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Mbaba M, Golding TM, Omondi RO, Mohunlal R, Egan TJ, Reader J, Birkholtz LM, Smith GS. Exploring the modulatory influence on the antimalarial activity of amodiaquine using scaffold hybridisation with ferrocene integration. Eur J Med Chem 2024; 271:116429. [PMID: 38663284 DOI: 10.1016/j.ejmech.2024.116429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 04/13/2024] [Accepted: 04/15/2024] [Indexed: 05/13/2024]
Abstract
Amodiaquine (AQ) is a potent antimalarial drug used in combination with artesunate as part of artemisinin-based combination therapies (ACTs) for malarial treatment. Due to the rising emergence of resistant malaria parasites, some of which have been reported for ACT, the usefulness of AQ as an efficacious therapeutic drug is threatened. Employing the organometallic hybridisation approach, which has been shown to restore the antimalarial activity of chloroquine in the form of an organometallic hybrid clinical candidate ferroquine (FQ), the present study utilises this strategy to modulate the biological performance of AQ by incorporating ferrocene. Presently, we have conceptualised ferrocenyl AQ derivatives and have developed facile, practical routes for their synthesis. A tailored library of AQ derivatives was assembled and their antimalarial activity evaluated against chemosensitive (NF54) and multidrug-resistant (K1) strains of the malaria parasite, Plasmodium falciparum. The compounds generally showed enhanced or comparable activities to those of the reference clinical drugs chloroquine and AQ, against both strains, with higher selectivity for the sensitive phenotype, mostly in the double-digit nanomolar IC50 range. Moreover, representative compounds from this series show the potential to block malaria transmission by inhibiting the growth of stage II/III and V gametocytes in vitro. Preliminary mechanistic insights also revealed hemozoin inhibition as a potential mode of action.
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Affiliation(s)
- Mziyanda Mbaba
- Department of Chemistry, Faculty of Science, University of Cape Town, Rondebosch, 7701, South Africa
| | - Taryn M Golding
- Department of Chemistry, Faculty of Science, University of Cape Town, Rondebosch, 7701, South Africa
| | - Reinner O Omondi
- Department of Chemistry, Faculty of Science, University of Cape Town, Rondebosch, 7701, South Africa
| | - Roxanne Mohunlal
- Department of Chemistry, Faculty of Science, University of Cape Town, Rondebosch, 7701, South Africa
| | - Timothy J Egan
- Department of Chemistry, Faculty of Science, University of Cape Town, Rondebosch, 7701, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, 0028, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, 0028, South Africa
| | - Gregory S Smith
- Department of Chemistry, Faculty of Science, University of Cape Town, Rondebosch, 7701, South Africa.
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2
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Chan XHS, Haeusler IL, Win YN, Pike J, Hanboonkunupakarn B, Hanafiah M, Lee SJ, Djimdé A, Fanello CI, Kiechel JR, Lacerda MVG, Ogutu B, Onyamboko MA, Siqueira AM, Ashley EA, Taylor WRJ, White NJ. The cardiovascular effects of amodiaquine and structurally related antimalarials: An individual patient data meta-analysis. PLoS Med 2021; 18:e1003766. [PMID: 34492005 PMCID: PMC8454971 DOI: 10.1371/journal.pmed.1003766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 09/21/2021] [Accepted: 08/11/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Amodiaquine is a 4-aminoquinoline antimalarial similar to chloroquine that is used extensively for the treatment and prevention of malaria. Data on the cardiovascular effects of amodiaquine are scarce, although transient effects on cardiac electrophysiology (electrocardiographic QT interval prolongation and sinus bradycardia) have been observed. We conducted an individual patient data meta-analysis to characterise the cardiovascular effects of amodiaquine and thereby support development of risk minimisation measures to improve the safety of this important antimalarial. METHODS AND FINDINGS Studies of amodiaquine for the treatment or prevention of malaria were identified from a systematic review. Heart rates and QT intervals with study-specific heart rate correction (QTcS) were compared within studies and individual patient data pooled for multivariable linear mixed effects regression. The meta-analysis included 2,681 patients from 4 randomised controlled trials evaluating artemisinin-based combination therapies (ACTs) containing amodiaquine (n = 725), lumefantrine (n = 499), piperaquine (n = 716), and pyronaridine (n = 566), as well as monotherapy with chloroquine (n = 175) for uncomplicated malaria. Amodiaquine prolonged QTcS (mean = 16.9 ms, 95% CI: 15.0 to 18.8) less than chloroquine (21.9 ms, 18.3 to 25.6, p = 0.0069) and piperaquine (19.2 ms, 15.8 to 20.5, p = 0.0495), but more than lumefantrine (5.6 ms, 2.9 to 8.2, p < 0.001) and pyronaridine (-1.2 ms, -3.6 to +1.3, p < 0.001). In individuals aged ≥12 years, amodiaquine reduced heart rate (mean reduction = 15.2 beats per minute [bpm], 95% CI: 13.4 to 17.0) more than piperaquine (10.5 bpm, 7.7 to 13.3, p = 0.0013), lumefantrine (9.3 bpm, 6.4 to 12.2, p < 0.001), pyronaridine (6.6 bpm, 4.0 to 9.3, p < 0.001), and chloroquine (5.9 bpm, 3.2 to 8.5, p < 0.001) and was associated with a higher risk of potentially symptomatic sinus bradycardia (≤50 bpm) than lumefantrine (risk difference: 14.8%, 95% CI: 5.4 to 24.3, p = 0.0021) and chloroquine (risk difference: 8.0%, 95% CI: 4.0 to 12.0, p < 0.001). The effect of amodiaquine on the heart rate of children aged <12 years compared with other antimalarials was not clinically significant. Study limitations include the unavailability of individual patient-level adverse event data for most included participants, but no serious complications were documented. CONCLUSIONS While caution is advised in the use of amodiaquine in patients aged ≥12 years with concomitant use of heart rate-reducing medications, serious cardiac conduction disorders, or risk factors for torsade de pointes, there have been no serious cardiovascular events reported after amodiaquine in widespread use over 7 decades. Amodiaquine and structurally related antimalarials in the World Health Organization (WHO)-recommended dose regimens alone or in ACTs are safe for the treatment and prevention of malaria.
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Affiliation(s)
- Xin Hui S. Chan
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail: (XHSC); (NJW)
| | - Ilsa L. Haeusler
- University College London Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Yan Naung Win
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Health and Diseases Control Unit, Naypyidaw, Myanmar
| | - James Pike
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Borimas Hanboonkunupakarn
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok Thailand
| | - Maryam Hanafiah
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sue J. Lee
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Abdoulaye Djimdé
- Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, Faculty of Pharmacy, University of Science Techniques and Technologies of Bamako, Bamako, Mali
| | - Caterina I. Fanello
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Marcus VG Lacerda
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, Brazil
- Instituto Leônidas e Maria Deane (FIOCRUZ-Amazonas), Fundacão Oswaldo Cruz, Manaus, Brazil
| | | | - Marie A. Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - André M. Siqueira
- Instituto Leônidas e Maria Deane (FIOCRUZ-Amazonas), Fundacão Oswaldo Cruz, Manaus, Brazil
- Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Elizabeth A. Ashley
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Walter RJ Taylor
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nicholas J. White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail: (XHSC); (NJW)
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3
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Sernoskie SC, Jee A, Uetrecht JP. The Emerging Role of the Innate Immune Response in Idiosyncratic Drug Reactions. Pharmacol Rev 2021; 73:861-896. [PMID: 34016669 DOI: 10.1124/pharmrev.120.000090] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Idiosyncratic drug reactions (IDRs) range from relatively common, mild reactions to rarer, potentially life-threatening adverse effects that pose significant risks to both human health and successful drug discovery. Most frequently, IDRs target the liver, skin, and blood or bone marrow. Clinical data indicate that most IDRs are mediated by an adaptive immune response against drug-modified proteins, formed when chemically reactive species of a drug bind to self-proteins, making them appear foreign to the immune system. Although much emphasis has been placed on characterizing the clinical presentation of IDRs and noting implicated drugs, limited research has focused on the mechanisms preceding the manifestations of these severe responses. Therefore, we propose that to address the knowledge gap between drug administration and onset of a severe IDR, more research is required to understand IDR-initiating mechanisms; namely, the role of the innate immune response. In this review, we outline the immune processes involved from neoantigen formation to the result of the formation of the immunologic synapse and suggest that this framework be applied to IDR research. Using four drugs associated with severe IDRs as examples (amoxicillin, amodiaquine, clozapine, and nevirapine), we also summarize clinical and animal model data that are supportive of an early innate immune response. Finally, we discuss how understanding the early steps in innate immune activation in the development of an adaptive IDR will be fundamental in risk assessment during drug development. SIGNIFICANCE STATEMENT: Although there is some understanding that certain adaptive immune mechanisms are involved in the development of idiosyncratic drug reactions, the early phase of these immune responses remains largely uncharacterized. The presented framework refocuses the investigation of IDR pathogenesis from severe clinical manifestations to the initiating innate immune mechanisms that, in contrast, may be quite mild or clinically silent. A comprehensive understanding of these early influences on IDR onset is crucial for accurate risk prediction, IDR prevention, and therapeutic intervention.
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Affiliation(s)
- Samantha Christine Sernoskie
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy (S.C.S., J.P.U.), and Department of Pharmacology and Toxicology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada (A.J., J.P.U.)
| | - Alison Jee
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy (S.C.S., J.P.U.), and Department of Pharmacology and Toxicology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada (A.J., J.P.U.)
| | - Jack Paul Uetrecht
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy (S.C.S., J.P.U.), and Department of Pharmacology and Toxicology, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada (A.J., J.P.U.)
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4
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Dziwornu GA, Coertzen D, Leshabane M, Korkor CM, Cloete CK, Njoroge M, Gibhard L, Lawrence N, Reader J, van der Watt M, Wittlin S, Birkholtz LM, Chibale K. Antimalarial Benzimidazole Derivatives Incorporating Phenolic Mannich Base Side Chains Inhibit Microtubule and Hemozoin Formation: Structure-Activity Relationship and In Vivo Oral Efficacy Studies. J Med Chem 2021; 64:5198-5215. [PMID: 33844521 DOI: 10.1021/acs.jmedchem.1c00354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A novel series of antimalarial benzimidazole derivatives incorporating phenolic Mannich base side chains at the C2 position, which possess dual asexual blood and sexual stage activities, is presented. Structure-activity relationship studies revealed that the 1-benzylbenzimidazole analogues possessed submicromolar asexual blood and sexual stage activities in contrast to the 1H-benzimidazole analogues, which were only active against asexual blood stage (ABS) parasites. Further, the former demonstrated microtubule inhibitory activity in ABS parasites but more significantly in stage II/III gametocytes. In addition to being bona fide inhibitors of hemozoin formation, the 1H-benzimidazole analogues also showed inhibitory effects on microtubules. In vivo efficacy studies in Plasmodium berghei-infected mice revealed that the frontrunner compound 41 exhibited high efficacy (98% reduction in parasitemia) when dosed orally at 4 × 50 mg/kg. Generally, the compounds were noncytotoxic to mammalian cells.
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Affiliation(s)
| | - Dina Coertzen
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Meta Leshabane
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Constance M Korkor
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Cleavon K Cloete
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Mathew Njoroge
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
| | - Liezl Gibhard
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
| | - Nina Lawrence
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory, Cape Town 7925, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4002, Switzerland.,University of Basel, Basel 4003, Switzerland
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa.,South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
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5
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Hosseini FS, Amanlou M. Anti-HCV and anti-malaria agent, potential candidates to repurpose for coronavirus infection: Virtual screening, molecular docking, and molecular dynamics simulation study. Life Sci 2020; 258:118205. [PMID: 32777300 PMCID: PMC7413873 DOI: 10.1016/j.lfs.2020.118205] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/24/2020] [Accepted: 08/01/2020] [Indexed: 01/25/2023]
Abstract
AIMS Coronavirus disease 2019 (COVID-19) has appeared in Wuhan, China but the fast transmission has led to its widespread prevalence in various countries, which has made it a global concern. Another concern is the lack of definitive treatment for this disease. The researchers tried different treatment options which are not specific. The current study aims to identify potential small molecule inhibitors against the main protease protein of SARS-CoV-2 by the computational approach. MAIN METHODS In this study, a virtual screening procedure employing docking of the two different datasets from the ZINC database, including 1615 FDA approved drugs and 4266 world approved drugs were used to identify new potential small molecule inhibitors for the newly released crystal structure of main protease protein of SARS-CoV-2. In the following to validate the docking result, molecular dynamics simulations were applied on selected ligands to identify the behavior and stability of them in the binding pocket of the main protease in 150 nanoseconds (ns). Furthermore, binding energy using the MMPBSA approach was also calculated. KEY FINDINGS The result indicates that simeprevir (Hepatitis C virus NS3/4A protease inhibitor) and pyronaridine (antimalarial agent) could fit well to the binding pocket of the main protease and because of some other beneficial features including broad-spectrum antiviral properties and ADME profile, they might be a promising drug candidate for repurposing to the treatment of COVID-19. SIGNIFICANCE Simeprevir and pyronaridine were selected by the combination of virtual screening and molecular dynamics simulation approaches as a potential candidate for treatment of COVID-19.
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Affiliation(s)
- Faezeh Sadat Hosseini
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Massoud Amanlou
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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6
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Lege S, Sorwat J, Yanez Heras JE, Zwiener C. Abiotic and biotic transformation of torasemide - Occurrence of degradation products in the aquatic environment. WATER RESEARCH 2020; 177:115753. [PMID: 32302808 DOI: 10.1016/j.watres.2020.115753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/14/2020] [Accepted: 03/21/2020] [Indexed: 06/11/2023]
Abstract
The pharmaceutical torasemide is an important loop diuretic and was 2017 one of the ten most prescribed drugs in Germany. Despite its detection in different compartments of the urban water cycle including drinking water, no studies were so far performed to elucidate its fate in the environment and the occurrence of transformation products (TPs). Therefore, we investigated the phototransformation, microbial degradation, transformation with human liver microsomes and anodic oxidation of torasemide to obtain good coverage of environmentally relevant degradation products. Overall sixteen products were identified, covering the following reaction mechanisms: aromatic and aliphatic hydroxylation, including further oxidation to carboxylic acids and quinone imines, amide cleavage, N-dealkylation, N-dearylation, and sulfonamide hydrolysis to sulfonic acids. Especially the formation of quinone imines could be of concern as they are highly reactive electrophiles. Torasemide itself was observed in all investigated wastewater treatment plant (WWTP) samples and wastewater-impacted surface waters. The maximum detected concentration was about 350 ng L-1. Only three of the sixteen transformation products were generally observed in at least one of the samples and the most frequently detected TPs were the human metabolites hydroxytorasemide (TP 364a) and carboxytorasemide (TP 378a). The complete removal of TP 364a during wastewater treatment was in agreement with the results of microbial degradation experiments. TP 364a was most likely transformed into TP 378a, which was microbially less degraded in lab experiments. Based on estimated concentrations, TP 378a could reach about 1 μg L-1 in the investigated wastewater matrices.
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Affiliation(s)
- Sascha Lege
- University of Tübingen, Environmental Analytical Chemistry at the Center for Applied Geoscience, Hölderlinstraße 12, 72074, Tübingen, Germany
| | - Julian Sorwat
- University of Tübingen, Environmental Analytical Chemistry at the Center for Applied Geoscience, Hölderlinstraße 12, 72074, Tübingen, Germany
| | - Jorge Eduardo Yanez Heras
- University of Tübingen, Environmental Analytical Chemistry at the Center for Applied Geoscience, Hölderlinstraße 12, 72074, Tübingen, Germany
| | - Christian Zwiener
- University of Tübingen, Environmental Analytical Chemistry at the Center for Applied Geoscience, Hölderlinstraße 12, 72074, Tübingen, Germany.
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7
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Lane TR, Massey C, Comer JE, Anantpadma M, Freundlich JS, Davey RA, Madrid PB, Ekins S. Repurposing the antimalarial pyronaridine tetraphosphate to protect against Ebola virus infection. PLoS Negl Trop Dis 2019; 13:e0007890. [PMID: 31751347 PMCID: PMC6894882 DOI: 10.1371/journal.pntd.0007890] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/05/2019] [Accepted: 10/29/2019] [Indexed: 12/28/2022] Open
Abstract
Recent outbreaks of the Ebola virus (EBOV) have focused attention on the dire need for antivirals to treat these patients. We identified pyronaridine tetraphosphate as a potential candidate as it is an approved drug in the European Union which is currently used in combination with artesunate as a treatment for malaria (EC50 between 420 nM—1.14 μM against EBOV in HeLa cells). Range-finding studies in mice directed us to a single 75 mg/kg i.p. dose 1 hr after infection which resulted in 100% survival and statistically significantly reduced viremia at study day 3 from a lethal challenge with mouse-adapted EBOV (maEBOV). Further, an EBOV window study suggested we could dose pyronaridine 2 or 24 hrs post-exposure to result in similar efficacy. Analysis of cytokine and chemokine panels suggests that pyronaridine may act as an immunomodulator during an EBOV infection. Our studies with pyronaridine clearly demonstrate potential utility for its repurposing as an antiviral against EBOV and merits further study in larger animal models with the added benefit of already being used as a treatment against malaria. To date there is no approved drug for Ebola Virus infection. Our approach has been to assess drugs that are already approved for other uses in various countries. Using computational models, we have previously identified three such drugs and demonstrated their activity against the Ebola virus in vitro. We now report on the in vitro absorption, metabolism, distribution, excretion and pharmacokinetic properties of one of these molecules, namely the antimalarial pyronaridine. We justify efficacy testing in the mouse model of ebola infection. We also demonstrate that a single dose of this drug is 100% effective against the virus. This study provides important preclinical evaluation of this already approved drug and justifies its selection for larger animal efficacy studies.
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Affiliation(s)
- Thomas R. Lane
- Collaborations Pharmaceuticals, Inc., Raleigh, NC, United States of America
| | - Christopher Massey
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Jason E. Comer
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States of America
- Institutional Office of Regulated Nonclinical Studies, University of Texas Medical Branch, Galveston, TX, United States of America
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Manu Anantpadma
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, United States of America
| | - Joel S. Freundlich
- Departments of Pharmacology, Physiology, and Neuroscience & Medicine, Center for Emerging and Reemerging Pathogens, Rutgers University–New Jersey Medical School, NJ, United States of America
| | - Robert A. Davey
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, United States of America
| | | | - Sean Ekins
- Collaborations Pharmaceuticals, Inc., Raleigh, NC, United States of America
- * E-mail:
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8
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Okombo J, Brunschwig C, Singh K, Dziwornu GA, Barnard L, Njoroge M, Wittlin S, Chibale K. Antimalarial Pyrido[1,2- a]benzimidazole Derivatives with Mannich Base Side Chains: Synthesis, Pharmacological Evaluation, and Reactive Metabolite Trapping Studies. ACS Infect Dis 2019; 5:372-384. [PMID: 30608648 DOI: 10.1021/acsinfecdis.8b00279] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A novel series of pyrido[1,2- a]benzimidazoles bearing Mannich base side chains and their metabolites were synthesized and evaluated for in vitro antiplasmodium activity, microsomal metabolic stability, reactive metabolite (RM) formation, and in vivo antimalarial efficacy in a mouse model. Oral administration of one of the derivatives at 4 × 50 mg/kg reduced parasitemia by 95% in Plasmodium berghei-infected mice, with a mean survival period of 16 days post-treatment. The in vivo efficacy of these derivatives is likely a consequence of their active metabolites, two of which showed potent in vitro antiplasmodium activity against chloroquine-sensitive and multidrug-resistant Plasmodium falciparum ( P. falciparum) strains. Rapid metabolism was observed for all the analogues with <40% of parent compound remaining after 30 min of incubation in liver microsomes. RM trapping studies detected glutathione adducts only in derivatives bearing 4-aminophenol moiety, with fragmentation signatures showing that this conjugation occurred on the phenyl ring of the Mannich base side chain. As with amodiaquine (AQ), interchanging the positions of the 4-hydroxyl and Mannich base side group or substituting the 4-hydroxyl with fluorine appeared to block bioactivation of the AQ-like derivatives though at the expense of antiplasmodium activity, which was significantly lowered.
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Affiliation(s)
- John Okombo
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Christel Brunschwig
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Kawaljit Singh
- South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | | | - Linley Barnard
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Mathew Njoroge
- Drug Discovery and Development Centre (H3D), Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4002, Switzerland
- University of Basel, Basel 4003, Switzerland
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
- South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
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9
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Abstract
Neutrophils are abundant in the circulation and are one of the immune system's first lines of defense against infection. There has been substantial work carried out investigating the role of neutrophils in malaria and it is clear that during infection neutrophils are activated and are capable of clearing malaria parasites by a number of mechanisms. This review focuses on neutrophil responses to human malarias, summarizing evidence which helps us understand where neutrophils are, what they are doing, how they interact with parasites as well as their potential role in vaccine mediated immunity. We also outline future research priorities for these, the most abundant of leukocytes.
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Affiliation(s)
- Elizabeth H Aitken
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Agersew Alemu
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Stephen J Rogerson
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
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Ramesh M, Bharatam PV. Formation of a Toxic Quinoneimine Metabolite from Diclofenac: A Quantum Chemical Study. Drug Metab Lett 2018; 13:64-76. [PMID: 30210009 DOI: 10.2174/1872312812666180913120736] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 08/27/2018] [Accepted: 08/27/2018] [Indexed: 01/26/2023]
Abstract
BACKGROUND Diclofenac is a non-steroidal antiinflammatory drug. It is predominantly metabolized by CYP2C9. 4'-hydroxydiclofenac and its quinoneimine are the metabolites of diclofenac. However, few numbers of serious cases of idiosyncratic hepatotoxicity due to diclofenac metabolism were reported. The formation of the quinoneimine metabolite was found to be responsible for this idiosyncratic toxicity. Quinoneimine is an over-oxidized metabolite of diclofenac. METHOD In this work, computational studies were conducted to detail the formation of a quinoneimine metabolite from diclofenac. Further, the idiosyncratic toxicity of quinoneimine due to its reactivity was also investigated by quantum chemical analysis. RESULTS & CONCLUSION The results demonstrate the possibility of formation of quinoneimine metabolite due to various factors that are involved in the metabolism of diclofenac. The present study may provide the structural in-sights during the drug development processes to avoid the metabolism directed idiosyncratic toxicity.
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Affiliation(s)
- Muthusamy Ramesh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar (Mohali)-160 062, India
| | - Prasad V Bharatam
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar (Mohali)-160 062, India
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11
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Limban C, Nuţă DC, Chiriţă C, Negreș S, Arsene AL, Goumenou M, Karakitsios SP, Tsatsakis AM, Sarigiannis DA. The use of structural alerts to avoid the toxicity of pharmaceuticals. Toxicol Rep 2018; 5:943-953. [PMID: 30258789 PMCID: PMC6151358 DOI: 10.1016/j.toxrep.2018.08.017] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/12/2018] [Accepted: 08/29/2018] [Indexed: 01/18/2023] Open
Abstract
In order to identify compounds with potential toxicity problems, particular attention is paid to structural alerts, which are high chemical reactivity molecular fragments or fragments that can be transformed via bioactivation by human enzymes into fragments with high chemical reactivity. The concept has been introduced in order to reduce the likelihood that future candidate substances as pharmaceuticals will have undesirable toxic effects. A significant proportion (∼78–86%) of drugs characterized by residual toxicity contain structural alerts; there is also evidence indicating the formation of active metabolites as a causal factor for the toxicity of 62–69% of these molecules. On the other hand, the pharmacological action of certain drugs depends on the formation of reactive metabolites. Detailed assessment of the potential for the formation of active metabolites is recommended to characterize a biologically active compound. Although many prescribed drugs frequently contain structural alerts and form reactive metabolites, the vast majority of these drugs are administered in low daily doses. Avoiding structural alerts has become almost a norm in new drug design. An in-depth review of the biochemical reactivity of these structural alerts for new drug candidates is critical from a safety point of view and is currently being monitored in the discovery of drugs. The chemical strategies applied to structural alerts in molecules to limit the toxicity are: partial replacement or full replacement of the structural alert; reduction of electronic density; introduction of a structural element of metabolic interest (metabolic switching); multiple approaches.
Therefore, chemical intervention strategies to eliminate bioactivation are often interactive processes; their success depends largely on a close working relationship between drug chemists, pharmacologists and researchers in metabolic science.
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Affiliation(s)
- Carmen Limban
- "Carol Davila" University of Medicine and Pharmacy, Department of Pharmaceutical Chemistry, Traian Vuia 6, Bucharest, 020956, Romania
| | - Diana C Nuţă
- "Carol Davila" University of Medicine and Pharmacy, Department of Pharmaceutical Chemistry, Traian Vuia 6, Bucharest, 020956, Romania
| | - Cornel Chiriţă
- "Carol Davila" University of Medicine and Pharmacy, Department of Pharmacology and Clinical Pharmacy, Traian Vuia 6, Bucharest, 020956, Romania
| | - Simona Negreș
- "Carol Davila" University of Medicine and Pharmacy, Department of Pharmacology and Clinical Pharmacy, Traian Vuia 6, Bucharest, 020956, Romania
| | - Andreea L Arsene
- "Carol Davila" University of Medicine and Pharmacy, Department of Pharmaceutical Microbiology, Traian Vuia 6, Bucharest, 020956, Romania
| | - Marina Goumenou
- Laboratory of Toxicology, Medical School, University of Crete, Voutes, Heraklion, 71409, Crete, Greece
| | - Spyros P Karakitsios
- Aristotle University of Thessaloniki, Department of Chemical Engineering, Environmental Engineering Laboratory, University Campus, Thessaloniki 54124, Greece.,HERACLES Research Center on the Exposome and Health, Center for Interdisciplinary Research and Innovation, Balkan Center, Bldg. B, 10th km Thessaloniki-Thermi Road, 57001, Greece
| | - Aristidis M Tsatsakis
- Laboratory of Toxicology, Medical School, University of Crete, Voutes, Heraklion, 71409, Crete, Greece
| | - Dimosthenis A Sarigiannis
- Aristotle University of Thessaloniki, Department of Chemical Engineering, Environmental Engineering Laboratory, University Campus, Thessaloniki 54124, Greece.,HERACLES Research Center on the Exposome and Health, Center for Interdisciplinary Research and Innovation, Balkan Center, Bldg. B, 10th km Thessaloniki-Thermi Road, 57001, Greece.,University School for Advanced Study (IUSS), Piazza della Vittoria 15, Pavia 27100, Italy
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12
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Zhang Y, den Braver-Sewradj SP, den Braver MW, Hiemstra S, Vermeulen NPE, van de Water B, Commandeur JNM, Vos JC. Glutathione S-Transferase P1 Protects Against Amodiaquine Quinoneimines-Induced Cytotoxicity but Does Not Prevent Activation of Endoplasmic Reticulum Stress in HepG2 Cells. Front Pharmacol 2018; 9:388. [PMID: 29720942 PMCID: PMC5915463 DOI: 10.3389/fphar.2018.00388] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 04/04/2018] [Indexed: 12/15/2022] Open
Abstract
Formation of the reactive amodiaquine quinoneimine (AQ-QI) and N-desethylamodiaquine quinoneimine (DEAQ-QI) plays an important role in the toxicity of the anti-malaria drug amodiaquine (AQ). Glutathione conjugation protects against AQ-induced toxicity and GSTP1 is able to conjugate its quinoneimine metabolites AQ-QI and DEA-QI with glutathione. In this study, HepG2 cells transiently transfected with the human GSTP1 construct were utilized to investigate the protective effect of GSTP1 in a cellular context. HepG2 cells were exposed to synthesized QIs, which bypasses the need for intracellular bioactivation of AQ or DEAQ. Exposure was accompanied by decreased cell viability, increased caspase 3 activity, and decreased intracellular GSH levels. Using high-content imaging-based BAC-GFP reporters, it was shown that AQ-QI and DEAQ-QI specifically activated the endoplasmic reticulum (ER) stress response. In contrast, oxidative stress, DNA damage, or inflammatory stress responses were not activated. Overexpression of GSTP1 resulted in a two-fold increase in GSH-conjugation of the QIs, attenuated QI-induced cytotoxicity especially under GSH-depletion condition, abolished QIs-induced apoptosis but did not significantly inhibit the activation of the ER stress response. In conclusion, these results indicate a protective role of GSTP1 by increasing enzymatic detoxification of AQ-QI and DEAQ-QI and suggest a second protective mechanism by interfering with ER stress induced apoptosis.
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Affiliation(s)
- Yongjie Zhang
- Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines and Systems, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.,Clinical Pharmacokinetics Research Laboratory, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Shalenie P den Braver-Sewradj
- Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines and Systems, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Michiel W den Braver
- Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines and Systems, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Steven Hiemstra
- Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research, Leiden University, Leiden, Netherlands
| | - Nico P E Vermeulen
- Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines and Systems, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Bob van de Water
- Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research, Leiden University, Leiden, Netherlands
| | - Jan N M Commandeur
- Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines and Systems, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - J C Vos
- Division of Molecular Toxicology, Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute for Molecules, Medicines and Systems, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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13
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Valverde EA, Romero AH, Acosta ME, Gamboa N, Henriques G, Rodrigues JR, Ciangherotti C, López SE. Synthesis, β-hematin inhibition studies and antimalarial evaluation of new dehydroxy isoquine derivatives against Plasmodium berghei: A promising antimalarial agent. Eur J Med Chem 2018; 148:498-506. [DOI: 10.1016/j.ejmech.2017.10.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/14/2017] [Accepted: 10/16/2017] [Indexed: 10/18/2022]
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14
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Boeltz S, Muñoz LE, Fuchs TA, Herrmann M. Neutrophil Extracellular Traps Open the Pandora's Box in Severe Malaria. Front Immunol 2017; 8:874. [PMID: 28804484 PMCID: PMC5532516 DOI: 10.3389/fimmu.2017.00874] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 07/10/2017] [Indexed: 01/15/2023] Open
Affiliation(s)
- Sebastian Boeltz
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Luis E Muñoz
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Tobias A Fuchs
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin Herrmann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany
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15
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Zhang Y, den Braver-Sewradj SP, Vos JC, Vermeulen NPE, Commandeur JNM. Human glutathione S-transferases- and NAD(P)H:quinone oxidoreductase 1-catalyzed inactivation of reactive quinoneimines of amodiaquine and N-desethylamodiaquine: Possible implications for susceptibility to amodiaquine-induced liver toxicity. Toxicol Lett 2017; 275:83-91. [PMID: 28478157 DOI: 10.1016/j.toxlet.2017.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 04/29/2017] [Accepted: 05/03/2017] [Indexed: 01/16/2023]
Abstract
Amodiaquine (AQ), an antimalarial drug, widely prescribed in endemic areas of Africa and Asia, is used in combination with artesunate as recommended by the WHO. However, due to its idiosyncratic hepatotoxicity and agranulocytosis, the therapeutic use has been discontinued in most countries. Oxidative bioactivation to protein-reactive quinonimines (QIs) by hepatic cytochrome P450s and myeloperoxidase (MPO) have been suggested to be important mechanisms underlying AQ idiosyncratic toxicity. However, the inactivation of the reactive QIs by detoxifying enzymes such as human glutathione S-transferases (GSTs) and NAD(P)H:quinone oxidoreducatase 1 (NQO1) has not been characterized yet. In the present study, the activities of 15 recombinant human GSTs and NQO1 in the inactivation of reactive QIs of AQ and its pharmacological active metabolite, N-desethylamodiaquine (DEAQ) were investigated. The results showed that GSTP1-1, GSTA4-4, GSTM4-4, GSTM2-2 and GSTA2-2 (activity in decreasing order) were active isoforms in catalyzing GSH conjugation of reactive QIs of AQ and DEAQ. Additionally, NQO1 was shown to inactivate these QIs by reduction. Simulation of the variability of cytosolic GST-activity based on the hepatic GST contents from 22 liver donors, showed a large variation in cytosolic inactivation of QIs by GSH, especially at a reduced GSH-concentration. In conclusion, the present study demonstrates that a low hepatic expression of the active GSTs and NQO1 may increase the susceptibility of patients to AQ idiosyncratic hepatotoxicity.
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Affiliation(s)
- Yongjie Zhang
- Division of Molecular Toxicology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Shalenie P den Braver-Sewradj
- Division of Molecular Toxicology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - J Chris Vos
- Division of Molecular Toxicology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Nico P E Vermeulen
- Division of Molecular Toxicology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Jan N M Commandeur
- Division of Molecular Toxicology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Department of Chemistry and Pharmaceutical Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
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16
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Abstract
A number of drugs have been withdrawn from the market or severely restricted in their use because of unexpected toxicities that become apparent only after the launch of new drug entities. Circumstantial evidence suggests that, in most cases, reactive metabolites are responsible for these unexpected toxicities. In this review, a general overview of the types of reactive metabolites and the consequences of their formation are presented. The current approaches to evaluate bioactivation potential of new compounds with particular emphasis on the advantages and limitation of these procedures will be discussed. Reasonable reasons for the excellent safety record of certain drugs susceptible to bioactivation will also be explored and should provide valuable guidance in the use of reactive-metabolite assessments when nominating drug candidates for development. This will, in turn, help us to design and bring safer drugs to the market.
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Affiliation(s)
- Sabry M Attia
- Department of Pharmacology and Toxicology; College of Pharmacy; King Saud University; Riyadh, Saudi Arabia.
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17
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Toler SM. Oxidative Stress Plays an Important Role in the Pathogenesis of Drug-Induced Retinopathy. Exp Biol Med (Maywood) 2016; 229:607-15. [PMID: 15229354 DOI: 10.1177/153537020422900704] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Several pharmaceutical agents have been associated with rare but serious retinopathies, some resulting in blindness. Little is known of the mechanism(s) that produce these injuries. Mechanisms proposed thus far have not been embraced by the medical and scientific communities. However, preclinical and clinical data indicate that oxidative stress may contribute substantially to iatrogenic retinal disease. Retinal oxidative stress may be precipitated by the interaction of putative retinal toxins with the ocular redox system. The retina, replete with cytochromes P450 and myeloperoxidase, may serve to activate xenobiotics to oxidants, resulting in ocular injury. These activated agents may directly form retinal adducts or may diminish ocular reduced glutathione concentrations. Data are reviewed that suggest that indomethacin, tamoxifen, thioridazine, and chloroquine all produce retinopathies via a common mechanism—they produce ocular oxidative stress.
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Affiliation(s)
- Steven M Toler
- Clinical Safety and Risk Management, Pfizer Inc., Pfizer Global Research and Development, 50 Pequot Avenue, New London, CT 06320, USA.
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18
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Zhang Y, Vermeulen NPE, Commandeur JNM. Characterization of human cytochrome P450 mediated bioactivation of amodiaquine and its major metabolite N-desethylamodiaquine. Br J Clin Pharmacol 2016; 83:572-583. [PMID: 27718269 DOI: 10.1111/bcp.13148] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/12/2016] [Accepted: 10/02/2016] [Indexed: 01/12/2023] Open
Abstract
AIMS Oxidative bioactivation of amodiaquine (AQ) by cytochrome P450s to a reactive quinoneimine is considered as an important mechanism underlying its idiosyncratic hepatotoxicity. However, because internal exposure to its major metabolite N-desethylamodiaquine (DEAQ) is up to 240-fold higher than AQ, bioactivation of DEAQ might significantly contribute to covalent binding. The aim of the present study was to compare the kinetics of bioactivation of AQ and DEAQ by human liver microsomes (HLM) and to characterize the CYPs involved in bioactivation of AQ and DEAQ. METHODS Glutathione was used to trap reactive metabolites formed in incubations of AQ and DEAQ with HLM and recombinant human cytochrome P450s (hCYPs). Kinetics of bioactivation of AQ and DEAQ in HLM and involvement of hCYPs were characterized by measuring corresponding glutathione conjugates (AQ-SG and DEAQ-SG) using a high-performance liquid chromatography method. RESULTS Bioactivation of AQ and DEAQ in HLM both exhibited Michaelis-Menten kinetics. For AQ bioactivation, enzyme kinetical parameters were Km , 11.5 ± 2.0 μmol l-1 , Vmax , 59.2 ± 3.2 pmol min-1 mg-1 and CLint , 5.15 μl min-1 mg-1 . For DEAQ, parameters for bioactivation were Km , 6.1 ± 1.3 μmol l-1 , Vmax , 5.5 ± 0.4 pmol min-1 mg-1 and CLint 0.90 μl min-1 mg-1 . Recombinant hCYPs and inhibition studies with HLM showed involvement of CYP3A4, CYP2C8, CYP2C9 and CYP2D6 in bioactivation. CONCLUSIONS The major metabolite DEAQ is likely to be quantitatively more important than AQ with respect to hepatic exposure to reactive metabolites in vivo. High expression of CYP3A4, CYP2C8, CYP2C9, and CYP2D6 may be risk factors for hepatotoxicity caused by AQ-therapy.
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Affiliation(s)
- Yongjie Zhang
- Division of Molecular Toxicology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Nico P E Vermeulen
- Division of Molecular Toxicology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Jan N M Commandeur
- Division of Molecular Toxicology, Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Department of Chemistry and Pharmaceutical Sciences, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
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19
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Tailor A, Waddington JC, Meng X, Park BK. Mass Spectrometric and Functional Aspects of Drug–Protein Conjugation. Chem Res Toxicol 2016; 29:1912-1935. [DOI: 10.1021/acs.chemrestox.6b00147] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Arun Tailor
- MRC Center
for Drug Safety
Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, United Kingdom
| | - James C. Waddington
- MRC Center
for Drug Safety
Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, United Kingdom
| | - Xiaoli Meng
- MRC Center
for Drug Safety
Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, United Kingdom
| | - B. Kevin Park
- MRC Center
for Drug Safety
Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, United Kingdom
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20
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Romero AH, Acosta ME, Gamboa N, Charris JE, Salazar J, López SE. Synthesis, β-hematin inhibition studies and antimalarial evaluation of dehydroxy isotebuquine derivatives against Plasmodium berghei. Bioorg Med Chem 2015; 23:4755-4762. [DOI: 10.1016/j.bmc.2015.05.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 05/15/2015] [Accepted: 05/24/2015] [Indexed: 11/29/2022]
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Ongarora DSB, Strydom N, Wicht K, Njoroge M, Wiesner L, Egan TJ, Wittlin S, Jurva U, Masimirembwa CM, Chibale K. Antimalarial benzoheterocyclic 4-aminoquinolines: Structure-activity relationship, in vivo evaluation, mechanistic and bioactivation studies. Bioorg Med Chem 2015; 23:5419-32. [PMID: 26264839 DOI: 10.1016/j.bmc.2015.07.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/15/2015] [Accepted: 07/25/2015] [Indexed: 10/23/2022]
Abstract
A novel class of benzoheterocyclic analogues of amodiaquine designed to avoid toxic reactive metabolite formation was synthesized and evaluated for antiplasmodial activity against K1 (multidrug resistant) and NF54 (sensitive) strains of the malaria parasite Plasmodium falciparum. Structure-activity relationship studies led to the identification of highly promising analogues, the most potent of which had IC50s in the nanomolar range against both strains. The compounds further demonstrated good in vitro microsomal metabolic stability while those subjected to in vivo pharmacokinetic studies had desirable pharmacokinetic profiles. In vivo antimalarial efficacy in Plasmodium berghei infected mice was evaluated for four compounds, all of which showed good activity following oral administration. In particular, compound 19 completely cured treated mice at a low multiple dose of 4×10mg/kg. Mechanistic and bioactivation studies suggest hemozoin formation inhibition and a low likelihood of forming quinone-imine reactive metabolites, respectively.
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Affiliation(s)
- Dennis S B Ongarora
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa; South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa; Department of Pharmaceutical Chemistry, University of Nairobi, Nairobi, Kenya
| | - Natasha Strydom
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kathryn Wicht
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Mathew Njoroge
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa; South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Observatory 7925, South Africa
| | - Timothy J Egan
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland; University of Basel, Socinstrasse 57, 4002 Basel, Switzerland
| | | | | | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa; Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa; South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa.
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22
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JPC-2997, a new aminomethylphenol with high in vitro and in vivo antimalarial activities against blood stages of Plasmodium. Antimicrob Agents Chemother 2014; 59:170-7. [PMID: 25331702 DOI: 10.1128/aac.03762-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
4-(tert-Butyl)-2-((tert-butylamino)methyl)-6-(6-(trifluoromethyl)pyridin-3-yl)-phenol (JPC-2997) is a new aminomethylphenol compound that is highly active in vitro against the chloroquine-sensitive D6, the chloroquine-resistant W2, and the multidrug-resistant TM90-C2B Plasmodium falciparum lines, with 50% inhibitory concentrations (IC50s) ranging from 7 nM to 34 nM. JPC-2997 is >2,500 times less cytotoxic (IC50s > 35 μM) to human (HepG2 and HEK293) and rodent (BHK) cell lines than the D6 parasite line. In comparison to the chemically related WR-194,965, a drug that had advanced to clinical studies, JPC-2997 was 2-fold more active in vitro against P. falciparum lines and 3-fold less cytotoxic. The compound possesses potent in vivo suppression activity against Plasmodium berghei, with a 50% effective dose (ED50) of 0.5 mg/kg of body weight/day following oral dosing in the Peters 4-day test. The radical curative dose of JPC-2997 was remarkably low, at a total dose of 24 mg/kg, using the modified Thompson test. JPC-2997 was effective in curing three Aotus monkeys infected with a chloroquine- and pyrimethamine-resistant strain of Plasmodium vivax at a dose of 20 mg/kg daily for 3 days. At the doses administered, JPC-2997 appeared to be well tolerated in mice and monkeys. Preliminary studies of JPC-2997 in mice show linear pharmacokinetics over the range 2.5 to 40 mg/kg, a low clearance of 0.22 liters/h/kg, a volume of distribution of 15.6 liters/kg, and an elimination half-life of 49.8 h. The high in vivo potency data and lengthy elimination half-life of JPC-2997 suggest that it is worthy of further preclinical assessment as a partner drug.
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23
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Njoroge M, Njuguna NM, Mutai P, Ongarora DSB, Smith PW, Chibale K. Recent approaches to chemical discovery and development against malaria and the neglected tropical diseases human African trypanosomiasis and schistosomiasis. Chem Rev 2014; 114:11138-63. [PMID: 25014712 DOI: 10.1021/cr500098f] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | | | | | - Paul W Smith
- Novartis Institute for Tropical Diseases , Singapore 138670, Singapore
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24
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Bukirwa H, Unnikrishnan B, Kramer CV, Sinclair D, Nair S, Tharyan P. Artesunate plus pyronaridine for treating uncomplicated Plasmodium falciparum malaria. Cochrane Database Syst Rev 2014:CD006404. [PMID: 24596021 PMCID: PMC4448218 DOI: 10.1002/14651858.cd006404.pub2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND The World Health Organization (WHO) recommends that people with uncomplicated Plasmodium falciparum malaria are treated using Artemisinin-based Combination Therapy (ACT). ACT combines three-days of a short-acting artemisinin derivative with a longer-acting antimalarial which has a different mode of action. Pyronaridine has been reported as an effective antimalarial over two decades of use in parts of Asia, and is currently being evaluated as a partner drug for artesunate. OBJECTIVES To evaluate the efficacy and safety of artesunate-pyronaridine compared to alternative ACTs for treating people with uncomplicated P. falciparum malaria. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library; MEDLINE; EMBASE; LILACS; ClinicalTrials.gov; the metaRegister of Controlled Trials (mRCT); and the WHO International Clinical Trials Search Portal up to 16 January 2014. We searched reference lists and conference abstracts, and contacted experts for information about ongoing and unpublished trials. SELECTION CRITERIA Randomized controlled trials of artesunate-pyronaridine versus other ACTs in adults and children with uncomplicated P. falciparum malaria.For the safety analysis, we also included adverse events data from trials comparing any treatment regimen containing pyronaridine with regimens not containing pyronaridine. DATA COLLECTION AND ANALYSIS Two authors independently assessed trial eligibility and risk of bias, and extracted data. We combined dichotomous data using risk ratios (RR) and continuous data using mean differences (MD), and presented all results with a 95% confidence interval (CI). We used the GRADE approach to assess the quality of evidence. MAIN RESULTS We included six randomized controlled trials enrolling 3718 children and adults. Artesunate-pyronaridine versus artemether-lumefantrineIn two multicentre trials, enrolling mainly older children and adults from west and south-central Africa, both artesunate-pyronaridine and artemether-lumefantrine had fewer than 5% PCR adjusted treatment failures during 42 days of follow-up, with no differences between groups (two trials, 1472 participants, low quality evidence). There were fewer new infections during the first 28 days in those given artesunate-pyronaridine (PCR-unadjusted treatment failure: RR 0.60, 95% CI 0.40 to 0.90, two trials, 1720 participants, moderate quality evidence), but no difference was detected over the whole 42 day follow-up (two trials, 1691 participants, moderate quality evidence). Artesunate-pyronaridine versus artesunate plus mefloquineIn one multicentre trial, enrolling mainly older children and adults from South East Asia, both artesunate-pyronaridine and artesunate plus mefloquine had fewer than 5% PCR adjusted treatment failures during 28 days follow-up (one trial, 1187 participants, moderate quality evidence). PCR-adjusted treatment failures were 6% by day 42 for these treated with artesunate-pyronaridine, and 4% for those with artesunate-mefloquine (RR 1.64, 95% CI 0.89 to 3.00, one trial, 1116 participants, low quality evidence). Again, there were fewer new infections during the first 28 days in those given artesunate-pyronaridine (PCR-unadjusted treatment failure: RR 0.35, 95% CI 0.17 to 0.73, one trial, 1720 participants, moderate quality evidence), but no differences were detected over the whole 42 days (one trial, 1146 participants, low quality evidence). Adverse effectsSerious adverse events were uncommon in these trials, with no difference detected between artesunate-pyronaridine and comparator ACTs. The analysis of liver function tests showed biochemical elevation were four times more frequent with artesunate-pyronaridine than with the other antimalarials (RR 4.17, 95% CI 1.38 to 12.62, four trials, 3523 participants, moderate quality evidence). AUTHORS' CONCLUSIONS Artesunate-pyronaridine performed well in these trials compared to artemether-lumefantrine and artesunate plus mefloquine, with PCR-adjusted treatment failure at day 28 below the 5% standard set by the WHO. Further efficacy and safety studies in African and Asian children are required to clarify whether this combination is an option for first-line treatment.
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Affiliation(s)
| | - B Unnikrishnan
- Department of Community Medicine, Kasturba Medical CollegeMangalore, India
| | - Christine V Kramer
- Cochrane Infectious Diseases Group, Liverpool School of Tropical MedicineLiverpool, UK
| | - David Sinclair
- Department of Clinical Sciences, Liverpool School of Tropical MedicineLiverpool, UK
| | - Suma Nair
- Community Medicine, Kasturba Medical CollegeManipal, India
| | - Prathap Tharyan
- South Asian Cochrane Network & Centre, Prof. BV Moses Centre for Evidence-Informed Health Care and Health Policy, Christian Medical CollegeVellore, India
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Croft SL, Duparc S, Arbe-Barnes SJ, Craft JC, Shin CS, Fleckenstein L, Borghini-Fuhrer I, Rim HJ. Review of pyronaridine anti-malarial properties and product characteristics. Malar J 2012; 11:270. [PMID: 22877082 PMCID: PMC3483207 DOI: 10.1186/1475-2875-11-270] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 07/04/2012] [Indexed: 11/10/2022] Open
Abstract
Pyronaridine was synthesized in 1970 at the Institute of Chinese Parasitic Disease and has been used in China for over 30 years for the treatment of malaria. Pyronaridine has high potency against Plasmodium falciparum, including chloroquine-resistant strains. Studies in various animal models have shown pyronaridine to be effective against strains resistant to other anti-malarials, including chloroquine. Resistance to pyronaridine appears to emerge slowly and is further retarded when pyronaridine is used in combination with other anti-malarials, in particular, artesunate. Pyronaridine toxicity is generally less than that of chloroquine, though evidence of embryotoxicity in rodents suggests use with caution in pregnancy. Clinical pharmacokinetic data for pyronaridine indicates an elimination T1/2 of 13.2 and 9.6 days, respectively, in adults and children with acute uncomplicated falciparum and vivax malaria in artemisinin-combination therapy. Clinical data for mono or combined pyronaridine therapy show excellent anti-malarial effects against P. falciparum and studies of combination therapy also show promise against Plasmodium vivax. Pyronaridine has been developed as a fixed dose combination therapy, in a 3:1 ratio, with artesunate for the treatment of acute uncomplicated P. falciparum malaria and blood stage P. vivax malaria with the name of Pyramax® and has received Positive Opinion by European Medicines Agency under the Article 58 procedure.
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Affiliation(s)
- Simon L Croft
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
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Piedade R, Gil JP. The pharmacogenetics of antimalaria artemisinin combination therapy. Expert Opin Drug Metab Toxicol 2011; 7:1185-200. [PMID: 21899476 DOI: 10.1517/17425255.2011.608660] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Plasmodium falciparum malaria is one of the world's most lethal infectious diseases, commanding millions of drug administrations per year. The pharmacogenetics of these drugs is poorly known, although its application can be pivotal for the optimized management of this disease. AREAS COVERED The main components of artemisinin combination therapy (ACT), the worldwide main antimalarial strategy, are metabolized by the polymorphic CYP3A4 (mefloquine, artemether, lumefantrine), CYP2C8 (amodiaquine), CYP2A6 (artesunate) and CYP1A1/2 (amodiaquine/desethylamodiaquine), with dihydroartemisinin being acted by Phase II UDP-glucuronosyltransferases. The worldwide adoption of ACT is leading to a large number of antimalarial treatments. Simultaneously, the feared development of parasite drug resistance might drive dosing increases. In these scenarios of increased drug exposure, pharmacogenetics can be a key tool supporting evidence-based medicine aiming for the longest possible useful lifespan of this important chemotherapy. EXPERT OPINION Translation in this moment is not operationally possible at an individual level, but large population studies are achievable for: i) the development of robust pharmacogenetics markers; and ii) the parallel development of a pharmacogenetic cartography of malaria settings. Advances in the understanding of antimalarial pharmacogenetics are urgent in order to protect the exposed populations, enhance the effectiveness of ACT and, consequently, contributing for the long aimed elimination of the disease.
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Affiliation(s)
- Rita Piedade
- Karolinska Institute, Division of Pharmacogenetics, Department of Physiology and Pharmacology, Stockholm, Sweden
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Le Fur N, Hochart G, Larchanché PE, Melnyk P. Buchwald reaction as the key step for the synthesis of metabolically more stable analogs of amodiaquine. Eur J Med Chem 2011; 46:3052-7. [DOI: 10.1016/j.ejmech.2011.04.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/14/2011] [Accepted: 04/15/2011] [Indexed: 11/30/2022]
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Nakayama S, Takakusa H, Watanabe A, Miyaji Y, Suzuki W, Sugiyama D, Shiosakai K, Honda K, Okudaira N, Izumi T, Okazaki O. Combination of GSH Trapping and Time-Dependent Inhibition Assays as a Predictive Method of Drugs Generating Highly Reactive Metabolites. Drug Metab Dispos 2011; 39:1247-54. [DOI: 10.1124/dmd.111.039180] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Eastman RT, Fidock DA. Artemisinin-based combination therapies: a vital tool in efforts to eliminate malaria. Nat Rev Microbiol 2009; 7:864-74. [PMID: 19881520 DOI: 10.1038/nrmicro2239] [Citation(s) in RCA: 358] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Plasmodium falciparum resistance to chloroquine and sulphadoxine-pyrimethamine has led to the recent adoption of artemisinin-based combination therapies (ACTs) as the first line of treatment against malaria. ACTs comprise semisynthetic artemisinin derivatives paired with distinct chemical classes of longer acting drugs. These artemisinins are exceptionally potent against the pathogenic asexual blood stages of Plasmodium parasites and also act on the transmissible sexual stages. These combinations increase the rates of clinical and parasitological cures and decrease the selection pressure for the emergence of antimalarial resistance. This Review article discusses our current knowledge about the mode of action of ACTs, their pharmacological properties and the proposed mechanisms of drug resistance.
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Affiliation(s)
- Richard T Eastman
- Department of Microbiology & Immunology, Columbia University College of Physicians and Surgeons, Hammer Health Sciences Center, Room 1502, 701 West 168th Street, New York 10032, New York, USA.
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Păunescu E, Susplugas S, Boll E, Varga R, Mouray E, Grosu I, Grellier P, Melnyk P. Replacement of the 4'-hydroxy group of amodiaquine and amopyroquine by aromatic and aliphatic substituents: synthesis and antimalarial activity. ChemMedChem 2009; 4:549-61. [PMID: 19212949 DOI: 10.1002/cmdc.200800318] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The prophylactic administration of amodiaquine (AQ), a 4-aminoquinoline antimalarial drug, has been associated with side effects such as agranulocytosis and liver damage. The toxicity of this drug is mediated by amodiaquine quinone-imine, an electrophilic metabolite. Replacement of the 4'-hydroxy function of AQ with various alkyl, aryl, or heteroaryl substituents would provide analogues that avoid metabolism to potentially toxic derivatives. Following a multistep procedure, 33 compounds containing hydrophobic groups at the 4'-position were synthesized using Csp(2)-Csp(2) and Csp(2)-Csp(3) Suzuki-Miyaura cross-coupling reactions as the key step. The new derivatives were found to be active against both chloroquine (CQ)-sensitive and CQ-resistant strains of P. falciparum, with IC(50) values in the range of 7-200 nM. Alkyl analogues are more efficient than aryl or heteroaryl derivatives. All compounds were also assessed for their cytotoxicity and ability to inhibit beta-hematin formation in vitro. A detailed investigation of the structure-activity relationships for these new compounds was carried out; the 4'-methyl compound showed interesting in vivo antimalarial activity.
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Ismail FMD, Drew MGB, Navaratnam S, Bisby RH. A pulse radiolysis study of free radicals formed by one-electron oxidation of the antimalarial drug pyronaridine. RESEARCH ON CHEMICAL INTERMEDIATES 2009. [DOI: 10.1007/s11164-009-0051-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ntale M, Obua C, Mukonzo J, Mahindi M, Gustafsson LL, Beck O, Ogwal-Okeng JW. Field-adapted sampling of whole blood to determine the levels of amodiaquine and its metabolite in children with uncomplicated malaria treated with amodiaquine plus artesunate combination. Malar J 2009; 8:52. [PMID: 19331684 PMCID: PMC2678144 DOI: 10.1186/1475-2875-8-52] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Accepted: 03/30/2009] [Indexed: 01/19/2023] Open
Abstract
Background Artemisinin combination therapy (ACT) has been widely adopted as first-line treatment for uncomplicated falciparum malaria. In Uganda, amodiaquine plus artesunate (AQ+AS), is the alternative first-line regimen to Coartem® (artemether + lumefantrine) for the treatment of uncomplicated falciparum malaria. Currently, there are few field-adapted analytical techniques for monitoring amodiaquine utilization in patients. This study evaluates the field applicability of a new method to determine amodiaquine and its metabolite concentrations in whole blood dried on filter paper. Methods Twelve patients aged between 1.5 to 8 years with uncomplicated malaria received three standard oral doses of AQ+AS. Filter paper blood samples were collected before drug intake and at six different time points over 28 days period. A new field-adapted sampling procedure and liquid chromatographic method was used for quantitative determination of amodiaquine and its metabolite in whole blood. Results The sampling procedure was successively applied in the field. Amodiaquine could be quantified for at least three days and the metabolite up to 28 days. All parasites in all the 12 patients cleared within the first three days of treatment and no adverse drug effects were observed. Conclusion The methodology is suitable for field studies. The possibility to determine the concentration of the active metabolite of amodiaquine up to 28 days suggested that the method is sensitive enough to monitor amodiaquine utilization in patients. Amodiaquine plus artesunate seems effective for treatment of falciparum malaria.
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Affiliation(s)
- Muhammad Ntale
- Department of Pharmacology and Therapeutics, Makerere University, Kampala, Uganda.
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Daneshfar A, Khezeli T, Manafi MH. Determination of anti-malaria agent chloroquine using single drop liquid-liquid-liquid microextraction. J Sep Sci 2009; 32:511-6. [DOI: 10.1002/jssc.200800483] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Wen B, Fitch WL. Screening and characterization of reactive metabolites using glutathione ethyl ester in combination with Q-trap mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2009; 44:90-100. [PMID: 18720456 DOI: 10.1002/jms.1475] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The present study describes a new analytical approach for the detection and characterization of chemically reactive metabolites using glutathione ethyl ester (GSH-EE) as the trapping agent in combination with hybrid triple quadrupole linear ion trap mass spectrometry. Polarity switching was applied between a negative precursor ion (PI) survey scan and the positive enhanced product ion (EPI) scan. The negative PI scan step was carried out monitoring the anion at m/z 300, corresponding to deprotonated gamma-glutamyl-dehydroalanyl-glycine ethyl ester originating from the GSH-EE moiety. Samples resulting from incubations in the presence of GSH-EE were cleaned and concentrated by solid-phase extraction, followed by the PI-EPI analysis. Unambiguous identification of GSH-EE-trapped reactive metabolites was greatly facilitated by the unique survey scan of the anion at m/z 300, which achieved less background interference, in particular, from endogenous glutathione adducts present in human liver microsomes. Further structural characterization was achieved by analyzing positive MS(2) spectra that featured rich fragments without mass cutoff and were acquired in the same liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The effectiveness and reliability of this approach was evaluated using a number of model compounds in human liver microsomal incubations, including acetaminophen, amodiaquine, carbamazepine, 4-ethylphenol, imipramine and ticlopidine. In addition, iminoquinone reactive metabolites of mianserin were trapped and characterized for the first time using this method. Compared to neutral loss (NL) scanning assays using GSH as the trapping agent, the results have demonstrated superior selectivity, sensitivity, and reliability of this current approach.
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Affiliation(s)
- Bo Wen
- Department of Drug Metabolism and Pharmacokinetics, Roche Palo Alto, Palo Alto, CA 94304, USA.
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Johansson T, Jurva U, Grönberg G, Weidolf L, Masimirembwa C. Novel Metabolites of Amodiaquine Formed by CYP1A1 and CYP1B1: Structure Elucidation Using Electrochemistry, Mass Spectrometry, and NMR. Drug Metab Dispos 2008; 37:571-9. [DOI: 10.1124/dmd.108.025171] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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The roles of drug metabolism in the pathogenesis of T-cell-mediated drug hypersensitivity. Curr Opin Allergy Clin Immunol 2008; 8:299-307. [DOI: 10.1097/aci.0b013e3283079c64] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Schlitzer M. Antimalarial drugs - what is in use and what is in the pipeline. Arch Pharm (Weinheim) 2008; 341:149-63. [PMID: 18297679 DOI: 10.1002/ardp.200700184] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Malaria continues to be a potentially fatal threat to almost half of the world's population. In light of this threat, the armory to fight this disease is rather limited. Resistance against the most common and affordable antimalarials is widespread. Only few new drugs are in clinical development, most of them belong to long used classes of antimalarial drugs. This review will concisely cover the drugs which are currently in use, and describe the drug candidates which are in clinical evaluation.
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Affiliation(s)
- Martin Schlitzer
- Philipps-Universität, Institut für Pharmazeutische Chemie, Marburg, Germany.
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Jurva U, Holmén A, Grönberg G, Masimirembwa C, Weidolf L. Electrochemical Generation of Electrophilic Drug Metabolites: Characterization of Amodiaquine Quinoneimine and Cysteinyl Conjugates by MS, IR, and NMR. Chem Res Toxicol 2008; 21:928-35. [DOI: 10.1021/tx700400c] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ulrik Jurva
- AstraZeneca R&D Mölndal, S-431 83 Mölndal, Sweden
| | | | | | | | - Lars Weidolf
- AstraZeneca R&D Mölndal, S-431 83 Mölndal, Sweden
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Delarue-Cochin S, Paunescu E, Maes L, Mouray E, Sergheraert C, Grellier P, Melnyk P. Synthesis and antimalarial activity of new analogues of amodiaquine. Eur J Med Chem 2008; 43:252-60. [PMID: 17485145 DOI: 10.1016/j.ejmech.2007.03.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 03/02/2007] [Accepted: 03/08/2007] [Indexed: 11/28/2022]
Abstract
In order to determine the real significance of the 4'-phenolic group in the antimalarial activity and/or cytotoxicity of amodiaquine (AQ), analogues for which this functionality was shifted or modified were synthesized. Good in vitro antimalarial activity was obtained for compounds unable to form intramolecular hydrogen bond. Among the compounds synthesized, new amino derivative 5 displayed the greatest selectivity index towards the most CQ-resistant strain tested and was active in mice infected by Plasmodium berghei.
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Affiliation(s)
- Sandrine Delarue-Cochin
- UMR CNRS 8525, Université de Lille II, Institut Pasteur de Lille 1 rue du Professeur Calmette, B.P. 447, 59021 Lille cedex, France
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Abstract
Widespread parasitic resistance has led to an urgent need for the development and implementation of new drugs for the treatment of Plasmodium falciparum malaria. Artemisinin and its derivatives are becoming increasingly important, used preferably in combination with a second antimalarial agent to increase the efficacy and slow the development of resistance. However, cost, production and pharmacological issues associated with artemisinin derivatives and potential partner drugs are hindering the implementation of combination therapies. This article reviews the molecular basis of the action of, and resistance to, different antimalarials and examines the prospects for the next generation of drugs to combat this potentially lethal human pathogen.
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Affiliation(s)
- Leann Tilley
- Department of Biochemistry, La Trobe University, Melbourne, Victoria, Australia.
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Lohmann W, Karst U. Generation and Identification of Reactive Metabolites by Electrochemistry and Immobilized Enzymes Coupled On-Line to Liquid Chromatography/Mass Spectrometry. Anal Chem 2007; 79:6831-9. [PMID: 17685550 DOI: 10.1021/ac071100r] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The detection of reactive metabolites using conventional in vivo and in vitro techniques is hampered because the intermediately formed reactive species are prone to covalent binding to cellular macromolecules. Therefore, the application of improved methods is required. The on-line coupling of an electrochemical reactor and horseradish peroxidase immobilized on magnetic microparticles with liquid chromatography/mass spectrometry (EC/LC/MS or HRP/LC/MS) allows the direct detection of reactive metabolites of the model compounds amodiaquine, amsacrine, and mitoxantrone, which are all known for readily binding to cellular macromolecules after metabolization by cytochrome P450. EC/LC/MS and HRP/LC/MS experiments were compared to rat liver microsome incubations and proved to be valuable complementary methods since reactive quinone, quinone imine, and quinone diimine species could be detected directly and not only after trapping with glutathione. Furthermore, N-dealkylation and N-oxidation of amodiaquine were successfully simulated by electrochemical oxidation reactions, as well as the formation of an aldehyde. Therefore, EC/LC/MS and HRP/LC/MS are promising tools for the identification of both reactive and stable metabolites in drug development.
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Affiliation(s)
- Wiebke Lohmann
- Westfälische Wilhelms-Universität Münster, Institut für Anorganische und Analytische Chemie, Corrensstrasse 30, 48149, Münster, Germany
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Schlitzer M. Malaria Chemotherapeutics Part I: History of Antimalarial Drug Development, Currently Used Therapeutics, and Drugs in Clinical Development. ChemMedChem 2007; 2:944-86. [PMID: 17530725 DOI: 10.1002/cmdc.200600240] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Since ancient times, humankind has had to struggle against the persistent onslaught of pathogenic microorganisms. Nowadays, malaria is still the most important infectious disease worldwide. Considerable success in gaining control over malaria was achieved in the 1950s and 60s through landscaping measures, vector control with the insecticide DDT, and the widespread administration of chloroquine, the most important antimalarial agent ever. In the late 1960s, the final victory over malaria was believed to be within reach. However, the parasites could not be eradicated because they developed resistance against the most widely used and affordable drugs of that time. Today, cases of malaria infections are on the rise and have reached record numbers. This review gives a short description of the malaria disease, briefly addresses the history of antimalarial drug development, and focuses on drugs currently available for malaria therapy. The present knowledge regarding their mode of action and the mechanisms of resistance are explained, as are the attempts made by numerous research groups to overcome the resistance problem within classes of existing drugs and in some novel classes. Finally, this review covers all classes of antimalarials for which at least one drug candidate is in clinical development. Antimalarial agents that are solely in early development stages will be addressed in a separate review.
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Affiliation(s)
- Martin Schlitzer
- Institut für Pharmazeutische Chemie, Philipps-Universität Marburg, Marbacher Weg 6, 35032 Marburg, Germany.
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Gedela S, Medicherla NR. Chromatographic Techniques for the Separation of Peptides: Application to Proteomics. Chromatographia 2007. [DOI: 10.1365/s10337-007-0215-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Miroshnikova OV, Hudson TH, Gerena L, Kyle DE, Lin AJ. Synthesis and antimalarial activity of new isotebuquine analogues. J Med Chem 2007; 50:889-96. [PMID: 17266295 DOI: 10.1021/jm061232x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Amodiaquine (AQ) and tebuquine are 4-aminoquinoline antimalarials with Mannich base side chain and are highly effective against chloroquine (CQ)-resistant strains of Plasmodium falciparum. Clinical use of AQ has been severely restricted due to hepatoxicity and agranulocytosis side effects associated with its long term use. Lysosomal accumulation and bioactivation to generate reactive quinoneimine metabolite are implicated to be the cause of the observed AQ toxicities. To avoid the quinoneimine formation and thus the toxicity, a series of isotebuquine analogues and their Nomega-oxides with hydroxy group meta to the amino rather than in para position of the aniline moiety were prepared. The new Mannich bases are highly active against both CQ-sensitive (D6) and -resistant (W2 and TM91C235) clones of P. falciparum with IC50 in the range of 0.3-120 ng/mL. New compounds are1000-fold less toxic (IC50 = 0.7-6 microg/mL) to mouse macrophage cell line than to parasite cell lines. Mono-Mannich bases are more active than bis-Mannich bases. Mono-Mannich base 1a (IC50 = 0.3 ng/mL) is 20-fold more active than the corresponding trifluoromethyl analogue 1b. No appreciable difference in either toxicity or efficacy were observed between the new Mannich bases (m-hydroxyaniline derivatives) 1a or 2a and the corresponding p-hydroxyaniline derivatives.
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Affiliation(s)
- Olga V Miroshnikova
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, USA
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Bray PG, Ward SA, O'Neill PM. Quinolines and artemisinin: chemistry, biology and history. Curr Top Microbiol Immunol 2005; 295:3-38. [PMID: 16265885 DOI: 10.1007/3-540-29088-5_1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Plasmodium falciparum is the most important parasitic pathogen in humans, causing hundreds of millions of malaria infections and millions of deaths each year. At present there is no effective malaria vaccine and malaria therapy is totally reliant on the use of drugs. New drugs are urgently needed because of the rapid evolution and spread of parasite resistance to the current therapies. Drug resistance is one of the major factors contributing to the resurgence of malaria, especially resistance to the most affordable drugs such as chloroquine. We need to fully understand the antimalarial mode of action of the existing drugs and the way that the parasite becomes resistant to them in order to design and develop the new therapies that are so urgently needed. In respect of the quinolines and artemisinins, great progress has been made recently in studying the mechanisms of drug action and drug resistance in malaria parasites. Here we summarize from a historical, biological and chemical, perspective the exciting new advances that have been made in the study of these important antimalarial drugs.
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Affiliation(s)
- P G Bray
- Division of Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
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Röwer S, Bienzle U, Weise A, Lambertz U, Forst T, Otchwemah RN, Pfützner A, Mockenhaupt FP. Short communication: high prevalence of the cytochrome P450 2C8*2 mutation in Northern Ghana. Trop Med Int Health 2005; 10:1271-3. [PMID: 16359408 DOI: 10.1111/j.1365-3156.2005.01525.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recently, Ghana has changed the first-line treatment of uncomplicated malaria from chloroquine to amodiaquine (AQ) plus artesunate. AQ may cause adverse events such as agranulocytosis and hepatoxicity. The pro-drug AQ is transformed by cytochrome P450 CYP2C8 to the active metabolite N-desethylaminodiaquine. Several polymorphic variants of CYP2C8 are known, some with reduced activity. In 200 randomly selected children from Northern Ghana, we determined the allele frequencies of the CYP2C8 variants CYP2C8*1 (wild type), CYP2C8*2, CYP2C8*3, and CYP2C8*4. We did not detect CYP2C8*3 and CYP2C8*4, but CYP2C8*2 showed an allele frequency of 0.1675. AQ metabolism in patients with CYP2C8*2 may be impaired, and with an increase of AQ based treatment the risk of severe adverse events may mount.
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Affiliation(s)
- Susanne Röwer
- Institute of Tropical Medicine, Charité-University Medicine Berlin, Berlin, Germany.
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Yang XX, Hu ZP, Chan SY, Zhou SF. Monitoring drug-protein interaction. Clin Chim Acta 2005; 365:9-29. [PMID: 16199025 DOI: 10.1016/j.cca.2005.08.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 08/16/2005] [Accepted: 08/23/2005] [Indexed: 11/25/2022]
Abstract
A variety of therapeutic drugs can undergo biotransformation via Phase I and Phase II enzymes to reactive metabolites that have intrinsic chemical reactivity toward proteins and cause potential organ toxicity. A drug-protein adduct is a protein complex that forms when electrophilic drugs or their reactive metabolite(s) covalently bind to a protein molecule. Formation of such drug-protein adducts eliciting cellular damages and immune responses has been a major hypothesis for the mechanism of toxicity caused by numerous drugs. The monitoring of protein-drug adducts is important in the kinetic and mechanistic studies of drug-protein adducts and establishment of dose-toxicity relationships. The determination of drug-protein adducts can also provide supportive evidence for diagnosis of drug-induced diseases associated with protein-drug adduct formation in patients. The plasma is the most commonly used matrix for monitoring drug-protein adducts due to its convenience and safety. Measurement of circulating antibodies against drug-protein adducts may be used as a useful surrogate marker in the monitoring of drug-protein adducts. The determination of plasma protein adducts and/or relevant antibodies following administration of several drugs including acetaminophen, dapsone, diclofenac and halothane has been conducted in clinical settings for characterizing drug toxicity associated with drug-protein adduct formation. The monitoring of drug-protein adducts often involves multi-step laboratory procedure including sample collection and preliminary preparation, separation to isolate or extract the target compound from a mixture, identification and determination. However, the monitoring of drug-protein adducts is often difficult because of short half-lives of the protein adducts, sampling problem and lack of sensitive analytical techniques for the protein adducts. Currently, chromatographic (e.g. high performance liquid chromatography) and immunological methods (e.g. enzyme-linked immunosorbent assay) are two major techniques used to determine protein adducts of drugs in patients. The present review highlights the importance for clinical monitoring of drug-protein adducts, with an emphasis on methodology and with a further discussion of the application of these techniques to individual drugs and their target proteins.
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Affiliation(s)
- Xiao-Xia Yang
- Department of Pharmacy, Faculty of Science, National University of Singapore, Science Drive 4, Singapore 117543, Singapore
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Kalgutkar AS, Soglia JR. Minimising the potential for metabolic activation in drug discovery. Expert Opin Drug Metab Toxicol 2005; 1:91-142. [PMID: 16922655 DOI: 10.1517/17425255.1.1.91] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Investigations into the role of bioactivation in the pathogenesis of xenobiotic-induced toxicity have been a major area of research since the link between reactive metabolites and carcinogenesis was first reported in the 1930s. Circumstantial evidence suggests that bioactivation of relatively inert functional groups to reactive metabolites may contribute towards certain drug-induced adverse reactions. Reactive metabolites, if not detoxified, can covalently modify essential cellular targets. The identity of the susceptible biomacromolecule(s), and the physiological consequence of its covalent modification, will dictate the resulting toxicological response (e.g., covalent modification of DNA by reactive intermediates derived from procarcinogens that potentially leads to carcinogenesis). The formation of drug-protein adducts often carries a potential risk of clinical toxicities that may not be predicted from preclinical safety studies. Animal models used to reliably predict idiosyncratic drug toxicity are unavailable at present. Furthermore, considering that the frequency of occurrence of idiosyncratic adverse drug reactions (IADRs) is fairly rare (1 in 1000 to 1 in 10,000), it is impossible to detect such phenomena in early clinical trials. Thus, the occurrence of IADRs during late clinical trials or after a drug has been released can lead to an unanticipated restriction in its use and even in its withdrawal. Major themes explored in this review include a comprehensive cataloguing of bioactivation pathways of functional groups commonly utilised in drug design efforts with appropriate strategies towards detection of corresponding reactive intermediates. Several instances wherein replacement of putative structural alerts in drugs associated with IADRs with a latent functionality eliminates the underlying liability are also presented. Examples of where bioactivation phenomenon in drug candidates can be successfully abrogated via iterative chemical interventions are also discussed. Finally, appropriate strategies that aid in potentially mitigating the risk of IADRs are explored, especially in circumstances in which the structural alert is also responsible for the primary pharmacology of the drug candidate and cannot be replaced.
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Affiliation(s)
- Amit S Kalgutkar
- Pfizer Global Research & Development, Pharmacokinetics, Dynamics and Metabolism Department, Groton, CT 06340, USA.
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Zhou S, Chan E, Duan W, Huang M, Chen YZ. Drug bioactivation, covalent binding to target proteins and toxicity relevance. Drug Metab Rev 2005; 37:41-213. [PMID: 15747500 DOI: 10.1081/dmr-200028812] [Citation(s) in RCA: 197] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A number of therapeutic drugs with different structures and mechanisms of action have been reported to undergo metabolic activation by Phase I or Phase II drug-metabolizing enzymes. The bioactivation gives rise to reactive metabolites/intermediates, which readily confer covalent binding to various target proteins by nucleophilic substitution and/or Schiff's base mechanism. These drugs include analgesics (e.g., acetaminophen), antibacterial agents (e.g., sulfonamides and macrolide antibiotics), anticancer drugs (e.g., irinotecan), antiepileptic drugs (e.g., carbamazepine), anti-HIV agents (e.g., ritonavir), antipsychotics (e.g., clozapine), cardiovascular drugs (e.g., procainamide and hydralazine), immunosupressants (e.g., cyclosporine A), inhalational anesthetics (e.g., halothane), nonsteroidal anti-inflammatory drugs (NSAIDSs) (e.g., diclofenac), and steroids and their receptor modulators (e.g., estrogens and tamoxifen). Some herbal and dietary constituents are also bioactivated to reactive metabolites capable of binding covalently and inactivating cytochrome P450s (CYPs). A number of important target proteins of drugs have been identified by mass spectrometric techniques and proteomic approaches. The covalent binding and formation of drug-protein adducts are generally considered to be related to drug toxicity, and selective protein covalent binding by drug metabolites may lead to selective organ toxicity. However, the mechanisms involved in the protein adduct-induced toxicity are largely undefined, although it has been suggested that drug-protein adducts may cause toxicity either through impairing physiological functions of the modified proteins or through immune-mediated mechanisms. In addition, mechanism-based inhibition of CYPs may result in toxic drug-drug interactions. The clinical consequences of drug bioactivation and covalent binding to proteins are unpredictable, depending on many factors that are associated with the administered drugs and patients. Further studies using proteomic and genomic approaches with high throughput capacity are needed to identify the protein targets of reactive drug metabolites, and to elucidate the structure-activity relationships of drug's covalent binding to proteins and their clinical outcomes.
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Affiliation(s)
- Shufeng Zhou
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore.
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