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Adams Y, Jensen AR. Cerebral malaria - modelling interactions at the blood-brain barrier in vitro. Dis Model Mech 2022; 15:275963. [PMID: 35815443 PMCID: PMC9302004 DOI: 10.1242/dmm.049410] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The blood–brain barrier (BBB) is a continuous endothelial barrier that is supported by pericytes and astrocytes and regulates the passage of solutes between the bloodstream and the brain. This structure is called the neurovascular unit and serves to protect the brain from blood-borne disease-causing agents and other risk factors. In the past decade, great strides have been made to investigate the neurovascular unit for delivery of chemotherapeutics and for understanding how pathogens can circumvent the barrier, leading to severe and, at times, fatal complications. One such complication is cerebral malaria, in which Plasmodium falciparum-infected red blood cells disrupt the barrier function of the BBB, causing severe brain swelling. Multiple in vitro models of the BBB are available to investigate the mechanisms underlying the pathogenesis of cerebral malaria and other diseases. These range from single-cell monolayer cultures to multicellular BBB organoids and highly complex cerebral organoids. Here, we review the technologies available in malaria research to investigate the interaction between P. falciparum-infected red blood cells and the BBB, and discuss the advantages and disadvantages of each model. Summary: This Review discusses the available in vitro models to investigate the impact of adhesion of Plasmodium falciparum-infected red blood cells on the blood–brain barrier, a process associated with cerebral malaria.
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Affiliation(s)
- Yvonne Adams
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Anja Ramstedt Jensen
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
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2
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Oleinikov AV. Malaria Parasite Plasmodium falciparum Proteins on the Surface of Infected Erythrocytes as Targets for Novel Drug Discovery. BIOCHEMISTRY (MOSCOW) 2022; 87:S192-S177. [PMID: 35501996 PMCID: PMC8802247 DOI: 10.1134/s0006297922140152] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Specific adhesion (sequestration) of Plasmodium falciparum parasite-infected erythrocytes (IEs) in deep vascular beds can cause severe complications resulting in death. This review describes our work on the discovery, characterization, and optimization of novel inhibitors that specifically prevent adhesion of IEs to the host vasculature during severe malaria, especially its placental and cerebral forms. The main idea of using anti-adhesion drugs in severe malaria is to release sequestered parasites (or prevent additional sequestration) as quickly as possible. This may significantly improve the outcomes for patients with severe malaria by decreasing local and systemic inflammation associated with the disease and reestablishing the microvascular blood flow. To identify anti-malarial adhesion-inhibiting molecules, we have developed a high-throughput (HT) screening approach and found a number of promising leads that can be further developed into anti-adhesion drugs providing an efficient adjunct therapy against severe forms of malaria.
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Affiliation(s)
- Andrew V Oleinikov
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33428, USA.
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3
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Dos Santos AN, de L Nascimento TR, Gondim BLC, Velo MMAC, de A Rêgo RI, do C Neto JR, Machado JR, da Silva MV, de Araújo HWC, Fonseca MG, Castellano LRC. Catechins as Model Bioactive Compounds for Biomedical Applications. Curr Pharm Des 2021; 26:4032-4047. [PMID: 32493187 DOI: 10.2174/1381612826666200603124418] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/12/2020] [Indexed: 12/28/2022]
Abstract
Research regarding polyphenols has gained prominence over the years because of their potential as pharmacological nutrients. Most polyphenols are flavanols, commonly known as catechins, which are present in high amounts in green tea. Catechins are promising candidates in the field of biomedicine. The health benefits of catechins, notably their antioxidant effects, are related to their chemical structure and the total number of hydroxyl groups. In addition, catechins possess strong activities against several pathogens, including bacteria, viruses, parasites, and fungi. One major limitation of these compounds is low bioavailability. Catechins are poorly absorbed by intestinal barriers. Some protective mechanisms may be required to maintain or even increase the stability and bioavailability of these molecules within living organisms. Moreover, novel delivery systems, such as scaffolds, fibers, sponges, and capsules, have been proposed. This review focuses on the unique structures and bioactive properties of catechins and their role in inflammatory responses as well as provides a perspective on their use in future human health applications.
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Affiliation(s)
- Adriana N Dos Santos
- Human Immunology Research and Education Group (GEPIH), Technical School of Health, Federal University of Paraiba, Joao Pessoa, PB, Brazil
| | - Tatiana R de L Nascimento
- Human Immunology Research and Education Group (GEPIH), Technical School of Health, Federal University of Paraiba, Joao Pessoa, PB, Brazil
| | - Brenna L C Gondim
- Post-Graduation Program in Dentistry, Department of Dentistry, State University of Paraiba, Campina Grande, PB, Brazil
| | - Marilia M A C Velo
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, SP, Brazil
| | - Renaly I de A Rêgo
- Post-Graduation Program in Pharmaceutical Sciences, Department of Pharmaceutical Sciences, State University of Paraiba, Campina Grande, PB, Brazil
| | - José R do C Neto
- Post-Graduation Program in Tropical Medicine and Public Health, Institute of Tropical Pathology and Public Health, Federal University of Goias, Goiania, GO, Brazil
| | - Juliana R Machado
- Post-Graduation Program in Tropical Medicine and Public Health, Institute of Tropical Pathology and Public Health, Federal University of Goias, Goiania, GO, Brazil
| | - Marcos V da Silva
- Department of Microbiology, Immunology and Parasitology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Helvia W C de Araújo
- Department of Chemistry, State University of Paraíba, Campina Grande, PB, Brazil
| | - Maria G Fonseca
- Research Center for Fuels and Materials (NPE - LACOM), Department of Chemistry, Federal University of Paraiba, Joao Pessoa, PB, Brazil
| | - Lúcio R C Castellano
- Human Immunology Research and Education Group (GEPIH), Technical School of Health, Federal University of Paraiba, Joao Pessoa, PB, Brazil
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4
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Recent developments of gallic acid derivatives and their hybrids in medicinal chemistry: A review. Eur J Med Chem 2020; 204:112609. [DOI: 10.1016/j.ejmech.2020.112609] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 02/07/2023]
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5
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Thillainayagam M, Malathi K, Ramaiah S. In-Silico molecular docking and simulation studies on novel chalcone and flavone hybrid derivatives with 1, 2, 3-triazole linkage as vital inhibitors of Plasmodium falciparum dihydroorotate dehydrogenase. J Biomol Struct Dyn 2017; 36:3993-4009. [DOI: 10.1080/07391102.2017.1404935] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Mahalakshmi Thillainayagam
- Medical & Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore 632 014, TamilNadu, India
| | - Kullappan Malathi
- Medical & Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore 632 014, TamilNadu, India
| | - Sudha Ramaiah
- Medical & Biological Computing Laboratory, School of Biosciences and Technology, Vellore Institute of Technology (VIT), Vellore 632 014, TamilNadu, India
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6
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Langhorne J, Duffy PE. Expanding the antimalarial toolkit: Targeting host-parasite interactions. J Exp Med 2016; 213:143-53. [PMID: 26834158 PMCID: PMC4749928 DOI: 10.1084/jem.20151677] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 12/21/2015] [Indexed: 12/27/2022] Open
Abstract
Recent successes in malaria control are threatened by drug-resistant Plasmodium parasites and insecticide-resistant Anopheles mosquitoes, and first generation vaccines offer only partial protection. New research approaches have highlighted host as well as parasite molecules or pathways that could be targeted for interventions. In this study, we discuss host–parasite interactions at the different stages of the Plasmodium life cycle within the mammalian host and the potential for therapeutics that prevent parasite migration, invasion, intracellular growth, or egress from host cells, as well as parasite-induced pathology.
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Affiliation(s)
- Jean Langhorne
- Mill Hill Laboratory, The Francis Crick Institute, London NW7 1AA, England, UK
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
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7
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Helgren TR, Sciotti RJ, Lee P, Duffy S, Avery VM, Igbinoba O, Akoto M, Hagen TJ. The synthesis, antimalarial activity and CoMFA analysis of novel aminoalkylated quercetin analogs. Bioorg Med Chem Lett 2014; 25:327-32. [PMID: 25488841 DOI: 10.1016/j.bmcl.2014.11.039] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 11/25/2022]
Abstract
A series of novel aminoalkylated quercetin analogs, prepared via the Mannich reaction of various primary and secondary amines with formaldehyde, were tested for antimalarial activity. The compounds were screened against three drug resistant malarial strains (D6, C235 and W2) and were found to exhibit sub-micromolar activity across all three strains (0.065-13.0μM). The structure-activity relationship determined from the antimalarial activity data suggests the inclusion of phenethyl amine sidechains on the quercetin scaffolding is necessary for potent activity. Additionally, the most active compounds ((5) and (6)) were tested for both early and late stage anti-gametocytocidal activity. Finally, the antimalarial activity data were utilized to construct comparative molecular field analysis (CoMFA) models to be used for further compound refinement.
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Affiliation(s)
- Travis R Helgren
- Department of Chemistry and Biochemistry, Northern Illinois University, 300 Normal Road, Dekalb, IL 60115, USA
| | - Richard J Sciotti
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, 2460 Linden Lane, Silver Spring, MD 20910, USA
| | - Patricia Lee
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, 2460 Linden Lane, Silver Spring, MD 20910, USA
| | - Sandra Duffy
- Discovery Biology, Eskitis Institute for Drug Discovery, Griffith University, 170 Kessels Road, Nathan, Queensland 4111, Australia
| | - Vicky M Avery
- Discovery Biology, Eskitis Institute for Drug Discovery, Griffith University, 170 Kessels Road, Nathan, Queensland 4111, Australia
| | - Osayawemwen Igbinoba
- Department of Chemistry and Biochemistry, Northern Illinois University, 300 Normal Road, Dekalb, IL 60115, USA
| | - Matthew Akoto
- Department of Chemistry and Biochemistry, Northern Illinois University, 300 Normal Road, Dekalb, IL 60115, USA
| | - Timothy J Hagen
- Department of Chemistry and Biochemistry, Northern Illinois University, 300 Normal Road, Dekalb, IL 60115, USA
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Madkhali AM, Alkurbi MO, Szestak T, Bengtsson A, Patil PR, Wu Y, Alharthi S, Jensen ATR, Pleass R, Craig AG. An analysis of the binding characteristics of a panel of recently selected ICAM-1 binding Plasmodium falciparum patient isolates. PLoS One 2014; 9:e111518. [PMID: 25360558 PMCID: PMC4216080 DOI: 10.1371/journal.pone.0111518] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 09/30/2014] [Indexed: 12/21/2022] Open
Abstract
The basis of severe malaria pathogenesis in part includes sequestration of Plasmodium falciparum-infected erythrocytes (IE) from the peripheral circulation. This phenomenon is mediated by the interaction between several endothelial receptors and one of the main parasite-derived variant antigens (PfEMP1) expressed on the surface of the infected erythrocyte membrane. One of the commonly used host receptors is ICAM-1, and it has been suggested that ICAM-1 has a role in cerebral malaria pathology, although the evidence to support this is not conclusive. The current study examined the cytoadherence patterns of lab-adapted patient isolates after selecting on ICAM-1. We investigated the binding phenotypes using variant ICAM-1 proteins including ICAM-1Ref, ICAM-1Kilifi, ICAM-1S22/A, ICAM-1L42/A and ICAM-1L44/A using static assays. The study also examined ICAM-1 blocking by four anti-ICAM-1 monoclonal antibodies (mAb) under static conditions. We also characterised the binding phenotypes using Human Dermal Microvascular Endothelial Cells (HDMEC) under flow conditions. The results show that different isolates have variant-specific binding phenotypes under both static and flow conditions, extending our previous observations that this variation might be due to variable contact residues on ICAM-1 being used by different parasite PfEMP1 variants.
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Affiliation(s)
- Aymen M. Madkhali
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Medical Laboratories Technology, College of Applied Medical Sciences, Jazan University, Jazan, Kingdom of Saudi Arabia
| | - Mohammed O. Alkurbi
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Laboratory Medicine, College of Applied Medical Sciences, Umm Al-Qura University, Makkah Al-Mukarramah, Kingdom of Saudi Arabia
| | - Tadge Szestak
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Anja Bengtsson
- Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pradeep R. Patil
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Yang Wu
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Saeed Alharthi
- Department of Laboratory Medicine, College of Applied Medical Sciences, Umm Al-Qura University, Makkah Al-Mukarramah, Kingdom of Saudi Arabia
| | - Anja T. R. Jensen
- Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Richard Pleass
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Alister G. Craig
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
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9
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Gullingsrud J, Milman N, Saveria T, Chesnokov O, Williamson K, Srivastava A, Gamain B, Duffy PE, Oleinikov AV. High-throughput screening platform identifies small molecules that prevent sequestration of Plasmodium falciparum-infected erythrocytes. J Infect Dis 2014; 211:1134-43. [PMID: 25355939 DOI: 10.1093/infdis/jiu589] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND We developed a 2-step approach to screen molecules that prevent and/or reverse Plasmodium falciparum-infected erythrocyte (IE) binding to host receptors. IE adhesion and sequestration in vasculature causes severe malaria, and therefore antiadhesion therapy might be useful as adjunctive treatment. IE adhesion is mediated by the polymorphic family (approximately 60 members) of P. falciparum EMP1 (PfEMP1) multidomain proteins. METHODS We constructed sets of PfEMP1 domains that bind ICAM-1, CSA, or CD36, receptors that commonly support IE binding. Combinations of domain-coated beads were assayed by Bio-Plex technology as a high-throughput molecular platform to screen antiadhesion molecules (antibodies and small molecules). Molecules identified as so-called hits in the screen (first step) then could be assayed individually for inhibition of binding of live IE to receptors (second step). RESULTS In proof-of-principle studies, the antiadhesion activity of several antibodies was concordant in Bio-Plex and live IE assays. Using this 2-step approach, we identified several molecules in a small molecule library of 10 000 compounds that could inhibit and reverse binding of IEs to ICAM-1 and CSA receptors. CONCLUSION This 2-step screening approach should be efficient for identification of antiadhesion drug candidates for falciparum malaria.
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Affiliation(s)
| | - Neta Milman
- Seattle Biomedical Research Institute, Seattle, Washington
| | - Tracy Saveria
- Seattle Biomedical Research Institute, Seattle, Washington
| | - Olga Chesnokov
- Charles E. Schmidt College of Medicine, Department of Biomedical Science, Florida Atlantic University, Boca Raton
| | | | - Anand Srivastava
- Inserm UMR 1134 Université Paris Diderot, Sorbonne Paris Cité, UMR S1134 Institut National de la Transfusion Sanguine, Paris, France
| | - Benoit Gamain
- Inserm UMR 1134 Université Paris Diderot, Sorbonne Paris Cité, UMR S1134 Institut National de la Transfusion Sanguine, Paris, France
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institutes of Health, Bethesda, Maryland
| | - Andrew V Oleinikov
- Seattle Biomedical Research Institute, Seattle, Washington Charles E. Schmidt College of Medicine, Department of Biomedical Science, Florida Atlantic University, Boca Raton
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10
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Singh M, Kaur M, Silakari O. Flavones: an important scaffold for medicinal chemistry. Eur J Med Chem 2014; 84:206-39. [PMID: 25019478 DOI: 10.1016/j.ejmech.2014.07.013] [Citation(s) in RCA: 332] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/03/2014] [Accepted: 07/05/2014] [Indexed: 01/31/2023]
Abstract
Flavones have antioxidant, anti-proliferative, anti-tumor, anti-microbial, estrogenic, acetyl cholinesterase, anti-inflammatory activities and are also used in cancer, cardiovascular disease, neurodegenerative disorders, etc. Also, flavonoids are found to have an effect on several mammalian enzymes like protein kinases that regulate multiple cell signaling pathways and alterations in multiple cellular signaling pathways are frequently found in many diseases. Flavones have been an indispensable anchor for the development of new therapeutic agents. The majority of metabolic diseases are speculated to originate from oxidative stress, and it is therefore significant that recent studies have shown the positive effect of flavones on diseases related to oxidative stress. Due to the wide range of biological activities of flavones, their structure-activity relationships have generated interest among medicinal chemists. The outstanding development of flavones derivatives in diverse diseases in very short span of time proves its magnitude for medicinal chemistry research. The present review gives detail about the structural requirement of flavone derivatives for various pharmacological activities. This information may provide an opportunity to scientists of medicinal chemistry discipline to design selective, optimize as well as poly-functional flavone derivatives for the treatment of multi-factorial diseases.
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Affiliation(s)
- Manjinder Singh
- Molecular Modeling Lab, Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab 147002, India
| | - Maninder Kaur
- Molecular Modeling Lab, Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab 147002, India
| | - Om Silakari
- Molecular Modeling Lab, Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab 147002, India.
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Gemma S, Brogi S, Patil PR, Giovani S, Lamponi S, Cappelli A, Novellino E, Brown A, Higgins MK, Mustafa K, Szestak T, Craig AG, Campiani G, Butini S, Brindisi M. From (+)-epigallocatechin gallate to a simplified synthetic analogue as a cytoadherence inhibitor for P. falciparum. RSC Adv 2014. [DOI: 10.1039/c3ra45933k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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12
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Maranz S. An alternative paradigm for the role of antimalarial plants in Africa. ScientificWorldJournal 2012; 2012:978913. [PMID: 22593717 PMCID: PMC3346345 DOI: 10.1100/2012/978913] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 12/15/2011] [Indexed: 11/17/2022] Open
Abstract
Most investigations into the antimalarial activity of African plants are centered on finding an indigenous equivalent to artemisinin, the compound from which current frontline antimalarial drugs are synthesized. As a consequence, the standard practice in ethnopharmacological research is to use in vitro assays to identify compounds that inhibit parasites at nanomolar concentrations. This approach fails to take into consideration the high probability of acquisition of resistance to parasiticidal compounds since parasite populations are placed under direct selection for genetic that confers a survival advantage. Bearing in mind Africa's long exposure to malaria and extensive ethnobotanical experimentation with both therapies and diet, it is more likely that compounds not readily overcome by Plasmodium parasites would have been retained in the pharmacopeia and cuisine. Such compounds are characterized by acting primarily on the host rather than directly targeting the parasite and thus cannot be adequately explored in vitro. If Africa's long history with malaria has in fact produced effective plant therapies, their scientific elucidation will require a major emphasis on in vivo investigation.
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Affiliation(s)
- Steven Maranz
- David H. Murdock Research Institute, Kannapolis, NC 28081, USA.
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13
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Alister GC, Mohd Fadzli Mustaffa K. Cytoadherence and severe malaria. Malays J Med Sci 2012; 19:5-18. [PMID: 22973133 PMCID: PMC3431742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 11/15/2011] [Indexed: 06/01/2023] Open
Abstract
Malaria is a disease that causes enormous human morbidity and mortality. One feature of mature Plasmodium falciparum-infected erythrocytes leading to the development of severe malaria is thought to be cytoadherence and blockage of the microvasculature. Therefore, an understanding of mechanisms that mediate parasite adhesion leading to malaria pathology is needed to yield new treatments for malaria. However, to date, cytoadherence-associated pathology is still under debate. Is cytoadherence needed to develop severe malaria? This review will discuss the available information on associations of cytoadherence with the development of severe malaria.
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Affiliation(s)
- G Craig Alister
- Department of Molecular and Biochemical
Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA
Liverpool, United Kingdom
| | - Khairul Mohd Fadzli Mustaffa
- Department of Molecular and Biochemical
Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA
Liverpool, United Kingdom
- Institute for Research in Molecular
Medicine, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan,
Malaysia
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14
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Patil PR, Gemma S, Campiani G, Craig AG. Broad inhibition of plasmodium falciparum cytoadherence by (+)-epigallocatechin gallate. Malar J 2011; 10:348. [PMID: 22132804 PMCID: PMC3260111 DOI: 10.1186/1475-2875-10-348] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 12/01/2011] [Indexed: 11/15/2022] Open
Abstract
Background The surface antigen PfEMP-1 is a key virulence factor of the human malaria parasite implicated in the cytoadherence of Plasmodium falciparum infected erythrocytes to a range of receptors on host endothelium. Among these host receptors, binding to ICAM-1 is related to cerebral malaria. The majority of the mortality in children with cerebral malaria is seen within 24 h of hospital admission despite the use of effective anti-parasite drugs, therefore, the development of adjunctive therapies is urgently needed. The polyphenolic compound (+)-epigallocatechin gallate ((+)-EGCG) has been previously evaluated for anti-adhesive properties using a small number of laboratory parasite isolates. Here, this property is further explored using a new panel of ICAM-1-binding patient isolates of P. falciparum to ascertain if (+)-EGCG might be effective as a broad spectrum inhibitor of ICAM-1-based cytoadherence. Methods Plasmodium falciparum lines, including A4 and ItG as positive controls and nine new ICAM-1 binding patient isolates, were allowed to bind with ICAM-1-Fc protein under static assay conditions in the presence and absence of 50 μM (+)-EGCG. Adhesion levels of all the parasite strains were quantified by microscopy as the mean number of infected erythrocyte (IE) bound per mm2 of surface area and statistical comparisons were made to demonstrate the effect of (+)-EGCG on the binding of various parasite variants to human ICAM-1. Results This study revealed that binding of patient isolates to ICAM-1 was reduced significantly with inhibition levels of 37% in patient isolate BC-12 up to a maximum of 80% in patient isolate 8146 at 50 μM (+)-EGCG. Conclusion Evaluation of the anti-adhesive property of (+)-EGCG against a new panel of ICAM-1-binding patient isolates of P. falciparum showed that this inhibitor, identified as potential mimic of the L43 loop of human ICAM-1, was effective at blocking cytoadherence.
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Affiliation(s)
- Pradeep R Patil
- European Research Centre for Drug Discovery and Development, Department of Pharmaceutical and Applied Chemistry, University of Siena, Italy
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15
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Grimberg BT, Mehlotra RK. Expanding the Antimalarial Drug Arsenal-Now, But How? Pharmaceuticals (Basel) 2011; 4:681-712. [PMID: 21625331 PMCID: PMC3102560 DOI: 10.3390/ph4050681] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Revised: 04/09/2011] [Accepted: 04/19/2011] [Indexed: 01/24/2023] Open
Abstract
The number of available and effective antimalarial drugs is quickly dwindling. This is mainly because a number of drug resistance-associated mutations in malaria parasite genes, such as crt, mdr1, dhfr/dhps, and others, have led to widespread resistance to all known classes of antimalarial compounds. Unfortunately, malaria parasites have started to exhibit some level of resistance in Southeast Asia even to the most recently introduced class of drugs, artemisinins. While there is much need, the antimalarial drug development pipeline remains woefully thin, with little chemical diversity, and there is currently no alternative to the precious artemisinins. It is difficult to predict where the next generation of antimalarial drugs will come from; however, there are six major approaches: (i) re-optimizing the use of existing antimalarials by either replacement/rotation or combination approach; (ii) repurposing drugs that are currently used to treat other infections or diseases; (iii) chemically modifying existing antimalarial compounds; (iv) exploring natural sources; (v) large-scale screening of diverse chemical libraries; and (vi) through parasite genome-based ("targeted") discoveries. When any newly discovered effective antimalarial treatment is used by the populus, we must maintain constant vigilance for both parasite-specific and human-related factors that are likely to hamper its success. This article is neither comprehensive nor conclusive. Our purpose is to provide an overview of antimalarial drug resistance, associated parasite genetic factors (1. Introduction; 2. Emergence of artemisinin resistance in P. falciparum), and the antimalarial drug development pipeline (3. Overview of the global pipeline of antimalarial drugs), and highlight some examples of the aforementioned approaches to future antimalarial treatment. These approaches can be categorized into "short term" (4. Feasible options for now) and "long term" (5. Next generation of antimalarial treatment-Approaches and candidates). However, these two categories are interrelated, and the approaches in both should be implemented in parallel with focus on developing a successful, long-lasting antimalarial chemotherapy.
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Affiliation(s)
- Brian T. Grimberg
- Center for Global Health and Diseases, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; E-Mails: (B.T.G.); (R.K.M.); Tel.: +1-216-368-6328 or +1-216-368-6172, Fax: +1-216-368-4825
| | - Rajeev K. Mehlotra
- Center for Global Health and Diseases, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; E-Mails: (B.T.G.); (R.K.M.); Tel.: +1-216-368-6328 or +1-216-368-6172, Fax: +1-216-368-4825
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Casano G, Dumètre A, Pannecouque C, Hutter S, Azas N, Robin M. Anti-HIV and antiplasmodial activity of original flavonoid derivatives. Bioorg Med Chem 2010; 18:6012-23. [PMID: 20638854 DOI: 10.1016/j.bmc.2010.06.067] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 06/10/2010] [Accepted: 06/21/2010] [Indexed: 10/19/2022]
Abstract
In our search for potent anti-HIV and antiplasmodial agents, novel series of flavonoid derivatives and their chalcone intermediates were synthesized and evaluated for inhibition of HIV multiplication and antiproliferative activity on Plasmodium falciparum parasites. Chalcones exhibited a more selective antiplasmodial activity than flavonoids. Methoxyflavone 7e was the only one compound active in both P. falciparum and HIV-1 whereas aminomethoxyflavones showed activity against HIV-2. Para substitution on the B ring seemed to increase HIV-2 potency.
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Affiliation(s)
- Gilles Casano
- Aix-Marseille Université, Institut des Sciences Moléculaires de Marseille, iSm2-UMR CNRS, Centre Saint Jérôme, Marseille Cedex 20, France
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17
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Hellmann JK, Münter S, Wink M, Frischknecht F. Synergistic and additive effects of epigallocatechin gallate and digitonin on Plasmodium sporozoite survival and motility. PLoS One 2010; 5:e8682. [PMID: 20072627 PMCID: PMC2800191 DOI: 10.1371/journal.pone.0008682] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 12/15/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Most medicinal plants contain a mixture of bioactive compounds, including chemicals that interact with intracellular targets and others that can act as adjuvants to facilitate absorption of polar agents across cellular membranes. However, little is known about synergistic effects between such potential drug candidates and adjuvants. To probe for such effects, we tested the green tea compound epigallocatechin gallate (EGCG) and the membrane permeabilising digitonin on Plasmodium sporozoite motility and viability. METHODOLOGY/PRINCIPAL FINDINGS Green fluorescent P. berghei sporozoites were imaged using a recently developed visual screening methodology. Motility and viability parameters were automatically analyzed and IC50 values were calculated, and the synergism of drug and adjuvant was assessed by the fractional inhibitory concentration index. Validating our visual screening procedure, we showed that sporozoite motility and liver cell infection is inhibited by EGCG at nontoxic concentrations. Digitonin synergistically increases the cytotoxicity of EGCG on sporozoite survival, but shows an additive effect on sporozoite motility. CONCLUSIONS/SIGNIFICANCE We proved the feasibility of performing highly reliable visual screens for compounds against Plasmodium sporozoites. We thereby could show an advantage of administering mixtures of plant metabolites on inhibition of cell motility and survival. Although the effective concentration of both drugs is too high for use in malaria prophylaxis, the demonstration of a synergistic effect between two plant compounds could lead to new avenues in drug discovery.
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Affiliation(s)
- Janina K. Hellmann
- Department of Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
| | - Sylvia Münter
- Department of Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
| | - Michael Wink
- Department of Biology, University of Heidelberg, Heidelberg, Germany
- * E-mail: (MW); (FF)
| | - Friedrich Frischknecht
- Department of Biology, University of Heidelberg, Heidelberg, Germany
- * E-mail: (MW); (FF)
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Adhesion of Plasmodium falciparum-infected erythrocytes to human cells: molecular mechanisms and therapeutic implications. Expert Rev Mol Med 2009; 11:e16. [PMID: 19467172 PMCID: PMC2878476 DOI: 10.1017/s1462399409001082] [Citation(s) in RCA: 249] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Severe malaria has a high mortality rate (15–20%) despite treatment with
effective antimalarial drugs. Adjunctive therapies for severe malaria that target the
underlying disease process are therefore urgently required. Adhesion of erythrocytes
infected with Plasmodium falciparum to human cells has a key role in the
pathogenesis of life-threatening malaria and could be targeted with antiadhesion therapy.
Parasite adhesion interactions include binding to endothelial cells (cytoadherence),
rosetting with uninfected erythrocytes and platelet-mediated clumping of infected
erythrocytes. Recent research has started to define the molecular mechanisms of parasite
adhesion, and antiadhesion therapies are being explored. However, many fundamental
questions regarding the role of parasite adhesion in severe malaria remain unanswered.
There is strong evidence that rosetting contributes to severe malaria in sub-Saharan
Africa; however, the identity of other parasite adhesion phenotypes that are implicated in
disease pathogenesis remains unclear. In addition, the possibility of geographic variation
in adhesion phenotypes causing severe malaria, linked to differences in malaria
transmission levels and host immunity, has been neglected. Further research is needed to
realise the untapped potential of antiadhesion adjunctive therapies, which could
revolutionise the treatment of severe malaria and reduce the high mortality rate of the
disease.
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19
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Sherman IW. References. ADVANCES IN PARASITOLOGY 2008. [DOI: 10.1016/s0065-308x(08)00430-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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