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Koh Jing Jie A, Hussein M, Rao GG, Li J, Velkov T. Drug Repurposing Approaches towards Defeating Multidrug-Resistant Gram-Negative Pathogens: Novel Polymyxin/Non-Antibiotic Combinations. Pathogens 2022; 11:pathogens11121420. [PMID: 36558754 PMCID: PMC9781023 DOI: 10.3390/pathogens11121420] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 11/30/2022] Open
Abstract
Multidrug-resistant (MDR) Gram-negative pathogens remain an unmet public health threat. In recent times, increased rates of resistance have been reported not only to commonly used antibiotics, but also to the last-resort antibiotics, such as polymyxins. More worryingly, despite the current trends in resistance, there is a lack of new antibiotics in the drug-discovery pipeline. Hence, it is imperative that new strategies are developed to preserve the clinical efficacy of the current antibiotics, particularly the last-line agents. Combining conventional antibiotics such as polymyxins with non-antibiotics (or adjuvants), has emerged as a novel and effective strategy against otherwise untreatable MDR pathogens. This review explores the available literature detailing the latest polymyxin/non-antibiotic combinations, their mechanisms of action, and potential avenues to advance their clinical application.
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Affiliation(s)
- Augustine Koh Jing Jie
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Maytham Hussein
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Gauri G. Rao
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jian Li
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Tony Velkov
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
- Correspondence:
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2
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Empel A, Bak A, Kozik V, Latocha M, Cizek A, Jampilek J, Suwinska K, Sochanik A, Zieba A. Towards Property Profiling: SYNTHESIS and SAR Probing of New Tetracyclic Diazaphenothiazine Analogues. Int J Mol Sci 2021; 22:ijms222312826. [PMID: 34884631 PMCID: PMC8658022 DOI: 10.3390/ijms222312826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 11/16/2022] Open
Abstract
A series of new tertiary phenothiazine derivatives containing a quinoline and a pyridine fragment was synthesized by the reaction of 1-methyl-3-benzoylthio-4-butylthioquinolinium chloride with 3-aminopyridine derivatives bearing various substituents on the pyridine ring. The direction and mechanism of the cyclization reaction of intermediates with the structure of 1-methyl-4-(3-pyridyl)aminoquinolinium-3-thiolate was related to the substituents in the 2- and 4-pyridine position. The structures of the compounds were analyzed using 1H, 13C NMR (COSY, HSQC, HMBC) and X-ray analysis, respectively. Moreover, the antiproliferative activity against tumor cells (A549, T47D, SNB-19) and a normal cell line (NHDF) was tested. The antibacterial screening of all the compounds was conducted against the reference and quality control strain Staphylococcus aureus ATCC 29213, three clinical isolates of methicillin-resistant S. aureus (MRSA). In silico computation of the intermolecular similarity was performed using principal component analysis (PCA) and hierarchical clustering analysis (HCA) on the pool of structure/property-related descriptors calculated for the novel tetracyclic diazaphenothiazine derivatives. The distance-oriented property evaluation was correlated with the experimental anticancer activities and empirical lipophilicity as well. The quantitative shape-based comparison was conducted using the CoMSA method in order to indicate the potentially valid steric, electronic and lipophilic properties. Finally, the numerical sampling of similarity-related activity landscape (SALI) provided a subtle picture of the SAR trends.
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Affiliation(s)
- Anna Empel
- Department of Organic Chemistry, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Jagiellońska 4, 41-200 Sosnowiec, Poland;
| | - Andrzej Bak
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland;
- Correspondence: (A.B.); (A.Z.)
| | - Violetta Kozik
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland;
| | - Malgorzata Latocha
- Department of Cell Biology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Jedności 9, 41-200 Sosnowiec, Poland;
| | - Alois Cizek
- Department of Infectious Diseases and Microbiology, Faculty of Veterinary Medicine, University of Veterinary Sciences Brno, Palackeho 1946/1, 61242 Brno, Czech Republic;
| | - Josef Jampilek
- Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 84215 Bratislava, Slovakia;
- Department of Chemical Biology, Faculty of Science, Palacky University Olomouc, Slechtitelu 27, 78371 Olomouc, Czech Republic
| | - Kinga Suwinska
- Faculty of Mathematics and Natural Sciences, Cardinal Stefan Wyszyński University, K. Woycickiego 1/3, 01-938 Warszawa, Poland;
| | - Aleksander Sochanik
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie National Research Institute of Oncology, Wybrzeże AK 15, 44-101 Gliwice, Poland;
| | - Andrzej Zieba
- Department of Organic Chemistry, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia in Katowice, Jagiellońska 4, 41-200 Sosnowiec, Poland;
- Correspondence: (A.B.); (A.Z.)
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Jana S, Empel C, Pei C, Vinh Nguyen T, Koenigs RM. Gold‐catalyzed C−H Functionalization of Phenothiazines with Aryldiazoacetates. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202000962] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sripati Jana
- RWTH Aachen University Institute of Organic Chemistry Landoltweg 1 D-52074 Aachen Germany
| | - Claire Empel
- RWTH Aachen University Institute of Organic Chemistry Landoltweg 1 D-52074 Aachen Germany
- University of New South Wales School of Chemistry Sydney Australia
| | - Chao Pei
- RWTH Aachen University Institute of Organic Chemistry Landoltweg 1 D-52074 Aachen Germany
| | | | - Rene M. Koenigs
- RWTH Aachen University Institute of Organic Chemistry Landoltweg 1 D-52074 Aachen Germany
- University of New South Wales School of Chemistry Sydney Australia
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Mendonça AAS, Coelho CM, Veloso MP, Caldas IS, Gonçalves RV, Teixeira AL, de Miranda AS, Novaes RD. Relevance of Trypanothione Reductase Inhibitors on Trypanosoma cruzi Infection: A Systematic Review, Meta-Analysis, and In Silico Integrated Approach. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8676578. [PMID: 30473742 PMCID: PMC6220389 DOI: 10.1155/2018/8676578] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/14/2018] [Indexed: 02/08/2023]
Abstract
Due to the rudimentary antioxidant defenses in Trypanosoma cruzi, disruptors of redox balance are promising candidates for new antitrypanosomal drugs. We developed an integrated model based on systematic review, meta-analyses, and molecular modeling to evaluate the effect of trypanothione reductase (TR) inhibitors in T. cruzi infections. Our findings indicated that the TR inhibitors analyzed were effective in reducing parasitemia and mortality due to Trypanosoma cruzi infection in animal models. The most investigated drugs (clomipramine and thioridazine) showed no beneficial effects on the occurrence of infection-related electrocardiographic abnormalities or the affinity and density of cardiac β-adrenergic receptors. The affinity between the tested ligands and the active site of TR was confirmed by molecular docking. However, the molecular affinity score was unable to explain TR inhibition and T. cruzi death in vitro or the antiparasitic potential of these drugs when tested in preclinical models of T. cruzi infection. The divergence of in silico, in vitro, and in vivo findings indicated that the anti-T. cruzi effects of the analyzed drugs were not restricted to TR inhibition. As in vivo studies on TR inhibitors are still scarce and exhibit methodological limitations, mechanistic and highly controlled studies are required to improve the quality of evidence.
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Affiliation(s)
- Andréa Aparecida Santos Mendonça
- Institute of Biomedical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
- Department of Structural Biology, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
| | - Camila Morais Coelho
- Faculty of Pharmaceutical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
| | - Marcia Paranho Veloso
- Faculty of Pharmaceutical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
| | - Ivo Santana Caldas
- Institute of Biomedical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
- Department of Pathology and Parasitology, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
| | | | - Antônio Lucio Teixeira
- Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, 30130-100 Minas Gerais, Brazil
| | - Aline Silva de Miranda
- Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, 30130-100 Minas Gerais, Brazil
- Institute of Biological Sciences, Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, 30130-100 Minas Gerais, Brazil
| | - Rômulo Dias Novaes
- Institute of Biomedical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
- Department of Structural Biology, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
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Owens DC. Meet the relatives: a reintroduction to the clinical pharmacology of ‘typical’ antipsychotics (Part 1). ACTA ACUST UNITED AC 2018. [DOI: 10.1192/apt.bp.109.006908] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SummaryA number of pragmatic trials have cast doubt on the concept of ‘atypicality’ in relation to antipsychotic drugs, and some commentators have argued that the dichotomy between ‘typical’ (‘first-generation’) and ‘atypical’ ('second-generation’) compounds is artificial and should be abandoned, leaving the entire class of antipsychotics available for consideration in more individualised treatment planning. However, younger psychiatrists now gain little or no experience in the use of older antipsychotics. This is the first of two articles addressing practical issues for consideration in prescribing the older antipsychotics available in the UK. It covers background, including the fundamental clinical action of antipsychotics, the nature of drug licensing and identification of pharmacological parameters that may be of value in prescribing decisions, and discusses the phenothiazines: chlorpromazine, promazine, levomepromazine, pericyazine, perphenazine, trifluoperazine and prochlorperazine.
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Li G, Zhang J, Li C, Guo Q, Jiang Y, Wei J, Qiu Y, Zhao X, Zhao LL, Lu J, Wan K. Antimycobacterial activity of five efflux pump inhibitors against Mycobacterium tuberculosis clinical isolates. J Antibiot (Tokyo) 2015; 69:173-5. [PMID: 26464012 DOI: 10.1038/ja.2015.101] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/20/2015] [Accepted: 09/07/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Guilian Li
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jingrui Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Laboratory, Shijiazhuang Obstetrics and Gynecology Hospital, the Fourth Hospital of Shijiazhuang, Shijiazhuang, China.,Key Laboratory of Laboratory Medicine, Wenzhou Medical College, Wenzhou, China
| | - Chao Li
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Key Laboratory of Laboratory Medicine, Wenzhou Medical College, Wenzhou, China
| | - Qian Guo
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Pathogenic Biology Institute, University of South China, Hengyang, China
| | - Yi Jiang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jianhao Wei
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Key Laboratory of Laboratory Medicine, Wenzhou Medical College, Wenzhou, China
| | - Yan Qiu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiuqin Zhao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Li-li Zhao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jianxin Lu
- Key Laboratory of Laboratory Medicine, Wenzhou Medical College, Wenzhou, China
| | - Kanglin Wan
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Key Laboratory of Laboratory Medicine, Wenzhou Medical College, Wenzhou, China
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7
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Trypanothione reductase inhibitors: Overview of the action of thioridazine in different stages of Chagas disease. Acta Trop 2015; 145:79-87. [PMID: 25733492 DOI: 10.1016/j.actatropica.2015.02.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 02/18/2015] [Accepted: 02/20/2015] [Indexed: 12/13/2022]
Abstract
Thioridazine (TDZ) is a phenothiazine that has been shown to be one of the most potent phenothiazines to inhibit trypanothione reductase irreversibly. Trypanothione reductase is an essential enzyme for the survival of Trypanosoma cruzi in the host. Here, we reviewed the use of this drug for the treatment of T. cruzi experimental infection. In our laboratory, we have studied the effect of TDZ for the treatment of mice infected with different strains of T. cruzi and treated in the acute or in the chronic phases of the experimental infection, using two different schedules: TDZ at a dose of 80 mg/kg/day, for 3 days starting 1h after infection (acute phase), or TDZ 80 mg/kg/day for 12 days starting 180 days post infection (d.p.i.) (chronic phase). In our experience, the treatment of infected mice, in the acute or in the chronic phases of the infection, with TDZ led to a large reduction in the mortality rates and in the cardiac histological and electrocardiographical abnormalities, and modified the natural evolution of the experimental infection. These analyses reinforce the importance of treatment in the chronic phase to decrease, retard or stop the evolution to chagasic myocardiopathy. Other evidence leading to the use of this drug as a potential chemotherapeutic agent for Chagas disease treatment is also revised.
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8
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Kigondu EM, Njoroge M, Singh K, Njuguna N, Warner DF, Chibale K. Synthesis and synergistic antimycobacterial screening of chlorpromazine and its metabolites. MEDCHEMCOMM 2014. [DOI: 10.1039/c3md00387f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Chlorpromazine (CPZ) metabolites naturally generated in vivo were synthesized via a non-classical Polonovski reaction. CPZ and the synthesized metabolites exhibited clear synergy when tested in combination with a number of antituberculosis drugs.
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Affiliation(s)
| | - Mathew Njoroge
- Department of Chemistry
- University of Cape Town
- Rondebosch 7701, South Africa
| | - Kawaljit Singh
- Department of Chemistry
- University of Cape Town
- Rondebosch 7701, South Africa
| | - Nicholas Njuguna
- Department of Chemistry
- University of Cape Town
- Rondebosch 7701, South Africa
| | - Digby F. Warner
- Institute of Infectious Disease & Molecular Medicine
- University of Cape Town
- Rondebosch 7701, South Africa
- MRC/NHLS/UCT Molecular Mycobacteriology Research Unit and DST/NRF Centre of Excellence for Biomedical Tuberculosis Research
- Department of Clinical Laboratory Sciences
| | - Kelly Chibale
- Department of Chemistry
- University of Cape Town
- Rondebosch 7701, South Africa
- Institute of Infectious Disease & Molecular Medicine
- University of Cape Town
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9
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Abstract
Chagas infection is a major endemic disease affecting Latin American countries. The persistence of Trypanosoma cruzi generates a chronic inflammatory reactivity that induces an immune response directed to the host's tissues. The effectiveness of the treatment in the chronic phase is still unsatisfactory due, amongst other reasons, to the collateral effects of the drugs used. We investigated the effect of clomipramine, a tricyclic antidepressant that, when used as a treatment of T. cruzi-chronically infected mice, inhibits trypanothione reductase, an exclusive and vital enzyme of T. cruzi. Clomipramine improved survival (P<0.05) by diminishing the parasite intensity as demonstrated by PCR studies in the heart and skeletal muscle, and significantly prevented the evolution to fibrosis of the inflammatory infiltrates. Clomipramine could be a good candidate for the treatment of chronic Chagas disease.
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10
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Pascu ML, Danko B, Martins A, Jedlinszki N, Alexandru T, Nastasa V, Boni M, Militaru A, Andrei IR, Staicu A, Hunyadi A, Fanning S, Amaral L. Exposure of chlorpromazine to 266 nm laser beam generates new species with antibacterial properties: contributions to development of a new process for drug discovery. PLoS One 2013; 8:e55767. [PMID: 23405212 PMCID: PMC3566004 DOI: 10.1371/journal.pone.0055767] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 01/04/2013] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Phenothiazines when exposed to white light or to UV radiation undergo a variety of reactions that result in degradation of parental compound and formation of new species. This process is slow and may be sped up with exposure to high energy light such as that produced by a laser. METHODS Varying concentrations of Chlorpromazine Hydrochloride (CPZ) (2-20 mg/mL in distilled water) were exposed to 266 nm laser beam (time intervals: 1-24 hrs). At distinct intervals the irradiation products were evaluated by spectrophotometry between 200-1500 nm, Thin Layer Chromatography, High Pressure Liquid Chromatography (HPLC)-Diode Array Detection, HPLC tandem mass spectrometry, and for activity against the CPZ sensitive test organism Staphylococcus aureus ATCC 25923. RESULTS CPZ exposure to 266 nm laser beam of given energy levels yielded species, whose number increased with duration of exposure. Although the major species produced were Promazine (PZ), hydroxypromazine or PZ sulfoxide, and CPZ sulfoxide, over 200 compounds were generated with exposure of 20 mg/mL of CPZ for 24 hrs. Evaluation of the irradiation products indicated that the bioactivity against the test organism increased despite the total disappearance of CPZ, that is due, most probably, to one or more new species that remain yet unidentified. CONCLUSIONS Exposure of CPZ to a high energy (6.5 mJ) 266 nm laser beam yields rapidly a large number of new and stable species. For biological grade phenothiazines (in other words knowing the impurities in the samples: solvent and solute) this process may be reproducible because one can control within reasonably low experimental errors: the concentration of the parent compound, the laser beam wavelength and average energy, as well as the duration of the exposure time. Because the process is "clean" and rapid, it may offer advantages over the pyrogenically based methods for the production of derivatives.
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Affiliation(s)
- Mihail Lucian Pascu
- Laser Department, National Institute for Laser, Plasma and Radiation Physics, Magurele/Ilfov, Romania.
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Affiliation(s)
- Beena
- Department of Chemistry; University of Delhi; Delhi; 110007; India
| | - Diwan S. Rawat
- Department of Chemistry; University of Delhi; Delhi; 110007; India
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Degradation of the tricyclic antipsychotic drug chlorpromazine under environmental conditions, identification of its main aquatic biotic and abiotic transformation products by LC–MSn and their effects on environmental bacteria. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 889-890:24-38. [DOI: 10.1016/j.jchromb.2012.01.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 01/18/2012] [Accepted: 01/20/2012] [Indexed: 11/17/2022]
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Morak-Młodawska B, Pluta K, Matralis AN, Kourounakis AP. Antioxidant activity of newly synthesized 2,7-diazaphenothiazines. Arch Pharm (Weinheim) 2010; 343:268-73. [PMID: 20232371 DOI: 10.1002/ardp.200900253] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A series of 19 derivatives of 2,7-diazaphenothiazine was synthesized and evaluated for their antioxidant activity bearing in mind the structural similarity with "classical" phenothiazines several of which are considered powerful antioxidants. Among the new derivatives that inhibited in vitro Fe(2+)/ascorbate-induced lipid peroxidation of rat liver microsomal membranes, several exhibited significant antioxidant activity with IC(50 )values in the range of 64-125 microM. Although N-substitution led to a variable degree of antioxidant activity, the latter appears to correlate with the lipophilicity (expressed as clogP values) of the substituted derivatives. Reduced lipophilicity may also explain the relatively lower protection offered by these derivatives against lipid peroxidation when compared to their "classical" phenothiazine counterparts. Thus, modification of the phenothiazine structure by a substitution of two benzene rings with pyridine rings to form this new type of azaphenothiazines does not enhance antioxidant activity, although it retains it.
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Affiliation(s)
- Beata Morak-Młodawska
- Department of Organic Chemistry, The Medical University of Silesia, Sosnowiec, Poland
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14
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Rahbar M, Mehrgan H, Hadji-nejad S. Enhancement of vancomycin activity by phenothiazines against vancomycin-resistant Enterococcus faecium in vitro. Basic Clin Pharmacol Toxicol 2010; 107:676-9. [PMID: 20353486 DOI: 10.1111/j.1742-7843.2010.00558.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The antimicrobial and resistance-reversal activities of seven phenothiazine derivatives were evaluated against vancomycin-sensitive Enterococcus faecalis ATCC 29212, vancomycin resistant E. faecalis ATCC 51299 and ten vancomycin-resistant E. faecium strains originating from human infections. Minimum inhibitory concentrations (MIC) of the compounds were determined by agar dilution method, and synergy between phenothiazines and vancomycin was investigated using Checkerboard (microbroth dilution) technique. We found that all enterococci strains, regardless of their susceptibility to vancomycin, were inhibited by phenothiazines at concentrations varying from 8 to 256 microg/ml, with thiethylperazine being the most potent inhibitory agent. Besides, all the phenothiazines showed partial synergy with vancomycin and could lessen MIC of vancomycin from 512 to 8 microg/ml at their sub-inhibitory concentrations. The highest reduction in MIC was observed with chlorpromazine (32 times); however, thiethylperazine and promethazine stood next (24 times). Although resistance modification was observed at concentrations higher than those that phenothiazines reach in vivo, the potential offered by non-antibiotics justify further animal experiments as well as clinical trials to establish their clinical relevance.
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Affiliation(s)
- Mohammad Rahbar
- Department of Microbiology, Reference Health Laboratories, Ministry of Health, Tehran, Iran
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Pluta K, Morak-Młodawska B, Suwińska K, Jeleń M. Alkylations of 10H-2,7-Diazaphenothiazine to Alkyl-2,7-diazaphenothiazinium Salts and 7-Alkyl-2,7-diazaphenothiazines. HETEROCYCLES 2010. [DOI: 10.3987/com-10-12007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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17
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Dutta NK, Annadurai S, Mazumdar K, Dastidar SG, Kristiansen JE, Molnar J, Martins M, Amaral L. Potential management of resistant microbial infections with a novel non-antibiotic: the anti-inflammatory drug diclofenac sodium. Int J Antimicrob Agents 2007; 30:242-9. [PMID: 17644318 DOI: 10.1016/j.ijantimicag.2007.04.018] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Revised: 04/26/2007] [Accepted: 04/30/2007] [Indexed: 10/23/2022]
Abstract
Diclofenac sodium (Dc), an anti-inflammatory agent, has remarkable inhibitory action both against drug-sensitive and drug-resistant clinical isolates of various Gram-positive and Gram-negative bacteria. The aim of this study was to determine the ability of Dc to protect mice from a virulent Salmonella infection. Dc injected at 1.5 microg/g and 3.0 microg/g mouse body weight significantly protected animals from the lethality of Salmonella infection. As was the case for the in vitro interaction, Dc in combination with streptomycin was even more effective. The non-antibiotic drug Dc has potential for the management of problematic antibiotic-resistant bacterial infections.
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Affiliation(s)
- Noton Kumar Dutta
- Institute of Laboratory Animal Resources, Laboratory Animal Medicine, College of Veterinary Medicine, 85-Dong, 733-Ho, Seoul National University, San 56-1, Sillim 9 Dong, Gwanakgu, Seoul, South Korea
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18
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Abstract
The emergence of multiresistant bacterial strains and the continuing burden of infectious disease globally point to the urgent need for novel affordable antimicrobial drugs. Thioridazine is a phenothiazine antipsychotic drug with well-recognized antimicrobial activity, but this property has not been harnessed for clinical use as a result of its central nervous system and cardiac side-effects. The cardiotoxicity of thioridazine has recently been shown to be structurally specific at a molecular level, whereas its antimicrobial properties are shared by a number of phenothiazine analogues. This raises the possibility that its enantiomers or its inactive metabolite, the ring sulphoxide, may act as a lead compound in the future development of antimicrobial drugs to face the new challenges in infectious disease.
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Weisman JL, Liou AP, Shelat AA, Cohen FE, Guy RK, DeRisi JL. Searching for new antimalarial therapeutics amongst known drugs. Chem Biol Drug Des 2007; 67:409-16. [PMID: 16882315 PMCID: PMC1592519 DOI: 10.1111/j.1747-0285.2006.00391.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The need to discover and develop new antimalarial therapeutics is overwhelming. The annual mortality attributed to malaria, currently approximately 2.5 million, is increasing due primarily to widespread resistance to currently used drugs. One strategy to identify new treatment alternatives for malaria is to examine libraries of diverse compounds for the possible identification of novel scaffolds. Beginning with libraries of drug or drug-like compounds is an ideal starting point because, in the case of approved drugs, substantial pharmacokinetic and toxicologic data should be available for each compound series. We have employed a high-throughput screen of the MicroSource Spectrum and Killer Collections, a library of known drugs, bioactive compounds, and natural products. Our screening assay identifies compounds that inhibit growth of Plasmodium falciparum cultured in human erythrocytes. We have identified 36 novel inhibitors of P. falciparum, of which 19 are therapeutics, and five of these drugs exhibit effective 50% inhibitory concentrations within similar ranges to therapeutic serum concentrations for their recently indicated uses: propafenone, thioridazine, chlorprothixene, perhexiline, and azlocillin. The findings we report here indicate that this is an effective strategy to identify novel scaffolds and therefore aid in antimalarial drug discovery efforts.
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Affiliation(s)
- Jennifer L Weisman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94158-2542, USA
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20
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Martins M, Schelz Z, Martins A, Molnar J, Hajös G, Riedl Z, Viveiros M, Yalcin I, Aki-Sener E, Amaral L. In vitro and ex vivo activity of thioridazine derivatives against Mycobacterium tuberculosis. Int J Antimicrob Agents 2007; 29:338-40. [PMID: 17239569 DOI: 10.1016/j.ijantimicag.2006.10.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2006] [Revised: 10/13/2006] [Accepted: 10/17/2006] [Indexed: 11/30/2022]
Abstract
Thioridazine (TZ) has previously been shown by us to have in vitro and ex vivo activity against antibiotic-susceptible and multidrug-resistant Mycobacterium tuberculosis (MDRTB). Because current therapy of MDRTB is highly problematic even when all five 'first line of defence' drugs are employed, there is a need for effective antituberculosis drugs. New derivatives of TZ were synthesised and their in vitro activity against a reference strain of M. tuberculosis was evaluated with the aid of the BACTEC 460 system. Derivatives that presented significant activity were evaluated by ex vivo studies and were shown to enhance the killing of intracellular M. tuberculosis.
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Affiliation(s)
- Marta Martins
- Unidade de Micobacterias, UPMM, Instituto de Higiene e Medicina Tropical, Universidade de Lisboa, Rua da Junqueira 96, 1394-008 Lisbon, Portugal
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21
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Amaral L, Martins M, Viveiros M. Enhanced killing of intracellular multidrug-resistant Mycobacterium tuberculosis by compounds that affect the activity of efflux pumps. J Antimicrob Chemother 2007; 59:1237-46. [PMID: 17218448 DOI: 10.1093/jac/dkl500] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Whereas human neutrophils are effective and efficient killers of bacteria, macrophages such as those derived from monocytes are almost devoid of killing activity. Nevertheless, monocytes can be transformed into effective killers of mycobacteria or staphylococci when exposed to clinical concentrations of a phenothiazine or to inhibitors of efflux pumps (reserpine and verapamil), or to ouabain, an inhibitor of K(+) transport. Because the rates of multidrug-resistant Mycobacterium tuberculosis (MDR-TB) continue to escalate globally, and because no new effective drug has been made available for almost 40 years, compounds that enhance the killing activity of monocytes against MDR-TB are obviously needed. This review covers the specific characteristics of MDR-TB, identifies a variety of agents that address these characteristics and therefore have potential for managing MDR-TB. Because the mechanism by which these agents enhance the killing of intracellular bacteria is important for the intelligent design of new anti-tubercular agents, the review correlates the mechanisms by which these agents manifest their effects. Lastly, a model is presented which describes the mechanisms by which distinct efflux pumps of the phagosome-lysosome complex are inhibited by agents that are known to inhibit K(+) flux. The model also predicts the existence of a K(+) activated exchange (pump) that is probably located in the membrane that delineates the lysosome. This putative pump, which is immune to inhibitors of K+ flux, is identified as being the cause for the acidification of the lysosome thereby activating its hydrolytic enzymes. Because the non-killer macrophage can be transformed into an effective killer by a variety of compounds that inhibit K(+) transport, perhaps it would be wise to develop drugs that enhance the killing activity of these cells inasmuch as this approach would not be subject to any resistance, as is the eventual case for conventional antibiotics.
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Affiliation(s)
- Leonard Amaral
- Unidade de Micobacterias, UPMM, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 96, Lisboa, Portugal.
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Alisky JM, Chertkova EL, Iczkowski KA. Drug interactions and pharmacogenetic reactions are the basis for chloroquine and mefloquine-induced psychosis. Med Hypotheses 2006; 67:1090-4. [PMID: 16843615 DOI: 10.1016/j.mehy.2006.01.059] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Accepted: 01/25/2006] [Indexed: 11/23/2022]
Abstract
BACKGROUND Chloroquine and mefloquine used for prophylaxis and treatment of malaria sometimes causes severe mental status changes, through mechanisms that are poorly understood. PRESENTATION OF THE HYPOTHESIS Psychosis is caused by interactions with other drugs or by pharmacogenetic vulnerabilities that cause heightened responses to chloroquine or mefloquine alone, mediated through dopamine, acetylcholine, serotonin, P-glycoprotein, inhibited cortical activity, deranged calcium homeostasis, and impaired synaptogenesis. TESTING THE HYPOTHESIS Retrospective studies can identify all other drugs taken coincident with chloroquine or mefloquine psychosis. Various genes from patients could be cloned and compared to those from individuals who tolerated chloroquine and mefloquine, culminating with transgenic animal studies. Identification of candidate genes may be aided by pharmacogenomic analysis of single nucleotide polymorphism maps. Finally, prospective studies with cerebrospinal fluid analysis and PET scanning could help verify the hypothesis. IMPLICATIONS OF THE HYPOTHESIS If this hypothesis is correct, the incidence of chloroquine and mefloquine psychosis can be greatly reduced by avoiding interacting medications and by conducting genetic screening prior to initiating chloroquine and mefloquine. Validation of the hypothesis would also provide a paradigm to follow for avoiding neuropsychiatric side effects if antidepressants and neuroleptics are used to overcome chloroquine resistance, if new antimalarial drugs chemically related to chloroquine and mefloquine are developed and if chloroquine and mefloquine are used for non-malarial applications such as HIV and cancer.
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Affiliation(s)
- Joseph M Alisky
- Marshfield Clinic Research Foundation, 1000 Oak Avenue, Marshfield, WI 54449, USA
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23
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Eghbal MA, Tafazoli S, Pennefather P, O'Brien PJ. Peroxidase catalysed formation of cytotoxic prooxidant phenothiazine free radicals at physiological pH. Chem Biol Interact 2005; 151:43-51. [PMID: 15607761 DOI: 10.1016/j.cbi.2004.10.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2004] [Revised: 10/25/2004] [Accepted: 10/25/2004] [Indexed: 11/19/2022]
Abstract
The antipsychotic phenothiazines may have other therapeutic applications because of their ability to kill bacteria, plasmids and tumor cells. They are also known to undergo a peroxidase-catalysed oxidation to form cation radicals that are stable at acid pH, but are not detected at a neutral pH. The objective of this project was to determine whether phenothiazine cation radical metabolites could cause oxidative stress at a neutral pH resulting in cytotoxicity. At a neutral pH, catalytic amounts of phenothiazines were found to be oxidised by a peroxidase/H2O2 system and also caused ascorbate, GSH and NADH cooxidation. NADH and GSH co-oxidation was accompanied by oxygen uptake and was increased by the addition of catalytic amounts of superoxide dismutase, indicating that the superoxide radical was formed. The phenothazines were different from other peroxidase substrates in that the NADH, ascorbate or GSH cooxidation was faster at pH 6.0 than pH 7.4, thereby partly reflecting the cation radical stability. The order of catalytic effectiveness found was promazine > chlorpromazine > trifluoperazine. Peroxidase/H2O2 also markedly increased phenothiazine cytotoxicity towards isolated rat hepatocytes at nontoxic phenothiazine concentrations. At both pH 6.0 and 7.4, the same order of phenothiazine catalytic effectiveness was observed as seen in the co-oxidation experiments. Cytotoxicity to hepatocytes could be attributed to oxidative stress as most hepatocyte glutathione oxidation and lipid peroxidation preceded phenothiazine induced cytotoxicity and that cytotoxicity was prevented by the antioxidant butylated hydroxyanisole. This hepatocyte/peroxidase/H2O2 system could be a useful model for studying drug induced idiosyncratic hepatic injury enhanced by inflammation.
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Affiliation(s)
- Mohammad A Eghbal
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, East Azarbaijan, Iran
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24
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Meissner PE, Mandi G, Witte S, Coulibaly B, Mansmann U, Rengelshausen J, Schiek W, Jahn A, Sanon M, Tapsoba T, Walter-Sack I, Mikus G, Burhenne J, Riedel KD, Schirmer H, Kouyaté B, Müller O. Safety of the methylene blue plus chloroquine combination in the treatment of uncomplicated falciparum malaria in young children of Burkina Faso [ISRCTN27290841]. Malar J 2005; 4:45. [PMID: 16179085 PMCID: PMC1262758 DOI: 10.1186/1475-2875-4-45] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Accepted: 09/22/2005] [Indexed: 11/21/2022] Open
Abstract
Background Safe, effective and affordable drug combinations against falciparum malaria are urgently needed for the poor populations in malaria endemic countries. Methylene blue (MB) combined with chloroquine (CQ) has been considered as one promising new regimen. Objectives The primary objective of this study was to evaluate the safety of CQ-MB in African children with uncomplicated falciparum malaria. Secondary objectives were to assess the efficacy and the acceptance of CQ-MB in a rural population of West Africa. Methods In this hospital-based randomized controlled trial, 226 children (6–59 months) with uncomplicated falciparum malaria were treated in Burkina Faso. The children were 4:1 randomized to CQ-MB (n = 181; 25 mg/kg CQ and 12 mg/kg MB over three days) or CQ (n = 45; 25 mg/kg over three days) respectively. The primary outcome was the incidence of severe haemolysis or other serious adverse events (SAEs). Efficacy outcomes were defined according to the WHO 2003 classification system. Patients were hospitalized for four days and followed up until day 14. Results No differences in the incidence of SAEs and other adverse events were observed between children treated with CQ-MB (including 24 cases of G6PD deficiency) compared to children treated with CQ. There was no case of severe haemolysis and also no significant difference in mean haemoglobin between study groups. Treatment failure rates were 53.7% (95% CI [37.4%; 69.3%]) in the CQ group compared to 44.0% (95% CI [36.3%; 51.9%]) in the CQ-MB group. Conclusion MB is safe for the treatment of uncomplicated falciparum malaria, even in G6PD deficient African children. However, the efficacy of the CQ-MB combination has not been sufficient at the MB dose used in this study. Future studies need to assess the efficacy of MB at higher doses and in combination with appropriate partner drugs.
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Affiliation(s)
- Peter E Meissner
- Department of Tropical Hygiene and Public Health, Ruprecht-Karls-University, INF 324, 69120 Heidelberg,, Germany
- Department of Paediatrics IV Neonatology, Ruprecht-Karls-University, Heidelberg, Germany
| | - Germain Mandi
- Centre de Recherche en Santé de Nouna, Burkina Faso, POB 02, Nouna, Burkina Faso
| | - Steffen Witte
- Institute of Medical Biometrics and Informatics, Ruprecht-Karls-University, Heidelberg, Germany
| | - Boubacar Coulibaly
- Centre de Recherche en Santé de Nouna, Burkina Faso, POB 02, Nouna, Burkina Faso
| | - Ulrich Mansmann
- Institute of Medical Biometrics and Informatics, Ruprecht-Karls-University, Heidelberg, Germany
- Institute of Medical Information, Biometry, and Epidemiology, Ludwig-Maximilians-University, Munich, Germany
| | - Jens Rengelshausen
- Department of Internal Medicine VI, Clinical Pharmacology and Pharmacoepidemiology, Ruprecht-Karls University, Heidelberg, Germany
| | | | - Albrecht Jahn
- Department of Tropical Hygiene and Public Health, Ruprecht-Karls-University, INF 324, 69120 Heidelberg,, Germany
| | - Mamadou Sanon
- Centre de Recherche en Santé de Nouna, Burkina Faso, POB 02, Nouna, Burkina Faso
| | - Théophile Tapsoba
- Centre de Recherche en Santé de Nouna, Burkina Faso, POB 02, Nouna, Burkina Faso
| | - Ingeborg Walter-Sack
- Department of Internal Medicine VI, Clinical Pharmacology and Pharmacoepidemiology, Ruprecht-Karls University, Heidelberg, Germany
| | - Gerd Mikus
- Department of Internal Medicine VI, Clinical Pharmacology and Pharmacoepidemiology, Ruprecht-Karls University, Heidelberg, Germany
| | - Jürgen Burhenne
- Department of Internal Medicine VI, Clinical Pharmacology and Pharmacoepidemiology, Ruprecht-Karls University, Heidelberg, Germany
| | - Klaus-Dieter Riedel
- Department of Internal Medicine VI, Clinical Pharmacology and Pharmacoepidemiology, Ruprecht-Karls University, Heidelberg, Germany
| | - Heiner Schirmer
- Biochemistry Center, Ruprecht-Karls-University, Heidelberg, Germany
| | - Bocar Kouyaté
- Centre de Recherche en Santé de Nouna, Burkina Faso, POB 02, Nouna, Burkina Faso
| | - Olaf Müller
- Department of Tropical Hygiene and Public Health, Ruprecht-Karls-University, INF 324, 69120 Heidelberg,, Germany
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Abstract
The phenothiazinium salt methylene blue [3,7-bis(dimethylamino)phenothiazinium chloride] is the oldest known synthetic antimalarial drug, its clinical efficacy having been reported in 1891. The role of methylene blue in the evolution of the modern antimalarial armoury is often unappreciated, yet it can be linked directly to standard drugs such as chloroquine and its congeners. Also, in the face of increasing plasmodial resistance to modern antimalarials, phenothiazinium derivatives have again featured as lead compounds in drug research. The precise mode of action of methylene blue and its commercial analogues against Plasmodium spp. remains a cause for conjecture, having been variously described as nucleic acid intercalation, food vacuole basification, parasite redox cycle interference and haem polymerization inhibition. That the activity of the series may be due to more than one route - i.e. a multifactorial activity - underlines the utility of these compounds in antimalarial research either as single drugs or as adjuvants (partners in a drug combination), particularly in the face of resistant parasitic strains.
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26
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Mandi G, Witte S, Meissner P, Coulibaly B, Mansmann U, Rengelshausen J, Schiek W, Jahn A, Sanon M, Wüst K, Walter-Sack I, Mikus G, Burhenne J, Riedel KD, Schirmer H, Kouyaté B, Müller O. Safety of the combination of chloroquine and methylene blue in healthy adult men with G6PD deficiency from rural Burkina Faso. Trop Med Int Health 2005; 10:32-8. [PMID: 15655011 DOI: 10.1111/j.1365-3156.2004.01356.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
New drug combinations against falciparum malaria which are both effective and affordable for Sub-Saharan African populations are urgently needed. The combination of the well-known drugs chloroquine (CQ) and methylene blue (MB) is such a promising new regimen. However, there is some concern that MB could cause development of haemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, a condition which is prevalent in malaria-endemic regions. Against this background, 74 G6PD-deficient but otherwise healthy adult men were given a 3-day oral regimen of a total of 1500 mg CQ and 780 mg MB in the District Hospital of Nouna in north-western Burkina Faso. Haemolysis did not occur, haemoglobin levels remained stable or even rose in the study participants, and the drug regimen was well tolerated. Therefore, standard dosages of MB appear to be safe in G6PD-deficient African populations with predominantly class III G6PD deficiency.
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Maynes JT, Garen C, Cherney MM, Newton G, Arad D, Av-Gay Y, Fahey RC, James MNG. The crystal structure of 1-D-myo-inosityl 2-acetamido-2-deoxy-alpha-D-glucopyranoside deacetylase (MshB) from Mycobacterium tuberculosis reveals a zinc hydrolase with a lactate dehydrogenase fold. J Biol Chem 2003; 278:47166-70. [PMID: 12958317 DOI: 10.1074/jbc.m308914200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mycothiol (1-D-myo-inosityl 2-(N-acetyl-L-cysteinyl)amido-2-deoxy-alpha-D-glucopyranoside, MSH or AcCys-GlcN-inositol (Ins)) is the major reducing agent in actinomycetes, including Mycobacterium tuberculosis. The biosynthesis of MSH involves a deacetylase that removes the acetyl group from the precursor GlcNAc-Ins to yield GlcN-Ins. The deacetylase (MshB) corresponds to Rv1170 of M. tuberculosis with a molecular mass of 33,400 Da. MshB is a Zn2+ metalloprotein, and the deacetylase activity is completely dependent on the presence of a divalent metal cation. We have determined the x-ray crystallographic structure of MshB, which reveals a protein that folds in a manner resembling lactate dehydrogenase in the N-terminal domain and a C-terminal domain consisting of two beta-sheets and two alpha-helices. The zinc binding site is in the N-terminal domain occupying a position equivalent to that of the NAD+ co-factor of lactate dehydrogenase. The Zn2+ is 5 coordinate with 3 residues from MshB (His-13, Asp-16, His-147) and two water molecules. One water would be displaced upon binding of substrate (GlcNAc-Ins); the other is proposed as the nucleophilic water assisted by the general base carboxylate of Asp-15. In addition to the Zn2+ providing electrophilic assistance in the hydrolysis, His-144 imidazole could form a hydrogen bond to the oxyanion of the tetrahedral intermediate. The extensive sequence identity of MshB, the deacetylase, with mycothiol S-conjugate amidase, an amide hydrolase that mediates detoxification of mycothiol S-conjugate xenobiotics, has allowed us to construct a faithful model of the catalytic domain of mycothiol S-conjugate amidase based on the structure of MshB.
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Affiliation(s)
- Jason T Maynes
- Canadian Institutes of Health Research, Group in Protein Structure and Function, Department of Biochemistry, Faculty of Medicine, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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Ordway D, Viveiros M, Leandro C, Arroz MJ, Amaral L. Intracellular activity of clinical concentrations of phenothiazines including thioridiazine against phagocytosed Staphylococcus aureus. Int J Antimicrob Agents 2002; 20:34-43. [PMID: 12127709 DOI: 10.1016/s0924-8579(02)00110-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effect of thioridazine (TZ) was studied on the killing activity of human peripheral blood monocyte derived macrophages (HPBMDM) and of human macrophage cell line THP-1 at extracellular concentrations below those achievable clinically. These macrophages have nominal killing activity against bacteria and therefore, would not influence any activity that the compounds may have against intracellular localised Staphylococcus aureus. The results indicated that whereas TZ has an in vitro minimum inhibitory concentration (MIC) against the strains of S. aureus of 18, 0.1 mg/l of TZ in the medium completely inhibits the growth of S. aureus that has been phagocytosed by macrophages. The latter concentration was non-toxic to macrophages, did not cause cellular expression of activation marker CD69 nor induction of CD3+ T cell production of IFN-gamma, but blocked cellular proliferation and down-regulated the production of T cell-derived cytokines (IFN-gamma, IL-5). These results suggest that TZ induces intracellular bactericidal activities independent of the capacity to generate Type 1 responses against S. aureus.
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Affiliation(s)
- Diane Ordway
- Unit of Mycobacteriology, Department of Mycobacteriology, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira 96, 1349-019 Lisboa, Portugal
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