samples, such as hepatic microsomes and hepatocytes, and in vivo studies using experimental animals. However, prediction studies using these methods are often inconclusive due to discrepancies between in vitro and in vivo results, and interspecies differences in drug metabolism. Further, the prediction methods have changed from qualitative to quantitative to solve these issues. Chimeric mice with humanized liver have been developed, in which mouse liver cells are mostly replaced with human hepatocytes. Since human drug metabolizing enzymes are expressed in the liver of these mice, they are regarded as suitable models for mimicking the drug metabolism and PK observed in humans; therefore, these mice are useful for predicting human drug metabolism and PK. In this review, we discuss the current state, issues, and future directions of predicting human drug metabolism and PK using chimeric mice with humanized liver in drug discovery. Copyright © 2017 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  7. Cunninghamella Biotransformation--Similarities to Human Drug Metabolism and Its Relevance for the Drug Discovery Process.

    Science.gov (United States)

    Piska, Kamil; Żelaszczyk, Dorota; Jamrozik, Marek; Kubowicz-Kwaśny, Paulina; Pękala, Elżbieta

    2016-01-01

    Studies of drug metabolism are one of the most significant issues in the process of drug development, its introduction to the market and also in treatment. Even the most promising molecule may show undesirable metabolic properties that would disqualify it as a potential drug. Therefore, such studies are conducted in the early phases of drug discovery and development process. Cunninghamella is a filamentous fungus known for its catalytic properties, which mimics mammalian drug metabolism. It has been proven that C. elegans carries at least one gene coding for a CYP enzyme closely related to the CYP51 family. The transformation profile of xenobiotics in Cunninghamella spp. spans a number of reactions catalyzed by different mammalian CYP isoforms. This paper presents detailed data on similar biotransformation drug products in humans and Cunninghamella spp. and covers the most important aspects of preparative biosynthesis of metabolites, since this model allows to obtain metabolites in sufficient quantities to conduct the further detailed investigations, as quantification, structure analysis and pharmacological activity and toxicity testing. The metabolic activity of three mostly used Cunninghamella species in obtaining hydroxylated, dealkylated and oxidated metabolites of different drugs confirmed its convergence with human biotransformation. Though it cannot replace the standard methods, it can provide support in the field of biotransformation and identifying metabolic soft spots of new chemicals and in predicting possible metabolic pathways. Another aspect is the biosynthesis of metabolites. In this respect, techniques using Cunninghamella spp. seem to be competitive to the chemical methods currently used.

  8. Application of chimeric mice with humanized liver for study of human-specific drug metabolism.

    Science.gov (United States)

    Bateman, Thomas J; Reddy, Vijay G B; Kakuni, Masakazu; Morikawa, Yoshio; Kumar, Sanjeev

    2014-06-01

    Human-specific or disproportionately abundant human metabolites of drug candidates that are not adequately formed and qualified in preclinical safety assessment species pose an important drug development challenge. Furthermore, the overall metabolic profile of drug candidates in humans is an important determinant of their drug-drug interaction susceptibility. These risks can be effectively assessed and/or mitigated if human metabolic profile of the drug candidate could reliably be determined in early development. However, currently available in vitro human models (e.g., liver microsomes, hepatocytes) are often inadequate in this regard. Furthermore, the conduct of definitive radiolabeled human ADME studies is an expensive and time-consuming endeavor that is more suited for later in development when the risk of failure has been reduced. We evaluated a recently developed chimeric mouse model with humanized liver on uPA/SCID background for its ability to predict human disposition of four model drugs (lamotrigine, diclofenac, MRK-A, and propafenone) that are known to exhibit human-specific metabolism. The results from these studies demonstrate that chimeric mice were able to reproduce the human-specific metabolite profile for lamotrigine, diclofenac, and MRK-A. In the case of propafenone, however, the human-specific metabolism was not detected as a predominant pathway, and the metabolite profiles in native and humanized mice were similar; this was attributed to the presence of residual highly active propafenone-metabolizing mouse enzymes in chimeric mice. Overall, the data indicate that the chimeric mice with humanized liver have the potential to be a useful tool for the prediction of human-specific metabolism of xenobiotics and warrant further investigation.

  9. Drug Metabolism

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 3. Drug Metabolism: A Fascinating Link Between Chemistry and Biology. Nikhil Taxak Prasad V Bharatam. General Article Volume 19 Issue 3 March 2014 pp 259-282 ...

  10. Drug Metabolism

    Indian Academy of Sciences (India)

    IAS Admin

    behind metabolic reactions, importance, and consequences with several ... required for drug action. ... lism, which is catalyzed by enzymes present in the above-men- ... catalyze the transfer of one atom of oxygen to a substrate produc-.

  11. Short-term fasting alters cytochrome P450-mediated drug metabolism in humans

    NARCIS (Netherlands)

    Lammers, Laureen A.; Achterbergh, Roos; de Vries, Emmely M.; van Nierop, F. Samuel; Klümpen, Heinz-Josef; Soeters, Maarten R.; Boelen, Anita; Romijn, Johannes A.; Mathôt, Ron A. A.

    2015-01-01

    Experimental studies indicate that short-term fasting alters drug metabolism. However, the effects of short-term fasting on drug metabolism in humans need further investigation. Therefore, the aim of this study was to evaluate the effects of short-term fasting (36 h) on P450-mediated drug

  12. Expression and Regulation of Drug Transporters and Metabolizing Enzymes in the Human Gastrointestinal Tract.

    Science.gov (United States)

    Drozdzik, M; Oswald, S

    2016-01-01

    Orally administered drugs must pass through the intestinal wall and then through the liver before reaching systemic circulation. During this process drugs are subjected to different processes that may determine the therapeutic value. The intestinal barrier with active drug metabolizing enzymes and drug transporters in enterocytes plays an important role in the determination of drug bioavailability. Accumulating information demonstrates variable distribution of drug metabolizing enzymes and transporters along the human gastrointestinal tract (GI), that creates specific barrier characteristics in different segments of the GI. In this review, expression of drug metabolizing enzymes and transporters in the healthy and diseased human GI as well as their regulatory aspects: genetic, miRNA, DNA methylation are outlined. The knowledge of unique interplay between drug metabolizing enzymes and transporters in specific segments of the GI tract allows more precise definition of drug release sites within the GI in order to assure more complete bioavailability and prediction of drug interactions.

  13. DrugMetZ DB: an anthology of human drug metabolizing Chytochrome P450 enzymes.

    Science.gov (United States)

    Antony, Tresa Remya Thomas; Nagarajan, Shanthi

    2006-11-14

    Understandings the basics of Cytochrome P450 (P450 or CYP) will help to discern drug metabolism. CYP, a super-family of heme-thiolate proteins, are found in almost all living organisms and is involved in the biotransformation of a diverse range of xenobiotics, therapeutic drugs and toxins. Here, we describe DrugMetZ DB, a database for CYP metabolizing drugs. The DB is implemented in MySQL, PHP and HTML. www.bicpu.edu.in/DrugMetZDB/

  14. Chemical reaction vector embeddings: towards predicting drug metabolism in the human gut microbiome.

    Science.gov (United States)

    Mallory, Emily K; Acharya, Ambika; Rensi, Stefano E; Turnbaugh, Peter J; Bright, Roselie A; Altman, Russ B

    2018-01-01

    Bacteria in the human gut have the ability to activate, inactivate, and reactivate drugs with both intended and unintended effects. For example, the drug digoxin is reduced to the inactive metabolite dihydrodigoxin by the gut Actinobacterium E. lenta, and patients colonized with high levels of drug metabolizing strains may have limited response to the drug. Understanding the complete space of drugs that are metabolized by the human gut microbiome is critical for predicting bacteria-drug relationships and their effects on individual patient response. Discovery and validation of drug metabolism via bacterial enzymes has yielded >50 drugs after nearly a century of experimental research. However, there are limited computational tools for screening drugs for potential metabolism by the gut microbiome. We developed a pipeline for comparing and characterizing chemical transformations using continuous vector representations of molecular structure learned using unsupervised representation learning. We applied this pipeline to chemical reaction data from MetaCyc to characterize the utility of vector representations for chemical reaction transformations. After clustering molecular and reaction vectors, we performed enrichment analyses and queries to characterize the space. We detected enriched enzyme names, Gene Ontology terms, and Enzyme Consortium (EC) classes within reaction clusters. In addition, we queried reactions against drug-metabolite transformations known to be metabolized by the human gut microbiome. The top results for these known drug transformations contained similar substructure modifications to the original drug pair. This work enables high throughput screening of drugs and their resulting metabolites against chemical reactions common to gut bacteria.

  15. Drug metabolism in human brain: high levels of cytochrome P4503A43 in brain and metabolism of anti-anxiety drug alprazolam to its active metabolite.

    Directory of Open Access Journals (Sweden)

    Varsha Agarwal

    2008-06-01

    Full Text Available Cytochrome P450 (P450 is a super-family of drug metabolizing enzymes. P450 enzymes have dual function; they can metabolize drugs to pharmacologically inactive metabolites facilitating their excretion or biotransform them to pharmacologically active metabolites which may have longer half-life than the parent drug. The variable pharmacological response to psychoactive drugs typically seen in population groups is often not accountable by considering dissimilarities in hepatic metabolism. Metabolism in brain specific nuclei may play a role in pharmacological modulation of drugs acting on the CNS and help explain some of the diverse response to these drugs seen in patient population. P450 enzymes are also present in brain where drug metabolism can take place and modify therapeutic action of drugs at the site of action. We have earlier demonstrated an intrinsic difference in the biotransformation of alprazolam (ALP in brain and liver, relatively more alpha-hydroxy alprazolam (alpha-OHALP is formed in brain as compared to liver. In the present study we show that recombinant CYP3A43 metabolizes ALP to both alpha-OHALP and 4-hydroxy alprazolam (4-OHALP while CYP3A4 metabolizes ALP predominantly to its inactive metabolite, 4-OHALP. The expression of CYP3A43 mRNA in human brain samples correlates with formation of relatively higher levels of alpha-OH ALP indicating that individuals who express higher levels of CYP3A43 in the brain would generate larger amounts of alpha-OHALP. Further, the expression of CYP3A43 was relatively higher in brain as compared to liver across different ethnic populations. Since CYP3A enzymes play a prominent role in the metabolism of drugs, the higher expression of CYP3A43 would generate metabolite profile of drugs differentially in human brain and thus impact the pharmacodynamics of psychoactive drugs at the site of action.

  16. Innovative methods to study human intestinal drug metabolism in vitro : Precision-cut slices compared with Ussing chamber preparations

    NARCIS (Netherlands)

    van de Kerkhof, Esther G.; Ungell, Anna-Lena B.; Sjoberg, Asa K.; de Jager, Marina H.; Hilgendorf, Constanze; de Graaf, Inge A. M.; Groothuis, Geny M. M.

    2006-01-01

    Predictive in vitro methods to investigate drug metabolism in the human intestine using intact tissue are of high importance. Therefore, we studied the metabolic activity of human small intestinal and colon slices and compared it with the metabolic activity of the same human intestinal segments

  17. Chimeric mice transplanted with human hepatocytes as a model for prediction of human drug metabolism and pharmacokinetics.

    Science.gov (United States)

    Sanoh, Seigo; Ohta, Shigeru

    2014-03-01

    Preclinical studies in animal models are used routinely during drug development, but species differences of pharmacokinetics (PK) between animals and humans have to be taken into account in interpreting the results. Human hepatocytes are also widely used to examine metabolic activities mediated by cytochrome P450 (P450) and other enzymes, but such in vitro metabolic studies also have limitations. Recently, chimeric mice with humanized liver (h-chimeric mice), generated by transplantation of human donor hepatocytes, have been developed as a model for the prediction of metabolism and PK in humans, using both in vitro and in vivo approaches. The expression of human-specific metabolic enzymes and metabolic activities was confirmed in humanized liver of h-chimeric mice with high replacement ratios, and several reports indicate that the profiles of P450 and non-P450 metabolism in these mice adequately reflect those in humans. Further, the combined use of h-chimeric mice and r-chimeric mice, in which endogenous hepatocytes are replaced with rat hepatocytes, is a promising approach for evaluation of species differences in drug metabolism. Recent work has shown that data obtained in h-chimeric mice enable the semi-quantitative prediction of not only metabolites, but also PK parameters, such as hepatic clearance, of drug candidates in humans, although some limitations remain because of differences in the metabolic activities, hepatic blood flow and liver structure between humans and mice. In addition, fresh h-hepatocytes can be isolated reproducibly from h-chimeric mice for metabolic studies. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Metabolic activity and mRNA levels of human cardiac CYP450s involved in drug metabolism.

    Directory of Open Access Journals (Sweden)

    Veronique Michaud

    2010-12-01

    Full Text Available Tissue-specific expression of CYP450s can regulate the intracellular concentration of drugs and explain inter-subject variability in drug action. The overall objective of our study was to determine in a large cohort of samples, mRNA levels and CYP450 activity expressed in the human heart.CYP450 mRNA levels were determined by RTPCR in left ventricular samples (n = 68 of explanted hearts from patients with end-stage heart failure. Samples were obtained from ischemic and non-ischemic hearts. In some instances (n = 7, samples were available from both the left and right ventricles. A technique for the preparation of microsomes from human heart tissue was developed and CYP450-dependent activity was determined using verapamil enantiomers as probe-drug substrates.Our results show that CYP2J2 mRNA was the most abundant isoform in all human heart left ventricular samples tested. Other CYP450 mRNAs of importance were CYP4A11, CYP2E1, CYP1A1 and CYP2C8 mRNAs while CYP2B6 and CYP2C9 mRNAs were present at low levels in only some of the hearts analyzed. CYP450 mRNAs did not differ between ischemic and non-ischemic hearts and appeared to be present at similar levels in the left and right ventricles. Incubation of verapamil with heart microsomes led to the formation of nine CYP450-dependent metabolites: a major finding was the observation that stereoselectivity was reversed compared to human liver microsomes, in which the R-enantiomer is metabolized to a greater extent.This study determined cardiac mRNA levels of various CYP450 isozymes involved in drug metabolism and demonstrated the prevalent expression of CYP2J2 mRNA. It revealed that cardiomyocytes can efficiently metabolize drugs and that cardiac CYP450s are highly relevant with regard to clearance of drugs in the heart. Our results support the claim that drug metabolism in the vicinity of a drug effector site can modulate drug effects.

  19. Gene expression variability in human hepatic drug metabolizing enzymes and transporters.

    Directory of Open Access Journals (Sweden)

    Lun Yang

    Full Text Available Interindividual variability in the expression of drug-metabolizing enzymes and transporters (DMETs in human liver may contribute to interindividual differences in drug efficacy and adverse reactions. Published studies that analyzed variability in the expression of DMET genes were limited by sample sizes and the number of genes profiled. We systematically analyzed the expression of 374 DMETs from a microarray data set consisting of gene expression profiles derived from 427 human liver samples. The standard deviation of interindividual expression for DMET genes was much higher than that for non-DMET genes. The 20 DMET genes with the largest variability in the expression provided examples of the interindividual variation. Gene expression data were also analyzed using network analysis methods, which delineates the similarities of biological functionalities and regulation mechanisms for these highly variable DMET genes. Expression variability of human hepatic DMET genes may affect drug-gene interactions and disease susceptibility, with concomitant clinical implications.

  20. Human gut microbiota plays a role in the metabolism of drugs.

    Science.gov (United States)

    Jourova, Lenka; Anzenbacher, Pavel; Anzenbacherova, Eva

    2016-09-01

    The gut microbiome, an aggregate genome of trillions of microorganisms residing in the human gastrointestinal tract, is now known to play a critical role in human health and predisposition to disease. It is also involved in the biotransformation of xenobiotics and several recent studies have shown that the gut microbiota can affect the pharmacokinetics of orally taken drugs with implications for their oral bioavailability. Review of Pubmed, Web of Science and Science Direct databases for the years 1957-2016. Recent studies make it clear that the human gut microbiota can play a major role in the metabolism of xenobiotics and, the stability and oral bioavailability of drugs. Over the past 50 years, more than 30 drugs have been identified as a substrate for intestinal bacteria. Questions concerning the impact of the gut microbiota on drug metabolism, remain unanswered or only partially answered, namely (i) what are the molecular mechanisms and which bacterial species are involved? (ii) What is the impact of host genotype and environmental factors on the composition and function of the gut microbiota, (iii) To what extent is the composition of the intestinal microbiome stable, transmissible, and resilient to perturbation? (iv) Has past exposure to a given drug any impact on future microbial response, and, if so, for how long? Answering such questions should be an integral part of pharmaceutical research and personalised health care.

  1. Comparison of minipig, dog, monkey and human drug metabolism and disposition.

    Science.gov (United States)

    Dalgaard, Lars

    2015-01-01

    This article gives an overview of the drug metabolism and disposition (ADME) characteristics of the most common non-rodent species used in toxicity testing of drugs (minipigs, dogs, and monkeys) and compares these to human characteristics with regard to enzymes mediating the metabolism of drugs and the transport proteins which contribute to the absorption, distribution and excretion of drugs. Literature on ADME and regulatory guidelines of relevance in drug development of small molecules has been gathered. Non-human primates (monkeys) are the species that is closest to humans in terms of genetic homology. Dogs have an advantage due to the ready availability of comprehensive background data for toxicological safety assessment and dogs are easy to handle. Pigs have been used less than dogs and monkeys as a model in safety assessment of drug candidates. However, when a drug candidate is metabolised by aldehyde oxidase (AOX1), N-acetyltransferases (NAT1 and NAT2) or cytochrome (CYP2C9-like) enzymes which are not expressed in dogs, but are present in pigs, this species may be a better choice than dogs, provided that adequate exposure can be obtained in pigs. Conversely, pigs might not be the right choice if sulfation, involving 3-phospho-adenosyl-5-phosphosulphate sulphotransferase (PAPS) is an important pathway in the human metabolism of a drug candidate. In general, the species selection should be based on comparison between in vitro studies with human cell-based systems and animal-cell-based systems. Results from pharmacokinetic studies are also important for decision-making by establishing the obtainable exposure level in the species. Access to genetically humanized mouse models and highly sensitive analytical methods (accelerator mass spectrometry) makes it possible to improve the chance of finding all metabolites relevant for humans before clinical trials have been initiated and, if necessary, to include another animal species before long term toxicity studies are

  2. Recellularization of rat liver: An in vitro model for assessing human drug metabolism and liver biology.

    Directory of Open Access Journals (Sweden)

    Matthew J Robertson

    Full Text Available Liver-like organoids that recapitulate the complex functions of the whole liver by combining cells, scaffolds, and mechanical or chemical cues are becoming important models for studying liver biology and drug metabolism. The advantages of growing cells in three-dimensional constructs include enhanced cell-cell and cell-extracellular matrix interactions and preserved cellular phenotype including, prevention of de-differentiation. In the current study, biomimetic liver constructs were made via perfusion decellularization of rat liver, with the goal of maintaining the native composition and structure of the extracellular matrix. We optimized our decellularization process to produce liver scaffolds in which immunogenic residual DNA was removed but glycosaminoglycans were maintained. When the constructs were recellularized with rat or human liver cells, the cells remained viable, capable of proliferation, and functional for 28 days. Specifically, the cells continued to express cytochrome P450 genes and maintained their ability to metabolize a model drug, midazolam. Microarray analysis showed an upregulation of genes involved in liver regeneration and fibrosis. In conclusion, these liver constructs have the potential to be used as test beds for studying liver biology and drug metabolism.

  3. The Ussing Chamber Assay to Study Drug Metabolism and Transport in the Human Intestine.

    Science.gov (United States)

    Kisser, Beatrice; Mangelsen, Eva; Wingolf, Caroline; Partecke, Lars Ivo; Heidecke, Claus-Dieter; Tannergren, Christer; Oswald, Stefan; Keiser, Markus

    2017-06-22

    The Ussing chamber is an old but still powerful technique originally designed to study the vectorial transport of ions through frog skin. This technique is also used to investigate the transport of chemical agents through the intestinal barrier as well as drug metabolism in enterocytes, both of which are key determinants for the bioavailability of orally administered drugs. More contemporary model systems, such as Caco-2 cell monolayers or stably transfected cells, are more limited in their use compared to the Ussing chamber because of differences in expression rates of transporter proteins and/or metabolizing enzymes. While there are limitations to the Ussing chamber assay, the use of human intestinal tissue remains the best laboratory test for characterizing the transport and metabolism of compounds following oral administration. Detailed in this unit is a step-by-step protocol for preparing human intestinal tissue, for designing Ussing chamber experiments, and for analyzing and interpreting the findings. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  4. Modulation of trichloroethylene in vitro metabolism by different drugs in human.

    Science.gov (United States)

    Cheikh Rouhou, Mouna; Haddad, Sami

    2014-08-01

    Toxicological interactions with drugs have the potential to modulate the toxicity of trichloroethylene (TCE). Our objective is to identify metabolic interactions between TCE and 14 widely used drugs in human suspended hepatocytes and characterize the strongest using microsomal assays. Changes in concentrations of TCE and its metabolites were measured by headspace GC-MS. Results with hepatocytes show that amoxicillin, cimetidine, ibuprofen, mefenamic acid and ranitidine caused no significant interactions. Naproxen and salicylic acid showed to increase both TCE metabolites levels, whereas acetaminophen, carbamazepine and erythromycin rather decreased them. Finally, diclofenac, gliclazide, sulphasalazine and valproic acid had an impact on the levels of only one metabolite. Among the 14 tested drugs, 5 presented the most potent interactions and were selected for confirmation with microsomes, namely naproxen, salicylic acid, acetaminophen, carbamazepine and valproic acid. Characterization in human microsomes confirmed interaction with naproxen by competitively inhibiting trichloroethanol (TCOH) glucuronidation (Ki=2.329 mM). Inhibition of TCOH formation was also confirmed for carbamazepine (partial non-competitive with Ki=70 μM). Interactions with human microsomes were not observed with salicylic acid and acetaminophen, similar to prior results in rat material. For valproic acid, interactions with microsomes were observed in rat but not in human. Inhibition patterns were shown to be similar in human and rat hepatocytes, but some differences in mechanisms were noted in microsomal material between species. Next research efforts will focus on determining the adequacy between in vitro observations and the in vivo situation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Drug metabolism in birds

    Science.gov (United States)

    Pan, Huo Ping; Fouts, James R.

    1979-01-01

    Papers published over 100 years since the beginning of the scientific study of drug metabolism in birds were reviewed. Birds were found to be able to accomplish more than 20 general biotransformation reactions in both functionalization and conjugation. Chickens were the primary subject of study but over 30 species of birds were used. Large species differences in drug metabolism exist between birds and mammals as well as between various birds, these differences were mostly quantitative. Qualitative differences were rare. On the whole, drug metabolism studies in birds have been neglected as compared with similar studies on insects and mammals. The uniqueness of birds and the advantages of using birds in drug metabolism studies are discussed. Possible future studies of drug metabolism in birds are recommended.

  6. Effect of honokiol on the induction of drug-metabolizing enzymes in human hepatocytes

    Directory of Open Access Journals (Sweden)

    Cho YY

    2014-11-01

    Full Text Available Yong-Yeon Cho,1 Hyeon-Uk Jeong,1 Jeong-Han Kim,2 Hye Suk Lee1 1College of Pharmacy, The Catholic University of Korea, Bucheon, Korea; 2Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea Abstract: Honokiol, 2-(4-hydroxy-3-prop-2-enyl-phenyl-4-prop-2-enyl-phenol, an active component of Magnolia officinalis and Magnolia grandiflora, exerts various pharmacological activities such as antitumorigenic, antioxidative, anti-inflammatory, neurotrophic, and antithrombotic effects. To investigate whether honokiol acts as a perpetrator in drug interactions, messenger ribonucleic acid (mRNA levels of phase I and II drug-metabolizing enzymes, including cytochrome P450 (CYP, UDP-glucuronosyltransferase (UGT, and sulfotransferase 2A1 (SULT2A1, were analyzed by real-time reverse transcription polymerase chain reaction following 48-hour honokiol exposure in three independent cryopreserved human hepatocyte cultures. Honokiol treatment at the highest concentration tested (50 µM increased the CYP2B6 mRNA level and CYP2B6-catalyzed bupropion hydroxylase activity more than two-fold in three different hepatocyte cultures, indicating that honokiol induces CYP2B6 at higher concentrations. However, honokiol treatment (0.5–50 µM did not significantly alter the mRNA levels of phase I enzymes (CYP1A2, CYP3A4, CYP2C8, CYP2C9, and CYP2C19 or phase II enzymes (UGT1A1, UGT1A4, UGT1A9, UGT2B7, and SULT2A1 in cryopreserved human hepatocyte cultures. CYP1A2-catalyzed phenacetin O-deethylase and CYP3A4-catalyzed midazolam 1'-hydroxylase activities were not affected by 48-hour honokiol treatment in cryopreserved human hepatocytes. These results indicate that honokiol is a weak CYP2B6 inducer and is unlikely to increase the metabolism of concomitant CYP2B6 substrates and cause pharmacokinetic-based drug interactions in humans. Keywords: honokiol, human hepatocytes, drug interactions, cytochrome P450, UDP-glucuronosyltransferases

  7. Expression Profile of Genes Related to Drug Metabolism in Human Brain Tumors.

    Directory of Open Access Journals (Sweden)

    Pantelis Stavrinou

    Full Text Available Endogenous and exogenous compounds as well as carcinogens are metabolized and detoxified by phase I and II enzymes, the activity of which could be crucial to the inactivation and hence susceptibility to carcinogenic factors. The expression of these enzymes in human brain tumor tissue has not been investigated sufficiently. We studied the association between tumor pathology and the expression profile of seven phase I and II drug metabolizing genes (CYP1A1, CYP1B1, ALDH3A1, AOX1, GSTP1, GSTT1 and GSTM3 and some of their proteins.Using qRT-PCR and western blotting analysis the gene and protein expression in a cohort of 77 tumors were investigated. The major tumor subtypes were meningioma, astrocytoma and brain metastases, -the later all adenocarcinomas from a lung primary.Meningeal tumors showed higher expression levels for AOX1, CYP1B1, GSTM3 and GSTP1. For AOX1, GSTM and GSTP1 this could be verified on a protein level as well. A negative correlation between the WHO degree of malignancy and the strength of expression was identified on both transcriptional and translational level for AOX1, GSTM3 and GSTP1, although the results could have been biased by the prevalence of meningiomas and glioblastomas in the inevitably bipolar distribution of the WHO grades. A correlation between the gene expression and the protein product was observed for AOX1, GSTP1 and GSTM3 in astrocytomas.The various CNS tumors show different patterns of drug metabolizing gene expression. Our results suggest that the most important factor governing the expression of these enzymes is the histological subtype and to a far lesser extent the degree of malignancy itself.

  8. Microfluidics Enables Small-Scale Tissue-Based Drug Metabolism Studies With Scarce Human Tissue

    NARCIS (Netherlands)

    van Midwoud, Paul M.; Verpoorte, Elisabeth; Groothuis, Geny M. M.; Merema, M.T.

    2011-01-01

    Early information on the metabolism and toxicity properties of new drug candidates is crucial for selecting the right candidates for further development. Preclinical trials rely on cell-based in vitro tests and animal studies to characterize the in vivo behavior of drug candidates, although neither

  9. Current knowledge of microRNA-mediated regulation of drug metabolism in humans.

    Science.gov (United States)

    Nakano, Masataka; Nakajima, Miki

    2018-05-01

    Understanding the factors causing inter- and intra-individual differences in drug metabolism potencies is required for the practice of personalized or precision medicine, as well as for the promotion of efficient drug development. The expression of drug-metabolizing enzymes is controlled by transcriptional regulation by nuclear receptors and transcriptional factors, epigenetic regulation, such as DNA methylation and histone acetylation, and post-translational modification. In addition to such regulation mechanisms, recent studies revealed that microRNAs (miRNAs), endogenous ~22-nucleotide non-coding RNAs that regulate gene expression through the translational repression and degradation of mRNAs, significantly contribute to post-transcriptional regulation of drug-metabolizing enzymes. Areas covered: This review summarizes the current knowledge regarding miRNAs-dependent regulation of drug-metabolizing enzymes and transcriptional factors and its physiological and clinical significance. We also describe recent advances in miRNA-dependent regulation research, showing that the presence of pseudogenes, single-nucleotide polymorphisms, and RNA editing affects miRNA targeting. Expert opinion: It is unwavering fact that miRNAs are critical factors causing inter- and intra-individual differences in the expression of drug-metabolizing enzymes. Consideration of miRNA-dependent regulation would be a helpful tool for optimizing personalized and precision medicine.

  10. Drug metabolism and ageing.

    Science.gov (United States)

    Wynne, Hilary

    2005-06-01

    Older people are major consumers of drugs and because of this, as well as co-morbidity and age-related changes in pharmacokinetics and pharmacodynamics, are at risk of associated adverse drug reactions. While age does not alter drug absorption in a clinically significant way, and age-related changes in volume of drug distribution and protein binding are not of concern in chronic therapy, reduction in hepatic drug clearance is clinically important. Liver blood flow falls by about 35% between young adulthood and old age, and liver size by about 24-35% over the same period. First-pass metabolism of oral drugs avidly cleared by the liver and clearance of capacity-limited hepatically metabolized drugs fall in parallel with the fall in liver size, and clearance of drugs with a high hepatic extraction ratio falls in parallel with the fall in hepatic blood flow. In normal ageing, in general, activity of the cytochrome P450 enzymes is preserved, although a decline in frail older people has been noted, as well as in association with liver disease, cancer, trauma, sepsis, critical illness and renal failure. As the contribution of age, co-morbidity and concurrent drug therapy to altered drug clearance is impossible to predict in an individual older patient, it is wise to start any drug at a low dose and increase this slowly, monitoring carefully for beneficial and adverse effects.

  11. Organ slices as an in vitro test system for drug metabolism in human liver, lung and kidney

    NARCIS (Netherlands)

    Olinga, Peter; de Jager, M.H; Meijer, D.K F; Groothuis, Geny; Merema, M.T.

    1999-01-01

    Metabolism of xenobiotics occurs mainly in the liver, but in addition, the lungs and kidneys may contribute considerably. The choice of the animal species during drug development as a predictive model for the human condition is often inadequate due to large interspecies differences. Therefore, a

  12. Scaffold-free 3D bio-printed human liver tissue stably maintains metabolic functions useful for drug discovery.

    Science.gov (United States)

    Kizawa, Hideki; Nagao, Eri; Shimamura, Mitsuru; Zhang, Guangyuan; Torii, Hitoshi

    2017-07-01

    The liver plays a central role in metabolism. Although many studies have described in vitro liver models for drug discovery, to date, no model has been described that can stably maintain liver function. Here, we used a unique, scaffold-free 3D bio-printing technology to construct a small portion of liver tissue that could stably maintain drug, glucose, and lipid metabolism, in addition to bile acid secretion. This bio-printed normal human liver tissue maintained expression of several kinds of hepatic drug transporters and metabolic enzymes that functioned for several weeks. The bio-printed liver tissue displayed glucose production via cAMP/protein kinase A signaling, which could be suppressed with insulin. Bile acid secretion was also observed from the printed liver tissue, and it accumulated in the culture medium over time. We observed both bile duct and sinusoid-like structures in the bio-printed liver tissue, which suggested that bile acid secretion occurred via a sinusoid-hepatocyte-bile duct route. These results demonstrated that our bio-printed liver tissue was unique, because it exerted diverse liver metabolic functions for several weeks. In future, we expect our bio-printed liver tissue to be applied to developing new models that can be used to improve preclinical predictions of long-term toxicity in humans, generate novel targets for metabolic liver disease, and evaluate biliary excretion in drug development.

  13. Effects of drugs in subtoxic concentrations on the metabolic fluxes in human hepatoma cell line Hep G2

    International Nuclear Information System (INIS)

    Niklas, Jens; Noor, Fozia; Heinzle, Elmar

    2009-01-01

    Commonly used cytotoxicity assays assess the toxicity of a compound by measuring certain parameters which directly or indirectly correlate to the viability of the cells. However, the effects of a given compound at concentrations considerably below EC 50 values are usually not evaluated. These subtoxic effects are difficult to identify but may eventually cause severe and costly long term problems such as idiosyncratic hepatotoxicity. We determined the toxicity of three hepatotoxic compounds, namely amiodarone, diclofenac and tacrine on the human hepatoma cell line Hep G2 using an online kinetic respiration assay and analysed the effects of subtoxic concentrations of these drugs on the cellular metabolism by using metabolic flux analysis. Several changes in the metabolism could be detected upon exposure to subtoxic concentrations of the test compounds. Upon exposure to diclofenac and tacrine an increase in the TCA-cycle activity was observed which could be a signature of an uncoupling of the oxidative phosphorylation. The results indicate that metabolic flux analysis could serve as an invaluable novel tool for the investigation of the effects of drugs. The described methodology enables tracking the toxicity of compounds dynamically using the respiration assay in a range of concentrations and the metabolic flux analysis permits interesting insights into the changes in the central metabolism of the cell upon exposure to drugs.

  14. Inhibitory effects of drugs on the metabolic activity of mouse and human aldehyde oxidases and influence on drug-drug interactions.

    Science.gov (United States)

    Takaoka, Naoki; Sanoh, Seigo; Okuda, Katsuhiro; Kotake, Yaichiro; Sugahara, Go; Yanagi, Ami; Ishida, Yuji; Tateno, Chise; Tayama, Yoshitaka; Sugihara, Kazumi; Kitamura, Shigeyuki; Kurosaki, Mami; Terao, Mineko; Garattini, Enrico; Ohta, Shigeru

    2018-04-17

    As aldehyde oxidase (AOX) plays an emerging role in drug metabolism, understanding its significance for drug-drug interactions (DDI) is important. Therefore, we tested 10 compounds for species-specific and substrate-dependent differences in the inhibitory effect of AOX activity using genetically engineered HEK293 cells over-expressing human AOX1, mouse AOX1 or mouse AOX3. The IC 50 values of 10 potential inhibitors of the three AOX enzymes were determined using phthalazine and O 6 -benzylguanine as substrates. 17β-Estradiol, menadione, norharmane and raloxifene exhibited marked differences in inhibitory effects between the human and mouse AOX isoforms when the phthalazine substrate was used. Some of the compounds tested exhibited substrate-dependent differences in their inhibitory effects. Docking simulations with human AOX1 and mouse AOX3 were conducted for six representative inhibitors. The rank order of the minimum binding energy reflected the order of the corresponding IC 50 values. We also evaluated the potential DDI between an AOX substrate (O 6 -benzylguanine) and an inhibitor (hydralazine) using chimeric mice with humanized livers. Pretreatment of hydralazine increased the maximum plasma concentration (C max ) and the area under the plasma concentration-time curve (AUC 0-24 ) of O 6 -benzylguanine compared to single administration. Our in vitro data indicate species-specific and substrate-dependent differences in the inhibitory effects on AOX activity. Our in vivo data demonstrate the existence of a DDI which may be of relevance in the clinical context. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Impact of concentration and rate of intraluminal drug delivery on absorption and gut wall metabolism of verapamil in humans.

    Science.gov (United States)

    Glaeser, Hartmut; Drescher, Siegfried; Hofmann, Ute; Heinkele, Georg; Somogyi, Andrew A; Eichelbaum, Michel; Fromm, Martin F

    2004-09-01

    In humans gut wall metabolism can be quantitatively as important as hepatic drug metabolism in limiting the systemic exposure to drugs after oral administration. However, it has been proposed that the role of gut wall metabolism might be overemphasized, because high luminal drug concentrations would lead to a saturation of gut wall metabolism. Therefore we investigated the impact of concentration and rate of intraluminal drug delivery on absorption (F(abs)) and gastrointestinal extraction (E(GI)) of a luminally administered cytochrome P450 (CYP) 3A4 substrate (verapamil) using a multilumen perfusion catheter in combination with a stable isotope technique. Two 20-cm-long, adjacent jejunal segments were isolated with the multilumen perfusion catheter in 7 subjects. In this study 80 mg of unlabeled verapamil (d0-verapamil 15 min) was infused into one segment over a 15-minute period, 80 mg of 3-fold deuterated verapamil (d3-verapamil 240 min) was administered over a 240-minute period into the other segment, and simultaneously, 5 mg of 7-fold deuterated verapamil (d7-verapamil) was injected intravenously over a 15-minute period. The rate of intraluminal drug delivery had only a modest effect on bioavailability of the verapamil isotopes (after correction for F abs ) (F/F abs d3-verapamil 240 min versus d0-verapamil 15 min, 0.24 +/- 0.10 versus 0.20 +/- 0.09; P d3-verapamil 240 min was 0.50 +/- 0.18 compared with 0.59 +/- 0.14 for d0 -verapamil 15 min ( P d0-verapamil 15 min ) correlated strongly with E GI (d3-verapamil 240 min ) (r = 0.94, P d0-verapamil 15 min /d3-verapamil 240 min (r = 0.62, P =.03). Substantial gut wall metabolism of verapamil occurs in humans and can be predicted from ex vivo data by use of shed enterocytes. The different intraluminal concentrations and rates of intraluminal drug delivery did not lead to a pronounced saturation of intestinal drug metabolism.

  16. Pharmacokinetic evaluation of UK-49,858, a metabolically stable triazole antifungal drug, in animals and humans.

    Science.gov (United States)

    Humphrey, M J; Jevons, S; Tarbit, M H

    1985-11-01

    The pharmacokinetic profile of UK-49,858 (fluconazole), a novel triazole antifungal agent which is being developed for oral and intravenous use, was determined in mice, rats, dogs, and humans. Comparative data following oral and intravenous administration showed that bioavailability was essentially complete in all four species. Peak concentrations in plasma of drug normalized to a 1-mg/kg dose level following oral administration, were relatively high: 0.7, 0.6, 1.1, and 1.4 micrograms/ml in mice, rats, dogs, and humans, respectively. The volumes of distribution ranged between 1.1 liter/kg in mice and 0.7 liter/kg in humans, which are approximate to the values for total body water. Whole body autoradiography studies in mice following intravenous administration of [14C]UK-49,858 demonstrated that the drug was evenly distributed throughout the tissues, including the central nervous system and the gastrointestinal tract. Plasma protein binding was low (11 to 12%) in all species. Marked species differences were observed in elimination half-lives, with mean values of 4.8, 4.0, 14, and 22 h in mice, rats, dogs, and humans, respectively. The major route of elimination of the drug was renal clearance, with about 70% of the dose being excreted unchanged in the urine in each species. Studies with [14C]UK-49,858 on metabolism and excretion (intravenous and oral) in mice and dogs showed that about 90% of the dose was recovered as unchanged drug in urine and feces, confirming the metabolic stability of the drug. This pharmacokinetic profile is markedly different from that of imidazole antifungal drugs and undoubtedly contributes to the excellent efficacy of UK-49,858 in vivo.

  17. Effects of atorvastatin metabolites on induction of drug-metabolizing enzymes and membrane transporters through human pregnane X receptor

    Science.gov (United States)

    Hoffart, E; Ghebreghiorghis, L; Nussler, AK; Thasler, WE; Weiss, TS; Schwab, M; Burk, O

    2012-01-01

    BACKGROUND AND PURPOSE Atorvastatin metabolites differ in their potential for drug interaction because of differential inhibition of drug-metabolizing enzymes and transporters. We here investigate whether they exert differential effects on the induction of these genes via activation of pregnane X receptor (PXR) and constitutive androstane receptor (CAR). EXPERIMENTAL APPROACH Ligand binding to PXR or CAR was analysed by mammalian two-hybrid assembly and promoter/reporter gene assays. Additionally, surface plasmon resonance was used to analyse ligand binding to CAR. Primary human hepatocytes were treated with atorvastatin metabolites, and mRNA and protein expression of PXR-regulated genes was measured. Two-hybrid co-activator interaction and co-repressor release assays were utilized to elucidate the molecular mechanism of PXR activation. KEY RESULTS All atorvastatin metabolites induced the assembly of PXR and activated CYP3A4 promoter activity. Ligand binding to CAR could not be proven. In primary human hepatocytes, the para-hydroxy metabolite markedly reduced or abolished induction of cytochrome P450 and transporter genes. While significant differences in co-activator recruitment were not observed, para-hydroxy atorvastatin demonstrated only 50% release of co-repressors. CONCLUSIONS AND IMPLICATIONS Atorvastatin metabolites are ligands of PXR but not of CAR. Atorvastatin metabolites demonstrate differential induction of PXR target genes, which results from impaired release of co-repressors. Consequently, the properties of drug metabolites have to be taken into account when analysing PXR-dependent induction of drug metabolism and transport. The drug interaction potential of the active metabolite, para-hydroxy atorvastatin, might be lower than that of the parent compound. PMID:21913896

  18. Ex vivo preparations of human tissue for drug metabolism, toxicity and transport

    NARCIS (Netherlands)

    Groothuis, Genoveva

    2012-01-01

    Before new drugs are allowed on the market, their safety and metabolite profile should be extensively tested, as often reactive metabolites are the ultimate toxicant. The exposure of the target cell to the drug and its metabolites is determined by the expression levels of the transporters and the

  19. Drug treatment of metabolic syndrome.

    Science.gov (United States)

    Altabas, Velimir

    2013-08-01

    The metabolic syndrome is a constellation of risk factors for cardiovascular diseases including: abdominal obesity, a decreased ability to metabolize glucose (increased blood glucose levels and/or presence of insulin resistance), dyslipidemia, and hypertension. Patients who have developed this syndrome have been shown to be at an increased risk of developing cardiovascular disease and/or type 2 diabetes. Genetic factors and the environment both are important in the development of the metabolic syndrome, influencing all single components of this syndrome. The goals of therapy are to treat the underlying cause of the syndrome, to reduce morbidity, and to prevent complications, including premature death. Lifestyle modification is the preferred first-step treatment of the metabolic syndrome. There is no single effective drug treatment affecting all components of the syndrome equally known yet. However, each component of metabolic syndrome has independent goals to be achieved, so miscellaneous types of drugs are used in the treatment of this syndrome, including weight losing drugs, antidiabetics, antihypertensives, antilipemic and anticlothing drugs etc. This article provides a brief insight into contemporary drug treatment of components the metabolic syndrome.

  20. Long-term exposure to abnormal glucose levels alters drug metabolism pathways and insulin sensitivity in primary human hepatocytes

    Science.gov (United States)

    Davidson, Matthew D.; Ballinger, Kimberly R.; Khetani, Salman R.

    2016-06-01

    Hyperglycemia in type 2 diabetes mellitus has been linked to non-alcoholic fatty liver disease, which can progress to inflammation, fibrosis/cirrhosis, and hepatocellular carcinoma. Understanding how chronic hyperglycemia affects primary human hepatocytes (PHHs) can facilitate the development of therapeutics for these diseases. Conversely, elucidating the effects of hypoglycemia on PHHs may provide insights into how the liver adapts to fasting, adverse diabetes drug reactions, and cancer. In contrast to declining PHH monocultures, micropatterned co-cultures (MPCCs) of PHHs and 3T3-J2 murine embryonic fibroblasts maintain insulin-sensitive glucose metabolism for several weeks. Here, we exposed MPCCs to hypo-, normo- and hyperglycemic culture media for ~3 weeks. While albumin and urea secretion were not affected by glucose level, hypoglycemic MPCCs upregulated CYP3A4 enzyme activity as compared to other glycemic states. In contrast, hyperglycemic MPCCs displayed significant hepatic lipid accumulation in the presence of insulin, while also showing decreased sensitivity to insulin-mediated inhibition of glucose output relative to a normoglycemic control. In conclusion, we show for the first time that PHHs exposed to hypo- and hyperglycemia can remain highly functional, but display increased CYP3A4 activity and selective insulin resistance, respectively. In the future, MPCCs under glycemic states can aid in novel drug discovery and mechanistic investigations.

  1. Toxicokinetics of drugs of abuse: current knowledge of the isoenzymes involved in the human metabolism of tetrahydrocannabinol, cocaine, heroin, morphine, and codeine.

    Science.gov (United States)

    Maurer, Hans H; Sauer, Christoph; Theobald, Denis S

    2006-06-01

    This review summarizes the major metabolic pathways of the drugs of abuse, tetrahydrocannabinol, cocaine, heroin, morphine, and codeine, in humans including the involvement of isoenzymes. This knowledge may be important for predicting their possible interactions with other xenobiotics, understanding pharmaco-/toxicokinetic and pharmacogenetic variations, toxicological risk assessment, developing suitable toxicological analysis procedures, and finally for understanding certain pitfalls in drug testing. The detection times of these drugs and/or their metabolites in biological samples are summarized and the implications of the presented data on the possible interactions of drugs of abuse with other xenobiotics, ie, inhibition or induction of individual polymorphic and nonpolymorphic isoenzymes, discussed.

  2. Toxicity of Xanthene Food Dyes by Inhibition of Human Drug-Metabolizing Enzymes in a Noncompetitive Manner

    International Nuclear Information System (INIS)

    Mizutani, T.

    2010-01-01

    The synthetic food dyes studied were rose bengal (RB), phroxine (PL), amaranth, erythrosine B (ET), allura red, new coccine, acid red (AR), tartrazine, sunset yellow FCF, brilliant blue FCF, and indigo carmine. First, data confirmed that these dyes were not substrates for CYP2A6, UGT1A6, and UGT2B7. ET inhibited UGT1A6 (glucuronidation of p-nitrophenol) and UGT2B7 (glucuronidation of androsterone). We showed the inhibitory effect of xanthene dye on human UGT1A6 activity. Basic ET, PL, and RB in those food dyes strongly inhibited UGT1A6 activity, with IC50 values = 0.05, 0.04, and 0.015 mM, respectively. Meanwhile, AR of an acidic xanthene food dye showed no inhibition. Next, we studied the inhibition of CYP3A4 of a major phase I drug-metabolizing enzyme and P-glycoprotein of a major transporter by synthetic food dyes. Human CYP3A4 and P-glycoprotein were also inhibited by basic xanthene food dyes. The IC50 values of these dyes to inhibit CYP3A4 and P-glycoprotein were the same as the inhibition level of UGT1A6 by three halogenated xanthene food dyes (ET, PL, and RB) described above, except AR, like the results with UGT1A6 and UGT2B7. We also confirmed the non inhibition of CYP3A4 and P-gp by other synthetic food dyes. Part of this inhibition depended upon the reaction of O 12 originating on xanthene dyes by light irradiation, because inhibition was prevented by O 12 quenchers. We studied the influence of superoxide dismutase and catalase on this inhibition by dyes and we found prevention of inhibition by superoxide dismutase but not catalase. This result suggests that superoxide anions, originating on dyes by light irradiation, must attack drug-metabolizing enzymes. It is possible that red cosmetics containing phloxine, erythrosine, or rose bengal react with proteins on skin under lighting and may lead to rough skin.

  3. Toxicity of xanthene food dyes by inhibition of human drug-metabolizing enzymes in a noncompetitive manner.

    Science.gov (United States)

    Mizutani, Takaharu

    2009-01-01

    The synthetic food dyes studied were rose bengal (RB), phroxine (PL), amaranth, erythrosine B (ET), allura red, new coccine, acid red (AR), tartrazine, sunset yellow FCF, brilliant blue FCF, and indigo carmine. First, data confirmed that these dyes were not substrates for CYP2A6, UGT1A6, and UGT2B7. ET inhibited UGT1A6 (glucuronidation of p-nitrophenol) and UGT2B7 (glucuronidation of androsterone). We showed the inhibitory effect of xanthene dye on human UGT1A6 activity. Basic ET, PL, and RB in those food dyes strongly inhibited UGT1A6 activity, with IC(50) values = 0.05, 0.04, and 0.015 mM, respectively. Meanwhile, AR of an acidic xanthene food dye showed no inhibition. Next, we studied the inhibition of CYP3A4 of a major phase I drug-metabolizing enzyme and P-glycoprotein of a major transporter by synthetic food dyes. Human CYP3A4 and P-glycoprotein were also inhibited by basic xanthene food dyes. The IC(50) values of these dyes to inhibit CYP3A4 and P-glycoprotein were the same as the inhibition level of UGT1A6 by three halogenated xanthene food dyes (ET, PL, and RB) described above, except AR, like the results with UGT1A6 and UGT2B7. We also confirmed the noninhibition of CYP3A4 and P-gp by other synthetic food dyes. Part of this inhibition depended upon the reaction of (1)O(2) originating on xanthene dyes by light irradiation, because inhibition was prevented by (1)O(2) quenchers. We studied the influence of superoxide dismutase and catalase on this inhibition by dyes and we found prevention of inhibition by superoxide dismutase but not catalase. This result suggests that superoxide anions, originating on dyes by light irradiation, must attack drug-metabolizing enzymes. It is possible that red cosmetics containing phloxine, erythrosine, or rose bengal react with proteins on skin under lighting and may lead to rough skin.

  4. Toxicity of Xanthene Food Dyes by Inhibition of Human Drug-Metabolizing Enzymes in a Noncompetitive Manner

    Science.gov (United States)

    Mizutani, Takaharu

    2009-01-01

    The synthetic food dyes studied were rose bengal (RB), phroxine (PL), amaranth, erythrosine B (ET), allura red, new coccine, acid red (AR), tartrazine, sunset yellow FCF, brilliant blue FCF, and indigo carmine. First, data confirmed that these dyes were not substrates for CYP2A6, UGT1A6, and UGT2B7. ET inhibited UGT1A6 (glucuronidation of p-nitrophenol) and UGT2B7 (glucuronidation of androsterone). We showed the inhibitory effect of xanthene dye on human UGT1A6 activity. Basic ET, PL, and RB in those food dyes strongly inhibited UGT1A6 activity, with IC50 values = 0.05, 0.04, and 0.015 mM, respectively. Meanwhile, AR of an acidic xanthene food dye showed no inhibition. Next, we studied the inhibition of CYP3A4 of a major phase I drug-metabolizing enzyme and P-glycoprotein of a major transporter by synthetic food dyes. Human CYP3A4 and P-glycoprotein were also inhibited by basic xanthene food dyes. The IC50 values of these dyes to inhibit CYP3A4 and P-glycoprotein were the same as the inhibition level of UGT1A6 by three halogenated xanthene food dyes (ET, PL, and RB) described above, except AR, like the results with UGT1A6 and UGT2B7. We also confirmed the noninhibition of CYP3A4 and P-gp by other synthetic food dyes. Part of this inhibition depended upon the reaction of 1O2 originating on xanthene dyes by light irradiation, because inhibition was prevented by 1O2 quenchers. We studied the influence of superoxide dismutase and catalase on this inhibition by dyes and we found prevention of inhibition by superoxide dismutase but not catalase. This result suggests that superoxide anions, originating on dyes by light irradiation, must attack drug-metabolizing enzymes. It is possible that red cosmetics containing phloxine, erythrosine, or rose bengal react with proteins on skin under lighting and may lead to rough skin. PMID:20041016

  5. Metabolism of designer drugs of abuse.

    Science.gov (United States)

    Staack, Roland F; Maurer, Hans H

    2005-06-01

    Abuse of designer drugs is widespread among young people, especially in the so-called "dance club scene" or "rave scene", worldwide. Severe and even fatal poisonings have been attributed to the consumption of such drugs of abuse. However, in contrast to new medicaments, which are extensively studied in controlled clinical studies concerning metabolism, including cytochrome P450 isoenzyme differentiation, and further pharmacokinetics, designer drugs are consumed without any safety testing. This paper reviews the metabolism of new designer drugs of abuse that have emerged on the black market during the last years. Para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA) and 4-methylthioamphetamine (4-MTA), were taken into consideration as new "classical" amphetamine-derived designer drugs. Furthermore, N-benzylpiperazine (BZP), 1-(3, 4-methylenedioxybenzyl)piperazine (MDBP), 1-(3-trifluoromethylphenyl)piperazine (TFMPP), 1-(3-chlorophenyl)piperazine (mCPP) and 1-(4-methoxyphenyl)piperazine (MeOPP) were taken into consideration as derivatives of the class of piperazine-derived designer drugs, as well as alpha-pyr-rolidinopropiophenone (PPP), 4'-methoxy-alpha-pyrrolidinopropiophenone (MOPPP), 3', 4'-methylenedioxy-alpha-pyrrolidino-propiophenone (MDPPP), 4'-methyl-alpha-pyrrolidinopropiophenone (MPPP), and 4'-methyl-alpha-pyrrolidinoexanophenone (MPHP) as derivatives of the class of alpha-pyrrolidinophenone-derived designer drugs. Papers describing identification of in vivo or in vitro human or animal metabolites and cytochrome P450 isoenzyme dependent metabolism have been considered and summarized.

  6. Human Body Exergy Metabolism

    OpenAIRE

    Mady, Carlos Eduardo Keutenedjian

    2013-01-01

    The exergy analysis of the human body is a tool that can provide indicators of health and life quality. To perform the exergy balance it is necessary to calculate the metabolism on an exergy basis, or metabolic exergy, although there is not yet consensus in its calculation procedure. Hence, the aim of this work is to provide a general method to evaluate this physical quantity for human body based on indirect calorimetry data. To calculate the metabolism on an exergy basis it is necessary to d...

  7. Assessment of chimeric mice with humanized livers in new drug development: generation of pharmacokinetics, metabolism and toxicity data for selecting the final candidate compound.

    Science.gov (United States)

    Kamimura, Hidetaka; Ito, Satoshi

    2016-01-01

    1. Chimeric mice with humanized livers are expected to be a novel tool for new drug development. This review discusses four applications where these animals can be used efficiently to collect supportive data for selecting the best compound in the final stage of drug discovery. 2. The first application is selection of the final compound based on estimated pharmacokinetic parameters in humans. Since chimeric mouse livers are highly repopulated with human hepatocytes, hepatic clearance values in vivo could be used preferentially to estimate pharmacokinetic profiles for humans. 3. The second is prediction of human-specific or disproportionate metabolites. Chimeric mice reproduce human-specific metabolites of drugs under development to conform to ICH guidance M3(R2), except for compounds that were extensively eliminated by co-existing mouse hepatocytes. 4. The third is identifying metabolites with distinct pharmacokinetic profiles in humans. Slow metabolite elimination specifically in humans increases its exposure level, but if its elimination is faster in laboratory animals, the animal exposure level might not satisfy ICH guidance M3(R2). 5. Finally, two examples of reproducing acute liver toxicity in chimeric mice are introduced. Integrated pharmacokinetics, metabolism and toxicity information are expected to assist pharmaceutical scientists in selecting the best candidate compound in new drug development.

  8. Maintenance of drug metabolism and transport functions in human precision-cut liver slices during prolonged incubation for 5 days

    NARCIS (Netherlands)

    Starokozhko, Viktoriia; Vatakuti, Suresh; Schievink, Bauke; Merema, Marjolijn T.; Asplund, Annika; Synnergren, Jane; Aspegren, Anders; Groothuis, Geny M. M.

    Human precision-cut liver slices (hPCLS) are a valuable ex vivo model that can be used in acute toxicity studies. However, a rapid decline in metabolic enzyme activity limits their use in studies that require a prolonged xenobiotic exposure. The aim of the study was to extend the viability and

  9. Advances in drug metabolism and pharmacogenetics research in Australia.

    Science.gov (United States)

    Mackenzie, Peter I; Somogyi, Andrew A; Miners, John O

    2017-02-01

    Metabolism facilitates the elimination, detoxification and excretion in urine or bile (as biotransformation products) of a myriad of structurally diverse drugs and other chemicals. The metabolism of drugs, non-drug xenobiotics and many endogenous compounds is catalyzed by families of drug metabolizing enzymes (DMEs). These include the hemoprotein-containing cytochromes P450, which function predominantly as monooxygenases, and conjugation enzymes that transfer a sugar, sulfate, acetate or glutathione moiety to substrates containing a suitable acceptor functional group. Drug and chemical metabolism, especially the enzymes that catalyse these reactions, has been the research focus of several groups in Australia for over four decades. In this review, we highlight the role of recent and current drug metabolism research in Australia, including elucidation of the structure and function of enzymes from the various DME families, factors that modulate enzyme activity in humans (e.g. drug-drug interactions, gene expression and genetic polymorphism) and the application of in vitro approaches for the prediction of drug metabolism parameters in humans, along with the broader pharmacological/clinical pharmacological and toxicological significance of drug metabolism and DMEs and their relevance to drug discovery and development, and to clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Genetic polymorphisms of drug-metabolizing cytochrome P450 enzymes in cynomolgus and rhesus monkeys and common marmosets in preclinical studies for humans.

    Science.gov (United States)

    Uno, Yasuhiro; Uehara, Shotaro; Yamazaki, Hiroshi

    2017-12-23

    Cynomolgus monkeys (Macaca fascicularis, Old World Monkeys) and common marmosets (Callithrix jacchus, New World Monkeys) have been widely, and expectedly, used as non-human primate models in drug development studies. Major drug-metabolizing cytochrome P450 (P450) enzymes information is now available that supports these primate species as animal models, and it is established that multiple forms of cynomolgus monkey and common marmoset P450 enzymes have generally similar substrate recognition functionality to human P450 enzymes. This research update provides information on genetic polymorphisms of P450 enzymes in cynomolgus monkey and common marmoset like human P450 enzymes. Information on rhesus monkeys (Macaca mulatta), another macaque species used in drug metabolism studies, is also included for comparison. Among a variety of cynomolgus monkey P450 variants investigated, typical examples include individual pharmacokinetic data for efavirenz and R-warfarin associated with cynomolgus monkey P450 2C9 (formerly 2C43) and 2C19 (2C75) variants, respectively, and for R-omeprazole and S-warfarin associated with marmoset P450 2C19 variants. These findings provide a foundation for understanding the individual pharmacokinetic and toxicological results in non-human primates as preclinical models and will help to further support understanding of molecular mechanisms of human P450 function. In addition to these polymorphic P450 enzymes, effects of aging on some drug clearances mediated by cynomolgus monkey and common marmoset P450 enzymes were found in elder animals or animals pretreated with rifampicin. This review describes genetic and acquired individual differences in cynomolgus monkey and common marmoset P450 enzymes involved in drug oxidation associated with pharmacological and/or toxicological effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Relative contributions of the major human CYP450 to the metabolism of icotinib and its implication in prediction of drug-drug interaction between icotinib and CYP3A4 inhibitors/inducers using physiologically based pharmacokinetic modeling.

    Science.gov (United States)

    Chen, Jia; Liu, Dongyang; Zheng, Xin; Zhao, Qian; Jiang, Ji; Hu, Pei

    2015-06-01

    Icotinib is an anticancer drug, but relative contributions of CYP450 have not been identified. This study was carried out to identify the contribution percentage of CYP450 to icotinib and use the results to develop a physiologically based pharmacokinetic (PBPK) model, which can help to predict drug-drug interaction (DDI). Human liver microsome (HLM) and supersome using relative activity factor (RAF) were employed to determine the relative contributions of the major human P450 to the net hepatic metabolism of icotinib. These values were introduced to develop a PBPK model using SimCYP. The model was validated by the observed data in a Phase I clinical trial in Chinese healthy subjects. Finally, the model was used to simulate the DDI with ketoconazole or rifampin. Final contribution of CYP450 isoforms determined by HLM showed that CYP3A4 provided major contributions to the metabolism of icotinib. The percentage contributions of the P450 to the net hepatic metabolism of icotinib were determined by HLM inhibition assay and RAF. The AUC ratio under concomitant use of ketoconazole and rifampin was 3.22 and 0.55, respectively. Percentage of contribution of CYP450 to icotinib metabolism was calculated by RAF. The model has been proven to fit the observed data and is used in predicting icotinib-ketoconazole/rifampin interaction.

  12. Steroid metabolism by monkey and human spermatozoa

    International Nuclear Information System (INIS)

    Rajalakshmi, M.; Sehgal, A.; Pruthi, J.S.; Anand-Kumar, T.C.

    1983-01-01

    Freshly ejaculated spermatozoa from monkey and human were washed and incubated with tritium labelled androgens or estradiol to study the pattern of spermatozoa steroid metabolism. When equal concentrations of steroid substrates were used for incubation, monkey and human spermatozoa showed very similar pattern of steroid conversion. Spermatozoa from both species converted testosterone mainly to androstenedione, but reverse conversion of androstenedione to testosterone was negligible. Estradiol-17 beta was converted mainly to estrone. The close similarity between the spermatozoa of monkey and men in their steroid metabolic pattern indicates that the rhesus monkey could be an useful animal model to study the effect of drugs on the metabolic pattern of human spermatozoa

  13. Human carbonyl reductase 1 participating in intestinal first-pass drug metabolism is inhibited by fatty acids and acyl-CoAs.

    Science.gov (United States)

    Hara, Akira; Endo, Satoshi; Matsunaga, Toshiyuki; El-Kabbani, Ossama; Miura, Takeshi; Nishinaka, Toru; Terada, Tomoyuki

    2017-08-15

    Human carbonyl reductase 1 (CBR1), a member of the short-chain dehydrogenase/reductase (SDR) superfamily, reduces a variety of carbonyl compounds including endogenous isatin, prostaglandin E 2 and 4-oxo-2-nonenal. It is also a major non-cytochrome P450 enzyme in the phase I metabolism of carbonyl-containing drugs, and is highly expressed in the intestine. In this study, we found that long-chain fatty acids and their CoA ester derivatives inhibit CBR1. Among saturated fatty acids, myristic, palmitic and stearic acids were inhibitory, and stearic acid was the most potent (IC 50 9µM). Unsaturated fatty acids (oleic, elaidic, γ-linolenic and docosahexaenoic acids) and acyl-CoAs (palmitoyl-, stearoyl- and oleoyl-CoAs) were more potent inhibitors (IC 50 1.0-2.5µM), and showed high inhibitory selectivity to CBR1 over its isozyme CBR3 and other SDR superfamily enzymes (DCXR and DHRS4) with CBR activity. The inhibition by these fatty acids and acyl-CoAs was competitive with respect to the substrate, showing the K i values of 0.49-1.2µM. Site-directed mutagenesis of the substrate-binding residues of CBR1 suggested that the interactions between the fatty acyl chain and the enzyme's Met141 and Trp229 are important for the inhibitory selectivity. We also examined CBR1 inhibition by oleic acid in cellular levels: The fatty acid effectively inhibited CBR1-mediated 4-oxo-2-nonenal metabolism in colon cancer DLD1 cells and increased sensitivity to doxorubicin in the drug-resistant gastric cancer MKN45 cells that highly express CBR1. The results suggest a possible new food-drug interaction through inhibition of CBR1-mediated intestinal first-pass drug metabolism by dietary fatty acids. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Induction of drug-metabolizing enzymes: mechanisms and consequences

    Energy Technology Data Exchange (ETDEWEB)

    Okey, A.B.; Roberts, E.A.; Harper, P.A.; Denison, M.S.

    1986-04-01

    The activity of many enzymes that carry out biotransformation of drugs and environmental chemicals can be substantially increased by prior exposure of humans or animals to a wide variety of foreign chemicals. Increased enzyme activity is due to true enzyme induction mediated by increased synthesis of mRNAs which code for specific drug-metabolizing enzymes. Several species of cytochrome P-450 are inducible as are certain conjugating enzymes such as glutathione S-transferases, glucuronosyl transferases, and epoxide hydrolases. Induction of drug-metabolizing enzymes has been shown in several instances to alter the efficacy of some therapeutic agents. Induction of various species of cytochrome P-450 also is known to increase the rate at which potentially toxic reactive metabolic intermediates are formed from drugs or environmental chemicals. Overall, however, induction of drug-metabolizing enzymes appears to be a beneficial adaptive response for organisms living in a ''chemically-hostile'' world.48 references.

  15. Two mutant alleles of the human cytochrome P-450dbl gene (P450C2D1) associated with genetically deficient metabolism of debrisoquine and other drugs

    International Nuclear Information System (INIS)

    Skoda, R.C.; Gonzalez, F.L.; Demierre, A.; Meyer, R.A.

    1988-01-01

    The debrisoquine polymorphism is a clinically important genetic defect of drug metabolism affecting 5-10% of individuals in Caucasian populations. It is inherited as an autosomal recessive trait. A full-length cDNA for human cytochrome P-450db1, the deficient enzyme (also designated P450IID1 for P450 family II subfamily D isozyme 1), has recently been cloned. Leukocyte DNA from extensive metabolizers (EMs) or poor metabolizers (PMs) of debrisoquine was examined by Southern analysis. Two polymorphic restriction fragments were associated with the PM phenotype when DNAs from 24 unrelated PM and 29 unrelated EM individuals were probed with P-450db1 cDNA after digestion with Xba I restriction endonuclease and Southern blotting. Seventy-five percent of PMs had either the 44-kb or the 11.5-kb fragment or both. Segregation of these restriction fragment length polymorphisms in the families of six PM probands demonstrated that each of the two fragments is allelic with the 29-kb fragment present in all EM individuals and suggests that they identify two independent mutated alleles of the P-450db1 gene (designated P450C2D1). The Xba I 44-kb fragment and 11.5-kb fragment were in linkage disequilibrium with restriction fragment length polymorphisms generated by four and five additional restriction endonucleases, respectively, which can be used to identify the same mutant alleles for the P-450db1 gene

  16. A mapping of drug space from the viewpoint of small molecule metabolism.

    Directory of Open Access Journals (Sweden)

    James Corey Adams

    2009-08-01

    Full Text Available Small molecule drugs target many core metabolic enzymes in humans and pathogens, often mimicking endogenous ligands. The effects may be therapeutic or toxic, but are frequently unexpected. A large-scale mapping of the intersection between drugs and metabolism is needed to better guide drug discovery. To map the intersection between drugs and metabolism, we have grouped drugs and metabolites by their associated targets and enzymes using ligand-based set signatures created to quantify their degree of similarity in chemical space. The results reveal the chemical space that has been explored for metabolic targets, where successful drugs have been found, and what novel territory remains. To aid other researchers in their drug discovery efforts, we have created an online resource of interactive maps linking drugs to metabolism. These maps predict the "effect space" comprising likely target enzymes for each of the 246 MDDR drug classes in humans. The online resource also provides species-specific interactive drug-metabolism maps for each of the 385 model organisms and pathogens in the BioCyc database collection. Chemical similarity links between drugs and metabolites predict potential toxicity, suggest routes of metabolism, and reveal drug polypharmacology. The metabolic maps enable interactive navigation of the vast biological data on potential metabolic drug targets and the drug chemistry currently available to prosecute those targets. Thus, this work provides a large-scale approach to ligand-based prediction of drug action in small molecule metabolism.

  17. A mapping of drug space from the viewpoint of small molecule metabolism.

    Science.gov (United States)

    Adams, James Corey; Keiser, Michael J; Basuino, Li; Chambers, Henry F; Lee, Deok-Sun; Wiest, Olaf G; Babbitt, Patricia C

    2009-08-01

    Small molecule drugs target many core metabolic enzymes in humans and pathogens, often mimicking endogenous ligands. The effects may be therapeutic or toxic, but are frequently unexpected. A large-scale mapping of the intersection between drugs and metabolism is needed to better guide drug discovery. To map the intersection between drugs and metabolism, we have grouped drugs and metabolites by their associated targets and enzymes using ligand-based set signatures created to quantify their degree of similarity in chemical space. The results reveal the chemical space that has been explored for metabolic targets, where successful drugs have been found, and what novel territory remains. To aid other researchers in their drug discovery efforts, we have created an online resource of interactive maps linking drugs to metabolism. These maps predict the "effect space" comprising likely target enzymes for each of the 246 MDDR drug classes in humans. The online resource also provides species-specific interactive drug-metabolism maps for each of the 385 model organisms and pathogens in the BioCyc database collection. Chemical similarity links between drugs and metabolites predict potential toxicity, suggest routes of metabolism, and reveal drug polypharmacology. The metabolic maps enable interactive navigation of the vast biological data on potential metabolic drug targets and the drug chemistry currently available to prosecute those targets. Thus, this work provides a large-scale approach to ligand-based prediction of drug action in small molecule metabolism.

  18. Studies on the metabolism and toxicological detection of the designer drug 4-methylthioamphetamine (4-MTA) in human urine using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Ewald, Andreas H; Peters, Frank T; Weise, Magdalene; Maurer, Hans H

    2005-09-25

    4-Methylthioamphetamine (4-MTA) is a scheduled designer drug that has appeared on the illicit drug market and led to several non-fatal or even fatal poisonings. Only few data are available on its metabolism. The first aim of this study was to identify the 4-MTA metabolites in human urine and then to study whether the authors' STA procedure is suitable for screening for and identification of 4-MTA and/or its metabolites in urine. After enzymatic cleavage of conjugates, solid-phase extraction (SPE) and acetylation the following metabolites could be identified by full-scan gas chromatography-mass spectrometry (GC-MS): deamino-oxo 4-MTA, deamino-hydroxy 4-MTA, ring hydroxy and beta-hydroxy 4-MTA. 4-MTA sulfoxide could be identified as possible artifact. In urine samples after enzymatic hydrolysis, acidic extraction, and methylation, 4-methylthiobenzoic acid could be identified. The authors' systematical toxicological analysis (STA) procedure using full-scan GC-MS after acid hydrolysis, liquid-liquid extraction (LLE) and acetylation allowed detection of 4-MTA as target analyte plus all the above-mentioned metabolites with the exception of 4-methylthiobenzoic acid. The extraction efficiency of 4-MTA was approximately 70% and the limit of detection (LOD) was 30 ng/ml (S/N 3).

  19. Altered drug metabolism during pregnancy: hormonal regulation of drug-metabolizing enzymes.

    Science.gov (United States)

    Jeong, Hyunyoung

    2010-06-01

    Medication use during pregnancy is prevalent, but pharmacokinetic information of most drugs used during pregnancy is lacking in spite of known effects of pregnancy on drug disposition. Accurate pharmacokinetic information is essential for optimal drug therapy in mother and fetus. Thus, understanding how pregnancy influences drug disposition is important for better prediction of pharmacokinetic changes of drugs in pregnant women. Pregnancy is known to affect hepatic drug metabolism, but the underlying mechanisms remain unknown. Physiological changes accompanying pregnancy are probably responsible for the reported alteration in drug metabolism during pregnancy. These include elevated concentrations of various hormones such as estrogen, progesterone, placental growth hormones and prolactin. This review covers how these hormones influence expression of drug-metabolizing enzymes (DMEs), thus potentially responsible for altered drug metabolism during pregnancy. The reader will gain a greater understanding of the altered drug metabolism in pregnant women and the regulatory effects of pregnancy hormones on expression of DMEs. In-depth studies in hormonal regulatory mechanisms as well as confirmatory studies in pregnant women are warranted for systematic understanding and prediction of the changes in hepatic drug metabolism during pregnancy.

  20. Validation of in vitro cell models used in drug metabolism and transport studies; genotyping of cytochrome P450, phase II enzymes and drug transporter polymorphisms in the human hepatoma (HepG2), ovarian carcinoma (IGROV-1) and colon carcinoma (CaCo-2, LS180) cell lines

    International Nuclear Information System (INIS)

    Brandon, Esther F.A.; Bosch, Tessa M.; Deenen, Maarten J.; Levink, Rianne; Wal, Everdina van der; Meerveld, Joyce B.M. van; Bijl, Monique; Beijnen, Jos H.; Schellens, Jan H.M.; Meijerman, Irma

    2006-01-01

    Human cell lines are often used for in vitro biotransformation and transport studies of drugs. In vivo, genetic polymorphisms have been identified in drug-metabolizing enzymes and ABC-drug transporters leading to altered enzyme activity, or a change in the inducibility of these enzymes. These genetic polymorphisms could also influence the outcome of studies using human cell lines. Therefore, the aim of our study was to pharmacogenotype four cell lines frequently used in drug metabolism and transport studies, HepG2, IGROV-1, CaCo-2 and LS180, for genetic polymorphisms in biotransformation enzymes and drug transporters. The results indicate that, despite the presence of some genetic polymorphisms, no real effects influencing the activity of metabolizing enzymes or drug transporters in the investigated cell lines are expected. However, this characterization will be an aid in the interpretation of the results of biotransformation and transport studies using these in vitro cell models

  1. Metabolism of phthalates in humans

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Skakkebaek, Niels E; Andersson, Anna-Maria

    2007-01-01

    on the foetal testis and they are similar to those seen in humans with testicular dysgenesis syndrome. Therefore, exposure of the human foetus and infants to phthalates via maternal exposure is a matter of concern. The metabolic pathways of phthalate metabolites excreted in human urine are partly known for some...

  2. A Multi-scale Computational Platform to Mechanistically Assess the Effect of Genetic Variation on Drug Responses in Human Erythrocyte Metabolism.

    Science.gov (United States)

    Mih, Nathan; Brunk, Elizabeth; Bordbar, Aarash; Palsson, Bernhard O

    2016-07-01

    Progress in systems medicine brings promise to addressing patient heterogeneity and individualized therapies. Recently, genome-scale models of metabolism have been shown to provide insight into the mechanistic link between drug therapies and systems-level off-target effects while being expanded to explicitly include the three-dimensional structure of proteins. The integration of these molecular-level details, such as the physical, structural, and dynamical properties of proteins, notably expands the computational description of biochemical network-level properties and the possibility of understanding and predicting whole cell phenotypes. In this study, we present a multi-scale modeling framework that describes biological processes which range in scale from atomistic details to an entire metabolic network. Using this approach, we can understand how genetic variation, which impacts the structure and reactivity of a protein, influences both native and drug-induced metabolic states. As a proof-of-concept, we study three enzymes (catechol-O-methyltransferase, glucose-6-phosphate dehydrogenase, and glyceraldehyde-3-phosphate dehydrogenase) and their respective genetic variants which have clinically relevant associations. Using all-atom molecular dynamic simulations enables the sampling of long timescale conformational dynamics of the proteins (and their mutant variants) in complex with their respective native metabolites or drug molecules. We find that changes in a protein's structure due to a mutation influences protein binding affinity to metabolites and/or drug molecules, and inflicts large-scale changes in metabolism.

  3. A Multi-scale Computational Platform to Mechanistically Assess the Effect of Genetic Variation on Drug Responses in Human Erythrocyte Metabolism.

    Directory of Open Access Journals (Sweden)

    Nathan Mih

    2016-07-01

    Full Text Available Progress in systems medicine brings promise to addressing patient heterogeneity and individualized therapies. Recently, genome-scale models of metabolism have been shown to provide insight into the mechanistic link between drug therapies and systems-level off-target effects while being expanded to explicitly include the three-dimensional structure of proteins. The integration of these molecular-level details, such as the physical, structural, and dynamical properties of proteins, notably expands the computational description of biochemical network-level properties and the possibility of understanding and predicting whole cell phenotypes. In this study, we present a multi-scale modeling framework that describes biological processes which range in scale from atomistic details to an entire metabolic network. Using this approach, we can understand how genetic variation, which impacts the structure and reactivity of a protein, influences both native and drug-induced metabolic states. As a proof-of-concept, we study three enzymes (catechol-O-methyltransferase, glucose-6-phosphate dehydrogenase, and glyceraldehyde-3-phosphate dehydrogenase and their respective genetic variants which have clinically relevant associations. Using all-atom molecular dynamic simulations enables the sampling of long timescale conformational dynamics of the proteins (and their mutant variants in complex with their respective native metabolites or drug molecules. We find that changes in a protein's structure due to a mutation influences protein binding affinity to metabolites and/or drug molecules, and inflicts large-scale changes in metabolism.

  4. Antiepileptic drugs and bone metabolism

    Directory of Open Access Journals (Sweden)

    Labban Barbara

    2006-09-01

    Full Text Available Abstract Anti-epileptic medications encompass a wide range of drugs including anticonvulsants, benzodiazepines, enzyme inducers or inhibitors, with a variety effects, including induction of cytochrome P450 and other enzyme, which may lead to catabolism of vitamin D and hypocalcemia and other effects that may significantly effect the risk for low bone mass and fractures. With the current estimates of 50 million people worldwide with epilepsy together with the rapid increase in utilization of these medications for other indications, bone disease associated with the use of anti-epileptic medications is emerging as a serious health threat for millions of people. Nevertheless, it usually goes unrecognized and untreated. In this review we discuss the pathophysiologic mechanisms of bone disease associated with anti-epileptic use, including effect of anti-epileptic agents on bone turnover and fracture risk, highlighting various strategies for prevention of bone loss and associated fractures a rapidly increasing vulnerable population.

  5. 21 CFR 862.3360 - Drug metabolizing enzyme genotyping system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Drug metabolizing enzyme genotyping system. 862... Test Systems § 862.3360 Drug metabolizing enzyme genotyping system. (a) Identification. A drug metabolizing enzyme genotyping system is a device intended for use in testing deoxyribonucleic acid (DNA...

  6. Species differences in drug glucuronidation: Humanized UDP-glucuronosyltransferase 1 mice and their application for predicting drug glucuronidation and drug-induced toxicity in humans.

    Science.gov (United States)

    Fujiwara, Ryoichi; Yoda, Emiko; Tukey, Robert H

    2018-02-01

    More than 20% of clinically used drugs are glucuronidated by a microsomal enzyme UDP-glucuronosyltransferase (UGT). Inhibition or induction of UGT can result in an increase or decrease in blood drug concentration. To avoid drug-drug interactions and adverse drug reactions in individuals, therefore, it is important to understand whether UGTs are involved in metabolism of drugs and drug candidates. While most of glucuronides are inactive metabolites, acyl-glucuronides that are formed from compounds with a carboxylic acid group can be highly toxic. Animals such as mice and rats are widely used to predict drug metabolism and drug-induced toxicity in humans. However, there are marked species differences in the expression and function of drug-metabolizing enzymes including UGTs. To overcome the species differences, mice in which certain drug-metabolizing enzymes are humanized have been recently developed. Humanized UGT1 (hUGT1) mice were created in 2010 by crossing Ugt1-null mice with human UGT1 transgenic mice in a C57BL/6 background. hUGT1 mice can be promising tools to predict human drug glucuronidation and acyl-glucuronide-associated toxicity. In this review article, studies of drug metabolism and toxicity in the hUGT1 mice are summarized. We further discuss research and strategic directions to advance the understanding of drug glucuronidation in humans. Copyright © 2017 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  7. Preclinical experimental models of drug metabolism and disposition in drug discovery and development

    Directory of Open Access Journals (Sweden)

    Donglu Zhang

    2012-12-01

    Full Text Available Drug discovery and development involve the utilization of in vitro and in vivo experimental models. Different models, ranging from test tube experiments to cell cultures, animals, healthy human subjects, and even small numbers of patients that are involved in clinical trials, are used at different stages of drug discovery and development for determination of efficacy and safety. The proper selection and applications of correct models, as well as appropriate data interpretation, are critically important in decision making and successful advancement of drug candidates. In this review, we discuss strategies in the applications of both in vitro and in vivo experimental models of drug metabolism and disposition.

  8. Glycogen metabolism in humans

    OpenAIRE

    Adeva-Andany, María M.; González-Lucán, Manuel; Donapetry-García, Cristóbal; Fernández-Fernández, Carlos; Ameneiros-Rodríguez, Eva

    2016-01-01

    In the human body, glycogen is a branched polymer of glucose stored mainly in the liver and the skeletal muscle that supplies glucose to the blood stream during fasting periods and to the muscle cells during muscle contraction. Glycogen has been identified in other tissues such as brain, heart, kidney, adipose tissue, and erythrocytes, but glycogen function in these tissues is mostly unknown. Glycogen synthesis requires a series of reactions that include glucose entrance into the cell through...

  9. Metabolism of phthalates in humans

    DEFF Research Database (Denmark)

    Frederiksen, Hanne; Skakkebaek, Niels E; Andersson, Anna-Maria

    2007-01-01

    on the foetal testis and they are similar to those seen in humans with testicular dysgenesis syndrome. Therefore, exposure of the human foetus and infants to phthalates via maternal exposure is a matter of concern. The metabolic pathways of phthalate metabolites excreted in human urine are partly known for some...... phthalates, but our knowledge about metabolic distribution in the body and other biological fluids, including breast milk, is limited. Compared to urine, human breast milk contains relatively more of the hydrophobic phthalates, such as di-n-butyl phthalate and the longer-branched, di(2-ethylhexyl) phthalate...... (DEHP) and di-iso-nonyl phthalate (DiNP); and their monoester metabolites. Urine, however, contains relatively more of the secondary metabolites of DEHP and DiNP, as well as the monoester phthalates of the more short-branched phthalates. This differential distribution is of special concern as...

  10. Uses and limits of radiotracers in the study of drugs and xenobiotics metabolism

    International Nuclear Information System (INIS)

    Cohen, Y.

    1980-01-01

    This review deals with scientific papers issued in 1977-1978, on labelling of drugs and xenobiotics and their metabolism. It is divided in five parts: site of label; in vivo metabolism in animals and human beings; in vitro metabolism on tissue slices, cells culture, microsomes, membrane receptors; metabolism of xenobiotics: nutrients, food additives, detergents, plastics and fabrics; discussion. Metabolic studies, nowadays, associate radiotracers, stable isotopes with high performing procedures for analytical separation [fr

  11. Human metabolism of caesium

    International Nuclear Information System (INIS)

    Raeaef, C.L.; Falk, R.; Lauridsen, Bente; Rahola, T.; Soogard-Hansen, J.

    2006-04-01

    A study of the human biokinetics of caesium in two forms, i.) incorporated in foodstuff (137Cs in perch and mushrooms) and ii.) in ionic state ( 134 Cs in aqueous solution) has been carried out at the department of Radiation Physics in Malmoe, starting in 2001. The results of the pilot study were published in 2004, and a continuation of that study has now been carried out by means of NKS funding (NKS-B Cskinetik). The aim is to, i.) investigate whether Scandinavian populations exhibit shorter biological half-time of radiocaesium than other populations; ii.) extend the biokinetic study to additional human subjects from the other Nordic countries. Results from the continued study further indicate a near complete absorption of radiocaesium in the gastro-intestinal tract, be it in ion state or contained in food matrix. So far, the literature survey of Nordic studies on biokinetics of Cs suggests that the biological half time is somewhat shorter among Scandinavian males (84 days vs. ICRP-value of 110 days), although females do not exhibit any significant difference (64 days vs ICRP value of 65 days). (au)

  12. Human metabolism of caesium

    Energy Technology Data Exchange (ETDEWEB)

    Raeaef, C.L. [Lund Univ., Dept. of Radiation Physics in Malmoe (Sweden); Falk, R. [Swedish Radiation Protection Authority (Sweden); Lauridsen, Bente [Risoe National Lab. (Denmark); Rahola, T. [STUK - Radiation and Nuclear Safety Authority (Finland); Soogard-Hansen, J. [NRPA - Norwegian Radiation Protection Authority (Norway)

    2006-04-15

    A study of the human biokinetics of caesium in two forms, i.) incorporated in foodstuff (137Cs in perch and mushrooms) and ii.) in ionic state ({sup 134}Cs in aqueous solution) has been carried out at the department of Radiation Physics in Malmoe, starting in 2001. The results of the pilot study were published in 2004, and a continuation of that study has now been carried out by means of NKS funding (NKS-B Cskinetik). The aim is to, i.) investigate whether Scandinavian populations exhibit shorter biological half-time of radiocaesium than other populations; ii.) extend the biokinetic study to additional human subjects from the other Nordic countries. Results from the continued study further indicate a near complete absorption of radiocaesium in the gastro-intestinal tract, be it in ion state or contained in food matrix. So far, the literature survey of Nordic studies on biokinetics of Cs suggests that the biological half time is somewhat shorter among Scandinavian males (84 days vs. ICRP-value of 110 days), although females do not exhibit any significant difference (64 days vs ICRP value of 65 days). (au)

  13. Pharmacogenomic and clinical data link non-pharmacokinetic metabolic dysregulation to drug side effect pathogenesis

    DEFF Research Database (Denmark)

    Zielinski, Daniel C.; Filipp, F. V.; Bordbar, A.

    2015-01-01

    Drug side effects cause a significant clinical and economic burden. However, mechanisms of drug action underlying side effect pathogenesis remain largely unknown. Here, we integrate pharmacogenomic and clinical data with a human metabolic network and find that non-pharmacokinetic metabolic pathways...

  14. Drug discovery strategies in the field of tumor energy metabolism: Limitations by metabolic flexibility and metabolic resistance to chemotherapy.

    Science.gov (United States)

    Amoedo, N D; Obre, E; Rossignol, R

    2017-08-01

    The search for new drugs capable of blocking the metabolic vulnerabilities of human tumors has now entered the clinical evaluation stage, but several projects already failed in phase I or phase II. In particular, very promising in vitro studies could not be translated in vivo at preclinical stage and beyond. This was the case for most glycolysis inhibitors that demonstrated systemic toxicity. A more recent example is the inhibition of glutamine catabolism in lung adenocarcinoma that failed in vivo despite a strong addiction of several cancer cell lines to glutamine in vitro. Such contradictory findings raised several questions concerning the optimization of drug discovery strategies in the field of cancer metabolism. For instance, the cell culture models in 2D or 3D might already show strong limitations to mimic the tumor micro- and macro-environment. The microenvironment of tumors is composed of cancer cells of variegated metabolic profiles, supporting local metabolic exchanges and symbiosis, but also of immune cells and stroma that further interact with and reshape cancer cell metabolism. The macroenvironment includes the different tissues of the organism, capable of exchanging signals and fueling the tumor 'a distance'. Moreover, most metabolic targets were identified from their increased expression in tumor transcriptomic studies, or from targeted analyses looking at the metabolic impact of particular oncogenes or tumor suppressors on selected metabolic pathways. Still, very few targets were identified from in vivo analyses of tumor metabolism in patients because such studies are difficult and adequate imaging methods are only currently being developed for that purpose. For instance, perfusion of patients with [ 13 C]-glucose allows deciphering the metabolomics of tumors and opens a new area in the search for effective targets. Metabolic imaging with positron emission tomography and other techniques that do not involve [ 13 C] can also be used to evaluate tumor

  15. Interplay of Drug-Metabolizing Enzymes and Transporters in Drug Absorption and Disposition.

    Science.gov (United States)

    Shi, Shaojun; Li, Yunqiao

    2014-01-01

    In recent years, the functional interplay between drug-metabolizing enzymes (DMEs) and drug transporters (DTs) in drug absorption and disposition, as well as the complex drug interactions (DIs), has become an intriguing contention, which has also been termed the "transport-metabolism interplay". The current mechanistic understanding for this interplay is first discussed. In the present article, studies investigating the interplay between cytochrome P450 enzymes (CYPs) and efflux transporters have been systematically reviewed in vitro, in situ, in silico, in animals and humans, followed by CYPs-uptake transporters, CYPs-uptake transporters-efflux transporters, and phase II metabolic enzymes-transporters interplay studies. Although several cellular, isolated organ and whole animal studies, in conjunction with simulation and modelling, have addressed the issue that DMEs and DTs can work cooperatively to affect the bioavailability of shared substrate drugs, convincing evidences in human studies are still lacking. Furthermore, the functional interplay between DMEs and DTs will be highly substrate- and dose- dependent. Additionally, we review recent studies to evaluate the influence of genetic variations in the interplay between DMEs and DTs, which might be helpful for the prediction of pharmacokinetics (PK) and possible DIs in human more correctly. There is strong evidence of coordinately regulated DEMs and DTs gene expression and protein activity (e.g. nuclear receptors). Taken together, further investigations and analysis are urgently needed to explore the functional interplay of DMEs and DTs and to delineate the underlying mechanisms.

  16. Bile Acid Signaling in Metabolic Disease and Drug Therapy

    Science.gov (United States)

    Li, Tiangang

    2014-01-01

    Bile acids are the end products of cholesterol catabolism. Hepatic bile acid synthesis accounts for a major fraction of daily cholesterol turnover in humans. Biliary secretion of bile acids generates bile flow and facilitates hepatobiliary secretion of lipids, lipophilic metabolites, and xenobiotics. In the intestine, bile acids are essential for the absorption, transport, and metabolism of dietary fats and lipid-soluble vitamins. Extensive research in the last 2 decades has unveiled new functions of bile acids as signaling molecules and metabolic integrators. The bile acid–activated nuclear receptors farnesoid X receptor, pregnane X receptor, constitutive androstane receptor, vitamin D receptor, and G protein–coupled bile acid receptor play critical roles in the regulation of lipid, glucose, and energy metabolism, inflammation, and drug metabolism and detoxification. Bile acid synthesis exhibits a strong diurnal rhythm, which is entrained by fasting and refeeding as well as nutrient status and plays an important role for maintaining metabolic homeostasis. Recent research revealed an interaction of liver bile acids and gut microbiota in the regulation of liver metabolism. Circadian disturbance and altered gut microbiota contribute to the pathogenesis of liver diseases, inflammatory bowel diseases, nonalcoholic fatty liver disease, diabetes, and obesity. Bile acids and their derivatives are potential therapeutic agents for treating metabolic diseases of the liver. PMID:25073467

  17. Metabolic and redox barriers in the skin exposed to drugs and xenobiotics.

    Science.gov (United States)

    Korkina, Liudmila

    2016-01-01

    Growing exposure of human skin to environmental and occupational hazards, to numerous skin care/beauty products, and to topical drugs led to a biomedical concern regarding sustainability of cutaneous chemical defence that is essential for protection against intoxication. Since skin is the largest extra-hepatic drug/xenobiotic metabolising organ where redox-dependent metabolic pathways prevail, in this review, publications on metabolic processes leading to redox imbalance (oxidative stress) and its autocrine/endocrine impact to cutaneous drug/xenobiotic metabolism were scrutinised. Chemical and photo-chemical skin barriers contain metabolic and redox compartments: their protective and homeostatic functions. The review will examine the striking similarity of adaptive responses to exogenous chemical/photo-chemical stressors and endogenous toxins in cutaneous metabolic and redox system; the role(s) of xenobiotics/drugs and phase II enzymes in the endogenous antioxidant defence and maintenance of redox balance; redox regulation of interactions between metabolic and inflammatory responses in skin cells; skin diseases sharing metabolic and redox problems (contact dermatitis, lupus erythematosus, and vitiligo) Due to exceptional the redox dependence of cutaneous metabolic pathways and interaction of redox active metabolites/exogenous antioxidants with drug/xenobiotic metabolism, metabolic tests of topical xenobiotics/drugs should be combined with appropriate redox analyses and performed on 3D human skin models.

  18. The effect of non-steroidal anti-inflammatory drugs on the metabolism of /sup 14/C-arachidonic acid by human gingival tissue in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Elattar, T.M.; Lin, H.S.; Tira, D.E.

    1983-09-01

    We investigated the effect of non-steroidal anti-inflammatory drugs on prostaglandins (PGs) and 12-hydroxyeicosatetraenoic acid (12-HETE) formation by inflamed human gingival tissues. Gingival tissue homogenates were incubated with /sup 14/C-arachidonic acid in the presence of indomethacin, piroxicam, or ibuprofen, and the organic solvent extracts were chromatographed on silica gel plates with standards for radiometric assay. There was a significant negative trend between the doses (10(-7)-10(-3) M) of each of indomethacin, piroxicam, and ibuprofen, and the amounts of PGF2 alpha, PGE2, PGD2, and 15-keto-PGE2 produced. All three drugs have a significant inhibitory effect on PGs and 12-HETE production at 10(-3) M when compared with the control. The rank order effectiveness of the drugs, at 10(-3) M, on PG inhibition was indomethacin greater than piroxicam greater than ibuprofen, and on 12-HETE inhibition was indomethacin greater than ibuprofen greater than piroxicam.

  19. The effect of non-steroidal anti-inflammatory drugs on the metabolism of 14C-arachidonic acid by human gingival tissue in vitro

    International Nuclear Information System (INIS)

    Elattar, T.M.; Lin, H.S.; Tira, D.E.

    1983-01-01

    We investigated the effect of non-steroidal anti-inflammatory drugs on prostaglandins (PGs) and 12-hydroxyeicosatetraenoic acid (12-HETE) formation by inflamed human gingival tissues. Gingival tissue homogenates were incubated with 14 C-arachidonic acid in the presence of indomethacin, piroxicam, or ibuprofen, and the organic solvent extracts were chromatographed on silica gel plates with standards for radiometric assay. There was a significant negative trend between the doses (10(-7)-10(-3) M) of each of indomethacin, piroxicam, and ibuprofen, and the amounts of PGF2 alpha, PGE2, PGD2, and 15-keto-PGE2 produced. All three drugs have a significant inhibitory effect on PGs and 12-HETE production at 10(-3) M when compared with the control. The rank order effectiveness of the drugs, at 10(-3) M, on PG inhibition was indomethacin greater than piroxicam greater than ibuprofen, and on 12-HETE inhibition was indomethacin greater than ibuprofen greater than piroxicam

  20. Interplay of drug metabolizing enzymes with cellular transporters.

    Science.gov (United States)

    Böhmdorfer, Michaela; Maier-Salamon, Alexandra; Riha, Juliane; Brenner, Stefan; Höferl, Martina; Jäger, Walter

    2014-11-01

    Many endogenous and xenobiotic substances and their metabolites are substrates for drug metabolizing enzymes and cellular transporters. These proteins may not only contribute to bioavailability of molecules but also to uptake into organs and, consequently, to overall elimination. The coordinated action of uptake transporters, metabolizing enzymes, and efflux pumps, therefore, is a precondition for detoxification and elimination of drugs. As the understanding of the underlying mechanisms is important to predict alterations in drug disposal, adverse drug reactions and, finally, drug-drug interactions, this review illustrates the interplay between selected uptake/efflux transporters and phase I/II metabolizing enzymes.

  1. Associations of Drug Lipophilicity and Extent of Metabolism with Drug-Induced Liver Injury.

    Science.gov (United States)

    McEuen, Kristin; Borlak, Jürgen; Tong, Weida; Chen, Minjun

    2017-06-22

    Drug-induced liver injury (DILI), although rare, is a frequent cause of adverse drug reactions resulting in warnings and withdrawals of numerous medications. Despite the research community's best efforts, current testing strategies aimed at identifying hepatotoxic drugs prior to human trials are not sufficiently powered to predict the complex mechanisms leading to DILI. In our previous studies, we demonstrated lipophilicity and dose to be associated with increased DILI risk and, and in our latest work, we factored reactive metabolites into the algorithm to predict DILI. Given the inconsistency in determining the potential for drugs to cause DILI, the present study comprehensively assesses the relationship between DILI risk and lipophilicity and the extent of metabolism using a large published dataset of 1036 Food and Drug Administration (FDA)-approved drugs by considering five independent DILI annotations. We found that lipophilicity and the extent of metabolism alone were associated with increased risk for DILI. Moreover, when analyzed in combination with high daily dose (≥100 mg), lipophilicity was statistically significantly associated with the risk of DILI across all datasets ( p < 0.05). Similarly, the combination of extensive hepatic metabolism (≥50%) and high daily dose (≥100 mg) was also strongly associated with an increased risk of DILI among all datasets analyzed ( p < 0.05). Our results suggest that both lipophilicity and the extent of hepatic metabolism can be considered important risk factors for DILI in humans, and that this relationship to DILI risk is much stronger when considered in combination with dose. The proposed paradigm allows the convergence of different published annotations to a more uniform assessment.

  2. Nutritional conditioning : The effect of fasting on drug metabolism

    NARCIS (Netherlands)

    Lammers, L.A.

    2018-01-01

    The studies described in this thesis focus on the effect of fasting, as nutritional modulator, on drug metabolism. Drug metabolism varies considerably between and within patients, which may result in treatment failure or, conversely, in untoward side effects. Many factors contribute to the

  3. Pharmacological interventions in human HDL metabolism

    NARCIS (Netherlands)

    Balder, Jan-Willem; Staels, Bart; Kuivenhoven, Jan A.

    2013-01-01

    PURPOSE OF REVIEW: This review focuses on the recent developments in the field of drugs that affect HDL metabolism. Additionally, some general (retrospective) thoughts on fighting cardiovascular disease through modulating circulating lipids are discussed. RECENT FINDINGS: Recently, the large

  4. NMR spectroscopy applied to the eye: Drugs and metabolic studies

    Energy Technology Data Exchange (ETDEWEB)

    Saether, Oddbjoern

    2005-07-01

    NMR spectroscopy has been extensively applied in biomedical research during the last decades. It has proved to be an analytical tool of great value. From being mainly used in chemistry, technological developments have expanded the application of NMR spectroscopy to a great wealth of disciplines. With this method, biochemical information can be obtained by analysing tissue extracts. Moreover, NMR spectroscopy is increasingly employed for pharmacokinetic studies and analysis of biofluids. Technological progress has provided increased sensitivity and resolution in the spectra, which enable even more of the complexity of biological samples to be elucidated. With the implementation of high-resolution magic angle spinning (HR-MAS) NMR spectroscopy in biomedicine, intact tissue samples or biopsies can be investigated. Thus, NMR spectroscopy has an ever-increasing impact in metabolic screening of human samples and in animal models, and methods are also increasingly realised in vivo. The present work, NMR spectroscopy applied to eye research, consists of two main parts. Firstly, the feasibility to monitor fluorinated ophthalmic drugs directly in the eye was assessed. Secondly, HR-MAS H1 NMR spectroscopy was applied for metabolic profiling of the anterior eye segment, specifically to analyse metabolic changes in intact corneal and lenticular samples after cataractogenic insults. This work included metabonomics with the application of pattern recognition methods to analyse HR-MAS spectra of eye tissues. Optimisation strategies were explored for F19 NMR detection of fluorinated drugs in a phantom eye. S/N gains in F19 NMR spectroscopy were achieved by implementing time-share H1 decoupling at 2.35 T. The method is advantageous for compounds displaying broad spectral coupling patterns, though detection of drugs at concentrations encountered in the anterior eye segment after topical application was not feasible. Higher magnetic fields and technological improvements could enable

  5. NMR spectroscopy applied to the eye: Drugs and metabolic studies

    International Nuclear Information System (INIS)

    Saether, Oddbjoern

    2005-01-01

    NMR spectroscopy has been extensively applied in biomedical research during the last decades. It has proved to be an analytical tool of great value. From being mainly used in chemistry, technological developments have expanded the application of NMR spectroscopy to a great wealth of disciplines. With this method, biochemical information can be obtained by analysing tissue extracts. Moreover, NMR spectroscopy is increasingly employed for pharmacokinetic studies and analysis of biofluids. Technological progress has provided increased sensitivity and resolution in the spectra, which enable even more of the complexity of biological samples to be elucidated. With the implementation of high-resolution magic angle spinning (HR-MAS) NMR spectroscopy in biomedicine, intact tissue samples or biopsies can be investigated. Thus, NMR spectroscopy has an ever-increasing impact in metabolic screening of human samples and in animal models, and methods are also increasingly realised in vivo. The present work, NMR spectroscopy applied to eye research, consists of two main parts. Firstly, the feasibility to monitor fluorinated ophthalmic drugs directly in the eye was assessed. Secondly, HR-MAS H1 NMR spectroscopy was applied for metabolic profiling of the anterior eye segment, specifically to analyse metabolic changes in intact corneal and lenticular samples after cataractogenic insults. This work included metabonomics with the application of pattern recognition methods to analyse HR-MAS spectra of eye tissues. Optimisation strategies were explored for F19 NMR detection of fluorinated drugs in a phantom eye. S/N gains in F19 NMR spectroscopy were achieved by implementing time-share H1 decoupling at 2.35 T. The method is advantageous for compounds displaying broad spectral coupling patterns, though detection of drugs at concentrations encountered in the anterior eye segment after topical application was not feasible. Higher magnetic fields and technological improvements could enable

  6. Understanding specificity in metabolic pathways-Structural biology of human nucleotide metabolism

    International Nuclear Information System (INIS)

    Welin, Martin; Nordlund, Paer

    2010-01-01

    Interactions are the foundation of life at the molecular level. In the plethora of activities in the cell, the evolution of enzyme specificity requires the balancing of appropriate substrate affinity with a negative selection, in order to minimize interactions with other potential substrates in the cell. To understand the structural basis for enzyme specificity, the comparison of structural and biochemical data between enzymes within pathways using similar substrates and effectors is valuable. Nucleotide metabolism is one of the largest metabolic pathways in the human cell and is of outstanding therapeutic importance since it activates and catabolises nucleoside based anti-proliferative drugs and serves as a direct target for anti-proliferative drugs. In recent years the structural coverage of the enzymes involved in human nucleotide metabolism has been dramatically improved and is approaching completion. An important factor has been the contribution from the Structural Genomics Consortium (SGC) at Karolinska Institutet, which recently has solved 33 novel structures of enzymes and enzyme domains in human nucleotide metabolism pathways and homologs thereof. In this review we will discuss some of the principles for substrate specificity of enzymes in human nucleotide metabolism illustrated by a selected set of enzyme families where a detailed understanding of the structural determinants for specificity is now emerging.

  7. Current status of prediction of drug disposition and toxicity in humans using chimeric mice with humanized liver.

    Science.gov (United States)

    Kitamura, Shigeyuki; Sugihara, Kazumi

    2014-01-01

    1. Human-chimeric mice with humanized liver have been constructed by transplantation of human hepatocytes into several types of mice having genetic modifications that injure endogenous liver cells. Here, we focus on liver urokinase-type plasminogen activator-transgenic severe combined immunodeficiency (uPA/SCID) mice, which are the most widely used human-chimeric mice. Studies so far indicate that drug metabolism, drug transport, pharmacological effects and toxicological action in these mice are broadly similar to those in humans. 2. Expression of various drug-metabolizing enzymes is known to be different between humans and rodents. However, the expression pattern of cytochrome P450, aldehyde oxidase and phase II enzymes in the liver of human-chimeric mice resembles that in humans, not that in the host mice. 3. Metabolism of various drugs, including S-warfarin, zaleplon, ibuprofen, naproxen, coumarin, troglitazone and midazolam, in human-chimeric mice is mediated by human drug-metabolizing enzymes, not by host mouse enzymes, and thus resembles that in humans. 4. Pharmacological and toxicological effects of various drugs in human-chimeric mice are also similar to those in humans. 5. The current consensus is that chimeric mice with humanized liver are useful to predict drug metabolism catalyzed by cytochrome P450, aldehyde oxidase and phase II enzymes in humans in vivo and in vitro. Some remaining issues are discussed in this review.

  8. The effect of the antipsoriatic drug metabolite etretin (Ro 10-1670) on UVB irradiation induced changes in the metabolism of arachidonic acid in human keratinocytes in culture

    International Nuclear Information System (INIS)

    Punnonen, Kari; Jansen, C.T.; Puustinen, Tapio

    1986-01-01

    [ 14 C]Arachidonic acid was avidly incorporated into human keratinocytes in culture and following exposure to UVB irradiation of 9 mJ/cm 2 (erythemally effective, EE) substantial amounts of 14 C-radiolabel were released from the cells. The release of radiolabel was accompanied by a decrease in the labelling of phosphatidylethanolamine whereas the labelling of triacylglycerols and cholesteryl esters was increased. Keratinocytes produced significant amounts of prostaglandin E 2 (PGE 2 ) and following UVB irradiation of 9 mJ/cm 2 (EE) the formation of prostaglandin E 2 was increased. Etretin (Ro 10-1670), the active metabolite of the antipsoriatic drug etretinate (Ro 10-9359), affected significantly neither the total release of radiolabel induced by UVB nor the formation of prostaglandin E 2 . However, in the presence of etretin the UVB irradiation induced transfer of [ 14 C]arachidonic acid into triacylglycerols and cholesteryl esters was not increased as much as in the corresponding experiments without etretin. On the basis of the present study it appears that etretin dose not interfere with the release of arachidonic acid in amounts which could be related to the therapeutic effects of the combination of retinoids with UVB irradiation (Re-UVB) in the treatment of psoriasis. (author)

  9. Significance and challenges of stereoselectivity assessing methods in drug metabolism

    Directory of Open Access Journals (Sweden)

    Zhuowei Shen

    2016-02-01

    Full Text Available Stereoselectivity in drug metabolism can not only influence the pharmacological activities, tolerability, safety, and bioavailability of drugs directly, but also cause different kinds of drug–drug interactions. Thus, assessing stereoselectivity in drug metabolism is of great significance for pharmaceutical research and development (R&D and rational use in clinic. Although there are various methods available for assessing stereoselectivity in drug metabolism, many of them have shortcomings. The indirect method of chromatographic methods can only be applicable to specific samples with functional groups to be derivatized or form complex with a chiral selector, while the direct method achieved by chiral stationary phases (CSPs is expensive. As a detector of chromatographic methods, mass spectrometry (MS is highly sensitive and specific, whereas the matrix interference is still a challenge to overcome. In addition, the use of nuclear magnetic resonance (NMR and immunoassay in chiral analysis are worth noting. This review presents several typical examples of drug stereoselective metabolism and provides a literature-based evaluation on current chiral analytical techniques to show the significance and challenges of stereoselectivity assessing methods in drug metabolism.

  10. Intrinsic and Antipsychotic Drug-Induced Metabolic Dysfunction in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Zachary Freyberg

    2017-07-01

    Full Text Available For decades, there have been observations demonstrating significant metabolic disturbances in people with schizophrenia including clinically relevant weight gain, hypertension, and disturbances in glucose and lipid homeostasis. Many of these findings pre-date the use of antipsychotic drugs (APDs which on their own are also strongly associated with metabolic side effects. The combination of APD-induced metabolic changes and common adverse environmental factors associated with schizophrenia have made it difficult to determine the specific contributions of each to the overall metabolic picture. Data from drug-naïve patients, both from the pre-APD era and more recently, suggest that there may be an intrinsic metabolic risk associated with schizophrenia. Nevertheless, these findings remain controversial due to significant clinical variability in both psychiatric and metabolic symptoms throughout patients' disease courses. Here, we provide an extensive review of classic and more recent literature describing the metabolic phenotype associated with schizophrenia. We also suggest potential mechanistic links between signaling pathways associated with schizophrenia and metabolic dysfunction. We propose that, beyond its symptomatology in the central nervous system, schizophrenia is also characterized by pathophysiology in other organ systems directly related to metabolic control.

  11. Bioanalysis, metabolism & clinical pharmacology of antiretroviral drugs

    NARCIS (Netherlands)

    Heine, R. ter

    2009-01-01

    The aims of all studies described in this thesis were to develop new bioanalytical and more patient friendly methods for studying the clinical pharmacology of antiretroviral drugs and to ultimately improve antiretroviral treatment.

  12. Genetic alterations affecting cholesterol metabolism and human fertility.

    Science.gov (United States)

    DeAngelis, Anthony M; Roy-O'Reilly, Meaghan; Rodriguez, Annabelle

    2014-11-01

    Single nucleotide polymorphisms (SNPs) represent genetic variations among individuals in a population. In medicine, these small variations in the DNA sequence may significantly impact an individual's response to certain drugs or influence the risk of developing certain diseases. In the field of reproductive medicine, a significant amount of research has been devoted to identifying polymorphisms which may impact steroidogenesis and fertility. This review discusses current understanding of the effects of genetic variations in cholesterol metabolic pathways on human fertility that bridge novel linkages between cholesterol metabolism and reproductive health. For example, the role of the low-density lipoprotein receptor (LDLR) in cellular metabolism and human reproduction has been well studied, whereas there is now an emerging body of research on the role of the high-density lipoprotein (HDL) receptor scavenger receptor class B type I (SR-BI) in human lipid metabolism and female reproduction. Identifying and understanding how polymorphisms in the SCARB1 gene or other genes related to lipid metabolism impact human physiology is essential and will play a major role in the development of personalized medicine for improved diagnosis and treatment of infertility. © 2014 by the Society for the Study of Reproduction, Inc.

  13. Acute Metabolic Changes Associated With Analgesic Drugs

    DEFF Research Database (Denmark)

    Hansen, Tine Maria; Olesen, Anne Estrup; Simonsen, Carsten Wiberg

    2016-01-01

    BACKGROUND AND PURPOSE: Magnetic resonance spectroscopy (MRS) is used to measure brain metabolites. Limited data exist on the analgesic-induced spectroscopy response. This was an explorative study with the aims to investigate the central effects of two analgesic drugs, an opioid and a selective...

  14. Antilipolytic drug boosts glucose metabolism in prostate cancer

    DEFF Research Database (Denmark)

    Andersen, Kim Francis; Divilov, Vadim; Koziorowski, Jacek

    2013-01-01

    The antilipolytic drug Acipimox reduces free fatty acid (FFA) levels in the blood stream. We examined the effect of reduced FFAs on glucose metabolism in androgen-dependent (CWR22Rv1) and androgen-independent (PC3) prostate cancer (PCa) xenografts.......The antilipolytic drug Acipimox reduces free fatty acid (FFA) levels in the blood stream. We examined the effect of reduced FFAs on glucose metabolism in androgen-dependent (CWR22Rv1) and androgen-independent (PC3) prostate cancer (PCa) xenografts....

  15. Fast prediction of cytochrome P450 mediated drug metabolism

    DEFF Research Database (Denmark)

    Rydberg, Patrik Åke Anders; Poongavanam, Vasanthanathan; Oostenbrink, Chris

    2009-01-01

    Cytochrome P450 mediated metabolism of drugs is one of the major determinants of their kinetic profile, and prediction of this metabolism is therefore highly relevant during the drug discovery and development process. A new rule-based method, based on results from density functional theory...... calculations, for predicting activation energies for aliphatic and aromatic oxidations by cytochromes P450 is developed and compared with several other methods. Although the applicability of the method is currently limited to a subset of P450 reactions, these reactions describe more than 90...

  16. Dabigatran - Metabolism, Pharmacologic Properties and Drug Interactions.

    Science.gov (United States)

    Antonijevic, Nebojsa M; Zivkovic, Ivana D; Jovanovic, Ljubica M; Matic, Dragan M; Kocica, Mladen J; Mrdovic, Igor B; Kanjuh, Vladimir I; Culafic, Milica D

    2017-01-01

    The superiority of dabigatran has been well proven in the standard dosing regimen in prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF) and extended venous thromboembolism (VTE) treatment. Dabigatran, an anticoagulant with a good safety profile, reduces intracranial bleeding in patients with atrial fibrillation and decreases major and clinically relevant non-major bleeding in acute VTE treatment. However, several important clinical issues are not fully covered by currently available directions with regard to dabigatran administration. The prominent one is reflected in the fact that dynamic impairment in renal function due to dehydratation may lead to haemorragic complications on the one hand, while on the other hand glomerular hyperfiltration may be a possible cause of dabigatran subdosing, hence reducing the drug's efficacy. Furthermore, limitations of the Cockcroft-Gault formula, considered a standard equation for assessing the renal function, may imply that other calculations are likely to obtain more accurate estimates of the kidney function in specific patient populations. Method and Conclusions: Although not routinely recommended, a possibility of monitoring dabigatran in special clinical settings adds to optimization of its dosage regimens, timely perioperative care and administration of urgently demanded thrombolytic therapy, therefore significantly improving this drug's safety profile. Despite the fact that dabigatran has fewer reported interactions with drugs, food constituents, and dietary supplements, certain interactions still remain, requiring considerable caution, notably in elderly, high bleeding risk patients, patients with decreased renal function and those on complex drug regimens. Additionally, upon approval of idarucizumab, an antidote to dabigatran solution, hitherto being a major safety concern, has been finally reached, which plays a vital role in life-threatening bleeding and emergency

  17. Human Metabolism and Interactions of Deployment-Related Chemicals

    National Research Council Canada - National Science Library

    Hodgson, Ernest

    2003-01-01

    This study examines the human-metabolism and metabolic interactions of a subset of deployment-related chemicals, including chlorpyrifos, DEET, permethrin, pyridostigmine bromide, and sulfur mustard metabolites...

  18. Enantiomeric metabolic interactions and stereoselective human methadone metabolism.

    Science.gov (United States)

    Totah, Rheem A; Allen, Kyle E; Sheffels, Pamela; Whittington, Dale; Kharasch, Evan D

    2007-04-01

    Methadone is administered as a racemate, although opioid activity resides in the R-enantiomer. Methadone disposition is stereoselective, with considerable unexplained variability in clearance and plasma R/S ratios. N-Demethylation of methadone in vitro is predominantly mediated by cytochrome P450 CYP3A4 and CYP2B6 and somewhat by CYP2C19. This investigation evaluated stereoselectivity, models, and kinetic parameters for methadone N-demethylation by recombinant CYP2B6, CYP3A4, and CYP2C19, and the potential for interactions between enantiomers during racemate metabolism. CYP2B6 metabolism was stereoselective. CYP2C19 was less active, and stereoselectivity was opposite that for CYP2B6. CYP3A4 was not stereoselective. With all three isoforms, enantiomer N-dealkylation rates in the racemate were lower than those of (R)-(6-dimethyamino-4,4-diphenyl-heptan-3-one) hydrochloride (R-methadone) or (S)-(6-dimethyamino-4,4-diphenyl-heptan-3-one) hydrochloride (S-methadone) alone, suggesting an enantiomeric interaction and mutual metabolic inhibition. For CYP2B6, the interaction between enantiomers was stereoselective, with S-methadone as a more potent inhibitor of R-methadone N-demethylation than R-of S-methadone. In contrast, enantiomer interactions were not stereoselective with CYP2C19 or CYP3A4. For all three cytochromes P450, methadone N-demethylation was best described by two-site enzyme models with competitive inhibition. There were minor model differences between cytochromes P450 to account for stereoselectivity of metabolism and enantiomeric interactions. Changes in plasma R/S methadone ratios observed after rifampin or troleandomycin pretreatment in humans in vivo were successfully predicted by CYP2B6- but not CYP3A4-catalyzed methadone N-demethylation. CYP2B6 is a predominant catalyst of stereoselective methadone metabolism in vitro. In vivo, CYP2B6 may be a major determinant of methadone metabolism and disposition, and CYP2B6 activity and stereoselective metabolic

  19. Inhibition of fatty acid metabolism reduces human myeloma cells proliferation.

    Directory of Open Access Journals (Sweden)

    José Manuel Tirado-Vélez

    Full Text Available Multiple myeloma is a haematological malignancy characterized by the clonal proliferation of plasma cells. It has been proposed that targeting cancer cell metabolism would provide a new selective anticancer therapeutic strategy. In this work, we tested the hypothesis that inhibition of β-oxidation and de novo fatty acid synthesis would reduce cell proliferation in human myeloma cells. We evaluated the effect of etomoxir and orlistat on fatty acid metabolism, glucose metabolism, cell cycle distribution, proliferation, cell death and expression of G1/S phase regulatory proteins in myeloma cells. Etomoxir and orlistat inhibited β-oxidation and de novo fatty acid synthesis respectively in myeloma cells, without altering significantly glucose metabolism. These effects were associated with reduced cell viability and cell cycle arrest in G0/G1. Specifically, etomoxir and orlistat reduced by 40-70% myeloma cells proliferation. The combination of etomoxir and orlistat resulted in an additive inhibitory effect on cell proliferation. Orlistat induced apoptosis and sensitized RPMI-8226 cells to apoptosis induction by bortezomib, whereas apoptosis was not altered by etomoxir. Finally, the inhibitory effect of both drugs on cell proliferation was associated with reduced p21 protein levels and phosphorylation levels of retinoblastoma protein. In conclusion, inhibition of fatty acid metabolism represents a potential therapeutic approach to treat human multiple myeloma.

  20. Influence of multidrug resistance and drug transport proteins on chemotherapy drug metabolism.

    Science.gov (United States)

    Joyce, Helena; McCann, Andrew; Clynes, Martin; Larkin, Annemarie

    2015-05-01

    Chemotherapy involving the use of anticancer drugs remains an important strategy in the overall management of patients with metastatic cancer. Acquisition of multidrug resistance remains a major impediment to successful chemotherapy. Drug transporters in cell membranes and intracellular drug metabolizing enzymes contribute to the resistance phenotype and determine the pharmacokinetics of anticancer drugs in the body. ATP-binding cassette (ABC) transporters mediate the transport of endogenous metabolites and xenobiotics including cytotoxic drugs out of cells. Solute carrier (SLC) transporters mediate the influx of cytotoxic drugs into cells. This review focuses on the substrate interaction of these transporters, on their biology and what role they play together with drug metabolizing enzymes in eliminating therapeutic drugs from cells. The majority of anticancer drugs are substrates for the ABC transporter and SLC transporter families. Together, these proteins have the ability to control the influx and the efflux of structurally unrelated chemotherapeutic drugs, thereby modulating the intracellular drug concentration. These interactions have important clinical implications for chemotherapy because ultimately they determine therapeutic efficacy, disease progression/relapse and the success or failure of patient treatment.

  1. Redesign of the Human Metabolic Simulator

    Science.gov (United States)

    Duffield, Bruce; Jeng, Frank; Lange, Kevin

    2004-01-01

    The National Aeronautics and Space Administration (NASA) is currently building a Human Metabolic Simulator (HMS) at the Johnson Space Center as part of the Advanced Life Support Air Revitalization Technology Evaluation Facility (ARTEF). The purpose of ARTEF is to evaluate Environmental Control and Life Support System Technologies for Advanced Missions. The HMS is needed to reproduce the primary metabolic effects of human respiration on an enclosed atmosphere when humans cannot be present and the impact of human presence on the system is required. A HMS was designed, built and successfully operated in 2000 but larger crew size requirements and the expense of upgrade of the current system necessitate redesign. This paper addresses the redesign. Several concepts were considered, ranging from chemical oxidation of a hydrocarbon like ethanol or ethyl acetate to carbon dioxide and water, oxidation of an iron-containing compound, or by using a fuel cell. For reasons of cost, simplicity, safety and other factors, the concept chosen includes: a molecular sieve packaged as an industrial oxygen concentrator to remove oxygen from the atmosphere, with direct carbon dioxide, water and heat injection. The water injection is done via heating water to steam with a heat exchanger and thermal effects are handled by directly adding heat to the air stream with a second heat exchanger. Both heat exchangers are supplied by a hot oil loop. The amount of oxygen removal, carbon dioxide addition, water addition and heat addition were calculated using metabolic profiles for respiration and heat, calculated using a series of empirical equations developed for International Space Station (ISS). Sketches of the Human Metabolic Simulator and the hot oil bath loop used to supply heat to the heat exchangers are included

  2. Energy Metabolism and Human Dosimetry of Tritium

    International Nuclear Information System (INIS)

    Galeriu, D.; Takeda, H.; Melintescu, A.; Trivedi, A.

    2005-01-01

    In the frame of current revision of human dosimetry of 14 C and tritium, undertaken by the International Commission of Radiological Protection, we propose a novel approach based on energy metabolism and a simple biokinetic model for the dynamics of dietary intake (organic 14 C, tritiated water and Organically Bound Tritium-OBT). The model predicts increased doses for HTO and OBT comparing to ICRP recommendations, supporting recent findings

  3. Interconnectivity of human cellular metabolism and disease prevalence

    International Nuclear Information System (INIS)

    Lee, Deok-Sun

    2010-01-01

    Fluctuations of metabolic reaction fluxes may cause abnormal concentrations of toxic or essential metabolites, possibly leading to metabolic diseases. The mutual binding of enzymatic proteins and ones involving common metabolites enforces distinct coupled reactions, by which local perturbations may spread through the cellular network. Such network effects at the molecular interaction level in human cellular metabolism can reappear in the patterns of disease occurrence. Here we construct the enzyme-reaction network and the metabolite-reaction network, capturing the flux coupling of metabolic reactions caused by the interacting enzymes and the shared metabolites, respectively. Diseases potentially caused by the failure of individual metabolic reactions can be identified by using the known disease–gene association, which allows us to derive the probability of an inactivated reaction causing diseases from the disease records at the population level. We find that the greater the number of proteins that catalyze a reaction, the higher the mean prevalence of its associated diseases. Moreover, the number of connected reactions and the mean size of the avalanches in the networks constructed are also shown to be positively correlated with the disease prevalence. These findings illuminate the impact of the cellular network topology on disease development, suggesting that the global organization of the molecular interaction network should be understood to assist in disease diagnosis, treatment, and drug discovery

  4. Interconnectivity of human cellular metabolism and disease prevalence

    Science.gov (United States)

    Lee, Deok-Sun

    2010-12-01

    Fluctuations of metabolic reaction fluxes may cause abnormal concentrations of toxic or essential metabolites, possibly leading to metabolic diseases. The mutual binding of enzymatic proteins and ones involving common metabolites enforces distinct coupled reactions, by which local perturbations may spread through the cellular network. Such network effects at the molecular interaction level in human cellular metabolism can reappear in the patterns of disease occurrence. Here we construct the enzyme-reaction network and the metabolite-reaction network, capturing the flux coupling of metabolic reactions caused by the interacting enzymes and the shared metabolites, respectively. Diseases potentially caused by the failure of individual metabolic reactions can be identified by using the known disease-gene association, which allows us to derive the probability of an inactivated reaction causing diseases from the disease records at the population level. We find that the greater the number of proteins that catalyze a reaction, the higher the mean prevalence of its associated diseases. Moreover, the number of connected reactions and the mean size of the avalanches in the networks constructed are also shown to be positively correlated with the disease prevalence. These findings illuminate the impact of the cellular network topology on disease development, suggesting that the global organization of the molecular interaction network should be understood to assist in disease diagnosis, treatment, and drug discovery.

  5. Integration of genome-scale metabolic networks into whole-body PBPK models shows phenotype-specific cases of drug-induced metabolic perturbation.

    Science.gov (United States)

    Cordes, Henrik; Thiel, Christoph; Baier, Vanessa; Blank, Lars M; Kuepfer, Lars

    2018-01-01

    Drug-induced perturbations of the endogenous metabolic network are a potential root cause of cellular toxicity. A mechanistic understanding of such unwanted side effects during drug therapy is therefore vital for patient safety. The comprehensive assessment of such drug-induced injuries requires the simultaneous consideration of both drug exposure at the whole-body and resulting biochemical responses at the cellular level. We here present a computational multi-scale workflow that combines whole-body physiologically based pharmacokinetic (PBPK) models and organ-specific genome-scale metabolic network (GSMN) models through shared reactions of the xenobiotic metabolism. The applicability of the proposed workflow is illustrated for isoniazid, a first-line antibacterial agent against Mycobacterium tuberculosis , which is known to cause idiosyncratic drug-induced liver injuries (DILI). We combined GSMN models of a human liver with N-acetyl transferase 2 (NAT2)-phenotype-specific PBPK models of isoniazid. The combined PBPK-GSMN models quantitatively describe isoniazid pharmacokinetics, as well as intracellular responses, and changes in the exometabolome in a human liver following isoniazid administration. Notably, intracellular and extracellular responses identified with the PBPK-GSMN models are in line with experimental and clinical findings. Moreover, the drug-induced metabolic perturbations are distributed and attenuated in the metabolic network in a phenotype-dependent manner. Our simulation results show that a simultaneous consideration of both drug pharmacokinetics at the whole-body and metabolism at the cellular level is mandatory to explain drug-induced injuries at the patient level. The proposed workflow extends our mechanistic understanding of the biochemistry underlying adverse events and may be used to prevent drug-induced injuries in the future.

  6. Studies on the metabolism of the α-pyrrolidinophenone designer drug methylenedioxy-pyrovalerone (MDPV) in rat and human urine and human liver microsomes using GC-MS and LC-high-resolution MS and its detectability in urine by GC-MS.

    Science.gov (United States)

    Meyer, Markus R; Du, Peng; Schuster, Frank; Maurer, Hans H

    2010-12-01

    Since the late 1990s, many derivatives of the α-pyrrolidinophenone (PPP) drug class appeared on the drugs of abuse market. The latest compound was described in 2009 to be a classic PPP carrying a methylenedioxy moiety remembering the classic entactogens (ecstasy). Besides Germany, 3,4-methylene-dioxypyrovalerone (MDPV) has appeared in many countries in Europe and Asia, indicating its worldwide importance for forensic and clinical toxicology. The aim of the presented work was to identify the phase I and II metabolites of MDPV and the human cytochrome-P450 (CYP) isoenzymes responsible for its main metabolic step(s). Finally, the detectability of MDPV in urine by the authors' systematic toxicological analysis (STA) should be studied. The urine samples were extracted after and without enzymatic cleavage of conjugates. The metabolites were separated and identified after work-up by GC-MS and liquid chromatography (LC)-high-resolution MS (LC-HR-MS). The studies revealed the following phase I main metabolic steps in rat and human: demethylenation followed by methylation, aromatic and side chain hydroxylation and oxidation of the pyrrolidine ring to the corresponding lactam as well as ring opening to the corresponding carboxylic acid. Using LC-HR-MS, most metabolite structures postulated according to GC-MS fragmentation could be confirmed and the phase II metabolites were identified. Finally, the formation of the initial metabolite demethylenyl-MDPV could be confirmed using incubation of human liver microsomes. Using recombinant human CYPs, CYP 2C19, CYP 2D6 and CYP 1A2 were found to catalyze this initial step. Finally, the STA allowed the detection of MDPV metabolites in the human urine samples. Copyright © 2010 John Wiley & Sons, Ltd.

  7. Drug interactions at the human placenta: what is the evidence?

    Directory of Open Access Journals (Sweden)

    Miriam eRubinchik-Stern

    2012-07-01

    Full Text Available Pregnant women (and their fetuses are treated with a significant number of prescription and nonprescription medications. Interactions among those drugs may affect their efficacy and toxicity in both mother and fetus. Whereas interactions that result in altered drug concentrations in maternal plasma are detectable, those involving modulation of placental transfer mechanisms are rarely reflected by altered drug concentrations in maternal plasma. Therefore, they are often overlooked. Placental-mediated interactions are possible because the placenta is not only a passive diffusional barrier, but also expresses a variety of influx and efflux transporters and drug metabolizing enzymes. Current data on placental-mediated drug interactions are limited. In rodents, pharmacological or genetic manipulations of placental transporters significantly affect fetal drug exposure. In contrast, studies in human placentae suggest that the magnitude of such interactions is modest in most cases. Nevertheless, under certain circumstances, such interactions may be of clinical significance. This review describes currently known mechanisms of placental-mediated drug interactions and the potential implications of such interactions in humans. Better understanding of those mechanisms is important for minimizing fetal toxicity from drugs while improving their efficacy when directed to treat the fetus.

  8. Metabolism of gentiopicroside (gentiopicrin) by human intestinal bacteria.

    Science.gov (United States)

    el-Sedawy, A I; Hattori, M; Kobashi, K; Namba, T

    1989-09-01

    As a part of our studies on the metabolism of crude drug components by intestinal bacteria, gentiopicroside (a secoiridoid glucoside isolated from Gentiana lutea), was anaerobically incubated with various defined strains of human intestinal bacteria. Many species had ability to transform it to a series of metabolites. Among them, Veillonella parvula ss parvula produced five metabolites, which were identified as erythrocentaurin, gentiopicral, 5-hydroxymethylisochroman-1-one,5-hydroxymethylisochromen-1- one and trans-5,6-dihydro-5-hydroxymethyl-6-methyl-1H,3H-pyrano[3,4-c]pyra n-1-one.

  9. Antimalarial drug targets in Plasmodium falciparum predicted by stage-specific metabolic network analysis

    Directory of Open Access Journals (Sweden)

    Huthmacher Carola

    2010-08-01

    Full Text Available Abstract Background Despite enormous efforts to combat malaria the disease still afflicts up to half a billion people each year of which more than one million die. Currently no approved vaccine is available and resistances to antimalarials are widely spread. Hence, new antimalarial drugs are urgently needed. Results Here, we present a computational analysis of the metabolism of Plasmodium falciparum, the deadliest malaria pathogen. We assembled a compartmentalized metabolic model and predicted life cycle stage specific metabolism with the help of a flux balance approach that integrates gene expression data. Predicted metabolite exchanges between parasite and host were found to be in good accordance with experimental findings when the parasite's metabolic network was embedded into that of its host (erythrocyte. Knock-out simulations identified 307 indispensable metabolic reactions within the parasite. 35 out of 57 experimentally demonstrated essential enzymes were recovered and another 16 enzymes, if additionally the assumption was made that nutrient uptake from the host cell is limited and all reactions catalyzed by the inhibited enzyme are blocked. This predicted set of putative drug targets, shown to be enriched with true targets by a factor of at least 2.75, was further analyzed with respect to homology to human enzymes, functional similarity to therapeutic targets in other organisms and their predicted potency for prophylaxis and disease treatment. Conclusions The results suggest that the set of essential enzymes predicted by our flux balance approach represents a promising starting point for further drug development.

  10. Drug metabolism and pharmacokinetic diversity of ranunculaceae medicinal compounds.

    Science.gov (United States)

    Hao, Da-Cheng; Ge, Guang-Bo; Xiao, Pei-Gen; Wang, Ping; Yang, Ling

    2015-01-01

    The wide-reaching distributed angiosperm family Ranunculaceae has approximately 2200 species in around 60 genera. Chemical components of this family include several representative groups: benzylisoquinoline alkaloid (BIA), ranunculin, triterpenoid saponin and diterpene alkaloid, etc. Their extensive clinical utility has been validated by traditional uses of thousands of years and current evidence-based medicine studies. Drug metabolism and pharmacokinetic (DMPK) studies of plant-based natural products are an indispensable part of comprehensive medicinal plant exploration, which could facilitate conservation and sustainable utilization of Ranunculaceae pharmaceutical resources, as well as new chemical entity development with improved DMPK parameters. However, DMPK characteristics of Ranunculaceaederived medicinal compounds have not been summarized. Black cohosh (Cimicifuga) and goldenseal (Hydrastis) raise concerns of herbdrug interaction. DMPK studies of other Ranunculaceae genera, e.g., Nigella, Delphinium, Aconitum, Trollius, and Coptis, are also rapidly increasing and becoming more and more clinically relevant. In this contribution, we highlight the up-to-date awareness, as well as the challenges around the DMPK-related issues in optimization of drug development and clinical practice of Ranunculaceae compounds. Herb-herb interaction of Ranunculaceae herb-containing traditional Chinese medicine (TCM) formula could significantly influence the in vivo pharmacokinetic behavior of compounds thereof, which may partially explain the complicated therapeutic mechanism of TCM formula. Although progress has been made on revealing the absorption, distribution, metabolism, excretion and toxicity (ADME/T) of Ranunculaceae compounds, there is a lack of DMPK studies of traditional medicinal genera Aquilegia, Thalictrum and Clematis. Fluorescent probe compounds could be promising substrate, inhibitor and/or inducer in future DMPK studies of Ranunculaceae compounds. A better

  11. Metabolism of anabolic steroids and their relevance to drug detection in horseracing.

    Science.gov (United States)

    Teale, Philip; Houghton, Edward

    2010-06-01

    The fight against doping in sport using analytical chemistry is a mature area with a history of approximately 100 years in horseracing. In common with human sport, anabolic/androgenic steroids (AASs) are an important group of potential doping agents. Particular issues with their detection are extensive metabolism including both phase I and phase II. A number of the common AASs are also endogenous to the equine. A further issue is the large number of synthetic steroids produced as pharmaceutical products or as 'designer' drugs intended to avoid detection or for the human supplement market. An understanding of the metabolism of AASs is vital to the development of effective detection methods for equine sport. The aim of this paper is to review current knowledge of the metabolism of appropriate steroids, the current approaches to their detection in equine sport and future trends that may affect equine dope testing.

  12. Impact of Drug Metabolism/Pharmacokinetics and Their Relevance upon Taxus-based Drug Development.

    Science.gov (United States)

    Hao, Da-Cheng; Ge, Guang-Bo; Wang, Ping; Yang, Ling

    2018-05-22

    Drug metabolism and pharmacokinetic (DMPK) studies of Taxus natural products, their semi-synthetic derivatives and analogs are indispensable in the optimization of lead compounds and clinical therapy. These studies can lead to development of new drug entities with improved absorption, distribution, metabolism, excretion and toxicity (ADME/T) profiles. To date, there have been no comprehensive reviews of the DMPK features of Taxus derived medicinal compounds.Natural and semi-synthetic taxanes may cause and could be affected by drug-drug interaction (DDI). Hence ADME/T studies of various taxane-containing formulations are important; to date these studies indicate that the role of cytochrome p450s and drug transporters is more prominent than phase II drug metabolizing enzymes. Mechanisms of taxane DMPK mediated by nuclear receptors, microRNAs, and single nucleotide polymorphisms are being revealed. Herein we review the latest knowledge on these topics, as well as the gaps in knowledge of the DMPK issues of Taxus compounds. DDIs significantly impact the PK/pharmacodynamics performance of taxanes and co-administered chemicals, which may inspire researchers to develop novel formula. While the ADME/T profiles of some taxanes are well defined, DMPK studies should be extended to more Taxus compounds, species, and Taxus -involved formulations, which would be streamlined by versatile omics platforms and computational analyses. Further biopharmaceutical investigations will be beneficial tothe translation of bench findings to the clinical applications. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Flavonoids as modulators of metabolic enzymes and drug transporters.

    Science.gov (United States)

    Miron, Anca; Aprotosoaie, Ana Clara; Trifan, Adriana; Xiao, Jianbo

    2017-06-01

    Flavonoids, natural compounds found in plants and in plant-derived foods and beverages, have been extensively studied with regard to their capacity to modulate metabolic enzymes and drug transporters. In vitro, flavonoids predominantly inhibit the major phase I drug-metabolizing enzyme CYP450 3A4 and the enzymes responsible for the bioactivation of procarcinogens (CYP1 enzymes) and upregulate the enzymes involved in carcinogen detoxification (UDP-glucuronosyltransferases, glutathione S-transferases (GSTs)). Flavonoids have been reported to inhibit ATP-binding cassette (ABC) transporters (multidrug resistance (MDR)-associated proteins, breast cancer-resistance protein) that contribute to the development of MDR. P-glycoprotein, an ABC transporter that limits drug bioavailability and also induces MDR, was differently modulated by flavonoids. Flavonoids and their phase II metabolites (sulfates, glucuronides) inhibit organic anion transporters involved in the tubular uptake of nephrotoxic compounds. In vivo studies have partially confirmed in vitro findings, suggesting that the mechanisms underlying the modulatory effects of flavonoids are complex and difficult to predict in vivo. Data summarized in this review strongly support the view that flavonoids are promising candidates for the enhancement of oral drug bioavailability, chemoprevention, and reversal of MDR. © 2017 New York Academy of Sciences.

  14. Metabolic drug interactions - the impact of prescribed drug regimens on the medication safety.

    NARCIS (Netherlands)

    Fialova, D.; Vrbensky, K.; Topinkova, E.; Vlcek, J.; Soerbye, L.W.; Wagner, C.; Bernabei, R.

    2005-01-01

    Background and objective: Risk/benefit profile of prescribed drug regimens is unkown. Over 60% of commonly used medications interact on metabolic pathways (cytochrom P450 (CYP450), uridyl-glucuronyl tranferasis (UGT I, II) and P-glycoprotein (PGP) transport). Using an up-to-date knowledge on

  15. Variability in human metabolism of arsenic

    International Nuclear Information System (INIS)

    Loffredo, C.A.; Aposhian, H.V.; Cebrian, M.E.; Yamauchi, Hiroshi; Silbergeld, E.K.

    2003-01-01

    Estimating the nature and extent of human cancer risks due to arsenic (As) in drinking water is currently of great concern, since millions of persons worldwide are exposed to arsenic, primarily through natural enrichment of drinking water drawn from deep wells. Humans metabolize and eliminate As through oxidative methylation and subsequent urinary excretion. While there is debate as to the role of methylation in activation/detoxification, variations in arsenic metabolism may affect individual risks of toxicity and carcinogenesis. Using data from three populations, from Mexico, China, and Chile, we have analyzed the distribution in urine of total arsenic and arsenic species (inorganic arsenic (InAs), monomethyl arsenic (MMA), and dimethyl arsenic (DMA). Data were analyzed in terms of the concentration of each species and by evaluating MMA:DMA and (MMA+DMA):InAs ratios. In all persons most urinary As was present as DMA. Male:female differences were discernible in both high- and low-exposure groups from all three populations, but the gender differences varied by populations. The data also indicated bimodal distributions in the ratios of DMA to InAs and to MMA. While the gene or genes responsible for arsenic methylation are still unknown, the results of our studies among the ethnic groups in this study are consistent with the presence of functional genetic polymorphisms in arsenic methylation leading to measurable differences in toxicity. This analysis highlights the need for continuing research on the health effects of As in humans using molecular epidemiologic methods

  16. Pharmacogenetic screening for polymorphisms in drug-metabolizing enzymes and drug transporters in a Dutch population.

    Science.gov (United States)

    Bosch, T M; Doodeman, V D; Smits, P H M; Meijerman, I; Schellens, J H M; Beijnen, J H

    2006-01-01

    A possible explanation for the wide interindividual variability in toxicity and efficacy of drug therapy is variation in genes encoding drug-metabolizing enzymes and drug transporters. The allelic frequency of these genetic variants, linkage disequilibrium (LD), and haplotype of these polymorphisms are important parameters in determining the genetic differences between patients. The aim of this study was to explore the frequencies of polymorphisms in drug-metabolizing enzymes (CYP1A1, CYP2C9, CYP2C19, CYP3A4, CYP2D6, CYP3A5, DPYD, UGT1A1, GSTM1, GSTP1, GSTT1) and drug transporters (ABCB1[MDR1] and ABCC2[MRP2]), and to investigate the LD and perform haplotype analysis of these polymorphisms in a Dutch population. Blood samples were obtained from 100 healthy volunteers and genomic DNA was isolated and amplified by PCR. The amplification products were sequenced and analyzed for the presence of polymorphisms by sequence alignment. In the study population, we identified 13 new single nucleotide polymorphisms (SNPs) in Caucasians and three new SNPs in non-Caucasians, in addition to previously recognized SNPs. Three of the new SNPs were found within exons, of which two resulted in amino acid changes (A428T in CYP2C9 resulting in the amino acid substitution D143V; and C4461T in ABCC2 in a non-Caucasian producing the amino acid change T1476M). Several LDs and haplotypes were found in the Caucasian individuals. In this Dutch population, the frequencies of 16 new SNPs and those of previously recognized SNPs were determined in genes coding for drug-metabolizing enzymes and drug transporters. Several LDs and haplotypes were also inferred. These data are important for further research to help explain the interindividual pharmacokinetic and pharmacodynamic variability in response to drug therapy.

  17. Hyperthyroidism increases brown fat metabolism in humans.

    Science.gov (United States)

    Lahesmaa, Minna; Orava, Janne; Schalin-Jäntti, Camilla; Soinio, Minna; Hannukainen, Jarna C; Noponen, Tommi; Kirjavainen, Anna; Iida, Hidehiro; Kudomi, Nobuyuki; Enerbäck, Sven; Virtanen, Kirsi A; Nuutila, Pirjo

    2014-01-01

    Thyroid hormones are important regulators of brown adipose tissue (BAT) development and function. In rodents, BAT metabolism is up-regulated by thyroid hormones. The purpose of this article was to investigate the impact of hyperthyroidism on BAT metabolism in humans. This was a follow-up study using positron emission tomography imaging. Glucose uptake (GU) and perfusion of BAT, white adipose tissue, skeletal muscle, and thyroid gland were measured using [18F]2-fluoro-2-deoxy-D-glucose and [15O]H2O and positron emission tomography in 10 patients with overt hyperthyroidism and in 8 healthy participants. Five of the hyperthyroid patients were restudied after restoration of euthyroidism. Supraclavicular BAT was quantified with magnetic resonance imaging or computed tomography and energy expenditure (EE) with indirect calorimetry. Compared with healthy participants, hyperthyroid participants had 3-fold higher BAT GU (2.7±2.3 vs 0.9±0.1 μmol/100 g/min, P=.0013), 90% higher skeletal muscle GU (Phyperthyroidism, serum free T4 and free T3 were strongly associated with EE and lipid oxidation rates (Pmetabolism (PHyperthyroidism had no effect on BAT perfusion, whereas it stimulated skeletal muscle perfusion (P=.04). Thyroid gland GU did not differ between hyperthyroid and euthyroid study subjects. Hyperthyroidism increases GU in BAT independently of BAT perfusion. Hyperthyroid patients are characterized by increased skeletal muscle metabolism and lipid oxidation rates.

  18. Effect of the anticarcinogenic drug 6-mercaptopurine on mineral metabolism

    International Nuclear Information System (INIS)

    Amemiya, K.

    1987-01-01

    The effect of 6-mercaptopurine (6-MP) on mineral metabolism was investigated using rats and mice. A single 6-mercaptopurine injection in pregnant rats on day 11 of gestation proved to be highly teratogenic. At term, fetuses from 6-MP injected dams had lower livers zinc concentrations than non-injected or vehicle injected controls while dams showed no differences in liver zinc. Fetuses from dams injected with 6-MP and fed supplemental levels of zinc had a lower frequency of malformations and had higher hepatic zinc concentrations than fetuses from dams fed less zinc with drug injection. Non-pregnant mice injected with 6-MP had higher zinc concentrations compared to controls. In addition, iron, copper and calcium concentrations were higher in the livers of 6-MP injected mice than in controls, indicating that the drug affected several elements. Hepatic concentrations of metallothionein (MT) were also elevated in 6-MP injected mice, suggesting that the change in zinc concentrations associated with drug administration was the result of a drug induction of MT. Dams injected with 6-MP on day 13 of pregnancy had livers which retained more of an absorbed dose of 65 zinc than non-injected dams. Plasma from these drug injected dams also retained less of the absorbed dose than control dams. In contrast, day 14 from dams injected with 6-MP, retained less of an absorbed dose than control embryos

  19. Radioiodine 131I metabolism in human

    International Nuclear Information System (INIS)

    Mori, Toru

    1976-01-01

    Metabolic fate of orally administered 131 I in human was studied. Chronological observations of whole body radioactivity distribution and thyroid 131 I uptake curve revealed that 131 I metabolism was greatly affected by the amount of dietary iodine intake. Under the high iodine intake exceeding 1 mg per day, uptake curve showed biphasic descending type, that is, rapid accumulation during 3 to 6 hours and rapid fall up to 48 hours and gradual decrease afterwards. While, ascending type, monophasic and maximal at 24 hours, was found universary under low iodine intake less than 500 μg per day. Thyroid function should not be affected by the amount of iodine intake, and we analysed 131 I metabolism using a new four compartments which included intrathyroidal inorganic iodine pool. The results, especially hormone production rate, were found quite useful even under high iodine intake. Thyroidal organic iodine contents were calculated as approximately 2.5 mg and this value was much less than previously reported values from other countries. Administered radioiodine were mixed up with stable body iodine and reached equilibration by around 10 days. From seroimmunological, histological (microscopic and electron microscopic) studies, and irradiation studies to the cultured human thyroid cells, we concluded that this unexpected phenomenon was derived from chromosomal damage which induced gradual decrease in cell population because of inability to reproduce. Carcinogenic and genetic effects were not serious, and only three leukemic patients were reported in this country and 484 normal babies were born from 7,500 treated parents. Thus, therapeutic dose of 131 I was proved rather safe, and even when exposed to radioiodine, administration of perchlorate or thiocyanate, excessive iodine and TSH seemed effective to avoid radiation injuries. (auth.)

  20. Drug-drug interaction and doping, part 1: an in vitro study on the effect of non-prohibited drugs on the phase I metabolic profile of toremifene.

    Science.gov (United States)

    Mazzarino, Monica; de la Torre, Xavier; Fiacco, Ilaria; Palermo, Amelia; Botrè, Francesco

    2014-05-01

    The present study was designed to provide preliminary information on the potential impact of metabolic drug-drug interaction on the effectiveness of doping control strategies currently followed by the anti-doping laboratories to detect the intake of banned agents. In vitro assays based on the use of human liver microsomes and recombinant CYP isoforms were designed and performed to characterize the phase I metabolic profile of the prohibited agent toremifene, selected as a prototype drug of the class of selective oestrogen receptor modulators, both in the absence and in the presence of medicaments (fluconazole, ketoconazole, itraconazole, miconazole, cimetidine, ranitidine, fluoxetine, paroxetine, nefazodone) not included in the World Anti-Doping Agency list of prohibited substances and methods and frequently administered to athletes. The results show that the in vitro model developed in this study was adequate to simulate the in vivo metabolism of toremifene, confirming the results obtained in previous studies. Furthermore, our data also show that ketoconazole, itraconazole, miconazole and nefazodone cause a marked modification in the production of the metabolic products (i.e. hydroxylated and carboxylated metabolites) normally selected by the anti-doping laboratories as target analytes to detect toremifene intake; moderate variations were registered in the presence of fluconazole, paroxetine and fluoxetine; while no significant modifications were measured in the presence of ranitidine and cimetidine. This evidence imposes that the potential effect of drug-drug interactions is duly taken into account in anti-doping analysis, also for a broader significance of the analytical results. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Use of density functional theory in drug metabolism studies

    DEFF Research Database (Denmark)

    Rydberg, Patrik; Jørgensen, Flemming Steen; Olsen, Lars

    2014-01-01

    INTRODUCTION: The cytochrome P450 enzymes (CYPs) metabolize many drug compounds. They catalyze a wide variety of reactions, and potentially, a large number of different metabolites can be generated. Density functional theory (DFT) has, over the past decade, been shown to be a powerful tool...... isoforms. This is probably due to the fact that the binding of the substrates is not the major determinant. When binding of the substrate plays a significant role, the well-known issue of determining the free energy of binding is the challenge. How approaches taking the protein environment into account...

  2. Targeting the latest hallmark of cancer: another attempt at 'magic bullet' drugs targeting cancers' metabolic phenotype.

    Science.gov (United States)

    Cuperlovic-Culf, M; Culf, A S; Touaibia, M; Lefort, N

    2012-10-01

    The metabolism of tumors is remarkably different from the metabolism of corresponding normal cells and tissues. Metabolic alterations are initiated by oncogenes and are required for malignant transformation, allowing cancer cells to resist some cell death signals while producing energy and fulfilling their biosynthetic needs with limiting resources. The distinct metabolic phenotype of cancers provides an interesting avenue for treatment, potentially with minimal side effects. As many cancers show similar metabolic characteristics, drugs targeting the cancer metabolic phenotype are, perhaps optimistically, expected to be 'magic bullet' treatments. Over the last few years there have been a number of potential drugs developed to specifically target cancer metabolism. Several of these drugs are currently in clinical and preclinical trials. This review outlines examples of drugs developed for different targets of significance to cancer metabolism, with a focus on small molecule leads, chemical biology and clinical results for these drugs.

  3. 21 CFR 25.31 - Human drugs and biologics.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Human drugs and biologics. 25.31 Section 25.31 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ENVIRONMENTAL IMPACT CONSIDERATIONS Categorical Exclusions § 25.31 Human drugs and biologics. The classes of...

  4. Precision-cut intestinal slices: alternative model for drug transport, metabolism, and toxicology research.

    Science.gov (United States)

    Li, Ming; de Graaf, Inge A M; Groothuis, Geny M M

    2016-01-01

    The absorption, distribution, metabolism, excretion and toxicity (ADME-tox) processes of drugs are of importance and require preclinical investigation intestine in addition to the liver. Various models have been developed for prediction of ADME-tox in the intestine. In this review, precision-cut intestinal slices (PCIS) are discussed and highlighted as model for ADME-tox studies. This review provides an overview of the applications and an update of the most recent research on PCIS as an ex vivo model to study the transport, metabolism and toxicology of drugs and other xenobiotics. The unique features of PCIS and the differences with other models as well as the translational aspects are also discussed. PCIS are a simple, fast, and reliable ex vivo model for drug ADME-tox research. Therefore, PCIS are expected to become an indispensable link in the in vitro-ex vivo-in vivo extrapolation, and a bridge in translation of animal data to the human situation. In the future, this model may be helpful to study the effects of interorgan interactions, intestinal bacteria, excipients and drug formulations on the ADME-tox properties of drugs. The optimization of culture medium and the development of a (cryo)preservation technique require more research.

  5. Bone blood flow and metabolism in humans

    DEFF Research Database (Denmark)

    Heinonen, Ilkka; Kemppainen, Jukka; Kaskinoro, Kimmo

    2012-01-01

    Human bone blood flow and metabolism during physical exercise remains poorly characterised. In the present study we measured femoral bone blood flow and glucose uptake in young healthy subjects by positron emission tomography in three separate protocols. In six women, blood flow was measured...... in femoral bone at rest and during one leg intermittent isometric exercise with increasing exercise intensities. In nine men, blood flow in femur was determined at rest and during dynamic one leg exercise, and two other physiological perturbations: moderate systemic hypoxia (14 O(2) ) at rest and during...... exercise, and during intra-femoral infusion of high-dose adenosine. Bone glucose uptake was measured at rest and during dynamic one leg exercise in five men. The results indicate that isometric exercise increased femoral bone blood flow from rest (1.8 ± 0.6 ml/100g/min) to low intensity exercise (4.1 ± 1...

  6. Evidence that humans metabolize benzene via two pathways.

    NARCIS (Netherlands)

    Rappaport, S.M.; Kim, S.; Lan, Q.; Vermeulen, R.C.H.; Waidyanatha, S.; Zhang, L.; Li, G.; Yin, S.; Hayes, R.B.; Rothman, N.; Smith, M.T.

    2009-01-01

    BACKGROUND: Recent evidence has shown that humans metabolize benzene more efficiently at environmental air concentrations than at concentrations > 1 ppm. This led us to speculate that an unidentified metabolic pathway was mainly responsible for benzene metabolism at ambient levels. OBJECTIVE: We

  7. Dose-response effects of lycopene on selected drug-metabolizing and antioxidant enzymes in the rat

    DEFF Research Database (Denmark)

    Breinholt, V.; Lauridsen, S. T.; Daneshvar, B.

    2000-01-01

    to be affected by prior. lycopene exposure. The level of PhIP-DNA adducts in the liver or colon was likewise not affected by lycopene at any dose. Overall, the present study provides evidence that lycopene administered in the diet of young female rats exerts minor modifying effects toward antioxidant and drug......-metabolizing enzymes involved in the protection against oxidative stress and cancer. The fact that these enzymatic activities are induced at all of these very low plasma levels, could be taken to suggest that modulation of antioxidant and drug-metabolizing enzymes map indeed be relevant to humans, which in general...

  8. Detection of driver metabolites in the human liver metabolic network using structural controllability analysis

    Science.gov (United States)

    2014-01-01

    Background Abnormal states in human liver metabolism are major causes of human liver diseases ranging from hepatitis to hepatic tumor. The accumulation in relevant data makes it feasible to derive a large-scale human liver metabolic network (HLMN) and to discover important biological principles or drug-targets based on network analysis. Some studies have shown that interesting biological phenomenon and drug-targets could be discovered by applying structural controllability analysis (which is a newly prevailed concept in networks) to biological networks. The exploration on the connections between structural controllability theory and the HLMN could be used to uncover valuable information on the human liver metabolism from a fresh perspective. Results We applied structural controllability analysis to the HLMN and detected driver metabolites. The driver metabolites tend to have strong ability to influence the states of other metabolites and weak susceptibility to be influenced by the states of others. In addition, the metabolites were classified into three classes: critical, high-frequency and low-frequency driver metabolites. Among the identified 36 critical driver metabolites, 27 metabolites were found to be essential; the high-frequency driver metabolites tend to participate in different metabolic pathways, which are important in regulating the whole metabolic systems. Moreover, we explored some other possible connections between the structural controllability theory and the HLMN, and find that transport reactions and the environment play important roles in the human liver metabolism. Conclusion There are interesting connections between the structural controllability theory and the human liver metabolism: driver metabolites have essential biological functions; the crucial role of extracellular metabolites and transport reactions in controlling the HLMN highlights the importance of the environment in the health of human liver metabolism. PMID:24885538

  9. Quantum Mechanics/Molecular Mechanics Modeling of Drug Metabolism

    DEFF Research Database (Denmark)

    Lonsdale, Richard; Fort, Rachel M; Rydberg, Patrik

    2016-01-01

    )-mexiletine in CYP1A2 with hybrid quantum mechanics/molecular mechanics (QM/MM) methods, providing a more detailed and realistic model. Multiple reaction barriers have been calculated at the QM(B3LYP-D)/MM(CHARMM27) level for the direct N-oxidation and H-abstraction/rebound mechanisms. Our calculated barriers......The mechanism of cytochrome P450(CYP)-catalyzed hydroxylation of primary amines is currently unclear and is relevant to drug metabolism; previous small model calculations have suggested two possible mechanisms: direct N-oxidation and H-abstraction/rebound. We have modeled the N-hydroxylation of (R...... indicate that the direct N-oxidation mechanism is preferred and proceeds via the doublet spin state of Compound I. Molecular dynamics simulations indicate that the presence of an ordered water molecule in the active site assists in the binding of mexiletine in the active site...

  10. Sirtuins: Novel targets for metabolic disease in drug development

    International Nuclear Information System (INIS)

    Jiang Weijian

    2008-01-01

    Calorie restriction extends lifespan and produces a metabolic profile desirable for treating diseases such as type 2 diabetes. SIRT1, an NAD + -dependent deacetylase, is a principal modulator of pathways downstream of calorie restriction that produces beneficial effects on glucose homeostasis and insulin sensitivity. Activation of SIRT1 leads to enhanced activity of multiple proteins, including peroxisome proliferator-activated receptor coactivator-1α (PGC-1α) and FOXO which helps to mediate some of the in vitro and in vivo effects of sirtuins. Resveratrol, a polyphenolic SIRT1 activator, mimics the effects of calorie restriction in lower organisms and in mice fed a high-fat diet ameliorates insulin resistance. In this review, we summarize recent research advances in unveiling the molecular mechanisms that underpin sirtuin as therapeutic candidates and discuss the possibility of using resveratrol as potential drug for treatment of diabetes

  11. Towards metabolic mapping of the human retina.

    Science.gov (United States)

    Schweitzer, D; Schenke, S; Hammer, M; Schweitzer, F; Jentsch, S; Birckner, E; Becker, W; Bergmann, A

    2007-05-01

    Functional alterations are first signs of a starting pathological process. A device that measures parameter for the characterization of the metabolism at the human eye-ground would be a helpful tool for early diagnostics in stages when alterations are yet reversible. Measurements of blood flow and of oxygen saturation are necessary but not sufficient. The new technique of auto-fluorescence lifetime measurement (FLIM) opens in combination with selected excitation and emission ranges the possibility for metabolic mapping. FLIM not only adds an additional discrimination parameter to distinguish different fluorophores but also resolves different quenching states of the same fluorophore. Because of its high sensitivity and high temporal resolution, its capability to resolve multi-exponential decay functions, and its easy combination with laser scanner ophthalmoscopy, multi-dimensional time-correlated single photon counting was used for fundus imaging. An optimized set up for in vivo lifetime measurements at the human eye-ground will be explained. In this, the fundus fluorescence is excited at 446 or 468 nm and the time-resolved autofluorescence is detected in two spectral ranges between 510 and 560 nm as well as between 560 and 700 nm simultaneously. Exciting the fundus at 446 nm, several fluorescence maxima of lifetime t1 were detected between 100 and 220 ps in lifetime histograms of 40 degrees fundus images. In contrast, excitation at 468 nm results in a single maximum of lifetime t1 = 190 +/- 16 ps. Several fundus layers contribute to the fluorescence intensity in the short-wave emission range 510-560 nm. In contrast, the fluorescence intensity in the long-wave emission range between 560 and 700 nm is dominated by the fluorescence of lipofuscin in the retinal pigment epithelium. Comparing the lateral distribution of parameters of a tri-exponential model function in lifetime images of the fundus with the layered anatomical fundus structure, the shortest component (t1

  12. Toxicokinetics of the food-toxin IQ in human placental perfusion is not affected by ABCG2 or xenobiotic metabolism

    DEFF Research Database (Denmark)

    Immonen, E; Kummu, M; Petsalo, A

    2010-01-01

    Metabolizing enzymes and transporters affect toxicokinetics of foreign compounds (e.g. drugs and carcinogens) in human placenta. The heterocyclic amine, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) is a food-borne carcinogen being metabolically activated by cytochrome P450 (CYP) enzymes, especial...

  13. Liver Effects of Clinical Drugs Differentiated in Human Liver Slices

    Directory of Open Access Journals (Sweden)

    Alison E. M. Vickers

    2017-03-01

    Full Text Available Drugs with clinical adverse effects are compared in an ex vivo 3-dimensional multi-cellular human liver slice model. Functional markers of oxidative stress and mitochondrial function, glutathione GSH and ATP levels, were affected by acetaminophen (APAP, 1 mM, diclofenac (DCF, 1 mM and etomoxir (ETM, 100 μM. Drugs targeting mitochondria more than GSH were dantrolene (DTL, 10 μM and cyclosporin A (CSA, 10 μM, while GSH was affected more than ATP by methimazole (MMI, 500 μM, terbinafine (TBF, 100 μM, and carbamazepine (CBZ 100 μM. Oxidative stress genes were affected by TBF (18%, CBZ, APAP, and ETM (12%–11%, and mitochondrial genes were altered by CBZ, APAP, MMI, and ETM (8%–6%. Apoptosis genes were affected by DCF (14%, while apoptosis plus necrosis were altered by APAP and ETM (15%. Activation of oxidative stress, mitochondrial energy, heat shock, ER stress, apoptosis, necrosis, DNA damage, immune and inflammation genes ranked CSA (75%, ETM (66%, DCF, TBF, MMI (61%–60%, APAP, CBZ (57%–56%, and DTL (48%. Gene changes in fatty acid metabolism, cholestasis, immune and inflammation were affected by DTL (51%, CBZ and ETM (44%–43%, APAP and DCF (40%–38%, MMI, TBF and CSA (37%–35%. This model advances multiple dosing in a human ex vivo model, plus functional markers and gene profile markers of drug induced human liver side-effects.

  14. Drug Metabolizing Enzyme and Transporter Gene Variation, Nicotine Metabolism, Prospective Abstinence, and Cigarette Consumption.

    Directory of Open Access Journals (Sweden)

    Andrew W Bergen

    Full Text Available The Nicotine Metabolite Ratio (NMR, ratio of trans-3'-hydroxycotinine and cotinine, has previously been associated with CYP2A6 activity, response to smoking cessation treatments, and cigarette consumption. We searched for drug metabolizing enzyme and transporter (DMET gene variation associated with the NMR and prospective abstinence in 2,946 participants of laboratory studies of nicotine metabolism and of clinical trials of smoking cessation therapies. Stage I was a meta-analysis of the association of 507 common single nucleotide polymorphisms (SNPs at 173 DMET genes with the NMR in 449 participants of two laboratory studies. Nominally significant associations were identified in ten genes after adjustment for intragenic SNPs; CYP2A6 and two CYP2A6 SNPs attained experiment-wide significance adjusted for correlated SNPs (CYP2A6 PACT=4.1E-7, rs4803381 PACT=4.5E-5, rs1137115, PACT=1.2E-3. Stage II was mega-regression analyses of 10 DMET SNPs with pretreatment NMR and prospective abstinence in up to 2,497 participants from eight trials. rs4803381 and rs1137115 SNPs were associated with pretreatment NMR at genome-wide significance. In post-hoc analyses of CYP2A6 SNPs, we observed nominally significant association with: abstinence in one pharmacotherapy arm; cigarette consumption among all trial participants; and lung cancer in four case:control studies. CYP2A6 minor alleles were associated with reduced NMR, CPD, and lung cancer risk. We confirmed the major role that CYP2A6 plays in nicotine metabolism, and made novel findings with respect to genome-wide significance and associations with CPD, abstinence and lung cancer risk. Additional multivariate analyses with patient variables and genetic modeling will improve prediction of nicotine metabolism, disease risk and smoking cessation treatment prognosis.

  15. Natural products, an important resource for discovery of multitarget drugs and functional food for regulation of hepatic glucose metabolism.

    Science.gov (United States)

    Li, Jian; Yu, Haiyang; Wang, Sijian; Wang, Wei; Chen, Qian; Ma, Yanmin; Zhang, Yi; Wang, Tao

    2018-01-01

    Imbalanced hepatic glucose homeostasis is one of the critical pathologic events in the development of metabolic syndromes (MSs). Therefore, regulation of imbalanced hepatic glucose homeostasis is important in drug development for MS treatment. In this review, we discuss the major targets that regulate hepatic glucose homeostasis in human physiologic and pathophysiologic processes, involving hepatic glucose uptake, glycolysis and glycogen synthesis, and summarize their changes in MSs. Recent literature suggests the necessity of multitarget drugs in the management of MS disorder for regulation of imbalanced glucose homeostasis in both experimental models and MS patients. Here, we highlight the potential bioactive compounds from natural products with medicinal or health care values, and focus on polypharmacologic and multitarget natural products with effects on various signaling pathways in hepatic glucose metabolism. This review shows the advantage and feasibility of discovering multicompound-multitarget drugs from natural products, and providing a new perspective of ways on drug and functional food development for MSs.

  16. Cutaneous in vivo metabolism of topical lidocaine formulation in human skin

    DEFF Research Database (Denmark)

    Rolsted, K; Benfeldt, E; Kissmeyer, A-M

    2009-01-01

    Little is known about the metabolising capacity of the human skin in relation to topically applied drugs and formulations. We chose lidocaine as a model compound since the metabolic pathways are well known from studies concerning hepatic metabolism following systemic drug administration. However......, the enzymes involved are also expressed in the skin. Hence, the aim of the current study was to investigate the extent of the cutaneous in vivo metabolism of topically applied lidocaine in human volunteers. A dose of 5 mg/cm(2) of Xylocaine(R) (5% lidocaine) ointment was applied onto the buttock skin...... of the volunteers. After 2 h, residual formulation was removed, and two 4-mm punch biopsies were taken from each volunteer. The quantity of lidocaine extracted from the skin samples (epidermis + dermis) was 109 +/- 43 ng/mm(2) skin. One metabolite (monoethylglycine xylidide, MEGX) was detected in skin from 7...

  17. Molecular Networking As a Drug Discovery, Drug Metabolism, and Precision Medicine Strategy.

    Science.gov (United States)

    Quinn, Robert A; Nothias, Louis-Felix; Vining, Oliver; Meehan, Michael; Esquenazi, Eduardo; Dorrestein, Pieter C

    2017-02-01

    Molecular networking is a tandem mass spectrometry (MS/MS) data organizational approach that has been recently introduced in the drug discovery, metabolomics, and medical fields. The chemistry of molecules dictates how they will be fragmented by MS/MS in the gas phase and, therefore, two related molecules are likely to display similar fragment ion spectra. Molecular networking organizes the MS/MS data as a relational spectral network thereby mapping the chemistry that was detected in an MS/MS-based metabolomics experiment. Although the wider utility of molecular networking is just beginning to be recognized, in this review we highlight the principles behind molecular networking and its use for the discovery of therapeutic leads, monitoring drug metabolism, clinical diagnostics, and emerging applications in precision medicine. Copyright © 2016. Published by Elsevier Ltd.

  18. Regulation of Brain Glucose Metabolic Patterns by Protein Phosphorlyation and Drug Therapy

    Science.gov (United States)

    2007-03-30

    Tymoczko et al. 2002). Both cardiac muscle and brain contain the necessary enzymes to metabolize either glucose or ketone bodies . The enzymes... metabolic phenotype of astrocytes and neurons in vitro; and to determine whether antipsychotic drug administration affects glucose metabolites in...Cortical Astrocytes and Neurons 20 Abstract 21 v Introduction ~ 22 Results 24 Enriched Astrocyte and Neuronal Cultures Display Unique Metabolic

  19. Peroxisomes, lipid metabolism, and human disease

    NARCIS (Netherlands)

    Wanders, R. J.

    2000-01-01

    In the past few years, much has been learned about the metabolic functions of peroxisomes. These studies have shown that peroxisomes play a major role in lipid metabolism, including fatty acid beta-oxidation, etherphospholipid biosynthesis, and phytanic acid alpha-oxidation. This article describes

  20. Reduction in hepatic drug metabolizing CYP3A4 activities caused by P450 oxidoreductase mutations identified in patients with disordered steroid metabolism

    International Nuclear Information System (INIS)

    Flueck, Christa E.; Mullis, Primus E.; Pandey, Amit V.

    2010-01-01

    Research highlights: → Cytochrome P450 3A4 (CYP3A4), metabolizes 50% of drugs in clinical use and requires NADPH-P450 reductase (POR). → Mutations in human POR cause congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. → We are reporting that mutations in POR may reduce CYP3A4 activity. → POR mutants Y181D, A457H, Y459H, V492E and R616X lost 99%, while A287P, C569Y and V608F lost 60-85% CYP3A4 activity. → Reduction of CYP3A4 activity may cause increased risk of drug toxicities/adverse drug reactions in patients with POR mutations. -- Abstract: Cytochrome P450 3A4 (CYP3A4), the major P450 present in human liver metabolizes approximately half the drugs in clinical use and requires electrons supplied from NADPH through NADPH-P450 reductase (POR, CPR). Mutations in human POR cause a rare form of congenital adrenal hyperplasia from diminished activities of steroid metabolizing P450s. In this study we examined the effect of mutations in POR on CYP3A4 activity. We used purified preparations of wild type and mutant human POR and in vitro reconstitution with purified CYP3A4 to perform kinetic studies. We are reporting that mutations in POR identified in patients with disordered steroidogenesis/Antley-Bixler syndrome (ABS) may reduce CYP3A4 activity, potentially affecting drug metabolism in individuals carrying mutant POR alleles. POR mutants Y181D, A457H, Y459H, V492E and R616X had more than 99% loss of CYP3A4 activity, while POR mutations A287P, C569Y and V608F lost 60-85% activity. Loss of CYP3A4 activity may result in increased risk of drug toxicities and adverse drug reactions in patients with POR mutations.

  1. Metabolic and Endocrine Side Effects of Atypical Antipsychotic Drugs in Children and Adolescents

    Directory of Open Access Journals (Sweden)

    Aysegul Tahiroglu

    2011-03-01

    Full Text Available omorbid psychiatric disorders, frequent hospitalization, multiple outpatient treatment, prior history of hypertension, obesity and lipid dysregulation are associated with higher risk of metabolic syndrome in children. Side effects of antipsychotic drugs and their management have recently become a major subject of research due to enhanced antipsychotic drug usage in child and adolescents. Prevention strategies are usually preferred to secondary or tertiary strategies in the management of metabolic syndrome associated with antipsychotic drugs. Clinicians should present multidisciplinary approach to endocrine and metabolic side effects due to antipsychotic use in pediatric patient groups and avoid multiple drug use in such patients. In this paper, we briefly reviewed metabolic side effects of second generation antipsychotic drugs in child and adolescent population, possible mechanisms of susceptibility to metabolic syndrome and pharmacological and non pharmacological treatment approach to prevention of weight gain.

  2. The use of cultured hepatocytes to investigate the metabolism of drugs and mechanisms of drug hepatotoxicity.

    Science.gov (United States)

    Gómez-Lechón, M J; Ponsoda, X; Bort, R; Castell, J V

    2001-01-01

    Hepatotoxins can be classified as intrinsic when they exert their effects on all individuals in a dose-dependent manner, and as idiosyncratic when their effects are the consequence of an abnormal metabolism of the drug by susceptible individuals (metabolic idiosyncrasy) or of an immune-mediated injury to hepatocytes (allergic hepatitis). Some xenobiotics are electrophilic, and others are biotransformed by the liver into highly reactive metabolites that are usually more toxic than the parent compound. This activation process is the key to many hepatotoxic phenomena. Mitochondria are a frequent target of hepatotoxic drugs, and the alteration of their function has immediate effects on the energy balance of cells (depletion of ATP). Lipid peroxidation, oxidative stress, alteration of Ca(2+) homeostasis, and covalent binding to cell macromolecules are the molecular mechanisms that are frequently involved in the toxicity of xenobiotics. Against these potential hazards, cells have their own defence mechanisms (for example, glutathione, DNA repair, suicide inactivation). Ultimately, toxicity is the balance between bioactivation and detoxification, which determines whether a reactive metabolite elicits a toxic effect. The ultimate goal of in vitro experiments is to generate the type of scientific information needed to identify compounds that are potentially toxic to man. For this purpose, both the design of the experiments and the interpretation of the results are critical.

  3. The fibrate drug gemfibrozil disrupts lipoprotein metabolism in rainbow trout

    International Nuclear Information System (INIS)

    Prindiville, John S.; Mennigen, Jan A.; Zamora, Jake M.; Moon, Thomas W.; Weber, Jean-Michel

    2011-01-01

    Gemfibrozil (GEM) is a fibrate drug consistently found in effluents from sewage treatment plants. This study characterizes the pharmacological effects of GEM on the plasma lipoproteins of rainbow trout (Oncorhynchus mykiss). Our goals were to quantify the impact of the drug on: 1) lipid constituents of lipoproteins (phospholipids (PL), triacylglycerol (TAG), and cholesterol), 2) lipoprotein classes (high, low and very low density lipoproteins), and 3) fatty acid composition of lipoproteins. Potential mechanisms of GEM action were investigated by measuring lipoprotein lipase activity (LPL) and the hepatic gene expression of LPL and of the peroxisome proliferator-activated receptor (PPAR) α, β, and γ isoforms. GEM treatment resulted in decreased plasma lipoprotein levels (- 29%) and a reduced size of all lipoprotein classes (lower PL:TAG ratios). However, the increase in HDL-cholesterol elicited by GEM in humans failed to be observed in trout. Therefore, HDL-cholesterol cannot be used to assess the impact of the drug on fish. GEM also modified lipoprotein composition by reducing the abundance of long-chain n-3 fatty acids, thereby potentially reducing the nutritional quality of exposed fish. The relative gene expression of LPL was increased, but the activity of the enzyme was not, and we found no evidence for the activation of PPAR pathways. The depressing effects of GEM on fish lipoproteins demonstrated here may be a concern in view of the widespread presence of fibrates in aquatic environments. Work is needed to test whether exposure to environmental concentrations of these drugs jeopardizes the capacity of fish for reproduction, temperature acclimation or migratory behaviors.

  4. Carboxylesterases in lipid metabolism: from mouse to human

    Directory of Open Access Journals (Sweden)

    Jihong Lian

    2017-07-01

    Full Text Available ABSTRACT Mammalian carboxylesterases hydrolyze a wide range of xenobiotic and endogenous compounds, including lipid esters. Physiological functions of carboxylesterases in lipid metabolism and energy homeostasis in vivo have been demonstrated by genetic manipulations and chemical inhibition in mice, and in vitro through (overexpression, knockdown of expression, and chemical inhibition in a variety of cells. Recent research advances have revealed the relevance of carboxylesterases to metabolic diseases such as obesity and fatty liver disease, suggesting these enzymes might be potential targets for treatment of metabolic disorders. In order to translate pre-clinical studies in cellular and mouse models to humans, differences and similarities of carboxylesterases between mice and human need to be elucidated. This review presents and discusses the research progress in structure and function of mouse and human carboxylesterases, and the role of these enzymes in lipid metabolism and metabolic disorders.

  5. Schisandra chinensis regulates drug metabolizing enzymes and drug transporters via activation of Nrf2-mediated signaling pathway

    Directory of Open Access Journals (Sweden)

    He JL

    2014-12-01

    Full Text Available Jin-Lian He,1 Zhi-Wei Zhou,2,3 Juan-Juan Yin,2 Chang-Qiang He,1 Shu-Feng Zhou,2,3 Yang Yu1 1College of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China; 2Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; 3Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guiyang Medical University, Guiyang, Guizhou, People’s Republic of China Abstract: Drug metabolizing enzymes (DMEs and drug transporters are regulated via epigenetic, transcriptional, posttranscriptional, and translational and posttranslational modifications. Phase I and II DMEs and drug transporters play an important role in the disposition and detoxification of a large number of endogenous and exogenous compounds. The nuclear factor (erythroid-derived 2-like 2 (Nrf2 is a critical regulator of a variety of important cytoprotective genes that are involved in disposition and detoxification of xenobiotics. Schisandra chinensis (SC is a commonly used traditional Chinese herbal medicine that has been primarily used to protect the liver because of its potent antioxidative and anti-inflammatory activities. SC can modulate some DMEs and drug transporters, but the underlying mechanisms are unclear. In this study, we aimed to explore the role of Nrf2 in the regulatory effect of SC extract (SCE on selected DMEs and drug transporters in human hepatocellular liver carcinoma cell line (HepG2 cells. The results showed that SCE, schisandrin A, and schisandrin B significantly increased the expression of NAD(PH: Nicotinamide Adenine Dinucleotide Phosphate-oxidase or:quinone oxidoreductase 1, heme oxygenase-1, glutamate–cysteine ligase, and glutathione S-transferase A4 at both transcriptional and posttranscriptional levels. Incubation of HepG2 cells with SCE resulted in a significant

  6. Microbiome-mediated bile acid modification: Role in intestinal drug absorption and metabolism.

    Science.gov (United States)

    Enright, Elaine F; Griffin, Brendan T; Gahan, Cormac G M; Joyce, Susan A

    2018-04-13

    Once regarded obscure and underappreciated, the gut microbiota (the microbial communities colonizing the gastrointestinal tract) is gaining recognition as an influencer of many aspects of human health. Also increasingly apparent is the breadth of interindividual variation in these co-evolved microbial-gut associations, presenting novel quests to explore implications for disease and therapeutic response. In this respect, the unearthing of the drug-metabolizing capacity of the microbiota has provided impetus for the integration of microbiological and pharmacological research. This review considers a potential mechanism, 'microbial bile acid metabolism', by which the intricate interplay between the host and gut bacteria may influence drug pharmacokinetics. Bile salts traditionally regarded as biological surfactants, synthesized by the host and biotransformed by gut bacteria, are now also recognized as signalling molecules that affect diverse physiological processes. Accumulating data indicate that bile salts are not equivalent with respect to their physicochemical properties, micellar solubilization capacities for poorly water-soluble drugs, crystallization inhibition tendencies nor potencies for bile acid receptor activation. Herein, the origin, physicochemical properties, physiological functions, plasticity and pharmaceutical significance of the human bile acid pool are discussed. Microbial dependant differences in the composition of the human bile acid pool, simulated intestinal media and commonly used preclinical species is highlighted to better understand in vivo performance predictiveness. While the precise impact of an altered gut microbiome, and consequently bile acid pool, in the biopharmaceutical setting remains largely elusive, the objective of this article is to aid knowledge acquisition through a detailed review of the literature. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Drug metabolizing enzyme systems and their relationship to toxic mechanisms

    International Nuclear Information System (INIS)

    Boyd, M.R.; Ravindranath, V.; Burka, L.T.

    1983-01-01

    The metabolism and toxicity of 3-methylfuran (3-MF) are described. The major product of metabolic activation of 3-MF appears to be disemicarbazones. Cursory description of toxic effects of 3-MF on lung and kidneys are provided. 18 refs

  8. Genetic variation in eleven phase I drug metabolism genes in an ethnically diverse population.

    Science.gov (United States)

    Solus, Joseph F; Arietta, Brenda J; Harris, James R; Sexton, David P; Steward, John Q; McMunn, Chara; Ihrie, Patrick; Mehall, Janelle M; Edwards, Todd L; Dawson, Elliott P

    2004-10-01

    The extent of genetic variation found in drug metabolism genes and its contribution to interindividual variation in response to medication remains incompletely understood. To better determine the identity and frequency of variation in 11 phase I drug metabolism genes, the exons and flanking intronic regions of the cytochrome P450 (CYP) isoenzyme genes CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5 were amplified from genomic DNA and sequenced. A total of 60 kb of bi-directional sequence was generated from each of 93 human DNAs, which included Caucasian, African-American and Asian samples. There were 388 different polymorphisms identified. These included 269 non-coding, 45 synonymous and 74 non-synonymous polymorphisms. Of these, 54% were novel and included 176 non-coding, 14 synonymous and 21 non-synonymous polymorphisms. Of the novel variants observed, 85 were represented by single occurrences of the minor allele in the sample set. Much of the variation observed was from low-frequency alleles. Comparatively, these genes are variation-rich. Calculations measuring genetic diversity revealed that while the values for the individual genes are widely variable, the overall nucleotide diversity of 7.7 x 10(-4) and polymorphism parameter of 11.5 x 10(-4) are higher than those previously reported for other gene sets. Several independent measurements indicate that these genes are under selective pressure, particularly for polymorphisms corresponding to non-synonymous amino acid changes. There is relatively little difference in measurements of diversity among the ethnic groups, but there are large differences among the genes and gene subfamilies themselves. Of the three CYP subfamilies involved in phase I drug metabolism (1, 2, and 3), subfamily 2 displays the highest levels of genetic diversity.

  9. METABOLIC MEDICATIONS FOR THE REHABILITATION OF CHILDREN BORN TO DRUG ADDICTED WOMEN

    Directory of Open Access Journals (Sweden)

    A.A. Dzhumagaziev

    2007-01-01

    Full Text Available The authors presented the study results of the physical and neuro psychic growth of children, who were born to drug addicted women. they studied the active state of the dehydrogenase peripheral blood lymphocytes, reflecting the metabolic disorder at the tissue level and body level in general, as well as the ways to correct them with metabolic therapy assisted by glycine and biotredin. They also analyzed the results of the complex therapy and rehabilitation of the children, who were born to drug addicted women.Key words: drug embryopathy, metabolic therapy, children, rehabilitation.

  10. Metabolic heat production by human and animal populations in cities

    Science.gov (United States)

    Stewart, Iain D.; Kennedy, Chris A.

    2017-07-01

    Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to <1% of anthropogenic heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai—the world's most densely populated megacity—at 6.5 W m-2, surpassing heat production by electricity use in buildings (5.8 W m-2) and fuel combustion in vehicles (3.9 W m-2). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

  11. Metabolic syndrome in human immunodeficiency virus positive patients

    Directory of Open Access Journals (Sweden)

    Sarita Bajaj

    2013-01-01

    Full Text Available Aims and Objectives : To assess the prevalence of metabolic syndrome (MetS in human immunodeficiency virus (HIV positive patients. Prevalence of MetS was compared in patients who were not on highly active antiretroviral therapy (HAART to patients who were on HAART. Materials and Methods: Seventy HIV positive cases were studied. Pregnant and lactating women, patients on drugs other than HAART known to cause metabolic abnormalities and those having diabetes or hypertension were excluded. Cases were evaluated for MetS by using National Cholesterol Education Program Adult Treatment Panel-III. Results: 47 cases were on HAART and 23 cases were not on HAART. Fasting Blood Glucose ≥100 mg/dl was present in 28.6% cases, out of whom 27.7% were on HAART and 30.4% were not on HAART (P = 0.8089. 12.9% cases had BP ≥130/≥85 mm Hg, out of whom 14.9% were on HAART and 8.7% were not on HAART (P = 0.4666. 42.9% cases had TG ≥150 mg/dl, out of whom 44.7% were on HAART and 39.1% were not on HAART (P = 0.6894. HDL cholesterol was low (males <40 mg/dl, females <50 mg/dl in 50% cases, out of whom 55.3% were on HAART and 39.1% were not on HAART (P = 0.2035. Conclusions: Prevalence of MetS was 20%. Majority of patients had only one component of MetS (32.9%. Low HDL was present in 50%, followed by raised triglycerides in 42.9%. Waist circumference was not increased in any of the patients. There was no statistically significant difference between those on HAART and those not on HAART in distribution of risk factors and individual components of MetS.

  12. Xenobiotic-metabolizing enzymes in plants and their role in uptake and biotransformation of veterinary drugs in the environment.

    Science.gov (United States)

    Bártíková, Hana; Skálová, Lenka; Stuchlíková, Lucie; Vokřál, Ivan; Vaněk, Tomáš; Podlipná, Radka

    2015-08-01

    Many various xenobiotics permanently enter plants and represent potential danger for their organism. For that reason, plants have evolved extremely sophisticated detoxification systems including a battery of xenobiotic-metabolizing enzymes. Some of them are similar to those in humans and animals, but there are several plant-specific ones. This review briefly introduces xenobiotic-metabolizing enzymes in plants and summarizes present information about their action toward veterinary drugs. Veterinary drugs are used worldwide to treat diseases and protect animal health. However, veterinary drugs are also unwantedly introduced into environment mostly via animal excrements, they persist in the environment for a long time and may impact on the non-target organisms. Plants are able to uptake, transform the veterinary drugs to non- or less-toxic compounds and store them in the vacuoles and cell walls. This ability may protect not only plant themselves but also other organisms, predominantly invertebrates and wild herbivores. The aim of this review is to emphasize the importance of plants in detoxification of veterinary drugs in the environment. The results of studies, which dealt with transport and biotransformation of veterinary drugs in plants, are summarized and evaluated. In conclusion, the risks and consequences of veterinary drugs in the environment and the possibilities of phytoremediation technologies are considered and future perspectives are outlined.

  13. Functional interrogation of Plasmodium genus metabolism identifies species- and stage-specific differences in nutrient essentiality and drug targeting.

    Directory of Open Access Journals (Sweden)

    Alyaa M Abdel-Haleem

    2018-01-01

    Full Text Available Several antimalarial drugs exist, but differences between life cycle stages among malaria species pose challenges for developing more effective therapies. To understand the diversity among stages and species, we reconstructed genome-scale metabolic models (GeMMs of metabolism for five life cycle stages and five species of Plasmodium spanning the blood, transmission, and mosquito stages. The stage-specific models of Plasmodium falciparum uncovered stage-dependent changes in central carbon metabolism and predicted potential targets that could affect several life cycle stages. The species-specific models further highlight differences between experimental animal models and the human-infecting species. Comparisons between human- and rodent-infecting species revealed differences in thiamine (vitamin B1, choline, and pantothenate (vitamin B5 metabolism. Thus, we show that genome-scale analysis of multiple stages and species of Plasmodium can prioritize potential drug targets that could be both anti-malarials and transmission blocking agents, in addition to guiding translation from non-human experimental disease models.

  14. In Vitro Disease Model of Microgravity Conditioning on Human Energy Metabolism

    Science.gov (United States)

    Snyder, Jessica; Culbertson, C.; Zhang, Ye; Emami, K.; Wu, H.; Sun, Wei

    2010-01-01

    NASA and its partners are committed to introducing appropriate new technology to enable learning and living safely beyond the Earth for extended periods of time in a sustainable and possibly indefinite manner. In the responsible acquisition of that goal, life sciences is tasked to tune and advance current medical technology to prepare for human health and wellness in the space environment. The space environment affects the condition and function of biological systems from organ level function to shape of individual organelles. The objective of this paper is to study the effect of microgravity on kinetics of drug metabolism. This fundamental characterization is meaningful to (1) scientific understanding of the response of biology to microgravity and (2) clinical dosing requirements and pharmacological thresholds during long term manned space exploration. Metabolism kinetics of the anti-nausea drug promethazine (PMZ) were determined by an in vitro ground model of 3-dimensional aggregates of human hepatocytes conditioned to weightlessness using a rotating wall bioreactor. The authors observed up-regulated PMZ conversion in model microgravity conditions and attribute this to effect to model microgravity conditioning acting on metabolic mechanisms of the cells. Further work is necessary to determine which particular cellular mechanisms are governing the experimental observations, but the authors conclude kinetics of drug metabolism are responsive to gravitational fields and further study of this sensitivity would improve dosing of pharmaceuticals to persons exposed to a microgravity environment.

  15. The Metabolism of Separase Inhibitor Sepin-1 in Human, Mouse, and Rat Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Feng Li

    2018-05-01

    Full Text Available Separase, a known oncogene, is widely overexpressed in numerous human tumors of breast, bone, brain, blood, and prostate. Separase is an emerging target for cancer therapy, and separase enzymatic inhibitors such as sepin-1 are currently being developed to treat separase-overexpressed tumors. Drug metabolism plays a critical role in the efficacy and safety of drug development, as well as possible drug–drug interactions. In this study, we investigated the in vitro metabolism of sepin-1 in human, mouse, and rat liver microsomes (RLM using metabolomic approaches. In human liver microsomes (HLM, we identified seven metabolites including one cysteine–sepin-1 adduct and one glutathione–sepin-1 adduct. All the sepin-1 metabolites in HLM were also found in both mouse and RLM. Using recombinant CYP450 isoenzymes, we demonstrated that multiple enzymes contributed to the metabolism of sepin-1, including CYP2D6 and CYP3A4 as the major metabolizing enzymes. Inhibitory effects of sepin-1 on seven major CYP450s were also evaluated using the corresponding substrates recommended by the US Food and Drug Administration. Our studies indicated that sepin-1 moderately inhibits CYP1A2, CYP2C19, and CYP3A4 with IC50 < 10 μM but weakly inhibits CYP2B6, CYP2C8/9, and CYP2D6 with IC50 > 10 μM. This information can be used to optimize the structures of sepin-1 for more suitable pharmacological properties and to predict the possible sepin-1 interactions with other chemotherapeutic drugs.

  16. An ex Vivo Model for Evaluating Blood-Brain Barrier Permeability, Efflux, and Drug Metabolism

    DEFF Research Database (Denmark)

    Hellman, Karin; Aadal Nielsen, Peter; Ek, Fredrik

    2016-01-01

    , risperidone, citalopram, fluoxetine, and haloperidol were studied, and one preselected metabolite for each drug was analyzed, identified, and quantified. Metabolite identification studies of clozapine and midazolam showed that the locust brain was highly metabolically active, and 18 and 14 metabolites...

  17. Radiosensitivity of drug-resistant human tumour xenografts

    International Nuclear Information System (INIS)

    Mattern, J.; Bak, M. Jr.; Volm, M.; Hoever, K.H.

    1989-01-01

    The radiosensitivity of three drug-resistant sublines of a human epidermoid lung carcinoma growing as xenografts in nude mice was investigated. Drug resistance to vincristine, actinomycin D and cisplatin was developed in vivo by repeated drug treatment. It was found that all three drug-resistant tumour lines were not cross-resistant to irradiation. (orig.) [de

  18. Antilipolytic drug boosts glucose metabolism in prostate cancer

    International Nuclear Information System (INIS)

    Andersen, Kim Francis; Divilov, Vadim; Koziorowski, Jacek; Pillarsetty, NagaVaraKishore; Lewis, Jason S.

    2013-01-01

    Introduction: The antilipolytic drug Acipimox reduces free fatty acid (FFA) levels in the blood stream. We examined the effect of reduced FFAs on glucose metabolism in androgen-dependent (CWR22Rv1) and androgen-independent (PC3) prostate cancer (PCa) xenografts. Methods: Subcutaneous tumors were produced in nude mice by injection of PC3 and CWR22Rv1 PCa cells. The mice were divided into two groups (Acipimox vs. controls). Acipimox (50 mg/kg) was administered by oral gavage 1 h before injection of tracers. 1 h after i.v. co-injection of 8.2 MBq (222 ± 6.0 μCi) 18 F-FDG and ∼ 0.0037 MBq (0.1 μCi) 14 C-acetate, 18 F-FDG imaging was performed using a small-animal PET scanner. Counting rates in reconstructed images were converted to activity concentrations. Quantification was obtained by region-of-interest analysis using dedicated software. The mice were euthanized, and blood samples and organs were harvested. 18 F radioactivity was measured in a calibrated γ-counter using a dynamic counting window and decay correction. 14 C radioactivity was determined by liquid scintillation counting using external standard quench corrections. Counts were converted into activity, and percentage of the injected dose per gram (%ID/g) tissue was calculated. Results: FDG biodistribution data in mice with PC3 xenografts demonstrated doubled average %ID/g tumor tissue after administration of Acipimox compared to controls (7.21 ± 1.93 vs. 3.59 ± 1.35, P = 0.02). Tumor-to-organ ratios were generally higher in mice treated with Acipimox. This was supported by PET imaging data, both semi-quantitatively (mean tumor FDG uptake) and visually (tumor-to-background ratios). In mice with CWR22Rv1 xenografts there was no effect of Acipimox on FDG uptake, either in biodistribution or PET imaging. 14 C-acetate uptake was unaffected in PC3 and CWR22Rv1 xenografts. Conclusions: In mice with PC3 PCa xenografts, acute administration of Acipimox increases tumor uptake of 18 F-FDG with general

  19. IL-6 selectively stimulates fat metabolism in human skeletal muscle

    DEFF Research Database (Denmark)

    Wolsk, Emil; Mygind, Helene; Grøndahl, Thomas S

    2010-01-01

    and glucose metabolism and signaling of both adipose tissue and skeletal muscle. Eight healthy postabsorptive males were infused with either rhIL-6 or saline for 4 h, eliciting IL-6 levels of ~40 and ~1 pg/ml, respectively. Systemic, skeletal muscle, and adipose tissue fat and glucose metabolism was assessed......Interleukin (IL)-6 is chronically elevated in type 2 diabetes but also during exercise. However, the exact metabolic role, and hence the physiological significance, has not been elucidated. The objective of this study was to investigate the in vivo effect of recombinant human (rh) IL-6 on human fat...... before, during, and 2 h after cessation of the infusion. Glucose metabolism was unaffected by rhIL-6. In contrast, rhIL-6 increased systemic fatty acid oxidation approximately twofold after 60 min, and it remained elevated even 2 h after the infusion. The increase in oxidation was followed by an increase...

  20. IL-6 selectively stimulates fat metabolism in human skeletal muscle

    DEFF Research Database (Denmark)

    Wolsk, Emil; Mygind, Helene; Grøndahl, Thomas S

    2010-01-01

    and glucose metabolism and signaling of both adipose tissue and skeletal muscle. Eight healthy postabsorptive males were infused with either rhIL-6 or saline for 4 h, eliciting IL-6 levels of ∼40 and ∼1 pg/ml, respectively. Systemic, skeletal muscle, and adipose tissue fat and glucose metabolism was assessed......Interleukin (IL)-6 is chronically elevated in type 2 diabetes but also during exercise. However, the exact metabolic role, and hence the physiological significance, has not been elucidated. The objective of this study was to investigate the in vivo effect of recombinant human (rh) IL-6 on human fat...... before, during, and 2 h after cessation of the infusion. Glucose metabolism was unaffected by rhIL-6. In contrast, rhIL-6 increased systemic fatty acid oxidation approximately twofold after 60 min, and it remained elevated even 2 h after the infusion. The increase in oxidation was followed by an increase...

  1. New paradigms for metabolic modeling of human cells

    DEFF Research Database (Denmark)

    Mardinoglu, Adil; Nielsen, Jens

    2015-01-01

    review recent work on reconstruction of GEMs for human cell/tissue types and cancer, and the use of GEMs for identification of metabolic changes occurring in response to disease development. We further discuss how GEMs can be used for the development of efficient therapeutic strategies. Finally......, challenges in integration of cell/tissue models for simulation of whole body functions as well as integration of GEMs with other biological networks for generating complete cell/tissue models are presented.......Abnormalities in cellular functions are associated with the progression of human diseases, often resulting in metabolic reprogramming. GEnome-scale metabolic Models (GEMs) have enabled studying global metabolic reprogramming in connection with disease development in a systematic manner. Here we...

  2. Astrocyte Senescence and Metabolic Changes in Response to HIV Antiretroviral Therapy Drugs

    Directory of Open Access Journals (Sweden)

    Justin Cohen

    2017-08-01

    Full Text Available With the advent of highly active antiretroviral therapy (HAART survival rates among patients infected by HIV have increased. However, even though survival has increased HIV-associated neurocognitive disorders (HAND still persist, suggesting that HAART-drugs may play a role in the neurocognitive impairment observed in HIV-infected patients. Given previous data demonstrating that astrocyte senescence plays a role in neurocognitive disorders such as Alzheimer’s disease (AD, we examined the role of HAART on markers of senescence in primary cultures of human astrocytes (HAs. Our results indicate HAART treatment induces cell cycle arrest, senescence-associated beta-galactosidase, and the cell cycle inhibitor p21. Highly active antiretroviral therapy treatment is also associated with the induction of reactive oxygen species and upregulation of mitochondrial oxygen consumption. These changes in mitochondria correlate with increased glycolysis in HAART drug treated astrocytes. Taken together these results indicate that HAART drugs induce the senescence program in HAs, which is associated with oxidative and metabolic changes that could play a role in the development of HAND.

  3. Xenobiotic metabolism in human skin and 3D human skin reconstructs: A review

    NARCIS (Netherlands)

    Gibbs, S.; Sandt, J.J.M. van de; Merk, H.F.; Lockley, D.J.; Pendlington, R.U.; Pease, C.K.

    2007-01-01

    In this review, we discuss and compare studies of xenobiotic metabolism in both human skin and 3D human skin reconstructs. In comparison to the liver, the skin is a less studied organ in terms of characterising metabolic capability. While the skin forms the major protective barrier to environmental

  4. 78 FR 29755 - Human Immunodeficiency Virus Patient-Focused Drug Development and Human Immunodeficiency Virus...

    Science.gov (United States)

    2013-05-21

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0473] Human Immunodeficiency Virus Patient-Focused Drug Development and Human Immunodeficiency Virus Cure... an opportunity for public comment on human immunodeficiency virus (HIV) Patient-Focused Drug...

  5. 78 FR 46969 - Human Immunodeficiency Virus Patient-Focused Drug Development and Human Immunodeficiency Virus...

    Science.gov (United States)

    2013-08-02

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0473] Human Immunodeficiency Virus Patient-Focused Drug Development and Human Immunodeficiency Virus Cure... for the notice of public meeting entitled ``Human Immunodeficiency Virus (HIV) Patient-Focused Drug...

  6. Polymorphisms in drug-metabolizing enzymes: What is their clinical relevance and why do they exist?

    Energy Technology Data Exchange (ETDEWEB)

    Nebert, D.W. [Univ. of Cincinnati Medical Center, OH (United States)

    1997-02-01

    The beautiful report by Sachse in this issue of the journal represents the culmination of 2 decades of increasingly exciting work on the {open_quotes}debrisoquine oxidation polymorphism,{close_quotes} one of dozens of pharmacogenetic or ecogenetic polymorphisms that have been shown to have an important impact on innumerable clinical diseases. Pharmacogenetics is the study of the hereditary basis of the differences in responses to drugs. Ecogenetics is the broader field of interindividual differences in response to all environmental chemical and physical agents (e.g., heavy metals, insecticides, compounds formed during combustion, and UV radiation). It is now clear that each of us has his or her own {open_quotes}individual fingerprint{close_quotes} of unique alleles encoding the so-called drug-metabolizing enzymes (DMEs) and the receptors that regulate these enzymes. In this invited editorial, I first introduce the current thinking in the field of DME (and DME-receptor) research and how DMEs have evolved from animal-plant interactions. I then describe the debrisoquine oxidation polymorphism, as well as two other relevant DME polymorphisms; show the relationship between these polymorphisms and human disease; provide examples of synergistic effects caused by the combination of two DME polymorphisms; and discuss the ethical considerations of such research. Last, I speculate on why these allelic frequencies of the DME genes might exist in human populations in the first place. 35 refs.

  7. Metabolic state alters economic decision making under risk in humans.

    Directory of Open Access Journals (Sweden)

    Mkael Symmonds

    2010-06-01

    Full Text Available Animals' attitudes to risk are profoundly influenced by metabolic state (hunger and baseline energy stores. Specifically, animals often express a preference for risky (more variable food sources when below a metabolic reference point (hungry, and safe (less variable food sources when sated. Circulating hormones report the status of energy reserves and acute nutrient intake to widespread targets in the central nervous system that regulate feeding behaviour, including brain regions strongly implicated in risk and reward based decision-making in humans. Despite this, physiological influences per se have not been considered previously to influence economic decisions in humans. We hypothesised that baseline metabolic reserves and alterations in metabolic state would systematically modulate decision-making and financial risk-taking in humans.We used a controlled feeding manipulation and assayed decision-making preferences across different metabolic states following a meal. To elicit risk-preference, we presented a sequence of 200 paired lotteries, subjects' task being to select their preferred option from each pair. We also measured prandial suppression of circulating acyl-ghrelin (a centrally-acting orexigenic hormone signalling acute nutrient intake, and circulating leptin levels (providing an assay of energy reserves. We show both immediate and delayed effects on risky decision-making following a meal, and that these changes correlate with an individual's baseline leptin and changes in acyl-ghrelin levels respectively.We show that human risk preferences are exquisitely sensitive to current metabolic state, in a direction consistent with ecological models of feeding behaviour but not predicted by normative economic theory. These substantive effects of state changes on economic decisions perhaps reflect shared evolutionarily conserved neurobiological mechanisms. We suggest that this sensitivity in human risk-preference to current metabolic state has

  8. The effects of estrus cycle on drug metabolism in the rat.

    Science.gov (United States)

    Brandstetter, Y; Kaplanski, J; Leibson, V; Ben-Zvi, Z

    1986-01-01

    The effect of the female rat estral cycle on microsomal drug metabolism in-vivo and in-vitro has been studied. Two microsomal enzymes, aminopyrine-N-demethylase and aniline hydroxylase showed a greater specific activity (p less than 0.01) in the diestrus phase of the estral cycle while the oxidative enzyme aryl hydrocarbon hydroxylase and the conjugative enzyme, glucuronyl transferase, were not affected. In vivo studies which included theophylline and antipyrine metabolism, and hexobarbital sleeping times showed no difference between the different phases of the estral cycle. Conflicting evidence about the effect of steroid sex hormones on hepatic drug metabolism is discussed.

  9. Modeling of pharmacokinetics of cocaine in human reveals the feasibility for development of enzyme therapies for drugs of abuse.

    Directory of Open Access Journals (Sweden)

    Fang Zheng

    Full Text Available A promising strategy for drug abuse treatment is to accelerate the drug metabolism by administration of a drug-metabolizing enzyme. The question is how effectively an enzyme can actually prevent the drug from entering brain and producing physiological effects. In the present study, we have developed a pharmacokinetic model through a combined use of in vitro kinetic parameters and positron emission tomography data in human to examine the effects of a cocaine-metabolizing enzyme in plasma on the time course of cocaine in plasma and brain of human. Without an exogenous enzyme, cocaine half-lives in both brain and plasma are almost linearly dependent on the initial cocaine concentration in plasma. The threshold concentration of cocaine in brain required to produce physiological effects has been estimated to be 0.22±0.07 µM, and the threshold area under the cocaine concentration versus time curve (AUC value in brain (denoted by AUC2(∞ required to produce physiological effects has been estimated to be 7.9±2.7 µM·min. It has been demonstrated that administration of a cocaine hydrolase/esterase (CocH/CocE can considerably decrease the cocaine half-lives in both brain and plasma, the peak cocaine concentration in brain, and the AUC2(∞. The estimated maximum cocaine plasma concentration which a given concentration of drug-metabolizing enzyme can effectively prevent from entering brain and producing physiological effects can be used to guide future preclinical/clinical studies on cocaine-metabolizing enzymes. Understanding of drug-metabolizing enzymes is key to the science of pharmacokinetics. The general insights into the effects of a drug-metabolizing enzyme on drug kinetics in human should be valuable also in future development of enzyme therapies for other drugs of abuse.

  10. Modeling of pharmacokinetics of cocaine in human reveals the feasibility for development of enzyme therapies for drugs of abuse.

    Science.gov (United States)

    Zheng, Fang; Zhan, Chang-Guo

    2012-01-01

    A promising strategy for drug abuse treatment is to accelerate the drug metabolism by administration of a drug-metabolizing enzyme. The question is how effectively an enzyme can actually prevent the drug from entering brain and producing physiological effects. In the present study, we have developed a pharmacokinetic model through a combined use of in vitro kinetic parameters and positron emission tomography data in human to examine the effects of a cocaine-metabolizing enzyme in plasma on the time course of cocaine in plasma and brain of human. Without an exogenous enzyme, cocaine half-lives in both brain and plasma are almost linearly dependent on the initial cocaine concentration in plasma. The threshold concentration of cocaine in brain required to produce physiological effects has been estimated to be 0.22±0.07 µM, and the threshold area under the cocaine concentration versus time curve (AUC) value in brain (denoted by AUC2(∞)) required to produce physiological effects has been estimated to be 7.9±2.7 µM·min. It has been demonstrated that administration of a cocaine hydrolase/esterase (CocH/CocE) can considerably decrease the cocaine half-lives in both brain and plasma, the peak cocaine concentration in brain, and the AUC2(∞). The estimated maximum cocaine plasma concentration which a given concentration of drug-metabolizing enzyme can effectively prevent from entering brain and producing physiological effects can be used to guide future preclinical/clinical studies on cocaine-metabolizing enzymes. Understanding of drug-metabolizing enzymes is key to the science of pharmacokinetics. The general insights into the effects of a drug-metabolizing enzyme on drug kinetics in human should be valuable also in future development of enzyme therapies for other drugs of abuse.

  11. Individualization of treatments with drugs metabolized by CES1: combining genetics and metabolomics

    DEFF Research Database (Denmark)

    Rasmussen, Henrik B.; Bjerre, Ditte; Linnet, Kristian

    2015-01-01

    CES1 is involved in the hydrolysis of ester group-containing xenobiotic and endobiotic compounds including several essential and commonly used drugs. The individual variation in the efficacy and tolerability of many drugs metabolized by CES1 is considerable. Hence, there is a large interest in in...

  12. Electrochemical Oxidation by Square-Wave Potential Pulses in the Imitation of Oxidative Drug Metabolism

    NARCIS (Netherlands)

    Nouri-Nigjeh, Eslam; Permentier, Hjalmar P.; Bischoff, Rainer; Bruins, Andries P.

    2011-01-01

    Electrochemistry combined with mass spectrometry (EC-MS) is an emerging analytical technique in the imitation of oxidative drug metabolism at the early stages of new drug development. Here, we present the benefits of electrochemical oxidation by square-wave potential pulses for the oxidation of

  13. Computational drug design strategies applied to the modelling of human immunodeficiency virus-1 reverse transcriptase inhibitors

    Directory of Open Access Journals (Sweden)

    Lucianna Helene Santos

    2015-11-01

    Full Text Available Reverse transcriptase (RT is a multifunctional enzyme in the human immunodeficiency virus (HIV-1 life cycle and represents a primary target for drug discovery efforts against HIV-1 infection. Two classes of RT inhibitors, the nucleoside RT inhibitors (NRTIs and the nonnucleoside transcriptase inhibitors are prominently used in the highly active antiretroviral therapy in combination with other anti-HIV drugs. However, the rapid emergence of drug-resistant viral strains has limited the successful rate of the anti-HIV agents. Computational methods are a significant part of the drug design process and indispensable to study drug resistance. In this review, recent advances in computer-aided drug design for the rational design of new compounds against HIV-1 RT using methods such as molecular docking, molecular dynamics, free energy calculations, quantitative structure-activity relationships, pharmacophore modelling and absorption, distribution, metabolism, excretion and toxicity prediction are discussed. Successful applications of these methodologies are also highlighted.

  14. Human Drug Discrimination: Elucidating the Neuropharmacology of Commonly Abused Illicit Drugs.

    Science.gov (United States)

    Bolin, B Levi; Alcorn, Joseph L; Reynolds, Anna R; Lile, Joshua A; Stoops, William W; Rush, Craig R

    2016-06-07

    Drug-discrimination procedures empirically evaluate the control that internal drug states have over behavior. They provide a highly selective method to investigate the neuropharmacological underpinnings of the interoceptive effects of drugs in vivo. As a result, drug discrimination has been one of the most widely used assays in the field of behavioral pharmacology. Drug-discrimination procedures have been adapted for use with humans and are conceptually similar to preclinical drug-discrimination techniques in that a behavior is differentially reinforced contingent on the presence or absence of a specific interoceptive drug stimulus. This chapter provides a basic overview of human drug-discrimination procedures and reviews the extant literature concerning the use of these procedures to elucidate the underlying neuropharmacological mechanisms of commonly abused illicit drugs (i.e., stimulants, opioids, and cannabis) in humans. This chapter is not intended to review every available study that used drug-discrimination procedures in humans. Instead, when possible, exemplary studies that used a stimulant, opioid, or Δ 9 -tetrahydrocannabinol (the primary psychoactive constituent of cannabis) to assess the discriminative-stimulus effects of drugs in humans are reviewed for illustrative purposes. We conclude by commenting on the current state and future of human drug-discrimination research.

  15. In silico prediction of xenobiotic metabolism in humans

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Fangping [Los Alamos National Laboratory

    2009-01-01

    Xenobiotic metabolism in humans is catalyzed by a few enzymes with broad substrate specificities, which provide the overall broad chemical specificity for nearly all xenobiotics that humans encounter. Xenobiotic metabolism are classified into functional group biotransformations. Based on bona fide reactions and negative examples for each reaction class, support vector machine (SVM) classifiers are built. The input to SVM is a set of atomic and molecular features to define the electrostatic, steric, energetic, geometrical and topological environment of the atoms in the reaction center under the molecule. Results show that the overall sensitivity and specificity of classifiers is around 87%.

  16. The metabolism of the anti-inflammatory drug eterylate in rat, dog and man.

    Science.gov (United States)

    Wood, S G; John, B A; Chasseaud, L F; Johnstone, I; Biggs, S R; Hawkins, D R; Priego, J G; Darragh, A; Lambe, R F

    1983-12-01

    Oral doses of 14C-eterylate were well absorbed by rat and man and excreted mainly in the urine (94% dose by rat in three days and 91% by man in five days). Oral doses to dogs were excreted in similar proportions in both the urine and faeces, although faecal 14C was probably derived in part, from biliary-excreted material. Peak plasma 14C and drug concn. were generally reached between one and three hours after oral doses. In humans, only two metabolites, salicylic acid and 4-acetamido-phenoxyacetic acid, were detected in plasma. The latter was cleared more rapidly than the former and hence plasma salicyclate concn. reached a peak (10.9 and 19.8 micrograms/ml in Subjects 1 and 2, respectively) and initially declined with a half-life of about two-three hours. Plasma 4-acetamidophenoxyacetic acid concn. reached a peak (4.3, 10.0 micrograms/ml, respectively) and declined with a half-life of about one hour. Tissue concn. of 14C were generally greater in dogs than in rats. Highest conc. occurred at three hours in dogs and at one hour in rats. Apart from those in the liver and kidneys, tissue concn. were lower than those in the corresponding plasma. Unchanged drug was not detected in urine or plasma of any species and was rapidly metabolized in human plasma. The major 14C components in human urine were identified as salicyluric acid and 4-acetamidophenoxyacetic acid; minor metabolites were salicylic acid, gentisic acid and paracetamol. These metabolites were also detected in rat urine albeit in different proportions to those in human urine. Dog urine contained less of these metabolites and a major proportion of the 14C was associated with relatively non-polar components. Although salicylic acid and 4-acetamidophenoxyacetic acid were the only major circulating metabolites in man and rat, dog plasma also contained the non-polar urine metabolites.

  17. The pharmacokinetics and metabolism of lumiracoxib in chimeric humanized and murinized FRG mice.

    Science.gov (United States)

    Dickie, A P; Wilson, C E; Schreiter, K; Wehr, R; Wilson, E M; Bial, J; Scheer, N; Wilson, I D; Riley, R J

    2017-07-01

    The pharmacokinetics and metabolism of lumiracoxib were studied, after administration of single 10mg/kg oral doses to chimeric liver-humanized and murinized FRG mice. In the chimeric humanized mice, lumiracoxib reached peak observed concentrations in the blood of 1.10±0.08μg/mL at 0.25-0.5h post-dose with an AUC inf of 1.74±0.52μgh/mL and an effective half-life for the drug of 1.42±0.72h (n=3). In the case of the murinized animals peak observed concentrations in the blood were determined as 1.15±0.08μg/mL at 0.25h post-dose with an AUC inf of 1.94±0.22μgh/mL and an effective half-life of 1.28±0.02h (n=3). Analysis of blood indicated only the presence of unchanged lumiracoxib. Metabolic profiling of urine, bile and faecal extracts revealed a complex pattern of metabolites for both humanized and murinized animals with, in addition to unchanged parent drug, a variety of hydroxylated and conjugated metabolites detected. The profiles obtained in humanized mice were different compared to murinized animals with e.g., a higher proportion of the dose detected in the form of acyl glucuronide metabolites and much reduced amounts of taurine conjugates. Comparison of the metabolic profiles obtained from the present study with previously published data from C57bl/6J mice and humans, revealed a greater though not complete match between chimeric humanized mice and humans, such that the liver-humanized FRG model may represent a useful approach to assessing the biotransformation of such compounds in humans. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Cranberry juice suppressed the diclofenac metabolism by human liver microsomes, but not in healthy human subjects

    Science.gov (United States)

    Ushijima, Kentarou; Tsuruoka, Shu-ichi; Tsuda, Hidetoshi; Hasegawa, Gohki; Obi, Yuri; Kaneda, Tae; Takahashi, Masaki; Maekawa, Tomohiro; Sasaki, Tomohiro; Koshimizu, Taka-aki; Fujimura, Akio

    2009-01-01

    AIM To investigate a potential interaction between cranberry juice and diclofenac, a substrate of CYP2C9. METHODS The inhibitory effect of cranberry juice on diclofenac metabolism was determined using human liver microsome assay. Subsequently, we performed a clinical trial in healthy human subjects to determine whether the repeated consumption of cranberry juice changed the diclofenac pharmacokinetics. RESULTS Cranberry juice significantly suppressed diclofenac metabolism by human liver microsomes. On the other hand, repeated consumption of cranberry juice did not influence the diclofenac pharmacokinetics in human subjects. CONCLUSIONS Cranberry juice inhibited diclofenac metabolism by human liver microsomes, but not in human subjects. Based on the present and previous findings, we think that although cranberry juice inhibits CYP2C9 activity in vitro, it does not change the pharmacokinetics of medications metabolized by CYP2C9 in clinical situations. PMID:19694738

  19. Metabolism of lipoproteins by human fetal hepatocytes

    International Nuclear Information System (INIS)

    Carr, B.R.

    1987-01-01

    The rate of clearance of lipoproteins from plasma appears to play a role in the development of atherogenesis. The liver may account for as much as two thirds of the removal of low-density lipoprotein and one third of the clearance of high-density lipoprotein in certain animal species and humans, mainly by receptor-mediated pathways. The purpose of the present investigation was to determine if human fetal hepatocytes maintained in vitro take up and degrade lipoproteins. We first determined that the maximal binding capacity of iodine 125-iodo-LDL was approximately 300 ng of low-density lipoprotein protein/mg of membrane protein and an apparent dissociation constant of approximately 60 micrograms low-density lipoprotein protein/ml in membranes prepared from human fetal liver. We found that the maximal uptake of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL by fetal hepatocytes occurred after 12 hours of incubation. Low-density lipoprotein uptake preceded the appearance of degradation products by 4 hours, and thereafter the degradation of low-density lipoprotein increased linearly for at least 24 hours. In contrast, high-density lipoprotein was not degraded to any extent by fetal hepatocytes. [ 125 I]Iodo-LDL uptake and degradation were inhibited more than 75% by preincubation with low-density lipoprotein but not significantly by high-density lipoprotein, whereas [ 125 I]iodo-HDL uptake was inhibited 70% by preincubation with high-density lipoprotein but not by low-density lipoprotein. In summary, human fetal hepatocytes take up and degrade low-density lipoprotein by a receptor-mediated process similar to that described for human extrahepatic tissues

  20. Possible drug–drug interaction in dogs and cats resulted from alteration in drug metabolism: A mini review

    Directory of Open Access Journals (Sweden)

    Kazuaki Sasaki

    2015-05-01

    Full Text Available Pharmacokinetic drug–drug interactions (in particular at metabolism may result in fatal adverse effects in some cases. This basic information, therefore, is needed for drug therapy even in veterinary medicine, as multidrug therapy is not rare in canines and felines. The aim of this review was focused on possible drug–drug interactions in dogs and cats. The interaction includes enzyme induction by phenobarbital, enzyme inhibition by ketoconazole and fluoroquinolones, and down-regulation of enzymes by dexamethasone. A final conclusion based upon the available literatures and author’s experience is given at the end of the review.

  1. Metabolic heat production by human and animal populations in cities.

    Science.gov (United States)

    Stewart, Iain D; Kennedy, Chris A

    2017-07-01

    Anthropogenic heating from building energy use, vehicle fuel consumption, and human metabolism is a key term in the urban energy budget equation. Heating from human metabolism, however, is often excluded from urban energy budgets because it is widely observed to be negligible. Few reports for low-latitude cities are available to support this observation, and no reports exist on the contribution of domestic animals to urban heat budgets. To provide a more comprehensive view of metabolic heating in cities, we quantified all terms of the anthropogenic heat budget at metropolitan scale for the world's 26 largest cities, using a top-down statistical approach. Results show that metabolic heat release from human populations in mid-latitude cities (e.g. London, Tokyo, New York) accounts for 4-8% of annual anthropogenic heating, compared to 10-45% in high-density tropical cities (e.g. Cairo, Dhaka, Kolkata). Heat release from animal populations amounts to heating in all cities. Heat flux density from human and animal metabolism combined is highest in Mumbai-the world's most densely populated megacity-at 6.5 W m -2 , surpassing heat production by electricity use in buildings (5.8 W m -2 ) and fuel combustion in vehicles (3.9 W m -2 ). These findings, along with recent output from global climate models, suggest that in the world's largest and most crowded cities, heat emissions from human metabolism alone can force measurable change in mean annual temperature at regional scale.

  2. Functional interrogation of Plasmodium genus metabolism identifies species- and stage-specific differences in nutrient essentiality and drug targeting

    KAUST Repository

    Abdel-Haleem, Alyaa M.

    2018-01-04

    Several antimalarial drugs exist, but differences between life cycle stages among malaria species pose challenges for developing more effective therapies. To understand the diversity among stages and species, we reconstructed genome-scale models (GEMs) of metabolism for five life cycle stages and five species of Plasmodium spanning the blood, transmission, and mosquito stages. The stage-specific models of Plasmodium falciparum uncovered stage-dependent changes in central carbon metabolism and predicted potential targets that could affect several life cycle stages. The species-specific models further highlight differences between experimental animal models and the human-infecting species. Comparisons between human- and rodent-infecting species revealed differences in thiamine (vitamin B1), choline, and pantothenate (vitamin B5) metabolism. Thus, we show that genome-scale analysis of multiple stages and species of Plasmodium can prioritize potential drug targets that could be both anti-malarials and transmission blocking agents, in addition to guiding translation from non-human experimental disease models.

  3. Human Cytomegalovirus: Coordinating Cellular Stress, Signaling, and Metabolic Pathways.

    Science.gov (United States)

    Shenk, Thomas; Alwine, James C

    2014-11-01

    Viruses face a multitude of challenges when they infect a host cell. Cells have evolved innate defenses to protect against pathogens, and an infecting virus may induce a stress response that antagonizes viral replication. Further, the metabolic, oxidative, and cell cycle state may not be conducive to the viral infection. But viruses are fabulous manipulators, inducing host cells to use their own characteristic mechanisms and pathways to provide what the virus needs. This article centers on the manipulation of host cell metabolism by human cytomegalovirus (HCMV). We review the features of the metabolic program instituted by the virus, discuss the mechanisms underlying these dramatic metabolic changes, and consider how the altered program creates a synthetic milieu that favors efficient HCMV replication and spread.

  4. APP Metabolism Regulates Tau Proteostasis in Human Cerebral Cortex Neurons

    Directory of Open Access Journals (Sweden)

    Steven Moore

    2015-05-01

    Full Text Available Accumulation of Aβ peptide fragments of the APP protein and neurofibrillary tangles of the microtubule-associated protein tau are the cellular hallmarks of Alzheimer’s disease (AD. To investigate the relationship between APP metabolism and tau protein levels and phosphorylation, we studied human-stem-cell-derived forebrain neurons with genetic forms of AD, all of which increase the release of pathogenic Aβ peptides. We identified marked increases in intracellular tau in genetic forms of AD that either mutated APP or increased its dosage, suggesting that APP metabolism is coupled to changes in tau proteostasis. Manipulating APP metabolism by β-secretase and γ-secretase inhibition, as well as γ-secretase modulation, results in specific increases and decreases in tau protein levels. These data demonstrate that APP metabolism regulates tau proteostasis and suggest that the relationship between APP processing and tau is not mediated solely through extracellular Aβ signaling to neurons.

  5. TXNIP regulates peripheral glucose metabolism in humans

    DEFF Research Database (Denmark)

    Parikh, Hemang; Carlsson, Emma; Chutkow, William A

    2007-01-01

    combined human insulin/glucose clamp physiological studies with genome-wide expression profiling to identify thioredoxin interacting protein (TXNIP) as a gene whose expression is powerfully suppressed by insulin yet stimulated by glucose. In healthy individuals, its expression was inversely correlated...... expression is consistently elevated in the muscle of prediabetics and diabetics, although in a panel of 4,450 Scandinavian individuals, we found no evidence for association between common genetic variation in the TXNIP gene and T2DM. CONCLUSIONS: TXNIP regulates both insulin-dependent and insulin......-independent pathways of glucose uptake in human skeletal muscle. Combined with recent studies that have implicated TXNIP in pancreatic beta-cell glucose toxicity, our data suggest that TXNIP might play a key role in defective glucose homeostasis preceding overt T2DM....

  6. Cytochrome P450s: mechanisms and biological implications in drug metabolism and its interaction with oxidative stress.

    Science.gov (United States)

    Bhattacharyya, Sudip; Sinha, Krishnendu; Sil, Parames C

    2014-01-01

    Cytochrome monooxygenases P450 enzymes (CYPs) are terminal oxidases, belonging to the multi-gene family of heme-thiolate enzymes and located in multiple sites of ER, cytosol and mitochondria. CYPs act as catalysts in drugs metabolism. This review highlights the mitochondrial and microsomal CYPs metabolic functions, CYPs mediated ROS generation and its feedback, bioactivation of drugs and related hypersensitivity, metabolic disposition as well as the therapeutic approaches. CYPs mediated drugs bioactivation may trigger oxidative stress and cause pathophysiology. Almost all drugs show some adverse reactions at high doses or accidental overdoses. Drugs lead to hypersensitivity reactions while metabolic predisposition to drug hypersensitivity exaggerates it. Mostly different intermediate bioactive products of CYPs mediated drug metabolism is the principal issue in this respect. On the other hand, CYPs are the main source of ROS. Their generation and feedback are of major concern of this review. Besides drug metabolism, CYPs also contribute significantly to carcinogen metabolism. Ultimately other enzymes in drug metabolism and antioxidant therapy are indispensible. Importance of this field: In a global sense, understanding of exact mechanism can facilitate pharmaceutical industries' challenge of developing drugs without toxicity. Ultimate message: This review would accentuate the recent advances in molecular mechanism of CYPs mediated drug metabolism and complex cross-talks between various restorative novel strategies evolved by CYPs to sustain the redox balance and limit the source of oxidative stress.

  7. Regulation of drug-metabolizing enzymes in infectious and inflammatory disease: implications for biologics-small molecule drug interactions.

    Science.gov (United States)

    Mallick, Pankajini; Taneja, Guncha; Moorthy, Bhagavatula; Ghose, Romi

    2017-06-01

    Drug-metabolizing enzymes (DMEs) are primarily down-regulated during infectious and inflammatory diseases, leading to disruption in the metabolism of small molecule drugs (smds), which are increasingly being prescribed therapeutically in combination with biologics for a number of chronic diseases. The biologics may exert pro- or anti-inflammatory effect, which may in turn affect the expression/activity of DMEs. Thus, patients with infectious/inflammatory diseases undergoing biologic/smd treatment can have complex changes in DMEs due to combined effects of the disease and treatment. Areas covered: We will discuss clinical biologics-SMD interaction and regulation of DMEs during infection and inflammatory diseases. Mechanistic studies will be discussed and consequences on biologic-small molecule combination therapy on disease outcome due to changes in drug metabolism will be highlighted. Expert opinion: The involvement of immunomodulatory mediators in biologic-SMDs is well known. Regulatory guidelines recommend appropriate in vitro or in vivo assessments for possible interactions. The role of cytokines in biologic-SMDs has been documented. However, the mechanisms of drug-drug interactions is much more complex, and is probably multi-factorial. Studies aimed at understanding the mechanism by which biologics effect the DMEs during inflammation/infection are clinically important.

  8. Absorption and metabolic fate of bioactive dietary benzoxazinoids in humans

    DEFF Research Database (Denmark)

    Adhikari, Khem B; Laursen, Bente B; Gregersen, Per L

    2013-01-01

    benzoxazinoids with abundant HBOA-Glc (219 nmol × μmol−1 of creatinine). The sulfate and glucuronide conjugates of 2-hydroxy-1,4-benzoxazin-3-one (HBOA) and 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) were detected in plasma and urine, indicating substantial phase II metabolism. Direct absorption of lactam......Scope Benzoxazinoids, which are natural compounds recently identified in mature whole grain cereals and bakery products, have been suggested to have a range of pharmacological properties and health-protecting effects. There are no published reports concerned with the absorption and metabolism...... of bioactive benzoxazinoids in humans. Methods and results The absorption, metabolism, and excretion of ten different dietary benzoxazinoids were examined by LC-MS/MS by analyzing plasma and urine from 20 healthy human volunteers after daily intake of 143 μmol of total benzoxazinoids from rye bread and rye...

  9. Lipid metabolism in peroxisomes in relation to human disease

    NARCIS (Netherlands)

    Wanders, R. J.; Tager, J. M.

    1998-01-01

    Peroxisomes were long believed to play only a minor role in cellular metabolism but it is now clear that they catalyze a number of important functions. The importance of peroxisomes in humans is stressed by the existence of a group of genetic diseases in man in which one or more peroxisomal

  10. Human meniscal proteoglycan metabolism in long-term tissue culture

    NARCIS (Netherlands)

    Verbruggen, G.; Verdonk, R.; Veys, E. M.; van Daele, P.; de Smet, P.; van den Abbeele, K.; Claus, B.; Baeten, D.

    1996-01-01

    For the purpose of human meniscal allografting, menisci have been maintained viable in in vitro culture. The influence of long-term tissue culture on the extracellular matrix metabolism of the meniscus has been studied. Fetal calf serum (FCS) was used as a supplement for the growth factors necessary

  11. Endocrine and metabolic disorders associated with human immune deficiency virus infection.

    Science.gov (United States)

    Unachukwu, C N; Uchenna, D I; Young, E E

    2009-01-01

    Many reports have described endocrine and metabolic disorders in the human immunodeficiency virus (HIV) infection. This article reviewed various reports in the literature in order to increase the awareness and thus the need for early intervention when necessary. Data were obtained from MEDLINE, Google search and otherjournals on 'HIV, Endocrinopathies/Metabolic Disorders' from 1985 till 2007. Studies related to HIV associated endocrinopathies and metabolic disorders in the last two decades were reviewed. Information on epidemiology, pathogenesis, diagnosis and treatment of the target organ endocrinopathies and metabolic disorders in HIV/AIDS were extracted from relevant literature. Endocrine and metabolic disturbances occur in the course of HIV infection. Pathogenesis includes direct infection of endocrine glands by HIV or opportunistic organisms, infiltration by neoplasms and side effects of drugs. Adrenal insufficiency is the commonest HIV endocrinopathy with cytomegalovirus adrenalitis occurring in 40-88% of cases. Thyroid dysfunction may occur as euthyroid sick syndrome or sub-clinical hypothyroidism. Hypogonadotrophic dysfunction accounts for 75% of HIV-associated hypogonadism, with prolonged amenorrhoea being three times more likely in the women. Pancreatic dysfunction may result in hypoglycaemia or diabetes mellitus (DM). Highly active antiretroviral therapy (HAART) especially protease inhibitors has been noted to result in insulin resistance and lipodystrophy. Virtually every endocrine organ is involved in the course of HIV infection. Detailed endocrinological and metabolic evaluation and appropriate treatment is necessary in the optimal management of patients with HIV infection in our environment.

  12. Effect of saccharin on metabolic cooperation between human fibroblasts

    International Nuclear Information System (INIS)

    Mosser, D.D.; Bols, N.C.

    1983-01-01

    Autoradiography was used to study the effect of saccharin on metabolic cooperation between human diploid fibroblasts. When the donors, HGPRT+ cells, and recipients, HGPRT- cells, were plated together in the presence of saccharin, all the interactions that developed in 4 and 24 h were positive for metabolic cooperation. When saccharin was added after donor cells and recipient cells had made contact, the proportion of interactions that were positive for metabolic cooperation was unchanged but the number of grains over primary recipients was reduced. However, in donor cells saccharin caused a reduction in [ 3 H]hypoxanthine incorporation into both acid-soluble and acid-insoluble fractions, although the relative distribution of radioactivity between these two fractions and between the phosphorylated and non-phosphorylated derivatives of [ 3 H]hypoxanthine was unchanged. Metabolic cooperation was studied under conditions in which the number of grains over the nuclei of both the primary recipient and the primary recipient's donor could be counted. The change in the number of grains over these two cell types in response to saccharin was compared and found to be the same. Thus in normal human fibroblasts saccharin does not appear to affect metabolic cooperation, which is a measure of cell-to-cell communication

  13. Microbial metaproteomics for characterizing the range of metabolic functions and activities of human gut microbiota.

    Science.gov (United States)

    Xiong, Weili; Abraham, Paul E; Li, Zhou; Pan, Chongle; Hettich, Robert L

    2015-10-01

    The human gastrointestinal tract is a complex, dynamic ecosystem that consists of a carefully tuned balance of human host and microbiota membership. The microbiome is not merely a collection of opportunistic parasites, but rather provides important functions to the host that are absolutely critical to many aspects of health, including nutrient transformation and absorption, drug metabolism, pathogen defense, and immune system development. Microbial metaproteomics provides the ability to characterize the human gut microbiota functions and metabolic activities at a remarkably deep level, revealing information about microbiome development and stability as well as their interactions with their human host. Generally, microbial and human proteins can be extracted and then measured by high performance MS-based proteomics technology. Here, we review the field of human gut microbiome metaproteomics, with a focus on the experimental and informatics considerations involved in characterizing systems ranging from low-complexity model gut microbiota in gnotobiotic mice, to the emerging gut microbiome in the GI tract of newborn human infants, and finally to an established gut microbiota in human adults. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Antinociceptive effects, metabolism and disposition of ketamine in ponies under target-controlled drug infusion

    International Nuclear Information System (INIS)

    Knobloch, M.; Portier, C.J.; Levionnois, O.L.; Theurillat, R.; Thormann, W.; Spadavecchia, C.; Mevissen, M.

    2006-01-01

    Ketamine is widely used as an anesthetic in a variety of drug combinations in human and veterinary medicine. Recently, it gained new interest for use in long-term pain therapy administered in sub-anesthetic doses in humans and animals. The purpose of this study was to develop a physiologically based pharmacokinetic (PBPk) model for ketamine in ponies and to investigate the effect of low-dose ketamine infusion on the amplitude and the duration of the nociceptive withdrawal reflex (NWR). A target-controlled infusion (TCI) of ketamine with a target plasma level of 1 μg/ml S-ketamine over 120 min under isoflurane anesthesia was performed in Shetland ponies. A quantitative electromyographic assessment of the NWR was done before, during and after the TCI. Plasma levels of R-/S-ketamine and R-/S-norketamine were determined by enantioselective capillary electrophoresis. These data and two additional data sets from bolus studies were used to build a PBPk model for ketamine in ponies. The peak-to-peak amplitude and the duration of the NWR decreased significantly during TCI and returned slowly toward baseline values after the end of TCI. The PBPk model provides reliable prediction of plasma and tissue levels of R- and S-ketamine and R- and S-norketamine. Furthermore, biotransformation of ketamine takes place in the liver and in the lung via first-pass metabolism. Plasma concentrations of S-norketamine were higher compared to R-norketamine during TCI at all time points. Analysis of the data suggested identical biotransformation rates from the parent compounds to the principle metabolites (R- and S-norketamine) but different downstream metabolism to further metabolites. The PBPk model can provide predictions of R- and S-ketamine and norketamine concentrations in other clinical settings (e.g. horses)

  15. Antimalarial drug targets in Plasmodium falciparum predicted by stage-specific metabolic network analysis

    OpenAIRE

    Huthmacher, Carola; Hoppe, Andreas; Bulik, Sascha; Holzh?tter, Hermann-Georg

    2010-01-01

    Abstract Background Despite enormous efforts to combat malaria the disease still afflicts up to half a billion people each year of which more than one million die. Currently no approved vaccine is available and resistances to antimalarials are widely spread. Hence, new antimalarial drugs are urgently needed. Results Here, we present a computational analysis of the metabolism of Plasmodium falciparum, the deadliest malaria pathogen. We assembled a compartmentalized metabolic model and predicte...

  16. Developmental changes in drug-metabolizing enzyme expression during metamorphosis of Xenopus tropicalis.

    Science.gov (United States)

    Mori, Junpei; Sanoh, Seigo; Kashiwagi, Keiko; Hanada, Hideki; Shigeta, Mitsuki; Suzuki, Ken-Ichi T; Yamamoto, Takashi; Kotake, Yaichiro; Sugihara, Kazumi; Kitamura, Shigeyuki; Kashiwagi, Akihiko; Ohta, Shigeru

    2017-01-01

    A large number of chemicals are routinely detected in aquatic environments, and these chemicals may adversely affect aquatic organisms. Accurate risk assessment requires understanding drug-metabolizing systems in aquatic organisms because metabolism of these chemicals is a critical determinant of chemical bioaccumulation and related toxicity. In this study, we evaluated mRNA expression levels of nuclear receptors and drug-metabolizing enzymes as well as cytochrome P450 (CYP) activities in pro-metamorphic tadpoles, froglets, and adult frogs to determine how drug-metabolizing systems are altered at different life stages. We found that drug-metabolizing systems in tadpoles were entirely immature, and therefore, tadpoles appeared to be more susceptible to chemicals compared with metamorphosed frogs. On the other hand, cyp1a mRNA expression and CYP1A-like activity were higher in tadpoles. We found that thyroid hormone (TH), which increases during metamorphosis, induced CYP1A-like activity. Because endogenous TH concentration is significantly increased during metamorphosis, endogenous TH would induce CYP1A-like activity in tadpoles.

  17. Forensic relevance of glucuronidation in phase-II-metabolism of alcohols and drugs.

    Science.gov (United States)

    Kaeferstein, Herbert

    2009-04-01

    Forensic toxicology means detecting toxic or pharmacologically active substances in body fluids and organs and the evaluation and judgement of the respective results. In the legal judgement, not only the taken in active drugs, but also their metabolites are to be included. Regarding metabolism one distinguishes phase-I- and phase-II-metabolism. In the phase-I-metabolism, active substances are converted by oxidation, reduction or hydrolysis, but influencing the polarity of more lipophilic substances often not decisively. The pharmacological activity is often preserved or even increased. In phase-II-metabolism a highly hydrophilic substance--mostly glucuronic acid--is coupled to the active substances or the respective phase-I-metabolites. This reaction step decisively increases hydrophilicity of lipophilic substances, thus enhancing renal elimination and often also abolishing pharmacologically and/or toxicologically effects. Nevertheless the interaction of different drugs and alcohols in glucuronidation and the glucuronides of phase-II-metabolism still do not play a substantial role in the forensic-toxicological analysis and interpretation of results so far. However, in vitro investigations since 1999 in our lab show that such interactions are not unlikely. For valid interpretation of complex cases in the future it may become necessary not only to quantify drugs and the phase-I-metabolites but also the phase-II-metabolites and discuss possible interactions in the metabolism.

  18. Redox-based Epigenetic status in Drug Addiction: Potential mediator of drug-induced gene priming phenomenon and use of metabolic intervention for symptomatic treatment in drug addiction.

    Directory of Open Access Journals (Sweden)

    Malav Suchin Trivedi

    2015-01-01

    Full Text Available Alcohol and other drugs of abuse, including psychostimulants and opioids, can induce epigenetic changes: a contributing factor for drug addiction, tolerance and associated withdrawal symptoms. DNA methylation is the major epigenetic mechanism and it is one of more than 200 methylation reactions supported by methyl donor S-adenosylmethionine (SAM. The levels of SAM are controlled by cellular redox status via the folate and vitamin B12-dependent enzyme methionine synthase (MS, for example; under oxidative conditions MS is inhibited, diverting its substrate homocysteine (HCY to the transsulfuration pathway. Alcohol, dopamine and morphine, can alter intracellular levels of glutathione (GSH-based cellular redox status, subsequently affecting S-adenosylmethionine (SAM levels and DNA methylation status. In this discussion, we compile this and other existing evidence in a coherent manner to present a novel hypothesis implicating the involvement of redox-based epigenetic changes in drug addiction. Next, we also discuss how gene priming phenomenon can contribute to maintenance of redox and methylation status homeostasis under various stimuli including drugs of abuse. Lastly, based on our hypothesis and some preliminary evidence, we discuss a mechanistic explanation for use of metabolic interventions / redox-replenishers as symptomatic treatment of alcohol addiction and associated withdrawal symptoms. Hence, the current review article strengthens the hypothesis that neuronal metabolism has a critical bidirectional coupling with epigenetic changes in drug addiction and we support this claim via exemplifying the link between redox-based metabolic changes and resultant epigenetic consequences under the effect of drugs of abuse.

  19. Interplay of drug metabolism and transport: a real phenomenon or an artifact of the site of measurement?

    Science.gov (United States)

    Endres, Christopher J; Endres, Michael G; Unadkat, Jashvant D

    2009-01-01

    The interdependence of both transport and metabolism on the disposition of drugs has recently gained heightened attention in the literature, and has been termed the "interplay of transport and metabolism". Such "interplay" is observed when inhibition of biliary clearance of a drug results in an "apparent" increase in the metabolic clearance of the drug or vice versa. In this manuscript, we derived and explored through simulations a physiological-based pharmacokinetic model that integrates both transport and metabolism and explains the "apparent" dependence of hepatic clearance on both these processes. In addition, we show that the phenomenon of hepatic "transport-metabolism interplay" is a result of using the plasma concentration as a point of reference when calculating metabolic or biliary clearance, and this interplay is maximal when the drug is actively transported into the hepatocytes (i.e., hepatocyte sinusoidal influx clearance is greater than the sinusoidal efflux clearance). When the hepatic drug concentration is used as a reference point to calculate metabolic or biliary clearance, this interplay ceases to exist. A mechanistic understanding of this interplay phenomenon can be used to explain the somewhat paradoxical results that may be observed in drug-drug interaction studies when a drug is cleared by both metabolism and biliary excretion. That is, when one of these two pathways is inhibited, the other pathway appears to be induced or activated. This interplay results in an increase in hepatic drug concentrations and therefore has implications for the hepatic efficacy and toxicity of a drug.

  20. Genome-scale reconstruction of the Streptococcus pyogenes M49 metabolic network reveals growth requirements and indicates potential drug targets.

    Science.gov (United States)

    Levering, Jennifer; Fiedler, Tomas; Sieg, Antje; van Grinsven, Koen W A; Hering, Silvio; Veith, Nadine; Olivier, Brett G; Klett, Lara; Hugenholtz, Jeroen; Teusink, Bas; Kreikemeyer, Bernd; Kummer, Ursula

    2016-08-20

    Genome-scale metabolic models comprise stoichiometric relations between metabolites, as well as associations between genes and metabolic reactions and facilitate the analysis of metabolism. We computationally reconstructed the metabolic network of the lactic acid bacterium Streptococcus pyogenes M49. Initially, we based the reconstruction on genome annotations and already existing and curated metabolic networks of Bacillus subtilis, Escherichia coli, Lactobacillus plantarum and Lactococcus lactis. This initial draft was manually curated with the final reconstruction accounting for 480 genes associated with 576 reactions and 558 metabolites. In order to constrain the model further, we performed growth experiments of wild type and arcA deletion strains of S. pyogenes M49 in a chemically defined medium and calculated nutrient uptake and production fluxes. We additionally performed amino acid auxotrophy experiments to test the consistency of the model. The established genome-scale model can be used to understand the growth requirements of the human pathogen S. pyogenes and define optimal and suboptimal conditions, but also to describe differences and similarities between S. pyogenes and related lactic acid bacteria such as L. lactis in order to find strategies to reduce the growth of the pathogen and propose drug targets. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Respiratory compensation to a primary metabolic alkalosis in humans.

    Science.gov (United States)

    Feldman, Mark; Alvarez, Naiara M; Trevino, Michael; Weinstein, Gary L

    2012-11-01

    There is limited and disparate information about the extent of the respiratory compensation (hypoventilation) that occurs in response to a primary metabolic alkalosis in humans. Our aim was to examine the influence of the plasma bicarbonate concentration, the plasma base excess, and the arterial pH on the arterial carbon dioxide tension in 52 adult patients with primary metabolic alkalosis, mostly due to diuretic use or vomiting. Linear regression analysis was used to correlate degrees of alkalosis with arterial carbon dioxide tensions. In this alkalotic cohort, whose arterial plasma bicarbonate averaged 31.6 mEq/l, plasma base excess averaged 7.8 mEq/l, and pH averaged 7.48, both plasma bicarbonate and base excess correlated closely with arterial carbon dioxide tensions (r = 0.97 and 0.96, respectively; p respiratory compensation (hypoventilation) to primary metabolic alkalosis than has been reported in prior smaller studies.

  2. A review of metabolic potential of human gut microbiome in human nutrition.

    Science.gov (United States)

    Yadav, Monika; Verma, Manoj Kumar; Chauhan, Nar Singh

    2018-03-01

    The human gut contains a plethora of microbes, providing a platform for metabolic interaction between the host and microbiota. Metabolites produced by the gut microbiota act as a link between gut microbiota and its host. These metabolites act as messengers having the capacity to alter the gut microbiota. Recent advances in the characterization of the gut microbiota and its symbiotic relationship with the host have provided a platform to decode metabolic interactions. The human gut microbiota, a crucial component for dietary metabolism, is shaped by the genetic, epigenetic and dietary factors. The metabolic potential of gut microbiota explains its significance in host health and diseases. The knowledge of interactions between microbiota and host metabolism, as well as modification of microbial ecology, is really beneficial to have effective therapeutic treatments for many diet-related diseases in near future. This review cumulates the information to map the role of human gut microbiota in dietary component metabolism, the role of gut microbes derived metabolites in human health and host-microbe metabolic interactions in health and diseases.

  3. Applications of deuterium labeling in studies of drug metabolism: metabolism of trideuteroaniline mustard

    International Nuclear Information System (INIS)

    Cox, P.J.; Farmer, P.B.; Foster, A.B.; Jarman, M.

    1977-01-01

    In a continuation of a study of aniline mustard, the metabolism of 2,4,6-trideuteroaniline mustard [N-N-di-(2-chloroethyl)-2,4,6-trideuteroaniline] was investigated. Measurements of the ratios of deuterated to nondeuterated species in p-hydroxyaniline mustard and N-(2-chloroethyl)-4-hydroxyaniline isolated following in vitro metabolism of a mixture of aniline mustard and aniline mustard-d 3 enabled a determination both of the kinetic isotope effect and of the extents of NIH shifts and indicated the probable metabolite sequence

  4. Assessing the Metabolic Effects of Aromatherapy in Human Volunteers

    Directory of Open Access Journals (Sweden)

    Yinan Zhang

    2013-01-01

    Full Text Available Aromatherapy, a form of complementary and alternative medicine (CAM that uses essential oils through inhalation, is believed to enhance physical and spiritual conditions. Although clinical studies suggest that the use of essential oils may have therapeutic potential, evidence for the efficacy of aromatherapy in treating medical conditions remains poor, with a particular lack of studies employing rigorous analytical methods that capture its identifiable impact on human biology. Here, we report a comprehensive metabolomics study that reveals metabolic changes in people after exposed to aroma inhalation for 10 continuous days. In this study, the metabolic alterations in urine of 31 females with mild anxiety symptoms exposed to aerial diffusion of aromas were measured by GC-TOF-MS and UPLC-Q-TOF-MS analyses. A significant alteration of metabolic profile in subjects responsive to essential oil was found, which is characterized by the increased levels of arginine, homocysteine, and betaine, as well as decreased levels of alcohols, carbohydrates, and organic acids in urine. Notably, the metabolites from tricarboxylic acid (TCA cycle and gut microbial metabolism were significantly altered. This study demonstrates that the metabolomics approach can capture the subtle metabolic changes resulting from exposure to essential oils, which may lead to an improved mechanistic understanding of aromatherapy.

  5. Metabolic interaction between toluene, trichloroethylene and n-hexane in humans

    DEFF Research Database (Denmark)

    Bælum, Jesper; Mølhave, Lars; Hansen, S H

    1998-01-01

    This human experimental study describes the mutual metabolic interaction between toluene, trichloroethylene, and n-hexane.......This human experimental study describes the mutual metabolic interaction between toluene, trichloroethylene, and n-hexane....

  6. Multidirectional vector pathways of vitamin D metabolism as modifiers of its interaction with drugs

    Directory of Open Access Journals (Sweden)

    O.M. Nikolova

    2018-02-01

    Full Text Available Background. The comorbid pathology characteristic of the elderly and senile people may lead to polypharmacy. The leading role in the metabolism of drugs is played by the cytochrome (CY P450 system. The use of vitamin D in geriatric patients is of particular importance taking into account their age-specific features of metabolism. The purpose of the review was to analyse the international contemporary information content on the interaction of vitamin D with the system of metabolism of the drugs. Materials and methods. Analysis of American and European scientific sources was performed. Results. More than 11,500 proteins of the CYP system are currently described. In the metabolism of medicines, the following six are involved: CYP1A2, CYP2C19, CYP2C9, CYP2D6, CYP2E1, CYP3A4, which provide biotransformation of drugs through oxidation. CYP450 is a hemoprotein that provides binding of the substrate molecules with activation of oxygens, resulting in the formation of oxidation, a more hydrophilic product and water molecule. The insufficiency of hydroxylation capacity of the liver and kidneys can lead to D-hypovitaminosis in the body of patients. CYP11A1, СYР27А1, СYР27В1, СYР24А1 are responsible for vitamin D metabolism. Conducted studies have shown that these cytochromes metabolize a number of other drugs that can act as their inhibitors and inducers. Conclusions. The system of cytochrome P450 influences the formation of vitamin D metabolites. Taking into account the physiological ways of its metabolism, multidirectional results of interaction are formed.

  7. Human Rights and Wrongs in Iran's Drug Diplomacy with Europe

    DEFF Research Database (Denmark)

    Christensen, Janne Bjerre

    2017-01-01

    Europe has a strong interest in and a history of assisting Iran in controlling inflows of drugs from Afghanistan. But due to Iran's increasing use of the death penalty in drug trafficking cases, Europe has terminated its cooperation. Based on interviews with Iranian policy......-makers and representatives of both human rights organizations and the United Nations Office on Drugs and Crime (UNODC), this article presents Denmark's withdrawal of drug control funding in 2013 as a case study, analyzing the dilemmas and trajectories of joint Iranian-European drug diplomacy and the prospects...

  8. Comparative study of hop-containing products on human cytochrome p450-mediated metabolism.

    Science.gov (United States)

    Foster, Brian C; Kearns, Nikia; Arnason, John T; Saleem, Ammar; Ogrodowczyk, Carolina; Desjardins, Suzanne

    2009-06-10

    Thirty-five national and international brands of beer were examined for their potential to affect human cytochrome P450 (CYP)-mediated metabolism. They represented the two main categories of beer, ales and lagers, and included a number of specialty products including bitter (porter, stout), coffee, ice, wheat, Pilsner, and hemp seed. Aliquots were examined for nonvolatile soluble solids, effect on CYP metabolism and P-glycoprotein (Pgp) transport, and major alpha- and beta-hop acids. Wide variance was detected in contents of alcohol, nonvolatile suspended solids, and hop acids and in the potential to affect CYP-mediated metabolism and Pgp-mediated efflux transport. Many of the products affected CYP2C9-mediated metabolism, and only two (NRP 306 and 307) markedly affected CYP3A4; hence, some products have the capacity to affect drug safety. CYP3A4, CYP3A5, CYP3A7, and CYP19 (aromatase) inhibition to the log concentration of beta-acid content was significant with r(2) > 0.37, suggesting that these components can account for some of the variation in inhibition of CYP metabolism.

  9. People who use drugs, HIV, and human rights.

    Science.gov (United States)

    Jürgens, Ralf; Csete, Joanne; Amon, Joseph J; Baral, Stefan; Beyrer, Chris

    2010-08-07

    We reviewed evidence from more than 900 studies and reports on the link between human rights abuses experienced by people who use drugs and vulnerability to HIV infection and access to services. Published work documents widespread abuses of human rights, which increase vulnerability to HIV infection and negatively affect delivery of HIV programmes. These abuses include denial of harm-reduction services, discriminatory access to antiretroviral therapy, abusive law enforcement practices, and coercion in the guise of treatment for drug dependence. Protection of the human rights of people who use drugs therefore is important not only because their rights must be respected, protected, and fulfilled, but also because it is an essential precondition to improving the health of people who use drugs. Rights-based responses to HIV and drug use have had good outcomes where they have been implemented, and they should be replicated in other countries. Copyright 2010 Elsevier Ltd. All rights reserved.

  10. Human basophil degranulation test in drug allergy.

    Science.gov (United States)

    Sastre Domínguez, J; Sastre Castillo, A

    1986-01-01

    We have evaluated the usefulness of HBDT as an in vitro method for the diagnosis of drug allergy. Two hundred and thirty six patients with suspected drug sensitization to penicillin, streptomycin, sulfamides, pyrazolones and A.S.A. were analyzed. Seventy-nine of them were allergic; in 43 cases it was confirmed by in vivo methods. Other patients were diagnosed by clinical history only if they had more than two reactions to the same drug. In order to be included in this group patients with reactions to pyrazolones and A.S.A. had to have tolerated other NSAI, therefore these patients were allergic to one compound only. All patients were considered non-allergic were determined by a negative provocation test. In the group of allergic patients we obtained 63 (79%) positive degranulations and 16 (21%) negative. One hundred and thirty two (84%) negative degranulations and 25 (16%) positive were obtained in the group of non-allergic patients. Once having analyzed 10 statistical parameters with each drug, the HBOT appears to be a useful method for these drugs except for streptomycin. In 16 (80%) out of 20 aspirin sensitive asthmatic patients we found that their basophils were degranulated. In 7 patients with urticaria and/or angioedema by A.S.A. and other NSAI the degranulation was negative, confirming the absence of the involvement of basophils in this reactions.

  11. Metabolic control of muscle blood flow during exercise in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher

    2003-01-01

    that combined blockade of NOS and PGI2, and NOS and cytochrome P450, both attenuate exercise-induced hyperemia in humans. Combined vasodilator blockade studies offer the potential to uncover important interactions and compensatory vasodilator responses. The signaling pathways that link metabolic events evoked...... to exert control of muscle vasodilation. Adenosine, nitric oxide (NO), prostacyclin (PGI2), and endothelial-derived hyperpolarization factor (EDHF) are possible mediators of muscle vasodilation during exercise. In humans, adenosine has been shown to contribute to functional hyperemia as blood flow...... by muscle contraction to vasodilatory signals in the local vascular bed remains an important area of study....

  12. Reconstruction of genome-scale human metabolic models using omics data

    DEFF Research Database (Denmark)

    Ryu, Jae Yong; Kim, Hyun Uk; Lee, Sang Yup

    2015-01-01

    used to describe metabolic phenotypes of healthy and diseased human tissues and cells, and to predict therapeutic targets. Here we review recent trends in genome-scale human metabolic modeling, including various generic and tissue/cell type-specific human metabolic models developed to date, and methods......, databases and platforms used to construct them. For generic human metabolic models, we pay attention to Recon 2 and HMR 2.0 with emphasis on data sources used to construct them. Draft and high-quality tissue/cell type-specific human metabolic models have been generated using these generic human metabolic...... refined through gap filling, reaction directionality assignment and the subcellular localization of metabolic reactions. We review relevant tools for this model refinement procedure as well. Finally, we suggest the direction of further studies on reconstructing an improved human metabolic model....

  13. Systems biology of human metabolism - Defining the epithelial to mesenchymal transition and the activity of human gluconokinase

    OpenAIRE

    Rohatgi, Neha

    2016-01-01

    Studying human metabolism is crucial for the understanding of diseases and improvement of therapy as metabolic alterations are central to a number of human diseases. A variety of experimental disciplines, such as biochemistry, biophysics and systems biology are involved in the elucidation of metabolic pathways. The work presented in this thesis is divided into three main studies, which expand the knowledge of human metabolism using systems biology and biochemical techniques....

  14. Successful Use of [14C]Paracetamol Microdosing to Elucidate Developmental Changes in Drug Metabolism

    NARCIS (Netherlands)

    M.G. Mooij (Miriam); E. van Duijn (Esther); C.A.J. Knibbe (Catherijne); K.M. Allegaert (Karel); J. Windhorst (Judith); J.M. van Rosmalen (Joost); N.H. Hendrikse (N. Harry); D. Tibboel (Dick); W.H.J. Vaes (Wouter H. J.); S.N. de Wildt (Saskia)

    2017-01-01

    textabstractBackground: We previously showed the practical and ethical feasibility of using [14C]-microdosing for pharmacokinetic studies in children. We now aimed to show that this approach can be used to elucidate developmental changes in drug metabolism, more specifically, glucuronidation and

  15. Successful Use of [(14)C]Paracetamol Microdosing to Elucidate Developmental Changes in Drug Metabolism

    NARCIS (Netherlands)

    Mooij, M.G.; Duijn, E. van; Knibbe, C.A.; Allegaert, K.; Windhorst, A.D.; Rosmalen, J. van; Hendrikse, N.H.; Tibboel, D.; Vaes, W.H.; Wildt, S.N. de

    2017-01-01

    BACKGROUND: We previously showed the practical and ethical feasibility of using [(14)C]-microdosing for pharmacokinetic studies in children. We now aimed to show that this approach can be used to elucidate developmental changes in drug metabolism, more specifically, glucuronidation and sulfation,

  16. Cryopreservation of Precision-cut Tissue Slices for Application in Drug Metabolism Research

    NARCIS (Netherlands)

    Graaf, Inge Anne Maria de

    2002-01-01

    The research described in this thesis had two important aims. The first was to determine whether tissue slices could be used as an in vitro tool to predict the in vivo metabolism of new drugs. The second aim was to find a manner to store tissue slices for longer time periods by cryopreservation.

  17. Glutathione metabolism modelling: a mechanism for liver drug-robustness and a new biomarker strategy

    NARCIS (Netherlands)

    Geenen, S.; du Preez, F.B.; Snoep, J.L.; Foster, A.J.; Sarda, S.; Kenna, J.G.; Wilson, I.D.; Westerhoff, H.V.

    2013-01-01

    Background Glutathione metabolism can determine an individual's ability to detoxify drugs. To increase understanding of the dynamics of cellular glutathione homeostasis, we have developed an experiment-based mathematical model of the kinetics of the glutathione network. This model was used to

  18. 131I metabolism in the study of antithyroid drug

    International Nuclear Information System (INIS)

    Gagliardi, R.P.; Santalla de Pirovano, M. del C.; Kramar de Valmaggia, E.P.; Valsecchi, R.; Pisarev, Mario; Altschuler, Noe

    1977-11-01

    The main purpose of the present report was to study the action of antithyroid drugs on different parameters of thyroid activity utilizing 131 I, in the offsprings of rats treated during pregnancy and the perinatal period. Both PTU and MMI caused alterations in growth and thyroid activity, but they were more dramatic with the former. A significative increase in 131 I thyroid uptake and in circulating radioactivity was observed. When % uptake was expressed as a function of thyroidal and body weights, a significative decrease was noticed. The ratio T/S and the percentage of labelled iodothyronines in pancreatin digests were also decreased. Neuromuscular maturation was evaluated, by means of the test of Schapiro. A group of animals treated with PTU plus T 4 had a significant delay, reaching normal developement later than the controls or those treated with MMI. (author) [es

  19. Quantitation of small intestinal permeability during normal human drug absorption

    OpenAIRE

    Levitt, David G

    2013-01-01

    Background Understanding the quantitative relationship between a drug?s physical chemical properties and its rate of intestinal absorption (QSAR) is critical for selecting candidate drugs. Because of limited experimental human small intestinal permeability data, approximate surrogates such as the fraction absorbed or Caco-2 permeability are used, both of which have limitations. Methods Given the blood concentration following an oral and intravenous dose, the time course of intestinal absorpti...

  20. Studies on drug metabolism by use of isotopes, 22

    International Nuclear Information System (INIS)

    Horie, Masanobu; Baba, Shigeo

    1978-01-01

    The human urinary metabolites of 3-phenylpropyl carbamate (I) were analysed by using an ion cluster technique. After oral administration of an equimolar mixture of non-labeled I and deuterium labeled I, neutral metabolites were extracted with ethyl acetate at pH 7.0, trimethylsilylated and subjected to gas chromatograph-mass spectrometer. In the case of the analysis of acidic metabolites, the urine of human receiving deuterium labeled I alone was used. The obtained acidic metabolites were methylated with diazomethane and subjected to gas chromatograph-mass spectrometer. As neutral metabolites, 3-hydroxy-3-phenylpropyl carbamate 2,3-dihydroxy-3-phenylpropyl carbamate and 3,4'-dihydroxy-3-phenylpropyl carbamate were identified. Unchanged I, however, was not detected. Benzoic and hippuric acids originated from I could be clearly distinguished from the corresponding compounds endogenously produced. (auth.)

  1. A RAPID THIN-LAYER CHROMATOGRAPHIC PROCEDURE TO IDENTIFY POOR AND EXTENSIVE OXIDATIVE DRUG METABOLIZERS IN MAN USING DEXTROMETHORPHAN

    NARCIS (Netherlands)

    DEZEEUW, RA; EIKEMA, D; FRANKE, JP; JONKMAN, JHG

    A rapid TLC method is presented to distinguish poor oxidative drug metabolizers from extensive oxidative drug metabolizers. Dextromethorphan (1) is used as test probe because it is safe, well characterized, generally available and easy to measure. The method is based on the extraction of 1 and its

  2. Effects of Curcuma xanthorrhiza Extracts and Their Constituents on Phase II Drug-metabolizing Enzymes Activity.

    Science.gov (United States)

    Salleh, Nurul Afifah Mohd; Ismail, Sabariah; Ab Halim, Mohd Rohaimi

    2016-01-01

    Curcuma xanthorrhiza is a native Indonesian plant and traditionally utilized for a range of illness including liver damage, hypertension, diabetes, and cancer. The study determined the effects of C. xanthorrhiza extracts (ethanol and aqueous) and their constituents (curcumene and xanthorrhizol) on UDP-glucuronosyltransferase (UGT) and glutathione transferase (GST) activities. The inhibition studies were evaluated both in rat liver microsomes and in human recombinant UGT1A1 and UGT2B7 enzymes. p-nitrophenol and beetle luciferin were used as the probe substrates for UGT assay while 1-chloro-2,4-dinitrobenzene as the probe for GST assay. The concentrations of extracts studied ranged from 0.1 to 1000 μg/mL while for constituents ranged from 0.01 to 500 μM. In rat liver microsomes, UGT activity was inhibited by the ethanol extract (IC 50 =279.74 ± 16.33 μg/mL). Both UGT1A1 and UGT2B7 were inhibited by the ethanol and aqueous extracts with IC 50 values ranging between 9.59-22.76 μg/mL and 110.71-526.65 μg/Ml, respectively. Rat liver GST and human GST Pi-1 were inhibited by ethanol and aqueous extracts, respectively (IC 50 =255.00 ± 13.06 μg/mL and 580.80 ± 18.56 μg/mL). Xanthorrhizol was the better inhibitor of UGT1A1 (IC 50 11.30 ± 0.27 μM) as compared to UGT2B7 while curcumene did not show any inhibition. For GST, both constituents did not show any inhibition. These findings suggest that C. xanthorrhiza have the potential to cause herb-drug interaction with drugs that are primarily metabolized by UGT and GST enzymes. Findings from this study would suggest which of Curcuma xanthorrhiza extracts and constituents that would have potential interactions with drugs which are highly metabolized by UGT and GST enzymes. Further clinical studies can then be designed if needed to evaluate the in vivo pharmacokinetic relevance of these interactions Abbreviations Used : BSA: Bovine serum albumin, CAM: Complementary and alternative medicine, cDNA: Complementary

  3. Effects of Curcuma xanthorrhiza Extracts and Their Constituents on Phase II Drug-metabolizing Enzymes Activity

    Science.gov (United States)

    Salleh, Nurul Afifah Mohd; Ismail, Sabariah; Ab Halim, Mohd Rohaimi

    2016-01-01

    Background: Curcuma xanthorrhiza is a native Indonesian plant and traditionally utilized for a range of illness including liver damage, hypertension, diabetes, and cancer. Objective: The study determined the effects of C. xanthorrhiza extracts (ethanol and aqueous) and their constituents (curcumene and xanthorrhizol) on UDP-glucuronosyltransferase (UGT) and glutathione transferase (GST) activities. Materials and Methods: The inhibition studies were evaluated both in rat liver microsomes and in human recombinant UGT1A1 and UGT2B7 enzymes. p-nitrophenol and beetle luciferin were used as the probe substrates for UGT assay while 1-chloro-2,4-dinitrobenzene as the probe for GST assay. The concentrations of extracts studied ranged from 0.1 to 1000 μg/mL while for constituents ranged from 0.01 to 500 μM. Results: In rat liver microsomes, UGT activity was inhibited by the ethanol extract (IC50 =279.74 ± 16.33 μg/mL). Both UGT1A1 and UGT2B7 were inhibited by the ethanol and aqueous extracts with IC50 values ranging between 9.59–22.76 μg/mL and 110.71–526.65 μg/Ml, respectively. Rat liver GST and human GST Pi-1 were inhibited by ethanol and aqueous extracts, respectively (IC50 =255.00 ± 13.06 μg/mL and 580.80 ± 18.56 μg/mL). Xanthorrhizol was the better inhibitor of UGT1A1 (IC50 11.30 ± 0.27 μM) as compared to UGT2B7 while curcumene did not show any inhibition. For GST, both constituents did not show any inhibition. Conclusion: These findings suggest that C. xanthorrhiza have the potential to cause herb-drug interaction with drugs that are primarily metabolized by UGT and GST enzymes. SUMMARY Findings from this study would suggest which of Curcuma xanthorrhiza extracts and constituents that would have potential interactions with drugs which are highly metabolized by UGT and GST enzymes. Further clinical studies can then be designed if needed to evaluate the in vivo pharmacokinetic relevance of these interactions Abbreviations Used: BSA: Bovine serum albumin

  4. Metabolomics analysis of metabolic effects of nicotinamide phosphoribosyltransferase (NAMPT inhibition on human cancer cells.

    Directory of Open Access Journals (Sweden)

    Vladimir Tolstikov

    Full Text Available Nicotinamide phosphoribosyltransferase (NAMPT plays an important role in cellular bioenergetics. It is responsible for converting nicotinamide to nicotinamide adenine dinucleotide, an essential molecule in cellular metabolism. NAMPT has been extensively studied over the past decade due to its role as a key regulator of nicotinamide adenine dinucleotide-consuming enzymes. NAMPT is also known as a potential target for therapeutic intervention due to its involvement in disease. In the current study, we used a global mass spectrometry-based metabolomic approach to investigate the effects of FK866, a small molecule inhibitor of NAMPT currently in clinical trials, on metabolic perturbations in human cancer cells. We treated A2780 (ovarian cancer and HCT-116 (colorectal cancer cell lines with FK866 in the presence and absence of nicotinic acid. Significant changes were observed in the amino acids metabolism and the purine and pyrimidine metabolism. We also observed metabolic alterations in glycolysis, the citric acid cycle (TCA, and the pentose phosphate pathway. To expand the range of the detected polar metabolites and improve data confidence, we applied a global metabolomics profiling platform by using both non-targeted and targeted hydrophilic (HILIC-LC-MS and GC-MS analysis. We used Ingenuity Knowledge Base to facilitate the projection of metabolomics data onto metabolic pathways. Several metabolic pathways showed differential responses to FK866 based on several matches to the list of annotated metabolites. This study suggests that global metabolomics can be a useful tool in pharmacological studies of the mechanism of action of drugs at a cellular level.

  5. Drug policy, harm and human rights: a rationalist approach.

    Science.gov (United States)

    Stevens, Alex

    2011-05-01

    It has recently been argued that drug-related harms cannot be compared, so making it impossible to choose rationally between various drug policy options. Attempts to apply international human rights law to this area are valid, but have found it difficult to overcome the problems in applying codified human rights to issues of drug policy. This article applies the rationalist ethical argument of Gewirth (1978) to this issue. It outlines his argument to the 'principle of generic consistency' and the hierarchy of basic, nonsubtractive and additive rights that it entails. It then applies these ideas to drug policy issues, such as whether there is a right to use drugs, whether the rights of drug 'addicts' can be limited, and how different harms can be compared in choosing between policies. There is an additive right to use drugs, but only insofar as this right does not conflict with the basic and nonsubtractive rights of others. People whose freedom to choose whether to use drugs is compromised by compulsion have a right to receive treatment. They retain enforceable duties not to inflict harms on others. Policies which reduce harms to basic and nonsubtractive rights should be pursued, even if they lead to harms to additive rights. There exists a sound, rational, extra-legal basis for the discussion of drug policy and related harms which enables commensurable discussion of drug policy options. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. APP metabolism regulates tau proteostasis in human cerebral cortex neurons.

    Science.gov (United States)

    Moore, Steven; Evans, Lewis D B; Andersson, Therese; Portelius, Erik; Smith, James; Dias, Tatyana B; Saurat, Nathalie; McGlade, Amelia; Kirwan, Peter; Blennow, Kaj; Hardy, John; Zetterberg, Henrik; Livesey, Frederick J

    2015-05-05

    Accumulation of Aβ peptide fragments of the APP protein and neurofibrillary tangles of the microtubule-associated protein tau are the cellular hallmarks of Alzheimer's disease (AD). To investigate the relationship between APP metabolism and tau protein levels and phosphorylation, we studied human-stem-cell-derived forebrain neurons with genetic forms of AD, all of which increase the release of pathogenic Aβ peptides. We identified marked increases in intracellular tau in genetic forms of AD that either mutated APP or increased its dosage, suggesting that APP metabolism is coupled to changes in tau proteostasis. Manipulating APP metabolism by β-secretase and γ-secretase inhibition, as well as γ-secretase modulation, results in specific increases and decreases in tau protein levels. These data demonstrate that APP metabolism regulates tau proteostasis and suggest that the relationship between APP processing and tau is not mediated solely through extracellular Aβ signaling to neurons. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Metabolism-Activated Multitargeting (MAMUT): An Innovative Multitargeting Approach to Drug Design and Development.

    Science.gov (United States)

    Mátyus, Péter; Chai, Christina L L

    2016-06-20

    Multitargeting is a valuable concept in drug design for the development of effective drugs for the treatment of multifactorial diseases. This concept has most frequently been realized by incorporating two or more pharmacophores into a single hybrid molecule. Many such hybrids, due to the increased molecular size, exhibit unfavorable physicochemical properties leading to adverse effects and/or an inappropriate ADME (absorption, distribution, metabolism, and excretion) profile. To avoid this limitation and achieve additional therapeutic benefits, here we describe a novel multitargeting strategy based on the synergistic effects of a parent drug and its active metabolite(s). The concept of metabolism-activated multitargeting (MAMUT) is illustrated using a number of examples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tumor regression with a combination of drugs interfering with the tumor metabolism: efficacy of hydroxycitrate, lipoic acid and capsaicin.

    Science.gov (United States)

    Schwartz, Laurent; Guais, Adeline; Israël, Maurice; Junod, Bernard; Steyaert, Jean-Marc; Crespi, Elisabetta; Baronzio, Gianfranco; Abolhassani, Mohammad

    2013-04-01

    Cellular metabolic alterations are now well described as implicated in cancer and some strategies are currently developed to target these different pathways. In previous papers, we demonstrated that a combination of molecules (namely alpha-lipoic acid and hydroxycitrate, i.e. Metabloc™) targeting the cancer metabolism markedly decreased tumor cell growth in mice. In this work, we demonstrate that the addition of capsaicin further delays tumor growth in mice in a dose dependant manner. This is true for the three animal model tested: lung (LLC) cancer, bladder cancer (MBT-2) and melanoma B16F10. There was no apparent side effect of this ternary combination. The addition of a fourth drug (octreotide) is even more effective resulting in tumor regression in mice bearing LLC cancer. These four compounds are all known to target the cellular metabolism not its DNA. The efficacy, the apparent lack of toxicity, the long clinical track records of these medications in human medicine, all points toward the need for a clinical trial. The dramatic efficacy of treatment suggests that cancer may simply be a disease of dysregulated cellular metabolism.

  9. Effects of naturally occurring coumarins on hepatic drug-metabolizing enzymes inmice

    International Nuclear Information System (INIS)

    Kleiner, Heather E.; Xia, Xiaojun; Sonoda, Junichiro; Zhang, Jun; Pontius, Elizabeth; Abey, Jane; Evans, Ronald M.; Moore, David D.; DiGiovanni, John

    2008-01-01

    Cytochromes P450 (P450s) and glutathione S-transferases (GSTs) constitute two important enzyme families involved in carcinogen metabolism. Generally, P450s play activation or detoxifying roles while GSTs act primarily as detoxifying enzymes. We previously demonstrated that oral administration of the linear furanocoumarins, isopimpinellin and imperatorin, modulated P450 and GST activities in various tissues of mice. The purpose of the present study was to compare a broader range of naturally occurring coumarins (simple coumarins, and furanocoumarins of the linear and angular type) for their abilities to modulate hepatic drug-metabolizing enzymes when administered orally to mice. We now report that all of the different coumarins tested (coumarin, limettin, auraptene, angelicin, bergamottin, imperatorin and isopimpinellin) induced hepatic GST activities, whereas the linear furanocoumarins possessed the greatest abilities to induce hepatic P450 activities, in particular P450 2B and 3A. In both cases, this corresponded to an increase in protein expression of the enzymes. Induction of P4502B10, 3A11, and 2C9 by xenobiotics often is a result of activation of the pregnane X receptor (PXR) and/or constitutive androstane receptor (CAR). Using a pregnane X receptor reporter system, our results demonstrated that isopimpinellin activated both PXR and its human ortholog SXR by recruiting coactivator SRC-1 in transfected cells. In CAR transfection assays, isopimpinellin counteracted the inhibitory effect of androstanol on full-length mCAR, a Gal4-mCAR ligand-binding domain fusion, and restored coactivator binding. Orally administered isopimpinellin induced hepatic mRNA expression of Cyp2b10, Cyp3a11, and GSTa in CAR(+/+) wild-type mice. In contrast, the induction of Cyp2b10 mRNA by isopimpinellin was attenuated in the CAR(-/-) mice, suggesting that isopimpinellin induces Cyp2b10 via the CAR receptor. Overall, the current data indicate that naturally occurring coumarins have

  10. Lack of effect of spinal anesthesia on drug metabolism

    International Nuclear Information System (INIS)

    Whelan, E.; Wood, A.J.; Shay, S.; Wood, M.

    1989-01-01

    The effect of spinal anesthesia on drug disposition was determined in six dogs with chronically implanted vascular catheters using propranolol as a model compound. On the first study day, 40 mg of unlabeled propranolol and 200 microCi of [3H]propranolol were injected into the portal and femoral veins respectively. Arterial blood samples were taken for 4 hr for measurement of plasma concentrations of labeled and unlabeled propranolol by high-pressure liquid chromatography (HPLC) and of [3H]propranolol by liquid scintillation counting of the HPLC eluant corresponding to each propranolol peak. Twenty-four hr later, spinal anesthesia was induced with tetracaine (mean dose 20.7 +/- 0.6 mg) with low sacral to midthoracic levels and the propranolol infusions and sampling were then repeated. Spinal anesthesia had no significant effect on either the intrinsic clearance of propranolol (2.01 +/- 0.75 L/min before and 1.9 +/- 0.7 L/min during spinal anesthesia), or on mean hepatic plasma flow (2.01 +/- 0.5 L/min before and 1.93 +/- 0.5 L/min during spinal anesthesia). The systemic clearance and elimination half-life of propranolol were also unchanged by spinal anesthesia (0.9 +/- 0.23 L/min on the first day, 0.7 +/- 0.1 L/min during spinal anesthesia; and 101 +/- 21 min on the first day, 115 +/- 16 min during spinal anesthesia, respectively). The volume of distribution (Vd) of propranolol was similarly unaffected by spinal anesthesia

  11. Human Metabolic Enzymes Deficiency: A Genetic Mutation Based Approach

    Directory of Open Access Journals (Sweden)

    Swati Chaturvedi

    2016-01-01

    Full Text Available One of the extreme challenges in biology is to ameliorate the understanding of the mechanisms which emphasize metabolic enzyme deficiency (MED and how these pretend to have influence on human health. However, it has been manifested that MED could be either inherited as inborn error of metabolism (IEM or acquired, which carries a high risk of interrupted biochemical reactions. Enzyme deficiency results in accumulation of toxic compounds that may disrupt normal organ functions and cause failure in producing crucial biological compounds and other intermediates. The MED related disorders cover widespread clinical presentations and can involve almost any organ system. To sum up the causal factors of almost all the MED-associated disorders, we decided to embark on a less traveled but nonetheless relevant direction, by focusing our attention on associated gene family products, regulation of their expression, genetic mutation, and mutation types. In addition, the review also outlines the clinical presentations as well as diagnostic and therapeutic approaches.

  12. The human NAD metabolome: Functions, metabolism and compartmentalization

    Science.gov (United States)

    Nikiforov, Andrey; Kulikova, Veronika; Ziegler, Mathias

    2015-01-01

    Abstract The metabolism of NAD has emerged as a key regulator of cellular and organismal homeostasis. Being a major component of both bioenergetic and signaling pathways, the molecule is ideally suited to regulate metabolism and major cellular events. In humans, NAD is synthesized from vitamin B3 precursors, most prominently from nicotinamide, which is the degradation product of all NAD-dependent signaling reactions. The scope of NAD-mediated regulatory processes is wide including enzyme regulation, control of gene expression and health span, DNA repair, cell cycle regulation and calcium signaling. In these processes, nicotinamide is cleaved from NAD+ and the remaining ADP-ribosyl moiety used to modify proteins (deacetylation by sirtuins or ADP-ribosylation) or to generate calcium-mobilizing agents such as cyclic ADP-ribose. This review will also emphasize the role of the intermediates in the NAD metabolome, their intra- and extra-cellular conversions and potential contributions to subcellular compartmentalization of NAD pools. PMID:25837229

  13. Hepatitis C, human immunodeficiency virus and metabolic syndrome: interactions.

    Science.gov (United States)

    Kotler, Donald P

    2009-03-01

    Significant concerns have been raised about the metabolic effects of antiretroviral medication, including the classic triad of dyslipidaemia, insulin resistance (IR) and characteristic alterations in fat distribution (lipoatrophy and lipohypertrophy). Co-infection with hepatitis C appears to exacerbate IR, reduce serum lipids and induce prothrombotic changes in the treated human immunodeficiency virus patient. The effects of co-infection are complex. While combination antiretroviral therapy has been shown to be associated with an increased risk of cardiovascular events through promotion of dyslipidaemia, IR and fat redistribution, co-infection exacerbates IR while reducing serum lipids. Co-infection also promotes a prothrombotic state characterized by endothelial dysfunction and platelet activation, which may enhance risk for cardiovascular disease. Consideration must be given to selection of appropriate treatment regimens and timing of therapy in co-infected patients to minimize metabolic derangements and, ultimately, reduce cardiovascular risk.

  14. Predictivity of dog co-culture model, primary human hepatocytes and HepG2 cells for the detection of hepatotoxic drugs in humans

    International Nuclear Information System (INIS)

    Atienzar, Franck A.; Novik, Eric I.; Gerets, Helga H.; Parekh, Amit; Delatour, Claude; Cardenas, Alvaro; MacDonald, James; Yarmush, Martin L.; Dhalluin, Stéphane

    2014-01-01

    Drug Induced Liver Injury (DILI) is a major cause of attrition during early and late stage drug development. Consequently, there is a need to develop better in vitro primary hepatocyte models from different species for predicting hepatotoxicity in both animals and humans early in drug development. Dog is often chosen as the non-rodent species for toxicology studies. Unfortunately, dog in vitro models allowing long term cultures are not available. The objective of the present manuscript is to describe the development of a co-culture dog model for predicting hepatotoxic drugs in humans and to compare the predictivity of the canine model along with primary human hepatocytes and HepG2 cells. After rigorous optimization, the dog co-culture model displayed metabolic capacities that were maintained up to 2 weeks which indicates that such model could be also used for long term metabolism studies. Most of the human hepatotoxic drugs were detected with a sensitivity of approximately 80% (n = 40) for the three cellular models. Nevertheless, the specificity was low approximately 40% for the HepG2 cells and hepatocytes compared to 72.7% for the canine model (n = 11). Furthermore, the dog co-culture model showed a higher superiority for the classification of 5 pairs of close structural analogs with different DILI concerns in comparison to both human cellular models. Finally, the reproducibility of the canine system was also satisfactory with a coefficient of correlation of 75.2% (n = 14). Overall, the present manuscript indicates that the dog co-culture model may represent a relevant tool to perform chronic hepatotoxicity and metabolism studies. - Highlights: • Importance of species differences in drug development. • Relevance of dog co-culture model for metabolism and toxicology studies. • Hepatotoxicity: higher predictivity of dog co-culture vs HepG2 and human hepatocytes

  15. Predictivity of dog co-culture model, primary human hepatocytes and HepG2 cells for the detection of hepatotoxic drugs in humans

    Energy Technology Data Exchange (ETDEWEB)

    Atienzar, Franck A., E-mail: franck.atienzar@ucb.com [UCB Pharma SA, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l' Alleud (Belgium); Novik, Eric I. [H mu rel Corporation, 675 U.S. Highway 1, North Brunswick, NJ 08902 (United States); Gerets, Helga H. [UCB Pharma SA, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l' Alleud (Belgium); Parekh, Amit [H mu rel Corporation, 675 U.S. Highway 1, North Brunswick, NJ 08902 (United States); Delatour, Claude; Cardenas, Alvaro [UCB Pharma SA, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l' Alleud (Belgium); MacDonald, James [Chrysalis Pharma Consulting, LLC, 385 Route 24, Suite 1G, Chester, NJ 07930 (United States); Yarmush, Martin L. [Department of Biomedical Engineering, Rutgers University, Piscataway, NJ 08854 (United States); Dhalluin, Stéphane [UCB Pharma SA, Non-Clinical Development, Chemin du Foriest, 1420 Braine-l' Alleud (Belgium)

    2014-02-15

    Drug Induced Liver Injury (DILI) is a major cause of attrition during early and late stage drug development. Consequently, there is a need to develop better in vitro primary hepatocyte models from different species for predicting hepatotoxicity in both animals and humans early in drug development. Dog is often chosen as the non-rodent species for toxicology studies. Unfortunately, dog in vitro models allowing long term cultures are not available. The objective of the present manuscript is to describe the development of a co-culture dog model for predicting hepatotoxic drugs in humans and to compare the predictivity of the canine model along with primary human hepatocytes and HepG2 cells. After rigorous optimization, the dog co-culture model displayed metabolic capacities that were maintained up to 2 weeks which indicates that such model could be also used for long term metabolism studies. Most of the human hepatotoxic drugs were detected with a sensitivity of approximately 80% (n = 40) for the three cellular models. Nevertheless, the specificity was low approximately 40% for the HepG2 cells and hepatocytes compared to 72.7% for the canine model (n = 11). Furthermore, the dog co-culture model showed a higher superiority for the classification of 5 pairs of close structural analogs with different DILI concerns in comparison to both human cellular models. Finally, the reproducibility of the canine system was also satisfactory with a coefficient of correlation of 75.2% (n = 14). Overall, the present manuscript indicates that the dog co-culture model may represent a relevant tool to perform chronic hepatotoxicity and metabolism studies. - Highlights: • Importance of species differences in drug development. • Relevance of dog co-culture model for metabolism and toxicology studies. • Hepatotoxicity: higher predictivity of dog co-culture vs HepG2 and human hepatocytes.

  16. Human folate metabolism using 14C-accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Arjomand, A; Bucholz, B A; Clifford, A J; Duecker, S R; Johnson, H; Schneider, P D; Zulim, R A.

    1999-01-01

    Folate is a water soluble vitamin required for optimal health, growth and development. It occurs naturally in various states of oxidation of the pteridine ring and with varying lengths to its glutamate chain. Folates function as one-carbon donors through methyl transferase catalyzed reactions. Low-folate diets, especially by those with suboptimal methyltransferase activity, are associated with increased risk of neural tube birth defects in children, hyperhomocysteinemic heart disease, and cancer in adults. Rapidly dividing (neoplastic) cells have a high folate need for DNA synthesis. Chemical analogs of folate (antifolates) that interfere with folate metabolism are used as therapeutic agents in cancer treatment. Although much is known about folate chemistry, metabolism of this vitamin in vivo in humans is not well understood. Since folate levels in blood and tissues are very low and methods to measure them are inadequate, the few previous studies that have examined folate metabolism used large doses of radiolabeled folic acid in patients with Hodgkins disease and cancer (Butterworth et al. 1969, Krumdieck et al. 1978). A subsequent protocol using deuterated folic acid was also insufficiently sensitive to trace a physiologic folate dose (Stites et al. 1997). Accelerator mass spectrometry (AMS) is an emerging bioanalytical tool that overcomes the limitations of traditional mass spectrometry and of decay counting of long lived radioisotopes (Vogel et al. 1995). AMS can detect attomolar concentrations of 14 C in milligram-sized samples enabling in vivo radiotracer studies in healthy humans. We used AMS to study the metabolism of a physiologic 80 nmol oral dose of 14 C-folic acid (1/6 US RDA) by measuring the 14 C-folate levels in serial plasma, urine and feces samples taken over a 150-day period after dosing a healthy adult volunteer

  17. Accelerating Precision Drug Development and Drug Repurposing by Leveraging Human Genetics.

    Science.gov (United States)

    Pulley, Jill M; Shirey-Rice, Jana K; Lavieri, Robert R; Jerome, Rebecca N; Zaleski, Nicole M; Aronoff, David M; Bastarache, Lisa; Niu, Xinnan; Holroyd, Kenneth J; Roden, Dan M; Skaar, Eric P; Niswender, Colleen M; Marnett, Lawrence J; Lindsley, Craig W; Ekstrom, Leeland B; Bentley, Alan R; Bernard, Gordon R; Hong, Charles C; Denny, Joshua C

    2017-04-01

    The potential impact of using human genetic data linked to longitudinal electronic medical records on drug development is extraordinary; however, the practical application of these data necessitates some organizational innovations. Vanderbilt has created resources such as an easily queried database of >2.6 million de-identified electronic health records linked to BioVU, which is a DNA biobank with more than 230,000 unique samples. To ensure these data are used to maximally benefit and accelerate both de novo drug discovery and drug repurposing efforts, we created the Accelerating Drug Development and Repurposing Incubator, a multidisciplinary think tank of experts in various therapeutic areas within both basic and clinical science as well as experts in legal, business, and other operational domains. The Incubator supports a diverse pipeline of drug indication finding projects, leveraging the natural experiment of human genetics.

  18. Bioprinting of Micro-Organ Tissue Analog for Drug Metabolism Study

    Science.gov (United States)

    Sun, Wei

    An evolving application of tissue engineering is to develop in vitro 3D cell/tissue models for drug screening and pharmacological study. In order to test in space, these in vitro models are mostly manufactured through micro-fabrication techniques and incorporate living cells with MEMS or microfluidic devices. These cell-integrated microfluidic devices, or referred as microorgans, are effective in furnishing reliable and inexpensive drug metabolism and toxicity studies [1-3]. This paper will present an on-going research collaborated between Drexel University and NASA JSC Radiation Physics Laboratory for applying a direct cell printing technique to freeform fabrication of 3D liver tissue analog in drug metabolism study. The paper will discuss modeling, design, and solid freeform fabrication of micro-fluidic flow patterns and bioprinting of 3D micro-liver chamber that biomimics liver physiological microenvironment for enhanced drug metabolization. Technical details to address bioprinting of 3D liver tissue analog, integration with a microfluidic device, and basic drug metabolism study for NASA's interests will presented. 1. Holtorf H. Leslie J. Chang R, Nam J, Culbertson C, Sun W, Gonda S, "Development of a Three-Dimensional Tissue-on-a-Chip Micro-Organ Device for Pharmacokinetic Analysis", the 47th Annual Meeting of the American Society for Cell Biology, Washington, DC, December 1-5, 2007. 2. Chang, R., Nam, J., Culbertson C., Holtorf, H., Jeevarajan, A., Gonda, S. and Sun, W., "Bio-printing and Modeling of Flow Patterns for Cell Encapsulated 3D Liver Chambers For Pharmacokinetic Study", TERMIS North America 2007 Conference and Exposition, Westin Harbour Castle, Toronto, Canada, June 13-16, 2007. 3.Starly, B., Chang, R., Sun, W., Culbertson, C., Holtorf, H. and Gonda, S., "Bioprinted Tissue-on-chip Application for Pharmacokinetic Studies", Proceedings of World Congress on Tissue Engineering and Regenerative Medicine, Pittsburgh, PA, USA, April 24-27, 2006.

  19. Behavioral Pharmacology of Human Drug Dependence

    Science.gov (United States)

    1981-07-01

    1978. pp. 1-37. Pickens, I., Thompson, T., and Muchow, D.C. Cannabis and phenoy- olidine self-adinistration by animals. In: Goldberg, L., and...phenyl- ethylamines: cocaine, caffeine , and nicotine. Cocaine maintained high levels of self-infusion performance through a broader range of doses than...any of the 16 other drugs tested (0.032-3.2 mg/kg). Figure 2 shows that mean levels of self-infusion of both nicotine and caffeine were within the

  20. Susceptibility of human head and neck cancer cells to combined inhibition of glutathione and thioredoxin metabolism.

    Directory of Open Access Journals (Sweden)

    Arya Sobhakumari

    Full Text Available Increased glutathione (GSH and thioredoxin (Trx metabolism are mechanisms that are widely implicated in resistance of cancer cells to chemotherapy. The current study determined if simultaneous inhibition of GSH and Trx metabolism enhanced cell killing of human head and neck squamous cell carcinoma (HNSCC cells by a mechanism involving oxidative stress. Inhibition of GSH and Trx metabolism with buthionine sulfoximine (BSO and auranofin (AUR, respectively, induced significant decreases in clonogenic survival compared to either drug alone in FaDu, Cal-27 and SCC-25 HNSCC cells in vitro and in vivo in Cal-27 xenografts. BSO+AUR significantly increased glutathione and thioredoxin oxidation and suppressed peroxiredoxin activity in vitro. Pre-treatment with N-acetylcysteine completely reversed BSO+AUR-induced cell killing in FaDu and Cal-27 cells, while catalase and selenium supplementation only inhibited BSO+AUR-induced cell killing in FaDu cells. BSO+AUR decreased caspase 3/7 activity in HNSCC cells and significantly reduced the viability of both Bax/Bak double knockout (DKO and DKO-Bax reconstituted hematopoietic cells suggesting that necrosis was involved. BSO+AUR also significantly sensitized FaDu, Cal-27, SCC-25 and SQ20B cells to cell killing induced by the EGFR inhibitor Erlotinib in vitro. These results support the conclusion that simultaneous inhibition of GSH and Trx metabolism pathways induces oxidative stress and clonogenic killing in HNSCCs and this strategy may be useful in sensitizing HNSCCs to EGFR inhibitors.

  1. Metabolic and Pharmacokinetic Differentiation of STX209 and Racemic Baclofen in Humans

    Directory of Open Access Journals (Sweden)

    Raymundo Sanchez-Ponce

    2012-09-01

    Full Text Available STX209 is an exploratory drug comprising the single, active R-enantiomer of baclofen which is in later stage clinical trials for the treatment of fragile x syndrome (FXS and autism spectrum disorders (ASD. New clinical data in this article on the metabolism and pharmacokinetics of the R- and S-enantiomers of baclofen presents scientific evidence for stereoselective metabolism of only S-baclofen to an abundant oxidative deamination metabolite that is sterically resolved as the S-enantiomeric configuration. This metabolite undergoes some further metabolism by glucuronide conjugation. Consequences of this metabolic difference are a lower Cmax and lower early plasma exposure of S-baclofen compared to R-baclofen and marginally lower urinary excretion of S-baclofen after racemic baclofen administration. These differences introduce compound-related exposure variances in humans in which subjects dosed with racemic baclofen are exposed to a prominent metabolite of baclofen whilst subjects dosed with STX209 are not. For potential clinical use, our findings suggest that STX209 has the advantage of being a biologically defined and active enantiomer.

  2. Richness of human gut microbiome correlates with metabolic markers

    DEFF Research Database (Denmark)

    Le Chatelier, Emmanuelle; Nielsen, Trine; Qin, Junjie

    2013-01-01

    We are facing a global metabolic health crisis provoked by an obesity epidemic. Here we report the human gut microbial composition in a population sample of 123 non-obese and 169 obese Danish individuals. We find two groups of individuals that differ by the number of gut microbial genes and thus ...... and obese participants. Our classifications based on variation in the gut microbiome identify subsets of individuals in the general white adult population who may be at increased risk of progressing to adiposity-associated co-morbidities....

  3. Metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy LSD (O-H-LSD) in human liver microsomes and cryopreserved human hepatocytes.

    Science.gov (United States)

    Klette, K L; Anderson, C J; Poch, G K; Nimrod, A C; ElSohly, M A

    2000-10-01

    The metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy lysergic acid diethylamide (O-H-LSD) was investigated in liver microsomes and cyropreserved hepatocytes from humans. Previous studies have demonstrated that O-H-LSD is present in human urine at concentrations 16-43 times greater than LSD, the parent compound. Additionally, these studies have determined that O-H-LSD is not generated during the specimen extraction and analytical processes or due to parent compound degradation in aqueous urine samples. However, these studies have not been conclusive in demonstrating that O-H-LSD is uniquely produced during in vivo metabolism. Phase I drug metabolism was investigated by incubating human liver microsomes and cryopreserved human hepatocytes with LSD. The reaction was quenched at various time points, and the aliquots were extracted using liquid partitioning and analyzed by liquid chromatography-mass spectrometry. O-H-LSD was positively identified in all human liver microsomal and human hepatocyte fractions incubated with LSD. In addition, O-H-LSD was not detected in any microsomal or hepatocyte fraction not treated with LSD nor in LSD specimens devoid of microsomes or hepatocytes. This study provides definitive evidence that O-H-LSD is produced as a metabolic product following incubation of human liver microsomes and hepatocytes with LSD.

  4. Mechanistic studies of the metabolic chiral inversion of (R)-ibuprofen in humans

    International Nuclear Information System (INIS)

    Baillie, T.A.; Adams, W.J.; Kaiser, D.G.; Olanoff, L.S.; Halstead, G.W.; Harpootlian, H.; Van Giessen, G.J.

    1989-01-01

    The metabolic chiral inversion of R-(-)-ibuprofen has been studied in human subjects by means of specific deuterium labeling and stereoselective gas chromatography-mass spectrometry methodology. After simultaneous p.o. administration of a mixture of R-(-)-ibuprofen (300 mg) and R-(-)-[3,3,3-2H3]ibuprofen (304 mg) to four adult male volunteers, the enantiomeric composition and deuterium content of the drug in serum, and of the drug and its principal metabolites in urine, were followed over a period of 24 hr. The results of these analyses indicated that: (1) conversion of R-(-)- to S-(+)-ibuprofen takes place with complete retention of deuterium at the beta-methyl (C-3) position; (2) chiral inversion of R-(-)-[2H3]ibuprofen is not subject to a discernible deuterium isotope effect; and (3) replacement of the beta-methyl hydrogen atoms by deuterium has no effect on any of the serum pharmacokinetic parameters for R-(-)- or S-(+)-ibuprofen. These data indicate that the process whereby R-(-)-ibuprofen undergoes metabolic inversion in human subjects does not involve 2,3-dehydroibuprofen as an intermediate, and that the underlying mechanism cannot, therefore, entail a desaturation/reduction sequence

  5. Diurnal variation of the human adipose transcriptome and the link to metabolic disease

    Directory of Open Access Journals (Sweden)

    Lamb John

    2009-02-01

    Full Text Available Abstract Background Circadian (diurnal rhythm is an integral part of the physiology of the body; specifically, sleep, feeding behavior and metabolism are tightly linked to the light-dark cycle dictated by earth's rotation. Methods The present study examines the effect of diurnal rhythm on gene expression in the subcutaneous adipose tissue of overweight to mildly obese, healthy individuals. In this well-controlled clinical study, adipose biopsies were taken in the morning, afternoon and evening from individuals in three study arms: treatment with the weight loss drug sibutramine/fasted, placebo/fed and placebo/fasted. Results The results indicated that diurnal rhythm was the most significant driver of gene expression variation in the human adipose tissue, with at least 25% of the genes having had significant changes in their expression levels during the course of the day. The mRNA expression levels of core clock genes at a specific time of day were consistent across multiple subjects on different days in all three arms, indicating robust diurnal regulation irrespective of potential confounding factors. The genes essential for energy metabolism and tissue physiology were part of the diurnal signature. We hypothesize that the diurnal transition of the expression of energy metabolism genes reflects the shift in the adipose tissue from an energy-expending state in the morning to an energy-storing state in the evening. Consistent with this hypothesis, the diurnal transition was delayed by fasting and treatment with sibutramine. Finally, an in silico comparison of the diurnal signature with data from the publicly-available Connectivity Map demonstrated a significant association with transcripts that were repressed by mTOR inhibitors, suggesting a possible link between mTOR signaling, diurnal gene expression and metabolic regulation. Conclusion Diurnal rhythm plays an important role in the physiology and regulation of energy metabolism in the adipose

  6. Obesity-related metabolic dysfunction in dogs: a comparison with human metabolic syndrome.

    Science.gov (United States)

    Tvarijonaviciute, Asta; Ceron, Jose J; Holden, Shelley L; Cuthbertson, Daniel J; Biourge, Vincent; Morris, Penelope J; German, Alexander J

    2012-08-28

    Recently, metabolic syndrome (MS) has gained attention in human metabolic medicine given its associations with development of type 2 diabetes mellitus and cardiovascular disease. Canine obesity is associated with the development of insulin resistance, dyslipidaemia, and mild hypertension, but the authors are not aware of any existing studies examining the existence or prevalence of MS in obese dogs.Thirty-five obese dogs were assessed before and after weight loss (median percentage loss 29%, range 10-44%). The diagnostic criteria of the International Diabetes Federation were modified in order to define canine obesity-related metabolic dysfunction (ORMD), which included a measure of adiposity (using a 9-point body condition score [BCS]), systolic blood pressure, fasting plasma cholesterol, plasma triglyceride, and fasting plasma glucose. By way of comparison, total body fat mass was measured by dual-energy X-ray absorptiometry, whilst total adiponectin, fasting insulin, and high-sensitivity C-reactive protein (hsCRP) were measured using validated assays. Systolic blood pressure (P = 0.008), cholesterol (P = 0.003), triglyceride (P = 0.018), and fasting insulin (P disease associations and outcomes of weight loss.

  7. Human skeletal muscle drug transporters determine local exposure and toxicity of statins.

    Science.gov (United States)

    Knauer, Michael J; Urquhart, Bradley L; Meyer zu Schwabedissen, Henriette E; Schwarz, Ute I; Lemke, Christopher J; Leake, Brenda F; Kim, Richard B; Tirona, Rommel G

    2010-02-05

    The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, are important drugs used in the treatment and prevention of cardiovascular disease. Although statins are well tolerated, many patients develop myopathy manifesting as muscle aches and pain. Rhabdomyolysis is a rare but severe toxicity of statins. Interindividual differences in the activities of hepatic membrane drug transporters and metabolic enzymes are known to influence statin plasma pharmacokinetics and risk for myopathy. Interestingly, little is known regarding the molecular determinants of statin distribution into skeletal muscle and its relevance to toxicity. We sought to identify statin transporters in human skeletal muscle and determine their impact on statin toxicity in vitro. We demonstrate that the uptake transporter OATP2B1 (human organic anion transporting polypeptide 2B1) and the efflux transporters, multidrug resistance-associated protein (MRP)1, MRP4, and MRP5 are expressed on the sarcolemmal membrane of human skeletal muscle fibers and that atorvastatin and rosuvastatin are substrates of these transporters when assessed using a heterologous expression system. In an in vitro model of differentiated, primary human skeletal muscle myoblast cells, we demonstrate basal membrane expression and drug efflux activity of MRP1, which contributes to reducing intracellular statin accumulation. Furthermore, we show that expression of human OATP2B1 in human skeletal muscle myoblast cells by adenoviral vectors increases intracellular accumulation and toxicity of statins and such effects were abrogated when cells overexpressed MRP1. These results identify key membrane transporters as modulators of skeletal muscle statin exposure and toxicity.

  8. The effect of phorbols on metabolic cooperation between human fibroblasts

    International Nuclear Information System (INIS)

    Mosser, D.D.; Bols, N.C.

    1982-01-01

    Autoradiography has been used to study the effect of 12-O-tetradecanoylphorbol-13-acetate (TPA), 4-O-methyl TPA, and phorbol on metabolic cooperation between human diploid fibroblasts. When the donors, hypoxanthine-guanine phosphoribosyl transferase+ (HGPRT+) cells, and recipients, HGPRT- cells, were plated together in the presence of [ 3 H]hypoxanthine and either 4-O-methyl TPA or phorbol, nearly all interactions that developed in 4 h were positive for metabolic cooperation whereas when high concentrations of TPA were used, the number of positive interactions was significantly less than the control. If the phorbol analogs were added after the donors and recipients had made contact, the number of positive interactions was the same as the control in all cases. However, although primary recipients in the cultures that had been treated with phorbol had the same number of grains as those in the control, primary recipients in cultures that had been treated with TPA or high concentrations of 4-O-methyl TPA had significantly fewer grains than those in the control. TPA treatment for 4 h had no effect on total [ 3 H]hypoxanthine incorporation or incorporation into acid-soluble and acid-insoluble fractions. Thus, the effect of TPA on metabolic cooperation is interpreted as a reduction in the transfer of [ 3 H]nucleotides and is an indication of an interference with intercellular communication

  9. Recent developments in our understanding of the implications of traditional African medicine on drug metabolism.

    Science.gov (United States)

    Gouws, Chrisna; Hamman, Josias H

    2018-02-01

    The use of traditional herbal medicines has become increasingly popular globally, but in some countries, it is the main or sometimes even the only healthcare service available in the most rural areas. This is especially true for Africa where herbal medicines form a key component of traditional medicinal practices and there is access to a diversity of medicinal plants. Although many benefits have been derived from the use of traditional herbal medicines, many concerns are associated with their use of which herb-drug interactions have been identified to have a rising impact on patient treatment outcome. One type of pharmacokinetic interaction involves the modulation of drug metabolizing enzymes, which may result in enhanced or reduced bioavailability of co-administered drugs. Areas covered: This review highlights the current information available on drug metabolism-associated information with regards to traditional African medicines related to some of the most prevalent diseases burdening the African continent. Expert opinion: It is clear from previous studies that enzyme modulation by traditional African medicines plays a significant role in the pharmacokinetics of some co-administered drugs, but more research is needed to provide detailed information on these interactions, specifically for treatment of prevalent diseases such as tuberculosis and hypertension.

  10. Stable Overexpression of the Constitutive Androstane Receptor Reduces the Requirement for Culture with Dimethyl Sulfoxide for High Drug Metabolism in HepaRG Cells.

    Science.gov (United States)

    van der Mark, Vincent A; Rudi de Waart, D; Shevchenko, Valery; Elferink, Ronald P J Oude; Chamuleau, Robert A F M; Hoekstra, Ruurdtje

    2017-01-01

    Dimethylsulfoxide (DMSO) induces cellular differentiation and expression of drug metabolic enzymes in the human liver cell line HepaRG; however, DMSO also induces cell death and interferes with cellular activities. The aim of this study was to examine whether overexpression of the constitutive androstane receptor (CAR, NR1I3), the nuclear receptor controlling various drug metabolism genes, would sufficiently promote differentiation and drug metabolism in HepaRG cells, optionally without using DMSO. By stable lentiviral overexpression of CAR, HepaRG cultures were less affected by DMSO in total protein content and obtained increased resistance to acetaminophen- and amiodarone-induced cell death. Transcript levels of CAR target genes were significantly increased in HepaRG-CAR cultures without DMSO, resulting in increased activities of cytochrome P450 (P450) enzymes and bilirubin conjugation to levels equal or surpassing those of HepaRG cells cultured with DMSO. Unexpectedly, CAR overexpression also increased the activities of non-CAR target P450s, as well as albumin production. In combination with DMSO treatment, CAR overexpression further increased transcript levels and activities of CAR targets. Induction of CYP1A2 and CYP2B6 remained unchanged, whereas CYP3A4 was reduced. Moreover, the metabolism of low-clearance compounds warfarin and prednisolone was increased. In conclusion, CAR overexpression creates a more physiologically relevant environment for studies on hepatic (drug) metabolism and differentiation in HepaRG cells without the utilization of DMSO. DMSO still may be applied to accomplish higher drug metabolism, required for sensitive assays, such as low-clearance studies and identification of (rare) metabolites, whereas reduced total protein content after DMSO culture is diminished by CAR overexpression. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  11. Computer modelling of HT gas metabolism in humans

    International Nuclear Information System (INIS)

    Peterman, B.F.

    1982-01-01

    A mathematical model was developed to simulate the metabolism of HT gas in humans. The rate constants of the model were estimated by fitting the calculated curves to the experimental data by Pinson and Langham in 1957. The calculations suggest that the oxidation of HT gas (which probably occurs as a result of the enzymatic action of hydrogenase present in bacteria of human gut) occurs at a relatively low rate with a half-time of 10-12 hours. The inclusion of the dose due to the production of the HT oxidation product (HTO) in the soft tissues lowers the value of derived air concentration by about 50%. Furthermore the relationship between the concentration of HTO in urine and the dose to the lung from HT in the air in lungs is linear after short HT exposures, and hence HTO concentrations in urine can be used to estimate the upper limits on the lung dose from HT exposures. (author)

  12. Metabolism of dimethylnitrosamine and 1,2-dimethylhydrazine in cultured human bronchi

    DEFF Research Database (Denmark)

    Harris, Curtis C.; Autrup, Herman; Stoner, Gary D.

    1977-01-01

    The metabolic activation of several chemical classes of procarcinogens is being studied in cultured human bronchi. Previous studies have shown that carcinogenic polynuclear aromatic hydrocarbons are metabolically activated by the bronchial epithelium. In the study reported here, dimethylnitrosami...

  13. Metabolic network analysis-based identification of antimicrobial drug targets in category A bioterrorism agents.

    Directory of Open Access Journals (Sweden)

    Yong-Yeol Ahn

    Full Text Available The 2001 anthrax mail attacks in the United States demonstrated the potential threat of bioterrorism, hence driving the need to develop sophisticated treatment and diagnostic protocols to counter biological warfare. Here, by performing flux balance analyses on the fully-annotated metabolic networks of multiple, whole genome-sequenced bacterial strains, we have identified a large number of metabolic enzymes as potential drug targets for each of the three Category A-designated bioterrorism agents including Bacillus anthracis, Francisella tularensis and Yersinia pestis. Nine metabolic enzymes- belonging to the coenzyme A, folate, phosphatidyl-ethanolamine and nucleic acid pathways common to all strains across the three distinct genera were identified as targets. Antimicrobial agents against some of these enzymes are available. Thus, a combination of cross species-specific antibiotics and common antimicrobials against shared targets may represent a useful combinatorial therapeutic approach against all Category A bioterrorism agents.

  14. Effects of Radiation and Dietary Iron on Expression of Genes and Proteins Involved in Drug Metabolism

    Science.gov (United States)

    Faust, K. M.; Wotring, V. E.

    2014-01-01

    Liver function, especially the rate of metabolic enzyme activities, determines the concentration of circulating drugs and the duration of their efficacy. Most pharmaceuticals are metabolized by the liver, and clinically-used medication doses are given with normal liver function in mind. A drug overdose can result in the case of a liver that is damaged and removing pharmaceuticals from the circulation at a rate slower than normal. Alternatively, if liver function is elevated and removing drugs from the system more quickly than usual, it would be as if too little drug had been given for effective treatment. Because of the importance of the liver in drug metabolism, we want to understand any effects of spaceflight on the enzymes of the liver. Dietary factors and exposure to radiation are aspects of spaceflight that are potential oxidative stressors and both can be modeled in ground experiments. In this experiment, we examined the effects of high dietary iron and low dose gamma radiation (individually and combined) on the gene expression of enzymes involved in drug metabolism, redox homeostasis, and DNA repair. METHODS All procedures were approved by the JSC Animal Care and Use Committee. Male Sprague-Dawley rats were divided into 4 groups (n=8); control, high Fe diet (650 mg iron/kg), radiation (fractionated 3 Gy exposure from a Cs- 137 source) and combined high Fe diet + radiation exposure. Animals were euthanized 24h after the last treatment of radiation; livers were removed immediately and flash -frozen in liquid nitrogen. Expression of genes thought to be involved in redox homeostasis, drug metabolism and DNA damage repair was measured by RT-qPCR. Where possible, protein expression of the same genes was measured by western blotting. All data are expressed as % change in expression normalized to reference gene expression; comparisons were then made of each treatment group to the sham exposed/ normal diet control group. Data was considered significant at phigh Fe

  15. "Not for human consumption": a review of emerging designer drugs.

    Science.gov (United States)

    Musselman, Megan E; Hampton, Jeremy P

    2014-07-01

    Synthetic, or "designer" drugs, are created by manipulating the chemical structures of other psychoactive drugs so that the resulting product is structurally similar but not identical to illegal psychoactive drugs. Originally developed in the 1960s as a way to evade existing drug laws, the use of designer drugs has increased dramatically over the past few years. These drugs are deceptively packaged as "research chemicals," "incense," "bath salts," or "plant food," among other names, with labels that may contain warnings such as "not for human consumption" or "not for sale to minors." The clinical effects of most new designer drugs can be described as either hallucinogenic, stimulant, or opioid-like. They may also have a combination of these effects due to designer side-chain substitutions. The easy accessibility and rapid emergence of new designer drugs have created challenges for health care providers when treating patients presenting with acute toxicity from these substances, many of which can produce significant and/or life-threatening adverse effects. Moreover, the health care provider has no way to verify the contents and/or potency of the agent ingested because it can vary between packages and distributors. Therefore, a thorough knowledge of the available designer drugs, common signs and symptoms of toxicity associated with these agents, and potential effective treatment modalities are essential to appropriately manage these patients. © 2014 Pharmacotherapy Publications, Inc.

  16. Recent advances in fluorination techniques and their anticipated impact on drug metabolism and toxicity

    OpenAIRE

    Murphy, Cormac D.; Sandford, Graham

    2015-01-01

    Introduction: Fluorine’s unique physicochemical properties make it a key element for incorporation into pharmacologically active compounds. Its presence in a drug can alter a number of characteristics that affect ADME-Tox, which has prompted efforts at improving synthetic fluorination procedures. Areas covered: This review describes the influence of fluorine on attributes such as potency, lipophilicity, metabolic stability and bioavailablility and how the effects observed are related to the p...

  17. Endocrine and Metabolic Adverse Effects of Psychotropic Drugs in Children and Adolescents

    Directory of Open Access Journals (Sweden)

    Evrim Aktepe

    2011-12-01

    Full Text Available ABSTRACT Much as an increase in the use of psychotropic drugs is observed in children and adolescents over the last decade, the endocrine and metabolic side effects of these drugs can limit their use. Atypical antipsychotics can cause many side effects, which are not suitable for the developmental periods of children and adolescents, such as those related with thyroid, blood sugar, level of sex hormones, growth rate and bone metabolism. Children are under a more serious risk regarding the weight increasing effects of atypical antipsychotics and weight gain that is not proportionate with age is especially important due to the association between glucose or lipid abnormalities and cardiovascular mortality. Aripiprazole and ziprasidone are the least risky antipsychotic drugs when it comes to metabolic side affects. The antipsychotic drug that is associated with weight increase and diabetes in children and adolescents most is olanzapine. Even though there are no comparative long-term data concerning children, it is suggested by the currently available information that metabolic side effects including dyslipidemia and impaired glucose tolerance are at an alarming level when it comes to long-term treatment with antipsychotics. The most risky agents in terms of hyperglycemia and glucosuria development are olanzapine and clozapine. Use of risperidone and haloperidol should be undertaken with caution since it may bring about the risk of hyperprolactinemia. Among the antidepressants associated with weight loss and suppression of appetite are selective serotonin reuptake inhibitors, bupropion and venlafaxine. Thyroid functions can be affected by lithium, carbamazepine and valproate treatments. It is reported that the side effect most frequently associated with valproate is weight increase. The relationship between valproate treatment and the development of hyperandrogenism and polycystic ovary syndrome in young women should also be kept in mind. [TAF Prev

  18. Electrochemistry in the mimicry of oxidative drug metabolism by cytochrome P450s.

    Science.gov (United States)

    Nouri-Nigjeh, Eslam; Bischoff, Rainer; Bruins, Andries P; Permentier, Hjalmar P

    2011-05-01

    Prediction of oxidative drug metabolism at the early stages of drug discovery and development requires fast and accurate analytical techniques to mimic the in vivo oxidation reactions by cytochrome P450s (CYP). Direct electrochemical oxidation combined with mass spectrometry, although limited to the oxidation reactions initiated by charge transfer, has shown promise in the mimicry of certain CYP-mediated metabolic reactions. The electrochemical approach may further be utilized in an automated manner in microfluidics devices facilitating fast screening of oxidative drug metabolism. A wide range of in vivo oxidation reactions, particularly those initiated by hydrogen atom transfer, can be imitated through the electrochemically-assisted Fenton reaction. This reaction is based on O-O bond activation in hydrogen peroxide and oxidation by hydroxyl radicals, wherein electrochemistry is used for the reduction of molecular oxygen to hydrogen peroxide, as well as the reduction of Fe(3+) to Fe(2+). Metalloporphyrins, as surrogates for the prosthetic group in CYP, utilizing metallo-oxo reactive species, can also be used in combination with electrochemistry. Electrochemical reduction of metalloporphyrins in solution or immobilized on the electrode surface activates molecular oxygen in a manner analogous to the catalytical cycle of CYP and different metalloporphyrins can mimic selective oxidation reactions. Chemoselective, stereoselective, and regioselective oxidation reactions may be mimicked using electrodes that have been modified with immobilized enzymes, especially CYP itself. This review summarizes the recent attempts in utilizing electrochemistry as a versatile analytical and preparative technique in the mimicry of oxidative drug metabolism by CYP. © 2011 Bentham Science Publishers Ltd.

  19. Norepinephrine metabolism in humans. Kinetic analysis and model

    International Nuclear Information System (INIS)

    Linares, O.A.; Jacquez, J.A.; Zech, L.A.; Smith, M.J.; Sanfield, J.A.; Morrow, L.A.; Rosen, S.G.; Halter, J.B.

    1987-01-01

    The present study was undertaken to quantify more precisely and to begin to address the problem of heterogeneity of the kinetics of distribution and metabolism of norepinephrine (NE) in humans, by using compartmental analysis. Steady-state NE specific activity in arterialized plasma during [ 3 H]NE infusion and postinfusion plasma disappearance of [ 3 H]NE were measured in eight healthy subjects in the supine and upright positions. Two exponentials were clearly identified in the plasma [ 3 H]NE disappearance curves of each subject studied in the supine (r = 0.94-1.00, all P less than 0.01) and upright (r = 0.90-0.98, all P less than 0.01) positions. A two-compartment model was the minimal model necessary to simultaneously describe the kinetics of NE in the supine and upright positions. The NE input rate into the extravascular compartment 2, estimated with the minimal model, increased with upright posture (1.87 +/- 0.08 vs. 3.25 +/- 0.2 micrograms/min per m2, P less than 0.001). Upright posture was associated with a fall in the volume of distribution of NE in compartment 1 (7.5 +/- 0.6 vs. 4.7 +/- 0.3 liters, P less than 0.001), and as a result of that, there was a fall in the metabolic clearance rate of NE from compartment 1 (1.80 +/- 0.11 vs. 1.21 +/- 0.08 liters/min per m2, P less than 0.001). We conclude that a two-compartment model is the minimal model that can accurately describe the kinetics of distribution and metabolism of NE in humans

  20. Effect of Methamphetamine on Spectral Binding, Ligand Docking and Metabolism of Anti-HIV Drugs with CYP3A4

    Science.gov (United States)

    Ande, Anusha; Wang, Lei; Vaidya, Naveen K.; Li, Weihua; Kumar, Santosh; Kumar, Anil

    2016-01-01

    Cytochrome P450 3A4 (CYP3A4) is the major drug metabolic enzyme, and is involved in the metabolism of antiretroviral drugs, especially protease inhibitors (PIs). This study was undertaken to examine the effect of methamphetamine on the binding and metabolism of PIs with CYP3A4. We showed that methamphetamine exhibits a type I spectral change upon binding to CYP3A4 with δAmax and KD of 0.016±0.001 and 204±18 μM, respectively. Methamphetamine-CYP3A4 docking showed that methamphetamine binds to the heme of CYP3A4 in two modes, both leading to N-demethylation. We then studied the effect of methamphetamine binding on PIs with CYP3A4. Our results showed that methamphetamine alters spectral binding of nelfinavir but not the other type I PIs (lopinavir, atazanavir, tipranavir). The change in spectral binding for nelfinavir was observed at both δAmax (0.004±0.0003 vs. 0.0068±0.0001) and KD (1.42±0.36 vs.2.93±0.08 μM) levels. We further tested effect of methamphetamine on binding of 2 type II PIs; ritonavir and indinavir. Our results showed that methamphetamine alters the ritonavir binding to CYP3A4 by decreasing both the δAmax (0.0038±0.0003 vs. 0.0055±0.0003) and KD (0.043±0.0001 vs. 0.065±0.001 nM), while indinavir showed only reduced KD in presence of methamphetamine (0.086±0.01 vs. 0.174±0.03 nM). Furthermore, LC-MS/MS studies in high CYP3A4 human liver microsomes showed a decrease in the formation of hydroxy ritonavir in the presence of methamphetamine. Finally, CYP3A4 docking with lopinavir and ritonavir in the absence and presence of methamphetamine showed that methamphetamine alters the docking of ritonavir, which is consistent with the results obtained from spectral binding and metabolism studies. Overall, our results demonstrated differential effects of methamphetamine on the binding and metabolism of PIs with CYP3A4. These findings have clinical implication in terms of drug dose adjustment of antiretroviral medication, especially with ritonavir

  1. The thalamus in drug addiction: from rodents to humans.

    Science.gov (United States)

    Huang, Anna S; Mitchell, Jameson A; Haber, Suzanne N; Alia-Klein, Nelly; Goldstein, Rita Z

    2018-03-19

    Impairments in response inhibition and salience attribution (iRISA) have been proposed to underlie the clinical symptoms of drug addiction as mediated by cortico-striatal-thalamo-cortical networks. The bulk of evidence supporting the iRISA model comes from neuroimaging research that has focused on cortical and striatal influences with less emphasis on the role of the thalamus. Here, we highlight the importance of the thalamus in drug addiction, focusing on animal literature findings on thalamic nuclei in the context of drug-seeking, structural and functional changes of the thalamus as measured by imaging studies in human drug addiction, particularly during drug cue and non-drug reward processing, and response inhibition tasks. Findings from the animal literature suggest that the paraventricular nucleus of the thalamus, the lateral habenula and the mediodorsal nucleus may be involved in the reinstatement, extinction and expression of drug-seeking behaviours. In support of the iRISA model, the human addiction imaging literature demonstrates enhanced thalamus activation when reacting to drug cues and reduced thalamus activation during response inhibition. This pattern of response was further associated with the severity of, and relapse in, drug addiction. Future animal studies could widen their field of focus by investigating the specific role(s) of different thalamic nuclei in different phases of the addiction cycle. Similarly, future human imaging studies should aim to specifically delineate the structure and function of different thalamic nuclei, for example, through the application of advanced imaging protocols at higher magnetic fields (7 Tesla).This article is part of a discussion meeting issue 'Of mice and mental health: facilitating dialogue between basic and clinical neuroscientists'. © 2018 The Author(s).

  2. 3'-Azido-3'-deoxythymidine (AZT) induces apoptosis and alters metabolic enzyme activity in human placenta

    International Nuclear Information System (INIS)

    Collier, Abby C.; Helliwell, Rachel J.A.; Keelan, Jeffrey A.; Paxton, James W.; Mitchell, Murray D.; Tingle, Malcolm D.

    2003-01-01

    The anti-HIV drug 3'-azido-3'-deoxythymidine (AZT) is the drug of choice for preventing maternal-fetal HIV transmission during pregnancy. Our aim was to assess the cytotoxic effects of AZT on human placenta in vitro. The mechanisms of AZT-induced effects were investigated using JEG-3 choriocarcinoma cells and primary explant cultures from term and first-trimester human placentas. Cytotoxicity measures included trypan blue exclusion, MTT, and reactive oxygen species (ROS) assays. Apoptosis was measured with an antibody specific to cleaved caspase-3 and by rescue of cells by the general caspase inhibitor Boc-D-FMK. The effect of AZT on the activities of glutathione-S-transferase, β-glucuronidase, UDP-glucuronosyl transferase, cytochrome P450 (CYP) 1A, and CYP reductase (CYPR) in the placenta was assessed using biochemical assays and immunoblotting. AZT increased ROS levels, decreased cellular proliferation rates, was toxic to mitochondria, and initiated cell death by a caspase-dependent mechanism in the human placenta in vitro. In the absence of serum, the effects of AZT were amplified in all the models used. AZT also increased the amounts of activity of GST, β-glucuronidase, and CYP1A, whereas UGT and CYPR were decreased. We conclude that AZT causes apoptosis in the placenta and alters metabolizing enzymes in human placental cells. These findings have implications for the safe administration of AZT in pregnancy with respect to the maintenance of integrity of the maternal-fetal barrier

  3. Interaction of amphiphilic drugs with human and bovine serum albumins.

    Science.gov (United States)

    Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd Sajid; Khan, Rizwan Hasan; Kabir-Ud-Din

    2012-11-01

    To know the interaction of amphiphilic drugs nortriptyline hydrochloride (NOT) and promazine hydrochloride (PMZ) with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), techniques of UV-visible, fluorescence, and circular dichroism (CD) spectroscopies are used. The binding affinity is more in case of PMZ with both the serum albumins. The quenching rate constant (k(q)) values suggest a static quenching process for all the drug-serum albumin interactions. The UV-visible results show that the change in protein conformation of PMZ-serum albumin interactions are more prominent as compared to NOT-serum albumin interactions. The CD results also explain the conformational changes in the serum albumins on binding with the drugs. The increment in %α-helical structure is slightly more for drug-BSA complexes as compared to drug-HSA complexes. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. 76 FR 11790 - Drugs for Human Use; Drug Efficacy Study Implementation; Oral Prescription Drugs Offered for...

    Science.gov (United States)

    2011-03-03

    ... subject of an approved new drug application (NDA) or abbreviated new drug application (ANDA) (other than... 23, 1983, notice, the manufacturer had submitted supplemental applications proposing to reformulate... Laboratories, a subsidiary of Elan Corp., PLC, 800 Gateway Blvd., South San Francisco, CA 94080; Copley...

  5. Age-Related Inducibility of Carboxylesterases by the Antiepileptic Agent Phenobarbital and Implications in Drug Metabolism and Lipid Accumulation 1, 2

    Science.gov (United States)

    Xiao, Da; Chen, Yi-Tzai; Yang, Dongfang; Yan, Bingfang

    2014-01-01

    Carboxylesterases (CES) constitute a class of hydrolytic enzymes that play critical roles in drug metabolism and lipid mobilization. Previous studies with a large number of human liver samples have suggested that the inducibility of carboxylesterases is inversely related with age. To directly test this possibility, neonatal (10 days of age) and adult mice were treated with the antiepileptic agent phenobarbital. The expression and hydrolytic activity were determined on six major carboxylesterases including ces1d, the ortholog of human CES1. Without exception, all carboxylesterases tested were induced to a greater extent in neonatal than adult mice. The induction was detected at mRNA, protein and catalytic levels. Ces1d was greatly induced and found to rapidly hydrolyze the antiplatelet agent clopidogrel and support the accumulation of neutral lipids. Phenobarbital represents a large number of therapeutic agents that induce drug metabolizing enzymes and transporters in a species-conserved manner. The higher inducibility of carboxylesterases in the developmental age likely represents a general phenomenon cross species including human. Consequently, individuals in the developmental age may experience greater drug-drug interactions. The greater induction of ces1d also provides a molecular explanation to the clinical observation that children on antiepileptic drugs increase plasma lipids. PMID:22513142

  6. Drug delivery to the human brain via the cerebrospinal fluid

    Energy Technology Data Exchange (ETDEWEB)

    Howden, L.; Aroussi, A. [Univ. of Nottingham, School of Mechanical, Material, Manufacturing Engineering and Managements, Nottingham (United Kingdom)]. E-mail: eaxljh@nottingham.ac.uk; Vloeberghs, M. [Queens Medical Centre, Dept. of Child Health, Nottingham (United Kingdom)

    2003-07-01

    This Study investigates the flow of Cerebrospinal Fluid (CSF) inside the human ventricular system with particular emphasis on drug path flow for the purpose of medical drug injections. The investigation is conducted using the computational fluid dynamics package FLUENT. The role of the ventricular system is very important in protecting the brain from injury by cushioning it against the cranium during sudden movements. If for any reason the passage of CSF through the ventricular system is blocked (usually by stenosis) then a condition known as Hydrocephalus occurs, where by the blocked CSF causes the Intra Cranial Pressure (ICP) inside the brain to rise. If this is not treated then severe brain damage and death can occur. Previous work conducted by the authors on this subject has focused on the technique of ventriculostomy to treat hydrocephalus. The present study carries on from the previous work but focuses on delivering medical drugs to treat brain tumors that are conventionally not accessible and which require complicated surgical procedures to remove them. The study focuses on the possible paths for delivering drugs to tumors in the human nervous system through conventionally accessible locations without major surgery. The results of the investigation have shown that it is possible to reach over 95% of the ventricular system by injection of drugs however the results also show that there are many factors that can affect the drug flow paths through the ventricular system and thus the areas reachable, by these drugs. (author)

  7. Drug delivery to the human brain via the cerebrospinal fluid

    International Nuclear Information System (INIS)

    Howden, L.; Aroussi, A.; Vloeberghs, M.

    2003-01-01

    This Study investigates the flow of Cerebrospinal Fluid (CSF) inside the human ventricular system with particular emphasis on drug path flow for the purpose of medical drug injections. The investigation is conducted using the computational fluid dynamics package FLUENT. The role of the ventricular system is very important in protecting the brain from injury by cushioning it against the cranium during sudden movements. If for any reason the passage of CSF through the ventricular system is blocked (usually by stenosis) then a condition known as Hydrocephalus occurs, where by the blocked CSF causes the Intra Cranial Pressure (ICP) inside the brain to rise. If this is not treated then severe brain damage and death can occur. Previous work conducted by the authors on this subject has focused on the technique of ventriculostomy to treat hydrocephalus. The present study carries on from the previous work but focuses on delivering medical drugs to treat brain tumors that are conventionally not accessible and which require complicated surgical procedures to remove them. The study focuses on the possible paths for delivering drugs to tumors in the human nervous system through conventionally accessible locations without major surgery. The results of the investigation have shown that it is possible to reach over 95% of the ventricular system by injection of drugs however the results also show that there are many factors that can affect the drug flow paths through the ventricular system and thus the areas reachable, by these drugs. (author)

  8. The effects of drugs on human models of emotional processing: an account of antidepressant drug treatment.

    Science.gov (United States)

    Pringle, Abbie; Harmer, Catherine J

    2015-12-01

    Human models of emotional processing suggest that the direct effect of successful antidepressant drug treatment may be to modify biases in the processing of emotional information. Negative biases in emotional processing are documented in depression, and single or short-term dosing with conventional antidepressant drugs reverses these biases in depressed patients prior to any subjective change in mood. Antidepressant drug treatments also modulate emotional processing in healthy volunteers, which allows the consideration of the psychological effects of these drugs without the confound of changes in mood. As such, human models of emotional processing may prove to be useful for testing the efficacy of novel treatments and for matching treatments to individual patients or subgroups of patients.

  9. Human abuse liability evaluation of CNS stimulant drugs.

    Science.gov (United States)

    Romach, Myroslava K; Schoedel, Kerri A; Sellers, Edward M

    2014-12-01

    Psychoactive drugs that increase alertness, attention and concentration and energy, while also elevating mood, heart rate and blood pressure are referred to as stimulants. Despite some overlapping similarities, stimulants cannot be easily categorized by their chemical structure, mechanism of action, receptor binding profile, effects on monoamine uptake, behavioral pharmacology (e.g., effects on locomotion, temperature, and blood pressure), therapeutic indication or efficacy. Because of their abuse liability, a pre-market assessment of abuse potential is required for drugs that show stimulant properties; this review article focuses on the clinical aspects of this evaluation. This includes clinical trial adverse events, evidence of diversion or tampering, overdoses and the results of a human abuse potential study. While there are different types of human experimental studies that can be employed to evaluate stimulant abuse potential (e.g., drug discrimination, self-administration), only the human abuse potential study and clinical trial adverse event data are required for drug approval. The principal advances that have improved human abuse potential studies include using study enrichment strategies (pharmacologic qualification), larger sample sizes, better selection of endpoints and measurement strategies and more carefully considered interpretation of data. Because of the methodological advances, comparisons of newer studies with historical data is problematic and may contribute to a biased regulatory framework for the evaluation of newer stimulant-like drugs, such as A2 antagonists. This article is part of the Special Issue entitled 'CNS Stimulants'. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Metabolism of aspartame by human and pig intestinal microvillar peptidases.

    Science.gov (United States)

    Hooper, N M; Hesp, R J; Tieku, S

    1994-01-01

    The artificial sweetener aspartame (N-L-alpha-aspartyl-L-phenyl-alanine-1-methyl ester; Nutrasweet), its decomposition product alpha Asp-Phe and the related peptide alpha Asp-PheNH2 were rapidly hydrolysed by microvillar membranes prepared from human duodenum, jejunum and ileum, and from pig duodenum and kidney. The metabolism of aspartame by the human and pig intestinal microvillar membrane preparations was inhibited significantly (> 78%) by amastatin or 1,10-phenanthroline, and partially (> 38%) by actinonin or bestatin, and was activated 2.9-4.5-fold by CaCl2. The inhibition by amastatin and 1,10-phenanthroline, and the activation by CaCl2 are characteristic of the cell-surface ectoenzyme aminopeptidase A (EC 3.4.11.7) and a purified preparation of this enzyme hydrolysed aspartame with a Km of 0.25 mM and a Vmax of 126 mumol/min per mg. A purified preparation of aminopeptidase W (EC 3.4.11.16) also hydrolysed aspartame but with a Km of 4.96 mM and a Vmax of 110 mumol/min per mg. However, rentiapril, an inhibitor of aminopeptidase W, caused only slight inhibition (maximally 19%) of the hydrolysis of aspartame by the microvillar membrane preparations. Similar patterns of inhibition and kinetic parameters were observed for alpha Asp-Phe and alpha Asp-PheNH2. Two other decomposition products of aspartame, beta Asp-PheMe and cyclo-Asp-Phe, were essentially resistant to hydrolysis by both the human and pig intestinal microvillar membrane preparations and the purified preparations of aminopeptidases A and W. Although the relatively selective inhibitor of aminopeptidase N (EC 3.4.11.2), actinonin, partially inhibited the metabolism of aspartame, alpha Asp-Phe and alpha Asp-PheNH2 by the human and pig intestinal microvillar membrane preparations, these peptides were not hydrolysed by a purified preparation of aminopeptidase N. Membrane dipeptidase (EC 3.4.13.19) only hydrolysed the unblocked dipeptide, alpha Asp-Phe, but the selective inhibitor of this enzyme, cilastatin

  11. Xenobiotica-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models.

    Science.gov (United States)

    Oesch, F; Fabian, E; Landsiedel, Robert

    2018-06-18

    Studies on the metabolic fate of medical drugs, skin care products, cosmetics and other chemicals intentionally or accidently applied to the human skin have become increasingly important in order to ascertain pharmacological effectiveness and to avoid toxicities. The use of freshly excised human skin for experimental investigations meets with ethical and practical limitations. Hence information on xenobiotic-metabolizing enzymes (XME) in the experimental systems available for pertinent studies compared with native human skin has become crucial. This review collects available information of which-taken with great caution because of the still very limited data-the most salient points are: in the skin of all animal species and skin-derived in vitro systems considered in this review cytochrome P450 (CYP)-dependent monooxygenase activities (largely responsible for initiating xenobiotica metabolism in the organ which provides most of the xenobiotica metabolism of the mammalian organism, the liver) are very low to undetectable. Quite likely other oxidative enzymes [e.g. flavin monooxygenase, COX (cooxidation by prostaglandin synthase)] will turn out to be much more important for the oxidative xenobiotic metabolism in the skin. Moreover, conjugating enzyme activities such as glutathione transferases and glucuronosyltransferases are much higher than the oxidative CYP activities. Since these conjugating enzymes are predominantly detoxifying, the skin appears to be predominantly protected against CYP-generated reactive metabolites. The following recommendations for the use of experimental animal species or human skin in vitro models may tentatively be derived from the information available to date: for dermal absorption and for skin irritation esterase activity is of special importance which in pig skin, some human cell lines and reconstructed skin models appears reasonably close to native human skin. With respect to genotoxicity and sensitization reactive

  12. 21 CFR 14.160 - Establishment of standing technical advisory committees for human prescription drugs.

    Science.gov (United States)

    2010-04-01

    ... and advertising, and regulatory control of the human prescription drugs falling within the... continued approval for marketing; or (3) A particular drug is properly classified as a new drug, an old drug...

  13. Metabolism of 123I-FP-CIT in humans

    International Nuclear Information System (INIS)

    Tanaka, Akihiro; Okano, Kyoko; Tamagami, Hiroshi

    1999-01-01

    The metabolism of N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl)nortropane ( 123 I) ( 123 I-FP-CIT) in healthy humans was studied. Plasma and urine samples, obtained after i.v. administration of 123 I-FP-CIT, were analyzed using the two-dimensional thin-layer chromatography technique. Eleven radiochemical components were detected in both plasma and urine, and four of them were the parent 123 I-FP-CIT and its metabolites, N-(3-fluoropropyl)-2β-carboxy-3β-(4-iodophenyl)nortropane ( 123 I) ( 123 I-acid), 2β-carboxy-3β-(4-iodophenyl)nortropane ( 123 I) ( 123 I-nor-acid) and 2β-carbomethoxy-3β-(4-iodophenyl)nortropane ( 123 I) ( 123 I-nor-CIT). These four identified radiochemical components occupied about 80% or more in ratio of the radiochemical components in the plasma and urine. In the metabolites of 123 I-FP-CIT, the high polar metabolites- 123 I-acid and 123 I-nor-acid-were found to be the major components, while lipophilic 123 I-nor-CIT was a minor component. Free iodide ( 123 I - ) was not found in the plasma or urine. Thus, the main metabolic reactions which 123 I-FP-CIT undergoes in humans seem to be hydrolysis of the ester bond and N-dealkylation. In vivo deiodination of 123 I-FP-CIT was found to be minimum. Current results suggest that the metabolites of 123 I-FP-CIT hardly influence evaluation of the dopamine transporter in the human brain. (author)

  14. 3D Miniaturization of Human Organs for Drug Discovery.

    Science.gov (United States)

    Park, Joseph; Wetzel, Isaac; Dréau, Didier; Cho, Hansang

    2018-01-01

    "Engineered human organs" hold promises for predicting the effectiveness and accuracy of drug responses while reducing cost, time, and failure rates in clinical trials. Multiorgan human models utilize many aspects of currently available technologies including self-organized spherical 3D human organoids, microfabricated 3D human organ chips, and 3D bioprinted human organ constructs to mimic key structural and functional properties of human organs. They enable precise control of multicellular activities, extracellular matrix (ECM) compositions, spatial distributions of cells, architectural organizations of ECM, and environmental cues. Thus, engineered human organs can provide the microstructures and biological functions of target organs and advantageously substitute multiscaled drug-testing platforms including the current in vitro molecular assays, cell platforms, and in vivo models. This review provides an overview of advanced innovative designs based on the three main technologies used for organ construction leading to single and multiorgan systems useable for drug development. Current technological challenges and future perspectives are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A high content screening assay to predict human drug-induced liver injury during drug discovery.

    Science.gov (United States)

    Persson, Mikael; Løye, Anni F; Mow, Tomas; Hornberg, Jorrit J

    2013-01-01

    Adverse drug reactions are a major cause for failures of drug development programs, drug withdrawals and use restrictions. Early hazard identification and diligent risk avoidance strategies are therefore essential. For drug-induced liver injury (DILI), this is difficult using conventional safety testing. To reduce the risk for DILI, drug candidates with a high risk need to be identified and deselected. And, to produce drug candidates without that risk associated, risk factors need to be assessed early during drug discovery, such that lead series can be optimized on safety parameters. This requires methods that allow for medium-to-high throughput compound profiling and that generate quantitative results suitable to establish structure-activity-relationships during lead optimization programs. We present the validation of such a method, a novel high content screening assay based on six parameters (nuclei counts, nuclear area, plasma membrane integrity, lysosomal activity, mitochondrial membrane potential (MMP), and mitochondrial area) using ~100 drugs of which the clinical hepatotoxicity profile is known. We find that a 100-fold TI between the lowest toxic concentration and the therapeutic Cmax is optimal to classify compounds as hepatotoxic or non-hepatotoxic, based on the individual parameters. Most parameters have ~50% sensitivity and ~90% specificity. Drugs hitting ≥2 parameters at a concentration below 100-fold their Cmax are typically hepatotoxic, whereas non-hepatotoxic drugs typically hit based on nuclei count, MMP and human Cmax, we identified an area without a single false positive, while maintaining 45% sensitivity. Hierarchical clustering using the multi-parametric dataset roughly separates toxic from non-toxic compounds. We employ the assay in discovery projects to prioritize novel compound series during hit-to-lead, to steer away from a DILI risk during lead optimization, for risk assessment towards candidate selection and to provide guidance of safe

  16. Failure of Chemotherapy in Hepatocellular Carcinoma Due to Impaired and Dysregulated Primary Liver Drug Metabolizing Enzymes and Drug Transport Proteins: What to Do?

    Science.gov (United States)

    Ul Islam, Salman; Ahmed, Muhammad Bilal; Shehzad, Adeeb; Ul-Islam, Mazhar; Lee, Young Sup

    2018-05-28

    Most of the drugs are metabolized in the liver by the action of drug metabolizing enzymes. In hepatocellular carcinoma (HCC), primary drug metabolizing enzymes are severely dysregulated, leading to failure of chemotherapy. Sorafenib is the only standard systemic drug available, but it still presents certain limitations, and much effort is required to understand who is responsive and who is refractory to the drug. Preventive and therapeutic approaches other than systemic chemotherapy include vaccination, chemoprevention, liver transplantation, surgical resection, and locoregional therapies. This review details the dysregulation of primary drug metabolizing enzymes and drug transport proteins of the liver in HCC and their influence on chemotherapeutic drugs. Furthermore, it emphasizes the adoption of safe alternative therapeutic strategies to chemotherapy. The future of HCC treatment should emphasize the understanding of resistance mechanisms and the finding of novel, safe, and efficacious therapeutic strategies, which will surely benefit patients affected by advanced HCC. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. The current state of GPCR-based drug discovery to treat metabolic disease.

    Science.gov (United States)

    Sloop, Kyle W; Emmerson, Paul J; Statnick, Michael A; Willard, Francis S

    2018-02-02

    One approach of modern drug discovery is to identify agents that enhance or diminish signal transduction cascades in various cell types and tissues by modulating the activity of GPCRs. This strategy has resulted in the development of new medicines to treat many conditions, including cardiovascular disease, psychiatric disorders, HIV/AIDS, certain forms of cancer and Type 2 diabetes mellitus (T2DM). These successes justify further pursuit of GPCRs as disease targets and provide key learning that should help guide identifying future therapeutic agents. This report reviews the current landscape of GPCR drug discovery with emphasis on efforts aimed at developing new molecules for treating T2DM and obesity. We analyse historical efforts to generate GPCR-based drugs to treat metabolic disease in terms of causal factors leading to success and failure in this endeavour. © 2018 The British Pharmacological Society.

  18. Pharmacogenetic landscape of Metabolic Syndrome components drug response in Tunisia and comparison with worldwide populations.

    Science.gov (United States)

    Jmel, Haifa; Romdhane, Lilia; Ben Halima, Yosra; Hechmi, Meriem; Naouali, Chokri; Dallali, Hamza; Hamdi, Yosr; Shan, Jingxuan; Abid, Abdelmajid; Jamoussi, Henda; Trabelsi, Sameh; Chouchane, Lotfi; Luiselli, Donata; Abdelhak, Sonia; Kefi, Rym

    2018-01-01

    Genetic variation is an important determinant affecting either drug response or susceptibility to adverse drug reactions. Several studies have highlighted the importance of ethnicity in influencing drug response variability that should be considered during drug development. Our objective is to characterize the genetic variability of some pharmacogenes involved in the response to drugs used for the treatment of Metabolic Syndrome (MetS) in Tunisia and to compare our results to the worldwide populations. A set of 135 Tunisians was genotyped using the Affymetrix Chip 6.0 genotyping array. Variants located in 24 Very Important Pharmacogenes (VIP) involved in MetS drug response were extracted from the genotyping data. Analysis of variant distribution in Tunisian population compared to 20 worldwide populations publicly available was performed using R software packages. Common variants between Tunisians and the 20 investigated populations were extracted from genotyping data. Multidimensional screening showed that Tunisian population is clustered with North African and European populations. The greatest divergence was observed with the African and Asian population. In addition, we performed Inter-ethnic comparison based on the genotype frequencies of five VIP biomarkers. The genotype frequencies of the biomarkers rs3846662, rs1045642, rs7294 and rs12255372 located respectively in HMGCR, ABCB1, VKORC1 and TCF7L2 are similar between Tunisian, Tuscan (TSI) and European (CEU). The genotype frequency of the variant rs776746 located in CYP3A5 gene is similar between Tunisian and African populations and different from CEU and TSI. The present study shows that the genetic make up of the Tunisian population is relatively complex in regard to pharmacogenes and reflects previous historical events. It is important to consider this ethnic difference in drug prescription in order to optimize drug response to avoid serious adverse drug reactions. Taking into account similarities with

  19. Pharmacogenetic landscape of Metabolic Syndrome components drug response in Tunisia and comparison with worldwide populations

    Science.gov (United States)

    Jmel, Haifa; Romdhane, Lilia; Ben Halima, Yosra; Hechmi, Meriem; Naouali, Chokri; Dallali, Hamza; Hamdi, Yosr; Shan, Jingxuan; Abid, Abdelmajid; Jamoussi, Henda; Trabelsi, Sameh; Chouchane, Lotfi; Luiselli, Donata; Abdelhak, Sonia

    2018-01-01

    Genetic variation is an important determinant affecting either drug response or susceptibility to adverse drug reactions. Several studies have highlighted the importance of ethnicity in influencing drug response variability that should be considered during drug development. Our objective is to characterize the genetic variability of some pharmacogenes involved in the response to drugs used for the treatment of Metabolic Syndrome (MetS) in Tunisia and to compare our results to the worldwide populations. A set of 135 Tunisians was genotyped using the Affymetrix Chip 6.0 genotyping array. Variants located in 24 Very Important Pharmacogenes (VIP) involved in MetS drug response were extracted from the genotyping data. Analysis of variant distribution in Tunisian population compared to 20 worldwide populations publicly available was performed using R software packages. Common variants between Tunisians and the 20 investigated populations were extracted from genotyping data. Multidimensional screening showed that Tunisian population is clustered with North African and European populations. The greatest divergence was observed with the African and Asian population. In addition, we performed Inter-ethnic comparison based on the genotype frequencies of five VIP biomarkers. The genotype frequencies of the biomarkers rs3846662, rs1045642, rs7294 and rs12255372 located respectively in HMGCR, ABCB1, VKORC1 and TCF7L2 are similar between Tunisian, Tuscan (TSI) and European (CEU). The genotype frequency of the variant rs776746 located in CYP3A5 gene is similar between Tunisian and African populations and different from CEU and TSI. The present study shows that the genetic make up of the Tunisian population is relatively complex in regard to pharmacogenes and reflects previous historical events. It is important to consider this ethnic difference in drug prescription in order to optimize drug response to avoid serious adverse drug reactions. Taking into account similarities with

  20. Correlation between oral drug absorption in humans and apparent drug permeability coefficients in human intestinal epithelial (Caco-2) cells

    International Nuclear Information System (INIS)

    Artursson, P.; Karlsson, J.

    1991-01-01

    Monolayers of a well differentiated human intestinal epithelial cell line, Caco-2, were used as a model to study passive drug absorption across the intestinal epithelium. Absorption rate constants (expressed as apparent permeability coefficients) were determined for 20 drugs and peptides with different structural properties. The permeability coefficients ranged from approximately 5 x 10 - 8 to 5 x 10 - 5 cm/s. A good correlation was obtained between data on oral absorption in humans and the results in the Caco-2 model. Drugs that are completely absorbed in humans had permeability coefficients greater than 1 x 10 - 6 cm/s. Drugs that are absorbed to greater than 1% but less than 100% had permeability coefficients of 0.1-1.0 x 10 - 6 cm/s while drugs and peptides that are absorbed to less than 1% had permeability coefficients of less than or equal to 1 x 10 - 7 cm/s. The results indicate that Caco-2 monolayers can be used as a model for studies on intestinal drug absorption

  1. Obesity-related metabolic dysfunction in dogs: a comparison with human metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Tvarijonaviciute Asta

    2012-08-01

    Full Text Available Abstract Background Recently, metabolic syndrome (MS has gained attention in human metabolic medicine given its associations with development of type 2 diabetes mellitus and cardiovascular disease. Canine obesity is associated with the development of insulin resistance, dyslipidaemia, and mild hypertension, but the authors are not aware of any existing studies examining the existence or prevalence of MS in obese dogs. Thirty-five obese dogs were assessed before and after weight loss (median percentage loss 29%, range 10-44%. The diagnostic criteria of the International Diabetes Federation were modified in order to define canine obesity-related metabolic dysfunction (ORMD, which included a measure of adiposity (using a 9-point body condition score [BCS], systolic blood pressure, fasting plasma cholesterol, plasma triglyceride, and fasting plasma glucose. By way of comparison, total body fat mass was measured by dual-energy X-ray absorptiometry, whilst total adiponectin, fasting insulin, and high-sensitivity C-reactive protein (hsCRP were measured using validated assays. Results Systolic blood pressure (P = 0.008, cholesterol (P = 0.003, triglyceride (P = 0.018, and fasting insulin (P P = 0.001. However, hsCRP did not change with weight loss. Prior to weight loss, 7 dogs were defined as having ORMD, and there was no difference in total fat mass between these dogs and those who did not meet the criteria for ORMD. However, plasma adiponectin concentration was less (P = 0.031, and plasma insulin concentration was greater (P = 0.030 in ORMD dogs. Conclusions In this study, approximately 20% of obese dogs suffer from ORMD, and this is characterized by hypoadiponectinaemia and hyperinsulinaemia. These studies can form the basis of further investigations to determine path genetic mechanisms and the health significance for dogs, in terms of disease associations and outcomes of weight loss.

  2. Association of metabolic syndrome with atypical antipsychotic drug (olanzapine) short term versus long term use

    International Nuclear Information System (INIS)

    Ikram, H.; Ahmed, T.M.; Hayat, A.; Ullah, Q.I.; Nawaz, A.

    2017-01-01

    Objective: To determine the association of metabolic syndrome with atypical antipsychotic drug (olanzapine) short term versus long term use. Study Design: Case control study. Place and Duration of Study: Chemical pathology department Army Medical College Rawalpindi, from Nov 2014 to Oct 2015. Material and Methods: The study was carried out on 240 subjects, 120 cases and 120 controls. For the purpose of the study cases were divided into four groups A, B, C and D according to the duration of drug use. Group A patients included those who the last the drug olanzapine for the last three months. Group B patients included those who were using the drug olanzapine for the last six months. Group C and D included those who were using the drug for last 1 year and more than one year (2-5 years) respectively. By employing non probability convenience sampling technique the data was collected from patients having the diagnosis of psychosis as per DSM IV modified criteria through a proforma and fasting blood samples were drawn. These samples were tested for fasting serum lipid profile and fasting plasma glucose. The data obtained were analyzed using SPSS version 21. For quantitative data Mean and SD were calculated. For qualitative data frequency and percentages were calculated. Qualitative data was compared using chi square test whereas quantitative data was compared using independent sample t-test. Results: There was statistically no significant difference in fasting plasma glucose between group A and B and their controls whereas in group C and D these levels were significantly high as compared to controls. Triglyceride levels were significantly higher and HDL cholesterol levels were significantly lower in all four groups as compared to controls. Comparison of qualitative data which included waist circumference and blood pressure showed statistically no significant rise for group A whereas waist circumference showed insignificant rise and blood pressure showed statistically

  3. Recent advances in fluorination techniques and their anticipated impact on drug metabolism and toxicity.

    Science.gov (United States)

    Murphy, Cormac D; Sandford, Graham

    2015-04-01

    Fluorine's unique physicochemical properties make it a key element for incorporation into pharmacologically active compounds. Its presence in a drug can alter a number of characteristics that affect ADME-Tox, which has prompted efforts at improving synthetic fluorination procedures. This review describes the influence of fluorine on attributes such as potency, lipophilicity, metabolic stability and bioavailablility and how the effects observed are related to the physicochemical characteristics of the element. Examples of more recently used larger scale synthetic methods for introduction of fluorine into drug leads are detailed and the potential for using biological systems for fluorinated drug production is discussed. The synthetic procedures for carbon-fluorine bond formation largely still rely on decades-old technology for the manufacturing scale and new reagents and methods are required to meet the demands for the preparation of structurally more complex drugs. The improvement of in vitro and computational methods should make fluorinated drug design more efficient and place less emphasis on approaches such as fluorine scanning and animal studies. The introduction of new fluorinated drugs, and in particular those that have novel fluorinated functional groups, should be accompanied by rigorous environmental assessment to determine the nature of transformation products that may cause ecological damage.

  4. Putative drug and vaccine target protein identification using comparative genomic analysis of KEGG annotated metabolic pathways of Mycoplasma hyopneumoniae.

    Science.gov (United States)

    Damte, Dereje; Suh, Joo-Won; Lee, Seung-Jin; Yohannes, Sileshi Belew; Hossain, Md Akil; Park, Seung-Chun

    2013-07-01

    In the present study, a computational comparative and subtractive genomic/proteomic analysis aimed at the identification of putative therapeutic target and vaccine candidate proteins from Kyoto Encyclopedia of Genes and Genomes (KEGG) annotated metabolic pathways of Mycoplasma hyopneumoniae was performed for drug design and vaccine production pipelines against M.hyopneumoniae. The employed comparative genomic and metabolic pathway analysis with a predefined computational systemic workflow extracted a total of 41 annotated metabolic pathways from KEGG among which five were unique to M. hyopneumoniae. A total of 234 proteins were identified to be involved in these metabolic pathways. Although 125 non homologous and predicted essential proteins were found from the total that could serve as potential drug targets and vaccine candidates, additional prioritizing parameters characterize 21 proteins as vaccine candidate while druggability of each of the identified proteins evaluated by the DrugBank database prioritized 42 proteins suitable for drug targets. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Bacterial metabolism of human polymorphonuclear leukocyte-derived arachidonic acid.

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    Sorrell, T C; Muller, M; Sztelma, K

    1992-05-01

    Evidence for transcellular bacterial metabolism of phagocyte-derived arachidonic acid was sought by exposing human blood polymorphonuclear leukocytes, prelabelled with [3H]arachidonic acid, to opsonized, stationary-phase Pseudomonas aeruginosa (bacteria-to-phagocyte ratio of 50:1) for 90 min at 37 degrees C. Control leukocytes were stimulated with the calcium ionophore A23187 (5 microM) for 5 min. Radiochromatograms of arachidonic acid metabolites, extracted from A23187-stimulated cultures and then separated by reverse-phase high-performance liquid chromatography, revealed leukotriene B4, its omega-oxidation products, and 5-hydroxy-eicosatetraenoic acid. In contrast, two major metabolite peaks, distinct from known polymorphonuclear leukocyte arachidonic acid products by high-performance liquid chromatography or by thin-layer chromatography, were identified in cultures of P. aeruginosa with [3H]arachidonic acid-labelled polymorphonuclear leukocytes. Respective chromatographic characteristics of these novel products were identical to those of two major metabolite peaks produced by incubation of stationary-phase P. aeruginosa with [3H]arachidonic acid. Production of the metabolites was dependent upon pseudomonal viability. UV spectral data were consistent with a conjugated diene structure. Metabolism of arachidonic acid by P. aeruginosa was not influenced by the presence of catalase, superoxide dismutase, nordihydroguaiaretic acid, ethanol, dimethyl sulfoxide, or ferrous ions but was inhibited by carbon monoxide, ketoconazole, and 1,2-epoxy-3,3,3-trichloropropane. Our data suggest that pseudomonal metabolism of polymorphonuclear leukocyte-derived arachidonic acid occurs during phagocytosis, probably by enzymatic epoxidation and hydroxylation via an oxygenase. By this means, potential proinflammatory effects of arachidonic acid or its metabolites may be modulated by P. aeruginosa at sites of infection in vivo.

  6. Metabolic Effects of the Very-Low-Carbohydrate Diets: Misunderstood "Villains" of Human Metabolism

    Directory of Open Access Journals (Sweden)

    Manninen Anssi H

    2004-12-01

    Full Text Available Abstract During very low carbohydrate intake, the regulated and controlled production of ketone bodies causes a harmless physiological state known as dietary ketosis. Ketone bodies flow from the liver to extra-hepatic tissues (e.g., brain for use as a fuel; this spares glucose metabolism via a mechanism similar to the sparing of glucose by oxidation of fatty acids as an alternative fuel. In comparison with glucose, the ketone bodies are actually a very good respiratory fuel. Indeed, there is no clear requirement for dietary carbohydrates for human adults. Interestingly, the effects of ketone body metabolism suggest that mild ketosis may offer therapeutic potential in a variety of different common and rare disease states. Also, the recent landmark study showed that a very-low-carbohydrate diet resulted in a significant reduction in fat mass and a concomitant increase in lean body mass in normal-weight men. Contrary to popular belief, insulin is not needed for glucose uptake and utilization in man. Finally, both muscle fat and carbohydrate burn in an amino acid flame.

  7. Therapeutic Targets of Triglyceride Metabolism as Informed by Human Genetics.

    Science.gov (United States)

    Bauer, Robert C; Khetarpal, Sumeet A; Hand, Nicholas J; Rader, Daniel J

    2016-04-01

    Human genetics has contributed to the development of multiple drugs to treat hyperlipidemia and coronary artery disease (CAD), most recently including antibodies targeting PCSK9 to reduce LDL cholesterol. Despite these successes, a large burden of CAD remains. Genetic and epidemiological studies have suggested that circulating triglyceride (TG)-rich lipoproteins (TRLs) are a causal risk factor for CAD, presenting an opportunity for novel therapeutic strategies. We discuss recent unbiased human genetics testing, including genome-wide association studies (GWAS) and whole-genome or -exome sequencing, that have identified the lipoprotein lipase (LPL) and hepatic lipogenesis pathways as important mechanisms in the regulation of circulating TRLs. Further strengthening the causal relationship between TRLs and CAD, findings such as these may provide novel targets for much-needed potential therapeutic interventions. Copyright © 2016. Published by Elsevier Ltd.

  8. Potential drug development candidates for human soil-transmitted helminthiases.

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    Piero Olliaro

    2011-06-01

    Full Text Available Few drugs are available for soil-transmitted helminthiasis (STH; the benzimidazoles albendazole and mebendazole are the only drugs being used for preventive chemotherapy as they can be given in one single dose with no weight adjustment. While generally safe and effective in reducing intensity of infection, they are contra-indicated in first-trimester pregnancy and have suboptimal efficacy against Trichuris trichiura. In addition, drug resistance is a threat. It is therefore important to find alternatives.We searched the literature and the animal health marketed products and pipeline for potential drug development candidates. Recently registered veterinary products offer advantages in that they have undergone extensive and rigorous animal testing, thus reducing the risk, cost and time to approval for human trials. For selected compounds, we retrieved and summarised publicly available information (through US Freedom of Information (FoI statements, European Public Assessment Reports (EPAR and published literature. Concomitantly, we developed a target product profile (TPP against which the products were compared.The paper summarizes the general findings including various classes of compounds, and more specific information on two veterinary anthelmintics (monepantel, emodepside and nitazoxanide, an antiprotozoal drug, compiled from the EMA EPAR and FDA registration files.Few of the compounds already approved for use in human or animal medicine qualify for development track decision. Fast-tracking to approval for human studies may be possible for veterinary compounds like emodepside and monepantel, but additional information remains to be acquired before an informed decision can be made.

  9. Analysis of Intra- and Intersubject Variability in Oral Drug Absorption in Human Bioequivalence Studies of 113 Generic Products.

    Science.gov (United States)

    Sugihara, Masahisa; Takeuchi, Susumu; Sugita, Masaru; Higaki, Kazutaka; Kataoka, Makoto; Yamashita, Shinji

    2015-12-07

    In this study, the data of 113 human bioequivalence (BE) studies of immediate release (IR) formulations of 74 active pharmaceutical ingredients (APIs) conducted at Sawai Pharmaceutical Co., Ltd., was analyzed to understand the factors affecting intra- and intersubject variabilities in oral drug absorption. The ANOVA CV (%) calculated from area under the time-concentration curve (AUC) in each BE study was used as an index of intrasubject variability (Vintra), and the relative standard deviation (%) in AUC was used as that of intersubject variability (Vinter). Although no significant correlation was observed between Vintra and Vinter of all drugs, Vintra of class 3 drugs was found to increase in association with a decrease in drug permeability (P(eff)). Since the absorption of class 3 drugs was rate-limited by the permeability, it was suggested that, for such drugs, the low P(eff) might be a risk factor to cause a large intrasubject variability. To consider the impact of poor water solubility on the variability in BE study, a parameter of P(eff)/Do (Do; dose number) was defined to discriminate the solubility-limited and dissolution-rate-limited absorption of class 2 drugs. It was found that the class 2 drugs with a solubility-limited absorption (P(eff)/Do high intrasubject variability. Furthermore, as a reason for high intra- or intersubject variability in AUC for class 1 drugs, effects of drug metabolizing enzymes were investigated. It was demonstrated that intrasubject variability was high for drugs metabolized by CYP3A4 while intersubject variability was high for drugs metabolized by CYP2D6. For CYP3A4 substrate drugs, the Km value showed the significant relation with Vintra, indicating that the affinity to the enzyme can be a parameter to predict the risk of high intrasubject variability. In conclusion, by analyzing the in house data of human BE study, low permeability, solubility-limited absorption, and high affinity to CYP3A4 are identified as risk factors for

  10. Age-dependent metabolic model of radionuclides in Human body

    International Nuclear Information System (INIS)

    Ye Changqing

    1986-01-01

    Age-dependent metabolic model of radionuclides in human body was introduced briefly. These data are necessary in setting up the secondary dose limit of internal exposure of the general public. For the gastro-intestinal tract model, it was shown that the dose of various sections of GI tract caused by unsoluble radioactive materials were influenced by the mass of section and mean residence time, both of which are age-dependent, but the absorption fraction f 1 through gastro-intestinal tract should be corrected only for the infant less than 1 year of age. For the lung model, it was indicated that the fraction of deposition or clearance of particles in the different compartments of lung were related to age. The doses of tracheobronchial and pulmonary compartment of adult for 222 Rn or 220 Rn with their decay products were one third of that of 6-years old child who received the maximum dose in comparison with other ages. The age-dependent metabolic models in organ and/or body of Tritium, Iodine-131, Caesium-137, radioactive Strontium, Radium and Plutonium were reported. A generalized approach for estimating the effect of age on deposition fractions and retention half-time were presented. Calculated results indicated that younger ages were characterized by increased deposition fraction and decreased half-time for retention. Representative examples were provided for 21 elements of current interest in health physics

  11. Targeting NAD+ metabolism in the human malaria parasite Plasmodium falciparum.

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    Jessica K O'Hara

    Full Text Available Nicotinamide adenine dinucleotide (NAD+ is an essential metabolite utilized as a redox cofactor and enzyme substrate in numerous cellular processes. Elevated NAD+ levels have been observed in red blood cells infected with the malaria parasite Plasmodium falciparum, but little is known regarding how the parasite generates NAD+. Here, we employed a mass spectrometry-based metabolomic approach to confirm that P. falciparum lacks the ability to synthesize NAD+ de novo and is reliant on the uptake of exogenous niacin. We characterized several enzymes in the NAD+ pathway and demonstrate cytoplasmic localization for all except the parasite nicotinamidase, which concentrates in the nucleus. One of these enzymes, the P. falciparum nicotinate mononucleotide adenylyltransferase (PfNMNAT, is essential for NAD+ metabolism and is highly diverged from the human homolog, but genetically similar to bacterial NMNATs. Our results demonstrate the enzymatic activity of PfNMNAT in vitro and demonstrate its ability to genetically complement the closely related Escherichia coli NMNAT. Due to the similarity of PfNMNAT to the bacterial enzyme, we tested a panel of previously identified bacterial NMNAT inhibitors and synthesized and screened twenty new derivatives, which demonstrate a range of potency against live parasite culture. These results highlight the importance of the parasite NAD+ metabolic pathway and provide both novel therapeutic targets and promising lead antimalarial compounds.

  12. Autonomous exoskeleton reduces metabolic cost of human walking.

    Science.gov (United States)

    Mooney, Luke M; Rouse, Elliott J; Herr, Hugh M

    2014-11-03

    Passive exoskeletons that assist with human locomotion are often lightweight and compact, but are unable to provide net mechanical power to the exoskeletal wearer. In contrast, powered exoskeletons often provide biologically appropriate levels of mechanical power, but the size and mass of their actuator/power source designs often lead to heavy and unwieldy devices. In this study, we extend the design and evaluation of a lightweight and powerful autonomous exoskeleton evaluated for loaded walking in (J Neuroeng Rehab 11:80, 2014) to the case of unloaded walking conditions. The metabolic energy consumption of seven study participants (85 ± 12 kg body mass) was measured while walking on a level treadmill at 1.4 m/s. Testing conditions included not wearing the exoskeleton and wearing the exoskeleton, in both powered and unpowered modes. When averaged across the gait cycle, the autonomous exoskeleton applied a mean positive mechanical power of 26 ± 1 W (13 W per ankle) with 2.12 kg of added exoskeletal foot-shank mass (1.06 kg per leg). Use of the leg exoskeleton significantly reduced the metabolic cost of walking by 35 ± 13 W, which was an improvement of 10 ± 3% (p = 0.023) relative to the control condition of not wearing the exoskeleton. The results of this study highlight the advantages of developing lightweight and powerful exoskeletons that can comfortably assist the body during walking.

  13. Light Chain Amyloid Fibrils Cause Metabolic Dysfunction in Human Cardiomyocytes.

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    Helen P McWilliams-Koeppen

    Full Text Available Light chain (AL amyloidosis is the most common form of systemic amyloid disease, and cardiomyopathy is a dire consequence, resulting in an extremely poor prognosis. AL is characterized by the production of monoclonal free light chains that deposit as amyloid fibrils principally in the heart, liver, and kidneys causing organ dysfunction. We have studied the effects of amyloid fibrils, produced from recombinant λ6 light chain variable domains, on metabolic activity of human cardiomyocytes. The data indicate that fibrils at 0.1 μM, but not monomer, significantly decrease the enzymatic activity of cellular NAD(PH-dependent oxidoreductase, without causing significant cell death. The presence of amyloid fibrils did not affect ATP levels; however, oxygen consumption was increased and reactive oxygen species were detected. Confocal fluorescence microscopy showed that fibrils bound to and remained at the cell surface with little fibril internalization. These data indicate that AL amyloid fibrils severely impair cardiomyocyte metabolism in a dose dependent manner. These data suggest that effective therapeutic intervention for these patients should include methods for removing potentially toxic amyloid fibrils.

  14. Glucose metabolism in cultured trophoblasts from human placenta

    International Nuclear Information System (INIS)

    Moe, A.J.; Farmer, D.R.; Nelson, D.M.; Smith, C.H.

    1990-01-01

    The development of appropriate placental trophoblast isolation and culture techniques enables the study of pathways of glucose utilization by this important cell layer in vitro. Trophoblasts from normal term placentas were isolated and cultured 24 hours and 72 hours in uncoated polystyrene culture tubes or tubes previously coated with a fibrin matrix. Trophoblasts cultured on fibrin are morphologically distinct from those cultured on plastic or other matrices and generally resemble in vivo syncytium. Cells were incubated up to 3 hours with 14 C-labeled glucose and reactions were stopped by addition of perchloric acid. 14 CO 2 production by trophoblasts increased linearly with time however the largest accumulation of label was in organic acids. Trophoblasts cultured in absence of fibrin utilized more glucose and accumulated more 14 C in metabolic products compared to cells cultured on fibrin. Glucose oxidation to CO 2 by the phosphogluconate (PG) pathway was estimated from specific yields of 14 CO 2 from [1- 14 C]-D-glucose and [6- 14 C]-D-glucose. Approximately 6% of glucose oxidation was by the PG pathway when cells were cultured on fibrin compared to approximately 1% by cells cultured in the absence of fibrin. The presence of a fibrin growth matrix appears to modulate the metabolism of glucose by trophoblast from human placenta in vitro

  15. Human macrophage hemoglobin-iron metabolism in vitro

    International Nuclear Information System (INIS)

    Custer, G.; Balcerzak, S.; Rinehart, J.

    1982-01-01

    An entirely in vitro technique was employed to characterize hemoglobin-iron metabolism by human macrophages obtained by culture of blood monocytes and pulmonary alveolar macrophages. Macrophages phagocytized about three times as many erythrocytes as monocytes and six times as many erythrocytes as pulmonary alveolar macrophages. The rate of subsequent release of 59 Fe to the extracellular transferrin pool was two- to fourfold greater for macrophages as compared to the other two cell types. The kinetics of 59 Fe-transferrin release were characterized by a relatively rapid early phase (hours 1-4) followed by a slow phase (hours 4-72) for all three cell types. Intracellular movement of iron was characterized by a rapid shift from hemoglobin to ferritin that was complete with the onset of the slow phase of extracellular release. A transient increase in 59 Fe associated with an intracellular protein eluting with transferrin was also observed within 1 hour after phagocytosis. The process of hemoglobin-iron release to extracellular transferrin was inhibited at 4 degrees C but was unaffected by inhibitory of protein synthesis, glycolysis, microtubule function, and microfilament function. These data emphasize the rapidity of macrophage hemoglobin iron metabolism, provide a model for characterization of this process in vitro, and in general confirm data obtained utilizing in vivo animal models

  16. RAS signalling in energy metabolism and rare human diseases.

    Science.gov (United States)

    Dard, L; Bellance, N; Lacombe, D; Rossignol, R

    2018-05-08

    The RAS pathway is a highly conserved cascade of protein-protein interactions and phosphorylation that is at the heart of signalling networks that govern proliferation, differentiation and cell survival. Recent findings indicate that the RAS pathway plays a role in the regulation of energy metabolism via the control of mitochondrial form and function but little is known on the participation of this effect in RAS-related rare human genetic diseases. Germline mutations that hyperactivate the RAS pathway have been discovered and linked to human developmental disorders that are known as RASopathies. Individuals with RASopathies, which are estimated to affect approximately 1/1000 human birth, share many overlapping characteristics, including cardiac malformations, short stature, neurocognitive impairment, craniofacial dysmorphy, cutaneous, musculoskeletal, and ocular abnormalities, hypotonia and a predisposition to developing cancer. Since the identification of the first RASopathy, type 1 neurofibromatosis (NF1), which is caused by the inactivation of neurofibromin 1, several other syndromes have been associated with mutations in the core components of the RAS-MAPK pathway. These syndromes include Noonan syndrome (NS), Noonan syndrome with multiple lentigines (NSML), which was formerly called LEOPARD syndrome, Costello syndrome (CS), cardio-facio-cutaneous syndrome (CFC), Legius syndrome (LS) and capillary malformation-arteriovenous malformation syndrome (CM-AVM). Here, we review current knowledge about the bioenergetics of the RASopathies and discuss the molecular control of energy homeostasis and mitochondrial physiology by the RAS pathway. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Molecular Characterization and Clinical Relevance of Metabolic Expression Subtypes in Human Cancers

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    Xinxin Peng

    2018-04-01

    Full Text Available Summary: Metabolic reprogramming provides critical information for clinical oncology. Using molecular data of 9,125 patient samples from The Cancer Genome Atlas, we identified tumor subtypes in 33 cancer types based on mRNA expression patterns of seven major metabolic processes and assessed their clinical relevance. Our metabolic expression subtypes correlated extensively with clinical outcome: subtypes with upregulated carbohydrate, nucleotide, and vitamin/cofactor metabolism most consistently correlated with worse prognosis, whereas subtypes with upregulated lipid metabolism showed the opposite. Metabolic subtypes correlated with diverse somatic drivers but exhibited effects convergent on cancer hallmark pathways and were modulated by highly recurrent master regulators across cancer types. As a proof-of-concept example, we demonstrated that knockdown of SNAI1 or RUNX1—master regulators of carbohydrate metabolic subtypes—modulates metabolic activity and drug sensitivity. Our study provides a system-level view of metabolic heterogeneity within and across cancer types and identifies pathway cross-talk, suggesting related prognostic, therapeutic, and predictive utility. : Peng et al. analyze a cohort of 9,125 TCGA samples across 33 cancer types to characterize tumor subtypes based on the expression of seven metabolic pathways. They find metabolic expression subtypes are associated with patient survivals and suggest the therapeutic and predictive relevance of subtype-related master regulators. Keywords: The Cancer Genome Atlas, tumor subtypes, prognostic markers, somatic drivers, master regulator, therapeutic targets, drug sensitivity, carbohydrate metabolism

  18. Preparation of human drug metabolites using fungal peroxygenases

    Science.gov (United States)

    Marzena Poraj-Kobielska; Matthias Kinne; René Ullrich; Katrin Scheibner; Gernot Kayser; Kenneth E. Hammel; Martin Hofrichter

    2011-01-01

    The synthesis of hydroxylated and O- or N-dealkylated human drug metabolites (HDMs) via selective monooxygenation remains a challenging task for synthetic organic chemists. Here we report that aromatic peroxygenases (APOs; EC 1.11.2.1) secreted by the agaric fungi Agrocybe aegerita and Coprinellus...

  19. Remote controlled capsules in human drug absorption (HDA) studies.

    Science.gov (United States)

    Wilding, Ian R; Prior, David V

    2003-01-01

    The biopharmaceutical complexity of today's new drug candidates provides significant challenges for pharmaceutical scientists in terms of both candidate selection and optimizing subsequent development strategy. In addition, life cycle management of marketed drugs has become an important income stream for pharmaceutical companies, but the selection of least risk/highest benefit strategies is far from simple. The proactive adoption of human drug absorption (HDA) studies using remote controlled capsules offers the pharmaceutical scientist significant guidance for planning a route through the maze of product development. This review examines the position of HDA studies in drug development, using a variety of case histories and an insightful update on remote controlled capsules to achieve site-specific delivery.

  20. On the Metabolism of Exogenous Ketones in Humans

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    Brianna J. Stubbs

    2017-10-01

    Full Text Available Background and aims: Currently there is considerable interest in ketone metabolism owing to recently reported benefits of ketosis for human health. Traditionally, ketosis has been achieved by following a high-fat, low-carbohydrate “ketogenic” diet, but adherence to such diets can be difficult. An alternative way to increase blood D-β-hydroxybutyrate (D-βHB concentrations is ketone drinks, but the metabolic effects of exogenous ketones are relatively unknown. Here, healthy human volunteers took part in three randomized metabolic studies of drinks containing a ketone ester (KE; (R-3-hydroxybutyl (R-3-hydroxybutyrate, or ketone salts (KS; sodium plus potassium βHB.Methods and Results: In the first study, 15 participants consumed KE or KS drinks that delivered ~12 or ~24 g of βHB. Both drinks elevated blood D-βHB concentrations (D-βHB Cmax: KE 2.8 mM, KS 1.0 mM, P < 0.001, which returned to baseline within 3–4 h. KS drinks were found to contain 50% of the L-βHB isoform, which remained elevated in blood for over 8 h, but was not detectable after 24 h. Urinary excretion of both D-βHB and L-βHB was <1.5% of the total βHB ingested and was in proportion to the blood AUC. D-βHB, but not L-βHB, was slowly converted to breath acetone. The KE drink decreased blood pH by 0.10 and the KS drink increased urinary pH from 5.7 to 8.5. In the second study, the effect of a meal before a KE drink on blood D-βHB concentrations was determined in 16 participants. Food lowered blood D-βHB Cmax by 33% (Fed 2.2 mM, Fasted 3.3 mM, P < 0.001, but did not alter acetoacetate or breath acetone concentrations. All ketone drinks lowered blood glucose, free fatty acid and triglyceride concentrations, and had similar effects on blood electrolytes, which remained normal. In the final study, participants were given KE over 9 h as three drinks (n = 12 or a continuous nasogastric infusion (n = 4 to maintain blood D-βHB concentrations greater than 1 mM. Both drinks

  1. Elucidation of xenobiotic metabolism pathways in human skin and human skin models by proteomic profiling.

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    Sven van Eijl

    Full Text Available BACKGROUND: Human skin has the capacity to metabolise foreign chemicals (xenobiotics, but knowledge of the various enzymes involved is incomplete. A broad-based unbiased proteomics approach was used to describe the profile of xenobiotic metabolising enzymes present in human skin and hence indicate principal routes of metabolism of xenobiotic compounds. Several in vitro models of human skin have been developed for the purpose of safety assessment of chemicals. The suitability of these epidermal models for studies involving biotransformation was assessed by comparing their profiles of xenobiotic metabolising enzymes with those of human skin. METHODOLOGY/PRINCIPAL FINDINGS: Label-free proteomic analysis of whole human skin (10 donors was applied and analysed using custom-built PROTSIFT software. The results showed the presence of enzymes with a capacity for the metabolism of alcohols through dehydrogenation, aldehydes through dehydrogenation and oxidation, amines through oxidation, carbonyls through reduction, epoxides and carboxylesters through hydrolysis and, of many compounds, by conjugation to glutathione. Whereas protein levels of these enzymes in skin were mostly just 4-10 fold lower than those in liver and sufficient to support metabolism, the levels of cytochrome P450 enzymes were at least 300-fold lower indicating they play no significant role. Four epidermal models of human skin had profiles very similar to one another and these overlapped substantially with that of whole skin. CONCLUSIONS/SIGNIFICANCE: The proteomics profiling approach was successful in producing a comprehensive analysis of the biotransformation characteristics of whole human skin and various in vitro skin models. The results show that skin contains a range of defined enzymes capable of metabolising different classes of chemicals. The degree of similarity of the profiles of the in vitro models indicates their suitability for epidermal toxicity testing. Overall, these

  2. Porphyrin metabolisms in human skin commensal Propionibacterium acnes bacteria: potential application to monitor human radiation risk.

    Science.gov (United States)

    Shu, M; Kuo, S; Wang, Y; Jiang, Y; Liu, Y-T; Gallo, R L; Huang, C-M

    2013-01-01

    Propionibacterium acnes (P. acnes), a Gram-positive anaerobic bacterium, is a commensal organism in human skin. Like human cells, the bacteria produce porphyrins, which exhibit fluorescence properties and make bacteria visible with a Wood's lamp. In this review, we compare the porphyrin biosynthesis in humans and P. acnes. Also, since P. acnes living on the surface of skin receive the same radiation exposure as humans, we envision that the changes in porphyrin profiles (the absorption spectra and/or metabolism) of P. acnes by radiation may mirror the response of human cells to radiation. The porphyrin profiles of P. acnes may be a more accurate reflection of radiation risk to the patient than other biodosimeters/biomarkers such as gene up-/down-regulation, which may be non-specific due to patient related factors such as autoimmune diseases. Lastly, we discuss the challenges and possible solutions for using the P. acnes response to predict the radiation risk.

  3. Drug-induced hypersensitivity syndrome with human herpesvirus-6 reactivation

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    Najeeba Riyaz

    2012-01-01

    Full Text Available A 45-year-old man, on carbamazepine for the past 3 months, was referred as a case of atypical measles. On examination, he had high-grade fever, generalized itchy rash, cough, vomiting and jaundice. A provisional diagnosis of drug hypersensitivity syndrome to carbamazepine was made with a differential diagnosis of viral exanthema with systemic complications. Laboratory investigations revealed leukocytosis with eosnophilia and elevated liver enzymes. Real-time multiplex polymerase chain reaction (PCR on throat swab and blood was suggestive of human herpesvirus-6 (HHV-6. Measles was ruled out by PCR and serology. The diagnosis of drug-induced hypersensitivity syndrome (DIHS was confirmed, which could explain all the features manifested by the patient. HHV-6 infects almost all humans by age 2 years. It infects and replicates in CD4 T lymphocytes and establishes latency in human peripheral blood monocytes or macrophages and early bone marrow progenitors. In DIHS, allergic reaction to the causative drug stimulates T cells, which leads to reactivation of the herpesvirus genome. DIHS is treated by withdrawal of the culprit drug and administration of systemic steroids. Our patient responded well to steroids and HHV-6 was negative on repeat real-time multiplex PCR at the end of treatment.

  4. Xenobiotic-metabolizing enzymes in the skin of rat, mouse, pig, guinea pig, man, and in human skin models.

    Science.gov (United States)

    Oesch, F; Fabian, E; Guth, K; Landsiedel, R

    2014-12-01

    The exposure of the skin to medical drugs, skin care products, cosmetics, and other chemicals renders information on xenobiotic-metabolizing enzymes (XME) in the skin highly interesting. Since the use of freshly excised human skin for experimental investigations meets with ethical and practical limitations, information on XME in models comes in the focus including non-human mammalian species and in vitro skin models. This review attempts to summarize the information available in the open scientific literature on XME in the skin of human, rat, mouse, guinea pig, and pig as well as human primary skin cells, human cell lines, and reconstructed human skin models. The most salient outcome is that much more research on cutaneous XME is needed for solid metabolism-dependent efficacy and safety predictions, and the cutaneous metabolism comparisons have to be viewed with caution. Keeping this fully in mind at least with respect to some cutaneous XME, some models may tentatively be considered to approximate reasonable closeness to human skin. For dermal absorption and for skin irritation among many contributing XME, esterase activity is of special importance, which in pig skin, some human cell lines, and reconstructed skin models appears reasonably close to human skin. With respect to genotoxicity and sensitization, activating XME are not yet judgeable, but reactive metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the "Overview and Conclusions" section in the end of this review.

  5. Non-clinical studies in the process of new drug development - Part II: Good laboratory practice, metabolism, pharmacokinetics, safety and dose translation to clinical studies.

    Science.gov (United States)

    Andrade, E L; Bento, A F; Cavalli, J; Oliveira, S K; Schwanke, R C; Siqueira, J M; Freitas, C S; Marcon, R; Calixto, J B

    2016-12-12

    The process of drug development involves non-clinical and clinical studies. Non-clinical studies are conducted using different protocols including animal studies, which mostly follow the Good Laboratory Practice (GLP) regulations. During the early pre-clinical development process, also known as Go/No-Go decision, a drug candidate needs to pass through several steps, such as determination of drug availability (studies on pharmacokinetics), absorption, distribution, metabolism and elimination (ADME) and preliminary studies that aim to investigate the candidate safety including genotoxicity, mutagenicity, safety pharmacology and general toxicology. These preliminary studies generally do not need to comply with GLP regulations. These studies aim at investigating the drug safety to obtain the first information about its tolerability in different systems that are relevant for further decisions. There are, however, other studies that should be performed according to GLP standards and are mandatory for the safe exposure to humans, such as repeated dose toxicity, genotoxicity and safety pharmacology. These studies must be conducted before the Investigational New Drug (IND) application. The package of non-clinical studies should cover all information needed for the safe transposition of drugs from animals to humans, generally based on the non-observed adverse effect level (NOAEL) obtained from general toxicity studies. After IND approval, other GLP experiments for the evaluation of chronic toxicity, reproductive and developmental toxicity, carcinogenicity and genotoxicity, are carried out during the clinical phase of development. However, the necessity of performing such studies depends on the new drug clinical application purpose.

  6. Albendazole metabolism in patients with neurocysticercosis: antipyrine as a multifunctional marker drug of cytochrome P450

    Directory of Open Access Journals (Sweden)

    M.P. Marques

    2002-02-01

    Full Text Available The present study investigates the isoform(s of cytochrome P450 (CYP involved in the metabolism of albendazole sulfoxide (ASOX to albendazole sulfone (ASON in patients with neurocysticercosis using antipyrine as a multifunctional marker drug. The study was conducted on 11 patients with neurocysticercosis treated with a multiple dose regimen of albendazole for 8 days (5 mg/kg every 8 h. On the 5th day of albendazole treatment, 500 mg antipyrine was administered po. Blood and urine samples were collected up to 72 h after antipyrine administration. Plasma concentrations of (+-ASOX, (--ASOX and ASON were determined by HPLC using a chiral phase column and detection by fluorescence. The apparent clearance (CL/f of ASON and of the (+ and (--ASOX enantiomers were calculated and compared to total antipyrine clearance (CL T and the clearance for the production of the three major antipyrine metabolites (CLm. A correlation (P<=0.05 was obtained only between the CL T of antipyrine and the CL/f of ASON (r = 0.67. The existence of a correlation suggests the involvement of CYP isoforms common to the metabolism of antipyrine and of ASOX to ASON. Since the CL T of antipyrine is a general measure of CYP enzymes but with a slight to moderate weight toward CYP1A2, we suggest the involvement of this enzyme in ASOX to ASON metabolism in man. The study supports the establishment of a specific marker drug of CYP1A2 in the study of the in vivo metabolism of ASOX to ASON.

  7. Metabolic activation of hepatotoxic drug (benzbromarone) induced mitochondrial membrane permeability transition

    Energy Technology Data Exchange (ETDEWEB)

    Shirakawa, Maho; Sekine, Shuichi; Tanaka, Ayaka [The Laboratory of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba (Japan); Horie, Toshiharu [Faculty of Pharmaceutical Sciences, Teikyo Heisei University, Tokyo (Japan); Ito, Kousei, E-mail: itokousei@chiba-u.jp [The Laboratory of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba (Japan)

    2015-10-01

    The risk of drug-induced liver injury (DILI) is of great concern to the pharmaceutical industry. It is well-known that metabolic activation of drugs to form toxic metabolites (TMs) is strongly associated with DILI onset. Drug-induced mitochondrial dysfunction is also strongly associated with increased risk of DILI. However, it is difficult to determine the target of TMs associated with exacerbation of DILI because of difficulties in identifying and purifying TMs. In this study, we propose a sequential in vitro assay system to assess TM formation and their ability to induce mitochondrial permeability transition (MPT) in a one-pot process. In this assay system, freshly-isolated rat liver mitochondria were incubated with reaction solutions of 44 test drugs preincubated with liver microsomes in the presence or absence of NADPH; then, NADPH-dependent MPT pore opening was assessed as mitochondrial swelling. In this assay system, several hepatotoxic drugs, including benzbromarone (BBR), significantly induced MPT in a NADPH-dependent manner. We investigated the rationality of using BBR as a model drug, since it showed the most prominent MPT in our assay system. Both the production of a candidate toxic metabolite of BBR (1′,6-(OH){sub 2} BBR) and NADPH-dependent MPT were inhibited by several cytochrome P450 (CYP) inhibitors (clotrimazole and SKF-525A, 100 μM). In summary, this assay system can be used to evaluate comprehensive metabolite-dependent MPT without identification or purification of metabolites. - Highlights: • We constructed a sequential assay system for toxic metabolite induced MPT in one pot. • 14 drugs (e.g. benzbromarone (BBR)) induced toxic metabolite dependent MPT. • Both the production of toxic metabolite and MPT could be inhibited by CYP inhibitors. • This system could evaluate the comprehensive MPT without purification of metabolites.

  8. Therapies for inborn errors of metabolism: what has the orphan drug act delivered?

    Science.gov (United States)

    Talele, Sonali S; Xu, Kui; Pariser, Anne R; Braun, M Miles; Farag-El-Massah, Sheiren; Phillips, M Ian; Thompson, Barry H; Coté, Timothy R

    2010-07-01

    The 1983 US Orphan Drug Act established a process through which promising therapies are designated as orphan products and, later, with satisfactory safety and efficacy data, receive marketing approval and fiscal incentives. We examined accomplishments in drug development for inborn errors of metabolism (IEMs). Food and Drug Administration data were used to identify orphan product designations and approvals for IEMs, and the trends for the past 26 years were summarized. Individual clinical development times (CDTs) from filing investigational new drug application to marketing approval were determined. We examined 1956 orphan product designations from 1983 through 2008 and found 93 (4.8%) for IEMs. Of those, 24 (25.8%) received marketing approval. This proportion of approval was significantly (P = .036) higher than that for non-IEM orphan products (17%). Among the IEM products, disorders of complex molecules received the most designations and approvals (61 and 11, respectively). Among the subgroups, lysosomal storage diseases received the most designations and approvals (43 and 9, respectively), whereas mitochondrial diseases (other than fatty acid oxidation disorders) received 7 designations with no approvals. We then examined the CDTs for the approved IEM products and found a median of 6.4 years (range: 2.6-25.1 years). Biological products had significantly shorter CDTs than drugs (mean: 4.6 vs 11.0 years; P = .003). For 26 years, the Orphan Drug Act has generated new therapies for IEMs. Why some IEMs have motivated successful drug development and others have not remains enigmatic; yet the needs of IEM patients without treatment are a certainty.

  9. Electrocatalytic oxidation of hydrogen peroxide on a platinum electrode in the imitation of oxidative drug metabolism of lidocaine

    NARCIS (Netherlands)

    Nouri-Nigjeh, Eslam; Bruins, Andries P.; Bischoff, Rainer; Permentier, Hjalmar P.

    2012-01-01

    Electrochemistry in combination with mass spectrometry has shown promise as a versatile technique not only in the analytical assessment of oxidative drug metabolism, but also for small-scale synthesis of drug metabolites. However, electrochemistry is generally limited to reactions initiated by

  10. Metabolism of tributyltin and triphenyltin by rat, hamster and human hepatic microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Ohhira, Shuji; Watanabe, Masatomo; Matsui, Hisao [Department of Hygiene, Dokkyo University School of Medicine, Mibu-machi, 321-0293, Tochigi (Japan)

    2003-03-01

    Tributyltin and triphenyltin are metabolized by cytochrome P-450 system enzymes, and their metabolic fate may contribute to the toxicity of the chemicals. In the current study, the in vitro metabolism of tributyltin and triphenyltin by rat, hamster and human hepatic microsomes was investigated to elucidate the metabolic competence for these compounds in humans. The metabolic reaction using microsome-NADPH system that is usually conducted was not applicable to in vitro metabolism of organotins, especially triphenyltin. We therefore examined the effects of dithiothreitol (DTT), one of the antioxidants for sulfhydryl groups, to determine the in vitro metabolism of tributyltin and triphenyltin. As a result, the treatment with 0.1 mM DTT in vitro increased the activity of the microsomal monooxygenase system for metabolism of tributyltin as well as triphenyltin; the total yield of tributyltin and triphenyltin metabolites as tin increased, respectively, by approximately 1.8 and 8.9 times for rat, 2.1 and 1.2 times for hamster, and 1.6 and 1.5 times for human. It is suggested that the organotins directly inactivate cytochrome P-450 because of the interaction with critical sulfhydryl groups of the hemoprotein. We confirmed the utility of this in vitro metabolic system using DTT in the hepatic microsomes of phenobarbital (PB)-pretreated and untreated hamsters. Thus, the in vitro metabolic system described here was applied to a comparative study of the metabolism of organotins in rats, hamsters and humans. Tributyltin was metabolized more readily than triphenyltin in all the species. In humans, the in vitro metabolic pattern resembled that of hamsters, which were susceptible to in vivo triphenyltin toxicity because of incompetent metabolism. It is possible that the hamster is a qualitatively and quantitatively suitable animal model for exploring the influence of tributyltin and triphenyltin in humans. (orig.)

  11. Genome-Scale Reconstruction of the Human Astrocyte Metabolic Network

    OpenAIRE

    Mart?n-Jim?nez, Cynthia A.; Salazar-Barreto, Diego; Barreto, George E.; Gonz?lez, Janneth

    2017-01-01

    Astrocytes are the most abundant cells of the central nervous system; they have a predominant role in maintaining brain metabolism. In this sense, abnormal metabolic states have been found in different neuropathological diseases. Determination of metabolic states of astrocytes is difficult to model using current experimental approaches given the high number of reactions and metabolites present. Thus, genome-scale metabolic networks derived from transcriptomic data can be used as a framework t...

  12. Glucose Metabolism of Human Prostate Cancer Mouse Xenografts

    Directory of Open Access Journals (Sweden)

    Hossein Jadvar

    2005-04-01

    Full Text Available We hypothesized that the glucose metabolism of prostate cancer is modulated by androgen. We performed in vivo biodistribution and imaging studies of [F-18] fluorodeoxyglucose (FDG accumulation in androgen-sensitive (CWR-22 and androgen-independent (PC-3 human prostate cancer xenografts implanted in castrated and noncastrated male athymic mice. The growth pattern of the CWR-22 tumor was best approximated by an exponential function (tumor size in mm3 = 14.913 e0.108 × days, R2 = .96, n = 5. The growth pattern of the PC-3 tumor was best approximated by a quadratic function (tumor size in mm3 = 0.3511 × days2 + 49.418 × day −753.33, R2 = .96, n = 3. The FDG accumulation in the CWR-22 tumor implanted in the castrated mice was significantly lower, by an average of 55%, in comparison to that implanted in the noncastrated host (1.27 vs. 2.83, respectively, p < .05. The 3-week maximal standardized uptake value (SUVmax was 0.99 ± 0.43 (mean ± SD for CWR-22 and 1.21 ± 0.32 for PC-3, respectively. The 5-week SUVmax was 1.22 ± 0.08 for CWR-22 and 1.35 ± 0.17 for PC-3, respectively. The background muscle SUVmax was 0.53 ± 0.11. Glucose metabolism was higher in the PC-3 tumor than in the CWR-22 tumor at both the 3-week (by 18% and the 5-week (by 9.6% micro-PET imaging sessions. Our results support the notions that FDG PET may be useful in the imaging evaluation of response to androgen ablation therapy and in the early prediction of hormone refractoriness in men with metastatic prostate cancer.

  13. Brain lactate metabolism in humans with subarachnoid hemorrhage.

    Science.gov (United States)

    Oddo, Mauro; Levine, Joshua M; Frangos, Suzanne; Maloney-Wilensky, Eileen; Carrera, Emmanuel; Daniel, Roy T; Levivier, Marc; Magistretti, Pierre J; LeRoux, Peter D

    2012-05-01

    Lactate is central for the regulation of brain metabolism and is an alternative substrate to glucose after injury. Brain lactate metabolism in patients with subarachnoid hemorrhage has not been fully elucidated. Thirty-one subarachnoid hemorrhage patients monitored with cerebral microdialysis (CMD) and brain oxygen (PbtO(2)) were studied. Samples with elevated CMD lactate (>4 mmol/L) were matched to PbtO(2) and CMD pyruvate and categorized as hypoxic (PbtO(2) 119 μmol/L) versus nonhyperglycolytic. Median per patient samples with elevated CMD lactate was 54% (interquartile range, 11%-80%). Lactate elevations were more often attributable to cerebral hyperglycolysis (78%; interquartile range, 5%-98%) than brain hypoxia (11%; interquartile range, 4%-75%). Mortality was associated with increased percentage of samples with elevated lactate and brain hypoxia (28% [interquartile range 9%-95%] in nonsurvivors versus 9% [interquartile range 3%-17%] in survivors; P=0.02) and lower percentage of elevated lactate and cerebral hyperglycolysis (13% [interquartile range, 1%-87%] versus 88% [interquartile range, 27%-99%]; P=0.07). Cerebral hyperglycolytic lactate production predicted good 6-month outcome (odds ratio for modified Rankin Scale score, 0-3 1.49; CI, 1.08-2.05; P=0.016), whereas increased lactate with brain hypoxia was associated with a reduced likelihood of good outcome (OR, 0.78; CI, 0.59-1.03; P=0.08). Brain lactate is frequently elevated in subarachnoid hemorrhage patients, predominantly because of hyperglycolysis rather than hypoxia. A pattern of increased cerebral hyperglycolytic lactate was associated with good long-term recovery. Our data suggest that lactate may be used as an aerobic substrate by the injured human brain.

  14. What is the contribution of human FMO3 in the N-oxygenation of selected therapeutic drugs and drugs of abuse?

    Science.gov (United States)

    Wagmann, Lea; Meyer, Markus R; Maurer, Hans H

    2016-09-06

    Little is known about the role of flavin-containing monooxygenases (FMOs) in the metabolism of xenobiotics. FMO3 is the isoform in adult human liver with the highest impact on drug metabolism. The aim of the presented study was to elucidate the contribution of human FMO3 to the N-oxygenation of selected therapeutic drugs and drugs of abuse (DOAs). Its contribution to the in vivo hepatic net clearance of the N-oxygenation products was calculated by application of an extended relative activity factor (RAF) approach to differentiate from contribution of cytochrome P450 (CYP) isoforms. FMO3 and CYP substrates were identified using pooled human liver microsomes after heat inactivation and chemical inhibition, or single enzyme incubations. Kinetic parameters were subsequently determined using recombinant human enzymes and mass spectrometric analysis via authentic reference standards or simple peak areas of the products divided by those of the internal standard. FMO3 was identified as enzyme mainly responsible for the formation of N,N-diallyltryptamine N-oxide and methamphetamine hydroxylamine (>80% contribution for both). A contribution of 50 and 30% was calculated for the formation of N,N-dimethyltryptamine N-oxide and methoxypiperamide N-oxide, respectively. However, FMO3 contributed with less than 5% to the formation of 3-bromomethcathinone hydroxylamine, amitriptyline N-oxide, and clozapine N-oxide. There was no significant difference in the contributions when using calibrations with reference metabolite standards or peak area ratio calculations. The successful application of a modified RAF approach including FMO3 proved the importance of FMO3 in the N-oxygenation of DOAs in human metabolism. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Metabolic approaches to enhance transdermal drug delivery. 1. Effect of lipid synthesis inhibitors.

    Science.gov (United States)

    Tsai, J C; Guy, R H; Thornfeldt, C R; Gao, W N; Feingold, K R; Elias, P M

    1996-06-01

    The intercellular domains of the stratum corneum, which contain a mixture of cholesterol, free fatty acids, and ceramides, mediate both the epidermal permeability barrier and the transdermal delivery of both lipophilic and hydrophilic molecules. Prior studies have shown that each of the three key lipid classes is required for normal barrier function. For example, selective inhibition of either cholesterol, fatty acid, or ceramide synthesis in the epidermis delays barrier recovery rates after barrier perturbation of hairless mouse skin in vivo. In this study, we investigated the potential of certain inhibitors of lipid synthesis to enhance the transdermal delivery of lidocaine or caffeine as a result of their capacity to perturb barrier homeostasis. After acetone disruption of the barrier, the extent of lidocaine delivery and the degree of altered barrier function paralleled each other. Moreover, the further alteration in barrier function produced by either the fatty acid synthesis inhibitor 5-(tetradecyloxy)-2-furancarboxylic acid (TOFA), the cholesterol synthesis inhibitor fluvastatin (FLU), or cholesterol sulfate (CS) resulted in a further increase in lidocaine absorption. Furthermore, coapplications of TOFA and CS together caused an additive increase in lidocaine uptake. Finally, a comparable increase in drug delivery occurred when the barrier was disrupted initially with DMSO instead of acetone; coapplications of TOFA and FLU together again delayed barrier recovery and increased drug delivery by about 8-fold vs delivery from a standard enhancing vehicle. Whereas these metabolic inhibitors also variably increased the octanol/water partitioning of the drugs studied (perhaps via complexion or pH alterations), physicochemical effects of the inhibitors alone did not alter drug uptake in intact skin; i.e., passive mechanisms alone cannot account for the net increase in drug delivery. Our results show that modulations of epidermal lipid biosynthesis, following

  16. Dissimilarities in the metabolism of antiretroviral drugs used in HIV pre-exposure prophylaxis in colon and vagina tissues.

    Science.gov (United States)

    To, Elaine E; Hendrix, Craig W; Bumpus, Namandjé N

    2013-10-01

    Attempts to prevent HIV infection through pre-exposure prophylaxis (PrEP) include topical application of anti-HIV drugs to the mucosal sites of infection; however, a potential role for local drug metabolizing enzymes in modulating the exposure of the mucosal tissues to these drugs has yet to be explored. Here we present the first report that enzymes belonging to the cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) families of drug metabolizing enzymes are expressed and active in vaginal and colorectal tissue using biopsies collected from healthy volunteers. In doing so, we discovered that dapivirine and maraviroc, a non-nucleoside reverse transcriptase inhibitor and an entry inhibitor currently in development as microbicides for HIV PrEP, are differentially metabolized in colorectal tissue and vaginal tissue. Taken together, these data should help to guide the optimization of small molecules being developed for HIV PrEP. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Metabolism and disposition of [14C]brivanib alaninate after oral administration to rats, monkeys, and humans.

    Science.gov (United States)

    Gong, Jiachang; Gan, Jinping; Caceres-Cortes, Janet; Christopher, Lisa J; Arora, Vinod; Masson, Eric; Williams, Daphne; Pursley, Janice; Allentoff, Alban; Lago, Michael; Tran, Scott B; Iyer, Ramaswamy A

    2011-05-01

    Brivanib [(R)-1-(4-(4-fluoro-2-methyl-1H-indol-5-yloxy)-5-methylpyrrolo[1,2,4]triazin-6-yloxy)propan-2-ol, BMS-540215] is a potent and selective dual inhibitor of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) signaling pathways. Its alanine prodrug, brivanib alaninate [(1R,2S)-2-aminopropionic acid 2-[4-(4-fluoro-2-methyl-1H-indol-5-yloxy)-5-methylpyrrolo[2,1-f][1,2,4]triazin-6-yloxy]-1-methylethyl ester, BMS-582664], is currently under development as an oral agent for the treatment of cancer. This study describes the in vivo biotransformation of brivanib after a single oral dose of [(14)C]brivanib alaninate to intact rats, bile duct-cannulated (BDC) rats, intact monkeys, BDC monkeys, and humans. Fecal excretion was the primary route of elimination of drug-derived radioactivity in animals and humans. In BDC rats and monkeys, the majority of radioactivity was excreted in bile. Brivanib alaninate was rapidly and completely converted via hydrolysis to brivanib in vivo. The area under the curve from zero to infinity of brivanib accounted for 14.2 to 54.3% of circulating radioactivity in plasma in animals and humans, suggesting that metabolites contributed significantly to the total drug-related radioactivity. In plasma from animals and humans, brivanib was a prominent circulating component. All the metabolites that humans were exposed to were also present in toxicological species. On the basis of metabolite exposure and activity against VEGF and FGF receptors of the prominent human circulating metabolites, only brivanib is expected to contribute to the pharmacological effects in humans. Unchanged brivanib was not detected in urine or bile samples, suggesting that metabolic clearance was the primary route of elimination. The primary metabolic pathways were oxidative and conjugative metabolism of brivanib.

  18. Study of cerebral metabolism of glucose in normal human brain correlated with age

    International Nuclear Information System (INIS)

    Si, M.

    2007-01-01

    Full text: The objective was to determine whether cerebral metabolism in various regions of the brain differs with advancing age by using 18F-FDG PET instrument and SPM software. Materials and Methods We reviewed clinical information of 295 healthy normal samples who were examined by a whole body GE Discovery LS PET-CT instrument in our center from Aug. 2004 to Dec. 2005.They (with the age ranging from 21 to 88; mean age+/-SD: 49.77+/-13.51) were selected with: (i)absence of clear focal brain lesions (epilepsy.cerebrovascular diseases etc);(ii) absence of metabolic diseases, such as hyperthyroidism, hypothyroidism and diabetes;(iii) absence of psychiatric disorders and abuse of drugs and alcohol. They were sub grouped into six groups with the interval of 10 years old starting from 21, and the gender, educational background and serum glucose were matched. All subgroups were compared to the control group of 31-40 years old (84 samples; mean age+/-SD: 37.15+/-2.63). All samples were injected with 18F-FDG (5.55MBq/kg), 45-60 minutes later, their brains were scanned for 10min. Pixel-by-pixel t-statistic analysis was applied to all brain images using the Statistical parametric mapping (SPM2) .The hypometabolic areas (p < 0. 01 or p<0.001, uncorrected) were identified in the Stereotaxic coordinate human brain atlas and three-dimensional localized by MNI Space utility (MSU) software. Results:Relative hypometabolic brain areas detected are mainly in the cortical structures such as bilateral prefrontal cortex, superior temporal gyrus(BA22), parietal cortex (inferior parietal lobule and precuneus(BA40, insula(BA13)), parahippocampal gyrus and amygdala (p<0.01).It is especially apparent in the prefrontal cortex (BA9)and sensory-motor cortex(BA5, 7) (p<0.001), while basal ganglia and cerebellum remained metabolically unchanged with advancing age. Conclusions Regional cerebral metabolism of glucose shows a descent tendency with aging, especially in the prefrontal cortex (BA9)and

  19. Impact of maternal metabolic abnormalities in pregnancy on human milk and subsequent infant metabolic development: methodology and design

    Directory of Open Access Journals (Sweden)

    Hamilton Jill K

    2010-10-01

    Full Text Available Abstract Background Childhood obesity is on the rise and is a major risk factor for type 2 diabetes later in life. Recent evidence indicates that abnormalities that increase risk for diabetes may be initiated early in infancy. Since the offspring of women with diabetes have an increased long-term risk for obesity and type 2 diabetes, the impact of maternal metabolic abnormalities on early nutrition and infant metabolic trajectories is of considerable interest. Human breast milk, the preferred food during infancy, contains not only nutrients but also an array of bioactive substances including metabolic hormones. Nonetheless, only a few studies have reported concentrations of metabolic hormones in human milk specifically from women with metabolic abnormalities. We aim to investigate the impact of maternal metabolic abnormalities in pregnancy on human milk hormones and subsequently on infant development over the first year of life. The objective of this report is to present the methodology and design of this study. Methods/Design The current investigation is a prospective study conducted within ongoing cohort studies of women and their offspring. Pregnant women attending outpatient obstetrics clinics in Toronto, Canada were recruited. Between April 2009 and July 2010, a total of 216 pregnant women underwent a baseline oral glucose tolerance test and provided medical and lifestyle history. Follow-up visits and telephone interviews are conducted and expected to be completed in October 2011. Upon delivery, infant birth anthropometry measurements and human breast milk samples are collected. At 3 and 12 months postpartum, mothers and infants are invited for follow-up assessments. Interim telephone interviews are conducted during the first year of offspring life to characterize infant feeding and supplementation behaviors. Discussion An improved understanding of the link between maternal metabolic abnormalities in pregnancy and early infant nutrition may

  20. Impact of maternal metabolic abnormalities in pregnancy on human milk and subsequent infant metabolic development: methodology and design.

    Science.gov (United States)

    Ley, Sylvia H; O'Connor, Deborah L; Retnakaran, Ravi; Hamilton, Jill K; Sermer, Mathew; Zinman, Bernard; Hanley, Anthony J

    2010-10-06

    Childhood obesity is on the rise and is a major risk factor for type 2 diabetes later in life. Recent evidence indicates that abnormalities that increase risk for diabetes may be initiated early in infancy. Since the offspring of women with diabetes have an increased long-term risk for obesity and type 2 diabetes, the impact of maternal metabolic abnormalities on early nutrition and infant metabolic trajectories is of considerable interest. Human breast milk, the preferred food during infancy, contains not only nutrients but also an array of bioactive substances including metabolic hormones. Nonetheless, only a few studies have reported concentrations of metabolic hormones in human milk specifically from women with metabolic abnormalities. We aim to investigate the impact of maternal metabolic abnormalities in pregnancy on human milk hormones and subsequently on infant development over the first year of life. The objective of this report is to present the methodology and design of this study. The current investigation is a prospective study conducted within ongoing cohort studies of women and their offspring. Pregnant women attending outpatient obstetrics clinics in Toronto, Canada were recruited. Between April 2009 and July 2010, a total of 216 pregnant women underwent a baseline oral glucose tolerance test and provided medical and lifestyle history. Follow-up visits and telephone interviews are conducted and expected to be completed in October 2011. Upon delivery, infant birth anthropometry measurements and human breast milk samples are collected. At 3 and 12 months postpartum, mothers and infants are invited for follow-up assessments. Interim telephone interviews are conducted during the first year of offspring life to characterize infant feeding and supplementation behaviors. An improved understanding of the link between maternal metabolic abnormalities in pregnancy and early infant nutrition may assist in the development of optimal prevention and intervention

  1. Epstein–Barr Virus-Induced Metabolic Rearrangements in Human B-Cell Lymphomas

    Directory of Open Access Journals (Sweden)

    Pier P. Piccaluga

    2018-06-01

    Full Text Available Tumor metabolism has been the object of several studies in the past, leading to the pivotal observation of a consistent shift toward aerobic glycolysis (so-called Warburg effect. More recently, several additional investigations proved that tumor metabolism is profoundly affected during tumorigenesis, including glucose, lipid and amino-acid metabolism. It is noticeable that metabolic reprogramming can represent a suitable therapeutic target in many cancer types. Epstein–Barr virus (EBV was the first virus linked with cancer in humans when Burkitt lymphoma (BL was described. Besides other well-known effects, it was recently demonstrated that EBV can induce significant modification in cell metabolism, which may lead or contribute to neoplastic transformation of human cells. Similarly, virus-induced tumorigenesis is characterized by relevant metabolic abnormalities directly induced by the oncoviruses. In this article, the authors critically review the most recent literature concerning EBV-induced metabolism alterations in lymphomas.

  2. Transdermal hormone therapy in postmenopausal women: A review of metabolic effects and drug delivery technologies

    Directory of Open Access Journals (Sweden)

    Nathan W Kopper

    2008-10-01

    Full Text Available Nathan W Kopper, Jennifer Gudeman, Daniel J ThompsonKV Pharmaceutical, St. Louis, MO, USAAbstract: Vasomotor symptoms (VMS associated with menopause can cause significant discomfort and decrease the quality of life for women in the peri-menopausal and post-menopausal stages of life. Hormone therapy (HT is the mainstay of treatment for menopausal symptoms and is currently the only therapy proven effective for VMS. Numerous HT options are available to treat VMS, including estrogen-only and estrogen-progestogen combination products to meet the needs of both hysterectomized and nonhysterectomized women. In addition to selecting an appropriate estrogen or estrogen-progestogen combination, consideration should be given to the route of administration to best suit the needs of the patient. Delivery systems for hormone therapy include oral tablets, transdermal patches, transdermal topical (nonpatch products, and intravaginal preparations. Oral is currently the most commonly utilized route of administration in the United States. However, evidence suggests that oral delivery may lead to some undesirable physiologic effects caused by significant gut and hepatic metabolism. Transdermal drug delivery may mitigate some of these effects by avoiding gut and hepatic first-pass metabolism. Advantages of transdermal delivery include the ability to administer unmetabolized estradiol directly to the blood stream, administration of lower doses compared to oral products, and minimal stimulation of hepatic protein production. Several estradiol transdermal delivery technologies are available, including various types of patches, topical gels, and a transdermal spray.Keywords: estradiol, hormone therapy, menopause, transdermal drug delivery, vasomotor symptoms

  3. Effects of dibutyl phthalate on lipid metabolism and drug metabolising enzyme system in rats

    International Nuclear Information System (INIS)

    Arakaki, Mitsuo; Ariyoshi, Toshihiko.

    1976-01-01

    Effects of dibutyl phthalate (DBP) on the liver constituents and the drug metabolizing enzyme system were investigated in rats. 1. In the experiments at a single oral dose of DBP (630 or 1260 mg/kg), the glycogen content was decreased only at the high dose, but no effects were observed on the contents of glycogen, triglyceride, microsomal protein and cytochromes, and on the activities of drug metabolizing enzymes. 2. In the repeated oral dose of DBP (630 or 1260 mg/kg/day) for 5 days, the ratio of liver weight to body weight was increased in both female and male rats, whereas the increases of cytochrome P-450 content and aniline hydroxylase activity were noted only in male rats. However, the contents of liver triglyceride, phospholipids, and cholesterol were unchanged. On the other hand, serum cholesterol content which showed the tendency to be decreased at the low dose was significantly decreased at the high dose. 3. In the incorporation of 1- 14 C-acetate into liver and serum lipids after repeated oral dose of DBP (630 mg/kg/day) for 5 days in male rats, the incorporation into triglyceride showed tendency to be increased, whereas the incorporation into cholesterol and cholesterol ester remained unchanged in vivo and in vitro. (auth.)

  4. Novel 3D Culture Systems for Studies of Human Liver Function and Assessments of the Hepatotoxicity of Drugs and Drug Candidates.

    Science.gov (United States)

    Lauschke, Volker M; Hendriks, Delilah F G; Bell, Catherine C; Andersson, Tommy B; Ingelman-Sundberg, Magnus

    2016-12-19

    The liver is an organ with critical importance for drug treatment as the disposition and response to a given drug is often determined by its hepatic metabolism. Patient-specific factors can entail increased susceptibility to drug-induced liver injury, which constitutes a major risk for drug development programs causing attrition of promising drug candidates or costly withdrawals in postmarketing stages. Hitherto, mainly animal studies and 2D hepatocyte systems have been used for the examination of human drug metabolism and toxicity. Yet, these models are far from satisfactory due to extensive species differences and because hepatocytes in 2D cultures rapidly dedifferentiate resulting in the loss of their hepatic phenotype and functionality. With the increasing comprehension that 3D cell culture systems more accurately reflect in vivo physiology, in the recent decade more and more research has focused on the development and optimization of various 3D culture strategies in an attempt to preserve liver properties in vitro. In this contribution, we critically review these developments, which have resulted in an arsenal of different static and perfused 3D models. These systems include sandwich-cultured hepatocytes, spheroid culture platforms, and various microfluidic liver or multiorgan biochips. Importantly, in many of these models hepatocytes maintain their phenotype for prolonged times, which allows probing the potential of newly developed chemical entities to cause chronic hepatotoxicity. Moreover, some platforms permit the investigation of drug action in specific genetic backgrounds or diseased hepatocytes, thereby significantly expanding the repertoire of tools to detect drug-induced liver injuries. It is concluded that the development of 3D liver models has hitherto been fruitful and that systems are now at hand whose sensitivity and specificity in detecting hepatotoxicity are superior to those of classical 2D culture systems. For the future, we highlight the

  5. Proline and hydroxyproline metabolism: implications for animal and human nutrition

    Science.gov (United States)

    Bazer, Fuller W.; Burghardt, Robert C.; Johnson, Gregory A.; Kim, Sung Woo; Knabe, Darrell A.; Li, Peng; Li, Xilong; McKnight, Jason R.; Satterfield, M. Carey; Spencer, Thomas E.

    2013-01-01

    Proline plays important roles in protein synthesis and structure, metabolism (particularly the synthesis of arginine, polyamines, and glutamate via pyrroline-5-carboxylate), and nutrition, as well as wound healing, antioxidative reactions, and immune responses. On a pergram basis, proline plus hydroxyproline are most abundant in collagen and milk proteins, and requirements of proline for whole-body protein synthesis are the greatest among all amino acids. Therefore, physiological needs for proline are particularly high during the life cycle. While most mammals (including humans and pigs) can synthesize proline from arginine and glutamine/glutamate, rates of endogenous synthesis are inadequate for neonates, birds, and fish. Thus, work with young pigs (a widely used animal model for studying infant nutrition) has shown that supplementing 0.0, 0.35, 0.7, 1.05, 1.4, and 2.1% proline to a proline-free chemically defined diet containing 0.48% arginine and 2% glutamate dose dependently improved daily growth rate and feed efficiency while reducing concentrations of urea in plasma. Additionally, maximal growth performance of chickens depended on at least 0.8% proline in the diet. Likewise, dietary supplementation with 0.07, 0.14, and 0.28% hydroxyproline (a metabolite of proline) to a plant protein-based diet enhanced weight gains of salmon. Based on its regulatory roles in cellular biochemistry, proline can be considered as a functional amino acid for mammalian, avian, and aquatic species. Further research is warranted to develop effective strategies of dietary supplementation with proline or hydroxyproline to benefit health, growth, and development of animals and humans. PMID:20697752

  6. Instruments for radiation measurement in life sciences (4). VI. Use of Accelerator mass spectrometry in studies on drug metabolism and pharmacokinetics

    International Nuclear Information System (INIS)

    Ikeda, Toshihiko

    2005-01-01

    Non-clinical and clinical uses of accelerator mass spectrometry (AMS) are described mainly on studies of drug metabolism and pharmacokinetics from a view of new drug development. AMS is applicable as a highly sensitive method to measure plasma drug concentrations. Measurement of 14 C-labeled compounds less than 1 dpm/sample or of parathyroid hormone-related protein (PTHrP), in combination of AMS and radioimmunoassay without radioactive waste release is described as an example. Cases of measuring DNA-adduct are also described involving human studies using 14 C-mutagen (a quinoxaline derivative derived from burned amino acid, given in a microdose of 304 ng/kg, 4.3 μCi/body). Plasma concentration measurement, mass balance study and metabolite identification of 14 C-GI1817771 (a drug candidate) are a typical AMS application for a pharmacokinetic study in human in a microdose (121 Bq/body). Metabolites of 14 C-compound A in rat platelet are identified by the author. As above, AMS makes it possible to conduct the pharmacokinetic study in human at a microdose with no significant radiation exposure, which will promote the efficient new drug development. (N.I.)

  7. Human Metabolism and Interactions of Deployment-Related Chemicals

    Science.gov (United States)

    2008-08-01

    stimulated by CPO (Fig. 6). Coincidently, α- naphthoflavone inhibited CYP1A2 metabolism of flavonoids /23/ and stimulated CYP3A4 metabolism of...by flavonoids of benzo[a]pyrene hydroxylation by cytochrome P-450 isozymes from rabbit liver microsomes, J. Biol. Chem. 1981; 256: 10897-10901. 17...P450-mediated metabolism of dietary flavonoids , Food Chem. Toxicol. 2002; 40: 609-616. 24. Cameron MD, Wen B, Allen KE, Roberts AG, Schuman JT

  8. Human Metabolism and Interactions of Deployment-Related Chemicals

    National Research Council Canada - National Science Library

    Hodgson, Ernest; Brimfield, Alan A; Goldstein, Joyce E; Rose, Randy L; Wallace, Andrew D

    2008-01-01

    .... The metabolism of chlorpyrifos, DEET, permethrin, pyridostigmine bromide, sulfur mustard, naphthalene and nonane as well as a number of their metabolites and related chemicals was investigated...

  9. Prediction of Human Pharmacokinetic Profile After Transdermal Drug Application Using Excised Human Skin.

    Science.gov (United States)

    Yamamoto, Syunsuke; Karashima, Masatoshi; Arai, Yuta; Tohyama, Kimio; Amano, Nobuyuki

    2017-09-01

    Although several mathematical models have been reported for the estimation of human plasma concentration profiles of drug substances after dermal application, the successful cases that can predict human pharmacokinetic profiles are limited. Therefore, the aim of this study is to investigate the prediction of human plasma concentrations after dermal application using in vitro permeation parameters obtained from excised human skin. The in vitro skin permeability of 7 marketed drug products was evaluated. The plasma concentration-time profiles of the drug substances in humans after their dermal application were simulated using compartment models and the clinical pharmacokinetic parameters. The transdermal process was simulated using the in vitro skin permeation rate and lag time assuming a zero-order absorption. These simulated plasma concentration profiles were compared with the clinical data. The result revealed that the steady-state plasma concentration of diclofenac and the maximum concentrations of nicotine, bisoprolol, rivastigmine, and lidocaine after topical application were within 2-fold of the clinical data. Furthermore, the simulated concentration profiles of bisoprolol, nicotine, and rivastigmine reproduced the decrease in absorption due to drug depletion from the formulation. In conclusion, this simple compartment model using in vitro human skin permeation parameters as zero-order absorption predicted the human plasma concentrations accurately. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  10. [Influence of valproic acid (depakine I.V.) on human placenta metabolism--experimental model].

    Science.gov (United States)

    Semczuk-Sikora, Anna; Rogowska, Wanda; Semczuk, Marian

    2003-08-01

    The pregnancy in women with epilepsy is associated with an increased incidence of congenital malformations in offspring. Currently, anti-epileptic drugs (AEDs) are concerned to be a major etiologic factor of abnormal fetal development but the pathomechanism of teratogenicity of AEDs is complex and not well understood. The purpose of this study was to evaluate an influence of one of the AED-valproic acid (VPA) on placental metabolism (glucose consumption and lactate production). Term human placental cotyledons were perfused in vitro using a recycling perfusion of maternal and fetal circulations. A total 18 placentas were perfused either with 75 micrograms/ml of VPA (therapeutic dose) or with 225 micrograms/ml of VPA (toxic dose). Eight placentas were perfused with a medium without VPA and served as controls. During 2.5 h of experiment, both maternal and fetal glucose consumption and lactate production were measured every 30 minutes. The introduction of different concentrations of VPA into the perfusion system did not effect placental glucose consumption and lactate production rates in both maternal and fetal compartments. The teratogenic effect of valproic acid is not associated with metabolic disturbances of glucose or lactate in the placental tissue.

  11. Human embryonic stem cell technologies and drug discovery.

    Science.gov (United States)

    Jensen, Janne; Hyllner, Johan; Björquist, Petter

    2009-06-01

    Development of new drugs is costly and takes huge resources into consideration. The big pharmaceutical companies are currently facing increasing developmental costs and a lower success-rate of bringing new compounds to the market. Therefore, it is now of outmost importance that the drug-hunting companies minimize late attritions due to sub-optimal pharmacokinetic properties or unexpected toxicity when entering the clinical programs. To achieve this, a strong need to test new candidate drugs in assays of high human relevance in vitro as early as possible has been identified. The traditionally used cell systems are however remarkably limited in this sense, and new improved technologies are of greatest importance. The human embryonic stem cells (hESC) is one of the most powerful cell types known. They have not only the possibility to divide indefinitely; these cells can also differentiate into all mature cell types of the human body. This makes them potentially very valuable for pharmaceutical development, spanning from use as tools in early target studies, DMPK or safety assessment, as screening models to find new chemical entities modulating adult stem cell fate, or as the direct use in cell therapies. This review illustrates the use of hESC in the drug discovery process, today, as well as in a future perspective. This will specifically be exemplified with the most important cell type for pharmaceutical development-the hepatocyte. We discuss how hESC-derived hepatocyte-like cells could improve this process, and how these cells should be cultured if optimized functionality and usefulness should be achieved. J. Cell. Physiol. 219: 513-519, 2009. (c) 2009 Wiley-Liss, Inc.

  12. Effect of Various Diets on the Expression of Phase-I Drug Metabolizing Enzymes in Livers of Mice

    Science.gov (United States)

    Guo, Ying; Cui, Julia Yue; Lu, Hong; Klaassen, Curtis D.

    2017-01-01

    Previous studies have shown that diets can alter the metabolism of drugs; however, it is difficult to compare the effects of multiple diets on drug metabolism among different experimental settings. Phase-I related genes play a major role in the biotransformation of pro-drugs and drugs.In the current study, effects of nine diets on the mRNA expression of phase-I drug-metabolizing enzymes in livers of mice were simultaneously investigated. Compared to the AIN-93M purified diet (control), 73 of the 132 critical phase-I drug metabolizing genes were differentially regulated by at least one diet. Diet restriction produced the most number of changed genes (51), followed by the atherogenic diet (27), high-fat diet (25), standard rodent chow (21), western diet (20), high-fructose diet (5), EFA deficient diet (3), and low n-3 FA diet (1). The mRNAs of the Fmo family changed most, followed by Cyp2b and 4a subfamilies, as well as Por (From 1121 to 21-fold increase of theses mRNAs). There were 59 genes not altered by any of these diets.The present results may improve the interpretation of studies with mice and aid in determining effective and safe doses for individuals with different nutritional diets. PMID:25733028

  13. Using open source computational tools for predicting human metabolic stability and additional absorption, distribution, metabolism, excretion, and toxicity properties.

    Science.gov (United States)

    Gupta, Rishi R; Gifford, Eric M; Liston, Ted; Waller, Chris L; Hohman, Moses; Bunin, Barry A; Ekins, Sean

    2010-11-01

    Ligand-based computational models could be more readily shared between researchers and organizations if they were generated with open source molecular descriptors [e.g., chemistry development kit (CDK)] and modeling algorithms, because this would negate the requirement for proprietary commercial software. We initially evaluated open source descriptors and model building algorithms using a training set of approximately 50,000 molecules and a test set of approximately 25,000 molecules with human liver microsomal metabolic stability data. A C5.0 decision tree model demonstrated that CDK descriptors together with a set of Smiles Arbitrary Target Specification (SMARTS) keys had good statistics [κ = 0.43, sensitivity = 0.57, specificity = 0.91, and positive predicted value (PPV) = 0.64], equivalent to those of models built with commercial Molecular Operating Environment 2D (MOE2D) and the same set of SMARTS keys (κ = 0.43, sensitivity = 0.58, specificity = 0.91, and PPV = 0.63). Extending the dataset to ∼193,000 molecules and generating a continuous model using Cubist with a combination of CDK and SMARTS keys or MOE2D and SMARTS keys confirmed this observation. When the continuous predictions and actual values were binned to get a categorical score we observed a similar κ statistic (0.42). The same combination of descriptor set and modeling method was applied to passive permeability and P-glycoprotein efflux data with similar model testing statistics. In summary, open source tools demonstrated predictive results comparable to those of commercial software with attendant cost savings. We discuss the advantages and disadvantages of open source descriptors and the opportunity for their use as a tool for organizations to share data precompetitively, avoiding repetition and assisting drug discovery.

  14. The role of gut microbiota in human metabolism

    NARCIS (Netherlands)

    Vrieze, A.

    2013-01-01

    This thesis supports the hypothesis that gut microbiota can be viewed as an ‘exteriorised organ’ that contributes to energy metabolism and the modulation of our immune system. Following Koch’s postulates, it has now been shown that gut microbiota are associated with metabolic disease and that these

  15. Hepatic metabolism of toluene after gastrointestinal uptake in humans

    DEFF Research Database (Denmark)

    Bælum, Jesper; Mølhave, Lars; Honoré Hansen, S

    1993-01-01

    The metabolism of toluene and the influence of small doses of ethanol were measured in eight male volunteers after gastrointestinal uptake, the toluene concentration in alveolar air and the urinary excretion of hippuric acid and ortho-cresol being used as the measures of metabolism. During toluene...

  16. Circadian rhythms, metabolism, and chrononutrition in rodents and humans

    Science.gov (United States)

    Chrononutrition is an emerging discipline that builds on the intimate relation between endogenous circadian (24-h) rhythms and metabolism. Circadian regulation of metabolic function can be observed from the level of intracellular biochemistry to whole-organism physiology and even postprandial respon...

  17. Diet-microbiota interactions as moderators of human metabolism

    DEFF Research Database (Denmark)

    Sonnenburg, Justin L; Bäckhed, Gert Fredrik

    2016-01-01

    It is widely accepted that obesity and associated metabolic diseases, including type 2 diabetes, are intimately linked to diet. However, the gut microbiota has also become a focus for research at the intersection of diet and metabolic health. Mechanisms that link the gut microbiota with obesity...

  18. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  19. Metabolic fate of desomorphine elucidated using rat urine, pooled human liver preparations, and human hepatocyte cultures as well as its detectability using standard urine screening approaches.

    Science.gov (United States)

    Richter, Lilian H J; Kaminski, Yeda Rumi; Noor, Fozia; Meyer, Markus R; Maurer, Hans H

    2016-09-01

    Desomorphine is an opioid misused as "crocodile", a cheaper alternative to heroin. It is a crude synthesis product homemade from codeine with toxic byproducts. The aim of the present work was to investigate the metabolic fate of desomorphine in vivo using rat urine and in vitro using pooled human liver microsomes and cytosol as well as human liver cell lines (HepG2 and HepaRG) by Orbitrap-based liquid chromatography-high resolution-tandem mass spectrometry or hydrophilic interaction liquid chromatography. According to the identified metabolites, the following metabolic steps could be proposed: N-demethylation, hydroxylation at various positions, N-oxidation, glucuronidation, and sulfation. The cytochrome P450 (CYP) initial activity screening revealed CYP3A4 to be the only CYP involved in all phase I steps. UDP-glucuronyltransferase (UGT) initial activity screening showed that UGT1A1, UGT1A8, UGT1A9, UGT1A10, UGT2B4, UGT2B7, UGT2B15, and UGT2B17 formed desomorphine glucuronide. Among the tested in vitro models, HepaRG cells were identified to be the most suitable tool for prediction of human hepatic phase I and II metabolism of drugs of abuse. Finally, desomorphine (crocodile) consumption should be detectable by all standard urine screening approaches mainly via the parent compound and/or its glucuronide assuming similar kinetics in rats and humans.

  20. HUMAN TRAFFICKING DRUG TRAFFICKING, AND THE DEATH PENALTY

    Directory of Open Access Journals (Sweden)

    Felicity Gerry

    2016-12-01

    Full Text Available Both Australia and Indonesia have made commitments to combatting human trafficking.  Through the experience of Mary Jane Veloso it can be seen that it is most often the vulnerable ‘mule’ that is apprehended by law enforcement and not the powerful leaders of crime syndicates. It is unacceptable that those vulnerable individuals may face execution for acts committed under threat of force, coercion, fraud, deception or abuse of power. For this reason it is vital that a system of victim identification is developed, including better training for law enforcement, legal representatives and members of the judiciary. This paper builds on submissions by authors for Australian Parliamentary Inquiry into Human Trafficking, and focusses on issues arising in the complex cross section of human trafficking, drug trafficking, and the death penalty with particular attention on identifying victims and effective reporting mechanisms in both Australia and Indonesia. It concludes that, in the context of human trafficking both countries could make three main improvements to law and policy, among others, 1 enactment of laws that create clear mandatory protection for human trafficking victims; 2 enactment of criminal laws that provides complete defence for victim of human trafficking; 3 enactment of corporate reporting mechanisms. Systemic protection and support is not sufficiently available without clear legislative protection as this paper suggests together with standardised referral mechanisms and effective financial reporting mechanisms. The implementation can be achieved through collaborative responses and inter-agency coordination with data collection and properly trained specialists.

  1. The promising anticancer drug 3-bromopyruvate is metabolized through glutathione conjugation which affects chemoresistance and clinical practice: An evidence-based view.

    Science.gov (United States)

    El Sayed, Salah Mohamed; Baghdadi, Hussam; Zolaly, Mohammed; Almaramhy, Hamdi H; Ayat, Mongi; Donki, Jagadish G

    2017-03-01

    3-Bromopyruvate (3BP) is a promising effective anticancer drug against many different tumors in children and adults. 3BP exhibited strong anticancer effects in both preclinical and human studies e.g. energy depletion, oxidative stress, anti-angiogenesis, anti-metastatic effects, targeting cancer stem cells and antagonizing the Warburg effect. There is no report about 3BP metabolism to guide researchers and oncologists to improve clinical practice and prevent drug resistance. In this article, we provide evidences that 3BP is metabolized through glutathione (GSH) conjugation as a novel report where 3BP was confirmed to be attached to GSH followed by permanent loss of pharmacological effects in a picture similar to cisplatin. Both cisplatin and 3BP are alkylating agents. Reported decrease in endogenous cellular GSH content upon 3BP treatment was confirmed to be due to the formation of 3BP-GSH complex i.e. GSH consumption for conjugation with 3BP. Cancer cells having high endogenous GSH exhibit resistance to 3BP while 3BP sensitive cells acquire resistance upon adding exogenous GSH. Being a thiol blocker, 3BP may attack thiol groups in tissues and serum proteins e.g. albumin and GSH. That may decrease 3BP-induced anticancer effects and the functions of those proteins. We proved here that 3BP metabolism is different from metabolism of hydroxypyruvate that results from metabolism of D-serine using D-amino acid oxidase. Clinically, 3BP administration should be monitored during albumin infusion and protein therapy where GSH should be added to emergency medications. GSH exerts many physiological effects and is safe for human administration both orally and intravenously. Based on that, reported GSH-induced inhibition of 3BP effects makes 3BP effects reversible, easily monitored and easily controlled. This confers a superiority of 3BP over many anticancer agents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Evaluations of in vitro metabolism, drug-drug interactions mediated by reversible and time-dependent inhibition of CYPs, and plasma protein binding of MMB4 DMS.

    Science.gov (United States)

    Hong, S Peter; Lusiak, Bozena D; Burback, Brian L; Johnson, Jerry D

    2013-01-01

    1,1'-Methylenebis[4-[(hydroxyimino)methyl]-pyridinium] (MMB4) dimethanesulfonate (DMS) is a bisquaternary pyridinium aldoxime that reactivates acetylcholinesterase inhibited by organophosphorus nerve agent. Drug metabolism and plasma protein binding for MMB4 DMS were examined using various techniques and a wide range of species. When (14)C-MMB4 DMS was incubated in liver microsomes, 4-pyridine aldoxime (4-PA) and an additional metabolite were detected in all species tested. Identity of the additional metabolite was postulated to be isonicotinic acid (INA) based on liquid chromatography with a tandem mass spectrometry analysis, which was confirmed by comparison with authentic INA. Formation of INA was dependent on species, with the highest level found in monkey liver microsomes. The MMB4 DMS exhibited reversible inhibition in a concentration-dependent manner toward cytochrome P450 1A2 (CYP1A2), CYP2C9, CYP2C19, CYP2D6, and CYP3A4 in human liver microsomes showing the highest inhibition for CYP2D6. Human recombinant CYPs were used to evaluate inhibitory curves more adequately and determine detailed kinetic constants for reversible inhibition and potential time-dependent inhibition (TDI). The MMB4 DMS exhibited reversible inhibition toward human-recombinant CYP2D6 with an inhibition constant (K i) value of 66.6 µmol/L. Based on the k inact/K I values, MMB4 DMS was found to exhibit the most potent TDI toward CYP2D6. The MMB4 DMS at 5 different concentrations was incubated in plasma for 5 hours using an equilibrium dialysis device. For all species tested, there were no concentration-dependent changes in plasma protein binding, ranging from 10% to 17%. These results suggest that MMB4 was not extensively bound to plasma protein, and there were no overt species-related differences in the extent of MMB4 bound to plasma protein.

  3. Metabolic Pathway of Icotinib In Vitro: The Differential Roles of CYP3A4, CYP3A5, and CYP1A2 on Potential Pharmacokinetic Drug-Drug Interaction.

    Science.gov (United States)

    Zhang, TianHong; Zhang, KeRong; Ma, Li; Li, Zheng; Wang, Juan; Zhang, YunXia; Lu, Chuang; Zhu, Mingshe; Zhuang, XiaoMei

    2018-04-01

    Icotinib is the first self-developed small molecule drug in China for targeted therapy of non-small cell lung cancer. To date, systematic studies on the pharmacokinetic drug-drug interaction of icotinib were limited. By identifying metabolite generated in human liver microsomes and revealing the contributions of major cytochromes P450 (CYPs) in the formation of major metabolites, the aim of the present work was to understand the mechanisms underlying pharmacokinetic and pharmacological variability in clinic. A liquid chromatography/UV/high-resolution mass spectrometer method was developed to characterize the icotinib metabolites. The formation of 6 major metabolites was studied in recombinant CYP isozymes and human liver microsomes with specific inhibitors to identify the CYPs responsible for icotinib metabolism. The metabolic pathways observed in vitro are consistent with those observed in human. Results demonstrated that the metabolites are predominantly catalyzed by CYP3A4 (77%∼87%), with a moderate contribution from CYP3A5 (5%∼15%) and CYP1A2 (3.7%∼7.5%). The contribution of CYP2C8, 2C9, 2C19, and 2D6 is insignificant. Based on our observations, to minimize drug-drug interaction risk in clinic, coprescription of icotinib with strong CYP3A inhibitors or inducers must be weighed. CYP1A2, a highly inducible enzyme in the smoking population, may also represent a determinant of pharmacokinetic and pharmacological variability of icotinib, especially in lung cancer patients with smoking history. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  4. Dynamics of human whole body amino acid metabolism

    International Nuclear Information System (INIS)

    Young, V.R.

    1981-01-01

    The mechanism of regulation of the nitrogen metabolism in humans under various nutritional and physiological states was examined using stable isotopes. In the simultaneous continuous infusion of 1- [ 13 ] - leucine and α- [ 15 N]- lysine, their fluxed decreased when individuals received lower protein intake. The rates of oxidation and incorporation into body proteins of leucine changed in parallel with the protein intake. Such effects of diet on whole body leucine kinetics were modified by the energy state and dietary energy level. The nitrogen balance was also improved by an excess level of dietary energy. When the intake of dietary protein was lowered below the maintenance level, the whole body flux and de novo synthesis of glycine were lowered, but alanine synthesis was clearly increased. The intravenous infusion of glucose at 4 mg/kg.min, which causes increase in excess blood sugar and plasma insulin, increased the alanine flux, but had no effect on the glycine flux. The rate of albumin synthesis, determined by giving 15 N-glycine orally every 3 hr, decreased with the lowered intake of dietary protein in young men, but not in elderly men. This explains why the serum albumin synthesis increases with the increase in the intake of dietary protein in young men, but not in elderly men. The rate of whole body protein synthesis in young men receiving the L-amino acid diets providing with the required intake of specific amino acid was much lower than that in the men receiving the diets providing with generous intake of specific amino acid. Thus the control mechanism to maintain the homeostasis of body nitrogen and amino acids is related in some unknown way to the nutritional requirement of the hosts. (Kaihara, S.)

  5. Role of cytochrome P450-mediated metabolism and involvement of reactive metabolite formations on antiepileptic drug-induced liver injuries.

    Science.gov (United States)

    Sasaki, Eita; Yokoi, Tsuyoshi

    2018-01-01

    Several drugs have been withdrawn from the market or restricted to avoid unexpected adverse outcomes. Drug-induced liver injury (DILI) is a serious issue for drug development. Among DILIs, idiosyncratic DILIs have been a serious problem in drug development and clinical uses. Idiosyncratic DILI is most often unrelated to pharmacological effects or the dosing amount of a drug. The number of drugs that cause idiosyncratic DILI continue to grow in part because no practical preclinical tests have emerged that can identify drug candidates with the potential for developing idiosyncratic DILIs. Nevertheless, the implications of drug metabolism-related factors and immune-related factors on idiosyncratic DILIs has not been fully clarified because this toxicity can not be reproduced in animals. Therefore, accumulated evidence for the mechanisms of the idiosyncratic toxicity has been limited to only in vitro studies. This review describes current knowledge of the effects of cytochrome P450 (CYP)-mediated metabolism and its detoxification abilities based on studies of idiosyncratic DILI animal models developed recently. This review also focused on antiepileptic drugs, phenytoin (diphenyl hydantoin, DPH) and carbamazepine (CBZ), which have rarely caused severe adverse reactions, such as fulminant hepatitis, and have been recognized as sources of idiosyncratic DILI. The studies of animal models of idiosyncratic DILIs have produced new knowledge of chronic administration, CYP inductions/inhibitions, glutathione contents, and immune-related factors for the initiation of idiosyncratic DILIs. Considering changes in the drug metabolic profile and detoxification abilities, idiosyncratic DILIs caused by antiepileptic drugs will lead to understanding the mechanisms of these DILIs.

  6. Genetic analysis of human traits in vitro: drug response and gene expression in lymphoblastoid cell lines.

    Directory of Open Access Journals (Sweden)

    Edwin Choy

    2008-11-01

    Full Text Available Lymphoblastoid cell lines (LCLs, originally collected as renewable sources of DNA, are now being used as a model system to study genotype-phenotype relationships in human cells, including searches for QTLs influencing levels of individual mRNAs and responses to drugs and radiation. In the course of attempting to map genes for drug response using 269 LCLs from the International HapMap Project, we evaluated the extent to which biological noise and non-genetic confounders contribute to trait variability in LCLs. While drug responses could be technically well measured on a given day, we observed significant day-to-day variability and substantial correlation to non-genetic confounders, such as baseline growth rates and metabolic state in culture. After correcting for these confounders, we were unable to detect any QTLs with genome-wide significance for drug response. A much higher proportion of variance in mRNA levels may be attributed to non-genetic factors (intra-individual variance--i.e., biological noise, levels of the EBV virus used to transform the cells, ATP levels than to detectable eQTLs. Finally, in an attempt to improve power, we focused analysis on those genes that had both detectable eQTLs and correlation to drug response; we were unable to detect evidence that eQTL SNPs are convincingly associated with drug response in the model. While LCLs are a promising model for pharmacogenetic experiments, biological noise and in vitro artifacts may reduce power and have the potential to create spurious association due to confounding.

  7. Metabolic profiling using HPLC allows classification of drugs according to their mechanisms of action in HL-1 cardiomyocytes

    International Nuclear Information System (INIS)

    Strigun, Alexander; Wahrheit, Judith; Beckers, Simone; Heinzle, Elmar; Noor, Fozia

    2011-01-01

    Along with hepatotoxicity, cardiotoxic side effects remain one of the major reasons for drug withdrawals and boxed warnings. Prediction methods for cardiotoxicity are insufficient. High content screening comprising of not only electrophysiological characterization but also cellular molecular alterations are expected to improve the cardiotoxicity prediction potential. Metabolomic approaches recently have become an important focus of research in pharmacological testing and prediction. In this study, the culture medium supernatants from HL-1 cardiomyocytes after exposure to drugs from different classes (analgesics, antimetabolites, anthracyclines, antihistamines, channel blockers) were analyzed to determine specific metabolic footprints in response to the tested drugs. Since most drugs influence energy metabolism in cardiac cells, the metabolite 'sub-profile' consisting of glucose, lactate, pyruvate and amino acids was considered. These metabolites were quantified using HPLC in samples after exposure of cells to test compounds of the respective drug groups. The studied drug concentrations were selected from concentration response curves for each drug. The metabolite profiles were randomly split into training/validation and test set; and then analysed using multivariate statistics (principal component analysis and discriminant analysis). Discriminant analysis resulted in clustering of drugs according to their modes of action. After cross validation and cross model validation, the underlying training data were able to predict 50%-80% of conditions to the correct classification group. We show that HPLC based characterisation of known cell culture medium components is sufficient to predict a drug's potential classification according to its mode of action.

  8. Genome-wide discovery of drug-dependent human liver regulatory elements.

    Directory of Open Access Journals (Sweden)

    Robin P Smith

    2014-10-01

    Full Text Available Inter-individual variation in gene regulatory elements is hypothesized to play a causative role in adverse drug reactions and reduced drug activity. However, relatively little is known about the location and function of drug-dependent elements. To uncover drug-associated elements in a genome-wide manner, we performed RNA-seq and ChIP-seq using antibodies against the pregnane X receptor (PXR and three active regulatory marks (p300, H3K4me1, H3K27ac on primary human hepatocytes treated with rifampin or vehicle control. Rifampin and PXR were chosen since they are part of the CYP3A4 pathway, which is known to account for the metabolism of more than 50% of all prescribed drugs. We selected 227 proximal promoters for genes with rifampin-dependent expression or nearby PXR/p300 occupancy sites and assayed their ability to induce luciferase in rifampin-treated HepG2 cells, finding only 10 (4.4% that exhibited drug-dependent activity. As this result suggested a role for distal enhancer modules, we searched more broadly to identify 1,297 genomic regions bearing a conditional PXR occupancy as well as all three active regulatory marks. These regions are enriched near genes that function in the metabolism of xenobiotics, specifically members of the cytochrome P450 family. We performed enhancer assays in rifampin-treated HepG2 cells for 42 of these sequences as well as 7 sequences that overlap linkage-disequilibrium blocks defined by lead SNPs from pharmacogenomic GWAS studies, revealing 15/42 and 4/7 to be functional enhancers, respectively. A common African haplotype in one of these enhancers in the GSTA locus was found to exhibit potential rifampin hypersensitivity. Combined, our results further suggest that enhancers are the predominant targets of rifampin-induced PXR activation, provide a genome-wide catalog of PXR targets and serve as a model for the identification of drug-responsive regulatory elements.

  9. Utilization of carbon 13-labelled stable isotopes for studying drug toxicity on cellular metabolism

    International Nuclear Information System (INIS)

    Herve, M.; Wietzerbin, J.; Tran-Dinh, S.

    1994-01-01

    A new approach for studying the effects of two drugs, amphotericine B (AMB), an anti-fungal antibiotic, and 2-deoxy-D-glucose (DG), on the glucose metabolism in brewer yeast cells (Saccharomyces cerevisiae), is presented; AMB interacts with the membrane sterols, inducing formation of pores through which ions and small molecules can pass. DG may enter in the cytosol, where it is phosphoryled by hexokinase into deoxy-D-glucose 6-phosphate (DG6P) which disappears very slowly. DG slows down the glycolysis process and induces the formation of new substances. This paper shows the advantages of utilizing carbon 13-labelled substrates combined to the NMR-13C and NMR-1H techniques. 6 figs., 5 refs

  10. Identification of the Consistently Altered Metabolic Targets in Human Hepatocellular CarcinomaSummary

    Directory of Open Access Journals (Sweden)

    Zeribe Chike Nwosu

    2017-09-01

    Full Text Available Background & Aims: Cancer cells rely on metabolic alterations to enhance proliferation and survival. Metabolic gene alterations that repeatedly occur in liver cancer are largely unknown. We aimed to identify metabolic genes that are consistently deregulated, and are of potential clinical significance in human hepatocellular carcinoma (HCC. Methods: We studied the expression of 2,761 metabolic genes in 8 microarray datasets comprising 521 human HCC tissues. Genes exclusively up-regulated or down-regulated in 6 or more datasets were defined as consistently deregulated. The consistent genes that correlated with tumor progression markers (ECM2 and MMP9 (Pearson correlation P < .05 were used for Kaplan-Meier overall survival analysis in a patient cohort. We further compared proteomic expression of metabolic genes in 19 tumors vs adjacent normal liver tissues. Results: We identified 634 consistent metabolic genes, ∼60% of which are not yet described in HCC. The down-regulated genes (n = 350 are mostly involved in physiologic hepatocyte metabolic functions (eg, xenobiotic, fatty acid, and amino acid metabolism. In contrast, among consistently up-regulated metabolic genes (n = 284 are those involved in glycolysis, pentose phosphate pathway, nucleotide biosynthesis, tricarboxylic acid cycle, oxidative phosphorylation, proton transport, membrane lipid, and glycan metabolism. Several metabolic genes (n = 434 correlated with progression markers, and of these, 201 predicted overall survival outcome in the patient cohort analyzed. Over 90% of the metabolic targets significantly altered at the protein level were similarly up- or down-regulated as in genomic profile. Conclusions: We provide the first exposition of the consistently altered metabolic genes in HCC and show that these genes are potentially relevant targets for onward studies in preclinical and clinical contexts. Keywords: Liver Cancer, HCC, Tumor Metabolism

  11. Inhibition of human aromatase complex (CYP19) by antiepileptic drugs

    DEFF Research Database (Denmark)

    Jacobsen, Naja Wessel; Halling-Sørensen, Bent; Birkved, Franziska Maria A Kramer

    2008-01-01

    of 1.4-49.7 mM. Carbamazepine, gabapentin, primidone, topiramate and vigabatrin showed no inhibition. Additionally, binary drug combinations were tested to investigate if combination therapy could potentiate the aromatase inhibition. Additive inhibition was seen in combination experiments...... with valproate and phenobarbital. When adding carbamazepine to a range of valproate concentrations no additional inhibition was seen. The data for some of the AEDs show that side effects on steroid synthesis in humans due to inhibition of aromatase should be considered....

  12. Methods of measuring metabolism during surgery in humans: focus on the liver-brain relationship.

    Science.gov (United States)

    Battezzati, Alberto; Bertoli, Simona

    2004-09-01

    The purpose of this work is to review recent advances in setting methods and models for measuring metabolism during surgery in humans. Surgery, especially solid organ transplantation, may offer unique experimental models in which it is ethically acceptable to gain information on difficult problems of amino acid and protein metabolism. Two areas are reviewed: the metabolic study of the anhepatic phase during liver transplantation and brain microdialysis during cerebral surgery. The first model offers an innovative approach to understand the relative role of liver and extrahepatic organs in gluconeogenesis, and to evaluate whether other organs can perform functions believed to be exclusively or almost exclusively performed by the liver. The second model offers an insight to intracerebral metabolism that is closely bound to that of the liver. The recent advances in metabolic research during surgery provide knowledge immediately useful for perioperative patient management and for a better control of surgical stress. The studies during the anhepatic phase of liver transplantation have showed that gluconeogenesis and glutamine metabolism are very active processes outside the liver. One of the critical organs for extrahepatic glutamine metabolism is the brain. Microdialysis studies helped to prove that in humans there is an intense trafficking of glutamine, glutamate and alanine among neurons and astrocytes. This delicate network is influenced by systemic amino acid metabolism. The metabolic dialogue between the liver and the brain is beginning to be understood in this light in order to explain the metabolic events of brain damage during liver failure.

  13. New Aspects of an Old Drug – Diclofenac Targets MYC and Glucose Metabolism in Tumor Cells

    Science.gov (United States)

    Gottfried, Eva; Lang, Sven A.; Renner, Kathrin; Bosserhoff, Anja; Gronwald, Wolfram; Rehli, Michael; Einhell, Sabine; Gedig, Isabel; Singer, Katrin; Seilbeck, Anton; Mackensen, Andreas; Grauer, Oliver; Hau, Peter; Dettmer, Katja; Andreesen, Reinhard; Oefner, Peter J.; Kreutz, Marina

    2013-01-01

    Non-steroidal anti-inflammatory drugs such as diclofenac exhibit potent anticancer effects. Up to now these effects were mainly attributed to its classical role as COX-inhibitor. Here we show novel COX-independent effects of diclofenac. Diclofenac significantly diminished MYC expression and modulated glucose metabolism resulting in impaired melanoma, leukemia, and carcinoma cell line proliferation in vitro and reduced melanoma growth in vivo. In contrast, the non-selective COX inhibitor aspirin and the COX-2 specific inhibitor NS-398 had no effect on MYC expression and glucose metabolism. Diclofenac significantly decreased glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA), and monocarboxylate transporter 1 (MCT1) gene expression in line with a decrease in glucose uptake and lactate secretion. A significant intracellular accumulation of lactate by diclofenac preceded the observed effect on gene expression, suggesting a direct inhibitory effect of diclofenac on lactate efflux. While intracellular lactate accumulation impairs cellular proliferation and gene expression, it does not inhibit MYC expression as evidenced by the lack of MYC regulation by the MCT inhibitor α-cyano-4-hydroxycinnamic acid. Finally, in a cell line with a tetracycline-regulated c-MYC gene, diclofenac decreased proliferation both in the presence and absence of c-MYC. Thus, diclofenac targets tumor cell proliferation via two mechanisms, that is inhibition of MYC and lactate transport. Based on these results, diclofenac holds potential as a clinically applicable MYC and glycolysis inhibitor supporting established tumor therapies. PMID:23874405

  14. The histamine H₃ receptor as a therapeutic drug target for metabolic disorders: status, challenges and opportunities.

    Science.gov (United States)

    Plancher, Jean-Marc

    2011-01-01

    Since the histamine-3 receptor (H₃R) was cloned in 1999, huge efforts have been made by most of the key players in the pharmaceutical industry as well as in smaller biotech companies to increase the knowledge on this peculiar receptor, with the ultimate goal of bringing new drugs to the market. This review gives a survey on the most valuable chemical tools discovered so far and the significant pharmacological experiments on metabolic disease models published to date. Pharmacology of H₃R antagonists turns out to be very complex due to various functional activities, species selectivity, presence of H₃R isoforms and the poorly understood dichotomy in efficacy between CNS and metabolic disease models. Adding an extra layer of complexity, researchers have to cope with some recurrent safety concerns, some of them being tightly linked to the nature of the H₃R pharmacophore. Therefore this review also strives to summarize the major hurdles and some of the contradictions seen in the H₃R field, together with a brief overview of the clinical trials currently running.

  15. Human Vascular Microphysiological System for in vitro Drug Screening.

    Science.gov (United States)

    Fernandez, C E; Yen, R W; Perez, S M; Bedell, H W; Povsic, T J; Reichert, W M; Truskey, G A

    2016-02-18

    In vitro human tissue engineered human blood vessels (TEBV) that exhibit vasoactivity can be used to test human toxicity of pharmaceutical drug candidates prior to pre-clinical animal studies. TEBVs with 400-800 μM diameters were made by embedding human neonatal dermal fibroblasts or human bone marrow-derived mesenchymal stem cells in dense collagen gel. TEBVs were mechanically strong enough to allow endothelialization and perfusion at physiological shear stresses within 3 hours after fabrication. After 1 week of perfusion, TEBVs exhibited endothelial release of nitric oxide, phenylephrine-induced vasoconstriction, and acetylcholine-induced vasodilation, all of which were maintained up to 5 weeks in culture. Vasodilation was blocked with the addition of the nitric oxide synthase inhibitor L-N(G)-Nitroarginine methyl ester (L-NAME). TEBVs elicited reversible activation to acute inflammatory stimulation by TNF-α which had a transient effect upon acetylcholine-induced relaxation, and exhibited dose-dependent vasodilation in response to caffeine and theophylline. Treatment of TEBVs with 1 μM lovastatin for three days prior to addition of Tumor necrosis factor - α (TNF-α) blocked the injury response and maintained vasodilation. These results indicate the potential to develop a rapidly-producible, endothelialized TEBV for microphysiological systems capable of producing physiological responses to both pharmaceutical and immunological stimuli.

  16. Metabolic state alters economic decision making under risk in humans.

    OpenAIRE

    Mkael Symmonds; Julian J Emmanuel; Megan E Drew; Rachel L Batterham; Raymond J Dolan

    2010-01-01

    Background Animals' attitudes to risk are profoundly influenced by metabolic state (hunger and baseline energy stores). Specifically, animals often express a preference for risky (more variable) food sources when below a metabolic reference point (hungry), and safe (less variable) food sources when sated. Circulating hormones report the status of energy reserves and acute nutrient intake to widespread targets in the central nervous system that regulate feeding behaviour, including brain regio...

  17. Brain Lactate Metabolism in Humans With Subarachnoid Hemorrhage

    OpenAIRE

    Oddo M; Levine JM; Frangos S; Maloney-Wilensky E; Carrera E; Daniel RT; Levivier M; Magistretti PJ; LeRoux PD

    2012-01-01

    Abstract BACKGROUND AND PURPOSE: Lactate is central for the regulation of brain metabolism and is an alternative substrate to glucose after injury. Brain lactate metabolism in patients with subarachnoid hemorrhage has not been fully elucidated. METHODS: Thirty one subarachnoid hemorrhage patients monitored with cerebral microdialysis (CMD) and brain oxygen (PbtO(2)) were studied. Samples with elevated CMD lactate (>4 mmol/L) were matched to PbtO(2) and CMD pyruvate and categorized as hypoxi...

  18. Recon3D enables a three-dimensional view of gene variation in human metabolism

    DEFF Research Database (Denmark)

    Brunk, Elizabeth; Sahoo, Swagatika; Zielinski, Daniel C.

    2018-01-01

    Genome-scale network reconstructions have helped uncover the molecular basis of metabolism. Here we present Recon3D, a computational resource that includes three-dimensional (3D) metabolite and protein structure data and enables integrated analyses of metabolic functions in humans. We use Recon3D...

  19. Metabolism of acyclic and cyclic N-nitroamines by cultured human colon

    DEFF Research Database (Denmark)

    Autrup, Herman; Harris, Curtis C.; Trump, Benjamin F.

    1978-01-01

    Cultured human colon mucosa was found to metabolize both acyclic and cyclic N-nitrosamines as measured by 14C-CO2 formation and reaction of the activated moieties with cellular macromolecules. Dimethylnitrosamine and N-nitrosopyrrolidine were metabolized by explants from all patients studied. A p...

  20. Vaccination via Chloroplast Genetics: Affordable Protein Drugs for the Prevention and Treatment of Inherited or Infectious Human Diseases.

    Science.gov (United States)

    Daniell, Henry; Chan, Hui-Ting; Pasoreck, Elise K

    2016-11-23

    Plastid-made biopharmaceuticals treat major metabolic or genetic disorders, including Alzheimer's, diabetes, hypertension, hemophilia, and retinopathy. Booster vaccines made in chloroplasts prevent global infectious diseases, such as tuberculosis, malaria, cholera, and polio, and biological threats, such as anthrax and plague. Recent advances in this field include commercial-scale production of human therapeutic proteins in FDA-approved cGMP facilities, development of tags to deliver protein drugs to targeted human cells or tissues, methods to deliver precise doses, and long-term stability of protein drugs at ambient temperature, maintaining their efficacy. Codon optimization utilizing valuable information from sequenced chloroplast genomes enhanced expression of eukaryotic human or viral genes in chloroplasts and offered unique insights into translation in chloroplasts. Support from major biopharmaceutical companies, development of hydroponic production systems, and evaluation by regulatory agencies, including the CDC, FDA, and USDA, augur well for advancing this novel concept to the clinic and revolutionizing affordable healthcare.

  1. Polymorphism of antimalaria drug metabolizing, nuclear receptor, and drug transport genes among malaria patients in Zanzibar, East Africa.

    Science.gov (United States)

    Ferreira, Pedro Eduardo; Veiga, Maria Isabel; Cavaco, Isa; Martins, J Paulo; Andersson, Björn; Mushin, Shaliya; Ali, Abullah S; Bhattarai, Achuyt; Ribeiro, Vera; Björkman, Anders; Gil, José Pedro

    2008-02-01

    Artemisinin-based combination therapy is a main strategy for malaria control in Africa. Zanzibar introduced this new treatment policy in 2003. The authors have studied the prevalence of a number of functional single nucleotide polymorphisms (SNPs) in genes associated with the elimination of the artemisinin-based combination therapy compounds in use in Zanzibar to investigate the frequencies of subgroups potentially at higher drug exposure and therefore possible higher risk of toxicity. One hundred three unrelated children with uncomplicated malaria from the Unguja and Pemba islands of Zanzibar were enrolled. With use of polymerase chain reaction (PCR)-restriction fragment length polymorphism and real-time PCR-based allele discrimination methods, the CYP2B6 (G15631T), CYP3A4 (A-392G), CYP3A5 (A6986G, G14690A, 27131-132 insT, C3699T) SNPs and MDR1 SNPs C3435T, G2677T/A, and T-129C were analyzed. PCR product sequencing was applied to regulatory regions of MDR1, the CYP3A4 proximal promoter, and to exons 2 and 5 of PXR, a gene coding for a nuclear factor activated by artemisinin antimalarials and associated with the transcription induction of most of the studied genes. Homozygous subjects for alleles coding for low activity proteins were found at the following frequencies: 1) MDR1: 2.9%; 2) CYP2B6: 9.7%; 3) CYP3A5: 14.1%; and 4) CYP3A4: 49.5%. No functionally relevant allele was found in the analyzed regions of PXR. A new MDR1 SNP was found (T-158C), located in a putative antigen recognition element. Ten (10.1%) subjects were predicted to be low metabolizers simultaneously for CYP3A4 and CYP3A5. This fraction of the population is suggested to be under higher exposure to certain antimalarials, including lumefantrine and quinine.

  2. Computational Modeling of Human Metabolism and Its Application to Systems Biomedicine.

    Science.gov (United States)

    Aurich, Maike K; Thiele, Ines

    2016-01-01

    Modern high-throughput techniques offer immense opportunities to investigate whole-systems behavior, such as those underlying human diseases. However, the complexity of the data presents challenges in interpretation, and new avenues are needed to address the complexity of both diseases and data. Constraint-based modeling is one formalism applied in systems biology. It relies on a genome-scale reconstruction that captures extensive biochemical knowledge regarding an organism. The human genome-scale metabolic reconstruction is increasingly used to understand normal cellular and disease states because metabolism is an important factor in many human diseases. The application of human genome-scale reconstruction ranges from mere querying of the model as a knowledge base to studies that take advantage of the model's topology and, most notably, to functional predictions based on cell- and condition-specific metabolic models built based on omics data.An increasing number and diversity of biomedical questions are being addressed using constraint-based modeling and metabolic models. One of the most successful biomedical applications to date is cancer metabolism, but constraint-based modeling also holds great potential for inborn errors of metabolism or obesity. In addition, it offers great prospects for individualized approaches to diagnostics and the design of disease prevention and intervention strategies. Metabolic models support this endeavor by providing easy access to complex high-throughput datasets. Personalized metabolic models have been introduced. Finally, constraint-based modeling can be used to model whole-body metabolism, which will enable the elucidation of metabolic interactions between organs and disturbances of these interactions as either causes or consequence of metabolic diseases. This chapter introduces constraint-based modeling and describes some of its contributions to systems biomedicine.

  3. Effects of model traumatic injury on hepatic drug metabolism in the rat. IV. Glucuronidation.

    Science.gov (United States)

    Griffeth, L K; Rosen, G M; Rauckman, E J

    1985-01-01

    A previously validated small mammal trauma model, hind-limb ischemia secondary to infrarenal aortic ligation in the rat, was utilized to investigate the effects of traumatic injury on hepatic glucuronidation activity. As was previously observed with hepatic oxidative drug metabolism, model trauma resulted in a significant decrease in the in vivo glucuronidation of chloramphenicol, with a 23% drop in clearance of this drug. The effect on in vivo pharmacokinetics appeared to result from a complex interaction between trauma's differential influences on conjugating enzyme(s), deconjugating enzyme(s), and hepatic UDP-glucuronic acid levels, as well as the relative physiological importance of these variables. Hepatic UDP-glucuronyltransferase activities towards both p-nitrophenol and chloramphenicol were elevated (44-54%) after model injury when measured in native hepatic microsomes. However, microsomes which had been "activated" by treatment with Triton X-100 showed no significant difference between control and traumatized animals. Serum beta-glucuronidase activities were elevated by 58%, while hepatic beta-glucuronidase rose by about 16%. Nevertheless, in vivo deconjugation showed no significant change. Model trauma also resulted in a 46% decrease in hepatic UDP-glucuronic acid content. Thus, the observed post-traumatic depression of in vivo chloramphenicol glucuronidation could be due either to a diminished availability of a necessary cofactor (UDP-glucuronic acid) or to an alteration in enzyme kinetics or function in vivo.

  4. Mood stabilizing drugs regulate transcription of immune, neuronal and metabolic pathway genes in Drosophila.

    Science.gov (United States)

    Herteleer, L; Zwarts, L; Hens, K; Forero, D; Del-Favero, J; Callaerts, P

    2016-05-01

    Lithium and valproate (VPA) are drugs used in the management of bipolar disorder. Even though they reportedly act on various pathways, the transcriptional targets relevant for disease mechanism and therapeutic effect remain unclear. Furthermore, multiple studies used lymphoblasts of bipolar patients as a cellular proxy, but it remains unclear whether peripheral cells provide a good readout for the effects of these drugs in the brain. We used Drosophila culture cells and adult flies to analyze the transcriptional effects of lithium and VPA and define mechanistic pathways. Transcriptional profiles were determined for Drosophila S2-cells and adult fly heads following lithium or VPA treatment. Gene ontology categories were identified using the DAVID functional annotation tool with a cut-off of p neuronal development, neuronal function, and metabolism. (i) Transcriptional effects of lithium and VPA in Drosophila S2 cells and heads show significant overlap. (ii) The overlap between transcriptional alterations in peripheral versus neuronal cells at the single gene level is negligible, but at the gene ontology and pathway level considerable overlap can be found. (iii) Lithium and VPA act on evolutionarily conserved pathways in Drosophila and mammalian models.

  5. Metabolic clearance and production rates of human growth hormone

    Science.gov (United States)

    Taylor, Andrew L.; Finster, Joseph L.; Mintz, Daniel H.

    1969-01-01

    The metabolic clearance rate (MCR) of human growth hormone (HGH) was determined by the constant infusion to equilibrium technique utilizing HGH-125I. 22 control subjects had a MCR of 229 ±52 ml/min (mean ±SD). No difference was evident between sexes, or between various age groups. Patients with acromegaly demonstrated normal MCR's. Moreover, acute elevations of plasma growth hormone concentrations in normal subjects did not alter the MCR of HGH. The MCR was relatively constant from day to day and within the day when subjects were evaluated in the supine position. In contrast, the assumption of the upright position was associated with a mean 24% decrease in the MCR. These results were contrasted with the MCR of HGH observed in a small number of patients with altered thyroid function or diabetes mellitus. In six patients with hypothyroidism the MCR (131 ±36 ml/min) was significantly decreased (P < 0.001); whereas the MCR in eight patients with hyperthyroidism (240 ±57 ml/min) did not differ from control subjects. The MCR in eight patients with insulin-independent diabetes mellitus (IID) (185 ±41 ml/min) and in eight patients with insulin-dependent diabetes mellitus (IDD) (136 ±31 ml/min) were significantly different from control subjects (P = < 0.05 and P = < 0.001, respectively). These data were interpreted to indicate that the plasma HGH-removing mechanism(s) is not saturated at physiologic plasma HGH levels, that plasma HGH levels alone may not permit distinction between variations in pituitary release of the hormone and its rate of clearance from the plasma, and that the estimation of the MCR of HGH may help clarify the mechanism of abnormal plasma HGH responses to various stimuli. Production rates of HGH (PR) in control subjects (347 ±173 mμg/min) were contrasted with hyperthyroid patients (529 ±242 mμg/min, P < 0.05), hypothyroid patients (160 ±69 mμg/min, P < 0.02), IID (245 ±100 mμg/min, NS), and IDD (363 ±153 mμg/min, NS). Considerable

  6. International Guidelines on Human Rights and Drug Control: A Tool for Securing Women's Rights in Drug Control Policy.

    Science.gov (United States)

    Schleifer, Rebecca; Pol, Luciana

    2017-06-01

    Discrimination and inequality shape women's experiences of drug use and in the drug trade and the impact of drug control efforts on them, with disproportionate burdens faced by poor and otherwise marginalized women. In recent years, UN member states and UN drug control and human rights entities have recognized this issue and made commitments to integrate a 'gender perspective' into drug control policies, with 'gender' limited to those conventionally deemed women. But the concept of gender in international law is broader, rooted in socially constructed and culturally determined norms and expectations around gender roles, sex, and sexuality. Also, drug control policies often fail to meaningfully address the specific needs and circumstances of women (inclusively defined), leaving them at risk of recurrent violations of their rights in the context of drugs. This article explores what it means to 'mainstream' this narrower version of gender into drug control efforts, using as examples various women's experiences as people who use drugs, in the drug trade, and in the criminal justice system. It points to international guidelines on human rights and drug control as an important tool to ensure attention to women's rights in drug control policy design and implementation.

  7. Identification of the Consistently Altered Metabolic Targets in Human Hepatocellular Carcinoma.

    Science.gov (United States)

    Nwosu, Zeribe Chike; Megger, Dominik Andre; Hammad, Seddik; Sitek, Barbara; Roessler, Stephanie; Ebert, Matthias Philip; Meyer, Christoph; Dooley, Steven

    2017-09-01

    Cancer cells rely on metabolic alterations to enhance proliferation and survival. Metabolic gene alterations that repeatedly occur in liver cancer are largely unknown. We aimed to identify metabolic genes that are consistently deregulated, and are of potential clinical significance in human hepatocellular carcinoma (HCC). We studied the expression of 2,761 metabolic genes in 8 microarray datasets comprising 521 human HCC tissues. Genes exclusively up-regulated or down-regulated in 6 or more datasets were defined as consistently deregulated. The consistent genes that correlated with tumor progression markers ( ECM2 and MMP9) (Pearson correlation P < .05) were used for Kaplan-Meier overall survival analysis in a patient cohort. We further compared proteomic expression of metabolic genes in 19 tumors vs adjacent normal liver tissues. We identified 634 consistent metabolic genes, ∼60% of which are not yet described in HCC. The down-regulated genes (n = 350) are mostly involved in physiologic hepatocyte metabolic functions (eg, xenobiotic, fatty acid, and amino acid metabolism). In contrast, among consistently up-regulated metabolic genes (n = 284) are those involved in glycolysis, pentose phosphate pathway, nucleotide biosynthesis, tricarboxylic acid cycle, oxidative phosphorylation, proton transport, membrane lipid, and glycan metabolism. Several metabolic genes (n = 434) correlated with progression markers, and of these, 201 predicted overall survival outcome in the patient cohort analyzed. Over 90% of the metabolic targets significantly altered at the protein level were similarly up- or down-regulated as in genomic profile. We provide the first exposition of the consistently altered metabolic genes in HCC and show that these genes are potentially relevant targets for onward studies in preclinical and clinical contexts.

  8. Evaluation of Human Adipose Tissue Stromal Heterogeneity in Metabolic Disease Using Single Cell RNA-Seq

    Science.gov (United States)

    2017-09-01

    AWARD NUMBER: W81XWH-15-1-0251 TITLE: “Evaluation of Human Adipose Tissue Stromal Heterogeneity in Metabolic Disease Using Single Cell RNA...Heterogeneity in Metabolic Disease Using Single- Cell RNA-Seq 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Linus Tzu-Yen...ABSTRACT We have developed a robust protocol to generate single cell transcriptional profiles from subcutaneous adipose tissue samples of both human

  9. Acute encephalopathy with concurrent respiratory and metabolic disturbances in first known parenteral human administration of flunixin meglumine and acepromazine maleate.

    Science.gov (United States)

    Kamali, Michael F; Wilson, Anwar C; Acquisto, Nicole M; Spillane, Linda; Schneider, Sandra M

    2013-08-01

    Flunexin is a nonsteroidal anti-inflammatory drug approved for veterinary use in horses and cattle. Acepromazine is a phenothiazine derivative used in horses, dogs, and cats. Human exposure to these substances is rare. We report a case of a human injection of two equine medications, flunixin and acepromazine, which resulted in altered mental status, respiratory alkalosis, gastrointestinal bleeding, and elevation of liver transaminases in a 43-year-old woman who worked as a horse trainer. The patient intentionally self-injected these medications and subsequently presented to the Emergency Department with altered mental status and lethargy. The patient required hospitalization for metabolic abnormalities, including respiratory alkalosis, and suffered a gastrointestinal bleed requiring blood transfusion. The patient ultimately recovered with supportive measures. We believe this to be the first case of concomitant injection of flunixin and acepromazine in a human. This report explains a case of parenteral administration of two equine medications and the subsequent complications in a patient that presented to the Emergency Department. Human exposure to veterinary medications cannot be predicted by their effect in animals due to variations in absorption, distribution, and metabolism. Physicians should be aware that individuals who work with animals may have access to large quantities of veterinary medicine. This case also exemplifies the challenges that Emergency Physicians face on a daily basis, and generates additional consideration for overdoses and intoxications from medications that are not considered commonplace in humans. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Metabolic mapping of the brain's response to visual stimulation: studies in humans

    International Nuclear Information System (INIS)

    Phelps, M.E.; Kuhl, D.E.; Mazziotta, J.C.

    1981-01-01

    These studies demonstrated increasing glucose metabolic rates in the human primary (PVC) and associative (AVC) visual cortex as the complexity of visual scenes increased. The metabolic response of the AVC increased more rapidly with scene complexity than that of the PVC, indicating the greater involvement of the higher order AVC for complex visual interpretations. Increases in local metabolic activity by as much as a factor of 2 above that of control subjects with eyes closed indicate the wide range and metabolic reserve of the visual cortex

  11. First-pass metabolism of ethanol in human beings: effect of intravenous infusion of fructose

    DEFF Research Database (Denmark)

    Parlesak, Alexandr; Billinger, MH; Schäfer, C.

    2004-01-01

    Intravenous infusion of fructose has been shown to enhance reduced form of nicotinamide adenine dinucleotide reoxidation and, thereby, to enhance the metabolism of ethanol. In the current study, the effect of fructose infusion on first-pass metabolism of ethanol was studied in human volunteers....... A significantly higher first-pass metabolism of ethanol was obtained after administration of fructose in comparison with findings for control experiments with an equimolar dose of glucose. Because fructose is metabolized predominantly in the liver and can be presumed to have virtually no effects in the stomach...

  12. Annual banned-substance review: analytical approaches in human sports drug testing.

    Science.gov (United States)

    Thevis, Mario; Kuuranne, Tiia; Walpurgis, Katja; Geyer, Hans; Schänzer, Wilhelm

    2016-01-01

    The aim of improving anti-doping efforts is predicated on several different pillars, including, amongst others, optimized analytical methods. These commonly result from exploiting most recent developments in analytical instrumentation as well as research data on elite athletes' physiology in general, and pharmacology, metabolism, elimination, and downstream effects of prohibited substances and methods of doping, in particular. The need for frequent and adequate adaptations of sports drug testing procedures has been incessant, largely due to the uninterrupted emergence of new chemical entities but also due to the apparent use of established or even obsolete drugs for reasons other than therapeutic means, such as assumed beneficial effects on endurance, strength, and regeneration capacities. Continuing the series of annual banned-substance reviews, literature concerning human sports drug testing published between October 2014 and September 2015 is summarized and reviewed in reference to the content of the 2015 Prohibited List as issued by the World Anti-Doping Agency (WADA), with particular emphasis on analytical approaches and their contribution to enhanced doping controls. Copyright © 2016 John Wiley & Sons, Ltd.

  13. A reduced cerebral metabolic ratio in exercise reflects metabolism and not accumulation of lactate within the human brain

    DEFF Research Database (Denmark)

    Dalsgaard, Mads K; Quistorff, Bjørn; Danielsen, Else R

    2003-01-01

    During maximal exercise lactate taken up by the human brain contributes to reduce the cerebral metabolic ratio, O(2)/(glucose + 1/2 lactate), but it is not known whether the lactate is metabolized or if it accumulates in a distribution volume. In one experiment the cerebral arterio-venous differe......During maximal exercise lactate taken up by the human brain contributes to reduce the cerebral metabolic ratio, O(2)/(glucose + 1/2 lactate), but it is not known whether the lactate is metabolized or if it accumulates in a distribution volume. In one experiment the cerebral arterio......-venous differences (AV) for O(2), glucose (glc) and lactate (lac) were evaluated in nine healthy subjects at rest and during and after exercise to exhaustion. The cerebrospinal fluid (CSF) was drained through a lumbar puncture immediately after exercise, while control values were obtained from six other healthy.......0 to 0.9 +/- 0.1 mM (P ratio from 6.0 +/- 0.3 to 2.8 +/- 0.2 (P

  14. Mass balance, metabolic disposition, and pharmacokinetics of a single oral dose of regorafenib in healthy human subjects.

    Science.gov (United States)

    Gerisch, Michael; Hafner, Frank-Thorsten; Lang, Dieter; Radtke, Martin; Diefenbach, Konstanze; Cleton, Adriaan; Lettieri, John

    2018-01-01

    To evaluate the mass balance, metabolic disposition, and pharmacokinetics of a single dose of regorafenib in healthy volunteers. In addition, in vitro metabolism of regorafenib in human hepatocytes was investigated. Four healthy male subjects received one 120 mg oral dose of regorafenib containing approximately 100 µCi (3.7 MBq) [ 14 C]regorafenib. Plasma concentrations of parent drug were derived from HPLC-MS/MS analysis and total radioactivity from liquid scintillation counting (LSC). Radiocarbon analyses used HPLC with fraction collection followed by LSC for all urine samples, plasma, and fecal homogenate extracts. For the in vitro study, [ 14 C]regorafenib was incubated with human hepatocytes and analyzed using HPLC-LSC and HPLC-HRMS/MS. Regorafenib was the major component in plasma, while metabolite M-2 (pyridine N-oxide) was the most prominent metabolite. Metabolites M-5 (demethylated pyridine N-oxide) and M-7 (N-glucuronide) were identified as minor plasma components. The mean concentration of total radioactivity in plasma/whole blood appeared to plateau at 1-4 h and again at 6-24 h post-dose. In total, 90.5% of administered radioactivity was recovered in the excreta within a collection interval of 12 days, most of which (71.2%) was eliminated in feces, while excretion via urine accounted for 19.3%. Regorafenib (47.2%) was the most prominent component in feces and was not excreted into urine. Excreted metabolites resulted from oxidative metabolism and glucuronidation. Regorafenib was eliminated predominantly in feces as well as by hepatic biotransformation. The multiple biotransformation pathways of regorafenib decrease the risk of pharmacokinetic drug-drug interactions.

  15. A global evolutionary and metabolic analysis of human obesity gene risk variants.

    Science.gov (United States)

    Castillo, Joseph J; Hazlett, Zachary S; Orlando, Robert A; Garver, William S

    2017-09-05

    It is generally accepted that the selection of gene variants during human evolution optimized energy metabolism that now interacts with our obesogenic environment to increase the prevalence of obesity. The purpose of this study was to perform a global evolutionary and metabolic analysis of human obesity gene risk variants (110 human obesity genes with 127 nearest gene risk variants) identified using genome-wide association studies (GWAS) to enhance our knowledge of early and late genotypes. As a result of determining the mean frequency of these obesity gene risk variants in 13 available populations from around the world our results provide evidence for the early selection of ancestral risk variants (defined as selection before migration from Africa) and late selection of derived risk variants (defined as selection after migration from Africa). Our results also provide novel information for association of these obesity genes or encoded proteins with diverse metabolic pathways and other human diseases. The overall results indicate a significant differential evolutionary pattern for the selection of obesity gene ancestral and derived risk variants proposed to optimize energy metabolism in varying global environments and complex association with metabolic pathways and other human diseases. These results are consistent with obesity genes that encode proteins possessing a fundamental role in maintaining energy metabolism and survival during the course of human evolution. Copyright © 2017. Published by Elsevier B.V.

  16. Metabolic Control Analysis aimed at the ribose synthesis pathways of tumor cells: a new strategy for antitumor drug development

    NARCIS (Netherlands)

    Boren, Joan; Montoya, Antonio Ramos; de Atauri, Pedro; Comin-Anduix, Begoña; Cortes, Antonio; Centelles, Josep J.; Frederiks, Wilma M.; van Noorden, Cornelis J. F.; Cascante, Marta

    2002-01-01

    Metabolic control analysis predicts that effects on tumor growth are likely to be obtained with lower concentrations of drug, if an enzyme with a high control coefficient on tumor growth is being inhibited. Here we measure glucose-6-phosphate dehydrogenase (G6PDH) control coefficient on in vivo

  17. Carboxylesterase 1A2 encoding gene with increased transcription and potential rapid drug metabolism in Asian populations

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Madsen, Majbritt Busk; Lyauk, Yassine Kamal

    2017-01-01

    The carboxylesterase 1 gene (CES1) encodes a hydrolase implicated in the metabolism of commonly used drugs. CES1A2, a hybrid of CES1 and a CES1-like pseudogene, has a promoter that is weak in most individuals. However, some individuals harbor a promoter haplotype of this gene with two overlapping...

  18. Protein metabolism in the rat cerebral cortex in vivo and in vitro as affected by the acquisition enhancing drug piracetam

    NARCIS (Netherlands)

    Nickolson, V.J.; Wolthuis, O.L.

    1976-01-01

    The effect of Piracetam on rat cerebral protein metabolism in vivo and in vitro was studied. It was found that the drug stimulates the uptake of labelled leucine by cerebral cortex slices, has no effect on the incorporation of leucine into cerebral protein, neither in slices nor in vivo, but

  19. Sex differences of human cortical blood flow and energy metabolism

    DEFF Research Database (Denmark)

    Aanerud, Joel; Borghammer, Per; Rodell, Anders

    2017-01-01

    cerebral blood flow and cerebral metabolic rate of oxygen as functions of age in healthy volunteers of both sexes. Cerebral metabolic rate of oxygen did not change with age for either sex and there were no differences of mean values of cerebral metabolic rate of oxygen between men and women in cerebral...... cortex. Women had significant decreases of cerebral blood flow as function of age in frontal and parietal lobes. Young women had significantly higher cerebral blood flow than men in frontal and temporal lobes, but these differences had disappeared at age 65. The absent sex difference of cerebral energy...... turnover suggests that the known differences of synaptic density between the sexes are counteracted by opposite differences of individual synaptic activity....

  20. Metabolism

    Science.gov (United States)

    ... lin), which signals cells to increase their anabolic activities. Metabolism is a complicated chemical process, so it's not ... how those enzymes or hormones work. When the metabolism of body chemicals is ... Hyperthyroidism (pronounced: hi-per-THIGH-roy-dih-zum). Hyperthyroidism ...

  1. Potent human uric acid transporter 1 inhibitors: in vitro and in vivo metabolism and pharmacokinetic studies

    Directory of Open Access Journals (Sweden)

    Wempe MF

    2012-11-01

    Full Text Available Michael F Wempe,1 Janet W Lightner,2 Bettina Miller,1 Timothy J Iwen,1 Peter J Rice,1 Shin Wakui,3 Naohiko Anzai,4 Promsuk Jutabha,4 Hitoshi Endou51Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; 2Department of Pharmacology, East Tennessee State University, Johnson City, TN, USA; 3Department of Toxicology, Azabu University School of Veterinary Medicine, Chuo Sagamihara, Kanagawa, Japan; 4Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu, Shimotsuga, Tochigi, Japan; 5Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, JapanAbstract: Human uric acid transporter 1 (hURAT1; SLC22A12 is a very important urate anion exchanger. Elevated urate levels are known to play a pivotal role in cardiovascular diseases, chronic renal disease, diabetes, and hypertension. Therefore, the development of potent uric acid transport inhibitors may lead to novel therapeutic agents to combat these human diseases. The current study investigates small molecular weight compounds and their ability to inhibit 14C-urate uptake in oocytes expressing hURAT1. Using the most promising drug candidates generated from our structure–activity relationship findings, we subsequently conducted in vitro hepatic metabolism and pharmacokinetic (PK studies in male Sprague-Dawley rats. Compounds were incubated with rat liver microsomes containing cofactors nicotinamide adenine dinucleotide phosphate and uridine 5'-diphosphoglucuronic acid. In vitro metabolism and PK samples were analyzed using liquid chromatography/mass spectrometry-mass spectrometry methods. Independently, six different inhibitors were orally (capsule dosing or intravenously (orbital sinus administered to fasting male Sprague-Dawley rats. Blood samples were collected and analyzed; these data were used to compare in vitro and in vivo metabolism and to

  2. 75 FR 45130 - Guidance for Industry and Researchers on the Radioactive Drug Research Committee: Human Research...

    Science.gov (United States)

    2010-08-02

    ... and Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, rm. 2201, Silver... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2009-D-0125] Guidance for Industry and Researchers on the Radioactive Drug Research Committee: Human Research Without an...

  3. Controlled delivery of antiangiogenic drug to human eye tissue using a MEMS device

    KAUST Repository

    Pirmoradi, Fatemeh Nazly; Ou, Kevin; Jackson, John K.; Letchford, Kevin; Cui, Jing; Wolf, Ki Tae; Graber, Florian; Zhao, Tom; Matsubara, Joanne A.; Burt, Helen; Chiao, Mu; Lin, Liwei

    2013-01-01

    We demonstrate an implantable MEMS drug delivery device to conduct controlled and on-demand, ex vivo drug transport to human eye tissue. Remotely operated drug delivery to human post-mortem eyes was performed via a MEMS device. The developed curved

  4. Drugs associated with teratogenic mechanisms. Part II : a literature review of the evidence on human risks

    NARCIS (Netherlands)

    van Gelder, Marleen M. H. J.; de Jong-van den Berg, Lolkje T. W.; Roeleveld, Nel

    What is the current state of knowledge on the human risks of drugs suspected to be associated with teratogenic mechanisms? Evidence for the presence or absence of human risks of birth defects is scarce or non-existent for the majority of drugs associated with teratogenic mechanisms. Medical drugs

  5. SPIN1, negatively regulated by miR-148/152, enhances Adriamycin resistance via upregulating drug metabolizing enzymes and transporter in breast cancer.

    Science.gov (United States)

    Chen, Xu; Wang, Ya-Wen; Gao, Peng

    2018-05-09

    Spindlin1 (SPIN1), a protein highly expressed in several human cancers, has been correlated with tumorigenesis and development. Alterations of drug metabolizing enzymes and drug transporters are major determinants of chemoresistance in tumor cells. However, whether the metabolizing enzymes and transporters are under the control of SPIN1 in breast cancer chemoresistance has not yet been defined. SPIN1 expression in breast cancer cells and tissues was detected by quantitative real-time PCR (qRT-PCR) and immunohistochemistry. Chemosensitivity assays in vitro and in vivo were performed to determine the effect of SPIN1 on Adriamycin resistance. Downstream effectors of SPIN1 were screened by microarray and confirmed by qRT-PCR and Western blot. Luciferase assay and Western blot were used to identify miRNAs regulating SPIN1. We showed that SPIN1 was significantly elevated in drug-resistant breast cancer cell lines and tissues, compared with the chemosensitive ones. SPIN1 enhanced Adriamycin resistance of breast cancer cells in vitro, and downregulation of SPIN1 by miRNA could decrease Adriamycin resistance in vivo. Mechanistically, drug metabolizing enzymes and transporter CYP2C8, UGT2B4, UGT2B17 and ABCB4 were proven to be downstream effectors of SPIN1. Notably, SPIN1 was identified as a direct target of the miR-148/152 family (miR-148a-3p, miR-148b-3p and miR-152-3p). As expected, miR-148a-3p, miR-148b-3p or miR-152-3p could increase Adriamycin sensitivity in breast cancer cells in vitro. Moreover, high expression of SPIN1 or low expression of the miR-148/152 family predicted poorer survival in breast cancer patients. Our results establish that SPIN1, negatively regulated by the miR-148/152 family, enhances Adriamycin resistance in breast cancer via upregulating the expression of drug metabolizing enzymes and drug transporter.

  6. Mechanistic modeling of aberrant energy metabolism in human disease

    Directory of Open Access Journals (Sweden)

    Vineet eSangar

    2012-10-01

    Full Text Available Dysfunction in energy metabolism—including in pathways localized to the mitochondria—has been implicated in the pathogenesis of a wide array of disorders, ranging from cancer to neurodegenerative diseases to type II diabetes. The inherent complexities of energy and mitochondrial metabolism present a significant obstacle in the effort to understand the role that these molecular processes play in the development of disease. To help unravel these complexities, systems biology methods have been applied to develop an array of computational metabolic models, ranging from mitochondria-specific processes to genome-scale cellular networks. These constraint-based models can efficiently simulate aspects of normal and aberrant metabolism in various genetic and environmental conditions. Development of these models leverages—and also provides a powerful means to integrate and interpret—information from a wide range of sources including genomics, proteomics, metabolomics, and enzyme kinetics. Here, we review a variety of mechanistic modeling studies that explore metabolic functions, deficiency disorders, and aberrant biochemical pathways in mitochondria and related regions in the cell.

  7. Quantifying interictal metabolic activity in human temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Henry, T.R.; Mazziotta, J.C.; Engel, J. Jr.; Christenson, P.D.; Zhang, J.X.; Phelps, M.E.; Kuhl, D.E.

    1990-01-01

    The majority of patients with complex partial seizures of unilateral temporal lobe origin have interictal temporal hypometabolism on [18F]fluorodeoxyglucose positron emission tomography (FDG PET) studies. Often, this hypometabolism extends to ipsilateral extratemporal sites. The use of accurately quantified metabolic data has been limited by the absence of an equally reliable method of anatomical analysis of PET images. We developed a standardized method for visual placement of anatomically configured regions of interest on FDG PET studies, which is particularly adapted to the widespread, asymmetric, and often severe interictal metabolic alterations of temporal lobe epilepsy. This method was applied by a single investigator, who was blind to the identity of subjects, to 10 normal control and 25 interictal temporal lobe epilepsy studies. All subjects had normal brain anatomical volumes on structural neuroimaging studies. The results demonstrate ipsilateral thalamic and temporal lobe involvement in the interictal hypometabolism of unilateral temporal lobe epilepsy. Ipsilateral frontal, parietal, and basal ganglial metabolism is also reduced, although not as markedly as is temporal and thalamic metabolism

  8. Regulation of Metabolic Signaling in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Albers, Peter Hjorth

    sensitivity in type I muscle fibers possibly reflects a superior effect of insulin on metabolic signaling compared to type II muscle fibers. This was investigated in the present thesis by examining muscle biopsies from lean and obese healthy subjects as well as patients with type 2 diabetes. From these muscle...

  9. Sex differences of human cortical blood flow and energy metabolism.

    Science.gov (United States)

    Aanerud, Joel; Borghammer, Per; Rodell, Anders; Jónsdottir, Kristjana Y; Gjedde, Albert

    2017-07-01

    Brain energy metabolism is held to reflect energy demanding processes in neuropil related to the density and activity of synapses. There is recent evidence that men have higher density of synapses in temporal cortex than women. One consequence of these differences would be different rates of cortical energy turnover and blood flow in men and women. To test the hypotheses that rates of oxygen consumption (CMRO 2 ) and cerebral blood flow are higher in men than in women in regions of cerebral cortex, and that the differences persist with aging, we used positron emission tomography to determine cerebral blood flow and cerebral metabolic rate of oxygen as functions of age in healthy volunteers of both sexes. Cerebral metabolic rate of oxygen did not change with age for either sex and there were no differences of mean values of cerebral metabolic rate of oxygen between men and women in cerebral cortex. Women had significant decreases of cerebral blood flow as function of age in frontal and parietal lobes. Young women had significantly higher cerebral blood flow than men in frontal and temporal lobes, but these differences had disappeared at age 65. The absent sex difference of cerebral energy turnover suggests that the known differences of synaptic density between the sexes are counteracted by opposite differences of individual synaptic activity.

  10. CHANGING METABOLIC FUNCTIONS IN EXPERIMENTAL ANIMALS AFTER INTRODUCTION OF THE XENOBIOTIC, IMMUNOTROPIC DRUG AND PROBIOTIC

    Directory of Open Access Journals (Sweden)

    Zvyagintseva O.V.

    2015-05-01

    Full Text Available The aim of the study was to evaluate in vivo changes in metabolic and barrier function of the resistance factors (activity of enzymes of neutrophils, the efficiency of phagocytosis, some biochemical parameters (concentration of ceruloplasmin and haptoglobin and proliferate activity in vitro cells after introduction of copper sulfate, probiotics and immunostimulant "Fungidol" the experimental animals. Material and methods. The in vivo experiments were performed on 6-month-old male rats of Wistar line. Identified the following groups: group 1 - control animals, which were intraperitoneally injected with saline (n = 5; group 2 - animals that were administered saline per os and 48 hours a solution of copper sulphate intraperitoneally (n = 5; group 3 - animals, which were injected with immunotropic drug "Fungidol" per os and 48 hours a solution of copper sulphate intraperitoneally (n = 5; group 4 animals, which were injected with a solution of probiotics per os and 48 hours a solution of copper sulphate intraperitoneally (n = 5. As a probiotic used capsules firm Yogurt that contains active Lactobacillus acidophilus, Lactobacillus rhamnosus, Streptococcus thermophillus, Lactobacillus bulgaricus. The concentration of haptoglobin and ceruloplasmin were determined spectrophotometrically. Oxygen-dependent metabolism of neutrophils was investigated by microscopy according to their ability to absorb nitroblue tetrazolium (NBT-test and restore it to deformazione in the form of granules blue color under the influence of superoxide anion, which is formed in the NADP-oxidase reaction, initiating the process of stimulation of phagocytosis (NBT-test. To determine the barrier function of phagocytic cells by light microscopy to evaluate the activity of phagocytosis of neutrophilic granulocytes with subsequent determination of phagocytic index, phagocytic number and the index of completeness of phagocytosis. As a microbial agent used is a suspension culture of

  11. The human hepatocyte cell lines IHH and HepaRG : models to study glucose, lipid and lipoprotein metabolism

    NARCIS (Netherlands)

    Samanez, Carolina Huaman; Caron, Sandrine; Briand, Olivier; Dehondt, Helene; Duplan, Isabelle; Kuipers, Folkert; Hennuyer, Nathalie; Clavey, Veronique; Staels, Bart

    Metabolic diseases reach epidemic proportions. A better knowledge of the associated alterations in the metabolic pathways in the liver is necessary. These studies need in vitro human cell models. Several human hepatoma models are used, but the response of many metabolic pathways to physiological

  12. Increased circulating full-length betatrophin levels in drug-naïve metabolic syndrome.

    Science.gov (United States)

    Liu, Dan; Li, Sheyu; He, He; Yu, Chuan; Li, Xiaodan; Liang, Libo; Chen, Yi; Li, Jianwei; Li, Jianshu; Sun, Xin; Tian, Haoming; An, Zhenmei

    2017-03-14

    Betatrophin is a newly identified circulating adipokine playing a role in the regulation of glucose homeostasis and lipid metabolism. But its role in metabolic syndrome (MetS) remains unknown. Therefore, we aimed to compare the circulating betatrophin concentrations between patients with MetS and healthy controls. We recruited 47 patients with MetS and 47 age and sex matched healthy controls. Anthropometric and biochemical measurements were performed, and serum betatrophin levels were detected by ELISA. Full-length betatrophin levels in patients with MetS were significantly higher than those in controls (694.84 ± 365.51 pg/ml versus 356.64 ± 287.92 pg/ml; P <0.001). While no significant difference of total betatrophin levels was found between the two groups (1.20 ± 0.79 ng/ml versus 1.31 ± 1.08 ng/ml; P = 0.524). Full-length betatrophin level was positively correlated with fasting plasma glucose (FPG) (r = 0.357, P = 0.014) and 2-hour plasma glucose (2hPG) (r = 0.38, P <0.01). Binary logistic regression models indicated that subjects in the tertile of the highest full-length betatrophin level experienced higher odds of having MetS (OR, 8.6; 95% CI 2.8-26.8; P <0.001). Our study showed that full-length betatrophin concentrations were increased in drug-naïve MetS patients.

  13. Characterization of energy and neurotransmitter metabolism in cortical glutamatergic neurons derived from human induced pluripotent stem cells: A novel approach to study metabolism in human neurons.

    Science.gov (United States)

    Aldana, Blanca I; Zhang, Yu; Lihme, Maria Fog; Bak, Lasse K; Nielsen, Jørgen E; Holst, Bjørn; Hyttel, Poul; Freude, Kristine K; Waagepetersen, Helle S

    2017-06-01

    Alterations in the cellular metabolic machinery of the brain are associated with neurodegenerative disorders such as Alzheimer's disease. Novel human cellular disease models are essential in order to study underlying disease mechanisms. In the present study, we characterized major metabolic pathways in neurons derived from human induced pluripotent stem cells (hiPSC). With this aim, cultures of hiPSC-derived neurons were incubated with [U- 13 C]glucose, [U- 13 C]glutamate or [U- 13 C]glutamine. Isotopic labeling in metabolites was determined using gas chromatography coupled to mass spectrometry, and cellular amino acid content was quantified by high-performance liquid chromatography. Additionally, we evaluated mitochondrial function using real-time assessment of oxygen consumption via the Seahorse XF e 96 Analyzer. Moreover, in order to validate the hiPSC-derived neurons as a model system, a metabolic profiling was performed in parallel in primary neuronal cultures of mouse cerebral cortex and cerebellum. These serve as well-established models of GABAergic and glutamatergic neurons, respectively. The hiPSC-derived neurons were previously characterized as being forebrain-specific cortical glutamatergic neurons. However, a comparable preparation of predominantly mouse cortical glutamatergic neurons is not available. We found a higher glycolytic capacity in hiPSC-derived neurons compared to mouse neurons and a substantial oxidative metabolism through the mitochondrial tricarboxylic acid (TCA) cycle. This finding is supported by the extracellular acidification and oxygen consumption rates measured in the cultured human neurons. [U- 13 C]Glutamate and [U- 13 C]glutamine were found to be efficient energy substrates for the neuronal cultures originating from both mice and humans. Interestingly, isotopic labeling in metabolites from [U- 13 C]glutamate was higher than that from [U- 13 C]glutamine. Although the metabolic profile of hiPSC-derived neurons in vitro was

  14. Prediction of Human Drug Targets and Their Interactions Using Machine Learning Methods: Current and Future Perspectives.

    Science.gov (United States)

    Nath, Abhigyan; Kumari, Priyanka; Chaube, Radha

    2018-01-01

    Identification of drug targets and drug target interactions are important steps in the drug-discovery pipeline. Successful computational prediction methods can reduce the cost and time demanded by the experimental methods. Knowledge of putative drug targets and their interactions can be very useful for drug repurposing. Supervised machine learning methods have been very useful in drug target prediction and in prediction of drug target interactions. Here, we describe the details for developing prediction models using supervised learning techniques for human drug target prediction and their interactions.

  15. Oxcarbazepine-induced cytotoxicity and genotoxicity in human lymphocyte cultures with or without metabolic activation.

    Science.gov (United States)

    Atlı Şekeroğlu, Zülal; Kefelioğlu, Haluk; Kontaş Yedier, Seval; Şekeroğlu, Vedat; Delmecioğlu, Berrin

    2017-03-01

    There has been considerable debate about the relationship between epilepsy and cancer. Oxcarbazepine (OXC) is used for treating certain types of seizures in patients with epilepsy. There have been no detailed investigations about genotoxicity of OXC and its metabolites. Therefore, the aim of this study is to investigate the cytotoxic and genotoxic effects of OXC and its metabolites on cultured human lymphocytes. The cytotoxicity and genotoxicity of OXC on human peripheral blood lymphocytes were examined in vitro by sister chromatid exchange (SCE), chromosomal aberration (CA) and micronucleus (MN) tests. Cultures were treated with 125, 250 and 500 μg/ml of OXC in the presence (3 h treatment) and absence (24 h and 48 h treatment) of a metabolic activator (S9 mix). Dimethyl sulfoxide (DMSO) was used as a solvent control. OXC showed cytotoxic activities due to significant decreases in mitotic index (MI), proliferation index (PI) and nuclear division index (NDI) in the absence of S9 mix when compared with solvent control. Metabolites of OXC also significantly reduced MI and PI in cultures with S9 mix. OXC significantly increased the CAs, aberrant cells, SCE and MN values in the presence and absence of S9 mix. Our results indicated that both OXC and its metabolites have cytotoxic, cytostatic and genotoxic potential on human peripheral blood lymphocyte cultures under the experimental conditions. Further studies are necessary to elucidate the relationship between cytotoxic, cytostatic and genotoxic effects, and to make a possible risk assessment in patients receiving therapy with this drug.

  16. Reconstruction and Analysis of Human Kidney-Specific Metabolic Network Based on Omics Data

    Directory of Open Access Journals (Sweden)

    Ai-Di Zhang

    2013-01-01

    Full Text Available With the advent of the high-throughput data production, recent studies of tissue-specific metabolic networks have largely advanced our understanding of the metabolic basis of various physiological and pathological processes. However, for kidney, which plays an essential role in the body, the available kidney-specific model remains incomplete. This paper reports the reconstruction and characterization of the human kidney metabolic network based on transcriptome and proteome data. In silico simulations revealed that house-keeping genes were more essential than kidney-specific genes in maintaining kidney metabolism. Importantly, a total of 267 potential metabolic biomarkers for kidney-related diseases were successfully explored using this model. Furthermore, we found that the discrepancies in metabolic processes of different tissues are directly corresponding to tissue's functions. Finally, the phenotypes of the differentially expressed genes in diabetic kidney disease were characterized, suggesting that these genes may affect disease development through altering kidney metabolism. Thus, the human kidney-specific model constructed in this study may provide valuable information for the metabolism of kidney and offer excellent insights into complex kidney diseases.

  17. Drugs to foster kidney regeneration in experimental animals and humans.

    Science.gov (United States)

    Gagliardini, Elena; Benigni, Ariela

    2014-01-01

    The incidence of kidney diseases is increasing worldwide and they are emerging as a major public health problem. Once mostly considered inexorable, renal disease progression can now be halted and lesions can even regress with drugs such as angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II type I receptor blockers, indicating the possibility of kidney repair. The discovery of renal progenitor cells lining the Bowman capsule of adult rat and human kidneys has shed light on the mechanism of repair by ACEi. Parietal progenitors are a reservoir of cells that contribute to podocyte turnover in physiological conditions. In the early phases of renal disease these progenitors migrate chaotically and subsequently proliferate, accumulating in Bowman's space. The abnormal behavior of parietal progenitors is sustained by the activation of CXCR4 receptors in response to an increased production of the chemokine SDF-1 by podocytes activated by the inflammatory environment. Ang II, via the AT1 receptor, also contributes to progenitor cell proliferation. The CXCR4/SDF-1 and Ang II/AT1 receptor pathogenic pathways both pave the way for lesion formation and subsequent sclerosis. ACEi normalize the CXCR4 and AT1 receptor expression on progenitors, limiting their proliferation, concomitant with the regression of hyperplastic lesions in animals, and in a patient with crescentic glomerulopathy. Understanding the molecular and cellular determinants of regeneration triggered by renoprotective drugs will reveal novel pathways that might be challenged or targeted by pharmacological therapy. © 2014 S. Karger AG, Basel.

  18. The metabolic cost of human running: is swinging the arms worth it?

    Science.gov (United States)

    Arellano, Christopher J; Kram, Rodger

    2014-07-15

    Although the mechanical function is quite clear, there is no consensus regarding the metabolic benefit of arm swing during human running. We compared the metabolic cost of running using normal arm swing with the metabolic cost of running while restricting the arms in three different ways: (1) holding the hands with the arms behind the back in a relaxed position (BACK), (2) holding the arms across the chest (CHEST) and (3) holding the hands on top of the head (HEAD). We hypothesized that running without arm swing would demand a greater metabolic cost than running with arm swing. Indeed, when compared with running using normal arm swing, we found that net metabolic power demand was 3, 9 and 13% greater for the BACK, CHEST and HEAD conditions, respectively (all Prunning without arm swing, subjects significantly increased the peak-to-peak amplitudes of both shoulder and pelvis rotation about the vertical axis, most likely a compensatory strategy to counterbalance the rotational angular momentum of the swinging legs. In conclusion, our findings support our general hypothesis that swinging the arms reduces the metabolic cost of human running. Our findings also demonstrate that arm swing minimizes torso rotation. We infer that actively swinging the arms provides both metabolic and biomechanical benefits during human running. © 2014. Published by The Company of Biologists Ltd.

  19. Metabolic signatures of cultured human adipocytes from metabolically healthy versus unhealthy obese individuals.

    Directory of Open Access Journals (Sweden)

    Anja Böhm

    Full Text Available Among obese subjects, metabolically healthy and unhealthy obesity (MHO/MUHO can be differentiated: the latter is characterized by whole-body insulin resistance, hepatic steatosis, and subclinical inflammation. Aim of this study was, to identify adipocyte-specific metabolic signatures and functional biomarkers for MHO versus MUHO.10 insulin-resistant (IR vs. 10 insulin-sensitive (IS non-diabetic morbidly obese (BMI >40 kg/m2 Caucasians were matched for gender, age, BMI, and percentage of body fat. From subcutaneous fat biopsies, primary preadipocytes were isolated and differentiated to adipocytes in vitro. About 280 metabolites were investigated by a targeted metabolomic approach intracellularly, extracellularly, and in plasma.Among others, aspartate was reduced intracellularly to one third (p = 0.0039 in IR adipocytes, pointing to a relative depletion of citric acid cycle metabolites or reduced aspartate uptake in MUHO. Other amino acids, already known to correlate with diabetes and/or obesity, were identified to differ between MUHO's and MHO's adipocytes, namely glutamine, histidine, and spermidine. Most species of phosphatidylcholines (PCs were lower in MUHO's extracellular milieu, though simultaneously elevated intracellularly, e.g., PC aa C32∶3, pointing to increased PC synthesis and/or reduced PC release. Furthermore, altered arachidonic acid (AA metabolism was found: 15(S-HETE (15-hydroxy-eicosatetraenoic acid; 0 vs. 120pM; p = 0.0014, AA (1.5-fold; p = 0.0055 and docosahexaenoic acid (DHA, C22∶6; 2-fold; p = 0.0033 were higher in MUHO. This emphasizes a direct contribution of adipocytes to local adipose tissue inflammation. Elevated DHA, as an inhibitor of prostaglandin synthesis, might be a hint for counter-regulatory mechanisms in MUHO.We identified adipocyte-inherent metabolic alterations discriminating between MHO and MUHO.

  20. Hydrophilic Interaction Liquid Chromatography/Mass Spectrometry: An Attractive and Prospective Method for the Quantitative Bioanalysis in Drug Metabolism.

    Science.gov (United States)

    Li, Zheng; Han, Jie; Sun, Shi-an; Chen, Kai; Tang, Dao-quan

    2016-01-01

    During the development, dosage optimization and safety evaluation of a drug, rapid and precise monitoring of administered drug and/or its metabolites in biological samples including blood, plasma, serum, tissues and saliva are vital. As drug biotransformation produces more hydrophilic metabolites for the enhancement of drug elimination, which is often a challenge for traditional reversed-phase liquid chromatography (RPLC) separation. Because hydrophilic interaction liquid chromatography (HILIC) is capable of retaining polar compounds and readily compatible with mass spectrometry (MS), HILIC has been used as a complementary separation technique to RPLC for analysis of polar metabolites, especially polar drugs and their metabolites. This review covers core aspects of HILIC-MS/MS method and overall profile of its application in analysis of drug and/or its metabolites. The emphasis of this paper has been placed on the applications of HILIC-MS/MS method in quantitative bioanalysis of drugs alone or along with their metabolites in drug metabolism studies in recent years. As a fundamental and critical step of bioanalytical method, conventional sample preparation techniques of biological matrices for the HILIC-MS/MS analysis of drugs and/or their metabolites are also briefly featured.

  1. Proline and hydroxyproline metabolism: implications for animal and human nutrition

    OpenAIRE

    Wu, Guoyao; Bazer, Fuller W.; Burghardt, Robert C.; Johnson, Gregory A.; Kim, Sung Woo; Knabe, Darrell A.; Li, Peng; Li, Xilong; McKnight, Jason R.; Satterfield, M. Carey; Spencer, Thomas E.

    2010-01-01

    Proline plays important roles in protein synthesis and structure, metabolism (particularly the synthesis of arginine, polyamines, and glutamate via pyrroline-5-carboxylate), and nutrition, as well as wound healing, antioxidative reactions, and immune responses. On a pergram basis, proline plus hydroxyproline are most abundant in collagen and milk proteins, and requirements of proline for whole-body protein synthesis are the greatest among all amino acids. Therefore, physiological needs for pr...

  2. Understanding the determinants of selectivity in drug metabolism through modeling of dextromethorphan oxidation by cytochrome P450

    Science.gov (United States)

    Oláh, Julianna; Mulholland, Adrian J.; Harvey, Jeremy N.

    2011-01-01

    Cytochrome P450 enzymes play key roles in the metabolism of the majority of drugs. Improved models for prediction of likely metabolites will contribute to drug development. In this work, two possible metabolic routes (aromatic carbon oxidation and O-demethylation) of dextromethorphan are compared using molecular dynamics (MD) simulations and density functional theory (DFT). The DFT results on a small active site model suggest that both reactions might occur competitively. Docking and MD studies of dextromethorphan in the active site of P450 2D6 show that the dextromethorphan is located close to heme oxygen in a geometry apparently consistent with competitive metabolism. In contrast, calculations of the reaction path in a large protein model [using a hybrid quantum mechanical–molecular mechanics (QM/MM) method] show a very strong preference for O-demethylation, in accordance with experimental results. The aromatic carbon oxidation reaction is predicted to have a high activation energy, due to the active site preventing formation of a favorable transition-state structure. Hence, the QM/MM calculations demonstrate a crucial role of many active site residues in determining reactivity of dextromethorphan in P450 2D6. Beyond substrate binding orientation and reactivity of Compound I, successful metabolite predictions must take into account the detailed mechanism of oxidation in the protein. These results demonstrate the potential of QM/MM methods to investigate specificity in drug metabolism. PMID:21444768

  3. Probiotic modulation of symbiotic gut microbial-host metabolic interactions in a humanized microbiome mouse model

    NARCIS (Netherlands)

    Martin, F.P.J.; Wang, Y.; Sprenger, N.; Yap, K.S.; Rezzi, S.; Ramadan, Z.; Peré-Trepat, E.; Rochat, F.; Cherbut, C.; Bladeren, van P.J.; Fay, L.B.; Kochhar, S.; LindOn, J.C.; Holmes, E.; Nicholson, J.K.

    2008-01-01

    The transgenomic metabolic effects of exposure to either Lactobacillus paracasei or Lactobacillus rhamnosus probiotics have been measured and mapped in humanized extended genome mice (germ-free mice colonized with human baby flora). Statistical analysis of the compartmental fluctuations in diverse

  4. CYP2C9 Genotype vs. Metabolic Phenotype for Individual Drug Dosing—A Correlation Analysis Using Flurbiprofen as Probe Drug

    Science.gov (United States)

    Vogl, Silvia; Lutz, Roman W.; Schönfelder, Gilbert; Lutz, Werner K.

    2015-01-01

    Currently, genotyping of patients for polymorphic enzymes responsible for metabolic elimination is considered a possibility to adjust drug dose levels. For a patient to profit from this procedure, the interindividual differences in drug metabolism within one genotype should be smaller than those between different genotypes. We studied a large cohort of healthy young adults (283 subjects), correlating their CYP2C9 genotype to a simple phenotyping metric, using flurbiprofen as probe drug. Genotyping was conducted for CYP2C9*1, *2, *3. The urinary metabolic ratio MR (concentration of CYP2C9-dependent metabolite divided by concentration of flurbiprofen) determined two hours after flurbiprofen (8.75 mg) administration served as phenotyping metric. Linear statistical models correlating genotype and phenotype provided highly significant allele-specific MR estimates of 0.596 for the wild type allele CYP2C9*1, 0.405 for CYP2C9*2 (68 % of wild type), and 0.113 for CYP2C9*3 (19 % of wild type). If these estimates were used for flurbiprofen dose adjustment, taking 100 % for genotype *1/*1, an average reduction to 84 %, 60 %, 68 %, 43 %, and 19 % would result for genotype *1/*2, *1/*3, *2/*2, *2/*3, and *3/*3, respectively. Due to the large individual variation within genotypes with coefficients of variation ≥ 20 % and supposing the normal distribution, one in three individuals would be out of the average optimum dose by more than 20 %, one in 20 would be 40 % off. Whether this problem also applies to other CYPs and other drugs has to be investigated case by case. Our data for the given example, however, puts the benefit of individual drug dosing to question, if it is exclusively based on genotype. PMID:25775139

  5. CYP2C9 genotype vs. metabolic phenotype for individual drug dosing--a correlation analysis using flurbiprofen as probe drug.

    Science.gov (United States)

    Vogl, Silvia; Lutz, Roman W; Schönfelder, Gilbert; Lutz, Werner K

    2015-01-01

    Currently, genotyping of patients for polymorphic enzymes responsible for metabolic elimination is considered a possibility to adjust drug dose levels. For a patient to profit from this procedure, the interindividual differences in drug metabolism within one genotype should be smaller than those between different genotypes. We studied a large cohort of healthy young adults (283 subjects), correlating their CYP2C9 genotype to a simple phenotyping metric, using flurbiprofen as probe drug. Genotyping was conducted for CYP2C9*1, *2, *3. The urinary metabolic ratio MR (concentration of CYP2C9-dependent metabolite divided by concentration of flurbiprofen) determined two hours after flurbiprofen (8.75 mg) administration served as phenotyping metric. Linear statistical models correlating genotype and phenotype provided highly significant allele-specific MR estimates of 0.596 for the wild type allele CYP2C9*1, 0.405 for CYP2C9*2 (68 % of wild type), and 0.113 for CYP2C9*3 (19 % of wild type). If these estimates were used for flurbiprofen dose adjustment, taking 100 % for genotype *1/*1, an average reduction to 84 %, 60 %, 68 %, 43 %, and 19 % would result for genotype *1/*2, *1/*3, *2/*2, *2/*3, and *3/*3, respectively. Due to the large individual variation within genotypes with coefficients of variation ≥ 20 % and supposing the normal distribution, one in three individuals would be out of the average optimum dose by more than 20 %, one in 20 would be 40 % off. Whether this problem also applies to other CYPs and other drugs has to be investigated case by case. Our data for the given example, however, puts the benefit of individual drug dosing to question, if it is exclusively based on genotype.

  6. CYP2C9 genotype vs. metabolic phenotype for individual drug dosing--a correlation analysis using flurbiprofen as probe drug.

    Directory of Open Access Journals (Sweden)

    Silvia Vogl

    Full Text Available Currently, genotyping of patients for polymorphic enzymes responsible for metabolic elimination is considered a possibility to adjust drug dose levels. For a patient to profit from this procedure, the interindividual differences in drug metabolism within one genotype should be smaller than those between different genotypes. We studied a large cohort of healthy young adults (283 subjects, correlating their CYP2C9 genotype to a simple phenotyping metric, using flurbiprofen as probe drug. Genotyping was conducted for CYP2C9*1, *2, *3. The urinary metabolic ratio MR (concentration of CYP2C9-dependent metabolite divided by concentration of flurbiprofen determined two hours after flurbiprofen (8.75 mg administration served as phenotyping metric. Linear statistical models correlating genotype and phenotype provided highly significant allele-specific MR estimates of 0.596 for the wild type allele CYP2C9*1, 0.405 for CYP2C9*2 (68 % of wild type, and 0.113 for CYP2C9*3 (19 % of wild type. If these estimates were used for flurbiprofen dose adjustment, taking 100 % for genotype *1/*1, an average reduction to 84 %, 60 %, 68 %, 43 %, and 19 % would result for genotype *1/*2, *1/*3, *2/*2, *2/*3, and *3/*3, respectively. Due to the large individual variation within genotypes with coefficients of variation ≥ 20 % and supposing the normal distribution, one in three individuals would be out of the average optimum dose by more than 20 %, one in 20 would be 40 % off. Whether this problem also applies to other CYPs and other drugs has to be investigated case by case. Our data for the given example, however, puts the benefit of individual drug dosing to question, if it is exclusively based on genotype.

  7. Efficacy of dietary supplementation with botanicals on carbohydrate metabolism in humans.

    Science.gov (United States)

    Cefalu, William T; Ye, Jianping; Wang, Zhong Q

    2008-06-01

    Botanical products are widely used in nutritional supplementation for promotion of health or prevention of diseases. With the high prevalence of obesity and type 2 diabetes, abnormalities in carbohydrate metabolism are common in the general population and obtaining glycemic control is important in reducing the complications of diabetes. If shown to be effective, botanical products have a unique position in potentially aiding the general public in regard to obesity and diabetes. They can be obtained "over-the-counter" and may have less side effects compared to many synthetic drugs. Although most of the popular botanicals have a long history in folk medicine, there is paucity of data regarding their efficacy and safety, particularly as it relates to human studies. In this review, we discuss the data that was available in the literature for nine botanicals that are frequently promoted to help manage blood glucose. They are Bitter Melon (Momordica charantia), Fenugreek (trigonella foenum graecum), Gymnema Sylvestre, Ivy Gourd (Coccinia indica), Nopal or Prickly Pear Cactus (Opuntia streptacantha), Ginseng, Aloe Vera, Russian Tarragon (Artemisia dracunculus), and Garlic (Allium sativum). The discussion is emphasized on the clinical aspect of these botanicals. Due to the lack of sufficient evidence from clinical studies for any of the botanicals reviewed, it is premature to actively recommend use of any particular herb to treat either glucose or other risk factors. Thus, well defined randomized clinical trials are warranted in this area.

  8. Modulation of lipoprotein metabolism by antisense technology: preclinical drug discovery methodology.

    Science.gov (United States)

    Crooke, Rosanne M; Graham, Mark J

    2013-01-01

    Antisense oligonucleotides (ASOs) are a new class of specific therapeutic agents that alter the intermediary metabolism of mRNA, resulting in the suppression of disease-associated gene products. ASOs exert their pharmacological effects after hybridizing, via Watson-Crick base pairing, to a specific target RNA. If appropriately designed, this event results in the recruitment of RNase H, the degradation of targeted mRNA or pre-mRNA, and subsequent inhibition of the synthesis of a specific protein. A key advantage of the technology is the ability to selectively inhibit targets that cannot be modulated by traditional therapeutics such as structural proteins, transcription factors, and, of topical interest, lipoproteins. In this chapter, we will first provide an overview of antisense technology, then more specifically describe the status of lipoprotein-related genes that have been studied using the antisense platform, and finally, outline the general methodology required to design and evaluate the in vitro and in vivo efficacy of those drugs.

  9. Tiamulin selectively inhibits oxidative hepatic steroid and drug metabolism in vitro in the pig.

    Science.gov (United States)

    Witkamp, R F; Nijmeijer, S M; Csikó, G; van Miert, A S

    1994-08-01

    The simultaneous use of the antibiotic tiamulin with certain ionophoric antibiotics (monensin, salinomycin) may give rise to a toxic interaction in pigs and poultry. In the present study, effects of tiamulin on hepatic cytochrome P450 activities in vitro were studied using pig liver microsomes. When tiamulin was added to the incubation medium the N-demethylation rate of ethylmorphine and the hydroxylation of testosterone at the 6 beta- and 11 alpha-positions was strongly inhibited. Tiamulin inhibited these activities more than SKF525A or cimetidine, but less than ketoconazole. The microsomal N-demethylation rate of erythromycin and the hydroxylation of testosterone at the 2 beta-position were inhibited to a lesser degree, whereas the ethoxyresorufin-O-deethylation, aniline hydroxylation and testosterone hydroxylations at the 15 alpha- and 15 beta-positions were not affected by tiamulin. No in vitro complexation by tiamulin of cytochrome P450 resulting in a loss of CO-binding capacity could be demonstrated. Results from the present study suggest a selective inhibition of cytochrome P450 enzymes in pigs, probably belonging to the P4503A subfamily. The mechanism of this interaction is still unclear. However, interactions between tiamulin and those veterinary drugs or endogenous compounds which undergo oxidative metabolism by P450 enzymes must be considered. More research is needed to reveal which of the P450 enzymes are affected by tiamulin in order to improve the understanding and probably the predictability of this interaction.

  10. Metabolic syndrome and drug discontinuation in schizophrenia: a randomized trial comparing aripiprazole olanzapine and haloperidol.

    Science.gov (United States)

    Parabiaghi, A; Tettamanti, M; D'Avanzo, B; Barbato, A

    2016-01-01

    To determine whether the prescription of aripiprazole, compared with olanzapine and haloperidol, was associated with a lower frequency of metabolic syndrome (MS) and treatment discontinuation at 1 year. Patients were randomly assigned to be treated open-label and according to usual clinical practice with either aripiprazole, olanzapine, or haloperidol and followed up for 1 year. Three hundred out-patients with persistent schizophrenia were recruited in 35 mental health services. The intention-to-treat (ITT) analysis found no significant differences in the rate of MS between aripiprazole (37%), olanzapine (47%), and haloperidol (42%). Treatment discontinuation for any cause was higher for aripiprazole (52%) than for olanzapine (33%; OR, 0.41; P = 0.004), or haloperidol (37%; OR, 0.51; P = 0.030). No significant difference was found between olanzapine and haloperidol. Time to discontinuation for any cause was longer for olanzapine than for aripiprazole (HR, 0.55; P haloperidol and aripiprazole, or between olanzapine and haloperidol. The prescription of aripiprazole did not significantly reduce the rates of MS, but its treatment retention was worse. Aripiprazole cannot be considered the safest and most effective drug for maintenance treatment of schizophrenia in routine care, although it may have a place in antipsychotic therapy. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Monoglyceride lipase as a drug target: At the crossroads of arachidonic acid metabolism and endocannabinoid signaling.

    Science.gov (United States)

    Grabner, Gernot F; Zimmermann, Robert; Schicho, Rudolf; Taschler, Ulrike

    2017-07-01

    Monoglyerides (MGs) are short-lived, intermediary lipids deriving from the degradation of phospho- and neutral lipids, and monoglyceride lipase (MGL), also designated as monoacylglycerol lipase (MAGL), is the major enzyme catalyzing the hydrolysis of MGs into glycerol and fatty acids. This distinct function enables MGL to regulate a number of physiological and pathophysiological processes since both MGs and fatty acids can act as signaling lipids or precursors thereof. The most prominent MG species acting as signaling lipid is 2-arachidonoyl glycerol (2-AG) which is the most abundant endogenous agonist of cannabinoid receptors in the body. Importantly, recent observations demonstrate that 2-AG represents a quantitatively important source for arachidonic acid, the precursor of prostaglandins and other inflammatory mediators. Accordingly, MGL-mediated 2-AG degradation affects lipid signaling by cannabinoid receptor-dependent and independent mechanisms. Recent genetic and pharmacological studies gave important insights into MGL's role in (patho-)physiological processes, and the enzyme is now considered as a promising drug target for a number of disorders including cancer, neurodegenerative and inflammatory diseases. This review summarizes the basics of MG (2-AG) metabolism and provides an overview on the therapeutic potential of MGL. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. The Efficacy of Dandelion Root Extract in Inducing Apoptosis in Drug-Resistant Human Melanoma Cells

    Directory of Open Access Journals (Sweden)

    S. J. Chatterjee

    2011-01-01

    Full Text Available Notoriously chemoresistant melanoma has become the most prevalent form of cancer for the 25–29 North American age demographic. Standard treatment after early detection involves surgical excision (recurrence is possible, and metastatic melanoma is refractory to immuno-, radio-, and most harmful chemotherapies. Various natural compounds have shown efficacy in killing different cancers, albeit not always specifically. In this study, we show that dandelion root extract (DRE specifically and effectively induces apoptosis in human melanoma cells without inducing toxicity in noncancerous cells. Characteristic apoptotic morphology of nuclear condensation and phosphatidylserine flipping to the outer leaflet of the plasma membrane of A375 human melanoma cells was observed within 48 hours. DRE-induced apoptosis activates caspase-8 in A375 cells early on, demonstrating employment of an extrinsic apoptotic pathway to kill A375 cells. Reactive Oxygen Species (ROS generated from DRE-treated isolated mitochondria indicates that natural compounds in DRE can also directly target mitochondria. Interestingly, the relatively resistant G361 human melanoma cell line responded to DRE when combined with the metabolism interfering antitype II diabetic drug metformin. Therefore, treatment with this common, yet potent extract of natural compounds has proven novel in specifically inducing apoptosis in chemoresistant melanoma, without toxicity to healthy cells.

  13. Metabolic Disorder in Chronic Obstructive Pulmonary Disease (COPD) Patients: Towards a Personalized Approach Using Marine Drug Derivatives.

    Science.gov (United States)

    Lamonaca, Palma; Prinzi, Giulia; Kisialiou, Aliaksei; Cardaci, Vittorio; Fini, Massimo; Russo, Patrizia

    2017-03-20

    Metabolic disorder has been frequently observed in chronic obstructive pulmonary disease (COPD) patients. However, the exact correlation between obesity, which is a complex metabolic disorder, and COPD remains controversial. The current study summarizes a variety of drugs from marine sources that have anti-obesity effects and proposed potential mechanisms by which lung function can be modulated with the anti-obesity activity. Considering the similar mechanism, such as inflammation, shared between obesity and COPD, the study suggests that marine derivatives that act on the adipose tissues to reduce inflammation may provide beneficial therapeutic effects in COPD subjects with high body mass index (BMI).

  14. Transformation and sorption of illicit drug biomarkers in sewer systems: understanding the role of suspended solids in raw wastewater

    DEFF Research Database (Denmark)

    Ramin, Pedram; Brock, Andreas Libonati; Polesel, Fabio

    2016-01-01

    substrates (primary metabolic processes) and transformation of illicit drug biomarkers (secondary metabolic processes) by suspended biomass. Sixteen drug biomarkers were targeted, including mephedrone, methadone, cocaine, heroin, codeine and tetrahydrocannabinol (THC) and their major human metabolites. Batch...

  15. Regulation of drug metabolism and toxicity by multiple factors of genetics, epigenetics, lncRNAs, gut microbiota, and diseases: a meeting report of the 21st International Symposium on Microsomes and Drug Oxidations (MDO

    Directory of Open Access Journals (Sweden)

    Ai-Ming Yu

    2017-03-01

    Full Text Available Variations in drug metabolism may alter drug efficacy and cause toxicity; better understanding of the mechanisms and risks shall help to practice precision medicine. At the 21st International Symposium on Microsomes and Drug Oxidations held in Davis, California, USA, in October 2–6, 2016, a number of speakers reported some new findings and ongoing studies on the regulation mechanisms behind variable drug metabolism and toxicity, and discussed potential implications to personalized medications. A considerably insightful overview was provided on genetic and epigenetic regulation of gene expression involved in drug absorption, distribution, metabolism, and excretion (ADME and drug response. Altered drug metabolism and disposition as well as molecular mechanisms among diseased and special populations were presented. In addition, the roles of gut microbiota in drug metabolism and toxicology as well as long non-coding RNAs in liver functions and diseases were discussed. These findings may offer new insights into improved understanding of ADME regulatory mechanisms and advance drug metabolism research.

  16. Generation of human pluripotent stem cell-derived hepatocyte-like cells for drug toxicity screening.

    Science.gov (United States)

    Takayama, Kazuo; Mizuguchi, Hiroyuki

    2017-02-01

    Because drug-induced liver injury is one of the main reasons for drug development failures, it is important to perform drug toxicity screening in the early phase of pharmaceutical development. Currently, primary human hepatocytes are most widely used for the prediction of drug-induced liver injury. However, the sources of primary human hepatocytes are limited, making it difficult to supply the abundant quantities required for large-scale drug toxicity screening. Therefore, there is an urgent need for a novel unlimited, efficient, inexpensive, and predictive model which can be applied for large-scale drug toxicity screening. Human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are able to replicate indefinitely and differentiate into most of the body's cell types, including hepatocytes. It is expected that hepatocyte-like cells generated from human ES/iPS cells (human ES/iPS-HLCs) will be a useful tool for drug toxicity screening. To apply human ES/iPS-HLCs to various applications including drug toxicity screening, homogenous and functional HLCs must be differentiated from human ES/iPS cells. In this review, we will introduce the current status of hepatocyte differentiation technology from human ES/iPS cells and a novel method to predict drug-induced liver injury using human ES/iPS-HLCs. Copyright © 2016 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  17. Ablation of Steroid Receptor Coactivator-3 resembles the human CACT metabolic myopathy

    OpenAIRE

    York, Brian; Reineke, Erin L.; Sagen, Jørn V.; Nikolai, Bryan C.; Zhou, Suoling; Louet, Jean-Francois; Chopra, Atul R.; Chen, Xian; Reed, Graham; Noebels, Jeffrey; Adesina, Adekunle M.; Yu, Hui; Wong, Lee-Jun C.; Tsimelzon, Anna; Hilsenbeck, Susan

    2012-01-01

    Oxidation of lipid substrates is essential for survival in fasting and other catabolic conditions, sparing glucose for the brain and other glucose-dependent tissues. Here we show Steroid Receptor Coactivator-3 (SRC-3) plays a central role in long chain fatty acid metabolism by directly regulating carnitine/acyl-carnitine translocase (CACT) gene expression. Genetic deficiency of CACT in humans is accompanied by a constellation of metabolic and toxicity phenotypes including hypoketonemia, hypog...

  18. Inhibition of Sphingolipid Metabolism Enhances Resveratrol Chemotherapy in Human Gastric Cancer Cells

    OpenAIRE

    Shin, Kyong-Oh; Park, Nam-Young; Seo, Cho-Hee; Hong, Seon-Pyo; Oh, Ki-Wan; Hong, Jin-Tae; Han, Sang-Kil; Lee, Yong-Moon

    2012-01-01

    Resveratrol, a chemopreventive agent, is rapidly metabolized in the intestine and liver via glucuronidation. Thus, the pharmacokinetics of resveratrol limits its efficacy. To improve efficacy, the activity of resveratrol was investigated in the context of sphingolipid metabolism in human gastric cancer cells. Diverse sphingolipid metabolites, including dihydroceramides (DHCer), were tested for their ability to induce resveratrol cytotoxicity. Exposure to resveratrol (100 ?M) for 24 hr induced...

  19. Metabolic profiling detects early effects of environmental and lifestyle exposure to cadmium in a human population

    OpenAIRE

    Ellis, James K; Athersuch, Toby J; Thomas, Laura DK; Teichert, Friederike; Pérez-Trujillo, Miriam; Svendsen, Claus; Spurgeon, David J; Singh, Rajinder; Järup, Lars; Bundy, Jacob G; Keun, Hector C

    2012-01-01

    Background: The ‘exposome’ represents the accumulation of all environmental exposures across a lifetime. Topdown strategies are required to assess something this comprehensive, and could transform our understanding of how environmental factors affect human health. Metabolic profiling (metabonomics/metabolomics) defines an individual’s metabolic phenotype, which is influenced by genotype, diet, lifestyle, health and xenobiotic exposure, and could also reveal intermediate biomarkers...

  20. Identifying anti-growth factors for human cancer cell lines through genome-scale metabolic modeling

    DEFF Research Database (Denmark)

    Ghaffari, Pouyan; Mardinoglu, Adil; Asplund, Anna

    2015-01-01

    Human cancer cell lines are used as important model systems to study molecular mechanisms associated with tumor growth, hereunder how genomic and biological heterogeneity found in primary tumors affect cellular phenotypes. We reconstructed Genome scale metabolic models (GEMs) for eleven cell lines...... based on RNA-Seq data and validated the functionality of these models with data from metabolite profiling. We used cell line-specific GEMs to analyze the differences in the metabolism of cancer cell lines, and to explore the heterogeneous expression of the metabolic subsystems. Furthermore, we predicted...... for inhibition of cell growth may provide leads for the development of efficient cancer treatment strategies....

  1. Evolutionary Medicine: The Ongoing Evolution of Human Physiology and Metabolism.

    Science.gov (United States)

    Rühli, Frank; van Schaik, Katherine; Henneberg, Maciej

    2016-11-01

    The field of evolutionary medicine uses evolutionary principles to understand changes in human anatomy and physiology that have occurred over time in response to environmental changes. Through this evolutionary-based approach, we can understand disease as a consequence of anatomical and physiological "trade-offs" that develop to facilitate survival and reproduction. We demonstrate how diachronic study of human anatomy and physiology is fundamental for an increased understanding of human health and disease. ©2016 Int. Union Physiol. Sci./Am. Physiol. Soc.

  2. Human volunteer studies with non-pharmaceutical chemicals: metabolism and pharmacokinetic studies.

    Science.gov (United States)

    Wilks, M F; Woollen, B H

    1994-06-01

    1. Human volunteer studies are an essential part of drug development but their use in the area of non-pharmaceutical chemicals has so far been very limited. Such studies can have considerable value in the assessment and improvement of the safe use of chemicals. 2. Once metabolic pathways and target metabolites have been identified in volunteers this information can be used in studies in the workplace or in the general population. Studies should be performed selectively only if there is both a toxic hazard and a significant exposure potential. In addition, they should only be carried out if the required information cannot be obtained in any other way. 3. Volunteer studies with non-pharmaceuticals have become increasingly acceptable in the light of established international guidelines, no-fault compensation, improvements in study design and technical developments which allow the use of very low dose levels. The final decision on whether to carry out a study must always rest with an independent ethical committee. 4. The practical aspects of the study should be specified in a detailed protocol conforming with the principles of good clinical practice. The safety of volunteers must be of paramount concern throughout. Depending on the nature of the chemical and the study, it may be advisable to carry out studies in a clinical facility where equipment is available for the treatment of any emergencies that might occur. 5. Numerous investigators have now shown that human volunteer studies are ethically acceptable, practicable and yield important information. The risk to volunteers is minimal and this approach can lead to an improved foundation for occupational hygiene standards, more accurate risk assessment and thus better protection of the workforce and the general population.

  3. The NQO1 bioactivatable drug, β-lapachone, alters the redox state of NQO1+ pancreatic cancer cells, causing perturbation in central carbon metabolism.

    Science.gov (United States)

    Silvers, Molly A; Deja, Stanislaw; Singh, Naveen; Egnatchik, Robert A; Sudderth, Jessica; Luo, Xiuquan; Beg, Muhammad S; Burgess, Shawn C; DeBerardinis, Ralph J; Boothman, David A; Merritt, Matthew E

    2017-11-03

    Many cancer treatments, such as those for managing recalcitrant tumors like pancreatic ductal adenocarcinoma, cause off-target toxicities in normal, healthy tissue, highlighting the need for more tumor-selective chemotherapies. β-Lapachone is bioactivated by NAD(P)H:quinone oxidoreductase 1 (NQO1). This enzyme exhibits elevated expression in most solid cancers and therefore is a potential cancer-specific target. β-Lapachone's therapeutic efficacy partially stems from the drug's induction of a futile NQO1-mediated redox cycle that causes high levels of superoxide and then peroxide formation, which damages DNA and causes hyperactivation of poly(ADP-ribose) polymerase, resulting in extensive NAD + /ATP depletion. However, the effects of this drug on energy metabolism due to NAD + depletion were never described. The futile redox cycle rapidly consumes O 2 , rendering standard assays of Krebs cycle turnover unusable. In this study, a multimodal analysis, including metabolic imaging using hyperpolarized pyruvate, points to reduced oxidative flux due to NAD + depletion after β-lapachone treatment of NQO1+ human pancreatic cancer cells. NAD + -sensitive pathways, such as glycolysis, flux through lactate dehydrogenase, and the citric acid cycle (as inferred by flux through pyruvate dehydrogenase), were down-regulated by β-lapachone treatment. Changes in flux through these pathways should generate biomarkers useful for in vivo dose responses of β-lapachone treatment in humans, avoiding toxic side effects. Targeting the enzymes in these pathways for therapeutic treatment may have the potential to synergize with β-lapachone treatment, creating unique NQO1-selective combinatorial therapies for specific cancers. These findings warrant future studies of intermediary metabolism in patients treated with β-lapachone. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Characterization of the human cytochrome P450 enzymes involved in the metabolism of dihydrocodeine

    Science.gov (United States)

    Kirkwood, L. C.; Nation, R. L.; Somogyi, A. A.

    1997-01-01

    Aims Using human liver microsomes from donors of the CYP2D6 poor and extensive metabolizer genotypes, the role of individual cytochromes P-450 in the oxidative metabolism of dihydrocodeine was investigated. Methods The kinetics of formation of N- and O-demethylated metabolites, nordihydrocodeine and dihydromorphine, were determined using microsomes from six extensive and one poor metabolizer and the effects of chemical inhibitors selective for individual P-450 enzymes of the 1A, 2A, 2C, 2D, 2E and 3A families and of LKM1 (anti-CYP2D6) antibodies were studied. Results Nordihydrocodeine was the major metabolite in both poor and extensive metabolizers. Kinetic constants for N-demethylation derived from the single enzyme Michaelis-Menten model did not differ between the two groups. Troleandomycin and erythromycin selectively inhibited N-demethylation in both extensive and poor metabolizers. The CYP3A inducer, α-naphthoflavone, increased N-demethylation rates. The kinetics of formation of dihydromorphine in both groups were best described by a single enzyme Michaelis-Menten model although inhibition studies in extensive metabolizers suggested involvement of two enzymes with similar Km values. The kinetic constants for O-demethylation were significantly different in extensive and poor metabolizers. The extensive metabolizers had a mean intrinsic clearance to dihydromorphine more than ten times greater than the poor metabolizer. The CYP2D6 chemical inhibitors, quinidine and quinine, and LKM1 antibodies inhibited O-demethylation in extensive metabolizers; no effect was observed in microsomes from a poor metabolizer. Conclusions CYP2D6 is the major enzyme mediating O-demethylation of dihydrocodeine to dihydromorphine. In contrast, nordihydrocodeine formation is predominantly catalysed by CYP3A. PMID:9431830

  5. The effect of trimethoprim on CYP2C8 mediated rosiglitazone metabolism in human liver microsomes and healthy subjects

    Science.gov (United States)

    Hruska, M W; Amico, J A; Langaee, T Y; Ferrell, R E; Fitzgerald, S M; Frye, R F

    2005-01-01

    Aims Rosiglitazone, a thiazolidinedione antidiabetic medication used in the treatment of Type 2 diabetes mellitus, is predominantly metabolized by the cytochrome P450 (CYP) enzyme CYP2C8. The anti-infective drug trimethoprim has been shown in vitro to be a selective inhibitor of CYP2C8. The purpose of this study was to evaluate the effect of trimethoprim on the CYP2C8 mediated metabolism of rosiglitazone in vivo and in vitro. Methods The effect of trimethoprim on the metabolism of rosiglitazone in vitro was assessed in pooled human liver microsomes. The effect in vivo was determined by evaluating rosiglitazone pharmacokinetics in the presence and absence of trimethoprim. Eight healthy subjects (four men and four women) completed a randomized, cross-over study. Subjects received single dose rosiglitazone (8 mg) in the presence and absence of trimethoprim 200 mg given twice daily for 5 days. Results Trimethoprim inhibited rosiglitazone metabolism both in vitro and in vivo. Inhibition of rosiglitazone para-hydroxylation by trimethoprim in vitro was found to be competitive with apparent Ki and IC50 values of 29 µm and 54.5 µm, respectively. In the presence of trimethoprim, rosiglitazone plasma AUC was increased by 31% (P = 0.01) from 2774 ± 645 µg l−1 h to 3643 ± 1051 µg l−1 h (95% confidence interval (Cl) for difference 189, 1549), and half-life was increased by 27% (P = 0.006) from 3.3 ± 0.5 to 4.2 ± 0.8 h (95% Cl for difference 0.36, 1.5). Trimethoprim reduced the para-O-sulphate rosiglitazone/rosiglitazone and the N-desmethylrosiglitazone/rosiglitazone AUC(0–24) ratios by 22% and 38%, respectively. Conclusions These results indicate that trimethoprim is a competitive inhibitor of CYP2C8-mediated rosiglitazone metabolism in vitro and that trimethoprim administration increases plasma rosiglitazone concentrations in healthy subjects. PMID:15606443

  6. Importância do metabolismo no planejamento de fármacos The importance of metabolism in drug design

    Directory of Open Access Journals (Sweden)

    Dárcio Gomes Pereira

    2007-02-01

    Full Text Available It is widely recognized that pharmacokinetic optimization needs to be addressed early in drug discovery to reduce the high failure rate in bringing drugs to market. Poor absorption, too short duration of action due to high elimination rate, or the presence of active metabolites are examples of properties that can potentially lead to unsuccessful clinical programmes. Here I describe a brief overview of advantages and molecular strategies for improving metabolic and pharmacokinetic properties applied to the discovery of fluconazol, beta-blockers, ritonavir and ezetimibe and to the development of the prodrugs enalapril and bambuterol.

  7. Kinetics of adenylate metabolism in human and rat myocardium

    OpenAIRE

    Tavenier, M.; Skladanowski, A.C.; Abreu, R.A. de; Jong, J.W. de

    1995-01-01

    textabstractPathways producing and converting adenosine have hardly been investigated in human heart, contrasting work in other species. We compared the kinetics of enzymes associated with purine degradation and salvage in human and rat heart cytoplasm assaying for adenosine deaminase, nucleoside phosphorylase, xanthine oxidoreductase, AMP deaminase, AMP- and IMP-specific 5′-nucleotidases, adenosine kinase and hypoxanthine guanine phosphoribosyltransferase (HGPRT). Xanthine oxidoreductase was...

  8. Comparison of cerebral metabolism of glucose in normal human and cancer patients

    International Nuclear Information System (INIS)

    Si, M.

    2007-01-01

    Full text: Objective: To determine whether the cerebral metabolism in various regions of the normal human brain differs from those of cancer patients in aging by using 18F-FDG PET instrument and SPM software. Materials and Methods We reviewed clinical information of 295 healthy normal samples so called 'normal group' (ranging 21 to 88; mean age+/-SD: 50+/-14) and 290 cancer patients called 'cancer group' (ranging 21 to 85; mean age+/-SD: 54+/-14) who were examined by a whole body GE Discovery LS PET-CT instrument in our center from Aug. 2004 to Dec. 2005.They were selected with: (i) absence of clear focal brain lesions (epilepsy, cerebrovascular diseases etc.); (ii) absence of metabolic diseases, such as hyperthyroidism, hypothyroidism and diabetes; (iii) absence of psychiatric disorders and abuse of drugs and alcohol;( iiii) cancer patients were diagnosed definitely of variable cancers except brain cancer or brain metastasis. Both groups were sub grouped into six with the interval of 10 years old starting from 21, and the gender, educational background and serum glucose are matched. All 12 subgroups were compared to the subgroup of normal 31-40 years old called 'control subgroup' (84 samples; mean age+/-SD: 37.15+/- 2.63). All samples were injected with 18F-FDG (5.55MBq/kg), 45-60 minutes later; their brains were scanned for 10 minutes. Pixel-by-pixel t-statistic analysis was applied to all brain images using the Statistical parametric mapping (SPM2). The hypometabolic areas (p < 0. 01 or p<0.001, uncorrected) were identified in the Stereotaxic coordinate human brain atlas and three dimensional localized by MNI Space utility (MSU) software. Results:1.With increasing of age interval, similar hypometabolic brain areas are detected in both 'normal group' and 'cancer group', they are mainly in the cortical structures such as bilateral prefrontal cortex (BA9), superior temporal gyrus (BA22), parietal cortex (inferior parietal lobule and precuneus(BA40), insula (BA13

  9. Recombinant yeast screen for new inhibitors of human acetyl-CoA carboxylase 2 identifies potential drugs to treat obesity

    Science.gov (United States)

    Marjanovic, Jasmina; Chalupska, Dominika; Patenode, Caroline; Coster, Adam; Arnold, Evan; Ye, Alice; Anesi, George; Lu, Ying; Okun, Ilya; Tkachenko, Sergey; Haselkorn, Robert; Gornicki, Piotr

    2010-01-01

    Acetyl-CoA carboxylase (ACC) is a key enzyme of fatty acid metabolism with multiple isozymes often expressed in different eukaryotic cellular compartments. ACC-made malonyl-CoA serves as a precursor for fatty acids; it also regulates fatty acid oxidation and feeding behavior in animals. ACC provides an important target for new drugs to treat human diseases. We have developed an inexpensive nonradioactive high-throughput screening system to identify new ACC inhibitors. The screen uses yeast gene-replacement strains depending for growth on cloned human ACC1 and ACC2. In “proof of concept” experiments, growth of such strains was inhibited by compounds known to target human ACCs. The screen is sensitive and robust. Medium-size chemical libraries yielded new specific inhibitors of human ACC2. The target of the best of these inhibitors was confirmed with in vitro enzymatic assays. This compound is a new drug chemotype inhibiting human ACC2 with 2.8 μM IC50 and having no effect on human ACC1 at 100 μM. PMID:20439761

  10. Metabolically stable bradykinin B2 receptor agonists enhance transvascular drug delivery into malignant brain tumors by increasing drug half-life

    Directory of Open Access Journals (Sweden)

    Glen Daniel

    2009-05-01

    Full Text Available Abstract Background The intravenous co-infusion of labradimil, a metabolically stable bradykinin B2 receptor agonist, has been shown to temporarily enhance the transvascular delivery of small chemotherapy drugs, such as carboplatin, across the blood-brain tumor barrier. It has been thought that the primary mechanism by which labradimil does so is by acting selectively on tumor microvasculature to increase the local transvascular flow rate across the blood-brain tumor barrier. This mechanism of action does not explain why, in the clinical setting, carboplatin dosing based on patient renal function over-estimates the carboplatin dose required for target carboplatin exposure. In this study we investigated the systemic actions of labradimil, as well as other bradykinin B2 receptor agonists with a range of metabolic stabilities, in context of the local actions of the respective B2 receptor agonists on the blood-brain tumor barrier of rodent malignant gliomas. Methods Using dynamic contrast-enhanced MRI, the pharmacokinetics of gadolinium-diethyltriaminepentaacetic acid (Gd-DTPA, a small MRI contrast agent, were imaged in rodents bearing orthotopic RG-2 malignant gliomas. Baseline blood and brain tumor tissue pharmacokinetics were imaged with the 1st bolus of Gd-DTPA over the first hour, and then re-imaged with a 2nd bolus of Gd-DTPA over the second hour, during which normal saline or a bradykinin B2 receptor agonist was infused intravenously for 15 minutes. Changes in mean arterial blood pressure were recorded. Imaging data was analyzed using both qualitative and quantitative methods. Results The decrease in systemic blood pressure correlated with the known metabolic stability of the bradykinin B2 receptor agonist infused. Metabolically stable bradykinin B2 agonists, methionine-lysine-bradykinin and labradimil, had differential effects on the transvascular flow rate of Gd-DTPA across the blood-brain tumor barrier. Both methionine

  11. The Effects of Chloroquine-Resistant and Chloroquine-Sensitive Strains of Berghei on Rodent Hepatic Drug-Metabolizing Enzymes

    Science.gov (United States)

    1993-10-14

    fascioliasis and visceral leishmaniasis (Tekwani et al., 1988; Cha and Edwards, 1976: Hosts showed reduction of reductase. Facino et al...in bovine fascioliasis . Toxicology Letters 159 20,231-236. Feyereisen , R., J. F. Koener, D. E. Farnsworth, and D. W. Nebert. 1989. Isolation and...More, and M. France . 1983 . Impairment of drug metabolism by the liver in experimental fascioliasis in the rat . Journal of Pharmacy and

  12. In Vitro Drug Transfer Due to Drug Retention in Human Epidermis Pretreated with Application of Marketed Estradiol Transdermal Systems.

    Science.gov (United States)

    Krishnaiah, Yellela S R; Pavurala, Naresh; Yang, Yang; Manda, Prashanth; Katragadda, Usha; Yang, Yongsheng; Shah, Rakhi; Fang, Guodong; Khan, Mansoor A

    2017-08-01

    Study objective was to assess skin-to-skin drug transfer potential that may occur due to drug retention in human epidermis (DRE) pretreated with application of estradiol transdermal drug delivery systems (TDDS) and other estradiol transdermal dosage forms (gels and sprays). TDDS (products-A, B, and C) with varying formulation design and composition, and other estradiol transdermal products (gel and spray) were applied to heat separated human epidermis (HSE) and subjected to in vitro drug permeation study. Amounts of DRE were quantified after 24 h. The DRE with product-B was significantly (P  0.05) amounts of DRE. A separate in vitro permeation study was carried out to determine amounts of drug transferred from drug-retaining epidermis to untreated HSE. The amounts of drug transferred, due to DRE after 8 h, with product-C were significantly (P drug transfer due to the DRE after labeled period of using estradiol TDDS, though the clinical relevance of these findings is yet to be determined.

  13. Novel drug metabolism indices for pharmacogenetic functional status based on combinatory genotyping of CYP2C9, CYP2C19 and CYP2D6 genes

    Science.gov (United States)

    Villagra, David; Goethe, John; Schwartz, Harold I; Szarek, Bonnie; Kocherla, Mohan; Gorowski, Krystyna; Windemuth, Andreas; Ruaño, Gualberto

    2011-01-01

    Aims We aim to demonstrate clinical relevance and utility of four novel drug-metabolism indices derived from a combinatory (multigene) approach to CYP2C9, CYP2C19 and CYP2D6 allele scoring. Each index considers all three genes as complementary components of a liver enzyme drug metabolism system and uniquely benchmarks innate hepatic drug metabolism reserve or alteration through CYP450 combinatory genotype scores. Methods A total of 1199 psychiatric referrals were genotyped for polymorphisms in the CYP2C9, CYP2C19 and CYP2D6 gene loci and were scored on each of the four indices. The data were used to create distributions and rankings of innate drug metabolism capacity to which individuals can be compared. Drug-specific indices are a combination of the drug metabolism indices with substrate-specific coefficients. Results The combinatory drug metabolism indices proved useful in positioning individuals relative to a population with regard to innate drug metabolism capacity prior to pharmacotherapy. Drug-specific indices generate pharmacogenetic guidance of immediate clinical relevance, and can be further modified to incorporate covariates in particular clinical cases. Conclusions We believe that this combinatory approach represents an improvement over the current gene-by-gene reporting by providing greater scope while still allowing for the resolution of a single-gene index when needed. This method will result in novel clinical and research applications, facilitating the translation from pharmacogenomics to personalized medicine, particularly in psychiatry where many drugs are metabolized or activated by multiple CYP450 isoenzymes. PMID:21861665

  14. The human gut microbiota: metabolism and perspective in obesity.

    Science.gov (United States)

    Gomes, Aline Corado; Hoffmann, Christian; Mota, João Felipe

    2018-04-18

    The gut microbiota has been recognized as an important factor in the development of metabolic diseases such as obesity and is considered an endocrine organ involved in the maintenance of energy homeostasis and host immunity. Dysbiosis can change the functioning of the intestinal barrier and the gut-associated lymphoid tissues (GALT) by allowing the passage of structural components of bacteria, such as lipopolysaccharides (LPS), which activate inflammatory pathways that may contribute to the development of insulin resistance. Furthermore, intestinal dysbiosis can alter the production of gastrointestinal peptides related to satiety, resulting in an increased food intake. In obese people, this dysbiosis seems be related to increases of the phylum Firmicutes, the genus Clostridium, and the species Eubacterium rectale, Clostridium coccoides, Lactobacillus reuteri, Akkermansia muciniphila, Clostridium histolyticum, and Staphylococcus aureus.

  15. Critical assessment of human metabolic pathway databases: a stepping stone for future integration

    Directory of Open Access Journals (Sweden)

    Stobbe Miranda D

    2011-10-01

    Full Text Available Abstract Background Multiple pathway databases are available that describe the human metabolic network and have proven their usefulness in many applications, ranging from the analysis and interpretation of high-throughput data to their use as a reference repository. However, so far the various human metabolic networks described by these databases have not been systematically compared and contrasted, nor has the extent to which they differ been quantified. For a researcher using these databases for particular analyses of human metabolism, it is crucial to know the extent of the differences in content and their underlying causes. Moreover, the outcomes of such a comparison are important for ongoing integration efforts. Results We compared the genes, EC numbers and reactions of five frequently used human metabolic pathway databases. The overlap is surprisingly low, especially on reaction level, where the databases agree on 3% of the 6968 reactions they have combined. Even for the well-established tricarboxylic acid cycle the databases agree on only 5 out of the 30 reactions in total. We identified the main causes for the lack of overlap. Importantly, the databases are partly complementary. Other explanations include the number of steps a conversion is described in and the number of possible alternative substrates listed. Missing metabolite identifiers and ambiguous names for metabolites also affect the comparison. Conclusions Our results show that each of the five networks compared provides us with a valuable piece of the puzzle of the complete reconstruction of the human metabolic network. To enable integration of the networks, next to a need for standardizing the metabolite names and identifiers, the conceptual differences between the databases should be resolved. Considerable manual intervention is required to reach the ultimate goal of a unified and biologically accurate model for studying the systems biology of human metabolism. Our comparison

  16. Partitioning the Metabolic Cost of Human Running: A Task-by-Task Approach

    Science.gov (United States)

    Arellano, Christopher J.; Kram, Rodger

    2014-01-01

    Compared with other species, humans can be very tractable and thus an ideal “model system” for investigating the metabolic cost of locomotion. Here, we review the biomechanical basis for the metabolic cost of running. Running has been historically modeled as a simple spring-mass system whereby the leg acts as a linear spring, storing, and returning elastic potential energy during stance. However, if running can be modeled as a simple spring-mass system with the underlying assumption of perfect elastic energy storage and return, why does running incur a metabolic cost at all? In 1980, Taylor et al. proposed the “cost of generating force” hypothesis, which was based on the idea that elastic structures allow the muscles to transform metabolic energy into force, and not necessarily mechanical work. In 1990, Kram and Taylor then provided a more explicit and quantitative explanation by demonstrating that the rate of metabolic energy consumption is proportional to body weight and inversely proportional to the time of foot-ground contact for a variety of animals ranging in size and running speed. With a focus on humans, Kram and his colleagues then adopted a task-by-task approach and initially found that the metabolic cost of running could be “individually” partitioned into body weight support (74%), propulsion (37%), and leg-swing (20%). Summing all these biomechanical tasks leads to a paradoxical overestimation of 131%. To further elucidate the possible interactions between these tasks, later studies quantified the reductions in metabolic cost in response to synergistic combinations of body weight support, aiding horizontal forces, and leg-swing-assist forces. This synergistic approach revealed that the interactive nature of body weight support and forward propulsion comprises ∼80% of the net metabolic cost of running. The task of leg-swing at most comprises ∼7% of the net metabolic cost of running and is independent of body weight support and forward

  17. 78 FR 22270 - Joint Meeting of the Endocrinologic and Metabolic Drugs Advisory Committee and the Drug Safety...

    Science.gov (United States)

    2013-04-15

    ..., indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes... Evaluated for Cardiovascular Outcomes and Regulation of Glycemia in Diabetes (RECORD) trial, for new drug...

  18. Metabolomics by proton nuclear magnetic resonance spectroscopy of the response to chloroethylnitrosourea reveals drug efficacy and tumor adaptive metabolic pathways.

    Science.gov (United States)

    Morvan, Daniel; Demidem, Aicha

    2007-03-01

    Metabolomics of tumors may allow discovery of tumor biomarkers and metabolic therapeutic targets. Metabolomics by two-dimensional proton high-resolution magic angle spinning nuclear magnetic resonance spectroscopy was applied to investigate metabolite disorders following treatment by chloroethylnitrosourea of murine B16 melanoma (n = 33) and 3LL pulmonary carcinoma (n = 31) in vivo. Treated tumors of both types resumed growth after a delay. Nitrosoureas provoke DNA damage but the metabolic consequences of genotoxic stress are little known yet. Although some differences were observed in the metabolite profile of untreated tumor types, the prominent metabolic features of the response to nitrosourea were common to both. During the growth inhibition phase, there was an accumulation of glucose (more than x10; P < 0.05), glutamine (x3 to 4; P < 0.01), and aspartate (x2 to 5; P < 0.01). This response testified to nucleoside de novo synthesis down-regulation and drug efficacy. However, this phase also involved the increase in alanine (P < 0.001 in B16 melanoma), the decrease in succinate (P < 0.001), and the accumulation of serine-derived metabolites (glycine, phosphoethanolamine, and formate; P < 0.01). This response witnessed the activation of pathways implicated in energy production and resumption of nucleotide de novo synthesis, thus metabolic pathways of DNA repair and adaptation to treatment. During the growth recovery phase, it remained polyunsaturated fatty acid accumulation (x1.5 to 2; P < 0.05) and reduced utilization of glucose compared with glutamine (P < 0.05), a metabolic fingerprint of adaptation. Thus, this study provides the proof of principle that metabolomics of tumor response to an anticancer agent may help discover metabolic pathways of drug efficacy and adaptation to treatment.

  19. Cancer therapy leading to state of cancer metabolism depression for efficient operation of small dosage cytotoxic drugs

    Directory of Open Access Journals (Sweden)

    Ponizovskiy MR

    2015-04-01

    Full Text Available “Prolonged medical starvation” as the method of cancer therapy was borrowed from folk healers Omelchenko A and Breuss R. Author was convinced in efficiency of this method of cancer treatment via examination of cured patients and on own experience. The mechanism of this method of cancer therapy operates via Warburg effect targeting that promotes efficient cancer treatment with small cytotoxic drugs. Just it was described the mechanism of Warburg effect as well as mechanism transmutation of mitochondrial function in cancer metabolism which are exhibited in connection with operation of described method cancer therapy. There were described the biochemical and biophysical mechanisms of formations resistance to some cytotoxic drugs and recurrence cancer disease after disease remission which occur sometimes as result of treatment with great dosage of cytotoxic drugs. Also it was described the benefits of use the method “Prolonged medical starvation” with decreased dosage of cytotoxic drugs for cancer treatment. The significance of this work that it was substantiated the mechanism operation of combination “Prolonged medical starvation” with small dosages cytotoxic drugs of cancer treatment, which mechanism leads to prevention recurrence cancer disease and resistance to anticancer drugs in comparison with intensive anticancer chemotherapy with great dosages of cytotoxic drugs in cancer therapy. Also the offered concepts of cancer therapy mechanism gave possibility to explain mechanisms of some results of experiments eliminating the doubts of the authors these experiments.

  20. Vitamin D receptor and vitamin D metabolizing enzymes are expressed in the human male reproductive tract

    DEFF Research Database (Denmark)

    Blomberg Jensen, Martin; Nielsen, John E; Jørgensen, Anne

    2010-01-01

    , since it is not solely dependent on VDR expression, but also on cellular uptake of circulating VD and presence and activity of VD metabolizing enzymes. Expression of VD metabolizing enzymes has not previously been investigated in human testis and male reproductive tract. Therefore, we performed......The vitamin D receptor (VDR) is expressed in human testis, and vitamin D (VD) has been suggested to affect survival and function of mature spermatozoa. Indeed, VDR knockout mice and VD deficient rats show decreased sperm counts and low fertility. However, the cellular response to VD is complex...

  1. A Simplified Model of Human Alcohol Metabolism That Integrates Biotechnology and Human Health into a Mass Balance Team Project

    Science.gov (United States)

    Yang, Allen H. J.; Dimiduk, Kathryn; Daniel, Susan

    2011-01-01

    We present a simplified human alcohol metabolism model for a mass balance team project. Students explore aspects of engineering in biotechnology: designing/modeling biological systems, testing the design/model, evaluating new conditions, and exploring cutting-edge "lab-on-a-chip" research. This project highlights chemical engineering's impact on…

  2. Drug-DNA adducts as biomarkers for metabolic activation of the nitro-aromatic nitrogen mustard prodrug PR-104A.

    Science.gov (United States)

    Stornetta, Alessia; Deng, Kai-Cheng Kieren; Danielli, Sara; Liyanage, H D Sarath; Sturla, Shana J; Wilson, William R; Gu, Yongchuan

    2018-04-07

    PR-104A is a clinical-stage nitrogen mustard prodrug that is activated for DNA alkylation by reduction of a nitro group to the corresponding hydroxylamine (PR-104H) or amine (PR-104M). Metabolic reduction is catalysed by flavoreductases such as cytochrome P450 oxidoreductase (POR) under hypoxia, or by aldo-ketoreductase 1C3 (AKR1C3) independently of hypoxia. The unstable reduced metabolites are challenging to measure in biological samples, and biomarkers of the metabolic activation of PR-104A have not been used in the clinical evaluation of PR-104 to date. Here, we employ a selected reaction monitoring mass spectrometry assay for DNA crosslinks to assess the capacity of human cancer cells to bioactivate PR-104A. We also test whether the more abundant DNA monoadducts could be used for the same purpose. DNA monoadducts and crosslinks from PR-104A itself, and from its reduced metabolites, accumulated over 4 h in AKR1C3-expressing TF1 erythroleukaemia cells under hypoxia, whereas intracellular concentrations of unstable PR-104H and PR-104M reached steady state within 1 h. We then varied rates of PR-104A reduction by manipulating hypoxia or reductase expression in a panel of cell lines, in which AKR1C3 and POR were quantified by targeted proteomics. Hypoxia or reductase overexpression induced large increases in PR-104A sensitivity (inhibition of proliferation), DNA damage response (γH2AX formation), steady-state concentrations of PR-104H/M and formation of reduced drug-DNA adducts but not DNA adducts retaining the dinitro groups of PR-104A. The fold-change in the sum of PR-104H and PR-104M correlated with the fold-change in reduced crosslinks or monoadducts (R 2  = 0.87 for both), demonstrating their potential for assessing the capacity of cancer cells to bioactivate PR-104A. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. In silico drug metabolism and pharmacokinetic profiles of natural products from medicinal plants in the Congo basin.

    Science.gov (United States)

    Ntie-Kang, Fidele; Lifongo, Lydia L; Mbah, James A; Owono Owono, Luc C; Megnassan, Eugene; Mbaze, Luc Meva'a; Judson, Philip N; Sippl, Wolfgang; Efange, Simon M N

    2013-01-01

    Drug metabolism and pharmacokinetics (DMPK) assessment has come to occupy a place of interest during the early stages of drug discovery today. The use of computer modelling to predict the DMPK and toxicity properties of a natural product library derived from medicinal plants from Central Africa (named ConMedNP). Material from some of the plant sources are currently employed in African Traditional Medicine. Computer-based methods are slowly gaining ground in this area and are often used as preliminary criteria for the elimination of compounds likely to present uninteresting pharmacokinetic profiles and unacceptable levels of toxicity from the list of potential drug candidates, hence cutting down the cost of discovery of a drug. In the present study, we present an in silico assessment of the DMPK and toxicity profile of a natural product library containing ~3,200 compounds, derived from 379 species of medicinal plants from 10 countries in the Congo Basin forests and savannas, which have been published in the literature. In this analysis, we have used 46 computed physico-chemical properties or molecular descriptors to predict the absorption, distribution, metabolism and elimination and toxicity (ADMET) of the compounds. This survey demonstrated that about 45% of the compounds within the ConMedNP compound library are compliant, having properties which fall within the range of ADME properties of 95% of currently known drugs, while about 69% of the compounds have ≤ 2 violations. Moreover, about 73% of the compounds within the corresponding "drug-like" subset showed compliance. In addition to the verified levels of "drug-likeness", diversity and the wide range of measured biological activities, the compounds from medicinal plants in Central Africa show interesting DMPK profiles and hence could represent an important starting point for hit/lead discovery.

  4. Biofabrication of a three-dimensional liver micro-organ as an in vitro drug metabolism model

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Robert; Sun Wei [Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA (United States); Emami, Kamal; Wu Honglu, E-mail: rcc34@drexel.ed, E-mail: sunwei@drexel.ed, E-mail: kamal.emami-1@nasa.go, E-mail: honglu.wu-1@nasa.go [Radiation Biophysics Laboratory, Human Adaptation and Countermeasures Office, NASA Johnson Space Center, Houston, TX (United States)

    2010-12-15

    In their normal in vivo matrix milieu, tissues assume complex well-organized three-dimensional architectures. Therefore, the primary aim in the tissue engineering design process is to fabricate an optimal analog of the in vivo scenario. This challenge can be addressed by applying emerging layered biofabrication approaches in which the precise configuration and composition of cells and bioactive matrix components can recapitulate the well-defined three-dimensional biomimetic microenvironments that promote cell-cell and cell-matrix interactions. Furthermore, the advent of and refinements in microfabricated systems can present physical and chemical cues to cells in a controllable and reproducible fashion unmatched with conventional cultures, resulting in the precise construction of engineered biomimetic microenvironments on the cellular length scale in geometries that are readily parallelized for high throughput in vitro models. As such, the convergence of layered solid freeform fabrication (SFF) technologies along with microfabrication techniques enables the creation of a three-dimensional micro-organ device to serve as an in vitro platform for cell culture, drug screening or to elicit further biological insights, particularly for NASA's interest in a flight-suitable high-fidelity microscale platform to study drug metabolism in space and planetary environments. The proposed model in this paper involves the combinatorial setup of an automated syringe-based, layered direct cell writing bioprinting process with micro-patterning techniques to fabricate a microscale in vitro device housing a chamber of bioprinted three-dimensional liver cell-encapsulated hydrogel-based tissue constructs in defined design patterns that biomimic the cell's natural microenvironment for enhanced biological functionality. In order to assess the structural formability and biological feasibility of such a micro-organ, reproducibly fabricated tissue constructs were biologically

  5. Biofabrication of a three-dimensional liver micro-organ as an in vitro drug metabolism model.

    Science.gov (United States)

    Chang, Robert; Emami, Kamal; Wu, Honglu; Sun, Wei

    2010-12-01

    In their normal in vivo matrix milieu, tissues assume complex well-organized three-dimensional architectures. Therefore, the primary aim in the tissue engineering design process is to fabricate an optimal analog of the in vivo scenario. This challenge can be addressed by applying emerging layered biofabrication approaches in which the precise configuration and composition of cells and bioactive matrix components can recapitulate the well-defined three-dimensional biomimetic microenvironments that promote cell-cell and cell-matrix interactions. Furthermore, the advent of and refinements in microfabricated systems can present physical and chemical cues to cells in a controllable and reproducible fashion unmatched with conventional cultures, resulting in the precise construction of engineered biomimetic microenvironments on the cellular length scale in geometries that are readily parallelized for high throughput in vitro models. As such, the convergence of layered solid freeform fabrication (SFF) technologies along with microfabrication techniques enables the creation of a three-dimensional micro-organ device to serve as an in vitro platform for cell culture, drug screening or to elicit further biological insights, particularly for NASA's interest in a flight-suitable high-fidelity microscale platform to study drug metabolism in space and planetary environments. The proposed model in this paper involves the combinatorial setup of an automated syringe-based, layered direct cell writing bioprinting process with micro-patterning techniques to fabricate a microscale in vitro device housing a chamber of bioprinted three-dimensional liver cell-encapsulated hydrogel-based tissue constructs in defined design patterns that biomimic the cell's natural microenvironment for enhanced biological functionality. In order to assess the structural formability and biological feasibility of such a micro-organ, reproducibly fabricated tissue constructs were biologically characterized for

  6. Biofabrication of a three-dimensional liver micro-organ as an in vitro drug metabolism model

    International Nuclear Information System (INIS)

    Chang, Robert; Sun Wei; Emami, Kamal; Wu Honglu

    2010-01-01

    In their normal in vivo matrix milieu, tissues assume complex well-organized three-dimensional architectures. Therefore, the primary aim in the tissue engineering design process is to fabricate an optimal analog of the in vivo scenario. This challenge can be addressed by applying emerging layered biofabrication approaches in which the precise configuration and composition of cells and bioactive matrix components can recapitulate the well-defined three-dimensional biomimetic microenvironments that promote cell-cell and cell-matrix interactions. Furthermore, the advent of and refinements in microfabricated systems can present physical and chemical cues to cells in a controllable and reproducible fashion unmatched with conventional cultures, resulting in the precise construction of engineered biomimetic microenvironments on the cellular length scale in geometries that are readily parallelized for high throughput in vitro models. As such, the convergence of layered solid freeform fabrication (SFF) technologies along with microfabrication techniques enables the creation of a three-dimensional micro-organ device to serve as an in vitro platform for cell culture, drug screening or to elicit further biological insights, particularly for NASA's interest in a flight-suitable high-fidelity microscale platform to study drug metabolism in space and planetary environments. The proposed model in this paper involves the combinatorial setup of an automated syringe-based, layered direct cell writing bioprinting process with micro-patterning techniques to fabricate a microscale in vitro device housing a chamber of bioprinted three-dimensional liver cell-encapsulated hydrogel-based tissue constructs in defined design patterns that biomimic the cell's natural microenvironment for enhanced biological functionality. In order to assess the structural formability and biological feasibility of such a micro-organ, reproducibly fabricated tissue constructs were biologically characterized for

  7. Studies on the metabolism of five model drugs by fungi colonizing cadavers using LC-ESI-MS/MS and GC-MS analysis.

    Science.gov (United States)

    Martínez-Ramírez, Jorge A; Voigt, Kerstin; Peters, Frank T

    2012-09-01

    It is well-known that cadavers may be colonized by microorganisms, but there is limited information if or to what extent these microbes are capable of metabolizing drugs or poisons, changing the concentrations and metabolic pattern of such compounds in postmortem samples. The aim of the present study was to develop a fungal biotransformation system as an in vitro model to investigate potential postmortem metabolism by fungi. Five model drugs (amitriptyline, metoprolol, mirtazapine, promethazine, and zolpidem) were each incubated with five model fungi known to colonize cadavers (Absidia repens, Aspergillus repens, Aspergillus terreus, Gliocladium viride, and Mortierella polycephala) and with Cunninghamella elegans (positive control). Incubations were performed in Sabouraud medium at 25 °C for 5 days. After centrifugation, a part of the supernatants was analyzed by liquid chromatography-tandem mass spectrometry with product ion scanning. Another part was analyzed by full scan gas chromatography-mass spectrometry after extraction and derivatization. All model drugs were metabolized by the control fungus resulting in two (metoprolol) to ten (amitriptyline) metabolites. Of the model fungi, only Abs. repens and M. polycephala metabolized the model drugs: amitriptyline was metabolized to six and five, metoprolol to two and two, mirtazapine to five and three, promethazine to six and nine, and zolpidem to three and four metabolites, respectively. The main metabolic reactions were demethylation, oxidation, and hydroxylation. The presented in vitro model is applicable to studying drug metabolism by fungi colonizing cadavers.

  8. Mice with chimeric livers are an improved model for human lipoprotein metabolism.

    Science.gov (United States)

    Ellis, Ewa C S; Naugler, Willscott Edward; Nauglers, Scott; Parini, Paolo; Mörk, Lisa-Mari; Jorns, Carl; Zemack, Helen; Sandblom, Anita Lövgren; Björkhem, Ingemar; Ericzon, Bo-Göran; Wilson, Elizabeth M; Strom, Stephen C; Grompe, Markus

    2013-01-01

    Rodents are poor model for human hyperlipidemias because total cholesterol and low density lipoprotein levels are very low on a normal diet. Lipoprotein metabolism is primarily regulated by hepatocytes and we therefore assessed whether chimeric mice extensively repopulated with human cells can model human lipid and bile acid metabolism. FRG [ F ah(-/-) R ag2(-/-)Il2r g (-/-)]) mice were repopulated with primary human hepatocytes. Serum lipoprotein lipid composition and distribution (VLDL, LDL, and HDL) was analyzed by size exclusion chromatography. Bile was analyzed by LC-MS or by GC-MS. RNA expression levels were measured by quantitative RT-PCR. Chimeric mice displayed increased LDL and VLDL fractions and a lower HDL fraction compared to wild type, thus significantly shifting the ratio of LDL/HDL towards a human profile. Bile acid analysis revealed a human-like pattern with high amounts of cholic acid and deoxycholic acid (DCA). Control mice had only taurine-conjugated bile acids as expcted, but highly repopulated mice had glycine-conjugated cholic acid as found in human bile. RNA levels of human genes involved in bile acid synthesis including CYP7A1, and CYP27A1 were significantly upregulated as compared to human control liver. However, administration of recombinant hFGF19 restored human CYP7A1 levels to normal. Humanized-liver mice showed a typical human lipoprotein profile with LDL as the predominant lipoprotein fraction even on a normal diet. The bile acid profile confirmed presence of an intact enterohepatic circulation. Although bile acid synthesis was deregulated in this model, this could be fully normalized by FGF19 administration. Taken together these data indicate that chimeric FRG-mice are a useful new model for human lipoprotein and bile-acid metabolism.

  9. Multi-Copper Oxidases and Human Iron Metabolism

    Science.gov (United States)

    Vashchenko, Ganna; MacGillivray, Ross T. A.

    2013-01-01

    Multi-copper oxidases (MCOs) are a small group of enzymes that oxidize their substrate with the concomitant reduction of dioxygen to two water molecules. Generally, multi-copper oxidases are promiscuous with regards to their reducing substrates and are capable of performing various functions in different species. To date, three multi-copper oxidases have been detected in humans—ceruloplasmin, hephaestin and zyklopen. Each of these enzymes has a high specificity towards iron with the resulting ferroxidase activity being associated with ferroportin, the only known iron exporter protein in humans. Ferroportin exports iron as Fe2+, but transferrin, the major iron transporter protein of blood, can bind only Fe3+ effectively. Iron oxidation in enterocytes is mediated mainly by hephaestin thus allowing dietary iron to enter the bloodstream. Zyklopen is involved in iron efflux from placental trophoblasts during iron transfer from mother to fetus. Release of iron from the liver relies on ferroportin and the ferroxidase activity of ceruloplasmin which is found in blood in a soluble form. Ceruloplasmin, hephaestin and zyklopen show distinctive expression patterns and have unique mechanisms for regulating their expression. These features of human multi-copper ferroxidases can serve as a basis for the precise control of iron efflux in different tissues. In this manuscript, we review the biochemical and biological properties of the three human MCOs and discuss their potential roles in human iron homeostasis. PMID:23807651

  10. Tryptophan Biochemistry: Structural, Nutritional, Metabolic, and Medical Aspects in Humans.

    Science.gov (United States)

    Palego, Lionella; Betti, Laura; Rossi, Alessandra; Giannaccini, Gino

    2016-01-01

    L-Tryptophan is the unique protein amino acid (AA) bearing an indole ring: its biotransformation in living organisms contributes either to keeping this chemical group in cells and tissues or to breaking it, by generating in both cases a variety of bioactive molecules. Investigations on the biology of Trp highlight the pleiotropic effects of its small derivatives on homeostasis processes. In addition to protein turn-over, in humans the pathways of Trp indole derivatives cover the synthesis of the neurotransmitter/hormone serotonin (5-HT), the pineal gland melatonin (MLT), and the trace amine tryptamine. The breakdown of the Trp indole ring defines instead the "kynurenine shunt" which produces cell-response adapters as L-kynurenine, kynurenic and quinolinic acids, or the coenzyme nicotinamide adenine dinucleotide (NAD(+)). This review aims therefore at tracing a "map" of the main molecular effectors in human tryptophan (Trp) research, starting from the chemistry of this AA, dealing then with its biosphere distribution and nutritional value for humans, also focusing on some proteins responsible for its tissue-dependent uptake and biotransformation. We will thus underscore the role of Trp biochemistry in the pathogenesis of human complex diseases/syndromes primarily involving the gut, neuroimmunoendocrine/stress responses, and the CNS, supporting the use of -Omics approaches in this field.

  11. Comparison of TiO2 photocatalysis, electrochemically assisted Fenton reaction and direct electrochemistry for simulation of phase I metabolism reactions of drugs.

    Science.gov (United States)

    Ruokolainen, Miina; Gul, Turan; Permentier, Hjalmar; Sikanen, Tiina; Kostiainen, Risto; Kotiaho, Tapio

    2016-02-15

    The feasibility of titanium dioxide (TiO2) photocatalysis, electrochemically assisted Fenton reaction (EC-Fenton) and direct electrochemical oxidation (EC) for simulation of phase I metabolism of drugs was studied by comparing the reaction products of buspirone, promazine, testosterone and 7-ethoxycoumarin with phase I metabolites of the same compounds produced in vitro by human liver microsomes (HLM). Reaction products were analysed by UHPLC-MS. TiO2 photocatalysis simulated the in vitro phase I metabolism in HLM more comprehensively than did EC-Fenton or EC. Even though TiO2 photocatalysis, EC-Fenton and EC do not allow comprehensive prediction of phase I metabolism, all three methods produce several important metabolites without the need for demanding purification steps to remove the biological matrix. Importantly, TiO2 photocatalysis produces aliphatic and aromatic hydroxylation products where direct EC fails. Furthermore, TiO2 photocatalysis is an extremely rapid, simple and inexpensive way to generate oxidation products in a clean matrix and the reaction can be simply initiated and quenched by switching the UV lamp on/off. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Brain Insulin Resistance at the Crossroads of Metabolic and Cognitive Disorders in Humans.

    Science.gov (United States)

    Kullmann, Stephanie; Heni, Martin; Hallschmid, Manfred; Fritsche, Andreas; Preissl, Hubert; Häring, Hans-Ulrich

    2016-10-01

    Ever since the brain was identified as an insulin-sensitive organ, evidence has rapidly accumulated that insulin action in the brain produces multiple behavioral and metabolic effects, influencing eating behavior, peripheral metabolism, and cognition. Disturbances in brain insulin action can be observed in obesity and type 2 diabetes (T2D), as well as in aging and dementia. Decreases in insulin sensitivity of central nervous pathways, i.e., brain insulin resistance, may therefore constitute a joint pathological feature of metabolic and cognitive dysfunctions. Modern neuroimaging methods have provided new means of probing brain insulin action, revealing the influence of insulin on both global and regional brain function. In this review, we highlight recent findings on brain insulin action in humans and its impact on metabolism and cognition. Furthermore, we elaborate on the most prominent factors associated with brain insulin resistance, i.e., obesity, T2D, genes, maternal metabolism, normal aging, inflammation, and dementia, and on their roles regarding causes and consequences of brain insulin resistance. We also describe the beneficial effects of enhanced brain insulin signaling on human eating behavior and cognition and discuss potential applications in the treatment of metabolic and cognitive disorders. Copyright © 2016 the American Physiological Society.

  13. Probiotic modulation of symbiotic gut microbial–host metabolic interactions in a humanized microbiome mouse model

    Science.gov (United States)

    Martin, Francois-Pierre J; Wang, Yulan; Sprenger, Norbert; Yap, Ivan K S; Lundstedt, Torbjörn; Lek, Per; Rezzi, Serge; Ramadan, Ziad; van Bladeren, Peter; Fay, Laurent B; Kochhar, Sunil; Lindon, John C; Holmes, Elaine; Nicholson, Jeremy K

    2008-01-01

    The transgenomic metabolic effects of exposure to either Lactobacillus paracasei or Lactobacillus rhamnosus probiotics have been measured and mapped in humanized extended genome mice (germ-free mice colonized with human baby flora). Statistical analysis of the compartmental fluctuations in diverse metabolic compartments, including biofluids, tissue and cecal short-chain fatty acids (SCFAs) in relation to microbial population modulation generated a novel top-down systems biology view of the host response to probiotic intervention. Probiotic exposure exerted microbiome modification and resulted in altered hepatic lipid metabolism coupled with lowered plasma lipoprotein levels and apparent stimulated glycolysis. Probiotic treatments also altered a diverse range of pathways outcomes, including amino-acid metabolism, methylamines and SCFAs. The novel application of hierarchical-principal component analysis allowed visualization of multicompartmental transgenomic metabolic interactions that could also be resolved at the compartment and pathway level. These integrated system investigations demonstrate the potential of metabolic profiling as a top-down systems biology driver for investigating the mechanistic basis of probiotic action and the therapeutic surveillance of the gut microbial activity related to dietary supplementation of probiotics. PMID:18197175

  14. The human multidrug resistance-associated protein MRP is a plasma membrane drug-efflux pump

    NARCIS (Netherlands)

    Zaman, G. J.; Flens, M. J.; van Leusden, M. R.; de Haas, M.; Mülder, H. S.; Lankelma, J.; Pinedo, H. M.; Scheper, R. J.; Baas, F.; Broxterman, H. J.

    1994-01-01

    The multidrug-resistance associated protein MRP is a 180- to 195-kDa membrane protein associated with resistance of human tumor cells to cytotoxic drugs. We have investigated how MRP confers drug resistance in SW-1573 human lung carcinoma cells by generating a subline stably transfected with an

  15. Drugs associated with teratogenic mechanisms. Part II: a literature review of the evidence on human risks

    NARCIS (Netherlands)

    Gelder, M.M.H.J. van; Jong-van den Berg, L.T. de; Roeleveld, N.

    2014-01-01

    STUDY QUESTION: What is the current state of knowledge on the human risks of drugs suspected to be associated with teratogenic mechanisms? SUMMARY ANSWER: Evidence for the presence or absence of human risks of birth defects is scarce or non-existent for the majority of drugs associated with

  16. Application of a hierarchical enzyme classification method reveals the role of gut microbiome in human metabolism.

    Science.gov (United States)

    Mohammed, Akram; Guda, Chittibabu

    2015-01-01

    Enzymes are known as the molecular machines that drive the metabolism of an organism; hence identification of the full enzyme complement of an organism is essential to build the metabolic blueprint of that species as well as to understand the interplay of multiple species in an ecosystem. Experimental characterization of the enzymatic reactions of all enzymes in a genome is a tedious and expensive task. The problem is more pronounced in the metagenomic samples where even the species are not adequately cultured or characterized. Enzymes encoded by the gut microbiota play an essential role in the host metabolism; thus, warranting the need to accurately identify and annotate the full enzyme complements of species in the genomic and metagenomic projects. To fulfill this need, we develop and apply a method called ECemble, an ensemble approach to identify enzymes and enzyme classes and study the human gut metabolic pathways. ECemble method uses an ensemble of machine-learning methods to accurately model and predict enzymes from protein sequences and also identifies the enzyme classes and subclasses at the finest resolution. A tenfold cross-validation result shows accuracy between 97 and 99% at different levels in the hierarchy of enzyme classification, which is superior to comparable methods. We applied ECemble to predict the entire complements of enzymes from ten sequenced proteomes including the human proteome. We also applied this method to predict enzymes encoded by the human gut microbiome from gut metagenomic samples, and to study the role played by the microbe-derived enzymes in the human metabolism. After mapping the known and predicted enzymes to canonical human pathways, we identified 48 pathways that have at least one bacteria-encoded enzyme, which demonstrates the complementary role of gut microbiome in human gut metabolism. These pathways are primarily involved in metabolizing dietary nutrients such as carbohydrates, amino acids, lipids, cofactors and

  17. Application of a hierarchical enzyme classification method reveals the role of gut microbiome in human metabolism

    Science.gov (United States)

    2015-01-01

    Background Enzymes are known as the molecular machines that drive the metabolism of an organism; hence identification of the full enzyme complement of an organism is essential to build the metabolic blueprint of that species as well as to understand the interplay of multiple species in an ecosystem. Experimental characterization of the enzymatic reactions of all enzymes in a genome is a tedious and expensive task. The problem is more pronounced in the metagenomic samples where even the species are not adequately cultured or characterized. Enzymes encoded by the gut microbiota play an essential role in the host metabolism; thus, warranting the need to accurately identify and annotate the full enzyme complements of species in the genomic and metagenomic projects. To fulfill this need, we develop and apply a method called ECemble, an ensemble approach to identify enzymes and enzyme classes and study the human gut metabolic pathways. Results ECemble method uses an ensemble of machine-learning methods to accurately model and predict enzymes from protein sequences and also identifies the enzyme classes and subclasses at the finest resolution. A tenfold cross-validation result shows accuracy between 97 and 99% at different levels in the hierarchy of enzyme classification, which is superior to comparable methods. We applied ECemble to predict the entire complements of enzymes from ten sequenced proteomes including the human proteome. We also applied this method to predict enzymes encoded by the human gut microbiome from gut metagenomic samples, and to study the role played by the microbe-derived enzymes in the human metabolism. After mapping the known and predicted enzymes to canonical human pathways, we identified 48 pathways that have at least one bacteria-encoded enzyme, which demonstrates the complementary role of gut microbiome in human gut metabolism. These pathways are primarily involved in metabolizing dietary nutrients such as carbohydrates, amino acids, lipids

  18. Electrocatalytic oxidation of hydrogen peroxide on a platinum electrode in the imitation of oxidative drug metabolism of lidocaine.

    Science.gov (United States)

    Nouri-Nigjeh, Eslam; Bruins, Andries P; Bischoff, Rainer; Permentier, Hjalmar P

    2012-10-21

    Electrochemistry in combination with mass spectrometry has shown promise as a versatile technique not only in the analytical assessment of oxidative drug metabolism, but also for small-scale synthesis of drug metabolites. However, electrochemistry is generally limited to reactions initiated by direct electron transfer. In the case of substituted-aromatic compounds, oxidation proceeds through a Wheland-type intermediate where resonance stabilization of the positive charge determines the regioselectivity of the anodic substitution reaction, and hence limits the extent of generating drug metabolites in comparison with in vivo oxygen insertion reactions. In this study, we show that the electrocatalytic oxidation of hydrogen peroxide on a platinum electrode generates reactive oxygen species, presumably surface-bound platinum-oxo species, which are capable of oxygen insertion reactions in analogy to oxo-ferryl radical cations in the active site of Cytochrome P450. Electrochemical oxidation of lidocaine at constant potential in the presence of hydrogen peroxide produces both 3- and 4-hydroxylidocaine, suggesting reaction via an arene oxide rather than a Wheland-type intermediate. No benzylic hydroxylation was observed, thus freely diffusing radicals do not appear to be present. The results of the present study extend the possibilities of electrochemical imitation of oxidative drug metabolism to oxygen insertion reactions.

  19. Antifungal Resistance, Metabolic Routes as Drug Targets, and New Antifungal Agents: An Overview about Endemic Dimorphic Fungi

    Directory of Open Access Journals (Sweden)

    Juliana Alves Parente-Rocha

    2017-01-01

    Full Text Available Diseases caused by fungi can occur in healthy people, but immunocompromised patients are the major risk group for invasive fungal infections. Cases of fungal resistance and the difficulty of treatment make fungal infections a public health problem. This review explores mechanisms used by fungi to promote fungal resistance, such as the mutation or overexpression of drug targets, efflux and degradation systems, and pleiotropic drug responses. Alternative novel drug targets have been investigated; these include metabolic routes used by fungi during infection, such as trehalose and amino acid metabolism and mitochondrial proteins. An overview of new antifungal agents, including nanostructured antifungals, as well as of repositioning approaches is discussed. Studies focusing on the development of vaccines against antifungal diseases have increased in recent years, as these strategies can be applied in combination with antifungal therapy to prevent posttreatment sequelae. Studies focused on the development of a pan-fungal vaccine and antifungal drugs can improve the treatment of immunocompromised patients and reduce treatment costs.

  20. A new kinetic model for human iodine metabolism

    International Nuclear Information System (INIS)

    Ficken, V.J.; Allen, E.W.; Adams, G.D.

    1985-01-01

    A new kinetic model of iodine metabolism incorporating preferential organification of tyrosil (TYR) residues of thyroglobulin is developed and evaluated for euthyroid (n=5) and hyperthyroid (n=11) subjects. Iodine and peripheral T4 metabolims were measured with oral /sup 131/I-NaI and intravenous /sup 125/I-74 respectively. Data (obtained over 10 days) and kinetic model are analyzed using the SAAM27 program developed by Berman (1978). Compartment rate constants (mean rate per hour +- ISD) are tabulated in this paper. Thyroid and renal iodide clearance compare favorably with values reported in the literature. TYR rate constants were not unique; however, values obtained are within the range of rate constants determined from the invitro data reported by others. Intraluminal iodine as coupled TYR is predicted to be 21% for euthyroid and 59% for hyperthyroid subjects compared to analytical chemical methods of 30% and 51% respectively determined elsewhere. The authors plan to evaluate this model as a method of predicting the thyroid radiation dose from orally administered I/sup 131/

  1. Characterization of the Usage of the Serine Metabolic Network in Human Cancer

    Directory of Open Access Journals (Sweden)

    Mahya Mehrmohamadi

    2014-11-01

    Full Text Available The serine, glycine, one-carbon (SGOC metabolic network is implicated in cancer pathogenesis, but its general functions are unknown. We carried out a computational reconstruction of the SGOC network and then characterized its expression across thousands of cancer tissues. Pathways including methylation and redox metabolism exhibited heterogeneous expression indicating a strong context dependency of their usage in tumors. From an analysis of coexpression, simultaneous up- or downregulation of nucleotide synthesis, NADPH, and glutathione synthesis was found to be a common occurrence in all cancers. Finally, we developed a method to trace the metabolic fate of serine using stable isotopes, high-resolution mass spectrometry, and a mathematical model. Although the expression of single genes didn’t appear indicative of flux, the collective expression of several genes in a given pathway allowed for successful flux prediction. Altogether, these findings identify expansive and heterogeneous functions for the SGOC metabolic network in human cancer.

  2. Systems biology from micro-organisms to human metabolic diseases: the role of detailed kinetic models.

    Science.gov (United States)

    Bakker, Barbara M; van Eunen, Karen; Jeneson, Jeroen A L; van Riel, Natal A W; Bruggeman, Frank J; Teusink, Bas

    2010-10-01

    Human metabolic diseases are typically network diseases. This holds not only for multifactorial diseases, such as metabolic syndrome or Type 2 diabetes, but even when a single gene defect is the primary cause, where the adaptive response of the entire network determines the severity of disease. The latter may differ between individuals carrying the same mutation. Understanding the adaptive responses of human metabolism naturally requires a systems biology approach. Modelling of metabolic pathways in micro-organisms and some mammalian tissues has yielded many insights, qualitative as well as quantitative, into their control and regulation. Yet, even for a well-known pathway such as glycolysis, precise predictions of metabolite dynamics from experimentally determined enzyme kinetics have been only moderately successful. In the present review, we compare kinetic models of glycolysis in three cell types (African trypanosomes, yeast and skeletal muscle), evaluate their predictive power and identify limitations in our understanding. Although each of these models has its own merits and shortcomings, they also share common features. For example, in each case independently measured enzyme kinetic parameters were used as input. Based on these 'lessons from glycolysis', we will discuss how to make best use of kinetic computer models to advance our understanding of human metabolic diseases.

  3. Test systems in drug discovery for hazard identification and risk assessment of human drug-induced liver injury.

    Science.gov (United States)

    Weaver, Richard J; Betts, Catherine; Blomme, Eric A G; Gerets, Helga H J; Gjervig Jensen, Klaus; Hewitt, Philip G; Juhila, Satu; Labbe, Gilles; Liguori, Michael J; Mesens, Natalie; Ogese, Monday O; Persson, Mikael; Snoeys, Jan; Stevens, James L; Walker, Tracy; Park, B Kevin

    2017-07-01

    The liver is an important target for drug-induced toxicities. Early detection of hepatotoxic drugs requires use of well-characterized test systems, yet current knowledge, gaps and limitations of tests employed remains an important issue for drug development. Areas Covered: The current state of the science, understanding and application of test systems in use for the detection of drug-induced cytotoxicity, mitochondrial toxicity, cholestasis and inflammation is summarized. The test systems highlighted herein cover mostly in vitro and some in vivo models and endpoint measurements used in the assessment of small molecule toxic liabilities. Opportunities for research efforts in areas necessitating the development of specific tests and improved mechanistic understanding are highlighted. Expert Opinion: Use of in vitro test systems for safety optimization will remain a core activity in drug discovery. Substantial inroads have been made with a number of assays established for human Drug-induced Liver Injury. There nevertheless remain significant gaps with a need for improved in vitro tools and novel tests to address specific mechanisms of human Drug-Induced Liver Injury. Progress in these areas will necessitate not only models fit for application, but also mechanistic understanding of how chemical insult on the liver occurs in order to identify translational and quantifiable readouts for decision-making.

  4. Caffeine and human DNA metabolism: the magic and the mystery

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, William K.; Heffernan, Timothy P.; Beaulieu, Lea M.; Doherty, Sharon; Frank, Alexandra R.; Zhou Yingchun; Bryant, Miriam F.; Zhou Tong; Luche, Douglas D.; Nikolaishvili-Feinberg, Nana; Simpson, Dennis A.; Cordeiro-Stone, Marila

    2003-11-27

    The ability of caffeine to reverse cell cycle checkpoint function and enhance genotoxicity after DNA damage was examined in telomerase-expressing human fibroblasts. Caffeine reversed the ATM-dependent S and G2 checkpoint responses to DNA damage induced by ionizing radiation (IR), as well as the ATR- and Chk1-dependent S checkpoint response to ultraviolet radiation (UVC). Remarkably, under conditions in which IR-induced G2 delay was reversed by caffeine, IR-induced G1 arrest was not. Incubation in caffeine did not increase the percentage of cells entering the S phase 6-8 h after irradiation; ATM-dependent phosphorylation of p53 and transactivation of p21{sup Cip1/Waf1} post-IR were resistant to caffeine. Caffeine alone induced a concentration- and time-dependent inhibition of DNA synthesis. It inhibited the entry of human fibroblasts into S phase by 70-80% regardless of the presence or absence of wildtype ATM or p53. Caffeine also enhanced the inhibition of cell proliferation induced by UVC in XP variant fibroblasts. This effect was reversed by expression of DNA polymerase {eta}, indicating that translesion synthesis of UVC-induced pyrimidine dimers by DNA pol {eta} protects human fibroblasts against UVC genotoxic effects even when other DNA repair functions are compromised by caffeine.

  5. Caffeine and human DNA metabolism: the magic and the mystery

    International Nuclear Information System (INIS)

    Kaufmann, William K.; Heffernan, Timothy P.; Beaulieu, Lea M.; Doherty, Sharon; Frank, Alexandra R.; Zhou Yingchun; Bryant, Miriam F.; Zhou Tong; Luche, Douglas D.; Nikolaishvili-Feinberg, Nana; Simpson, Dennis A.; Cordeiro-Stone, Marila

    2003-01-01

    The ability of caffeine to reverse cell cycle checkpoint function and enhance genotoxicity after DNA damage was examined in telomerase-expressing human fibroblasts. Caffeine reversed the ATM-dependent S and G2 checkpoint responses to DNA damage induced by ionizing radiation (IR), as well as the ATR- and Chk1-dependent S checkpoint response to ultraviolet radiation (UVC). Remarkably, under conditions in which IR-induced G2 delay was reversed by caffeine, IR-induced G1 arrest was not. Incubation in caffeine did not increase the percentage of cells entering the S phase 6-8 h after irradiation; ATM-dependent phosphorylation of p53 and transactivation of p21 Cip1/Waf1 post-IR were resistant to caffeine. Caffeine alone induced a concentration- and time-dependent inhibition of DNA synthesis. It inhibited the entry of human fibroblasts into S phase by 70-80% regardless of the presence or absence of wildtype ATM or p53. Caffeine also enhanced the inhibition of cell proliferation induced by UVC in XP variant fibroblasts. This effect was reversed by expression of DNA polymerase η, indicating that translesion synthesis of UVC-induced pyrimidine dimers by DNA pol η protects human fibroblasts against UVC genotoxic effects even when other DNA repair functions are compromised by caffeine

  6. Metabolic profiling detects early effects of environmental and lifestyle exposure to cadmium in a human population

    Directory of Open Access Journals (Sweden)

    Ellis James K

    2012-06-01

    Full Text Available Abstract Background The 'exposome' represents the accumulation of all environmental exposures across a lifetime. Top-down strategies are required to assess something this comprehensive, and could transform our understanding of how environmental factors affect human health. Metabolic profiling (metabonomics/metabolomics defines an individual's metabolic phenotype, which is influenced by genotype, diet, lifestyle, health and xenobiotic exposure, and could also reveal intermediate biomarkers for disease risk that reflect adaptive response to exposure. We investigated changes in metabolism in volunteers living near a point source of environmental pollution: a closed zinc smelter with associated elevated levels of environmental cadmium. Methods High-resolution 1H NMR spectroscopy (metabonomics was used to acquire urinary metabolic profiles from 178 human volunteers. The spectral data were subjected to multivariate and univariate analysis to identify metabolites that were correlated with lifestyle or biological factors. Urinary levels of 8-oxo-deoxyguanosine were also measured, using mass spectrometry, as a marker of systemic oxidative stress. Results Six urinary metabolites, either associated with mitochondrial metabolism (citrate, 3-hydroxyisovalerate, 4-deoxy-erythronic acid or one-carbon metabolism (dimethylglycine, creatinine, creatine, were associated with cadmium exposure. In particular, citrate levels retained a significant correlation to urinary cadmium and smoking status after controlling for