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García-Estrada C, Pérez-Pertejo Y, Domínguez-Asenjo B, Holanda VN, Murugesan S, Martínez-Valladares M, Balaña-Fouce R, Reguera RM. Further Investigations of Nitroheterocyclic Compounds as Potential Antikinetoplastid Drug Candidates. Biomolecules 2023; 13:biom13040637. [PMID: 37189384 DOI: 10.3390/biom13040637] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
Due to the lack of specific vaccines, management of the trypanosomatid-caused neglected tropical diseases (sleeping sickness, Chagas disease and leishmaniasis) relies exclusively on pharmacological treatments. Current drugs against them are scarce, old and exhibit disadvantages, such as adverse effects, parenteral administration, chemical instability and high costs which are often unaffordable for endemic low-income countries. Discoveries of new pharmacological entities for the treatment of these diseases are scarce, since most of the big pharmaceutical companies find this market unattractive. In order to fill the pipeline of compounds and replace existing ones, highly translatable drug screening platforms have been developed in the last two decades. Thousands of molecules have been tested, including nitroheterocyclic compounds, such as benznidazole and nifurtimox, which had already provided potent and effective effects against Chagas disease. More recently, fexinidazole has been added as a new drug against African trypanosomiasis. Despite the success of nitroheterocycles, they had been discarded from drug discovery campaigns due to their mutagenic potential, but now they represent a promising source of inspiration for oral drugs that can replace those currently on the market. The examples provided by the trypanocidal activity of fexinidazole and the promising efficacy of the derivative DNDi-0690 against leishmaniasis seem to open a new window of opportunity for these compounds that were discovered in the 1960s. In this review, we show the current uses of nitroheterocycles and the novel derived molecules that are being synthesized against these neglected diseases.
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Affiliation(s)
- Carlos García-Estrada
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Yolanda Pérez-Pertejo
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Bárbara Domínguez-Asenjo
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Vanderlan Nogueira Holanda
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Sankaranarayanan Murugesan
- Medicinal Chemistry Research Laboratory, Department of Pharmacy, Birla Institute of Technology and Science Pilani, Pilani Campus, Pilani 333031, India
| | - María Martínez-Valladares
- Instituto de Ganadería de Montaña (IGM), Consejo Superior de Investigaciones Científicas-Universidad de León, Carretera León-Vega de Infanzones, Vega de Infanzones, 24346 León, Spain
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Rafael Balaña-Fouce
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Rosa M. Reguera
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
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Qureshi IA, Saini M, Are S. Pyridoxal Kinase of Disease-causing Human Parasites: Structural and
Functional Insights to Understand its Role in Drug Discovery. Curr Protein Pept Sci 2022; 23:271-289. [DOI: 10.2174/1389203723666220519155025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/14/2022] [Accepted: 04/06/2022] [Indexed: 11/22/2022]
Abstract
Abstract:
Human parasites cause several diseased conditions with high morbidity and mortality in a
large section of the population residing in various geographical areas. Nearly three billion people suffer
from either one or many parasitic infections globally, with almost one million deaths annually. In spite
of extensive research and advancement in the medical field, no effective vaccine is available against
prominent human parasitic diseases that necessitate identification of novel targets for designing specific
inhibitors. Vitamin B6 is an important ubiquitous co-enzyme that participates in several biological processes
and plays an important role in scavenging ROS (reactive oxygen species) along with providing
resistance to oxidative stress. Moreover, the absence of the de novo vitamin B6 biosynthetic pathway in
human parasites makes this pathway indispensable for the survival of these pathogens. Pyridoxal kinase
(PdxK) is a crucial enzyme for vitamin B6 salvage pathway and participates in the process of vitamers
B6 phosphorylation. Since the parasites are dependent on pyridoxal kinase for their survival and infectivity
to the respective hosts, it is considered a promising candidate for drug discovery. The detailed
structural analysis of PdxK from disease-causing parasites has provided insights into the catalytic
mechanism of this enzyme as well as significant differences from their human counterpart. Simultaneously,
structure-based studies have identified small lead molecules that can be exploited for drug discovery
against protozoan parasites. The present review provides structural and functional highlights of
pyridoxal kinase for its implication in developing novel and potent therapeutics to combat fatal parasitic
diseases.
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Affiliation(s)
- Insaf Ahmed Qureshi
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao
Road, Hyderabad 500046, India
| | - Mayank Saini
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao
Road, Hyderabad 500046, India
| | - Sayanna Are
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao
Road, Hyderabad 500046, India
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Abstract
Pentamidine (PTM), which is a diamine that is widely known for its antimicrobial activity, is a very interesting drug whose mechanism of action is not fully understood. In recent years, PTM has been proposed as a novel potential drug candidate for the treatment of mental illnesses, myotonic dystrophy, diabetes, and tumors. Nevertheless, the systemic administration of PTM causes severe side effects, especially nephrotoxicity. In order to efficiently deliver PTM and reduce its side effects, several nanosystems that take advantage of the chemical characteristics of PTM, such as the presence of two positively charged amidine groups at physiological pH, have been proposed as useful delivery tools. Polymeric, lipidic, inorganic, and other types of nanocarriers have been reported in the literature for PTM delivery, and they are all in different development phases. The available approaches for the design of PTM nanoparticulate delivery systems are reported in this review, with a particular emphasis on formulation strategies and in vitro/in vivo applications. Furthermore, a critical view of the future developments of nanomedicine for PTM applications, based on recent repurposing studies, is provided. Created with BioRender.com.
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Sanderson L, da Silva M, Sekhar GN, Brown RC, Burrell-Saward H, Fidanboylu M, Liu B, Dailey LA, Dreiss CA, Lorenz C, Christie M, Persaud SJ, Yardley V, Croft SL, Valero M, Thomas SA. Drug reformulation for a neglected disease. The NANOHAT project to develop a safer more effective sleeping sickness drug. PLoS Negl Trop Dis 2021; 15:e0009276. [PMID: 33857146 PMCID: PMC8078842 DOI: 10.1371/journal.pntd.0009276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/27/2021] [Accepted: 02/26/2021] [Indexed: 01/16/2023] Open
Abstract
Background Human African trypanosomiasis (HAT or sleeping sickness) is caused by the
parasite Trypanosoma brucei sspp. The disease has two
stages, a haemolymphatic stage after the bite of an infected tsetse fly,
followed by a central nervous system stage where the parasite penetrates the
brain, causing death if untreated. Treatment is stage-specific, due to the
blood-brain barrier, with less toxic drugs such as pentamidine used to treat
stage 1. The objective of our research programme was to develop an
intravenous formulation of pentamidine which increases CNS exposure by some
10–100 fold, leading to efficacy against a model of stage 2 HAT. This target
candidate profile is in line with drugs for neglected diseases inititative
recommendations. Methodology To do this, we evaluated the physicochemical and structural characteristics
of formulations of pentamidine with Pluronic micelles (triblock-copolymers
of polyethylene-oxide and polypropylene oxide), selected candidates for
efficacy and toxicity evaluation in vitro, quantified
pentamidine CNS delivery of a sub-set of formulations in vitro and
in vivo, and progressed one pentamidine-Pluronic formulation
for further evaluation using an in vivo single dose brain
penetration study. Principal Findings Screening pentamidine against 40 CNS targets did not reveal any major
neurotoxicity concerns, however, pentamidine had a high affinity for the
imidazoline2 receptor. The reduction in insulin secretion in
MIN6 β-cells by pentamidine may be secondary to pentamidine-mediated
activation of β-cell imidazoline receptors and impairment of cell viability.
Pluronic F68 (0.01%w/v)-pentamidine formulation had a similar inhibitory
effect on insulin secretion as pentamidine alone and an additive
trypanocidal effect in vitro. However, all Pluronics tested
(P85, P105 and F68) did not significantly enhance brain exposure of
pentamidine. Significance These results are relevant to further developing block-copolymers as
nanocarriers, improving BBB drug penetration and understanding the side
effects of pentamidine. Sleeping sickness or human African Trypanosomiasis (HAT) is a disease caused by a
parasite, which is transferred to humans by the bite of an infected tsetse fly.
There are two disease stages: the first stage is the blood-based stage of the
disease and the second stage affects the brain. It is fatal if left untreated.
The blood-brain barrier (BBB) makes the brain stage difficult to treat because
it prevents 99% of all drugs from entering the brain from the blood. Those
anti-HAT drugs that do enter the brain are toxic and have serious side effects.
Pentamidine is a less toxic blood stage drug, which our research has shown has a
limited ability to cross the BBB due to its removal by proteins called
transporters. The objective of this study was to use Pluronic to improve
pentamidine delivery to target sites, whilst reducing its side effects. Pluronic
is a polymer, which can assemble into micelles and encapsulate the drug. Thus,
prolonging its circulation time and protecting it. Our study indicated that the
selected Pluronics did not increase the brain delivery of pentamidine. However.
Pluronic-pentamidine formulations were identified that harboured trypanocidal
activity and did not increase safety concerns compared to unformulated
pentamidine.
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Affiliation(s)
- Lisa Sanderson
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Marcelo da Silva
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Gayathri N. Sekhar
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Rachel C. Brown
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Hollie Burrell-Saward
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and
Tropical Medicine, London, United Kingdom
| | - Mehmet Fidanboylu
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Bo Liu
- King’s College London, Department of Diabetes, School of Life Course
Sciences, Faculty of Life Sciences & Medicine, London, United
Kingdom
| | - Lea Ann Dailey
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Cécile A. Dreiss
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Chris Lorenz
- King’s College London, Theory & Simulation of Condensed Matter Group,
Department of Physics, Strand, London, United Kingdom
| | - Mark Christie
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Shanta J. Persaud
- King’s College London, Department of Diabetes, School of Life Course
Sciences, Faculty of Life Sciences & Medicine, London, United
Kingdom
| | - Vanessa Yardley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and
Tropical Medicine, London, United Kingdom
| | - Simon L. Croft
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and
Tropical Medicine, London, United Kingdom
| | - Margarita Valero
- Physical Chemistry Department, Faculty of Pharmacy, University of
Salamanca, Salamanca, Spain
| | - Sarah A. Thomas
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
- * E-mail:
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Beteck RM, Jordaan A, Seldon R, Laming D, Hoppe HC, Warner DF, Khanye SD. Easy-To-Access Quinolone Derivatives Exhibiting Antibacterial and Anti-Parasitic Activities. Molecules 2021; 26:molecules26041141. [PMID: 33672753 PMCID: PMC7931078 DOI: 10.3390/molecules26041141] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/11/2021] [Accepted: 02/13/2021] [Indexed: 11/16/2022] Open
Abstract
The cell wall of Mycobacterium tuberculosis (Mtb) has a unique structural organisation, comprising a high lipid content mixed with polysaccharides. This makes cell wall a formidable barrier impermeable to hydrophilic agents. In addition, during host infection, Mtb resides in macrophages within avascular necrotic granulomas and cavities, which shield the bacterium from the action of most antibiotics. To overcome these protective barriers, a new class of anti-TB agents exhibiting lipophilic character have been recommended by various reports in literature. Herein, a series of lipophilic heterocyclic quinolone compounds was synthesised and evaluated in vitro against pMSp12::GFP strain of Mtb, two protozoan parasites (Plasmodium falciparum and Trypanosoma brucei brucei) and against ESKAPE pathogens. The resultant compounds exhibited varied anti-Mtb activity with MIC90 values in the range of 0.24–31 µM. Cross-screening against P. falciparum and T.b. brucei, identified several compounds with antiprotozoal activities in the range of 0.4–20 µM. Compounds were generally inactive against ESKAPE pathogens, with only compounds 8c, 8g and 13 exhibiting moderate to poor activity against S. aureus and A. baumannii.
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Affiliation(s)
- Richard M. Beteck
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom 2520, South Africa
- Correspondence: (R.M.B.); (S.D.K.); Tel.: +27-46-603-8397 (S.D.K.)
| | - Audrey Jordaan
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (A.J.); (D.F.W.)
| | - Ronnett Seldon
- SAMRC Drug Discovery and Development Research Unit, University of Cape Town, Cape Town 7700, South Africa;
| | - Dustin Laming
- Centre for Chemico- and Biomedicinal Research, Rhodes University, Makhanda 6140, South Africa; (D.L.); (H.C.H.)
| | - Heinrich C. Hoppe
- Centre for Chemico- and Biomedicinal Research, Rhodes University, Makhanda 6140, South Africa; (D.L.); (H.C.H.)
- Department of Biochemistry and Microbiology, Faculty of Science, Rhodes University, Makhanda 6140, South Africa
| | - Digby F. Warner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town 7925, South Africa; (A.J.); (D.F.W.)
- Wellcome Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town 7925, South Africa
| | - Setshaba D. Khanye
- Centre for Chemico- and Biomedicinal Research, Rhodes University, Makhanda 6140, South Africa; (D.L.); (H.C.H.)
- Division of Pharmaceutical Chemistry, Faculty of Pharmacy, Rhodes University, Makhanda 6140, South Africa
- Correspondence: (R.M.B.); (S.D.K.); Tel.: +27-46-603-8397 (S.D.K.)
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Jesumoroti OJ, Beteck RM, Legoabe LJ. In-vitro Anti-trypanosomal and Cytotoxicity Evaluation of 3-methyl-3,4-dihydroquinazolin-2(1H)-one Derivatives. Drug Res (Stuttg) 2021; 71:335-340. [PMID: 33535253 DOI: 10.1055/a-1349-1256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Sleeping sickness, caused by trypanosomes, is a debilitating, neglected tropical disease wherein current treatments suffer from several drawbacks such as toxicity, low activity, and poor pharmacokinetic properties, and hence the need for alternative treatment is apparent. To this effect, we screened in vitro a library of 2-quinazolinone derivatives for antitrypanosomal activity against T.b. brucei and cytotoxicity against HeLa cells. Seven compounds having no overt cytotoxicity against HeLa cells exhibited antitrypanosomal activity in the range of 0.093-45 µM were identified. The activity data suggests that the antitrypanosomal activity of this compound class is amenable to substituents at N1 and C6 positions. Compound 14: having a molecular weight of 238Da, ClogP value of 1 and a total polar surface area of 49 was identified as the most active, exhibiting an IC50 value of 0.093 µM Graphical Abstract.
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Affiliation(s)
- Omobolanle J Jesumoroti
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
| | - Richard M Beteck
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
| | - Lesetja J Legoabe
- Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
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7
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Alhafiz ZA, Abdulsalami MS, Ibrahim MA, Bulus T, Suleiman AB. Molecular identification of Trypanosoma brucei brucei and in vitro anti-trypanosomal activity of different parts of methanolic extract of Senna occidentalis. CLINICAL PHYTOSCIENCE 2020. [DOI: 10.1186/s40816-020-00178-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Objective
The present study investigated the anti-Trypanosoma brucei brucei activity of methanolic extract of Senna occidentalis roots, leaves, stem bark, and seed in vitro and bioactive components of the most active plant part.
Materials and methods
Trypanosoma brucei brucei was identified by PCR, cultured in Dulbecco’s Modified Eagle Medium (DMEM) and incubated at 37 °C and 5% CO2. Subsequently, the cultured T. brucei brucei were incubated with 500 μg/ml concentration of different parts of S. occidentalis plant and the most potent fraction was identified and subjected to Gas Chromatography-Mass Spectrometry (GC-MS).
Results
Amplicons of the rRNA gene of T. brucei brucei detected had a size of 1200 bp. The anti-trypanosomal activities indicated that the root extract of the plant was the most active at 500 μg/ml with inhibitory activity of 88.89% and fractions (2 and 5) the most active with IC50 values of 1.49 and 1.16 μg/ml respectively.
Conclusion
Results from this study insinuates that phenolic and simple aliphatic compounds might play key role in the anti-trypanosomal activity of S. occidentalis roots.
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Muraca G, Berti IR, Sbaraglini ML, Fávaro WJ, Durán N, Castro GR, Talevi A. Trypanosomatid-Caused Conditions: State of the Art of Therapeutics and Potential Applications of Lipid-Based Nanocarriers. Front Chem 2020; 8:601151. [PMID: 33324615 PMCID: PMC7726426 DOI: 10.3389/fchem.2020.601151] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/19/2020] [Indexed: 11/13/2022] Open
Abstract
Trypanosomatid-caused conditions (African trypanosomiasis, Chagas disease, and leishmaniasis) are neglected tropical infectious diseases that mainly affect socioeconomically vulnerable populations. The available therapeutics display substantial limitations, among them limited efficacy, safety issues, drug resistance, and, in some cases, inconvenient routes of administration, which made the scenarios with insufficient health infrastructure settings inconvenient. Pharmaceutical nanocarriers may provide solutions to some of these obstacles, improving the efficacy-safety balance and tolerability to therapeutic interventions. Here, we overview the state of the art of therapeutics for trypanosomatid-caused diseases (including approved drugs and drugs undergoing clinical trials) and the literature on nanolipid pharmaceutical carriers encapsulating approved and non-approved drugs for these diseases. Numerous studies have focused on the obtention and preclinical assessment of lipid nanocarriers, particularly those addressing the two currently most challenging trypanosomatid-caused diseases, Chagas disease, and leishmaniasis. In general, in vitro and in vivo studies suggest that delivering the drugs using such type of nanocarriers could improve the efficacy-safety balance, diminishing cytotoxicity and organ toxicity, especially in leishmaniasis. This constitutes a very relevant outcome, as it opens the possibility to extended treatment regimens and improved compliance. Despite these advances, last-generation nanosystems, such as targeted nanocarriers and hybrid systems, have still not been extensively explored in the field of trypanosomatid-caused conditions and represent promising opportunities for future developments. The potential use of nanotechnology in extended, well-tolerated drug regimens is particularly interesting in the light of recent descriptions of quiescent/dormant stages of Leishmania and Trypanosoma cruzi, which have been linked to therapeutic failure.
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Affiliation(s)
- Giuliana Muraca
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP), La Plata, Argentina
- Administración Nacional de Medicamentos, Alimentos y Tecnología Médica (ANMAT), Buenos Aires, Argentina
| | - Ignacio Rivero Berti
- Laboratorio de Nanobiomateriales, Centro de Investigación y Desarrollo en Fermentaciones Industriales (CINDEFI), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP) -CONICET (CCT La Plata), La Plata, Argentina
| | - María L. Sbaraglini
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP), La Plata, Argentina
| | - Wagner J. Fávaro
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Nelson Durán
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
- Nanomedicine Research Unit (Nanomed), Federal University of ABC (UFABC), Santo André, Brazil
| | - Guillermo R. Castro
- Laboratorio de Nanobiomateriales, Centro de Investigación y Desarrollo en Fermentaciones Industriales (CINDEFI), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP) -CONICET (CCT La Plata), La Plata, Argentina
| | - Alan Talevi
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP), La Plata, Argentina
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Meyer KJ, Meyers DJ, Shapiro TA. Optimal kinetic exposures for classic and candidate antitrypanosomals. J Antimicrob Chemother 2020; 74:2303-2310. [PMID: 31093674 DOI: 10.1093/jac/dkz160] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/18/2019] [Accepted: 03/20/2019] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES Efficacy is determined not only by size, but also by shape, of drug exposure. Here the critical importance of the temporal pattern of drug concentrations (pharmacokinetic profile) is examined for antitrypanosomals in vitro. METHODS An in vitro hollow-fibre cartridge system was used to study contrasting drug profiles with four clinically used agents and two experimental candidates against the deadly parasite Trypanosoma brucei. Artificial kinetics were employed intentionally to favour either high peak concentration or sustained duration of drug. RESULTS Changing the shape of drug exposure significantly impacted drug efficacy. Suramin, melarsoprol and pentamidine were concentration-driven and therefore more efficacious when applied as short-lived high peaks. In contrast, difluoromethylornithine (DFMO) was time-driven, and therefore maximally effective as a constant infusion. Kinetic preference was robust over a wide range of drug exposures. Promising clinical candidates SCYX-7158 (acoziborole) and fexinidazole (parent and sulfone) were concentration-driven, suggesting optimal clinical regimens would involve relatively high but intermittent dosing. CONCLUSIONS Antitrypanosomals have an intrinsic pharmacokinetic driver for optimal efficacy, with important implications for clinical management and future candidate development.
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Affiliation(s)
- Kirsten J Meyer
- Division of Clinical Pharmacology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David J Meyers
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Theresa A Shapiro
- Division of Clinical Pharmacology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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10
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Álvarez-Bardón M, Pérez-Pertejo Y, Ordóñez C, Sepúlveda-Crespo D, Carballeira NM, Tekwani BL, Murugesan S, Martinez-Valladares M, García-Estrada C, Reguera RM, Balaña-Fouce R. Screening Marine Natural Products for New Drug Leads against Trypanosomatids and Malaria. Mar Drugs 2020; 18:E187. [PMID: 32244488 PMCID: PMC7230869 DOI: 10.3390/md18040187] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 02/06/2023] Open
Abstract
Neglected Tropical Diseases (NTD) represent a serious threat to humans, especially for those living in poor or developing countries. Almost one-sixth of the world population is at risk of suffering from these diseases and many thousands die because of NTDs, to which we should add the sanitary, labor and social issues that hinder the economic development of these countries. Protozoan-borne diseases are responsible for more than one million deaths every year. Visceral leishmaniasis, Chagas disease or sleeping sickness are among the most lethal NTDs. Despite not being considered an NTD by the World Health Organization (WHO), malaria must be added to this sinister group. Malaria, caused by the apicomplexan parasite Plasmodium falciparum, is responsible for thousands of deaths each year. The treatment of this disease has been losing effectiveness year after year. Many of the medicines currently in use are obsolete due to their gradual loss of efficacy, their intrinsic toxicity and the emergence of drug resistance or a lack of adherence to treatment. Therefore, there is an urgent and global need for new drugs. Despite this, the scant interest shown by most of the stakeholders involved in the pharmaceutical industry makes our present therapeutic arsenal scarce, and until recently, the search for new drugs has not been seriously addressed. The sources of new drugs for these and other pathologies include natural products, synthetic molecules or repurposing drugs. The most frequent sources of natural products are microorganisms, e.g., bacteria, fungi, yeasts, algae and plants, which are able to synthesize many drugs that are currently in use (e.g. antimicrobials, antitumor, immunosuppressants, etc.). The marine environment is another well-established source of bioactive natural products, with recent applications against parasites, bacteria and other pathogens which affect humans and animals. Drug discovery techniques have rapidly advanced since the beginning of the millennium. The combination of novel techniques that include the genetic modification of pathogens, bioimaging and robotics has given rise to the standardization of High-Performance Screening platforms in the discovery of drugs. These advancements have accelerated the discovery of new chemical entities with antiparasitic effects. This review presents critical updates regarding the use of High-Throughput Screening (HTS) in the discovery of drugs for NTDs transmitted by protozoa, including malaria, and its application in the discovery of new drugs of marine origin.
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Affiliation(s)
- María Álvarez-Bardón
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - Yolanda Pérez-Pertejo
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - César Ordóñez
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - Daniel Sepúlveda-Crespo
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - Nestor M. Carballeira
- Department of Chemistry, University of Puerto Rico, Río Piedras 00925-2537, San Juan, Puerto Rico;
| | - Babu L. Tekwani
- Department of Infectious Diseases, Division of Drug Discovery, Southern Research, Birmingham, AL 35205, USA;
| | - Sankaranarayanan Murugesan
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani Campus, Vidya Vihar, Pilani 333031, India;
| | - Maria Martinez-Valladares
- Department of Animal Health, Instituto de Ganadería de Montaña (CSIC-Universidad de León), Grulleros, 24346 León, Spain;
| | - Carlos García-Estrada
- INBIOTEC (Instituto de Biotecnología de León), Avda. Real 1-Parque Científico de León, 24006 León, Spain;
| | - Rosa M. Reguera
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - Rafael Balaña-Fouce
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
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Santos SS, de Araújo RV, Giarolla J, Seoud OE, Ferreira EI. Searching for drugs for Chagas disease, leishmaniasis and schistosomiasis: a review. Int J Antimicrob Agents 2020; 55:105906. [PMID: 31987883 DOI: 10.1016/j.ijantimicag.2020.105906] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 01/14/2020] [Accepted: 01/18/2020] [Indexed: 12/16/2022]
Abstract
Chagas disease, leishmaniasis and schistosomiasis are neglected diseases (NDs) and are a considerable global challenge. Despite the huge number of people infected, NDs do not create interest from pharmaceutical companies because the associated revenue is generally low. Most of the research on these diseases has been conducted in academic institutions. The chemotherapeutic armamentarium for NDs is scarce and inefficient and better drugs are needed. Researchers have found some promising potential drug candidates using medicinal chemistry and computational approaches. Most of these compounds are synthetic but some are from natural sources or are semi-synthetic. Drug repurposing or repositioning has also been greatly stimulated for NDs. This review considers some potential drug candidates and provides details of their design, discovery and activity.
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Affiliation(s)
- Soraya Silva Santos
- Laboratory of Design and Synthesis of Chemotherapeutics Potentially Active in Neglected Diseases (LAPEN), Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of São Paulo-USP, Avenue Professor Lineu Prestes, 580-Building 13, São Paulo SP, 05508-900, Brazil
| | - Renan Vinicius de Araújo
- Laboratory of Design and Synthesis of Chemotherapeutics Potentially Active in Neglected Diseases (LAPEN), Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of São Paulo-USP, Avenue Professor Lineu Prestes, 580-Building 13, São Paulo SP, 05508-900, Brazil
| | - Jeanine Giarolla
- Laboratory of Design and Synthesis of Chemotherapeutics Potentially Active in Neglected Diseases (LAPEN), Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of São Paulo-USP, Avenue Professor Lineu Prestes, 580-Building 13, São Paulo SP, 05508-900, Brazil
| | - Omar El Seoud
- Laboratory of Design and Synthesis of Chemotherapeutics Potentially Active in Neglected Diseases (LAPEN), Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of São Paulo-USP, Avenue Professor Lineu Prestes, 580-Building 13, São Paulo SP, 05508-900, Brazil
| | - Elizabeth Igne Ferreira
- Laboratory of Design and Synthesis of Chemotherapeutics Potentially Active in Neglected Diseases (LAPEN), Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of São Paulo-USP, Avenue Professor Lineu Prestes, 580-Building 13, São Paulo SP, 05508-900, Brazil.
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12
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Omarch G, Kippie Y, Mentor S, Ebrahim N, Fisher D, Murilla G, Swai H, Dube A. Comparative in vitro transportation of pentamidine across the blood-brain barrier using polycaprolactone nanoparticles and phosphatidylcholine liposomes. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2019; 47:1428-1436. [PMID: 31007068 DOI: 10.1080/21691401.2019.1596923] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Nanoparticles (NPs) have gained importance in addressing drug delivery challenges across biological barriers. Here, we reformulated pentamidine, a drug used to treat Human African Trypanosomiasis (HAT) in polymer based nanoparticles and liposomes and compared their capability to enhance pentamidine penetration across blood brain barrier (BBB). Size, polydispersity index, zeta potential, morphology, pentamidine loading and drug release profiles were determined by various methods. Cytotoxicity was tested against the immortalized mouse brain endothelioma cells over 96 h. Moreover, cells monolayer integrity and transportation ability were examined for 24 h. Pentamidine-loaded polycaprolactone (PCL) nanoparticles had a mean size of 267.58, PDI of 0.25 and zeta potential of -28.1 mV and pentamidine-loaded liposomes had a mean size of 119.61 nm, PDI of 0.25 and zeta potential 11.78. Pentamidine loading was 0.16 µg/mg (w/w) and 0.17 µg/mg (w/w) in PCL NPs and liposomes respectively. PCL nanoparticles and liposomes released 12.13% and 22.21% of pentamidine respectively after 24 h. Liposomes transported 87% of the dose, PCL NPs 66% of the dose and free pentamidine penetration was 63% of the dose. These results suggest that liposomes are comparatively promising nanocarriers for transportation of pentamidine across BBB.
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Affiliation(s)
- Geofrey Omarch
- a School of Life Sciences , The Nelson Mandela African Institution of Science and Technology , Tengeru , Arusha , Tanzania.,b Tanzania Veterinary Laboratory Agency , Temeke , Dar es Salaam , Tanzania
| | - Yunus Kippie
- c School of Pharmacy , University of the Western Cape , Bellville , South Africa
| | - Shireen Mentor
- d School of Life Sciences , University of the Western Cape , Bellville , South Africa
| | - Naushaad Ebrahim
- c School of Pharmacy , University of the Western Cape , Bellville , South Africa
| | - David Fisher
- d School of Life Sciences , University of the Western Cape , Bellville , South Africa
| | - Grace Murilla
- e Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization , Kikuyu, Nairobi , Kenya
| | - Hulda Swai
- a School of Life Sciences , The Nelson Mandela African Institution of Science and Technology , Tengeru , Arusha , Tanzania
| | - Admire Dube
- c School of Pharmacy , University of the Western Cape , Bellville , South Africa
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Bayão TDS, Cupertino MDC, Gomes AP, Siqueira-Batista R. Fexinidazole and Human African Trypanosomiasis: good news for this important neglected tropical disease. Rev Soc Bras Med Trop 2019; 52:e20190176. [DOI: 10.1590/0037-8682-0176-2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 07/18/2019] [Indexed: 05/30/2023] Open
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Pyrih A, Berninger M, Gzella A, Lesyk R, Holzgrabe U. Synthesis and evaluation of antitrypanosomal activity of some thiosemicarbazide derivatives of 1-butyl-6-fluoro-7-morpholino-4-oxo-1,4-dihydroquinoline-3-carboxylic acid. SYNTHETIC COMMUN 2018. [DOI: 10.1080/00397911.2018.1476889] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Andriy Pyrih
- Department of Pharmaceutical, Organic and Bioorganic Chemistry, Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Michael Berninger
- Institute of Pharmacy and Food Chemistry, University Wuerzburg, Am Hubland, Germany
| | - Andrzej Gzella
- Department of Organic Chemistry, Poznan University of Medical Sciences, Poznan, Poland
| | - Roman Lesyk
- Department of Pharmaceutical, Organic and Bioorganic Chemistry, Danylo Halytsky Lviv National Medical University, Lviv, Ukraine
| | - Ulrike Holzgrabe
- Institute of Pharmacy and Food Chemistry, University Wuerzburg, Am Hubland, Germany
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Saarman N, Burak M, Opiro R, Hyseni C, Echodu R, Dion K, Opiyo EA, Dunn AW, Amatulli G, Aksoy S, Caccone A. A spatial genetics approach to inform vector control of tsetse flies ( Glossina fuscipes fuscipes) in Northern Uganda. Ecol Evol 2018; 8:5336-5354. [PMID: 29938057 PMCID: PMC6010828 DOI: 10.1002/ece3.4050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 11/09/2022] Open
Abstract
Tsetse flies (genus Glossina) are the only vector for the parasitic trypanosomes responsible for sleeping sickness and nagana across sub-Saharan Africa. In Uganda, the tsetse fly Glossina fuscipes fuscipes is responsible for transmission of the parasite in 90% of sleeping sickness cases, and co-occurrence of both forms of human-infective trypanosomes makes vector control a priority. We use population genetic data from 38 samples from northern Uganda in a novel methodological pipeline that integrates genetic data, remotely sensed environmental data, and hundreds of field-survey observations. This methodological pipeline identifies isolated habitat by first identifying environmental parameters correlated with genetic differentiation, second, predicting spatial connectivity using field-survey observations and the most predictive environmental parameter(s), and third, overlaying the connectivity surface onto a habitat suitability map. Results from this pipeline indicated that net photosynthesis was the strongest predictor of genetic differentiation in G. f. fuscipes in northern Uganda. The resulting connectivity surface identified a large area of well-connected habitat in northwestern Uganda, and twenty-four isolated patches on the northeastern margin of the G. f. fuscipes distribution. We tested this novel methodological pipeline by completing an ad hoc sample and genetic screen of G. f. fuscipes samples from a model-predicted isolated patch, and evaluated whether the ad hoc sample was in fact as genetically isolated as predicted. Results indicated that genetic isolation of the ad hoc sample was as genetically isolated as predicted, with differentiation well above estimates made in samples from within well-connected habitat separated by similar geographic distances. This work has important practical implications for the control of tsetse and other disease vectors, because it provides a way to identify isolated populations where it will be safer and easier to implement vector control and that should be prioritized as study sites during the development and improvement of vector control methods.
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Affiliation(s)
- Norah Saarman
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
| | - Mary Burak
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
| | - Robert Opiro
- Department of BiologyFaculty of ScienceGulu UniversityGuluLaroo DivisionUganda
| | - Chaz Hyseni
- Department of BiologyUniversity of MississippiOxfordMassachusetts
| | - Richard Echodu
- Department of BiologyFaculty of ScienceGulu UniversityGuluLaroo DivisionUganda
| | - Kirstin Dion
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
| | - Elizabeth A. Opiyo
- Department of BiologyFaculty of ScienceGulu UniversityGuluLaroo DivisionUganda
| | - Augustine W. Dunn
- Division of Genetics and GenomicsBoston Children's HospitalBostonMassachusetts
| | - Giuseppe Amatulli
- Department of GeoComputation and Spatial ScienceYale School of Forestry and Environmental StudiesNew HavenConnecticut
| | - Serap Aksoy
- Department of Epidemiology of Microbial DiseasesYale School of Public HealthNew HavenConnecticut
| | - Adalgisa Caccone
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
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Franco J, Scarone L, Comini MA. Drugs and Drug Resistance in African and American Trypanosomiasis. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2018. [DOI: 10.1016/bs.armc.2018.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Novel Therapeutic Targets for Human African Trypanosomiasis. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2017. [DOI: 10.1007/s40506-017-0120-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Patrick DA, Gillespie JR, McQueen J, Hulverson MA, Ranade RM, Creason SA, Herbst ZM, Gelb MH, Buckner FS, Tidwell RR. Urea Derivatives of 2-Aryl-benzothiazol-5-amines: A New Class of Potential Drugs for Human African Trypanosomiasis. J Med Chem 2016; 60:957-971. [PMID: 27992217 DOI: 10.1021/acs.jmedchem.6b01163] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A previous publication from this lab (Patrick, et al. Bioorg. Med. Chem. 2016, 24 , 2451 - 2465 ) explored the antitrypanosomal activities of novel derivatives of 2-(2-benzamido)ethyl-4-phenylthiazole (1), which had been identified as a hit against Trypanosoma brucei, the causative agent of human African trypanosomiasis. While a number of these compounds, particularly the urea analogues, were quite potent, these molecules as a whole exhibited poor metabolic stability. The present work describes the synthesis of 65 new analogues arising from medicinal chemistry optimization at different sites on the molecule. The most promising compounds were the urea derivatives of 2-aryl-benzothiazol-5-amines. One such analogue, (S)-2-(3,4-difluorophenyl)-5-(3-fluoro-N-pyrrolidylamido)benzothiazole (57) was chosen for in vivo efficacy studies based upon in vitro activity, metabolic stability, and brain penetration. This compound attained 5/5 cures in murine models of both early and late stage human African trypanosomiasis, representing a new lead for the development of drugs to combat this neglected disease.
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Affiliation(s)
- Donald A Patrick
- Department of Pathology and Laboratory Medicine, University of North Carolina , Chapel Hill, North Carolina 27599, United States
| | | | | | | | | | | | | | | | | | - Richard R Tidwell
- Department of Pathology and Laboratory Medicine, University of North Carolina , Chapel Hill, North Carolina 27599, United States
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de Silva Rodrigues JH, Stein J, Strauss M, Rivarola HW, Ueda-Nakamura T, Nakamura CV, Duszenko M. Clomipramine kills Trypanosoma brucei by apoptosis. Int J Med Microbiol 2016; 306:196-205. [DOI: 10.1016/j.ijmm.2016.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 03/07/2016] [Accepted: 03/28/2016] [Indexed: 12/31/2022] Open
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Patrick DA, Wenzler T, Yang S, Weiser PT, Wang MZ, Brun R, Tidwell RR. Synthesis of novel amide and urea derivatives of thiazol-2-ethylamines and their activity against Trypanosoma brucei rhodesiense. Bioorg Med Chem 2016; 24:2451-2465. [PMID: 27102161 PMCID: PMC4862372 DOI: 10.1016/j.bmc.2016.04.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 03/24/2016] [Accepted: 04/01/2016] [Indexed: 11/24/2022]
Abstract
2-(2-Benzamido)ethyl-4-phenylthiazole (1) was one of 1035 molecules (grouped into 115 distinct scaffolds) found to be inhibitory to Trypanosoma brucei, the pathogen causing human African trypanosomiasis, at concentrations below 3.6μM and non-toxic to mammalian (Huh7) cells in a phenotypic high-throughput screen of a 700,000 compound library performed by the Genomics Institute of the Novartis Research Foundation (GNF). Compound 1 and 72 analogues were synthesized in this lab by one of two general pathways. These plus 10 commercially available analogues were tested against T. brucei rhodesiense STIB900 and L6 rat myoblast cells (for cytotoxicity) in vitro. Forty-four derivatives were more potent than 1, including eight with IC50 values below 100nM. The most potent and most selective for the parasite was the urea analogue 2-(2-piperidin-1-ylamido)ethyl-4-(3-fluorophenyl)thiazole (70, IC50=9nM, SI>18,000). None of 33 compounds tested were able to cure mice infected with the parasite; however, seven compounds caused temporary reductions of parasitemia (⩾97%) but with subsequent relapses. The lack of in vivo efficacy was at least partially due to their poor metabolic stability, as demonstrated by the short half-lives of 15 analogues against mouse and human liver microsomes.
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Affiliation(s)
- Donald A Patrick
- University of North Carolina, Pathology & Laboratory Medicine, 805 Brinkhous-Bullitt Bldg, CB7525, Chapel Hill, NC 27599-7525, USA
| | - Tanja Wenzler
- Swiss Tropical and Public Health Institute, Socinstrasse 57, CH-4002 Basel, Switzerland; University of Basel, 4003 Basel, Switzerland
| | - Sihyung Yang
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Patrick T Weiser
- University of North Carolina, Pathology & Laboratory Medicine, 805 Brinkhous-Bullitt Bldg, CB7525, Chapel Hill, NC 27599-7525, USA
| | - Michael Zhuo Wang
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Reto Brun
- Swiss Tropical and Public Health Institute, Socinstrasse 57, CH-4002 Basel, Switzerland; University of Basel, 4003 Basel, Switzerland
| | - Richard R Tidwell
- University of North Carolina, Pathology & Laboratory Medicine, 805 Brinkhous-Bullitt Bldg, CB7525, Chapel Hill, NC 27599-7525, USA.
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Screening North American plant extracts in vitro against Trypanosoma brucei for discovery of new antitrypanosomal drug leads. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2016; 16:131. [PMID: 27193901 PMCID: PMC4870785 DOI: 10.1186/s12906-016-1122-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/13/2016] [Indexed: 12/04/2022]
Abstract
Background Human African Trypanosomiasis (HAT) is a protozoan parasitic disease caused by Trypanosoma brucei. The disease is endemic in regions of sub-Saharan Africa, covering 36 countries and more than 60 million people at the risk. Only few drugs are available for the treatment of HAT. Current drugs suffer from severe toxicities and require intramuscular or intravenous administrations. The situation is further aggravated due to the emergence of drug resistance. There is an urgent need of new drugs that are effective orally against both stages of HAT. Natural products offer an unmatched source for bioactive molecules with new chemotypes. Methods The extracts prepared from 522 plants collected from various parts of the North America were screened in vitro against blood stage trypamastigote forms of T. brucei. Active extracts were further screened at concentrations ranging from 10 to 0.4 μg/mL. Active extracts were also investigated for toxicity in Differentiated THP1 cells at 10 μg/mL concentration. The results were computed for dose–response analysis and determination of IC50/IC90 values. Results A significant number (150) of extracts showed >90 % inhibition of growth of trypomastigote blood forms of T. brucei in primary screening at 20 μg/mL concentration. The active extracts were further investigated for dose–response inhibition of T. brucei growth. The antitrypansomal activity of 125 plant extracts was confirmed with IC50 < 10 μg/mL. None of these active extracts showed toxicity against differentiated THP1 cells. Eight plants extracts namely, Alnus rubra, Hoita macrostachya, Sabal minor, Syzygium aqueum, Hamamelis virginiana, Coccoloba pubescens, Rhus integrifolia and Nuphar luteum were identified as highly potent antitrypanosomal extracts with IC50 values <1 μg/mL. Conclusions Limited phytochemical and pharmacological reports are available for the lead plant extracts with potent antitrypanosomal activity. Follow up evaluation of these plant extracts is likely to yield new antitrypanosomal drug-leads or alternate medicines for treatment of HAT. Electronic supplementary material The online version of this article (doi:10.1186/s12906-016-1122-0) contains supplementary material, which is available to authorized users.
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Bonnet J, Boudot C, Courtioux B. Overview of the Diagnostic Methods Used in the Field for Human African Trypanosomiasis: What Could Change in the Next Years? BIOMED RESEARCH INTERNATIONAL 2015; 2015:583262. [PMID: 26504815 PMCID: PMC4609347 DOI: 10.1155/2015/583262] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/19/2015] [Accepted: 07/02/2015] [Indexed: 11/18/2022]
Abstract
Sleeping sickness is a parasitic infection caused by two species of trypanosomes (Trypanosoma brucei gambiense and rhodesiense), transmitted by the tsetse fly. The disease eventually affects the central nervous system, resulting in severe neurological symptoms. Without treatment, death is inevitable. During the first stage of the disease, infected patients are mildly symptomatic and early detection of infection allows safer treatment (administered on an outpatient basis) which can avoid death; routine screening of the exposed population is necessary, especially in areas of high endemicity. The current therapeutic treatment of this disease, especially in stage 2, can cause complications and requires a clinical surveillance for several days. A good stage diagnosis of the disease is the cornerstone for delivering the adequate treatment. The task faced by the medical personnel is further complicated by the lack of support from local health infrastructure, which is at best weak, but often nonexistent. Therefore it is crucial to look for new more efficient technics for the diagnosis of stage which are also best suited to use in the field, in areas not possessing high-level health facilities. This review, after an overview of the disease, summarizes the current diagnosis procedures and presents the advances in the field.
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Affiliation(s)
- Julien Bonnet
- INSERM, U1094, Tropical Neuroepidemiology, Limoges, France
- UMR_S 1094, Tropical Neuroepidemiology, Institute of Neuroepidemiology and Tropical Neurology, Université de Limoges, CNRS FR 3503 GEIST, 87000 Limoges, France
| | - Clotilde Boudot
- INSERM, U1094, Tropical Neuroepidemiology, Limoges, France
- UMR_S 1094, Tropical Neuroepidemiology, Institute of Neuroepidemiology and Tropical Neurology, Université de Limoges, CNRS FR 3503 GEIST, 87000 Limoges, France
| | - Bertrand Courtioux
- INSERM, U1094, Tropical Neuroepidemiology, Limoges, France
- UMR_S 1094, Tropical Neuroepidemiology, Institute of Neuroepidemiology and Tropical Neurology, Université de Limoges, CNRS FR 3503 GEIST, 87000 Limoges, France
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Keil A, Frese-Schaper M, Steiner SK, Körner M, Schmid RA, Frese S. The Topoisomerase I Inhibitor Irinotecan and the Tyrosyl-DNA Phosphodiesterase 1 Inhibitor Furamidine Synergistically Suppress Murine Lupus Nephritis. Arthritis Rheumatol 2015; 67:1858-67. [PMID: 25779651 DOI: 10.1002/art.39119] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/12/2015] [Indexed: 01/12/2023]
Abstract
OBJECTIVE The treatment of lupus nephritis is still an unmet medical need requiring new therapeutic approaches. Our group found recently that irinotecan, an inhibitor of topoisomerase I (topo I), reversed proteinuria and prolonged survival in mice with advanced lupus nephritis. While irinotecan is known to stabilize the complex of topo I and DNA, the enzyme tyrosyl-DNA phosphodiesterase 1 (TDP-1) functions in an opposing manner by releasing topo I from DNA. Therefore, we undertook this study to test whether the TDP-1 inhibitor furamidine has an additional effect on lupus nephritis when used in combination with irinotecan. METHODS NZB/NZW mice were treated with low-dose irinotecan and furamidine either alone or in combination beginning at age 26 weeks. DNA relaxation was visualized using gel electrophoresis. Binding of anti-double-stranded DNA (anti-dsDNA) antibodies to DNA modified by topo I, TDP-1, and the topo I inhibitor camptothecin was determined by enzyme-linked immunosorbent assay. RESULTS Compared to treatment with either agent alone, simultaneous treatment with low-dose irinotecan and furamidine significantly improved survival of NZB/NZW mice. Similar to what has been previously shown for irinotecan alone, the combination treatment did not change the levels of anti-dsDNA antibodies. In vitro, recombinant TDP-1 increased topo I-mediated DNA relaxation, resulting in enhanced binding of anti-dsDNA antibodies. In combination with topo I and camptothecin, TDP-1 reversed the inhibitory effects of camptothecin on DNA relaxation and anti-dsDNA binding. CONCLUSION Affecting DNA relaxation by the enzymes topo I and TDP-1 and their inhibitors may be a promising approach for the development of new targeted therapies for systemic lupus erythematosus.
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Mpanya A, Hendrickx D, Baloji S, Lumbala C, da Luz RI, Boelaert M, Lutumba P. From health advice to taboo: community perspectives on the treatment of sleeping sickness in the Democratic Republic of Congo, a qualitative study. PLoS Negl Trop Dis 2015; 9:e0003686. [PMID: 25856578 PMCID: PMC4391751 DOI: 10.1371/journal.pntd.0003686] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 03/07/2015] [Indexed: 12/14/2022] Open
Abstract
Background Socio-cultural and economic factors constitute real barriers for uptake of screening and treatment of Human African Trypanosomiasis (HAT) in the Democratic Republic of Congo (DRC). Better understanding and addressing these barriers may enhance the effectiveness of HAT control. Methods We performed a qualitative study consisting of semi-structured interviews and focus group discussions in the Bandundu and Kasaï Oriental provinces, two provinces lagging behind in the HAT elimination effort. Our study population included current and former HAT patients, as well as healthcare providers and program managers of the national HAT control program. All interviews and discussions were voice recorded on a digital device and data were analysed with the ATLAS.ti software. Findings Health workers and community members quoted a number of prohibitions that have to be respected for six months after HAT treatment: no work, no sexual intercourse, no hot food, not walking in the sun. Violating these restrictions is believed to cause serious, and sometimes deadly, complications. These strong prohibitions are well-known by the community and lead some people to avoid HAT screening campaigns, for fear of having to observe such taboos in case of diagnosis. Discussion The restrictions originally aimed to mitigate the severe adverse effects of the melarsoprol regimen, but are not evidence-based and became obsolete with the new safer drugs. Correct health information regarding HAT treatment is essential. Health providers should address the perspective of the community in a constant dialogue to keep abreast of unintended transformations of meaning. The principal strategy for the control of HAT is based on early detection and prompt treatment of identified cases. A range of taboos are associated with HAT treatment in DRC. The origin of these taboos is not well understood. These taboos constitute major issues for patients and their families, lead to huge social pressure from the community on HAT patients and add in themselves to the burden caused by the disease itself. The aim of this study is to document the origin of these taboos and other cultural factors that are associated with HAT treatment, since an improved understanding of these factors and their implications may lead to strategies for improved community adherence to HAT screening and treatment. We found that the taboos are associated with the melarsoprol toxicity and have been established empirically following past interactions between healthcare providers and communities. The prohibitions started as simple instructions provided by healthcare providers about the management of HAT cases, but over time evolved into the community-based taboos we observe now. Use of less toxic treatment alternatives for HAT, dissemination of correct information regarding HAT treatment regimens, possible occurrence of adverse events and their cause would be beneficial to HAT control.
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Affiliation(s)
- Alain Mpanya
- Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of Congo
- Institute of Tropical Medicine, Antwerp, Belgium
- * E-mail:
| | - David Hendrickx
- Institute of Tropical Medicine, Antwerp, Belgium
- Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia
| | - Sylvain Baloji
- Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of Congo
- Université Pédagogique Nationale, Kinshasa, Democratic Republic of Congo
| | - Crispin Lumbala
- Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Kinshasa, Democratic Republic of Congo
| | | | | | - Pascal Lutumba
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of Congo
- Université de Kinshasa, Kinshasa, Democratic Republic of Congo
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Increased acute immune response during the meningo-encephalitic stage of Trypanosoma brucei rhodesiense sleeping sickness compared to Trypanosoma brucei gambiense. TRANSLATIONAL PROTEOMICS 2015. [DOI: 10.1016/j.trprot.2014.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Sternberg JM, Gierliński M, Biéler S, Ferguson MAJ, Ndung'u JM. Evaluation of the diagnostic accuracy of prototype rapid tests for human African trypanosomiasis. PLoS Negl Trop Dis 2014; 8:e3373. [PMID: 25521120 PMCID: PMC4270746 DOI: 10.1371/journal.pntd.0003373] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 10/26/2014] [Indexed: 11/19/2022] Open
Abstract
Background Diagnosis of human African trypanosomiasis (HAT) remains a challenge both for active screening, which is critical in control of the disease, and in the point-of-care scenario where early and accurate diagnosis is essential. Recently, the first field deployment of a lateral flow rapid diagnostic test (RDT) for HAT, “SD BIOLINE HAT” has taken place. In this study, we evaluated the performance of “SD BIOLINE HAT” and two new prototype RDTs. Methodology/Principal Findings The performance of “SD BIOLINE HAT” and 2 prototype RDTs was tested using archived plasma from 250 Trypanosoma brucei gambiense patients, and 250 endemic controls. As well as comparison of the sensitivity and specificity of each device, the performance of individual antigens was assessed and the hypothetical performance of novel antigen combinations extrapolated. Neither of the prototype devices were inferior in sensitivity or specificity to “SD BIOLINE HAT” (sensitivity 0.82±0.01, specificity 0.97±0.01, 95% CI) at the 5% margins, while one of the devices (BBI) had significantly superior sensitivity (0.88±0.03). Analysis of the performance of individual antigens was used to model new antigen combinations to be explored in development of the next generation of HAT RDTs. The modelling showed that an RDT using two recombinant antigens (rLiTat1.5 and rISG65) would give a performance similar to the best devices in this study, and would also offer the most robust performance under deteriorating field conditions. Conclusions/Significance Both “SD BIOLINE HAT” and the prototype devices performed comparably well to one another and also to the published performance range of the card agglutination test for trypanosomiasis in sensitivity and specificity. The performance of individual antigens enabled us to predict that an all-recombinant antigen RDT can be developed with an accuracy equivalent to “ SD BIOLINE HAT.” Such an RDT would have advantages in simplified manufacture, lower unit cost and assured reproducibility. The most prevalent species of trypanosome causing human African trypanosomiasis (HAT), Trypanosoma brucei gambiense, presents a diagnostic challenge. While early diagnosis is essential for effective treatment and also to control transmission, symptoms are non-specific and parasitological diagnosis is laborious and technically difficult. Screening for HAT suspects has until now been done using the card agglutination test for trypanosomiasis (CATT), which requires a cold chain and equipment, making it difficult to deploy. Thus there is an urgent need for sensitive point of care diagnostic tests that are suitable for use in rural areas in terms of stability, simplicity and cost. We describe the evaluation of 3 rapid diagnostic tests (RDTs) for HAT based on lateral flow devices that detect antibodies against defined parasite antigens in blood samples. We demonstrate that the SD BIOLINE HAT RDT currently being deployed in HAT endemic regions, as well as two new prototype devices, are accurate in screening for HAT. By analysing the sensitivity of each of the antigens used in the devices tested, we predict that a highly sensitive RDT based on recombinant antigens can be developed. An all-recombinant antigen RDT offers significant benefits in manufacturing reproducibility and cost, and would dramatically simplify HAT diagnosis.
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Affiliation(s)
- Jeremy M. Sternberg
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
- * E-mail:
| | - Marek Gierliński
- College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sylvain Biéler
- Foundation for Innovative New Diagnostics (FIND) Campus Biotech, Geneva, Switzerland
| | | | - Joseph M. Ndung'u
- Foundation for Innovative New Diagnostics (FIND) Campus Biotech, Geneva, Switzerland
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Murungi EK, Kariithi HM, Adunga V, Obonyo M, Christoffels A. Evolution and Structural Analyses of Glossina morsitans (Diptera; Glossinidae) Tetraspanins. INSECTS 2014; 5:885-908. [PMID: 26462947 PMCID: PMC4592607 DOI: 10.3390/insects5040885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 10/23/2014] [Accepted: 11/02/2014] [Indexed: 12/25/2022]
Abstract
Tetraspanins are important conserved integral membrane proteins expressed in many organisms. Although there is limited knowledge about the full repertoire, evolution and structural characteristics of individual members in various organisms, data obtained so far show that tetraspanins play major roles in membrane biology, visual processing, memory, olfactory signal processing, and mechanosensory antennal inputs. Thus, these proteins are potential targets for control of insect pests. Here, we report that the genome of the tsetse fly, Glossina morsitans (Diptera: Glossinidae) encodes at least seventeen tetraspanins (GmTsps), all containing the signature features found in the tetraspanin superfamily members. Whereas six of the GmTsps have been previously reported, eleven could be classified as novel because their amino acid sequences do not map to characterized tetraspanins in the available protein data bases. We present a model of the GmTsps by using GmTsp42Ed, whose presence and expression has been recently detected by transcriptomics and proteomics analyses of G. morsitans. Phylogenetically, the identified GmTsps segregate into three major clusters. Structurally, the GmTsps are largely similar to vertebrate tetraspanins. In view of the exploitation of tetraspanins by organisms for survival, these proteins could be targeted using specific antibodies, recombinant large extracellular loop (LEL) domains, small-molecule mimetics and siRNAs as potential novel and efficacious putative targets to combat African trypanosomiasis by killing the tsetse fly vector.
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Affiliation(s)
- Edwin K Murungi
- South African National Bioinformatics Institute (SANBI), University of the Western Cape, Private Bag X79, Bellville, Cape Town 7535, South Africa.
| | - Henry M Kariithi
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization (KALRO), P.O. Box 57811, Kaptagat Rd, Nairobi 00200, Kenya.
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands.
| | - Vincent Adunga
- Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, Egerton 20115, Kenya.
| | - Meshack Obonyo
- Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, Egerton 20115, Kenya.
| | - Alan Christoffels
- South African National Bioinformatics Institute (SANBI), University of the Western Cape, Private Bag X79, Bellville, Cape Town 7535, South Africa.
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Trypanosoma brucei eflornithine transporter AAT6 is a low-affinity low-selective transporter for neutral amino acids. Biochem J 2014; 463:9-18. [PMID: 24988048 DOI: 10.1042/bj20140719] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Amino acid transporters are crucial for parasite survival since the cellular metabolism of parasitic protozoa depends on the up-take of exogenous amino acids. Amino acid transporters are also of high pharmacological relevance because they may mediate uptake of toxic amino acid analogues. In the present study we show that the eflornithine transporter AAT6 from Trypanosoma brucei (TbAAT6) mediates growth on neutral amino acids when expressed in Saccharomyces cerevisiae mutants. The transport was electrogenic and further analysed in Xenopus laevis oocytes. Neutral amino acids, proline analogues, eflornithine and acivicin induced inward currents. For proline, glycine and tryptophan the apparent affinities and maximal transport rates increased with more negative membrane potentials. Proline-induced currents were dependent on pH, but not on sodium. Although proline represents the primary energy source of T. brucei in the tsetse fly, down-regulation of TbAAT6-expression by RNAi showed that in culture TbAAT6 is not essential for growth of procyclic form trypanosomes in the presence of glucose or proline as energy source. TbAAT6-RNAi lines of both bloodstream and procyclic form trypanosomes showed reduced susceptibility to eflornithine, whereas the sensitivity to acivicin remained unchanged, indicating that acivicin enters the cell by more than one transporter.
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Mackey TK, Liang BA, Cuomo R, Hafen R, Brouwer KC, Lee DE. Emerging and reemerging neglected tropical diseases: a review of key characteristics, risk factors, and the policy and innovation environment. Clin Microbiol Rev 2014; 27:949-79. [PMID: 25278579 PMCID: PMC4187634 DOI: 10.1128/cmr.00045-14] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern.
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Affiliation(s)
- Tim K Mackey
- Department of Anesthesiology, University of California, San Diego, School of Medicine, San Diego, California, USA Division of Global Public Health, University of California, San Diego, Department of Medicine, San Diego, California, USA
| | - Bryan A Liang
- Department of Anesthesiology, University of California, San Diego, School of Medicine, San Diego, California, USA
| | - Raphael Cuomo
- Joint Doctoral Program in Global Public Health, University of California, San Diego, and San Diego State University, San Diego, California, USA
| | - Ryan Hafen
- Department of Anesthesiology, University of California, San Diego, School of Medicine, San Diego, California, USA Internal Medicine, University of California, San Diego, School of Medicine, San Diego, California, USA
| | - Kimberly C Brouwer
- Division of Global Public Health, University of California, San Diego, Department of Medicine, San Diego, California, USA
| | - Daniel E Lee
- Department of Anesthesiology, University of California, San Diego, School of Medicine, San Diego, California, USA Pediatrics Department, University of California, San Diego, School of Medicine, San Diego, California, USA
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Balaña-Fouce R, Alvarez-Velilla R, Fernández-Prada C, García-Estrada C, Reguera RM. Trypanosomatids topoisomerase re-visited. New structural findings and role in drug discovery. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2014; 4:326-37. [PMID: 25516844 PMCID: PMC4266802 DOI: 10.1016/j.ijpddr.2014.07.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
There is an urgent need of new treatments against trypanosomatids-borne diseases. DNA topoisomerases are pointed as potential drug targets against unicellular parasites. Trypanosomatids have a full set of DNA topoisomerases in both nucleus and kinetoplast. TopII and TopIII are located in the kinetoplast and fully involved in kDNA replication. Tritryps TopIB differ in structure from mammalian’s pointing to an attractive target.
The Trypanosomatidae family, composed of unicellular parasites, causes severe vector-borne diseases that afflict human populations worldwide. Chagas disease, sleeping sickness, as well as different sorts of leishmaniases are amongst the most important infectious diseases produced by Trypanosoma cruzi, Trypanosoma brucei and Leishmania spp., respectively. All these infections are closely related to weak health care services in low-income populations of less developed and least economically developed countries. Search for new therapeutic targets in order to hit these pathogens is of paramount priority, as no effective vaccine is currently in use against any of these parasites. Furthermore, present-day chemotherapy comprises old-fashioned drugs full of important side effects. Besides, they are prone to produce tolerance and resistance as a consequence of their continuous use for decades. DNA topoisomerases (Top) are ubiquitous enzymes responsible for solving the torsional tensions caused during replication and transcription processes, as well as in maintaining genomic stability during DNA recombination. As the inhibition of these enzymes produces cell arrest and triggers cell death, Top inhibitors are among the most effective and most widely used drugs in both cancer and antibacterial therapies. Top relaxation and decatenation activities, which are based on a common nicking–closing cycle involving one or both DNA strands, have been pointed as a promising drug target. Specific inhibitors that bind to the interface of DNA-Top complexes can stabilize Top-mediated transient DNA breaks. In addition, important structural differences have been found between Tops from the Trypanosomatidae family members and Tops from the host. Such dissimilarities make these proteins very interesting for drug design and molecular intervention. The present review is a critical update of the last findings regarding trypanosomatid’s Tops, their new structural features, their involvement both in the physiology and virulence of these parasites, as well as their use as promising targets for drug discovery.
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Affiliation(s)
- Rafael Balaña-Fouce
- Departamento de Ciencias Biomédicas, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Raquel Alvarez-Velilla
- Departamento de Ciencias Biomédicas, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | | | - Carlos García-Estrada
- Departamento de Ciencias Biomédicas, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Rosa M Reguera
- Departamento de Ciencias Biomédicas, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
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In vitro and in vivo evaluation of 28DAP010, a novel diamidine for treatment of second-stage African sleeping sickness. Antimicrob Agents Chemother 2014; 58:4452-63. [PMID: 24867978 DOI: 10.1128/aac.02309-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
African sleeping sickness is a neglected tropical disease transmitted by tsetse flies. New and better drugs are still needed especially for its second stage, which is fatal if untreated. 28DAP010, a dipyridylbenzene analogue of DB829, is the second simple diamidine found to cure mice with central nervous system infections by a parenteral route of administration. 28DAP010 showed efficacy similar to that of DB829 in dose-response studies in mouse models of first- and second-stage African sleeping sickness. The in vitro time to kill, determined by microcalorimetry, and the parasite clearance time in mice were shorter for 28DAP010 than for DB829. No cross-resistance was observed between 28DAP010 and pentamidine on the tested Trypanosoma brucei gambiense isolates from melarsoprol-refractory patients. 28DAP010 is the second promising preclinical candidate among the diamidines for the treatment of second-stage African sleeping sickness.
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Hackett F, Berrang Ford L, Fèvre E, Simarro P. Incorporating scale dependence in disease burden estimates: the case of human African trypanosomiasis in Uganda. PLoS Negl Trop Dis 2014; 8:e2704. [PMID: 24551264 PMCID: PMC3923749 DOI: 10.1371/journal.pntd.0002704] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 01/03/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The WHO has established the disability-adjusted life year (DALY) as a metric for measuring the burden of human disease and injury globally. However, most DALY estimates have been calculated as national totals. We mapped spatial variation in the burden of human African trypanosomiasis (HAT) in Uganda for the years 2000-2009. This represents the first geographically delimited estimation of HAT disease burden at the sub-country scale. METHODOLOGY/PRINCIPAL FINDINGS Disability-adjusted life-year (DALY) totals for HAT were estimated based on modelled age and mortality distributions, mapped using Geographic Information Systems (GIS) software, and summarised by parish and district. While the national total burden of HAT is low relative to other conditions, high-impact districts in Uganda had DALY rates comparable to the national burden rates for major infectious diseases. The calculated average national DALY rate for 2000-2009 was 486.3 DALYs/100 000 persons/year, whereas three districts afflicted by rhodesiense HAT in southeastern Uganda had burden rates above 5000 DALYs/100 000 persons/year, comparable to national GBD 2004 average burden rates for malaria and HIV/AIDS. CONCLUSIONS/SIGNIFICANCE These results provide updated and improved estimates of HAT burden across Uganda, taking into account sensitivity to under-reporting. Our results highlight the critical importance of spatial scale in disease burden analyses. National aggregations of disease burden have resulted in an implied bias against highly focal diseases for which geographically targeted interventions may be feasible and cost-effective. This has significant implications for the use of DALY estimates to prioritize disease interventions and inform cost-benefit analyses.
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Affiliation(s)
- Finola Hackett
- Department of Geography, McGill University, Montreal, Quebec, Canada
| | - Lea Berrang Ford
- Department of Geography, McGill University, Montreal, Quebec, Canada
| | - Eric Fèvre
- Veterinary and Infectious Diseases, Institute of Infection and Global Health, University of Liverpool, Neston, United Kingdom
| | - Pere Simarro
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
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Bottieau E, Vekemans M, Van Gompel A. Therapy of vector-borne protozoan infections in nonendemic settings. Expert Rev Anti Infect Ther 2014; 9:583-608. [DOI: 10.1586/eri.11.32] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Holzmuller P, Grébaut P, Semballa S, Gonzatti MI, Geiger A. Proteomics: a new way to improve human African trypanosomiasis diagnosis? Expert Rev Proteomics 2014; 10:289-301. [DOI: 10.1586/epr.13.14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Brimacombe KR, Walsh MJ, Liu L, Vásquez-Valdivieso MG, Morgan HP, McNae I, Fothergill-Gilmore LA, Michels PAM, Auld DS, Simeonov A, Walkinshaw MD, Shen M, Boxer MB. Identification of ML251, a Potent Inhibitor of T. brucei and T. cruzi Phosphofructokinase. ACS Med Chem Lett 2014; 5:12-7. [PMID: 24900769 DOI: 10.1021/ml400259d] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 10/30/2013] [Indexed: 11/30/2022] Open
Abstract
Human African Trypanosomiasis (HAT) is a severe, often fatal disease caused by the parasitic protist Trypanosoma brucei. The glycolytic pathway has been identified as the sole mechanism for ATP generation in the infective stage of these organisms, and several glycolytic enzymes, phosphofructokinase (PFK) in particular, have shown promise as potential drug targets. Herein, we describe the discovery of ML251, a novel nanomolar inhibitor of T. brucei PFK, and the structure-activity relationships within the series.
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Affiliation(s)
- Kyle R. Brimacombe
- National
Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, Maryland 20850, United States
| | - Martin J. Walsh
- National
Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, Maryland 20850, United States
| | - Li Liu
- National
Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, Maryland 20850, United States
| | - Montserrat G. Vásquez-Valdivieso
- Centre
for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings,
Mayfield Road, Edinburgh EH9 3JR, U.K
| | - Hugh P. Morgan
- Centre
for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings,
Mayfield Road, Edinburgh EH9 3JR, U.K
| | - Iain McNae
- Centre
for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings,
Mayfield Road, Edinburgh EH9 3JR, U.K
| | - Linda A. Fothergill-Gilmore
- Centre
for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings,
Mayfield Road, Edinburgh EH9 3JR, U.K
| | - Paul A. M. Michels
- Research
Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Université catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium
| | - Douglas S. Auld
- National
Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, Maryland 20850, United States
| | - Anton Simeonov
- National
Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, Maryland 20850, United States
| | - Malcolm D. Walkinshaw
- Centre
for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings,
Mayfield Road, Edinburgh EH9 3JR, U.K
| | - Min Shen
- National
Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, Maryland 20850, United States
| | - Matthew B. Boxer
- National
Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, Maryland 20850, United States
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Abstract
The potential of flavoproteins as targets of pharmacological treatments is immense. In this review we present an overview of the current research progress on medical interventions based on flavoproteins with a special emphasis on cancer, infectious diseases, and neurological disorders.
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Affiliation(s)
- Esther Jortzik
- Interdisciplinary Research Center, Justus Liebig University, Giessen, Germany
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Antiprotozoal activity of dicationic 3,5-diphenylisoxazoles, their prodrugs and aza-analogues. Bioorg Med Chem 2013; 22:559-76. [PMID: 24268543 DOI: 10.1016/j.bmc.2013.10.050] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/21/2013] [Accepted: 10/29/2013] [Indexed: 11/23/2022]
Abstract
Fifty novel prodrugs and aza-analogues of 3,5-bis(4-amidinophenyl)isoxazole and its derivatives were prepared. Eighteen of the 24 aza-analogues exhibited IC₅₀ values below 25 nM against Trypanosoma brucei rhodesiense or Plasmodium falciparum. Six compounds had antitrypanosomal IC₅₀ values below 10 nM. Twelve analogues showed similar antiplasmodial activities, including three with sub-nanomolar potencies. Forty-four diamidines (including 16 aza-analogues) and the 26 prodrugs were evaluated for efficacy in mice infected with T. b. rhodesiense STIB900. Six diamidines cured 4/4 mice at daily 5 mg/kg intraperitoneal doses for 4 days, giving results far superior to pentamidine and furamidine. One prodrug attained 3/4 cures at daily 25 mg/kg oral doses for 4 days.
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Pizarro JC, Hills T, Senisterra G, Wernimont AK, Mackenzie C, Norcross NR, Ferguson MAJ, Wyatt PG, Gilbert IH, Hui R. Exploring the Trypanosoma brucei Hsp83 potential as a target for structure guided drug design. PLoS Negl Trop Dis 2013; 7:e2492. [PMID: 24147171 PMCID: PMC3798429 DOI: 10.1371/journal.pntd.0002492] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 09/09/2013] [Indexed: 01/08/2023] Open
Abstract
Human African trypanosomiasis is a neglected parasitic disease that is fatal if untreated. The current drugs available to eliminate the causative agent Trypanosoma brucei have multiple liabilities, including toxicity, increasing problems due to treatment failure and limited efficacy. There are two approaches to discover novel antimicrobial drugs - whole-cell screening and target-based discovery. In the latter case, there is a need to identify and validate novel drug targets in Trypanosoma parasites. The heat shock proteins (Hsp), while best known as cancer targets with a number of drug candidates in clinical development, are a family of emerging targets for infectious diseases. In this paper, we report the exploration of T. brucei Hsp83 – a homolog of human Hsp90 – as a drug target using multiple biophysical and biochemical techniques. Our approach included the characterization of the chemical sensitivity of the parasitic chaperone against a library of known Hsp90 inhibitors by means of differential scanning fluorimetry (DSF). Several compounds identified by this screening procedure were further studied using isothermal titration calorimetry (ITC) and X-ray crystallography, as well as tested in parasite growth inhibitions assays. These experiments led us to the identification of a benzamide derivative compound capable of interacting with TbHsp83 more strongly than with its human homologs and structural rationalization of this selectivity. The results highlight the opportunities created by subtle structural differences to develop new series of compounds to selectively target the Trypanosoma brucei chaperone and effectively kill the sleeping sickness parasite. Sleeping sickness, or human African trypanosomiasis (HAT), is a deadly neglected disease for which new therapeutic options are badly needed. Current drugs have several liabilities including toxicity and route of administration limiting their efficacy to combat the disease. Our study aimed at validating a potential new drug target against Trypanosoma brucei, its heat shock protein 83 (Hsp83). The chaperone was screened against a repurposed library composed of inhibitors against the human Hsp90. The compounds were assayed in their ability to bind the T. brucei protein and to kill the parasite. Our work has identified selective and high-affinity chemical compounds targeting the parasitic Hsp83. Additionally, structural studies were conducted to explore the observed selectivity of selected inhibitors. Our work has validated T. brucei Hsp83 as a potential target for future drug discovery campaigns. It has also shown the strength of repurposing chemical libraries developed against human proteins, emphasizing the possibility to piggyback current and past drug discovery efforts for other diseases in the search for new drugs against neglected tropical diseases.
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Affiliation(s)
- Juan Carlos Pizarro
- The Structural Genomics Consortium (SGC), University of Toronto, Toronto, Ontario, Canada
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana, United States of America
- * E-mail:
| | - Tanya Hills
- The Structural Genomics Consortium (SGC), University of Toronto, Toronto, Ontario, Canada
| | - Guillermo Senisterra
- The Structural Genomics Consortium (SGC), University of Toronto, Toronto, Ontario, Canada
| | - Amy K. Wernimont
- The Structural Genomics Consortium (SGC), University of Toronto, Toronto, Ontario, Canada
| | - Claire Mackenzie
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Neil R. Norcross
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Michael A. J. Ferguson
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Paul G. Wyatt
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Ian H. Gilbert
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Raymond Hui
- The Structural Genomics Consortium (SGC), University of Toronto, Toronto, Ontario, Canada
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Inhibitors of Trypanosoma brucei trypanothione reductase: comparative molecular field analysis modeling and structural basis for selective inhibition. Future Med Chem 2013; 5:1753-62. [DOI: 10.4155/fmc.13.140] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Background: Sleeping sickness is a major cause of death in Africa. Since no secure treatment is available, the development of novel therapeutic agents is urgent. In this context, the enzyme trypanothione reductase (TR) is a prominent molecular target that has been investigated in drug design for sleeping sickness. Results: In this study, comparative molecular field analysis models were generated for a series of Trypanosoma brucei TR inhibitors. Statistically significant results were obtained and the models were applied to predict the activity of external test sets, with good correlation between predicted and experimental results. We have also investigated the structural requirements for the selective inhibition of the parasite‘s enzyme over the human glutathione reductase. Conclusion: The quantitative structure–activity relationship models provided valuable information regarding the essential molecular requirements for the inhibitory activity upon the target protein, providing important insights into the design of more potent and selective TR inhibitors.
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De Oliveira Moreira D, Pereira JA, Taniguti APT, Matsumura CY, Ramos LAF, Areas MA, Neto HS, Marques MJ. Suramin attenuates dystrophin-deficient cardiomyopathy in themdxmouse model of duchenne muscular dystrophy. Muscle Nerve 2013; 48:911-9. [DOI: 10.1002/mus.23858] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2013] [Indexed: 01/16/2023]
Affiliation(s)
- Drielen De Oliveira Moreira
- Departamento de Biologia Estrutural e Funcional; Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP); Campinas SP 13083-970 Brazil
| | - Juliano Alves Pereira
- Departamento de Biologia Estrutural e Funcional; Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP); Campinas SP 13083-970 Brazil
| | - Ana Paula Tiemi Taniguti
- Departamento de Biologia Estrutural e Funcional; Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP); Campinas SP 13083-970 Brazil
| | - Cíntia Yuri Matsumura
- Departamento de Biologia Estrutural e Funcional; Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP); Campinas SP 13083-970 Brazil
| | - Luis Alberto Ferreira Ramos
- Departamento de Biologia Estrutural e Funcional; Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP); Campinas SP 13083-970 Brazil
| | - Miguel Arcanjo Areas
- Departamento de Biologia Estrutural e Funcional; Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP); Campinas SP 13083-970 Brazil
| | - Humberto Santo Neto
- Departamento de Biologia Estrutural e Funcional; Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP); Campinas SP 13083-970 Brazil
| | - Maria Julia Marques
- Departamento de Biologia Estrutural e Funcional; Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP); Campinas SP 13083-970 Brazil
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Pharmacokinetics, Trypanosoma brucei gambiense efficacy, and time of drug action of DB829, a preclinical candidate for treatment of second-stage human African trypanosomiasis. Antimicrob Agents Chemother 2013; 57:5330-43. [PMID: 23959303 DOI: 10.1128/aac.00398-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human African trypanosomiasis (HAT, also called sleeping sickness), a neglected tropical disease endemic to sub-Saharan Africa, is caused by the parasites Trypanosoma brucei gambiense and T. brucei rhodesiense. Current drugs against this disease have significant limitations, including toxicity, increasing resistance, and/or a complicated parenteral treatment regimen. DB829 is a novel aza-diamidine that demonstrated excellent efficacy in mice infected with T. b. rhodesiense or T. b. brucei parasites. The current study examined the pharmacokinetics, in vitro and in vivo activity against T. b. gambiense, and time of drug action of DB829 in comparison to pentamidine. DB829 showed outstanding in vivo efficacy in mice infected with parasites of T. b. gambiense strains, despite having higher in vitro 50% inhibitory concentrations (IC50s) than against T. b. rhodesiense strain STIB900. A single dose of DB829 administered intraperitoneally (5 mg/kg of body weight) cured all mice infected with different T. b. gambiense strains. No cross-resistance was observed between DB829 and pentamidine in T. b. gambiense strains isolated from melarsoprol-refractory patients. Compared to pentamidine, DB829 showed a greater systemic exposure when administered intraperitoneally, partially contributing to its improved efficacy. Isothermal microcalorimetry and in vivo time-to-kill studies revealed that DB829 is a slower-acting trypanocidal compound than pentamidine. A single dose of DB829 (20 mg/kg) administered intraperitoneally clears parasites from mouse blood within 2 to 5 days. In summary, DB829 is a promising preclinical candidate for the treatment of first- and second-stage HAT caused by both Trypanosoma brucei subspecies.
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Kariithi HM, van Oers MM, Vlak JM, Vreysen MJB, Parker AG, Abd-Alla AMM. Virology, Epidemiology and Pathology of Glossina Hytrosavirus, and Its Control Prospects in Laboratory Colonies of the Tsetse Fly, Glossina pallidipes (Diptera; Glossinidae). INSECTS 2013; 4:287-319. [PMID: 26462422 PMCID: PMC4553466 DOI: 10.3390/insects4030287] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/13/2013] [Accepted: 06/13/2013] [Indexed: 01/03/2023]
Abstract
The Glossina hytrosavirus (family Hytrosaviridae) is a double-stranded DNA virus with rod-shaped, enveloped virions. Its 190 kbp genome encodes 160 putative open reading frames. The virus replicates in the nucleus, and acquires a fragile envelope in the cell cytoplasm. Glossina hytrosavirus was first isolated from hypertrophied salivary glands of the tsetse fly, Glossina pallidipes Austen (Diptera; Glossinidae) collected in Kenya in 1986. A certain proportion of laboratory G. pallidipes flies infected by Glossina hytrosavirus develop hypertrophied salivary glands and midgut epithelial cells, gonadal anomalies and distorted sex-ratios associated with reduced insemination rates, fecundity and lifespan. These symptoms are rare in wild tsetse populations. In East Africa, G. pallidipes is one of the most important vectors of African trypanosomosis, a debilitating zoonotic disease that afflicts 37 sub-Saharan African countries. There is a large arsenal of control tactics available to manage tsetse flies and the disease they transmit. The sterile insect technique (SIT) is a robust control tactic that has shown to be effective in eradicating tsetse populations when integrated with other control tactics in an area-wide integrated approach. The SIT requires production of sterile male flies in large production facilities. To supply sufficient numbers of sterile males for the SIT component against G. pallidipes, strategies have to be developed that enable the management of the Glossina hytrosavirus in the colonies. This review provides a historic chronology of the emergence and biogeography of Glossina hytrosavirus, and includes researches on the infectomics (defined here as the functional and structural genomics and proteomics) and pathobiology of the virus. Standard operation procedures for viral management in tsetse mass-rearing facilities are proposed and a future outlook is sketched.
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Affiliation(s)
- Henry M Kariithi
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands.
- Insect Pest Control Laboratories, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Strasse 5, P.O. Box 100, 1400 Vienna, Austria.
- Biotechnology Centre, Kenya Agricultural Research Institute, Waiyaki Way, P.O. Box 14733-00100, Nairobi, Kenya.
| | - Monique M van Oers
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands.
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands.
| | - Marc J B Vreysen
- Insect Pest Control Laboratories, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Strasse 5, P.O. Box 100, 1400 Vienna, Austria.
| | - Andrew G Parker
- Insect Pest Control Laboratories, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Strasse 5, P.O. Box 100, 1400 Vienna, Austria.
| | - Adly M M Abd-Alla
- Insect Pest Control Laboratories, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Strasse 5, P.O. Box 100, 1400 Vienna, Austria.
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Thuita JK, Wolf KK, Murilla GA, Liu Q, Mutuku JN, Chen Y, Bridges AS, Mdachi RE, Ismail MA, Ching S, Boykin DW, Hall JE, Tidwell RR, Paine MF, Brun R, Wang MZ. Safety, pharmacokinetic, and efficacy studies of oral DB868 in a first stage vervet monkey model of human African trypanosomiasis. PLoS Negl Trop Dis 2013; 7:e2230. [PMID: 23755309 PMCID: PMC3674995 DOI: 10.1371/journal.pntd.0002230] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 04/10/2013] [Indexed: 11/19/2022] Open
Abstract
There are no oral drugs for human African trypanosomiasis (HAT, sleeping sickness). A successful oral drug would have the potential to reduce or eliminate the need for patient hospitalization, thus reducing healthcare costs of HAT. The development of oral medications is a key objective of the Consortium for Parasitic Drug Development (CPDD). In this study, we investigated the safety, pharmacokinetics, and efficacy of a new orally administered CPDD diamidine prodrug, 2,5-bis[5-(N-methoxyamidino)-2-pyridyl]furan (DB868; CPD-007-10), in the vervet monkey model of first stage HAT. DB868 was well tolerated at a dose up to 30 mg/kg/day for 10 days, a cumulative dose of 300 mg/kg. Mean plasma levels of biomarkers indicative of liver injury (alanine aminotransferase, aspartate aminotransferase) were not significantly altered by drug administration. In addition, no kidney-mediated alterations in creatinine and urea concentrations were detected. Pharmacokinetic analysis of plasma confirmed that DB868 was orally available and was converted to the active compound DB829 in both uninfected and infected monkeys. Treatment of infected monkeys with DB868 began 7 days post-infection. In the infected monkeys, DB829 attained a median Cmax (dosing regimen) that was 12-fold (3 mg/kg/day for 7 days), 15-fold (10 mg/kg/day for 7 days), and 31-fold (20 mg/kg/day for 5 days) greater than the IC50 (14 nmol/L) against T. b. rhodesiense STIB900. DB868 cured all infected monkeys, even at the lowest dose tested. In conclusion, oral DB868 cured monkeys with first stage HAT at a cumulative dose 14-fold lower than the maximum tolerated dose and should be considered a lead preclinical candidate in efforts to develop a safe, short course (5–7 days), oral regimen for first stage HAT. Development of orally administered medicines for human African trypanosomiasis (HAT) would potentially reduce the need for patient hospitalization, thus lowering healthcare costs. In this study, we investigated the potential of a novel diamidine prodrug, DB868 (CPD-007-10), as an oral treatment for first stage HAT. When administered to uninfected monkeys by oral gavage, DB868 was well tolerated up to a maximum dose of 30 mg/kg/day for 10 days (cumulative dose [CD] = 300 mg/kg). DB868 was absorbed into the systemic circulation and was converted to the active compound DB829 in concentrations that were potentially therapeutic for blood trypanosomes. Subsequently, DB868 was evaluated for efficacy in the first stage vervet monkey model of HAT in which treatment was initiated at 7 days post-infection with T. b. rhodesiense KETRI 2537. All infected monkeys were cured, even at the lowest of the three dose regimens tested: 3 mg/kg/day for 7 days (CD = 21 mg/kg), 10 mg/kg/day for 7 days (CD = 70 mg/kg) and 20 mg/kg/day for 5 days (CD = 100 mg/kg). DB868 conversion to DB829 was comparable between uninfected and infected monkeys. In view of its favourable safety and oral efficacy profile, we conclude that DB868 is a suitable candidate for development as a new treatment for first stage HAT.
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Affiliation(s)
- John K. Thuita
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (KARI-TRC), Kikuyu, Kenya
- University of Basel, Basel, Switzerland
| | - Kristina K. Wolf
- UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Grace A. Murilla
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (KARI-TRC), Kikuyu, Kenya
| | - Qiang Liu
- UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - James N. Mutuku
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (KARI-TRC), Kikuyu, Kenya
| | - Yao Chen
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas, United States of America
| | - Arlene S. Bridges
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Raymond E. Mdachi
- Trypanosomiasis Research Centre, Kenya Agricultural Research Institute (KARI-TRC), Kikuyu, Kenya
| | - Mohamed A. Ismail
- Department of Chemistry, Georgia State University, Atlanta, Georgia, United States of America
| | - Shelley Ching
- SVC Associates, Inc., Apex, North Carolina, United States of America
| | - David W. Boykin
- Department of Chemistry, Georgia State University, Atlanta, Georgia, United States of America
| | - James Edwin Hall
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Richard R. Tidwell
- Department of Pathology and Laboratory Medicine, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Mary F. Paine
- UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Reto Brun
- University of Basel, Basel, Switzerland
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Michael Zhuo Wang
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas, United States of America
- * E-mail:
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Xiao Y, Nguyen S, Kim SH, Volkov OA, Tu BP, Phillips MA. Product feedback regulation implicated in translational control of the Trypanosoma brucei S-adenosylmethionine decarboxylase regulatory subunit prozyme. Mol Microbiol 2013; 88:846-61. [PMID: 23634831 DOI: 10.1111/mmi.12226] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2013] [Indexed: 12/12/2022]
Abstract
Human African sleeping sickness (HAT) is caused by the parasitic protozoan Trypanosoma brucei. Polyamine biosynthesis is an important drug target in the treatment of HAT. Previously we showed that trypanosomatid S-adenosylmethionine decarboxylase (AdoMetDC), a key enzyme for biosynthesis of the polyamine spermidine, is activated by heterodimer formation with an inactive paralogue termed prozyme. Furthermore, prozyme protein levels were regulated in response to reduced AdoMetDC activity. Herein we show that T. brucei encodes three prozyme transcripts. The 3'UTRs of these transcripts were mapped and chloramphenicol acetyltransferase (CAT) reporter constructs were used to identify a 1.2 kb region that contained a 3'UTR prozyme regulatory element sufficient to upregulate CAT protein levels (but not RNA) upon AdoMetDC inhibition, supporting the hypothesis that prozyme expression is regulated translationally. To gain insight into trans-acting factors, genetic rescue of AdoMetDC RNAi knock-down lines with human AdoMetDC was performed leading to rescue of the cell growth block, and restoration of prozyme protein to wild-type levels. Metabolite analysis showed that prozyme protein levels were inversely proportional to intracellular levels of decarboxylated AdoMet (dcAdoMet). These data suggest that prozyme translation may be regulated by dcAdoMet, a metabolite not previously identified to play a regulatory role.
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Affiliation(s)
- Yanjing Xiao
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9041, USA
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Alsford S, Field MC, Horn D. Receptor-mediated endocytosis for drug delivery in African trypanosomes: fulfilling Paul Ehrlich's vision of chemotherapy. Trends Parasitol 2013; 29:207-12. [PMID: 23601931 DOI: 10.1016/j.pt.2013.03.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/05/2013] [Accepted: 03/06/2013] [Indexed: 12/15/2022]
Abstract
Bloodstream-form cells of Trypanosoma brucei exhibit massively increased endocytic activity relative to the insect midgut stage, enabling rapid recycling of variant surface glycoprotein and antibody clearance from the surface. In addition, recent advances have identified a role for receptor-mediated endocytosis in the uptake of the antitrypanosomal drug, suramin, via invariant surface glycoprotein 75, and in the uptake of trypanosome lytic factor 1 via haptoglobin-haemoglobin receptor. Here, we argue that receptor-mediated endocytosis represents both a validated drug target and a promising route for the delivery of novel therapeutics into trypanosomes.
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Affiliation(s)
- Sam Alsford
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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Sanchez LM, Knudsen GM, Hartmann C, De Muylder G, Mascuch SM, Mackey ZB, Gerwick L, Clayton C, McKerrow JH, Linington RG. Examination of the mode of action of the almiramide family of natural products against the kinetoplastid parasite Trypanosoma brucei. JOURNAL OF NATURAL PRODUCTS 2013; 76:630-41. [PMID: 23445522 PMCID: PMC3971013 DOI: 10.1021/np300834q] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Almiramide C is a marine natural product with low micromolar activity against Leishmania donovani, the causative agent of leishmaniasis. We have now shown that almiramide C is also active against the related parasite Trypanosoma brucei, the causative agent of human African trypanosomiasis. A series of activity-based probes have been synthesized to explore both the molecular target of this compound series in T. brucei lysates and site localization through epifluorescence microscopy. These target identification studies indicate that the almiramides likely perturb glycosomal function through disruption of membrane assembly machinery. Glycosomes, which are organelles specific to kinetoplastid parasites, house the first seven steps of glycolysis and have been shown to be essential for parasite survival in the bloodstream stage. There are currently no reported small-molecule disruptors of glycosome function, making the almiramides unique molecular probes for this understudied parasite-specific organelle. Additionally, examination of toxicity in an in vivo zebrafish model has shown that these compounds have little effect on organism development, even at high concentrations, and has uncovered a potential side effect through localization of fluorescent derivatives to zebrafish neuromast cells. Combined, these results further our understanding of the potential value of this lead series as development candidates against T. brucei.
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Affiliation(s)
- Laura M. Sanchez
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
| | - Giselle M. Knudsen
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Claudia Hartmann
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), University of Heidelberg, Heidelberg, Heidelberg, Germany D-69120
| | - Geraldine De Muylder
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Samantha M. Mascuch
- Center for Marine Biotechnology and Biomedicine, Scripps Institute of Oceanography, University of California San Diego, San Diego, CA 92093
| | - Zachary B. Mackey
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Lena Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institute of Oceanography, University of California San Diego, San Diego, CA 92093
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), University of Heidelberg, Heidelberg, Heidelberg, Germany D-69120
| | - James H. McKerrow
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Roger G. Linington
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
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Population pharmacokinetic modeling and deconvolution of enantioselective absorption of eflornithine in the rat. J Pharmacokinet Pharmacodyn 2013; 40:117-28. [PMID: 23307171 DOI: 10.1007/s10928-012-9293-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 12/19/2012] [Indexed: 01/10/2023]
Abstract
Enantioselective pharmacokinetics and absorption of eflornithine in the rat was investigated using population pharmacokinetic modeling and a modified deconvolution method. Bidirectional permeability of L- and D-eflornithine was investigated in Caco-2 cells. The rat was administered racemic eflornithine hydrochloride as a single oral dose [40-3,000 mg/kg bodyweight (BW)] or intravenously (IV) (100-2,700 mg/kg BW infused over 60-400 min). Serial arterial blood samples were collected and L- and D-eflornithine were quantitated with a previously published chiral bioanalysis method. The D:L concentration ratio was determined in rat faeces. Intravenous L-and D-eflornithine plasma concentration-time data was analyzed using population pharmacokinetic modeling and described with a 3-compartment pharmacokinetic model with saturable binding to one of the peripheral compartments. Oral plasma concentration-time data was analyzed using a modified deconvolution method accounting for nonlinearities in the eflornithine pharmacokinetics. Clearance was similar for both enantiomers (3.36 and 3.09 mL/min). Oral bioavailability was estimated by deconvolution at 30 and 59% for L- and D-eflornithine. The D:L concentration ratio in feces was 0.49 and the Caco-2 cell permeability was similar for both enantiomers (6-10 × 10(-8) cm/s) with no evident involvement of active transport or efflux. The results presented here suggest that the difference in the bioavailability between eflornithine enantiomers is caused by a stereoselective difference in extent rather than rate of absorption. The presented modified deconvolution method made it possible to account for the non-linear component in the suggested three-compartment pharmacokinetic model thus rapidly estimating eflornithine oral bioavailability.
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Tiberti N, Matovu E, Hainard A, Enyaru JC, Lejon V, Robin X, Turck N, Ngoyi DM, Krishna S, Bisser S, Courtioux B, Büscher P, Kristensson K, Ndung'u JM, Sanchez JC. New biomarkers for stage determination in Trypanosoma brucei rhodesiense sleeping sickness patients. Clin Transl Med 2013; 2:1. [PMID: 23369533 PMCID: PMC3561069 DOI: 10.1186/2001-1326-2-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 12/25/2012] [Indexed: 12/26/2022] Open
Abstract
Accurate stage determination is crucial in the choice of treatment for patients suffering from sleeping sickness, also known as human African trypanosomiasis (HAT). Current staging methods, based on the counting of white blood cells (WBC) and the detection of parasites in the cerebrospinal fluid (CSF) have limited accuracy. We hypothesized that immune mediators reliable for staging T. b. gambiense HAT could also be used to stratify T. b. rhodesiense patients, the less common form of HAT. A population comprising 85 T. b. rhodesiense patients, 14 stage 1 (S1) and 71 stage 2 (S2) enrolled in Malawi and Uganda, was investigated. The CSF levels of IgM, MMP-9, CXCL13, CXCL10, ICAM-1, VCAM-1, neopterin and B2MG were measured and their staging performances evaluated using receiver operating characteristic (ROC) analyses. IgM, MMP-9 and CXCL13 were the most accurate markers for stage determination (partial AUC 88%, 86% and 85%, respectively). The combination in panels of three molecules comprising CXCL13-CXCL10-MMP-9 or CXCL13-CXCL10-IgM significantly increased their staging ability to partial AUC 94% (p value < 0.01). The present study highlighted new potential markers for stage determination of T. b. rhodesiense patients. Further investigations are needed to better evaluate these molecules, alone or in panels, as alternatives to WBC to make reliable choice of treatment.
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Affiliation(s)
- Natalia Tiberti
- Department of Human Protein Sciences, University of Geneva, Geneva, Switzerland.
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Translation of human African trypanosomiasis biomarkers towards field application. TRANSLATIONAL PROTEOMICS 2013. [DOI: 10.1016/j.trprot.2013.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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