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Antimalarial activity of the myxobacterial macrolide chlorotonil a. Antimicrob Agents Chemother 2014; 58:6378-84. [PMID: 25114138 DOI: 10.1128/aac.03326-14] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myxobacteria are Gram-negative soil-dwelling bacteria belonging to the phylum Proteobacteria. They are a rich source of promising compounds for clinical application, such as epothilones for cancer therapy and several new antibiotics. In the course of a bioactivity screening program of secondary metabolites produced by Sorangium cellulosum strains, the macrolide chlorotonil A was found to exhibit promising antimalarial activity. Subsequently, we evaluated chlorotonil A against Plasmodium falciparum laboratory strains and clinical isolates from Gabon. Chlorotonil A was highly active, with a 50% inhibitory concentration between 4 and 32 nM; additionally, no correlations between the activities of chlorotonil A and artesunate (rho, 0.208) or chloroquine (rho, -0.046) were observed. Per os treatment of Plasmodium berghei-infected mice with four doses of as little as 36 mg of chlorotonil A per kg of body weight led to the suppression of parasitemia with no obvious signs of toxicity. Chlorotonil A acts against all stages of intraerythrocytic parasite development, including ring-stage parasites and stage IV to V gametocytes, and it requires only a very short exposure to the parasite to exert its antimalarial action. Conclusively, chlorotonil A has an exceptional and unprecedented profile of action and represents an urgently required novel antimalarial chemical scaffold. Therefore, we propose it as a lead structure for further development as an antimalarial chemotherapeutic.
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Stewart LB, Peters W, Robinson BL. The chemotherapy of rodent malaria. LXII. Drug combinations to impede the selection of drug resistance, part 5: rates of development of resistance to some inhibitors of folate metabolism and to artesunate. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2013; 98:763-83. [PMID: 15667710 DOI: 10.1179/136485913x13789813917625] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In recent years infection with chloroquine-resistant Plasmodium falciparum has been combatted with two long-acting antimalarials, pyrimethamine and sulfadoxine, in the combination known as Fansidar that exerts a strong, synergistic action on the asexual stages of the parasite. This second-line regimen, however, is failing increasingly because of the selection of resistant clones in endemic areas, and effective, safe, alternative drugs or drug combinations that are also affordable are urgently needed. Antimalarial drugs with shorter half-lives than those of pyrimethamine or sulfadoxine are likely to be slower to select resistant parasites. In the experiments reported here, the baseline in-vivo responses of rodent malarial parasites to chlorproguanil and proguanil and their active metabolites, chlorcycloguanil and cycloguanil, as well as those to dapsone and artesunate, were explored. In general, the most sensitive parasite to all of these compounds was P. chabaudi. When the drugs were used, individually, to select resistance via the '2%-relapse technique', relatively stable resistance to each was obtained in P. chabaudi as well as in P. berghei and P. yoelii ssp. NS, the last of these being also highly resistant to chloroquine. Of most concern was the rapidity and high level of resistance developed by P. chabaudi to artesunate. The experiments also validated the use of chlorcycloguanil or cycloguanil as surrogates for chlorproguanil or proguanil. Further studies to investigate the possible value of administering chlorproguanil-dapsone, with or without artesunate, are under way and will be reported separately.
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Affiliation(s)
- L B Stewart
- Centre for Tropical Antiprotozoal Chemotherapy, Y Block, Northwick Park Institute for Medical Research, Watford Road, Harrow HA1 3UJ, UK.
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Peters W, Stewart LB, Robinson BL. The chemotherapy of rodent malaria. LXIII. Drug combinations to impede the selection of drug resistance, part 6: the potential value of chlorproguanil and dapsone in combination, and with the addition of artesunate. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2013; 99:457-72. [PMID: 16004705 DOI: 10.1179/136485905x51274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Resistance is readily produced in rodent malaria using the single-dose, '2%-relapse technique' (2%RT) against the individual compounds chlorproguanil (CPG), chlorcycloguanil (CCG), cycloguanil, dapsone (DDS) and artesunate (ASN). Using the '4-day test', a low level of synergism or a simple additional action between CPG and DDS was observed with multiple dosing of these two compounds in a combination. Resistance to a 1 : 3 combination of CPG-DDS was selected in each of three parasite lines: Plasmodium berghei NK65, P. yoelii ssp. NS and P. chabaudi AS. Of these lines, P. chabaudi AS was found to be the most sensitive to the 1 : 3 combination in the 2%RT (and was also previously found to be the most sensitive when the compounds were used individually). Plasmodium chabaudi AS was also the line found most sensitive to a 7 : 21 : 300 combination of CPG-DDS-ASN (CDA). In mice infected with P. chabaudi AS, compared with the use of the individual components, the CPG-DDS combination only a gave a modest level of protection (as indicated by the increase in the time required to select resistance in the 2%RT) but the triple CDA combination was totally effective over the duration of the experiment. New pharmacokinetic data to be reported elsewhere indicate, however, that the antimalarial action of CPG in mice is exerted by a mechanism that is not associated with the drug's conversion to the antifolate triazine, CCG. The question thus arises as to how, in the present model, the protective action of CDA was effected. The present results nevertheless reinforce the hypothesis that a CDA combination, appropriately proportioned for human use, should be of practical value, in protecting the individual components, when used for the treatment of multidrug-resistant P. falciparum, and possibly other Plasmodium species, in endemic areas. Clinical trials, both with a CPG-DDS combination (Lapdap) and CDA, are currently under way in tropical Africa. Further studies are now required to determine whether DDS, CPG or an as-yet unidentified metabolite of CPG interact with ASN, and whether a simple double combination of ASN with one or other of these would be as protective, against the selection of resistance, as CDA.
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Affiliation(s)
- W Peters
- Centre for Tropical Antiprotozoal Chemotherapy, Y Block, Northwick Park Institute for Medical Research, Harrow, UK.
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Dubar F, Egan TJ, Pradines B, Kuter D, Ncokazi KK, Forge D, Paul JF, Pierrot C, Kalamou H, Khalife J, Buisine E, Rogier C, Vezin H, Forfar I, Slomianny C, Trivelli X, Kapishnikov S, Leiserowitz L, Dive D, Biot C. The antimalarial ferroquine: role of the metal and intramolecular hydrogen bond in activity and resistance. ACS Chem Biol 2011; 6:275-87. [PMID: 21162558 DOI: 10.1021/cb100322v] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Inhibition of hemozoin biocrystallization is considered the main mechanism of action of 4-aminoquinoline antimalarials including chloroquine (CQ) but cannot fully explain the activity of ferroquine (FQ) which has been related to redox properties and intramolecular hydrogen bonding. Analogues of FQ, methylferroquine (Me-FQ), ruthenoquine (RQ), and methylruthenoquine (Me-RQ), were prepared. Combination of physicochemical and molecular modeling methods showed that FQ and RQ favor intramolecular hydrogen bonding between the 4-aminoquinoline NH group and the terminal amino group in the absence of water, suggesting that this structure may enhance its passage through the membrane. This was further supported by the use of Me-FQ and Me-RQ where the intramolecular hydrogen bond cannot be formed. Docking studies suggest that FQ can interact specifically with the {0,0,1} and {1,0,0} faces of hemozoin, blocking crystal growth. With respect to the structure-activity relationship, the antimalarial activity on 15 different P. falciparum strains showed that the activity of FQ and RQ were correlated with each other but not with CQ, confirming lack of cross resistance. Conversely, Me-FQ and Me-RQ showed significant cross-resistance with CQ. Mutations or copy number of pfcrt, pfmrp, pfmdr1, pfmdr2, or pfnhe-1 did not exhibit significant correlations with the IC(50) of FQ or RQ. We next showed that FQ and Me-FQ were able to generate hydroxyl radicals, whereas RQ and me-RQ did not. Ultrastructural studies revealed that FQ and Me-FQ but not RQ or Me-RQ break down the parasite digestive vacuole membrane, which could be related to the ability of the former to generate hydroxyl radicals.
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Affiliation(s)
- Faustine Dubar
- Université de Lille1, Unité de Catalyse et Chimie du Solide - UMR CNRS 8181, ENSCL, Bâtiment C7, B.P. 90108, 59652 Villeneuve d’Ascq Cedex, France
- Université de Lille1, Unité de Glycobiologie Structurale et Fonctionnelle, CNRS UMR 8576, IFR 147, 59650 Villeneuve d'Ascq Cédex, France
| | - Timothy J. Egan
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
| | - Bruno Pradines
- Institut de Recherche Biomédicale des Armées, Antenne de Marseille, Unité de Recherche en Biologie et Epidémiologie Parasitaires, URMITE -UMR 6236, Allée du Médecin Colonel Jamot, Parc le Pharo, BP 60109, 13262 Marseille Cedex 07, France
| | - David Kuter
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
| | - Kanyile K. Ncokazi
- Department of Chemistry, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
| | - Delphine Forge
- Laboratoire de chimie organique, Université de Mons, 20 place du parc, 7000 Mons, Belgium
| | - Jean-François Paul
- Université de Lille1, Unité de Catalyse et Chimie du Solide - UMR CNRS 8181, ENSCL, Bâtiment C7, B.P. 90108, 59652 Villeneuve d’Ascq Cedex, France
| | - Christine Pierrot
- CIIL, Inserm U 1019, UMR CNRS 8024 Université Lille Nord de France, Institut Pasteur de Lille, 1 rue du Pr Calmette, 59019 Lille Cedex, France
| | - Hadidjatou Kalamou
- CIIL, Inserm U 1019, UMR CNRS 8024 Université Lille Nord de France, Institut Pasteur de Lille, 1 rue du Pr Calmette, 59019 Lille Cedex, France
| | - Jamal Khalife
- CIIL, Inserm U 1019, UMR CNRS 8024 Université Lille Nord de France, Institut Pasteur de Lille, 1 rue du Pr Calmette, 59019 Lille Cedex, France
| | - Eric Buisine
- Ecole Nationale Supérieure de Chimie de Lille, Bâtiment C7, Avenue Mendeleïev - B.P. 90108, 59652 Villeneuve d’Ascq cedex, France
| | - Christophe Rogier
- Institut de Recherche Biomédicale des Armées, Antenne de Marseille, Unité de Recherche en Biologie et Epidémiologie Parasitaires, URMITE -UMR 6236, Allée du Médecin Colonel Jamot, Parc le Pharo, BP 60109, 13262 Marseille Cedex 07, France
| | - Hervé Vezin
- Université de Lille1, Laboratoire de Spectrochimie Infrarouge et Raman (LASIR), CNRS UMR 8516, Bâtiment C4, 59655 Villeneuve d'Ascq Cedex, France
| | - Isabelle Forfar
- Université de Bordeaux, Pharmacochimie EA 4138, Bordeaux, France
| | - Christian Slomianny
- Université de Lille1, Inserm U1003 - Laboratoire de Physiologie Cellulaire, Bâtiment SN3, 59655 Villeneuve d'Ascq Cédex, France
| | - Xavier Trivelli
- Université de Lille1, Unité de Glycobiologie Structurale et Fonctionnelle, CNRS UMR 8576, IFR 147, 59650 Villeneuve d'Ascq Cédex, France
| | - Sergey Kapishnikov
- Department of Materials and Interfaces, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Leslie Leiserowitz
- Department of Materials and Interfaces, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Daniel Dive
- CIIL, Inserm U 1019, UMR CNRS 8024 Université Lille Nord de France, Institut Pasteur de Lille, 1 rue du Pr Calmette, 59019 Lille Cedex, France
| | - Christophe Biot
- Université de Lille1, Unité de Catalyse et Chimie du Solide - UMR CNRS 8181, ENSCL, Bâtiment C7, B.P. 90108, 59652 Villeneuve d’Ascq Cedex, France
- Université de Lille1, Unité de Glycobiologie Structurale et Fonctionnelle, CNRS UMR 8576, IFR 147, 59650 Villeneuve d'Ascq Cédex, France
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Gligorijevic B, Purdy K, Elliott DA, Cooper RA, Roepe PD. Stage independent chloroquine resistance and chloroquine toxicity revealed via spinning disk confocal microscopy. Mol Biochem Parasitol 2008; 159:7-23. [PMID: 18281110 DOI: 10.1016/j.molbiopara.2007.12.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 12/14/2007] [Accepted: 12/19/2007] [Indexed: 10/22/2022]
Abstract
We previously customized a Nipkow spinning disk confocal microscope (SDCM) to acquire 4D data for live, intraerythrocytic malarial parasites [Gligorijevic B, McAllister R, Urbach JS, Roepe, PD. Spinning disk confocal microscopy of live, intraerythrocytic malarial parasites. 1. Quantification of hemozoin development for drug sensitive versus resistant malaria. Biochemistry 2006;45:12400-10]. We reported that chloroquine (CQ) treatment did not appear to affect progress through the cell cycle, and suggested that toxicity may be manifested post-schizogony. We now use SDCM, synchronized cell culture and continuous vs. bolus drug dosing to investigate stage specific CQ effects in detail. We develop a novel, extremely rapid method for counting schizont nuclei in 3D. We then quantify schizont nuclei and hemozoin (Hz) production for live parasite cultures pulsed with CQ at different stages in the cell cycle and find that bolus treatment of rings affects the multiplicity of nuclear division. We quantify parasitemia and merozoite development in subsequent cycles following bolus CQ exposure and find that a portion of CQ toxicity is manifested post-schizogony as "delayed death". Using these methods and others we compare CQ sensitive (CQS) vs. resistant (CQR) strains as well as transfectants that are CQR via introduction of mutant PfCRT. Surprisingly, we find that PfCRT confers resistance to CQ administered at the very early ring stage of development, wherein a digestive vacuole is not yet formed, as well as at the schizont stage, wherein Hz production is thought to plateau. Taken together, these data force a rethinking of CQ pharmacology and the mechanism of CQR.
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Affiliation(s)
- Bojana Gligorijevic
- Department of Chemistry and Center for Infectious Diseases, Georgetown University, 37th and O Streets, Washington, DC 20057, USA
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Peters W, Porter M. The chemotherapy of rodent malaria, XXVI. The potential value of WR 122,455 (a 9-phenanthrenemethanol) against drug-resistant malaria parasites. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 1976; 70:271-81. [PMID: 788658 DOI: 10.1080/00034983.1976.11687123] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The phenanthrenemethanol compound WR 122,455 is an effective blood schizontocide against lines of Plasmodium berghei that are highly resistant to primaquine, sulphonamides, pyrimethamine and cycloguanil. It is also active against the NS line that is moderately resistant to chloroquine. WR 122,455 is inactive against the RC line which is highly resistant to chloroquine. Resistance to WR 122,455 is fairly readily developed by the drug-sensitive N strain of P. berghei, using a relapse technique. Resistance develops very readily to the NS line of P. berghei. Both resistant lines exhibit cross-resistance to quinine, but a roughly normal response to chloroquine, primaquine, sulphonamides, dapsone, pyrimethamine and cycloguanil. Resistance to WR 122,455 is stable through cyclical transmission and through cryopreservation, as well as in the absence of drug selection pressure. The resistant parasites have an essentially normal morphology and virulence. A warning is given against the widescale use of WR 122,455 or similar new drugs for human malaria other than in a suitable combination, in order to minimize the danger of the development of resistance to them.
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