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Nguyen W, Dans MG, Ngo A, Gancheva MR, Romeo O, Duffy S, de Koning-Ward TF, Lowes KN, Sabroux HJ, Avery VM, Wilson DW, Gilson PR, Sleebs BE. Structure activity refinement of phenylsulfonyl piperazines as antimalarials that block erythrocytic invasion. Eur J Med Chem 2021; 214:113253. [PMID: 33610028 DOI: 10.1016/j.ejmech.2021.113253] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/12/2021] [Accepted: 01/29/2021] [Indexed: 12/19/2022]
Abstract
The emerging resistance to combination therapies comprised of artemisinin derivatives has driven a need to identify new antimalarials with novel mechanisms of action. Central to the survival and proliferation of the malaria parasite is the invasion of red blood cells by Plasmodium merozoites, providing an attractive target for novel therapeutics. A screen of the Medicines for Malaria Venture Pathogen Box employing transgenic P. falciparum parasites expressing the nanoluciferase bioluminescent reporter identified the phenylsulfonyl piperazine class as a specific inhibitor of erythrocyte invasion. Here, we describe the optimization and further characterization of the phenylsulfonyl piperazine class. During the optimization process we defined the functionality required for P. falciparum asexual stage activity and determined the alpha-carbonyl S-methyl isomer was important for antimalarial potency. The optimized compounds also possessed comparable activity against multidrug resistant strains of P. falciparum and displayed weak activity against sexual stage gametocytes. We determined that the optimized compounds blocked erythrocyte invasion consistent with the asexual activity observed and therefore the phenylsulfonyl piperazine analogues described could serve as useful tools for studying Plasmodium erythrocyte invasion.
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Affiliation(s)
- William Nguyen
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Madeline G Dans
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, 3004, Australia; School of Medicine, Deakin University, Waurn Ponds, 3216, Australia
| | - Anna Ngo
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Maria R Gancheva
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Ornella Romeo
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Sandra Duffy
- Discovery Biology, Griffith University, Nathan, Queensland, 4111, Australia
| | | | - Kym N Lowes
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Helene Jousset Sabroux
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Vicky M Avery
- Discovery Biology, Griffith University, Nathan, Queensland, 4111, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, Australia; Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, 3004, Australia
| | - Paul R Gilson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, 3004, Australia
| | - Brad E Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia.
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Burns AL, Sleebs BE, Siddiqui G, De Paoli AE, Anderson D, Liffner B, Harvey R, Beeson JG, Creek DJ, Goodman CD, McFadden GI, Wilson DW. Retargeting azithromycin analogues to have dual-modality antimalarial activity. BMC Biol 2020; 18:133. [PMID: 32993629 PMCID: PMC7526119 DOI: 10.1186/s12915-020-00859-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/28/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Resistance to front-line antimalarials (artemisinin combination therapies) is spreading, and development of new drug treatment strategies to rapidly kill Plasmodium spp. malaria parasites is urgently needed. Azithromycin is a clinically used macrolide antibiotic proposed as a partner drug for combination therapy in malaria, which has also been tested as monotherapy. However, its slow-killing 'delayed-death' activity against the parasite's apicoplast organelle and suboptimal activity as monotherapy limit its application as a potential malaria treatment. Here, we explore a panel of azithromycin analogues and demonstrate that chemical modifications can be used to greatly improve the speed and potency of antimalarial action. RESULTS Investigation of 84 azithromycin analogues revealed nanomolar quick-killing potency directed against the very earliest stage of parasite development within red blood cells. Indeed, the best analogue exhibited 1600-fold higher potency than azithromycin with less than 48 hrs treatment in vitro. Analogues were effective against zoonotic Plasmodium knowlesi malaria parasites and against both multi-drug and artemisinin-resistant Plasmodium falciparum lines. Metabolomic profiles of azithromycin analogue-treated parasites suggested activity in the parasite food vacuole and mitochondria were disrupted. Moreover, unlike the food vacuole-targeting drug chloroquine, azithromycin and analogues were active across blood-stage development, including merozoite invasion, suggesting that these macrolides have a multi-factorial mechanism of quick-killing activity. The positioning of functional groups added to azithromycin and its quick-killing analogues altered their activity against bacterial-like ribosomes but had minimal change on 'quick-killing' activity. Apicoplast minus parasites remained susceptible to both azithromycin and its analogues, further demonstrating that quick-killing is independent of apicoplast-targeting, delayed-death activity. CONCLUSION We show that azithromycin and analogues can rapidly kill malaria parasite asexual blood stages via a fast action mechanism. Development of azithromycin and analogues as antimalarials offers the possibility of targeting parasites through both a quick-killing and delayed-death mechanism of action in a single, multifactorial chemotype.
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Affiliation(s)
- Amy L Burns
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, Australia
| | - Brad E Sleebs
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, 3050, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, 3050, Australia
| | - Ghizal Siddiqui
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, 3052, Australia
| | - Amanda E De Paoli
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, 3052, Australia
| | - Dovile Anderson
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, 3052, Australia
| | - Benjamin Liffner
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, Australia
| | - Richard Harvey
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, Victoria, 3004, Australia
- Department of Medicine, University of Melbourne, Melbourne, Australia
- Central Clinical School and Department of Microbiology, Monash University, Melbourne, Australia
| | - Darren J Creek
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, 3052, Australia
| | - Christopher D Goodman
- School of Biosciences, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Geoffrey I McFadden
- School of Biosciences, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, 5005, Australia.
- Burnet Institute, Melbourne, Victoria, 3004, Australia.
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Ressurreição M, Thomas JA, Nofal SD, Flueck C, Moon RW, Baker DA, van Ooij C. Use of a highly specific kinase inhibitor for rapid, simple and precise synchronization of Plasmodium falciparum and Plasmodium knowlesi asexual blood-stage parasites. PLoS One 2020; 15:e0235798. [PMID: 32673324 PMCID: PMC7365400 DOI: 10.1371/journal.pone.0235798] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/22/2020] [Indexed: 12/15/2022] Open
Abstract
During the course of the asexual erythrocytic stage of development, Plasmodium spp. parasites undergo a series of morphological changes and induce alterations in the host cell. At the end of this stage, the parasites egress from the infected cell, after which the progeny invade a new host cell. These processes are rapid and occur in a time-dependent manner. Of particular importance, egress and invasion of erythrocytes by the parasite are difficult to capture in an unsynchronized culture, or even a culture that has been synchronized within a window of one to several hours. Therefore, precise synchronization of parasite cultures is of paramount importance for the investigation of these processes. Here we describe a method for synchronizing Plasmodium falciparum and Plasmodium knowlesi asexual blood stage parasites with ML10, a highly specific inhibitor of the cGMP-dependent protein kinase (PKG) that arrests parasite growth approximately 15 minutes prior to egress. This inhibitor allows parasite cultures to be synchronized so that all parasites are within a window of development of several minutes, with a simple wash step. Furthermore, we show that parasites remain viable for several hours after becoming arrested by the compound and that ML10 has advantages, owing to its high specificity and low EC50, over the previously used PKG inhibitor Compound 2. Here, we demonstrate that ML10 is an invaluable tool for the study of Plasmodium spp. asexual blood stage biology and for the routine synchronization of P. falciparum and P. knowlesi cultures.
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Affiliation(s)
- Margarida Ressurreição
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - James A. Thomas
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Stephanie D. Nofal
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christian Flueck
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Robert W. Moon
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - David A. Baker
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Christiaan van Ooij
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Cheo SW, Khoo TT, Tan YA, Yeoh WC, Low QJ. A case of severe Plasmodium knowlesi malaria in a post-splenectomy patient. Med J Malaysia 2020; 75:447-449. [PMID: 32724015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Malaria is a parasitic disease that is caused by the Plasmodium parasite. Worldwide, it remains a significant public health problem especially in the Africa region where it contributes to more than 90% of cases and malaria death. However, zoonotic (simian) Plasmodium knowlesi parasite is a widely prevalent cause of malaria in the South East Asian countries. It is known to cause severe human disease due to its 24hour erythrocytic cycles. Thus far, cases of severe falciparum malaria have been reported in asplenic patients. Here, we report a case of severe P.knowlesi malaria in a 51-year-old man who is a postsplenectomy patient.
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Affiliation(s)
- S W Cheo
- Hospital Lahad Datu, Department of Internal Medicine, Sabah, Malaysia.
| | - T T Khoo
- Hospital Queen Elizabeth, Department of Internal Medicine, Sabah, Malaysia
| | - Y A Tan
- Hospital Queen Elizabeth, Department of Internal Medicine, Sabah, Malaysia
| | - W C Yeoh
- Hospital Queen Elizabeth, Department of Internal Medicine, Sabah, Malaysia
| | - Q J Low
- Hospital Sultanah Nora Ismail, Department of Internal Medicine, Johor, Malaysia
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Verzier LH, Coyle R, Singh S, Sanderson T, Rayner JC. Plasmodium knowlesi as a model system for characterising Plasmodium vivax drug resistance candidate genes. PLoS Negl Trop Dis 2019; 13:e0007470. [PMID: 31158222 PMCID: PMC6564043 DOI: 10.1371/journal.pntd.0007470] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 06/13/2019] [Accepted: 05/15/2019] [Indexed: 12/29/2022] Open
Abstract
Plasmodium vivax causes the majority of malaria outside Africa, but is poorly understood at a cellular level partly due to technical difficulties in maintaining it in in vitro culture conditions. In the past decades, drug resistant P. vivax parasites have emerged, mainly in Southeast Asia, but while some molecular markers of resistance have been identified, none have so far been confirmed experimentally, which limits interpretation of the markers, and hence our ability to monitor and control the spread of resistance. Some of these potential markers have been identified through P. vivax genome-wide population genetic analyses, which highlighted genes under recent evolutionary selection in Southeast Asia, where chloroquine resistance is most prevalent. These genes could be involved in drug resistance, but no experimental proof currently exists to support this hypothesis. In this study, we used Plasmodium knowlesi, the most closely related species to P. vivax that can be cultured in human erythrocytes, as a model system to express P. vivax genes and test for their role in drug resistance. We adopted a strategy of episomal expression, and were able to express fourteen P. vivax genes, including two allelic variants of several hypothetical resistance genes. Their expression level and localisation were assessed, confirming cellular locations conjectured from orthologous species, and suggesting locations for several previously unlocalised proteins, including an apical location for PVX_101445. These findings establish P. knowlesi as a suitable model for P. vivax protein expression. We performed chloroquine and mefloquine drug assays, finding no significant differences in drug sensitivity: these results could be due to technical issues, or could indicate that these genes are not actually involved in drug resistance, despite being under positive selection pressure in Southeast Asia. These data confirm that in vitro P. knowlesi is a useful tool for studying P. vivax biology. Its close evolutionary relationship to P. vivax, high transfection efficiency, and the availability of markers for colocalisation, all make it a powerful model system. Our study is the first of its kind using P. knowlesi to study unknown P. vivax proteins and investigate drug resistance mechanisms.
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Affiliation(s)
- Lisa H. Verzier
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Rachael Coyle
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Shivani Singh
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Theo Sanderson
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
| | - Julian C. Rayner
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, United Kingdom
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Abstract
Important strides have been made within the past decade toward malaria elimination in many regions, and with this progress, the feasibility of eradication is once again under discussion. If the ambitious goal of eradication is to be achieved by 2040, all species of Plasmodium infecting humans will need to be targeted with evidence-based and concerted interventions. In this perspective, the potential barriers to achieving global malaria elimination are discussed with respect to the related diversities in host, parasite, and vector populations. We argue that control strategies need to be reorientated from a sequential attack on each species, dominated by Plasmodium falciparum to one that targets all species in parallel. A set of research themes is proposed to mitigate the potential setbacks on the pathway to a malaria-free world.
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Affiliation(s)
- Andrew A. Lover
- Malaria Elimination Initiative at the University of California, San Francisco, San Francisco, California
| | - J. Kevin Baird
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute of Molecular Biology, Jakarta, Indonesia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Roly Gosling
- Malaria Elimination Initiative at the University of California, San Francisco, San Francisco, California
| | - Ric N. Price
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
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Grigg MJ, Barber BE, Marfurt J, Imwong M, William T, Bird E, Piera KA, Aziz A, Boonyuen U, Drakeley CJ, Cox J, White NJ, Cheng Q, Yeo TW, Auburn S, Anstey NM. Dihydrofolate-Reductase Mutations in Plasmodium knowlesi Appear Unrelated to Selective Drug Pressure from Putative Human-To-Human Transmission in Sabah, Malaysia. PLoS One 2016; 11:e0149519. [PMID: 26930493 PMCID: PMC4773021 DOI: 10.1371/journal.pone.0149519] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 02/02/2016] [Indexed: 12/22/2022] Open
Abstract
Background Malaria caused by zoonotic Plasmodium knowlesi is an emerging threat in Eastern Malaysia. Despite demonstrated vector competency, it is unknown whether human-to-human (H-H) transmission is occurring naturally. We sought evidence of drug selection pressure from the antimalarial sulfadoxine-pyrimethamine (SP) as a potential marker of H-H transmission. Methods The P. knowlesi dihdyrofolate-reductase (pkdhfr) gene was sequenced from 449 P. knowlesi malaria cases from Sabah (Malaysian Borneo) and genotypes evaluated for association with clinical and epidemiological factors. Homology modelling using the pvdhfr template was used to assess the effect of pkdhfr mutations on the pyrimethamine binding pocket. Results Fourteen non-synonymous mutations were detected, with the most common being at codon T91P (10.2%) and R34L (10.0%), resulting in 21 different genotypes, including the wild-type, 14 single mutants, and six double mutants. One third of the P. knowlesi infections were with pkdhfr mutants; 145 (32%) patients had single mutants and 14 (3%) had double-mutants. In contrast, among the 47 P. falciparum isolates sequenced, three pfdhfr genotypes were found, with the double mutant 108N+59R being fixed and the triple mutants 108N+59R+51I and 108N+59R+164L occurring with frequencies of 4% and 8%, respectively. Two non-random spatio-temporal clusters were identified with pkdhfr genotypes. There was no association between pkdhfr mutations and hyperparasitaemia or malaria severity, both hypothesized to be indicators of H-H transmission. The orthologous loci associated with resistance in P. falciparum were not mutated in pkdhfr. Subsequent homology modelling of pkdhfr revealed gene loci 13, 53, 120, and 173 as being critical for pyrimethamine binding, however, there were no mutations at these sites among the 449 P. knowlesi isolates. Conclusion Although moderate diversity was observed in pkdhfr in Sabah, there was no evidence this reflected selective antifolate drug pressure in humans.
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Affiliation(s)
- Matthew J. Grigg
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
- * E-mail:
| | - Bridget E. Barber
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Jutta Marfurt
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
- Clinical Research Centre, Queen Elizabeth Hospital, Sabah, Malaysia
- Jesselton Medical Centre, Kota Kinabalu, Sabah, Malaysia
| | - Elspeth Bird
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Kim A. Piera
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Ammar Aziz
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Usa Boonyuen
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Christopher J. Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jonathan Cox
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Nicholas J. White
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Qin Cheng
- Australian Army Malaria Institute, Brisbane, Australia
- Clinical Tropical Medicine, Queensland Institute of Medical Research, Brisbane, Australia
| | - Tsin W. Yeo
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Sarah Auburn
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Nicholas M. Anstey
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
- Royal Darwin Hospital, Darwin, Northern Territory, Australia
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Machado-Alba JE. Malaria by Plasmodium knowlesi, A Zoonosis Transmitted by Vectors. Recent Pat Antiinfect Drug Discov 2015; 10:8-9. [PMID: 25851255 DOI: 10.2174/1574891x10666150408155455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Jorge E Machado-Alba
- Grupo de Investigacion en Farmacoepidemiologia y Farmacovigilancia, Faculty of Health Sciences, Universidad Tecnologica de Pereira-Audifarma S.A. Pereira, Risaralda, Colombia.
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Srinivasan V, Mohamed M, Zakaria R, Ahmad AH. Malaria, anti malarial drugs and the role of melatonin. Infect Disord Drug Targets 2012; 12:371-379. [PMID: 23082960 DOI: 10.2174/187152612804142198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 08/27/2012] [Accepted: 08/27/2012] [Indexed: 06/01/2023]
Abstract
Malaria, one of the most deadly diseases of our time affects more than 200 million people across the globe and is responsible for about one million deaths annually. Until recently Plasmodium falciparum has been the main cause for malarial infection in human beings but now Plasmodium knowlesi from Malaysia remains as one of the most virulent parasite spreading fast not only in Malaysia but in different parts of the world. Hence there is urgent need for the global fight to control malaria. Global malaria eradication program by use of insecticide spraying has resulted in good response in the past. Treatment of malaria infected patients with anti-malarial drugs has helped to eliminate malarial infections successfully but with increased resistance displayed by malarial parasites to these drugs there is resurgence of malaria caused both by drug resistance as well as by infection caused by new malarial species like Plasmodium knowlesi. With recent advances on molecular studies on malarial parasites it is now clear that the pineal hormone melatonin acts as a cue for growth and development of Plasmodium falciparum. Same may be true for Plasmodium knowlesi also. Hence treatment modalities that can effectively block the action of melatonin on Plasmodium species during night time by way of using either bright light therapy or use of melatonin receptor blocking can be considered as useful approaches for eliminating malarial infection in man.
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Affiliation(s)
- Venkataramanujam Srinivasan
- Sri Sathya Sai Medical Educational and Research Foundation Medical Sciences Research Study Center, Prasanthi Nilayam, 40-Kovai Thirunagar, 641014, Tamilnadu, India.
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William T, Menon J, Rajahram G, Chan L, Ma G, Donaldson S, Khoo S, Frederick C, Jelip J, Anstey NM, Yeo TW. Severe Plasmodium knowlesi malaria in a tertiary care hospital, Sabah, Malaysia. Emerg Infect Dis 2011. [PMID: 21762579 PMCID: PMC3381373 DOI: 10.3201/eid.1707.101017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The simian parasite Plasmodium knowlesi causes severe human malaria; the optimal treatment remains unknown. We describe the clinical features, disease spectrum, and response to antimalarial chemotherapy, including artemether-lumefantrine and artesunate, in patients with P. knowlesi malaria diagnosed by PCR during December 2007-November 2009 at a tertiary care hospital in Sabah, Malaysia. Fifty-six patients had PCR-confirmed P. knowlesi monoinfection and clinical records available for review. Twenty-two (39%) had severe malaria; of these, 6 (27%) died. Thirteen (59%) had respiratory distress; 12 (55%), acute renal failure; and 12, shock. None experienced coma. Patients with uncomplicated disease received chloroquine, quinine, or artemether-lumefantrine, and those with severe disease received intravenous quinine or artesunate. Parasite clearance times were 1-2 days shorter with either artemether-lumefantrine or artesunate treatment. P. knowlesi is a major cause of severe and fatal malaria in Sabah. Artemisinin derivatives rapidly clear parasitemia and are efficacious in treating uncomplicated and severe knowlesi malaria.
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Affiliation(s)
- Timothy William
- Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysian Borneo
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Were PS, Kinyanjui P, Gicheru MM, Mwangi E, Ozwara HS. Prophylactic and curative activities of extracts from Warburgia ugandensis Sprague (Canellaceae) and Zanthoxylum usambarense (Engl.) Kokwaro (Rutaceae) against Plasmodium knowlesi and Plasmodium berghei. J Ethnopharmacol 2010; 130:158-162. [PMID: 20435133 DOI: 10.1016/j.jep.2010.04.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 04/09/2010] [Accepted: 04/20/2010] [Indexed: 05/29/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE This work reports the anti-plasmodial activities of Warburgia ugandensis and Zanthoxylum usambarense commonly used as phytomedicines against malaria by some Kenyan communities. AIM OF STUDY To determine the anti-plasmodial activities of extracts from Warburgia ugandensis and Zanthoxylum usambarense against Plasmodium knowlesi and Plasmodium berghei. MATERIALS AND METHODS Eight plant extracts were screened for in vitro anti-plasmodial activity against Plasmodium knowlesi, in a 96-well plate incubated at 37 degrees C on a RPMI culture medium supplemented with baboon serum. Of the eight, three were investigated for prophylactic and curative activities in BALB/c mice against drug-sensitive Plasmodium berghei in a 4-day test at a dose rate of 200mg/kg/day. RESULTS Inhibitory concentrations (IC(50)) values of between 3.14 and 75 microg/ml, up to 69% chemosuppression of parasites growth and over 80% survivorship of treated mice were observed. CONCLUSION The two medicinal plants, Warburgia ugandensis and Zanthoxylum usambarense possess bioactive compounds against malaria parasites and could be exploited for further development into malaria therapy.
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Affiliation(s)
- P S Were
- Department of Tropical and Infectious Diseases, Institute of Primate Research, National Museums of Kenya, P.O. Box 24481, Karen, Nairobi, Kenya
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Wang JY, Ding DB, Li GF, Zhao JH. [Therapeutic efficacy of naphthoquine phosphate combined with artemisinine against Plasmodium knowlesi]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2008; 26:442-444. [PMID: 19288919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
OBJECTIVE To study the antimalarial activity of naphthoquine phosphate combined with artemisinine against Plasmodium knowlesi in rhesus monkey. METHODS Monkeys were randomly divided into 9 groups (3/group). The monkeys in groups A and B were treated i.g. once daily for 3 days with 6 or 10 mg/kg of naphthoquine phosphate respectively. Those in groups C and D were treated i.g. twice for the 1st day and once for the 2nd and 3rd day with 31.6 or 100 mg/kg of artemisinine respectively. In groups E, F and G, they were treated i.g. only once with the combination of naphthoquine phosphate 10 mg/kg and artemisinine 10, 20 or 25 mg/kg respectively. Groups H and I served as controls which were treated i.g. only once with 10 mg/kg of naphthoquine phosphate and 30 mg/kg of artemisinine respectively. Parasitemia was examined beginning 24 h after drug administration. The observation lasted 105 days when no more parasite was found. RESULTS At 24 h after drug administration, the parasite reduction rate in all groups was higher than 90%. The parasite clearance time for groups E, F and G was (56.0 +/- 16.0), (53.3 +/- 4.6), and (56.0 +/- 8.0) h respectively, more rapid than that of Group H [(69.3 +/- 4.6) h]. There were 1, 3, 3, 2, 2, and 3 monkeys in groups A, B, D, E, F, and G respectively which were cured. No monkeys were cured in groups C, H and I. CONCLUSION The combination of naphthoquine phosphate and artemisinine is superior to the single component and the optimum proportion in the combination is 1 : 2.5 in treating P. knowlesi infection in monkeys.
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Affiliation(s)
- Jing-yan Wang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing 100071, China
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McCormick GJ, Canfield CJ, Willet GP. In vitro antimalarial activity of nucleic acid precursor analogues in the simian malaria Plasmodium knowlesi. Antimicrob Agents Chemother 2005; 6:16-21. [PMID: 15828165 PMCID: PMC429041 DOI: 10.1128/aac.6.1.16] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Analogues of nucleic acid precursors were screened for antimalarial activity in Plasmodium knowlesi by using an in vitro culture system. Activity was assessed by the degree of inhibition of incorporation of l-[methyl-(14)C]methionine into protein and of [8-(14)C]adenosine and [6-(14)C]orotic acid into ribonucleic acid and deoxyribonucleic acid. The incorporation of adenosine or orotic acid was effectively inhibited by many of the compounds, including 3' analogues of purine nucleosides, many of the 6-position analogues of purine bases and nucleosides, and 5-position analogues of orotic acid. Only a few compounds inhibited methionine incorporation into protein, and in each instance adenosine or orotic acid incorporation also was inhibited. Some compounds inhibited adenosine or orotic acid incorporation into both ribonucleic acid and deoxyribonucleic, whereas other analogues inhibited incorporation into one nucleic acid only. The qualitative and quantitative differences suggest that this experimental system may be appropriate for investigation of metabolic pathways of the malaria parasite, as well as for demonstration of antimalarial activity of candidate antimalaria drugs.
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Wel AVD, Kocken CHM, Pronk TC, Franke-Fayard B, Thomas AW. New selectable markers and single crossover integration for the highly versatile Plasmodium knowlesi transfection system. Mol Biochem Parasitol 2004; 134:97-104. [PMID: 14747147 DOI: 10.1016/j.molbiopara.2003.10.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Plasmodium knowlesi provides a highly versatile transfection system for malaria, since it enables rapid genetic modification of the parasite both in vivo as well as in vitro. However, it is not possible to perform multiple genetic manipulations within one parasite line because of a lack of selectable markers. In an effort to develop additional selectable markers for this parasite, positive and negative selectable markers that have recently been successfully used in Plasmodium falciparum were tested. It was shown that the positive selectable markers human dihydrofolate reductase (hdhfr), blasticidin S deaminase (bsd) and neomycin phosphotransferase II (neo) all conferred drug resistance to P. knowlesi when introduced as episomes. The plasmid containing the hdhfr selectable marker was not only successfully introduced as circular form, but also as linear fragment, demonstrating for the first time single crossover integration in P. knowlesi. Thymidine kinase was tested for its potential as negative selectable marker and it was shown that recombinant P. knowlesi parasites expressing thymidine kinase from episomes were highly sensitive to ganciclovir compared to wild-type P. knowlesi. The availability of new positive selectable markers and a strong candidate for a negative selectable marker for P. knowlesi, in combination with the opportunity to perform targeted single crossover integration in P. knowlesi, significantly increases the flexibility of this transfection system, making it one of the most versatile systems available for Plasmodium.
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Affiliation(s)
- Annemarie v d Wel
- Department of Parasitology, Biomedical Primate Research Centre, P.O. Box 3306, 2280 GH, Rijswijk, The Netherlands
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Li Y, Yang ZS, Zhang H, Cao BJ, Wang FD, Zhang Y, Shi YL, Yang JD, Wu BA. Artemisinin derivatives bearing Mannich base group: synthesis and antimalarial activity. Bioorg Med Chem 2003; 11:4363-8. [PMID: 13129573 DOI: 10.1016/s0968-0896(03)00499-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Novel artemisinin derivatives bearing Mannich base group were prepared and tested for their antimalarial activity. These water-soluble artemisinin derivatives were more stable than sodium artesunate and few compounds were found to be more active against Plasmodium berghei in mice than artesunic acid by oral administration. Two most potent derivatives 17b and 17d were examined for their antimalarial activity against Plasmodium knowlesi in rhesus monkeys.
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Affiliation(s)
- Ying Li
- Department of Synthetic Chemistry, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, China.
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17
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Srinivas SD, Puri SK. Time course of in vitro maturation of intra-erythrocytic malaria parasite: a comparison between Plasmodium falciparum and Plasmodium knowlesi. Mem Inst Oswaldo Cruz 2002; 97:901-3. [PMID: 12386719 DOI: 10.1590/s0074-02762002000600028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The schizont maturation assay for in vitro drug sensitivity tests has been a standard method employed in the global baseline assessment and monitoring of drug response in Plasmodium falciparum. This test is limited in its application to synchronous plasmodial infections because it evaluates the effect of drug on the maturation of parasite especially from ring to schizont stage and therefore synchronized P. falciparum cultures are required. On the other hand, P. knowlesi, a simian malaria parasite has a unique 24-h periodicity and maintains high natural synchronicity in monkeys. The present report presents the results of a comparative study on the course of in vitro maturation of sorbitol synchronized P. falciparum and naturally synchronous P. knowlesi. Ring stage parasites were incubated in RPMI medium supplemented with 10-15% pooled homologous serum in flat-bottomed 96-well micro plates using a candle jar at 37 degrees C. The results suggest that the ideal time for harvesting the micro-assay plates for in vitro drug sensitivity test for sorbitol-synchronized P. falciparum and naturally synchronous P. knowlesi are from 26 to 30 h and from 22 to 25 h, respectively. The advantages of using P. knowlesi in chemotherapeutic studies are discussed.
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Affiliation(s)
- S D Srinivas
- Division of Parasitology, Central Drug Research Institute, Lucknow, India.
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18
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Abstract
Glutathione-S-transferase (GST) activity has been detected in rodent (Plasmodium berghei, P. yoelii), simian (P. knowlesi) and human (P. falciparum) malarial parasites, and in different intraerythrocytic stages of P. knowlesi (schizont > ring > trophozoite). In chloroquine-resistant strains of rodent and human malarial parasites GST activity significantly increases compared to sensitive strains. Further, the increase in enzyme activity is directly related to drug pressure of resistant P. berghei. Complete inhibition of chloroquine-sensitive and resistant P. berghei glutathione-S-transferase activities was observed at 2.5 and 5. micrometer concentration of hemin, respectively. An inverse relationship was found between the heme level and enzyme activity of chloroquine-resistant and sensitive P. berghei. Chloroquine, artemisinin, and primaquine noticeably inhibited GST activity in P. knowlesi.
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Affiliation(s)
- P Srivastava
- Division of Biochemistry, Central Drug Research Institute, Lucknow, India. root%
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Abstract
Intraerythrocytic stages of cell-free Plasmodium knowlesi possess significant activities of heme biosynthetic enzymes, viz. delta-aminolevulinic acid synthase (delta-ALAS), delta-aminolevulinic acid dehydrase (delta-ALAD), ferrochelatase (FC), and tryptophan pyrrolase (enzyme representing free heme pool). delta-Aminolevulinic acid synthase and FC showed higher activities in schizont than in ring trophozoite stage. Uninfected monkey erythrocytes did not possess the above-mentioned enzyme activities; on the contrary, leucocytes showed detectable enzyme activities. delta-Aminolevulinic acid synthase was not appreciably inhibited by different antimalarials. Succinyl acetone and hemin exhibited a concentration-dependent inhibition of delta-ALAD and delta-ALAS, respectively.
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Affiliation(s)
- P Srivastava
- Division of Biochemistry, Central Drug Research Institute, Lucknow, India
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Hesselgesser J, Chitnis CE, Miller LH, Yansura DG, Simmons LC, Fairbrother WJ, Kotts C, Wirth C, Gillece-Castro BL, Horuk R. A mutant of melanoma growth stimulating activity does not activate neutrophils but blocks erythrocyte invasion by malaria. J Biol Chem 1995; 270:11472-6. [PMID: 7744785 DOI: 10.1074/jbc.270.19.11472] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Alanine scanning mutagenesis of the charged amino acids of melanoma growth stimulating activity (MGSA) was used to identify specific residues that are involved in binding to the human erythrocyte Duffy antigen/chemokine receptor (DARC) and to the type B interleukin-8 receptor (IL-8RB) on neutrophils. Receptor binding and biological studies with the alanine scan mutants of MGSA demonstrate that MGSA binds to DARC and the IL-8RB through distinct binding regions. One of the MGSA mutants, E6A, binds to human erythrocytes and is able to inhibit malaria invasion as efficiently as wild type MGSA but has a severely reduced ability to bind to or signal through the IL-8RB. Mutant chemokines like E6A could prove to be useful therapeutically for the design of receptor blocking drugs that inhibit erythrocyte invasion by Plasmodium vivax malaria.
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Affiliation(s)
- J Hesselgesser
- Genentech, Inc., South San Francisco, California 94080, USA
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Abstract
Staurosporine, a protein kinase inhibitor, inhibits the invasion of rhesus by Plasmodium knowlesi merozoites with an IC50 of 250 nM. The drug exerts its effects primarily on the merozoite, with little or no effect on the erythrocyte. Okadaic acid, an inhibitor of protein phosphatases, can partially abrogate the inhibitory effects of staurosporine. Staurosporine arrests invasion at a step which is ultrastructurally similar to the arrest caused by cytochalasins B and D: the merozoite attaches, apically reorients, and forms a junction with the erythrocyte, but it does not internalize. These results suggest that protein phosphorylation within the merozoite plays an important role in the internalization step of invasion.
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Affiliation(s)
- G E Ward
- Laboratory of Malaria Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
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Srivastava P, Puri SK, Dutta GP, Pandey VC. Status of oxidative stress and antioxidant defences during Plasmodium knowlesi infection and chloroquine treatment in Macaca mulatta. Int J Parasitol 1992; 22:243-5. [PMID: 1316884 DOI: 10.1016/0020-7519(92)90109-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Plasmodium knowlesi (a simian malarial parasite) infection resulted in elevation of hepatic oxidative stress in monkeys. Further, the antioxidant defence system of the host was also noticeably affected. The infected monkeys showed a marked increase in the levels of superoxide (O2-), lipid peroxidation (LPO), glutathione (GSH) and xanthine oxidase (XO), and decreased levels of superoxide dismutase (SOD) and catalase. Oral administration of chloroquine (20 mg kg body wt-1 for 3 days) to infected monkeys caused recovery trends in oxidative stress and antioxidant defences to almost normal a week after cessation of drug treatment.
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Affiliation(s)
- P Srivastava
- Division of Biochemistry, Central Drug Research Institute, Lucknow, India
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