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Patel OPS, Beteck RM, Legoabe LJ. Antimalarial application of quinones: A recent update. Eur J Med Chem 2020; 210:113084. [PMID: 33333397 DOI: 10.1016/j.ejmech.2020.113084] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 11/27/2020] [Accepted: 12/01/2020] [Indexed: 12/28/2022]
Abstract
Atovaquone belongs to a naphthoquinone class of drugs and is used in combination with proguanil (Malarone) for the treatment of acute, uncomplicated malaria caused by Plasmodium falciparum (including chloroquine-resistant P. falciparum/P. vivax). Numerous quinone-derived compounds have attracted considerable attention in the last few decades due to their potential in antimalarial drug discovery. Several semi-synthetic derivatives of natural quinones, synthetic quinones (naphtho-/benzo-quinone, anthraquinones, thiazinoquinones), and quinone-based hybrids were explored for their in vitro and in vivo antimalarial activities. A careful literature survey revealed that this topic has not been compiled as a review article so far. Therefore, we herein summarise the recent discovery (the year 2009-2020) of quinone based antimalarial compounds in chronological order. This compilation would be very useful towards the exploration of novel quinone-derived compounds against malarial parasites with promising efficacy and lesser side effects.
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Affiliation(s)
- Om P S Patel
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa.
| | - Richard M Beteck
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa
| | - Lesetja J Legoabe
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Private Bag X6001, Potchefstroom, 2520, South Africa.
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2
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Benoit SL, Maier RJ, Sawers RG, Greening C. Molecular Hydrogen Metabolism: a Widespread Trait of Pathogenic Bacteria and Protists. Microbiol Mol Biol Rev 2020; 84:e00092-19. [PMID: 31996394 PMCID: PMC7167206 DOI: 10.1128/mmbr.00092-19] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Pathogenic microorganisms use various mechanisms to conserve energy in host tissues and environmental reservoirs. One widespread but often overlooked means of energy conservation is through the consumption or production of molecular hydrogen (H2). Here, we comprehensively review the distribution, biochemistry, and physiology of H2 metabolism in pathogens. Over 200 pathogens and pathobionts carry genes for hydrogenases, the enzymes responsible for H2 oxidation and/or production. Furthermore, at least 46 of these species have been experimentally shown to consume or produce H2 Several major human pathogens use the large amounts of H2 produced by colonic microbiota as an energy source for aerobic or anaerobic respiration. This process has been shown to be critical for growth and virulence of the gastrointestinal bacteria Salmonella enterica serovar Typhimurium, Campylobacter jejuni, Campylobacter concisus, and Helicobacter pylori (including carcinogenic strains). H2 oxidation is generally a facultative trait controlled by central regulators in response to energy and oxidant availability. Other bacterial and protist pathogens produce H2 as a diffusible end product of fermentation processes. These include facultative anaerobes such as Escherichia coli, S Typhimurium, and Giardia intestinalis, which persist by fermentation when limited for respiratory electron acceptors, as well as obligate anaerobes, such as Clostridium perfringens, Clostridioides difficile, and Trichomonas vaginalis, that produce large amounts of H2 during growth. Overall, there is a rich literature on hydrogenases in growth, survival, and virulence in some pathogens. However, we lack a detailed understanding of H2 metabolism in most pathogens, especially obligately anaerobic bacteria, as well as a holistic understanding of gastrointestinal H2 transactions overall. Based on these findings, we also evaluate H2 metabolism as a possible target for drug development or other therapies.
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Affiliation(s)
- Stéphane L Benoit
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Robert J Maier
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - R Gary Sawers
- Institute of Microbiology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Chris Greening
- School of Biological Sciences, Monash University, Clayton, VIC, Australia
- Department of Microbiology, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia
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3
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Okada-Junior C, Monteiro GC, Aguiar ACC, Batista VS, de Souza JO, Souza GE, Bueno RV, Oliva G, Nascimento-Júnior NM, Guido RVC, Bolzani VS. Phthalimide Derivatives with Bioactivity against Plasmodium falciparum: Synthesis, Evaluation, and Computational Studies Involving bc 1 Cytochrome Inhibition. ACS OMEGA 2018; 3:9424-9430. [PMID: 31459076 PMCID: PMC6644792 DOI: 10.1021/acsomega.8b01062] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 08/02/2018] [Indexed: 06/10/2023]
Abstract
We describe herein the design and synthesis of N-phenyl phthalimide derivatives with inhibitory activities against Plasmodium falciparum (sensitive and resistant strains) in the low micromolar range and noticeable selectivity indices against human cells. The best inhibitor, 4-amino-2-(4-methoxyphenyl)isoindoline-1,3-dione (10), showed a slow-acting mechanism similar to that of atovaquone. Enzymatic assay indicated that 10 inhibited P. falciparum cytochrome bc 1 complex. Molecular docking studies suggested the binding mode of the best hit to Qo site of the cytochrome bc 1 complex. Our findings suggest that 10 is a promising candidate for hit-to-lead development.
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Affiliation(s)
- Celso
Yassuo Okada-Junior
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
| | - Gustavo Claro Monteiro
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
| | - Anna Caroline Campos Aguiar
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Victor Sousa Batista
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
| | - Juliana Oliveira de Souza
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Guilherme Eduardo Souza
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Renata Vieira Bueno
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Glaucius Oliva
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Nailton M. Nascimento-Júnior
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
| | - Rafael Victorio Carvalho Guido
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Vanderlan Silva Bolzani
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
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Kim EE, Onyango EO, Pace JR, Abbot TM, Fu L, Gribble GW. Three-component reductive alkylation of 2-hydroxy-1, 4-naphthoquinones with lactols. Tetrahedron Lett 2016; 57:864-867. [PMID: 39105101 PMCID: PMC11299892 DOI: 10.1016/j.tetlet.2016.01.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lactols II, obtained by DIBAL reduction of their corresponding lactones I, in equilibrium with their hydroxyaldehyde tautomers III were used in a three-component reductive alkylation with 2-hydroxy-1,4-naphthoquinone to give a series of 3-alkylated 2-hydroxy-1,4-naphthoquinone derivatives IV.
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Affiliation(s)
- Eliana E. Kim
- Department of Chemistry, Dartmouth College, Hanover, NH 03755-3564, USA
| | - Evans O. Onyango
- Department of Chemistry, Dartmouth College, Hanover, NH 03755-3564, USA
| | - Jennifer R. Pace
- Department of Chemistry, Dartmouth College, Hanover, NH 03755-3564, USA
| | - Timothy M. Abbot
- Department of Chemistry, Dartmouth College, Hanover, NH 03755-3564, USA
| | - Liangfeng Fu
- Department of Chemistry, Dartmouth College, Hanover, NH 03755-3564, USA
| | - Gordon W. Gribble
- Department of Chemistry, Dartmouth College, Hanover, NH 03755-3564, USA
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Kim EE, Onyango EO, Fu L, Gribble GW. Synthesis of a monofluoro 3-alkyl-2-hydroxy-1,4-naphthoquinone: a potential anti-malarial drug. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.10.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Esser L, Yu CA, Xia D. Structural basis of resistance to anti-cytochrome bc₁ complex inhibitors: implication for drug improvement. Curr Pharm Des 2014; 20:704-24. [PMID: 23688079 PMCID: PMC4788501 DOI: 10.2174/138161282005140214163327] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 05/09/2013] [Indexed: 11/22/2022]
Abstract
The emergence of drug resistance has devastating economic and social consequences, a testimonial of which is the rise and fall of inhibitors against the respiratory component cytochrome bc₁ complex, a time tested and highly effective target for disease control. Unfortunately, the mechanism of resistance is a multivariate problem, including primarily mutations in the gene of the cytochrome b subunit but also activation of alternative pathways of ubiquinol oxidation and pharmacokinetic effects. There is a considerable interest in designing new bc₁ inhibitors with novel modes of binding and lower propensity to induce the development of resistance. The accumulation of crystallographic data of bc₁ complexes with and without inhibitors bound provides the structural basis for rational drug design. In particular, the cytochrome b subunit offers two distinct active sites that can be targeted for inhibition - the quinol oxidation site and the quinone reduction site. This review brings together available structural information of inhibited bc₁ by various quinol oxidation- and reductionsite inhibitors, the inhibitor binding modes, conformational changes upon inhibitor binding of side chains in the active site and large scale domain movements of the iron-sulfur protein subunit. Structural data analysis provides a clear understanding of where and why existing inhibitors fail and points towards promising alternatives.
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Affiliation(s)
| | | | - Di Xia
- Laboratory of Cell Biology, NCI, NIH, 37 Convent Dr., Building 37, Room 2122C, Bethesda MD 20892.
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Schuck DC, Ferreira SB, Cruz LN, da Rocha DR, Moraes MS, Nakabashi M, Rosenthal PJ, Ferreira VF, Garcia CRS. Biological evaluation of hydroxynaphthoquinones as anti-malarials. Malar J 2013; 12:234. [PMID: 23841934 PMCID: PMC3726445 DOI: 10.1186/1475-2875-12-234] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 06/12/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The hydroxynaphthoquinones have been extensively investigated over the past 50 years for their anti-malarial activity. One member of this class, atovaquone, is combined with proguanil in Malarone®, an important drug for the treatment and prevention of malaria. METHODS Anti-malarial activity was assessed in vitro for a series of 3-alkyl-2-hydroxy-1,4-naphthoquinones (N1-N5) evaluating the parasitaemia after 48 hours of incubation. Potential cytotoxicity in HEK293T cells was assessed using the MTT assay. Changes in mitochondrial membrane potential of Plasmodium were measured using the fluorescent dye Mitrotracker Red CMXROS. RESULTS Four compounds demonstrated IC50s in the mid-micromolar range, and the most active compound, N3, had an IC50 of 443 nM. N3 disrupted mitochondrial membrane potential, and after 1 hour presented an IC50ΔΨmit of 16 μM. In an in vitro cytotoxicity assay using HEK 293T cells N3 demonstrated no cytotoxicity at concentrations up to 16 μM. CONCLUSIONS N3 was a potent inhibitor of mitochondrial electron transport, had nanomolar activity against cultured Plasmodium falciparum and showed minimal cytotoxicity. N3 may serve as a starting point for the design of new hydroxynaphthoquinone anti-malarials.
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Affiliation(s)
- Desiree C Schuck
- Departamento de Fisiologia, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Sabrina B Ferreira
- Departamento de Química Orgânica, Universidade Federal Fluminense, Niterói 24020-141, Brazil
- Departamento de Química Orgânica, Universidade Federal do Rio de Janeiro, Macaé 27930-560, Brazil
| | - Laura N Cruz
- Departamento de Fisiologia, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - David R da Rocha
- Departamento de Química Orgânica, Universidade Federal Fluminense, Niterói 24020-141, Brazil
| | - Miriam S Moraes
- Departamento de Fisiologia, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Myna Nakabashi
- Departamento de Fisiologia, Universidade de São Paulo, São Paulo 05508-900, Brazil
| | - Philip J Rosenthal
- Department of Medicine, University of California, San Francisco, CA 94143, USA
| | - Vitor F Ferreira
- Departamento de Química Orgânica, Universidade Federal Fluminense, Niterói 24020-141, Brazil
| | - Celia RS Garcia
- Departamento de Fisiologia, Universidade de São Paulo, São Paulo 05508-900, Brazil
- Universidade de São Paulo, Instituto de Biociências, Rua do Matão, travessa 14, n.321 Cidade Universitária, CEP 05508-900 São Paulo, SP, Brazil
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Oliveira RAS, Correia-Oliveira J, Tang LJ, Garcia RC. A proteomic insight into the effects of the immunomodulatory hydroxynaphthoquinone lapachol on activated macrophages. Int Immunopharmacol 2012; 14:54-65. [PMID: 22705049 DOI: 10.1016/j.intimp.2012.05.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Revised: 05/29/2012] [Accepted: 05/29/2012] [Indexed: 12/31/2022]
Abstract
We report the effect of an immunomodulatory and anti-mycobacterial naphthoquinone, lapachol, on the bi-dimensional patterns of protein expression of toll-like receptor 2 (TLR2)-agonised and IFN-γ-treated THP-1 macrophages. This non-hypothesis driven proteomic analysis intends to shed light on the cellular functions lapachol may be affecting. Proteins of both cytosol and membrane fractions were analysed. After quantification of the protein spots, the protein levels corresponding to macrophages activated in the absence or presence of lapachol were compared. A number of proteins were identified, the levels of which were appreciably and significantly increased or decreased as a result of the action of lapachol on the activated macrophages: cofilin-1, fascin, plastin-2, glucose-6-P-dehydrogenase, adenylyl cyclase-associated protein 1, pyruvate kinase, sentrin-specific protease 6, cathepsin B, cathepsin D, cytosolic aminopeptidase, proteasome β type-4 protease, tryptophan-tRNA ligase, DnaJ homolog and protein disulphide isomerase. Altogether, the comparative analysis performed indicates that lapachol could be hypothetically causing an impairment of cell migration and/or phagocytic capacity, an increase in NADPH availability, a decrease in pyruvate concentration, protection from proteosomal protein degradation, a decrease in lysosomal protein degradation, an impairment of cytosolic peptide generation, and an interference with NOS2 activation and grp78 function. The present proteomic results suggest issues that should be experimentally addressed ex- and in-vivo, to establish more accurately the potential of lapachol as an anti-infective drug. This study also constitutes a model for the pre-in-vivo evaluation of drug actions.
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Affiliation(s)
- Renato A S Oliveira
- Leukocyte Biology Group, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
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Hughes LM, Lanteri CA, O’Neil MT, Johnson JD, Gribble GW, Trumpower BL. Design of anti-parasitic and anti-fungal hydroxy-naphthoquinones that are less susceptible to drug resistance. Mol Biochem Parasitol 2011; 177:12-9. [PMID: 21251932 PMCID: PMC5054302 DOI: 10.1016/j.molbiopara.2011.01.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 12/23/2010] [Accepted: 01/05/2011] [Indexed: 10/18/2022]
Abstract
Atovaquone is a hydroxy-naphthoquinone that is used to treat parasitic and fungal infections including Plasmodium falciparum (malaria), Pneumocystis jivorecii (pneumonia) and Toxoplasma gondii (toxoplasmosis). It blocks mitochondrial oxidation of ubiquinol in these organisms by binding to the ubiquinol oxidation site of the cytochrome bc(1) complex. Failure of atovaquone treatment has been linked to the appearance of mutations in the mitochondrially encoded gene for cytochrome b. In order to determine the optimal parameters required for inhibition of respiration in parasites and pathogenic fungi and overcome drug resistance, we have synthesized and tested the inhibitory activity of novel hydroxy-naphthoquinones against blood stage P. falciparum and liver stage P. berghei and against cytochrome bc(1) complexes isolated from yeast strains bearing mutations in cytochrome b associated with resistance in Plasmodium, Pneumocystis, and Toxoplasma. One of the new inhibitors is highly effective against an atovaquone resistant Plasmodium and illustrates the type of modification to the hydroxy-naphthoquinone ring of atovaquone that might mitigate drug resistance.
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Affiliation(s)
- Louise M. Hughes
- Department of Biochemistry, Dartmouth Medical School, 7200 Vail, Hanover, NH 03755, USA
| | - Charlotte A. Lanteri
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Michael T. O’Neil
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Jacob D. Johnson
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | | | - Bernard L. Trumpower
- Department of Biochemistry, Dartmouth Medical School, 7200 Vail, Hanover, NH 03755, USA
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10
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Oliveira RAS, Azevedo-Ximenes E, Luzzati R, Garcia RC. The hydroxy-naphthoquinone lapachol arrests mycobacterial growth and immunomodulates host macrophages. Int Immunopharmacol 2010; 10:1463-73. [PMID: 20837170 DOI: 10.1016/j.intimp.2010.08.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 08/25/2010] [Accepted: 08/27/2010] [Indexed: 12/31/2022]
Abstract
The present study reports the anti-mycobacterial activity of 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone (lapachol) as well as its influence on macrophage functions. Lapachol (L) did not induce apoptosis/necrosis of THP-1 macrophages at ≤32 μg/mL. Mycobacterium avium liquid growth was arrested by ≥32 μg/mL and intra-macrophage proliferation by ≥16 μg/mL lapachol. The main immuno-modulatory effects of lapachol observed were an up-regulation of interferon-γ-receptor 1 (IFN-γR1) and major histocompatibility complex class II (MHCII) surface expression, and a marked inhibition of IL-10 secretion. Lapachol did not affect resting, IFN-γ- or toll-like receptor 2 (TLR2)-induced levels of oxygen and nitrogen metabolism key proteins nor the TLR2-mediated secretion of TNF-α, nor induced either oxidative or endoplasmic reticulum (ER) stress. Lapachol inhibited the surface expression of the co-stimulatory molecule CD86 but not that of CD80 and CD83. The results obtained indicate that the substituted naphthoquinone lapachol exhibits an anti-mycobacterial activity that is more efficient intra- than extra-cellularly, and exerts immuno-modulatory effects some of which may enhance the capacity of the host cell to control mycobacterial growth. The immune-modulatory action of lapachol could contribute to its more efficient intra-macrophage anti-mycobacterial activity.
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Affiliation(s)
- Renato A S Oliveira
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
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Zsila F, Fitos I. Combination of chiroptical, absorption and fluorescence spectroscopic methods reveals multiple, hydrophobicity-driven human serum albumin binding of the antimalarial atovaquone and related hydroxynaphthoquinone compounds. Org Biomol Chem 2010; 8:4905-14. [PMID: 20737064 DOI: 10.1039/c0ob00124d] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-affinity human serum albumin (HSA) binding of the C3-substituted antimalarial 2-hydroxy-1,4-naphthoquinone derivative atovaquone (ATQ) has been demonstrated and studied by circular dichroism (CD), UV/VIS absorption, fluorescence spectroscopy and affinity chromatography methods. The analysis of induced CD data generated upon HSA binding of ATQ revealed two high-affinity binding sites (K(a) ≈ 2 × 10(6) M(-1)). CD interaction studies and displacement of specific fluorescent and radioactive marker ligands indicated the contribution of both principal drug binding sites of HSA to complexation of ATQ, and also suggested the possibility of simultaneous binding of ATQ and some other drugs (e.g. warfarin, phenylbutazone, diazepam). Comparison of UV/VIS spectra of ATQ measured in aqueous solutions indicated the prevalence of the anionic species formed by dissociation of the 2-hydroxyl group. HSA binding of related natural hydroxynaphthoquinones, lapachol and lawsone also induces similar CD spectra. The much weaker binding affinity of lawsone (K(a) ≈ 10(4) M(-1)) bearing no C3 substituent highlights the importance of hydrophobic interactions in the strong HSA binding of ATQ and lapachol. Since neither drug exhibited significant binding to serum α(1)-acid glycoprotein, HSA must be the principal plasma protein for the binding and transportation of 2-hydroxy-1,4-naphthoquinone-type compounds which are ionized at physiological pH values.
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Affiliation(s)
- Ferenc Zsila
- Department of Molecular Pharmacology, Institute of Biomolecular Chemistry, Chemical Research Center, H-1025 Budapest, Pusztaszeri út 59-67, Hungary.
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