1
|
Stoyanov S, Yancheva D, Velcheva E, Stamboliyska B. Anion and radical anion products of flutamide studied by IR spectra and density functional calculations. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2022.133927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
2
|
Penning TM, Su AL, El-Bayoumy K. Nitroreduction: A Critical Metabolic Pathway for Drugs, Environmental Pollutants, and Explosives. Chem Res Toxicol 2022; 35:1747-1765. [PMID: 36044734 PMCID: PMC9703362 DOI: 10.1021/acs.chemrestox.2c00175] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nitro group containing xenobiotics include drugs, cancer chemotherapeutic agents, carcinogens (e.g., nitroarenes and aristolochic acid) and explosives. The nitro group undergoes a six-electron reduction to form sequentially the nitroso-, N-hydroxylamino- and amino-functional groups. These reactions are catalyzed by nitroreductases which, rather than being enzymes with this sole function, are enzymes hijacked for their propensity to donate electrons to the nitro group either one at a time via a radical mechanism or two at time via the equivalent of a hydride transfer. These enzymes include: NADPH-dependent flavoenzymes (NADPH: P450 oxidoreductase, NAD(P)H-quinone oxidoreductase), P450 enzymes, oxidases (aldehyde oxidase, xanthine oxidase) and aldo-keto reductases. The hydroxylamino group once formed can undergo conjugation reactions with acetate or sulfate catalyzed by N-acetyltransferases or sulfotransferases, respectively, leading to the formation of intermediates containing a good leaving group which in turn can generate a nitrenium or carbenium ion for covalent DNA adduct formation. The intermediates in the reduction sequence are also prone to oxidation and produce reactive oxygen species. As a consequence, many nitro-containing xenobiotics can be genotoxic either by forming stable covalent adducts or by oxidatively damaging DNA. This review will focus on the general chemistry of nitroreduction, the enzymes responsible, the reduction of xenobiotic substrates, the regulation of nitroreductases, the ability of nitrocompounds to form DNA adducts and act as mutagens as well as some future directions.
Collapse
Affiliation(s)
| | | | - Karam El-Bayoumy
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Pennsylvania State University, Hershey, Pennsylvania 17033-2360, United States
| |
Collapse
|
3
|
Khan MF, Murphy CD. Nitroreduction of flutamide by Cunninghamella elegans NADPH: Cytochrome P450 reductase. Biochem Biophys Rep 2022; 29:101209. [PMID: 35097225 PMCID: PMC8783101 DOI: 10.1016/j.bbrep.2022.101209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 01/07/2022] [Accepted: 01/10/2022] [Indexed: 12/02/2022] Open
Abstract
The microbial model of mammalian drug metabolism, Cunninghamella elegans, has three cytochrome P450 reductase genes in its genome: g1631 (CPR_A), g4301 (CPR_B), and g7609 (CPR_C). The nitroreductase activity of the encoded enzymes was investigated via expression of the genes in the yeast Pichia pastoris X33. Whole cell assays with the recombinant yeast demonstrated that the reductases converted the anticancer drug flutamide to the nitroreduced metabolite that was also produced from the same substrate when incubated with human NADPH: cytochrome P450 reductase. The nitroreductase activity extended to other substrates such as the related drug nilutamide and the environmental contaminants 1-nitronaphthalene and 1,3-dinitronaphthalene. Comparative experiments with cell lysates of recombinant yeast were conducted under aerobic and reduced oxygen conditions and demonstrated that the reductases are oxygen sensitive. Three cytochrome P450 reductase genes from Cunninghamella elegans were heterologously expressed in Pichia pastoris. TThe enzymes displayed nitroreductase activity towards flutamide, which is analogous to human cytochrome P450 reductase. The enzymes are oxygen sensitive, which is also a property shared with the human enzyme. Other nitro-containing substrates can be reduced by the fungal enzymes.
Collapse
|
4
|
Pal R, Singh K, Khan SA, Chawla P, Kumar B, Akhtar MJ. Reactive metabolites of the anticonvulsant drugs and approaches to minimize the adverse drug reaction. Eur J Med Chem 2021; 226:113890. [PMID: 34628237 DOI: 10.1016/j.ejmech.2021.113890] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 09/01/2021] [Accepted: 09/29/2021] [Indexed: 12/22/2022]
Abstract
Several generations of antiepileptic drugs (AEDs) are available in the market for the treatment of seizures, but these are amalgamated with acute to chronic side effects. The most common side effects of AEDs are dose-related, but some are idiosyncratic adverse drug reactions (ADRs) that transpire due to the formation of reactive metabolite (RM) after the bioactivation process. Because of the adverse reactions patients usually discontinue the medication in between the treatment. The AEDs such as valproic acid, lamotrigine, phenytoin etc., can be categorized under such types because they form the RM which may prevail with life-threatening adverse effects or immune-mediated reactions. Hepatotoxicity, teratogenicity, cutaneous hypersensitivity, dizziness, addiction, serum sickness reaction, renal calculi, metabolic acidosis are associated with the metabolites of drugs such as arene oxide, N-desmethyldiazepam, 2-(1-hydroxyethyl)-2-methylsuccinimide, 2-(sulphamoy1acetyl)-phenol, E-2-en-VPA and 4-en-VPA and carbamazepine-10,11-epoxide, etc. The major toxicities are associated with the moieties that are either capable of forming RM or the functional groups may itself be too reactive prior to the metabolism. These functional groups or fragment structures are typically known as structural alerts or toxicophores. Therefore, minimizing the bioactivation potential of lead structures in the early phases of drug discovery by a modification to low-risk drug molecules is a priority for the pharmaceutical companies. Additionally, excellent potency and pharmacokinetic (PK) behaviour help in ensuring that appropriate (low dose) candidate drugs progress into the development phase. The current review discusses about RMs in the anticonvulsant drugs along with their mechanism vis-a-vis research efforts that have been taken to minimize the toxic effects of AEDs therapy.
Collapse
Affiliation(s)
- Rohit Pal
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Ghal Kalan, Ferozpur, G.T. Road, Moga, 142001, Punjab, India
| | - Karanvir Singh
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Ghal Kalan, Ferozpur, G.T. Road, Moga, 142001, Punjab, India
| | - Shah Alam Khan
- Department of Pharmaceutical Chemistry, College of Pharmacy, National University of Science and Technology, PO 620, PC 130, Azaiba, Bousher, Muscat, Oman
| | - Pooja Chawla
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Ghal Kalan, Ferozpur, G.T. Road, Moga, 142001, Punjab, India
| | - Bhupinder Kumar
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Ghal Kalan, Ferozpur, G.T. Road, Moga, 142001, Punjab, India.
| | - Md Jawaid Akhtar
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, Ghal Kalan, Ferozpur, G.T. Road, Moga, 142001, Punjab, India; Department of Pharmaceutical Chemistry, College of Pharmacy, National University of Science and Technology, PO 620, PC 130, Azaiba, Bousher, Muscat, Oman.
| |
Collapse
|
5
|
Ding Y, Ma H, Xu Y, Yang F, Li Y, Shi F, Lu Y. Potentiation of flutamide-induced hepatotoxicity in mice by Xian-Ling-Gu-Bao through induction of CYP1A2. JOURNAL OF ETHNOPHARMACOLOGY 2021; 278:114299. [PMID: 34090906 DOI: 10.1016/j.jep.2021.114299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/22/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Xian-Ling-Gu-Bao (XLGB) Fufang is herbal formula widely used to treat osteoporosis and other bone disorders. Because of its commonality in the clinical use, there is a safety concern over the use of XLGB combined with other androgen deprivation therapy (ADT) drugs such as flutamide (FLU) that is associated with reduced bone density. To date, there have been no evaluations on the side effects of the drug-drug interaction between XLGB and FLU. AIM OF THE STUDY The present study was designed to investigate the hepatotoxicity in the context of the combined treatment of XLGB and FLU in a mouse model, and to determine whether the metabolic activation of FLU through induction of CYP1A2 plays a role in the increased hepatoxicity caused by the combination of XLGB and FLU. MATERIALS AND METHODS C57 mice were administered with either XLGB (6,160 mg/kg), FLU (300 mg/kg), or with the combination of the two drugs. Animals were treated with XLGB for 5 days before the combined administration of XLGB and FLU for another 4 days. The serum of mice from single or the combined administration groups was collected for biochemical analysis. The mouse liver was collected to examine liver morphological changes, evaluate liver coefficient, as well as determine the mRNA expression of P450 isozymes (Cyp1a2, Cyp3a11 and Cyp2c37). For metabolism analysis, mice were treated with XLGB, FLU, or the combination of XLGB and FLU for 24 h. The urine samples were collected for the analysis of FLU-NAC conjugate by UPLC-Q-Orbitrap MS. The liver microsomes were prepared from fresh livers to determine the activity of metabolizing enzyme CYP1A2. RESULTS The combined treatment of XLGB and FLU caused loss of mice body weight and elicited significant liver toxicity as evidenced by an increased liver coefficient and serum lactate dehydrogenase (LDH) activity as well as pathological changes of fatty lesion of liver tissue. FLU increased hepatic expression of Cyp1a2 mRNA that was further elevated in the liver of mice when administered with both FLU and XLGB. Treatment of FLU resulted in an increase in the expression of Cyp3a11 mRNA that was negated when mice were co-treated with FLU and XLGB. No significant difference in Cyp2c37 mRNA expression was observed among the different treatment groups as compared to the control. Analysis of metabolic activity showed that the combined administration caused a synergic effect in elevating the activity of the CYP1A2 enzyme. Mass spectrometry analysis identified the presence of FLU reactive metabolite derived FLU-NAC conjugate in the urine of mice treated with FLU. Strikingly, about a two-fold increase of the FLU-NAC conjugate was detected when treated with both FLU and XLGB, indicating an elevated amount of toxic metabolite produced from FLU in the present of XLGB. CONCLUSION FLU and XLGB co-treatment potentiated FLU-induced hepatoxicity. This increased hepatoxicity was mediated through the induction of CYP1A2 activity which in turn enhanced bioactivation of FLU leading to over production of FLU-NAC conjugate and oxidative stress. These results offer warnings about serious side effects of the FLU-XLGB interaction in the clinical practice.
Collapse
Affiliation(s)
- Yannan Ding
- Key Laboratory of Basic Pharmacology of Ministry of Education, Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, 563003, China; Department of Pharmacy, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China
| | - Honghong Ma
- Key Laboratory of Basic Pharmacology of Ministry of Education, Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, 563003, China
| | - Yasha Xu
- Key Laboratory of Basic Pharmacology of Ministry of Education, Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, 563003, China
| | - Feng Yang
- Key Laboratory of Basic Pharmacology of Ministry of Education, Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, 563003, China
| | - Yi Li
- Key Laboratory of Basic Pharmacology of Ministry of Education, Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, 563003, China
| | - Fuguo Shi
- Key Laboratory of Basic Pharmacology of Ministry of Education, Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, 563003, China.
| | - Yuanfu Lu
- Key Laboratory of Basic Pharmacology of Ministry of Education, Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, 563003, China.
| |
Collapse
|
6
|
Umesh NM, Antolin Jesila J, Wang SF, Govindasamy M, Alshgari RA, Ouladsmane M, Asharani I. Fabrication of highly sensitive anticancer drug sensor based on heterostructured ZnO-Co3O4 capped on carbon nitride nanomaterials. Microchem J 2021. [DOI: 10.1016/j.microc.2021.106244] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
7
|
Nemeikaitė-Čėnienė A, Marozienė A, Misevičienė L, Tamulienė J, Yantsevich AV, Čėnas N. 5Flavoenzyme-catalyzed single-electron reduction of nitroaromatic antiandrogens: implications for their cytotoxicity. Free Radic Res 2021; 55:246-254. [PMID: 34098820 DOI: 10.1080/10715762.2021.1919304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The therapeutic action of nitroaromatic antiandrogens nilutamide and flutamide may be complicated by their cytotoxicity, whose mechanisms are still incomprehensively understood. In particular this concerns the enzymatic redox cycling of flutamide and its metabolites, and its impact on their cytotoxicity. In this work, we examined the single-electron reduction of nilutamide, flutamide, its metabolites 2-hydroxyflutamide and 4-nitro-3-trifluorormethyl-phenylamine, and a topical antiandrogen (3-amino-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl)-phenyl) propanamide by NADPH:cytochrome P-450 reductase and adrenodoxin reductase/adrenodoxin. The obtained steady-state bimolecular rate constants of oxidant reduction (kcat/Km) enabled to establish single-electron reduction midpoint potentials (E17) of compounds, -0.377 - -0.413 V, which were in line with enthalpies of formation of their free radicals, obtained by quantum mechanical calculations. Using murine hepatoma MH22a cells, the obtained cytotoxicity vs. E17 correlation based on the data of model nitroaromatic compounds shows that redox cycling and oxidative stress could be the main factor of cytotoxicity of nitroaromatic antiandrogens. Other minor cytotoxicity factors could be their redox metabolism involving NAD(P)H:quinone oxidoreductase (NQO1) and cytochromes P-450.
Collapse
Affiliation(s)
| | | | - Lina Misevičienė
- Institute of Biochemistry of Vilnius University, Vilnius, Lithuania
| | - Jelena Tamulienė
- Institute of Theoretical Physics and Astronomy of Vilnius University, Vilnius, Lithuania
| | | | - Narimantas Čėnas
- Institute of Biochemistry of Vilnius University, Vilnius, Lithuania
| |
Collapse
|
8
|
Kiiski I, Järvinen P, Ollikainen E, Jokinen V, Sikanen T. The material-enabled oxygen control in thiol-ene microfluidic channels and its feasibility for subcellular drug metabolism assays under hypoxia in vitro. LAB ON A CHIP 2021; 21:1820-1831. [PMID: 33949410 DOI: 10.1039/d0lc01292k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Tissue oxygen levels are known to be critical to regulation of many cellular processes, including the hepatic metabolism of therapeutic drugs, but its impact is often ignored in in vitro assays. In this study, the material-induced oxygen scavenging property of off-stoichiometric thiol-enes (OSTE) was exploited to create physiologically relevant oxygen concentrations in microfluidic immobilized enzyme reactors (IMERs) incorporating human liver microsomes. This could facilitate rapid screening of, for instance, toxic drug metabolites possibly produced in hypoxic conditions typical for many liver injuries. The mechanism of OSTE-induced oxygen scavenging was examined in depth to enable precise adjustment of the on-chip oxygen concentration with the help of microfluidic flow. The oxygen scavenging rate of OSTE was shown to depend on the type and the amount of the thiol monomer used in the bulk composition, and the surface-to-volume ratio of the chip design, but not on the physical or mechanical properties of the bulk. Our data suggest that oxygen scavenging takes place at the polymer-liquid interface, likely via oxidative reactions of the excess thiol monomers released from the bulk with molecular oxygen. Based on the kinetic constants governing the oxygen scavenging rate in OSTE microchannels, a microfluidic device comprising monolithically integrated oxygen depletion and IMER units was designed and its performance validated with the help of oxygen-dependent metabolism of an antiretroviral drug, zidovudine, which yields a cytotoxic metabolite under hypoxic conditions.
Collapse
Affiliation(s)
- Iiro Kiiski
- Faculty of Pharmacy, Drug Research Program, Division of Pharmaceutical Chemistry and Technology, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), Helsinki, FI-00014, Finland.
| | - Päivi Järvinen
- Faculty of Pharmacy, Drug Research Program, Division of Pharmaceutical Chemistry and Technology, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), Helsinki, FI-00014, Finland.
| | - Elisa Ollikainen
- Faculty of Pharmacy, Drug Research Program, Division of Pharmaceutical Chemistry and Technology, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), Helsinki, FI-00014, Finland.
| | - Ville Jokinen
- Department of Materials Science and Engineering, School of Chemical Engineering, Aalto University, Espoo, FI-02150, Finland
| | - Tiina Sikanen
- Faculty of Pharmacy, Drug Research Program, Division of Pharmaceutical Chemistry and Technology, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), Helsinki, FI-00014, Finland.
| |
Collapse
|
9
|
Tebby C, van der Voet H, de Sousa G, Rorije E, Kumar V, de Boer W, Kruisselbrink JW, Bois FY, Faniband M, Moretto A, Brochot C. A generic PBTK model implemented in the MCRA platform: Predictive performance and uses in risk assessment of chemicals. Food Chem Toxicol 2020; 142:111440. [PMID: 32473292 DOI: 10.1016/j.fct.2020.111440] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/07/2020] [Accepted: 05/15/2020] [Indexed: 12/13/2022]
Abstract
Physiologically-based toxicokinetic (PBTK) models are important tools for in vitro to in vivo or inter-species extrapolations in health risk assessment of foodborne and non-foodborne chemicals. Here we present a generic PBTK model implemented in the EuroMix toolbox, MCRA 9 and predict internal kinetics of nine chemicals (three endocrine disrupters, three liver steatosis inducers, and three developmental toxicants), in data-rich and data-poor conditions, when increasingly complex levels of parametrization are applied. At the first stage, only QSAR models were used to determine substance-specific parameters, then some parameter values were refined by estimates from substance-specific or high-throughput in vitro experiments. At the last stage, elimination or absorption parameters were calibrated based on available in vivo kinetic data. The results illustrate that parametrization plays a capital role in the output of the PBTK model, as it can change how chemicals are prioritized based on internal concentration factors. In data-poor situations, estimates can be far from observed values. In many cases of chronic exposure, the PBTK model can be summarized by an external to internal dose factor, and interspecies concentration factors can be used to perform interspecies extrapolation. We finally discuss the implementation and use of the model in the MCRA risk assessment platform.
Collapse
Affiliation(s)
- Cleo Tebby
- INERIS, Unit Models for Ecotoxicology and Toxicology (METO), Verneuil-en-Halatte, France.
| | | | | | - Emiel Rorije
- RIVM, Centre for Safety of Substances and Products, Department for Consumers and Product Safety, P.O. Box 1, 3720, BA Bilthoven, Netherlands
| | - Vikas Kumar
- URV, Universitat Rovira i Virgili, C/ Països Catalans, nº 26, 43007, Tarragona (Tarragona- Catalonia), Spain
| | - Waldo de Boer
- Wageningen University & Research, Biometris, Wageningen, Netherlands
| | | | - Frédéric Y Bois
- INERIS, Unit Models for Ecotoxicology and Toxicology (METO), Verneuil-en-Halatte, France
| | - Moosa Faniband
- Division of Occupational and Environmental Medicine, Faculty of Medicine, Lund University, Sweden
| | - Angelo Moretto
- Department of Biomedical and Clinical Sciences, Università degli Studi di Milano, Italy
| | - Céline Brochot
- INERIS, Unit Models for Ecotoxicology and Toxicology (METO), Verneuil-en-Halatte, France
| |
Collapse
|
10
|
Sharma RP, Kumar V, Schuhmacher M, Kolodkin A, Westerhoff HV. Development and evaluation of a harmonized whole body physiologically based pharmacokinetic (PBPK) model for flutamide in rats and its extrapolation to humans. ENVIRONMENTAL RESEARCH 2020; 182:108948. [PMID: 31841869 DOI: 10.1016/j.envres.2019.108948] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 10/25/2019] [Accepted: 11/17/2019] [Indexed: 06/10/2023]
Abstract
By their definition, inadvertent exposure to endocrine disrupting compounds (EDCs) intervenes with the endocrine signalling system, even at low dose. On the one hand, some EDCs are used as important pharmaceutical drugs that one would not want to dismiss. On the other hand, these pharmaceutical drugs are having off-target effects and increasingly significant exposure to the general population with unwanted health implications. Flutamide, one of the top pharmaceutical products marketed all over the world for the treatment of prostate cancer, is also a pollutant. Its therapeutic action mainly depends on targeting the androgen receptors and inhibiting the androgen action that is essential for growth and survival of prostate tissue. Currently flutamide is of concern with respect to its categorization as an endocrine disruptor. In this work we have developed a physiologically based pharmacokinetic (PBPK) model of flutamide that could serve as a standard tool for its human risk assessment. First we built the model for rat (where many parameters have been measured). The rat PBPK model was extrapolated to human where the re-parameterization involved human-specific physiology, metabolic kinetics derived from in-vitro studies, and the partition coefficient same as the rat model. We have harmonized the model by integrating different sets of in-vitro, in-vivo and physiological data into a PBPK model. Then the model was used to simulate different exposure scenarios and the results were compared against the observed data. Both uncertainty and sensitivity analysis was done. Since this new whole-body PBPK model can predict flutamide concentrations not only in plasma but also in various organs, the model may have clinical applications in efficacy and safety assessment of flutamide. The model can also be used for reverse dosimetry in the context of interpreting the available biomonitoring data to estimate the degree to which the population is currently being exposed, and a tool for the pharmaceutical companies to validate the estimated Permitted Daily Exposure (PDE) for flutamide.
Collapse
Affiliation(s)
- Raju Prasad Sharma
- Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007, Tarragona, Catalonia, Spain; Molecular Cell Physiology, VU University Amsterdam, the Netherlands; Infrastructure for Systems Biology Europe (ISBE), Europe
| | - Vikas Kumar
- Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007, Tarragona, Catalonia, Spain.
| | - Marta Schuhmacher
- Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007, Tarragona, Catalonia, Spain
| | - Alexey Kolodkin
- Molecular Cell Physiology, VU University Amsterdam, the Netherlands; Infrastructure for Systems Biology Europe (ISBE), Europe; Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Luxembourg
| | - Hans V Westerhoff
- Molecular Cell Physiology, VU University Amsterdam, the Netherlands; Infrastructure for Systems Biology Europe (ISBE), Europe; Synthetic Systems Biology and Nuclear Organization, Swammerdam Institute for Life Sciences, University of Amsterdam, the Netherlands; Manchester Centre for Integrative Systems Biology, UK.
| |
Collapse
|
11
|
Co-based heterogeneous catalysts from well-defined α-diimine complexes: Discussing the role of nitrogen. J Catal 2017. [DOI: 10.1016/j.jcat.2017.04.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
12
|
Teppner M, Boess F, Ernst B, Pahler A. Biomarkers of Flutamide-Bioactivation and Oxidative Stress In Vitro and In Vivo. Drug Metab Dispos 2016; 44:560-9. [DOI: 10.1124/dmd.115.066522] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 01/06/2016] [Indexed: 11/22/2022] Open
|
13
|
Teppner M, Böss F, Ernst B, Pähler A. Application of lipid peroxidation products as biomarkers for flutamide-induced oxidative stress in vitro. Toxicol Lett 2015; 238:53-9. [DOI: 10.1016/j.toxlet.2015.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 07/24/2015] [Accepted: 08/04/2015] [Indexed: 12/12/2022]
|
14
|
Wen B, Zhu M. Applications of mass spectrometry in drug metabolism: 50 years of progress. Drug Metab Rev 2015; 47:71-87. [DOI: 10.3109/03602532.2014.1001029] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
15
|
Brink A, Fontaine F, Marschmann M, Steinhuber B, Cece EN, Zamora I, Pähler A. Post-acquisition analysis of untargeted accurate mass quadrupole time-of-flight MS(E) data for multiple collision-induced neutral losses and fragment ions of glutathione conjugates. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:2695-2703. [PMID: 25380491 DOI: 10.1002/rcm.7062] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 09/23/2014] [Accepted: 09/23/2014] [Indexed: 06/04/2023]
Abstract
RATIONALE Analytical methods to assess glutathione (GSH) conjugate formation based on mass spectrometry usually take advantage of the specific fragmentation behavior of the glutathione moiety. However, most methods used for GSH adduct screening monitor only one specific neutral loss or one fragment ion, even though the peptide moiety of GSH adducts shows a number of other specific neutral fragments and fragment ions which can be used for identification. METHODS Nine reference drugs well known to form GSH adducts were incubated with human liver microsomes. Mass spectrometric analysis was performed with a quadrupole time-of-flight mass spectrometer in untargeted accurate mass MS(E) mode. The data analysis and evaluation was achieved in an automated approach with software to extract and identify GSH conjugates based on the presence of multiple collision-induced neutral losses and fragment ions specific for glutathione conjugates in the high-energy MS spectra. RESULTS In total 42 GSH adducts were identified. Eight (18%) adducts did not show the neutral loss of 129 but were identified based on the appearance of other GSH-specific neutral losses or fragment ions. In high-energy MS(E) spectra the GSH-specific fragment ions of m/z 308 and 179 as well as the neutral loss of 275 Da were complementary to the commonly used neutral loss of 129 Da. Further, one abundant (yet unpublished) GSH conjugate of troglitazone formed in human liver microsomes was found. CONCLUSIONS A software-aided approach was developed to reliably retrieve GSH adduct formation data out of untargeted complex full scan QTOFMS(E) data in a fast and efficient way. The present approach to detect and analyze multiple collision-induced neutral losses and fragment ions of glutathione conjugates in untargeted MS(E) data might be applicable to higher throughput to assess reactive metabolite formation in drug discovery.
Collapse
Affiliation(s)
- Andreas Brink
- Roche Pharmaceutical Research and Early Development, Drug Disposition and Safety, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 4070, Basel, Switzerland
| | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
This article provides a review of Sid Nelson's key contributions to the fields of drug metabolism and toxicology over a long and distinguished career. Selected examples are discussed to illustrate the diversity of Sid's research, with an emphasis on understanding mechanistic aspects of metabolic activation processes and structure-toxicity relationships. These examples serve to illustrate the importance of emerging mass spectrometry and isotope labeling techniques in elucidating details of foreign compound metabolism at the molecular level, an area in which Sid pioneered most effectively.
Collapse
Affiliation(s)
- Thomas A Baillie
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington , Seattle, WA , USA
| |
Collapse
|
17
|
Rajapakse A, Hillebrand R, Lewis SM, Parsons ZD, Barnes CL, Gates KS. Crystal structure of N-(quinolin-6-yl)hydroxyl-amine. Acta Crystallogr Sect E Struct Rep Online 2014; 70:322-324. [PMID: 25484734 PMCID: PMC4257318 DOI: 10.1107/s160053681402193x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 10/05/2014] [Indexed: 06/04/2023]
Abstract
The title compound, C9H8N2O, crystallized with four independent mol-ecules in the asymmetric unit. The four mol-ecules are linked via one O-H⋯N and two N-H⋯N hydrogen bonds, forming a tetra-mer-like unit. In the crystal, mol-ecules are further linked by O-H⋯N and N-H⋯O hydrogen bonds forming layers parallel to (001). These layers are linked via C-H⋯O hydrogen bonds and a number of weak C-H⋯π inter-actions, forming a three-dimensional structure. The crystal was refined as a non-merohedral twin with a minor twin component of 0.319.
Collapse
Affiliation(s)
| | - Roman Hillebrand
- 125 Chemistry Bldg, University of Missouri Columbia, MO 65211, USA
| | - Sarah M. Lewis
- 125 Chemistry Bldg, University of Missouri Columbia, MO 65211, USA
| | | | | | - Kent S. Gates
- 125 Chemistry Bldg, University of Missouri Columbia, MO 65211, USA
| |
Collapse
|
18
|
Johnson K, Parsons ZD, Barnes CL, Gates KS. Toward hypoxia-selective DNA-alkylating agents built by grafting nitrogen mustards onto the bioreductively activated, hypoxia-selective DNA-oxidizing agent 3-amino-1,2,4-benzotriazine 1,4-dioxide (tirapazamine). J Org Chem 2014; 79:7520-31. [PMID: 25029663 PMCID: PMC4136725 DOI: 10.1021/jo501252p] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Indexed: 12/14/2022]
Abstract
Tirapazamine (3-amino-1,2,4-benzotriazine 1,4-dioxide) is a heterocyclic di-N-oxide that undergoes enzymatic deoxygenation selectively in the oxygen-poor (hypoxic) cells found in solid tumors to generate a mono-N-oxide metabolite. This work explored the idea that the electronic changes resulting from the metabolic deoxygenation of tirapazamine analogues might be exploited to activate a DNA-alkylating species selectively in hypoxic tissue. Toward this end, tirapazamine analogues bearing nitrogen mustard units were prepared. In the case of the tirapazamine analogue 18a bearing a nitrogen mustard unit at the 6-position, it was found that removal of the 4-oxide from the parent di-N-oxide to generate the mono-N-oxide analogue 17a did indeed cause a substantial increase in reactivity of the mustard unit, as measured by hydrolysis rates and DNA-alkylation yields. Hammett sigma values were measured to quantitatively assess the magnitude of the electronic changes induced by metabolic deoxygenation of the 3-amino-1,2,4-benzotriazine 1,4-dioxide heterocycle. The results provide evidence that the 1,2,4-benzotiazine 1,4-dioxide unit can serve as an oxygen-sensing prodrug platform for the selective unmasking of bioactive agents in hypoxic cells.
Collapse
Affiliation(s)
- Kevin
M. Johnson
- Departments of Chemistry and Biochemistry, University of Missouri, 125 Chemistry Building, Columbia, Missouri 65211, United
States
| | - Zachary D. Parsons
- Departments of Chemistry and Biochemistry, University of Missouri, 125 Chemistry Building, Columbia, Missouri 65211, United
States
| | - Charles L. Barnes
- Departments of Chemistry and Biochemistry, University of Missouri, 125 Chemistry Building, Columbia, Missouri 65211, United
States
| | - Kent S. Gates
- Departments of Chemistry and Biochemistry, University of Missouri, 125 Chemistry Building, Columbia, Missouri 65211, United
States
| |
Collapse
|
19
|
Wen B, Roongta V, Liu L, Moore DJ. Metabolic activation of the indoloquinazoline alkaloids evodiamine and rutaecarpine by human liver microsomes: dehydrogenation and inactivation of cytochrome P450 3A4. Drug Metab Dispos 2014; 42:1044-54. [PMID: 24696463 DOI: 10.1124/dmd.114.057414] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Evodiamine and rutaecarpine are the main active indoloquinazoline alkaloids of the herbal medicine Evodia rutaecarpa, which is widely used for the treatment of hypertension, abdominal pain, angina pectoris, gastrointestinal disorder, and headache. Immunosuppressive effects and acute toxicity were reported in mice treated with evodiamine and rutaecarpine. Although the mechanism remains unknown, it is proposed that metabolic activation of the indoloquinazoline alkaloids and subsequent covalent binding of reactive metabolites to cellular proteins play a causative role. Liquid chromatography-tandem mass spectrometry analysis of incubations containing evodiamine and NADPH-supplemented microsomes in the presence of glutathione (GSH) revealed formation of a major GSH conjugate which was subsequently indentified as a benzylic thioether adduct on the C-8 position of evodiamine by NMR analysis. Several other GSH conjugates were also detected, including conjugates of oxidized and demethylated metabolites of evodiamine. Similar GSH conjugates were formed in incubations with rutaecarpine. These findings are consistent with a bioactivation sequence involving initial cytochrome P450-catalyzed dehydrogenation of the 3-alkylindole moiety in evodiamine and rutaecarpine to an electrophile 3-methyleneindolenine. Formation of the evodiamine and rutaecarpine GSH conjugates was primarily catalyzed by heterologously expressed recombinant CYP3A4 and, to a lesser extent, CYP1A2 and CYP2D6, respectively. It was found that the 3-methyleneindolenine or another reactive intermediate was a mechanism-based inactivator of CYP3A4, with inactivation parameters KI = 29 µM and kinact = 0.029 minute(-1), respectively. In summary, these findings are of significance in understanding the bioactivation mechanisms of indoloquinazoline alkaloids, and dehydrogenation of evodiamine and rutaecarpine may cause toxicities through formation of electrophilic intermediates and lead to drug-drug interactions mainly via CYP3A4 inactivation.
Collapse
Affiliation(s)
- Bo Wen
- Drug Metabolism, Non-Clinical Safety (B.W., L.L., D.J.M.) and Discovery Chemistry (V.R.), Hoffmann-La Roche, Nutley, New Jersey
| | | | | | | |
Collapse
|
20
|
Rajapakse A, Linder C, Morrison RD, Sarkar U, Leigh ND, Barnes CL, Daniels JS, Gates KS. Enzymatic conversion of 6-nitroquinoline to the fluorophore 6-aminoquinoline selectively under hypoxic conditions. Chem Res Toxicol 2013; 26:555-63. [PMID: 23488987 DOI: 10.1021/tx300483z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
There is substantial interest in small molecules that can be used to detect or kill the hypoxic (low oxygen) cells found in solid tumors. Nitroaryl moieties are useful components in the design of hypoxia-selective imaging agents and prodrugs because one-electron reductases can convert the nitroaryl group to nitroso, hydroxylamino, and amino metabolites selectively under low oxygen conditions. Here, we describe the in vitro, cell free metabolism of a pro-fluorescent substrate, 6-nitroquinoline (1) under both aerobic and hypoxic conditions. Both LC-MS and fluorescence spectroscopic analyses provided evidence that the one-electron reducing enzyme system, xanthine/xanthine oxidase, converted the nonfluorescent parent compound 1 to the known fluorophore 6-aminoquinoline (2) selectively under hypoxic conditions. The presumed intermediate in this reduction process, 6-hydroxylaminoquinoline (6), is fluorescent and can be efficiently converted by xanthine/xanthine oxidase to 2 only under hypoxic conditions. This finding provides evidence for multiple oxygen-sensitive steps in the enzymatic conversion of nitroaryl compounds to the corresponding amino derivatives. In a side reaction that is separate from the bioreductive metabolism of 1, xanthine oxidase converted 1 to 6-nitroquinolin-2(1H)-one (5). These studies may enable the use of 1 as a fluorescent substrate for the detection and profiling of one-electron reductases in cell culture or biopsy samples. In addition, the compound may find use as a fluorogenic probe for the detection of hypoxia in tumor models. The occurrence of side products such as 5 in the enzymatic bioreduction of 1 underscores the importance of metabolite identification in the characterization of hypoxia-selective probes and drugs that employ nitroaryl units as oxygen sensors.
Collapse
Affiliation(s)
- Anuruddha Rajapakse
- Department of Chemistry, University of Missouri , 125 Chemistry Building, Columbia, Missouri 65211, United States
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Rajapakse A, Gates KS. Hypoxia-selective, enzymatic conversion of 6-nitroquinoline into a fluorescent helicene: pyrido[3,2-f]quinolino[6,5-c]cinnoline 3-oxide. J Org Chem 2012; 77:3531-7. [PMID: 22417220 DOI: 10.1021/jo3004748] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Regions of low oxygen concentration (hypoxia) occur in both normal human physiology and under pathophysiological conditions. Fluorescent probes for the direct imaging of cellular hypoxia could be useful tools that complement radiochemical imaging and immunohistochemical staining methods. In this work, we set out to characterize the hypoxia-selective enzymatic metabolism of a simple nitroaryl probe, 6-nitroquinoline (1). We envisioned that this compound might undergo hypoxia-selective, bioreductive conversion to the fluorescent product, 6-aminoquinoline (2). The probe 1 was, indeed, converted to a fluorescent product selectively under hypoxic conditions by the one-electron reducing enzyme NADPH:cytochrome P450 reductase. However, inspection of the fluorescence spectrum and LC-MS analysis of the reaction mixture revealed that the expected product 2 was not formed. Rather, the 63-fold increase in fluorescence emission at 445 nm resulting from the hypoxic metabolism of 1 was due to formation of the azoxy-helicene product, pyrido[3,2-f]quinolino[6,5-c]cinnoline 3-oxide (4). The generation of 4 involves an unusual biaryl bond formation under reductive conditions. The mechanism of this process remains uncertain but could proceed via combination of a nitroaryl radical anion with a neutral nitrosoaryl radical, followed by tautomerization and intramolecular condensation between the resulting hydroxylamine and nitroso functional groups. Bioreductive metabolism of nitroaryl compounds represents a promising strategy for the selective delivery of cytotoxic agents and fluorescent markers to hypoxic tissue, but the results described here provide an important glimpse of the chemical complexity that can be associated with the enzymatic one-electron reduction of nitroaryl compounds.
Collapse
Affiliation(s)
- Anuruddha Rajapakse
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, Missouri 65211, USA
| | | |
Collapse
|
22
|
Havemeyer A, Lang J, Clement B. The fourth mammalian molybdenum enzyme mARC: current state of research. Drug Metab Rev 2011; 43:524-39. [DOI: 10.3109/03602532.2011.608682] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
23
|
Abstract
It is generally believed that metabolic bioactivation of drug molecules to form reactive metabolites, followed by their covalent binding to endogenous macromolecules, is one of the mechanisms that can lead to hepatotoxicity or idiosyncratic adverse drug reactions (IADRs). Although the role of bioactivation in drug-induced liver injury has been reasonably well established and accepted, and methodologies (e.g., structural alerts, reactive metabolite trapping, and covalent binding) continue to emerge in an attempt to detect the occurrence of bioactivation, the challenge remains to accurately predict the likelihood for idiosyncratic liver toxicity. Recent advances in risk-assessment methodologies, such as by the estimate of total body burden of covalent binding or by zone classification, taking the clinical dose into consideration, are positive steps toward improving risk assessment. The ability to better predict the potential of a drug candidate to cause IADRs will further be dependent upon a better understanding of the pathophysiological mechanisms of such reactions. Until a thorough understanding of the relationship between liver toxicity and the formation of reactive metabolites is achieved, it appears, at present, that the most practical strategy in drug discovery and development to reduce the likelihood of idiosyncratic liver toxicity via metabolic activation is to minimize or eliminate the occurrence of bioactivation and, at the same time, to maximize the pharmacological potency (to minimze the clinical dose) of the drug of interest.
Collapse
Affiliation(s)
- Louis Leung
- Pharmacokinetics, Dynamics, and Metabolism Department, Pfizer Global Research and Development, Groton, Connecticut 06340-5196, USA.
| | | | | |
Collapse
|
24
|
Loginova N, Koval’chuk T, Faletrov Y, Halauko Y, Osipovich N, Polozov G, Zheldakova R, Gres A, Halauko A, Azarko I, Shkumatov V, Shadyro O. Redox-active metal(II) complexes of sterically hindered phenolic ligands: Antibacterial activity and reduction of cytochrome c. Part II. Metal(II) complexes of o-diphenol derivatives of thioglycolic acid. Polyhedron 2011. [DOI: 10.1016/j.poly.2011.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
25
|
Stepan AF, Walker DP, Bauman J, Price DA, Baillie TA, Kalgutkar AS, Aleo MD. Structural alert/reactive metabolite concept as applied in medicinal chemistry to mitigate the risk of idiosyncratic drug toxicity: a perspective based on the critical examination of trends in the top 200 drugs marketed in the United States. Chem Res Toxicol 2011; 24:1345-410. [PMID: 21702456 DOI: 10.1021/tx200168d] [Citation(s) in RCA: 488] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Because of a preconceived notion that eliminating reactive metabolite (RM) formation with new drug candidates could mitigate the risk of idiosyncratic drug toxicity, the potential for RM formation is routinely examined as part of lead optimization efforts in drug discovery. Likewise, avoidance of "structural alerts" is almost a norm in drug design. However, there is a growing concern that the perceived safety hazards associated with structural alerts and/or RM screening tools as standalone predictors of toxicity risks may be over exaggerated. In addition, the multifactorial nature of idiosyncratic toxicity is now well recognized based upon observations that mechanisms other than RM formation (e.g., mitochondrial toxicity and inhibition of bile salt export pump (BSEP)) also can account for certain target organ toxicities. Hence, fundamental questions arise such as: When is a molecule that contains a structural alert (RM positive or negative) a cause for concern? Could the molecule in its parent form exert toxicity? Can a low dose drug candidate truly mitigate metabolism-dependent and -independent idiosyncratic toxicity risks? In an effort to address these questions, we have retrospectively examined 68 drugs (recalled or associated with a black box warning due to idiosyncratic toxicity) and the top 200 drugs (prescription and sales) in the United States in 2009 for trends in physiochemical characteristics, daily doses, presence of structural alerts, evidence for RM formation as well as toxicity mechanism(s) potentially mediated by parent drugs. Collectively, our analysis revealed that a significant proportion (∼78-86%) of drugs associated with toxicity contained structural alerts and evidence indicating that RM formation as a causative factor for toxicity has been presented in 62-69% of these molecules. In several cases, mitochondrial toxicity and BSEP inhibition mediated by parent drugs were also noted as potential causative factors. Most drugs were administered at daily doses exceeding several hundred milligrams. There was no obvious link between idiosyncratic toxicity and physicochemical properties such as molecular weight, lipophilicity, etc. Approximately half of the top 200 drugs for 2009 (prescription and sales) also contained one or more alerts in their chemical architecture, and many were found to be RM-positive. Several instances of BSEP and mitochondrial liabilities were also noted with agents in the top 200 category. However, with relatively few exceptions, the vast majority of these drugs are rarely associated with idiosyncratic toxicity, despite years of patient use. The major differentiating factor appeared to be the daily dose; most of the drugs in the top 200 list are administered at low daily doses. In addition, competing detoxication pathways and/or alternate nonmetabolic clearance routes provided suitable justifications for the safety records of RM-positive drugs in the top 200 category. Thus, while RM elimination may be a useful and pragmatic starting point in mitigating idiosyncratic toxicity risks, our analysis suggests a need for a more integrated screening paradigm for chemical hazard identification in drug discovery. Thus, in addition to a detailed assessment of RM formation potential (in relationship to the overall elimination mechanisms of the compound(s)) for lead compounds, effects on cellular health (e.g., cytotoxicity assays), BSEP inhibition, and mitochondrial toxicity are the recommended suite of assays to characterize compound liabilities. However, the prospective use of such data in compound selection will require further validation of the cellular assays using marketed agents. Until we gain a better understanding of the pathophysiological mechanisms associated with idiosyncratic toxicities, improving pharmacokinetics and intrinsic potency as means of decreasing the dose size and the associated "body burden" of the parent drug and its metabolites will remain an overarching goal in drug discovery.
Collapse
Affiliation(s)
- Antonia F Stepan
- Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, Connecticut 06340, USA
| | | | | | | | | | | | | |
Collapse
|
26
|
Roth RA, Ganey PE. Animal models of idiosyncratic drug-induced liver injury—Current status. Crit Rev Toxicol 2011; 41:723-39. [DOI: 10.3109/10408444.2011.575765] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
27
|
Wen B, Moore DJ. Bioactivation of glafenine by human liver microsomes and peroxidases: identification of electrophilic iminoquinone species and GSH conjugates. Drug Metab Dispos 2011; 39:1511-21. [PMID: 21628497 DOI: 10.1124/dmd.111.039396] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glafenine (Privadol; 2,3-dihydroxypropyl 2-[(7-chloro-4-quinolinyl) amino]benzoate) is a non-narcotic analgesic agent widely used for the treatment of pains of various origins. Severe liver toxicity and a high incidence of anaphylaxis were reported in patients treated with glafenine, eventually leading to its withdrawal from the market in most countries. It is proposed that bioactivation of glafenine and subsequent binding of reactive metabolite(s) to critical cellular proteins play a causative role. The study described herein aimed at characterizing pathways of glafenine bioactivation and the metabolic enzymes involved. Two GSH conjugates of glafenine were detected in human liver microsomal incubations using liquid chromatography tandem mass spectrometry. The structures of detected conjugates were determined as GSH adducts of 5-hydroxyglafenine (M3) and 5-hydroxy glafenic acid (M4), respectively. GSH conjugation took place with a strong preference at C6 of the benzene ring of glafenine, ortho to the carbonyl moiety. These findings are consistent with a bioactivation sequence involving initial cytochrome P450-catalyzed 5-hydroxylation of the benzene ring of glafenine, followed by two electron oxidations of M3 and M4 to form corresponding para-quinone imine intermediates that react with GSH to form GSH adducts M1 and M2, respectively. Formation of M1 and M2 was primarily catalyzed by heterologously expressed recombinant CYP3A4 and to a lesser extent, CYP2C19 and CYP2D6. We demonstrated that M3 can also be bioactivated by peroxidases, such as horseradish peroxidase and myeloperoxidase. In summary, these findings have significance in understanding the bioactivation pathways of glafenine and their potential link to mechanisms of toxicity of glafenine.
Collapse
Affiliation(s)
- Bo Wen
- Drug Metabolism, eADME, Non-Clinical Safety, Hoffmann-La Roche, Inc., 340 Kingsland Street, 123/1341, Nutley, NJ 07110, USA.
| | | |
Collapse
|
28
|
Park BK, Boobis A, Clarke S, Goldring CEP, Jones D, Kenna JG, Lambert C, Laverty HG, Naisbitt DJ, Nelson S, Nicoll-Griffith DA, Obach RS, Routledge P, Smith DA, Tweedie DJ, Vermeulen N, Williams DP, Wilson ID, Baillie TA. Managing the challenge of chemically reactive metabolites in drug development. Nat Rev Drug Discov 2011; 10:292-306. [DOI: 10.1038/nrd3408] [Citation(s) in RCA: 355] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
29
|
Nath A, Zientek MA, Burke BJ, Jiang Y, Atkins WM. Quantifying and predicting the promiscuity and isoform specificity of small-molecule cytochrome P450 inhibitors. Drug Metab Dispos 2010; 38:2195-203. [PMID: 20841376 DOI: 10.1124/dmd.110.034645] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Drug promiscuity (i.e., inhibition of multiple enzymes by a single compound) is increasingly recognized as an important pharmacological consideration in the drug development process. However, systematic studies of functional or physicochemical characteristics that correlate with drug promiscuity are handicapped by the lack of a good way of quantifying promiscuity. In this article, we present a new entropy-based index of drug promiscuity. We apply this index to two high-throughput data sets describing inhibition of cytochrome P450 isoforms by small-molecule drugs and drug candidates, and we demonstrate how drug promiscuity or specificity can be quantified. For these drug-metabolizing enzymes, we find that there is essentially no correlation between a drug's potency and specificity. We also present an index to quantify the susceptibilities of different enzymes to inhibition by diverse substrates. Finally, we use partial least-squares regression to successfully predict isoform specificity and promiscuity of small molecules, using a set of fingerprint-based descriptors.
Collapse
Affiliation(s)
- Abhinav Nath
- Department of Molecular Biophysics & Biochemistry, Yale University, P.O. Box 208114, New Haven, CT 06520-8114, USA.
| | | | | | | | | |
Collapse
|
30
|
Herath W, Khan IA. Microbial Metabolism. Part 11. Metabolites of Flutamide. Chem Pharm Bull (Tokyo) 2010; 58:562-4. [DOI: 10.1248/cpb.58.562] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Wimal Herath
- National Center for Natural Products Research, The University of Mississippi
| | - Ikhlas Ahmad Khan
- National Center for Natural Products Research, The University of Mississippi
- Department of Pharmacognosy, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi
| |
Collapse
|
31
|
Kashimshetty R, Desai VG, Kale VM, Lee T, Moland CL, Branham WS, New LS, Chan EC, Younis H, Boelsterli UA. Underlying mitochondrial dysfunction triggers flutamide-induced oxidative liver injury in a mouse model of idiosyncratic drug toxicity. Toxicol Appl Pharmacol 2009; 238:150-9. [DOI: 10.1016/j.taap.2009.05.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 04/20/2009] [Accepted: 05/04/2009] [Indexed: 12/14/2022]
|
32
|
Wen B, Fitch WL. Analytical strategies for the screening and evaluation of chemically reactive drug metabolites. Expert Opin Drug Metab Toxicol 2009; 5:39-55. [PMID: 19236228 DOI: 10.1517/17425250802665706] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Metabolic activation leading to formation of chemically reactive drug metabolites is a long-standing issue for drug development inasmuch as some, but not all, reactive intermediates play a role as mediators of drug-induced toxicities. The risk assessment profile/decision-making guide requires a comprehensive understanding of bioactivation mechanism(s), quantitative magnitude and cellular consequences of this principal and continued safety attrition. OBJECTIVE To evaluate analytical methodologies with improved sensitivity, selectivity and throughput for the analysis of reactive metabolites. CONCLUSIONS Identification and quantification of short-lived electrophilic intermediates through appropriate trapping experiments have become relatively straightforward. Minimizing the bioactivation potential of drug candidates during the discovery/lead optimization phase has been adopted as a default strategy. Together with advances of proteomics, metabolomics and toxicogenomics, an integrated multitier approach possibly provides a deeper insight into mechanistic aspects of drug-induced toxicities, and contributes to bridging the relationships between metabolic activation, drug-protein adduct formation and their toxicological consequences.
Collapse
Affiliation(s)
- Bo Wen
- Department of Drug Metabolism and Pharmacokinetics, Roche Palo Alto, Palo Alto, CA 94304, USA.
| | | |
Collapse
|
33
|
Bell SC, Gayton-Ely M, Nida CM. Bioassays for bomb-makers: proof of concept. Anal Bioanal Chem 2009; 395:401-9. [PMID: 19484462 DOI: 10.1007/s00216-009-2851-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Revised: 04/29/2009] [Accepted: 05/12/2009] [Indexed: 11/29/2022]
Abstract
Clandestine bomb-makers are exposed to significant amounts of explosives and allied materials. As with any ingested xenobiotic substance, these compounds are subject to biotransformation. As such, the potential exists that characteristic suites of biomarkers may be produced and deposited in matrices that can be exploited for forensic and investigative purposes. However, before such assays can be developed, foundational data must be gathered regarding the toxicokinetics, fate, and transport of the resulting biomarkers within the body and in matrices such as urine, hair, nails, sweat, feces, and saliva. This report presents an in vitro method for simulation of human metabolic transformations using human liver microsomes and an assay applicable to representative nitro-explosives. Control and metabolized samples of TNT, RDX, HMX, and tetryl were analyzed using high-performance liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) and biomarkers identified for each. The challenges associated with this method arise from solubility issues and limitations imposed by instrumentation, specifically, modes of ionization.
Collapse
Affiliation(s)
- Suzanne C Bell
- Forensic Science & Chemistry, West Virginia University, 1600 University Avenue, Oglebay Hall, Room 208, Box 6121, Morgantown, WV 26506-6121, USA.
| | | | | |
Collapse
|
34
|
Chapter 3 Applications of Quadrupole-Linear Ion Trap Mass Spectrometry to the Analysis of Reactive Metabolites in Drug Discovery and Development. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s1872-0854(09)00003-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|