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Appetecchia F, Fabbrizi E, Fiorentino F, Consalvi S, Biava M, Poce G, Rotili D. Transmission-Blocking Strategies for Malaria Eradication: Recent Advances in Small-Molecule Drug Development. Pharmaceuticals (Basel) 2024; 17:962. [PMID: 39065810 PMCID: PMC11279868 DOI: 10.3390/ph17070962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/11/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Malaria drug research and development efforts have resurged in the last decade following the decelerating rate of mortality and malaria cases in endemic regions. The inefficiency of malaria interventions is largely driven by the spreading resistance of the Plasmodium falciparum parasite to current drug regimens and that of the malaria vector, the Anopheles mosquito, to insecticides. In response to the new eradication agenda, drugs that act by breaking the malaria transmission cycle (transmission-blocking drugs), which has been recognized as an important and additional target for intervention, are being developed. These drugs take advantage of the susceptibility of Plasmodium during population bottlenecks before transmission (gametocytes) and in the mosquito vector (gametes, zygotes, ookinetes, oocysts, sporozoites). To date, compounds targeting stage V gametocytes predominate in the chemical library of transmission-blocking drugs, and some of them have entered clinical trials. The targeting of Plasmodium mosquito stages has recently renewed interest in the development of innovative malaria control tools, which hold promise for the application of compounds effective at these stages. In this review, we highlight the major achievements and provide an update on the research of transmission-blocking drugs, with a particular focus on their chemical scaffolds, antiplasmodial activity, and transmission-blocking potential.
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Affiliation(s)
| | | | | | | | | | - Giovanna Poce
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy; (F.A.); (E.F.); (F.F.); (S.C.); (M.B.)
| | - Dante Rotili
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy; (F.A.); (E.F.); (F.F.); (S.C.); (M.B.)
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van Heerden A, Turon G, Duran-Frigola M, Pillay N, Birkholtz LM. Machine Learning Approaches Identify Chemical Features for Stage-Specific Antimalarial Compounds. ACS OMEGA 2023; 8:43813-43826. [PMID: 38027377 PMCID: PMC10666252 DOI: 10.1021/acsomega.3c05664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/18/2023] [Accepted: 10/20/2023] [Indexed: 12/01/2023]
Abstract
Efficacy data from diverse chemical libraries, screened against the various stages of the malaria parasite Plasmodium falciparum, including asexual blood stage (ABS) parasites and transmissible gametocytes, serve as a valuable reservoir of information on the chemical space of compounds that are either active (or not) against the parasite. We postulated that this data can be mined to define chemical features associated with the sole ABS activity and/or those that provide additional life cycle activity profiles like gametocytocidal activity. Additionally, this information could provide chemical features associated with inactive compounds, which could eliminate any future unnecessary screening of similar chemical analogs. Therefore, we aimed to use machine learning to identify the chemical space associated with stage-specific antimalarial activity. We collected data from various chemical libraries that were screened against the asexual (126 374 compounds) and sexual (gametocyte) stages of the parasite (93 941 compounds), calculated the compounds' molecular fingerprints, and trained machine learning models to recognize stage-specific active and inactive compounds. We were able to build several models that predict compound activity against ABS and dual activity against ABS and gametocytes, with Support Vector Machines (SVM) showing superior abilities with high recall (90 and 66%) and low false-positive predictions (15 and 1%). This allowed the identification of chemical features enriched in active and inactive populations, an important outcome that could be mined for essential chemical features to streamline hit-to-lead optimization strategies of antimalarial candidates. The predictive capabilities of the models held true in diverse chemical spaces, indicating that the ML models are therefore robust and can serve as a prioritization tool to drive and guide phenotypic screening and medicinal chemistry programs.
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Affiliation(s)
- Ashleigh van Heerden
- Department
of Biochemistry, Genetics and Microbiology, Institute for Sustainable
Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Gemma Turon
- Ersilia
Open Source Initiative, 28 Belgrave Road, Cambridge CB1 3DE, U.K.
| | | | - Nelishia Pillay
- Department
of Computer Science, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Lyn-Marié Birkholtz
- Department
of Biochemistry, Genetics and Microbiology, Institute for Sustainable
Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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Sharma B, Agarwal A, Awasthi SK. Is structural hybridization invoking new dimensions for antimalarial drug discovery research? RSC Med Chem 2023; 14:1227-1253. [PMID: 37484560 PMCID: PMC10357931 DOI: 10.1039/d3md00083d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 05/01/2023] [Indexed: 07/25/2023] Open
Abstract
Despite effective prevention methods, malaria is a devastating, persistent infection caused by protozoal parasites that result in nearly half a million fatalities annually. Any progress made thus far in the eradication of the disease is jeopardized by the expansion of malaria parasites that have evolved to become resistant to a wide range of drugs, including first-line therapy. To surmount this significant obstacle, it is necessary to develop newly synthesized drugs with multiple modes of action that may have a novel target in various stages of Plasmodium parasite development and this is made possible by the hybridization concept. Hybridization is the combination of at least two diverse pharmacophore units with some linkers bringing about a single molecule with a diverse mode of action. It intensifies a drug's physiological and chemical characteristics, such as absorption, cellular target contact, metabolism, excretion, distribution, and toxicity. This review article outlines the currently published most potent hybrid drugs against the Plasmodium species.
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Affiliation(s)
- Bhawana Sharma
- Chemical Biology Laboratory, Department of Chemistry, University of Delhi Delhi-110007 India
| | - Alka Agarwal
- Department of Medicinal Chemistry, Institute of Medical Sciences, Banaras Hindu University Varanasi-221005 Uttar Pradesh India
| | - Satish Kumar Awasthi
- Chemical Biology Laboratory, Department of Chemistry, University of Delhi Delhi-110007 India
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Yahiya S, Saunders CN, Hassan S, Straschil U, Fischer OJ, Rueda-Zubiaurre A, Haase S, Vizcay-Barrena G, Famodimu MT, Jordan S, Delves MJ, Tate EW, Barnard A, Fuchter MJ, Baum J. A novel class of sulphonamides potently block malaria transmission by targeting a Plasmodium vacuole membrane protein. Dis Model Mech 2023; 16:dmm049950. [PMID: 36715290 PMCID: PMC9934914 DOI: 10.1242/dmm.049950] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 12/13/2022] [Indexed: 01/31/2023] Open
Abstract
Phenotypic cell-based screens are critical tools for discovering candidate drugs for development, yet identification of the cellular target and mode of action of a candidate drug is often lacking. Using an imaging-based screen, we recently discovered an N-[(4-hydroxychroman-4-yl)methyl]-sulphonamide (N-4HCS) compound, DDD01035881, that blocks male gamete formation in the malaria parasite life cycle and subsequent transmission of the parasite to the mosquito with nanomolar activity. To identify the target(s) of DDD01035881, and of the N-4HCS class of compounds more broadly, we synthesised a photoactivatable derivative, probe 2. Photoaffinity labelling of probe 2 coupled with mass spectrometry identified the 16 kDa Plasmodium falciparum parasitophorous vacuole membrane protein Pfs16 as a potential parasite target. Complementary methods including cellular thermal shift assays confirmed that the parent molecule DDD01035881 stabilised Pfs16 in lysates from activated mature gametocytes. Combined with high-resolution, fluorescence and electron microscopy data, which demonstrated that parasites inhibited with N-4HCS compounds phenocopy the targeted deletion of Pfs16 in gametocytes, these data implicate Pfs16 as a likely target of DDD01035881. This finding establishes N-4HCS compounds as being flexible and effective starting candidates from which transmission-blocking antimalarials can be developed in the future.
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Affiliation(s)
- Sabrina Yahiya
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
| | - Charlie N. Saunders
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Sarah Hassan
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Ursula Straschil
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
| | - Oliver J. Fischer
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Ainoa Rueda-Zubiaurre
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Silvia Haase
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
| | - Gema Vizcay-Barrena
- Centre for Ultrastructural Imaging, New Hunt's House, Guy's Campus, King's College London, London SE1 1UL, UK
| | - Mufuliat Toyin Famodimu
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
| | - Sarah Jordan
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
| | - Michael J. Delves
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
| | - Edward W. Tate
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Anna Barnard
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Matthew J. Fuchter
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London W12 OBZ, UK
| | - Jake Baum
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London SW7 2AZ, UK
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Al-Quhaiti MAA, Abdul-Ghani R, Mahdy MAK, Assada MA. Malaria among under-five children in rural communities of Al-Mahweet governorate, Yemen. Malar J 2022; 21:344. [PMID: 36401272 PMCID: PMC9675118 DOI: 10.1186/s12936-022-04371-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022] Open
Abstract
Background Malaria burden among under-five children living in endemic areas of Yemen is largely unknown due to the lack of community-based studies. Therefore, this study determined the prevalence and risk factors associated with falciparum malaria among under-five children in rural communities of Al-Mahweet governorate, Yemen. Methods This community-based, cross-sectional study recruited 400 under-five children from two rural districts of Al-Mahweet governorate in December 2019. Demographic characteristics (gender, age, education and occupation of the child’s parents, and household size) and risk factors associated with malaria were collected through interviews with children’s caregivers using a structured questionnaire. Finger-prick blood was screened for Plasmodium falciparum and non-falciparum species using rapid diagnostic tests (RDTs), and duplicate Giemsa-stained thick and thin blood films were examined for malaria parasites. The density of asexual P. falciparum stages was also estimated. Data were then analysed, and the agreement between the results of thick-film microscopy and RDTs for diagnosing falciparum malaria was assessed using the kappa index. Statistical significance was set at a P-value of < 0.05. Results Plasmodium falciparum was prevalent among 9.8% (95% CI 7.0–13.1) of under-five children in the rural communities of Al-Mahweet, with a median asexual parasite density of 763 ± 2606 parasites/μl of blood (range: 132–4280) and low-to-moderate parasitaemia levels. Approximately one-third of microscopy-confirmed cases were gametocyte carriers. Multivariable logistic regression analysis confirmed that age of three years or older (AOR = 5.6, 95% CI 1.6–19.8; P = 0.007), not sleeping under a mosquito net the previous night of the survey (AOR = 8.0, 95% CI 2.4–27.4; P = 0.001), sleeping outdoors at night (AOR = 4.4, 95% CI 2.0–10.0; P < 0.001), and absence of indoor residual spraying (IRS) during the last year (AOR = 4.2, 95% CI 1.9–9.4; P < 0.001) were the independent predictors of falciparum malaria among under-five children in the rural communities of Al-Mahweet. The observed percentage agreement between thick-film microscopy and RDTs was 98.5%, with a very good agreement (k-index = 0.9) between the two methods for falciparum malaria diagnosis that was statistically significant. Conclusion Approximately one in ten under-five children in rural communities of Al-Mahweet is infected with P. falciparum based on microscopy and RDTs. Age of three years or older, not sleeping under mosquito nets, sleeping outdoors at night and absence of IRS can independently predict falciparum malaria among them. The very good agreement between thick-film microscopy and RDTs for diagnosing falciparum malaria in children supports the usefulness of using RDTs in such resource-limited rural communities.
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Reader J, Opperman DFL, van der Watt ME, Theron A, Leshabane M, da Rocha S, Turner J, Garrabrant K, Piña I, Mills C, Woster PM, Birkholtz L. New Transmission-Selective Antimalarial Agents through Hit-to-Lead Optimization of 2-([1,1'-Biphenyl]-4-carboxamido)benzoic Acid Derivatives. Chembiochem 2022; 23:e202200427. [PMID: 36106425 PMCID: PMC10946866 DOI: 10.1002/cbic.202200427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/14/2022] [Indexed: 11/12/2022]
Abstract
Malaria elimination requires multipronged approaches, including the application of antimalarial drugs able to block human-to-mosquito transmission of malaria parasites. The transmissible gametocytes of Plasmodium falciparum seem to be highly sensitive towards epidrugs, particularly those targeting demethylation of histone post-translational marks. Here, we report exploration of compounds from a chemical library generated during hit-to-lead optimization of inhibitors of the human histone lysine demethylase, KDM4B. Derivatives of 2-([1,1'-biphenyl]-4-carboxamido) benzoic acid, around either the amide or a sulfonamide linker backbone (2-(arylcarboxamido)benzoic acid, 2-carboxamide (arylsulfonamido)benzoic acid and N-(2-(1H-tetrazol-5-yl)phenyl)-arylcarboxamide), showed potent activity towards late-stage gametocytes (stage IV/V) of P. falciparum, with the most potent compound reaching single digit nanomolar activity. Structure-activity relationship trends were evident and frontrunner compounds also displayed microsomal stability and favourable solubility profiles. Simplified synthetic routes support further derivatization of these compounds for further development of these series as malaria transmission-blocking agents.
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Affiliation(s)
- Janette Reader
- Department of BiochemistryGenetics and MicrobiologyInstitute for Sustainable Malaria ControlUniversity of PretoriaLynnwood RoadPretoria0028South Africa
| | - Daniel F. L. Opperman
- Department of BiochemistryGenetics and MicrobiologyInstitute for Sustainable Malaria ControlUniversity of PretoriaLynnwood RoadPretoria0028South Africa
| | - Mariëtte E. van der Watt
- Department of BiochemistryGenetics and MicrobiologyInstitute for Sustainable Malaria ControlUniversity of PretoriaLynnwood RoadPretoria0028South Africa
- School of Health Systems and Public HealthUniversity of Pretoria, HatfieldPretoria0028South Africa
| | - Anjo Theron
- Next Generation HealthCouncil for Scientific and Industrial ResearchPretoria0001South Africa
| | - Meta Leshabane
- Department of BiochemistryGenetics and MicrobiologyInstitute for Sustainable Malaria ControlUniversity of PretoriaLynnwood RoadPretoria0028South Africa
| | - Shanté da Rocha
- Department of BiochemistryGenetics and MicrobiologyInstitute for Sustainable Malaria ControlUniversity of PretoriaLynnwood RoadPretoria0028South Africa
| | - Jonathan Turner
- Department of Drug Discovery and Biomedical SciencesMedical University of South CarolinaCharlestonSC 29425USA
| | - Kathleen Garrabrant
- Department of Drug Discovery and Biomedical SciencesMedical University of South CarolinaCharlestonSC 29425USA
| | - Ivett Piña
- Department of Drug Discovery and Biomedical SciencesMedical University of South CarolinaCharlestonSC 29425USA
| | - Catherine Mills
- Department of Drug Discovery and Biomedical SciencesMedical University of South CarolinaCharlestonSC 29425USA
| | - Patrick M. Woster
- Department of Drug Discovery and Biomedical SciencesMedical University of South CarolinaCharlestonSC 29425USA
| | - Lyn‐Marié Birkholtz
- Department of BiochemistryGenetics and MicrobiologyInstitute for Sustainable Malaria ControlUniversity of PretoriaLynnwood RoadPretoria0028South Africa
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Mianda SM, Invernizzi L, van der Watt ME, Reader J, Moyo P, Birkholtz LM, Maharaj VJ. In vitro dual activity of Aloe marlothii roots and its chemical constituents against Plasmodium falciparum asexual and sexual stage parasites. JOURNAL OF ETHNOPHARMACOLOGY 2022; 297:115551. [PMID: 35850311 DOI: 10.1016/j.jep.2022.115551] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Aloe marlothii A.Berger (Xanthorrhoeaceae) is indigenous to southern African countries where its aqueous preparations are used in traditional medicine to treat several ailments including hypertension, respiratory infections, venereal diseases, chest pain, sore throat and malaria. AIM OF THE STUDY The aims of this study were as follows: (i) isolate and identify the antiplasmodial active compounds in A. marlothii roots. As the water extract was previously inactive, the dichloromethane:methanol (DCM:MeOH) (1:1) was used, (ii) examine the activity of the isolated compounds against Plasmodium falciparum asexual blood stage (ABS) parasites as well as for transmission-blocking activity against gametocytes and gametes, and (iii) to use in silico tools to predict the target(s) of the active molecules. MATERIALS AND METHODS The crude DCM:MeOH (1:1) extract of A. marlothii roots was fractionated on a reverse phase C8 column, using a positive pressure solid-phase extraction (ppSPE) workstation to produce seven fractions. The resulting fractions and the crude DCM:MeOH extract were tested in vitro against P. falciparum (NF54) ABS parasites using the malaria SYBR Green I based-fluorescence assay. Flash silica chromatography and mass-directed preparative high-performance liquid chromatography were utilised to isolate the active compounds. The isolated compounds were evaluated in vitro against P. falciparum asexual (NF54 and K1 strains) and sexual (gametocytes and gametes) stage parasites. Molecular docking was then used for the in silico prediction of targets for the isolated active compounds in P. falciparum. RESULTS The crude extract and two SPE fractions displayed good antiplasmodial activity with >97% and 100% inhibition of ABS parasites proliferation at 10 and 20 μg/mL, respectively. Following UPLC-MS analysis of these active fractions, a targeted purification resulted in the isolation of six compounds identified as aloesaponol I (1), aloesaponarin I (2), aloesaponol IV (3), β-sorigenin-1-O-methylether (4), emodin (5), and chrysophanol (6). Aloesaponarin I (2) was the most bioactive, compared to other isolated constituents, against P. falciparum ABS parasites exhibiting equipotency against the drug-sensitive (NF54) (IC50 = 1.54 μg/mL (5 μM)) and multidrug-resistant (K1) (IC50 = 1.58 μg/mL (5 μM)) strains. Aloesaponol IV (3) showed pronounced activity against late-stage (>90% stage IV/V) gametocytes (IC50 = 6.53 μg/mL (22.6 μM)) demonstrating a 3-fold selective potency towards these sexual stages compared to asexual forms of the parasite (IC50 = 19.77 ± 6.835 μg/mL (68 μM)). Transmission-blocking potential of aloesaponol IV (3) was validated by in vitro inhibition of exflagellation of male gametes (94% inhibition at 20 μg/mL). In silico studies identified β-hematin and DNA topoisomerase II as potential biological targets of compounds 2 and 3, respectively. CONCLUSION The findings from our study substantiate the traditional use of A. marlothii to treat malaria. To our knowledge, this study has provided the first report on the isolation and identification of antiplasmodial compounds from A. marlothii roots. Furthermore, our study has provided the first report on the transmission-blocking potential of one of the compounds from the genus Aloe, motivating for the investigation of other species within this genus for their potential P. falciparum transmission-blocking activity.
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Affiliation(s)
- Sephora Mutombo Mianda
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028, South Africa.
| | - Luke Invernizzi
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028, South Africa.
| | - Mariëtte E van der Watt
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria, 0028, South Africa; Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Gezina, Pretoria, 0031, South Africa.
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria, 0028, South Africa.
| | - Phanankosi Moyo
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028, South Africa; Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria, 0028, South Africa.
| | - Lyn-Marié Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria, 0028, South Africa.
| | - Vinesh J Maharaj
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, 0028, South Africa.
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Muema JM, Bargul JL, Obonyo MA, Njeru SN, Matoke-Muhia D, Mutunga JM. Contemporary exploitation of natural products for arthropod-borne pathogen transmission-blocking interventions. Parasit Vectors 2022; 15:298. [PMID: 36002857 PMCID: PMC9404607 DOI: 10.1186/s13071-022-05367-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/16/2022] [Indexed: 11/26/2022] Open
Abstract
An integrated approach to innovatively counter the transmission of various arthropod-borne diseases to humans would benefit from strategies that sustainably limit onward passage of infective life cycle stages of pathogens and parasites to the insect vectors and vice versa. Aiming to accelerate the impetus towards a disease-free world amid the challenges posed by climate change, discovery, mindful exploitation and integration of active natural products in design of pathogen transmission-blocking interventions is of high priority. Herein, we provide a review of natural compounds endowed with blockade potential against transmissible forms of human pathogens reported in the last 2 decades from 2000 to 2021. Finally, we propose various translational strategies that can exploit these pathogen transmission-blocking natural products into design of novel and sustainable disease control interventions. In summary, tapping these compounds will potentially aid in integrated combat mission to reduce disease transmission trends.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000, Nairobi, 00200, Kenya.
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000, Nairobi, 00200, Kenya.,International Centre of Insect Physiology and Ecology (Icipe), P.O. Box 30772, Nairobi, 00100, Kenya
| | - Meshack A Obonyo
- Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, Egerton, 20115, Kenya
| | - Sospeter N Njeru
- Centre for Traditional Medicine and Drug Research (CTMDR), Kenya Medical Research Institute (KEMRI), P.O. Box 54840, Nairobi, 00200, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research Development (CBRD), Kenya Medical Research Institute (KEMRI), P.O. Box 54840, Nairobi, 00200, Kenya
| | - James M Mutunga
- Department of Biological Sciences, Mount Kenya University (MKU), P.O. Box 54, Thika, 01000, Kenya.,School of Engineering Design, Technology and Professional Programs, Pennsylvania State University, University Park, PA, 16802, USA
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Reader J, van der Watt ME, Birkholtz LM. Streamlined and Robust Stage-Specific Profiling of Gametocytocidal Compounds Against Plasmodium falciparum. Front Cell Infect Microbiol 2022; 12:926460. [PMID: 35846744 PMCID: PMC9282888 DOI: 10.3389/fcimb.2022.926460] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/30/2022] [Indexed: 12/29/2022] Open
Abstract
Malaria elimination is dependent on the ability to target both the pathogenic and transmissible stages of the human malaria parasite, Plasmodium falciparum. These forms of the parasite are differentiated by unique developmental stages, each with their own biological mechanisms and processes. These individual stages therefore also respond differently to inhibitory compounds, and this complicates the discovery of multistage active antimalarial agents. The search for compounds with transmission-blocking activity has focused on screening for activity on mature gametocytes, with only limited descriptions available for the activity of such compounds on immature stage gametocytes. This therefore poses a gap in the profiling of antimalarial agents for pan-reactive, multistage activity to antimalarial leads. Here, we optimized an effective and robust strategy for the simple and cost-effective description of the stage-specific action of gametocytocidal antimalarial compounds.
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Affiliation(s)
- Janette Reader
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Mariette E. van der Watt
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa
| | - Lyn-Marié Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- *Correspondence: Lyn-Marié Birkholtz,
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10
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van der Watt ME, Reader J, Birkholtz LM. Adapt or Die: Targeting Unique Transmission-Stage Biology for Malaria Elimination. Front Cell Infect Microbiol 2022; 12:901971. [PMID: 35755845 PMCID: PMC9218253 DOI: 10.3389/fcimb.2022.901971] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/06/2022] [Indexed: 12/25/2022] Open
Abstract
Plasmodium parasites have a complex life cycle that includes development in the human host as well as the Anopheles vector. Successful transmission of the parasite between its host and vector therefore requires the parasite to balance its investments in asexual replication and sexual reproduction, varying the frequency of sexual commitment to persist within the human host and generate future opportunities for transmission. The transmission window is extended further by the ability of stage V gametocytes to circulate in peripheral blood for weeks, whereas immature stage I to IV gametocytes sequester in the bone marrow and spleen until final maturation. Due to the low gametocyte numbers in blood circulation and with the ease of targeting such life cycle bottlenecks, transmission represents an efficient target for therapeutic intervention. The biological process of Plasmodium transmission is a multistage, multifaceted process and the past decade has seen a much deeper understanding of the molecular mechanisms and regulators involved. Clearly, specific and divergent processes are used during transmission compared to asexual proliferation, which both poses challenges but also opportunities for discovery of transmission-blocking antimalarials. This review therefore presents an update of our molecular understanding of gametocyte and gamete biology as well as the status of transmission-blocking activities of current antimalarials and lead development compounds. By defining the biological components associated with transmission, considerations for the development of new transmission-blocking drugs to target such untapped but unique biology is suggested as an important, main driver for transmission-blocking drug discovery.
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Affiliation(s)
- Mariëtte E van der Watt
- Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa
| | - Janette Reader
- Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Lyn-Marié Birkholtz
- Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
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11
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Gametocyte-specific and all-blood-stage transmission-blocking chemotypes discovered from high throughput screening on Plasmodium falciparum gametocytes. Commun Biol 2022; 5:547. [PMID: 35668202 PMCID: PMC9170688 DOI: 10.1038/s42003-022-03510-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 05/19/2022] [Indexed: 11/25/2022] Open
Abstract
Blocking Plasmodium falciparum human-to-mosquito transmission is essential for malaria elimination, nonetheless drugs killing the pathogenic asexual stages are generally inactive on the parasite transmissible stages, the gametocytes. Due to technical and biological limitations in high throughput screening of non-proliferative stages, the search for gametocyte-killing molecules so far tested one tenth the number of compounds screened on asexual stages. Here we overcome these limitations and rapidly screened around 120,000 compounds, using not purified, bioluminescent mature gametocytes. Orthogonal gametocyte assays, selectivity assays on human cells and asexual parasites, followed by compound clustering, brought to the identification of 84 hits, half of which are gametocyte selective and half with comparable activity against sexual and asexual parasites. We validated seven chemotypes, three of which are, to the best of our knowledge, novel. These molecules are able to inhibit male gametocyte exflagellation and block parasite transmission through the Anopheles mosquito vector in a standard membrane feeding assay. This work shows that interrogating a wide and diverse chemical space, with a streamlined gametocyte HTS and hit validation funnel, holds promise for the identification of dual stage and gametocyte-selective compounds to be developed into new generation of transmission blocking drugs for malaria elimination. High-throughput screening of 120,000 compounds followed by counter-screening and validation assays reveals candidate antimalarial drugs that kill Plasmodium falciparum sexual and asexual blood stages blocking parasite transmission through mosquito.
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12
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Barbieri D, Gomez L, Royer L, Dupuy F, Franetich JF, Tefit M, N’Dri ME, Mazier D, Silvie O, Moreno-Sabater A, Lavazec C. The Phosphodiesterase Inhibitor Tadalafil Promotes Splenic Retention of Plasmodium falciparum Gametocytes in Humanized Mice. Front Cell Infect Microbiol 2022; 12:883759. [PMID: 35694548 PMCID: PMC9174641 DOI: 10.3389/fcimb.2022.883759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 04/26/2022] [Indexed: 11/13/2022] Open
Abstract
The persistence of erythrocytes infected with Plasmodium falciparum gametocytes in the bloodstream is closely related to the modulation of their mechanical properties. New drugs that increase the stiffness of infected erythrocytes may thus represent a novel approach to block malaria parasite transmission. The phosphodiesterase inhibitor tadalafil has been shown to impair the ability of infected erythrocytes to circulate in an in vitro model for splenic retention. Here, we used a humanized mouse model to address in vivo the effect of tadalafil on the circulation kinetics of mature gametocyte-infected erythrocytes. We show that stiff immature gametocyte-infected erythrocytes are retained in the spleen of humanized mice at rates comparable to that of the in vitro model. Accordingly, tadalafil-induced stiffening of mature gametocyte-infected erythrocytes impairs their circulation in the bloodstream and triggers their retention by the spleen. These in vivo results validate that tadalafil is a novel drug lead potentially capable of blocking malaria parasite transmission by targeting GIE mechanical properties.
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Affiliation(s)
- Daniela Barbieri
- INSERM U1016, CNRS UMR8104, Université Paris Cité, Institut Cochin, Paris, France
| | - Lina Gomez
- INSERM U1016, CNRS UMR8104, Université Paris Cité, Institut Cochin, Paris, France
| | - Ludivine Royer
- INSERM U1016, CNRS UMR8104, Université Paris Cité, Institut Cochin, Paris, France
| | - Florian Dupuy
- INSERM U1016, CNRS UMR8104, Université Paris Cité, Institut Cochin, Paris, France
| | - Jean-François Franetich
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Maurel Tefit
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Marie-Esther N’Dri
- INSERM U1016, CNRS UMR8104, Université Paris Cité, Institut Cochin, Paris, France
| | - Dominique Mazier
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Olivier Silvie
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Alicia Moreno-Sabater
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
- Service de Parasitologie-Mycologie Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpital Saint-Antoine, Paris, France
| | - Catherine Lavazec
- INSERM U1016, CNRS UMR8104, Université Paris Cité, Institut Cochin, Paris, France
- *Correspondence: Catherine Lavazec,
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13
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Connacher J, von Grüning H, Birkholtz L. Histone Modification Landscapes as a Roadmap for Malaria Parasite Development. Front Cell Dev Biol 2022; 10:848797. [PMID: 35433676 PMCID: PMC9010790 DOI: 10.3389/fcell.2022.848797] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/04/2022] [Indexed: 12/26/2022] Open
Abstract
Plasmodium falciparum remains the deadliest parasite species in the world, responsible for 229 million cases of human malaria in 2019. The ability of the P. falciparum parasite to progress through multiple life cycle stages and thrive in diverse host and vector species hinges on sophisticated mechanisms of epigenetic regulation of gene expression. Emerging evidence indicates such epigenetic control exists in concentric layers, revolving around core histone post-translational modification (PTM) landscapes. Here, we provide a necessary update of recent epigenome research in malaria parasites, focusing specifically on the ability of dynamic histone PTM landscapes to orchestrate the divergent development and differentiation pathways in P. falciparum parasites. In addition to individual histone PTMs, we discuss recent findings that imply functional importance for combinatorial PTMs in P. falciparum parasites, representing an operational histone code. Finally, this review highlights the remaining gaps and provides strategies to address these to obtain a more thorough understanding of the histone modification landscapes that are at the center of epigenetic regulation in human malaria parasites.
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14
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Consalvi S, Tammaro C, Appetecchia F, Biava M, Poce G. Malaria transmission blocking compounds: a patent review. Expert Opin Ther Pat 2022; 32:649-666. [PMID: 35240899 DOI: 10.1080/13543776.2022.2049239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Despite substantial progress in the field, malaria remains a global health issue and currently available control strategies are not sufficient to achieve eradication. Agents able to prevent transmission are likely to have a strong impact on malaria control and have been prioritized as a primary objective to reduce the number of secondary infections. Therefore, there is an increased interest in finding novel drugs targeting sexual stages of Plasmodium and innovative methods to target malaria transmission from host to vector, and vice versa. AREAS COVERED This review covers innovative transmission-blocking inventions patented between 2015 and October 2021. The focus is on chemical interventions which could be used as "chemical vaccines" to prevent transmission (small molecules, carbohydrates, and polypeptides). EXPERT OPINION Even though the development of novel strategies to block transmission still requires fundamental additional research and a deeper understanding of parasite sexual stages biology, the research in this field has significantly accelerated. Among innovative inventions patented over the last six years, the surface-delivery of antimalarial drugs to kill transmission-stages parasites in mosquitoes holds the highest promise for success in malaria control strategies, opening completely new scenarios in malaria transmission-blocking drug discovery.
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Affiliation(s)
- Sara Consalvi
- Department of Chemistry and Technologies of Drug, Sapienza University of Rome, piazzale A. Moro 5, 00185 Rome, Italy
| | - Chiara Tammaro
- Department of Chemistry and Technologies of Drug, Sapienza University of Rome, piazzale A. Moro 5, 00185 Rome, Italy
| | - Federico Appetecchia
- Department of Chemistry and Technologies of Drug, Sapienza University of Rome, piazzale A. Moro 5, 00185 Rome, Italy
| | - Mariangela Biava
- Department of Chemistry and Technologies of Drug, Sapienza University of Rome, piazzale A. Moro 5, 00185 Rome, Italy
| | - Giovanna Poce
- Department of Chemistry and Technologies of Drug, Sapienza University of Rome, piazzale A. Moro 5, 00185 Rome, Italy
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15
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Birkholtz LM, Alano P, Leroy D. Transmission-blocking drugs for malaria elimination. Trends Parasitol 2022; 38:390-403. [DOI: 10.1016/j.pt.2022.01.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/19/2022] [Accepted: 01/24/2022] [Indexed: 12/24/2022]
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16
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Niemand J, van Biljon R, van der Watt M, van Heerden A, Reader J, van Wyk R, Orchard L, Chibale K, Llinás M, Birkholtz LM. Chemogenomic Fingerprints Associated with Stage-Specific Gametocytocidal Compound Action against Human Malaria Parasites. ACS Infect Dis 2021; 7:2904-2916. [PMID: 34569223 DOI: 10.1021/acsinfecdis.1c00373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Kinase-focused inhibitors previously revealed compounds with differential activity against different stages of Plasmodium falciparum gametocytes. MMV666810, a 2-aminopyrazine, is more active on late-stage gametocytes, while a pyrazolopyridine, MMV674850, preferentially targets early-stage gametocytes. Here, we probe the biological mechanisms underpinning this differential stage-specific killing using in-depth transcriptome fingerprinting. Compound-specific chemogenomic profiles were observed with MMV674850 treatment associated with biological processes shared between asexual blood stage parasites and early-stage gametocytes but not late-stage gametocytes. MMV666810 has a distinct profile with clustered gene sets associated primarily with late-stage gametocyte development, including Ca2+-dependent protein kinases (CDPK1 and 5) and serine/threonine protein kinases (FIKK). Chemogenomic profiling therefore highlights essential processes in late-stage gametocytes, on a transcriptional level. This information is important to prioritize compounds that preferentially compromise late-stage gametocytes for further development as transmission-blocking antimalarials.
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Affiliation(s)
- Jandeli Niemand
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Riëtte van Biljon
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Ashleigh van Heerden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Roelof van Wyk
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
| | - Lindsey Orchard
- Department of Biochemistry & Molecular Biology and the Huck Centre for Malaria Research, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kelly Chibale
- Drug Discovery and Development Centre (H3D), University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
- South African Medical Research Council, Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
| | - Manuel Llinás
- Department of Biochemistry & Molecular Biology and the Huck Centre for Malaria Research, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Lyn-Marié Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, Pretoria 0028, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria 0028, South Africa
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17
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Cruz-Bustos T, Feix AS, Ruttkowski B, Joachim A. Sexual Development in Non-Human Parasitic Apicomplexa: Just Biology or Targets for Control? Animals (Basel) 2021; 11:ani11102891. [PMID: 34679913 PMCID: PMC8532714 DOI: 10.3390/ani11102891] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/30/2021] [Accepted: 10/01/2021] [Indexed: 12/17/2022] Open
Abstract
Simple Summary Cellular reproduction is a key part of the apicomplexan life cycle, and both mitotic (asexual) and meiotic (sexual) cell divisions produce new individual cells. Sexual reproduction in most eukaryotic taxa indicates that it has had considerable success during evolution, and it must confer profound benefits, considering its significant costs. The phylum Apicomplexa consists of almost exclusively parasitic single-celled eukaryotic organisms that can affect a wide host range of animals from invertebrates to mammals. Their development is characterized by complex steps in which asexual and sexual replication alternate and the fertilization of a macrogamete by a microgamete results in the formation of a zygote that undergoes meiosis, thus forming a new generation of asexual stages. In apicomplexans, sex is assumed to be induced by the (stressful) condition of having to leave the host, and either gametes or zygotes (or stages arising from it) are transmitted to a new host. Therefore, sex and meiosis are linked to parasite transmission, and consequently dissemination, which are key to the parasitic lifestyle. We hypothesize that improved knowledge of the sexual biology of the Apicomplexa will be essential to design and implement effective transmission-blocking strategies for the control of the major parasites of this group. Abstract The phylum Apicomplexa is a major group of protozoan parasites including gregarines, coccidia, haemogregarines, haemosporidia and piroplasms, with more than 6000 named species. Three of these subgroups, the coccidia, hemosporidia, and piroplasms, contain parasites that cause important diseases of humans and animals worldwide. All of them have complex life cycles involving a switch between asexual and sexual reproduction, which is key to their development. Fertilization (i.e., fusion of female and male cells) results in the formation of a zygote that undergoes meiosis, forming a new generation of asexual stages. In eukaryotes, sexual reproduction is the predominant mode of recombination and segregation of DNA. Sex is well documented in many protist groups, and together with meiosis, is frequently linked with transmission to new hosts. Apicomplexan sexual stages constitute a bottleneck in the life cycle of these parasites, as they are obligatory for the development of new transmissible stages. Consequently, the sexual stages represent attractive targets for vaccination. Detailed understanding of apicomplexan sexual biology will pave the way for the design and implementation of effective transmission-blocking strategies for parasite control. This article reviews the current knowledge on the sexual development of Apicomplexa and the progress in transmission-blocking vaccines for their control, their advantages and limitations and outstanding questions for the future.
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18
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Leshabane M, Dziwornu GA, Coertzen D, Reader J, Moyo P, van der Watt M, Chisanga K, Nsanzubuhoro C, Ferger R, Erlank E, Venter N, Koekemoer L, Chibale K, Birkholtz LM. Benzimidazole Derivatives Are Potent against Multiple Life Cycle Stages of Plasmodium falciparum Malaria Parasites. ACS Infect Dis 2021; 7:1945-1955. [PMID: 33673735 DOI: 10.1021/acsinfecdis.0c00910] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The continued emergence of resistance to front-line antimalarial treatments is of great concern. Therefore, new compounds that potentially have a novel target in various developmental stages of Plasmodium parasites are needed to treat patients and halt the spread of malaria. Here, several benzimidazole derivatives were screened for activity against the symptom-causing intraerythrocytic asexual blood stages and the transmissible gametocyte stages of P. falciparum. Submicromolar activity was obtained for 54 compounds against asexual blood stage parasites with 6 potent at IC50 < 100 nM while not displaying any marked toxicity against mammalian cells. Nanomolar potency was also observed against gametocytes with two compounds active against early stage gametocytes and two compounds active against late-stage gametocytes. The transmission-blocking potential of the latter was confirmed as they could prevent male gamete exflagellation and the lead compound reduced transmission by 72% in an in vivo mosquito feeding model. These compounds therefore have activity against multiple stages of Plasmodium parasites with potential for differential targets.
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Affiliation(s)
- Meta Leshabane
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | | | - Dina Coertzen
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Janette Reader
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Phanankosi Moyo
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Mariëtte van der Watt
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Kelly Chisanga
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | | | - Richard Ferger
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Erica Erlank
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, and Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, 2193, South Africa
| | - Nelius Venter
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, and Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, 2193, South Africa
| | - Lizette Koekemoer
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, and Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, 2193, South Africa
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
- South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
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19
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van Heerden A, van Wyk R, Birkholtz LM. Machine Learning Uses Chemo-Transcriptomic Profiles to Stratify Antimalarial Compounds With Similar Mode of Action. Front Cell Infect Microbiol 2021; 11:688256. [PMID: 34268139 PMCID: PMC8277430 DOI: 10.3389/fcimb.2021.688256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/04/2021] [Indexed: 11/26/2022] Open
Abstract
The rapid development of antimalarial resistance motivates the continued search for novel compounds with a mode of action (MoA) different to current antimalarials. Phenotypic screening has delivered thousands of promising hit compounds without prior knowledge of the compounds’ exact target or MoA. Whilst the latter is not initially required to progress a compound in a medicinal chemistry program, identifying the MoA early can accelerate hit prioritization, hit-to-lead optimization and preclinical combination studies in malaria research. The effects of drug treatment on a cell can be observed on systems level in changes in the transcriptome, proteome and metabolome. Machine learning (ML) algorithms are powerful tools able to deconvolute such complex chemically-induced transcriptional signatures to identify pathways on which a compound act and in this manner provide an indication of the MoA of a compound. In this study, we assessed different ML approaches for their ability to stratify antimalarial compounds based on varied chemically-induced transcriptional responses. We developed a rational gene selection approach that could identify predictive features for MoA to train and generate ML models. The best performing model could stratify compounds with similar MoA with a classification accuracy of 76.6 ± 6.4%. Moreover, only a limited set of 50 biomarkers was required to stratify compounds with similar MoA and define chemo-transcriptomic fingerprints for each compound. These fingerprints were unique for each compound and compounds with similar targets/MoA clustered together. The ML model was specific and sensitive enough to group new compounds into MoAs associated with their predicted target and was robust enough to be extended to also generate chemo-transcriptomic fingerprints for additional life cycle stages like immature gametocytes. This work therefore contributes a new strategy to rapidly, specifically and sensitively indicate the MoA of compounds based on chemo-transcriptomic fingerprints and holds promise to accelerate antimalarial drug discovery programs.
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Affiliation(s)
- Ashleigh van Heerden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, South Africa.,University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
| | - Roelof van Wyk
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, South Africa.,University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield, South Africa.,University of Pretoria Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, South Africa
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20
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Bouyer G, Barbieri D, Dupuy F, Marteau A, Sissoko A, N'Dri ME, Neveu G, Bedault L, Khodabux N, Roman D, Houzé S, Siciliano G, Alano P, Martins RM, Lopez-Rubio JJ, Clain J, Duval R, Egée S, Lavazec C. Plasmodium falciparum sexual parasites regulate infected erythrocyte permeability. Commun Biol 2020; 3:726. [PMID: 33262483 PMCID: PMC7708629 DOI: 10.1038/s42003-020-01454-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 10/30/2020] [Indexed: 11/28/2022] Open
Abstract
To ensure the transport of nutrients necessary for their survival, Plasmodium falciparum parasites increase erythrocyte permeability to diverse solutes. These new permeation pathways (NPPs) have been extensively characterized in the pathogenic asexual parasite stages, however the existence of NPPs has never been investigated in gametocytes, the sexual stages responsible for transmission to mosquitoes. Here, we show that NPPs are still active in erythrocytes infected with immature gametocytes and that this activity declines along gametocyte maturation. Our results indicate that NPPs are regulated by cyclic AMP (cAMP) signaling cascade, and that the decrease in cAMP levels in mature stages results in a slowdown of NPP activity. We also show that NPPs facilitate the uptake of artemisinin derivatives and that phosphodiesterase (PDE) inhibitors can reactivate NPPs and increase drug uptake in mature gametocytes. These processes are predicted to play a key role in P. falciparum gametocyte biology and susceptibility to antimalarials. Bouyer et al. report that the new permeation pathways (NPP), responsible of modulating erythrocyte permeability to diverse solutes and considered only to be in pathogenic asexual stages of P. falciparum, are also active in erythrocytes infected with immature gametocytes and this activity declines with gametocyte maturation. NPPs are regulated by the cAMP signalling cascade, and the decrease in cAMP levels in mature stages slows NPP activity.
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Affiliation(s)
- Guillaume Bouyer
- Sorbonne Université, CNRS UMR 8227, Station Biologique de Roscoff, Roscoff, France.,Laboratoire d'excellence GR-Ex, Paris, France
| | - Daniela Barbieri
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, Inserm U1016, CNRS UMR 8104, Institut Cochin, Paris, France
| | - Florian Dupuy
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, Inserm U1016, CNRS UMR 8104, Institut Cochin, Paris, France
| | - Anthony Marteau
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, Inserm U1016, CNRS UMR 8104, Institut Cochin, Paris, France
| | - Abdoulaye Sissoko
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, IRD 261, MERIT, Paris, France
| | - Marie-Esther N'Dri
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, Inserm U1016, CNRS UMR 8104, Institut Cochin, Paris, France
| | - Gaelle Neveu
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, Inserm U1016, CNRS UMR 8104, Institut Cochin, Paris, France
| | - Laurianne Bedault
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, Inserm U1016, CNRS UMR 8104, Institut Cochin, Paris, France
| | - Nabiha Khodabux
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, Inserm U1016, CNRS UMR 8104, Institut Cochin, Paris, France
| | - Diana Roman
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, IRD 261, MERIT, Paris, France
| | - Sandrine Houzé
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, IRD 261, MERIT, Paris, France
| | | | | | - Rafael M Martins
- Université de Montpellier 1 & 2, CNRS 5290, IRD 224, MIVEGEC, Montpellier, France
| | | | - Jérome Clain
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, IRD 261, MERIT, Paris, France
| | - Romain Duval
- Laboratoire d'excellence GR-Ex, Paris, France.,Université de Paris, IRD 261, MERIT, Paris, France
| | - Stéphane Egée
- Sorbonne Université, CNRS UMR 8227, Station Biologique de Roscoff, Roscoff, France.,Laboratoire d'excellence GR-Ex, Paris, France
| | - Catherine Lavazec
- Laboratoire d'excellence GR-Ex, Paris, France. .,Université de Paris, Inserm U1016, CNRS UMR 8104, Institut Cochin, Paris, France.
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21
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Moyo P, Mugumbate G, Eloff JN, Louw AI, Maharaj VJ, Birkholtz LM. Natural Products: A Potential Source of Malaria Transmission Blocking Drugs? Pharmaceuticals (Basel) 2020; 13:E251. [PMID: 32957668 PMCID: PMC7558993 DOI: 10.3390/ph13090251] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 12/17/2022] Open
Abstract
The ability to block human-to-mosquito and mosquito-to-human transmission of Plasmodium parasites is fundamental to accomplish the ambitious goal of malaria elimination. The WHO currently recommends only primaquine as a transmission-blocking drug but its use is severely restricted by toxicity in some populations. New, safe and clinically effective transmission-blocking drugs therefore need to be discovered. While natural products have been extensively investigated for the development of chemotherapeutic antimalarial agents, their potential use as transmission-blocking drugs is comparatively poorly explored. Here, we provide a comprehensive summary of the activities of natural products (and their derivatives) of plant and microbial origins against sexual stages of Plasmodium parasites and the Anopheles mosquito vector. We identify the prevailing challenges and opportunities and suggest how these can be mitigated and/or exploited in an endeavor to expedite transmission-blocking drug discovery efforts from natural products.
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Affiliation(s)
- Phanankosi Moyo
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag x20, Hatfield, 0028 Pretoria, South Africa;
| | - Grace Mugumbate
- Department of Chemistry, School of Natural Sciences and Mathematics, Chinhoyi University of Technology, Private Bag, 7724 Chinhoyi, Zimbabwe;
| | - Jacobus N. Eloff
- Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag x04, Onderstepoort 0110 Pretoria, South Africa;
| | - Abraham I. Louw
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag x20, Hatfield, 0028 Pretoria, South Africa;
| | - Vinesh J. Maharaj
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag x20, Hatfield, 0028 Pretoria, South Africa;
| | - Lyn-Marié Birkholtz
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag x20, Hatfield, 0028 Pretoria, South Africa;
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22
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Tajuddeen N, Van Heerden FR. Antiplasmodial natural products: an update. Malar J 2019; 18:404. [PMID: 31805944 PMCID: PMC6896759 DOI: 10.1186/s12936-019-3026-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 11/21/2019] [Indexed: 11/25/2022] Open
Abstract
Background Malaria remains a significant public health challenge in regions of the world where it is endemic. An unprecedented decline in malaria incidences was recorded during the last decade due to the availability of effective control interventions, such as the deployment of artemisinin-based combination therapy and insecticide-treated nets. However, according to the World Health Organization, malaria is staging a comeback, in part due to the development of drug resistance. Therefore, there is an urgent need to discover new anti-malarial drugs. This article reviews the literature on natural products with antiplasmodial activity that was reported between 2010 and 2017. Methods Relevant literature was sourced by searching the major scientific databases, including Web of Science, ScienceDirect, Scopus, SciFinder, Pubmed, and Google Scholar, using appropriate keyword combinations. Results and Discussion A total of 1524 compounds from 397 relevant references, assayed against at least one strain of Plasmodium, were reported in the period under review. Out of these, 39% were described as new natural products, and 29% of the compounds had IC50 ≤ 3.0 µM against at least one strain of Plasmodium. Several of these compounds have the potential to be developed into viable anti-malarial drugs. Also, some of these compounds could play a role in malaria eradication by targeting gametocytes. However, the research into natural products with potential for blocking the transmission of malaria is still in its infancy stage and needs to be vigorously pursued.
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Affiliation(s)
- Nasir Tajuddeen
- School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa
| | - Fanie R Van Heerden
- School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X01, Scottsville, Pietermaritzburg, 3209, South Africa.
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23
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van der Watt ME, Reader J, Churchyard A, Nondaba SH, Lauterbach SB, Niemand J, Abayomi S, van Biljon RA, Connacher JI, van Wyk RDJ, Le Manach C, Paquet T, González Cabrera D, Brunschwig C, Theron A, Lozano-Arias S, Rodrigues JFI, Herreros E, Leroy D, Duffy J, Street LJ, Chibale K, Mancama D, Coetzer TL, Birkholtz LM. Potent Plasmodium falciparum gametocytocidal compounds identified by exploring the kinase inhibitor chemical space for dual active antimalarials. J Antimicrob Chemother 2019; 73:1279-1290. [PMID: 29420756 DOI: 10.1093/jac/dky008] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 01/02/2018] [Indexed: 01/06/2023] Open
Abstract
Objectives Novel chemical tools to eliminate malaria should ideally target both the asexual parasites and transmissible gametocytes. Several imidazopyridazines (IMPs) and 2-aminopyridines (2-APs) have been described as potent antimalarial candidates targeting lipid kinases. However, these have not been extensively explored for stage-specific inhibition of gametocytes in Plasmodium falciparum parasites. Here we provide an in-depth evaluation of the gametocytocidal activity of compounds from these chemotypes and identify novel starting points for dual-acting antimalarials. Methods We evaluated compounds against P. falciparum gametocytes using several assay platforms for cross-validation and stringently identified hits that were further profiled for stage specificity, speed of action and ex vivo efficacy. Physicochemical feature extraction and chemogenomic fingerprinting were applied to explore the kinase inhibition susceptibility profile. Results We identified 34 compounds with submicromolar activity against late stage gametocytes, validated across several assay platforms. Of these, 12 were potent at <100 nM (8 were IMPs and 4 were 2-APs) and were also active against early stage gametocytes and asexual parasites, with >1000-fold selectivity towards the parasite over mammalian cells. Front-runner compounds targeted mature gametocytes within 48 h and blocked transmission to mosquitoes. The resultant chemogenomic fingerprint of parasites treated with the lead compounds revealed the importance of targeting kinases in asexual parasites and gametocytes. Conclusions This study encompasses an in-depth evaluation of the kinase inhibitor space for gametocytocidal activity. Potent lead compounds have enticing dual activities and highlight the importance of targeting the kinase superfamily in malaria elimination strategies.
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Affiliation(s)
- Mariëtte E van der Watt
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Janette Reader
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Alisje Churchyard
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Sindisiwe H Nondaba
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Sonja B Lauterbach
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Jandeli Niemand
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Sijuade Abayomi
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Riëtte A van Biljon
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Jessica I Connacher
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Roelof D J van Wyk
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Claire Le Manach
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Tanya Paquet
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Diego González Cabrera
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Christel Brunschwig
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Anjo Theron
- Biosciences, Council for Scientific and Industrial Research, PO Box 395, Pretoria 0001, South Africa
| | - Sonia Lozano-Arias
- GlaxoSmithKline, Tres Cantos Medicines Development Campus, Severo Ochoa, 2, 28760 Tres Cantos, Madrid, Spain
| | - Janneth F I Rodrigues
- GlaxoSmithKline, Tres Cantos Medicines Development Campus, Severo Ochoa, 2, 28760 Tres Cantos, Madrid, Spain
| | - Esperanza Herreros
- GlaxoSmithKline, Tres Cantos Medicines Development Campus, Severo Ochoa, 2, 28760 Tres Cantos, Madrid, Spain
| | - Didier Leroy
- Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215, Geneva, Switzerland
| | - James Duffy
- Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215, Geneva, Switzerland
| | - Leslie J Street
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kelly Chibale
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,South African Medical Research Council, Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
| | - Dalu Mancama
- Biosciences, Council for Scientific and Industrial Research, PO Box 395, Pretoria 0001, South Africa
| | - Theresa L Coetzer
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
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24
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Dodean RA, Kancharla P, Li Y, Melendez V, Read L, Bane CE, Vesely B, Kreishman-Deitrick M, Black C, Li Q, Sciotti RJ, Olmeda R, Luong TL, Gaona H, Potter B, Sousa J, Marcsisin S, Caridha D, Xie L, Vuong C, Zeng Q, Zhang J, Zhang P, Lin H, Butler K, Roncal N, Gaynor-Ohnstad L, Leed SE, Nolan C, Huezo SJ, Rasmussen SA, Stephens MT, Tan JC, Cooper RA, Smilkstein MJ, Pou S, Winter RW, Riscoe MK, Kelly JX. Discovery and Structural Optimization of Acridones as Broad-Spectrum Antimalarials. J Med Chem 2019; 62:3475-3502. [PMID: 30852885 DOI: 10.1021/acs.jmedchem.8b01961] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Malaria remains one of the deadliest diseases in the world today. Novel chemoprophylactic and chemotherapeutic antimalarials are needed to support the renewed eradication agenda. We have discovered a novel antimalarial acridone chemotype with dual-stage activity against both liver-stage and blood-stage malaria. Several lead compounds generated from structural optimization of a large library of novel acridones exhibit efficacy in the following systems: (1) picomolar inhibition of in vitro Plasmodium falciparum blood-stage growth against multidrug-resistant parasites; (2) curative efficacy after oral administration in an erythrocytic Plasmodium yoelii murine malaria model; (3) prevention of in vitro Plasmodium berghei sporozoite-induced development in human hepatocytes; and (4) protection of in vivo P. berghei sporozoite-induced infection in mice. This study offers the first account of liver-stage antimalarial activity in an acridone chemotype. Details of the design, chemistry, structure-activity relationships, safety, metabolic/pharmacokinetic studies, and mechanistic investigation are presented herein.
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Affiliation(s)
- Rozalia A Dodean
- Department of Chemistry , Portland State University , Portland , Oregon 97201 , United States.,Department of Veterans Affairs Medical Center , Portland , Oregon 97239 , United States
| | - Papireddy Kancharla
- Department of Chemistry , Portland State University , Portland , Oregon 97201 , United States
| | - Yuexin Li
- Department of Chemistry , Portland State University , Portland , Oregon 97201 , United States.,Department of Veterans Affairs Medical Center , Portland , Oregon 97239 , United States
| | - Victor Melendez
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Lisa Read
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Charles E Bane
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Brian Vesely
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Mara Kreishman-Deitrick
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Chad Black
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Qigui Li
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Richard J Sciotti
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Raul Olmeda
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Thu-Lan Luong
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Heather Gaona
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Brittney Potter
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Jason Sousa
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Sean Marcsisin
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Diana Caridha
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Lisa Xie
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Chau Vuong
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Qiang Zeng
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Jing Zhang
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Ping Zhang
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Hsiuling Lin
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Kirk Butler
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Norma Roncal
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Lacy Gaynor-Ohnstad
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Susan E Leed
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Christina Nolan
- Division of Experimental Therapeutics , Walter Reed Army Institute of Research , Silver Spring , Maryland 20910 , United States
| | - Stephanie J Huezo
- Department of Natural Sciences and Mathematics , Dominican University of California , San Rafael , California 94901 , United States
| | - Stephanie A Rasmussen
- Department of Natural Sciences and Mathematics , Dominican University of California , San Rafael , California 94901 , United States
| | | | | | - Roland A Cooper
- Department of Natural Sciences and Mathematics , Dominican University of California , San Rafael , California 94901 , United States
| | - Martin J Smilkstein
- Department of Veterans Affairs Medical Center , Portland , Oregon 97239 , United States
| | - Sovitj Pou
- Department of Veterans Affairs Medical Center , Portland , Oregon 97239 , United States
| | - Rolf W Winter
- Department of Chemistry , Portland State University , Portland , Oregon 97201 , United States.,Department of Veterans Affairs Medical Center , Portland , Oregon 97239 , United States
| | - Michael K Riscoe
- Department of Chemistry , Portland State University , Portland , Oregon 97201 , United States.,Department of Veterans Affairs Medical Center , Portland , Oregon 97239 , United States
| | - Jane X Kelly
- Department of Chemistry , Portland State University , Portland , Oregon 97201 , United States.,Department of Veterans Affairs Medical Center , Portland , Oregon 97239 , United States
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25
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Henry NB, Sermé SS, Siciliano G, Sombié S, Diarra A, Sagnon N, Traoré AS, Sirima SB, Soulama I, Alano P. Biology of Plasmodium falciparum gametocyte sex ratio and implications in malaria parasite transmission. Malar J 2019; 18:70. [PMID: 30866941 PMCID: PMC6417185 DOI: 10.1186/s12936-019-2707-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/05/2019] [Indexed: 11/10/2022] Open
Abstract
While significant advances have been made in understanding Plasmodium falciparum gametocyte biology and its relationship with malaria parasite transmission, the gametocyte sex ratio contribution to this process still remains a relevant research question. The present review discusses the biology of sex determination in P. falciparum, the underlying host and parasite factors, the sex specific susceptibility to drugs, the effect of sex ratio dynamics on malaria parasite transmission and the development of gametocyte sex specific diagnosis tools. Despite the inherent differences across several studies and approaches, the emerging picture highlights a potentially relevant contribution of the P. falciparum gametocyte sex ratio in the modulation of malaria parasite transmission. The increasing availability of molecular methods to measure gametocyte sex ratio will enable evaluation of important parameters, such as the impact of drug treatment on gametocyte sex ratio in vitro and in vivo as well as the changes of gametocyte sex ratios in natural infections, key steps towards elucidating how these parameters affect parasite infectiousness to the mosquito vectors.
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Affiliation(s)
- Noëlie Béré Henry
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Samuel Sindié Sermé
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Giulia Siciliano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Salif Sombié
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Amidou Diarra
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - N'fale Sagnon
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | | | - Sodiomon Bienvenu Sirima
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso.,Groupe de Recherche Action Santé, Ouagadougou, Burkina Faso
| | - Issiaka Soulama
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso.
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy.
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26
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Screening the Pathogen Box for Molecules Active against Plasmodium Sexual Stages Using a New Nanoluciferase-Based Transgenic Line of P. berghei Identifies Transmission-Blocking Compounds. Antimicrob Agents Chemother 2018; 62:AAC.01053-18. [PMID: 30181368 DOI: 10.1128/aac.01053-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 08/28/2018] [Indexed: 12/12/2022] Open
Abstract
Malaria remains an important parasitic disease with a large morbidity and mortality burden. Plasmodium transmission-blocking (TB) compounds are essential for achieving malaria elimination efforts. Recent efforts to develop high-throughput screening (HTS) methods to identify compounds that inhibit or kill gametocytes, the Plasmodium sexual stage infectious to mosquitoes, have yielded insight into new TB compounds. However, the activities of these compounds against gametes, formed in the first minutes of mosquito infection, are typically not assessed, unless screened in a standard membrane feeding assay, a labor-intensive assay. We demonstrate here the generation of a Plasmodium model for drug screens against gametes and fertilization. The new P. berghei line, named Ookluc, was genetically and pharmacologically validated and scalable for HTS. Screening the Pathogen Box from the Medicines for Malaria Venture using the new model identified promising TB compounds. The use of Ookluc in different libraries of compounds may aid in the identification of transmission-blocking drugs not assessed in screens against asexual stages or gametocytes.
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27
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Macedo TS, Villarreal W, Couto CC, Moreira DRM, Navarro M, Machado M, Prudêncio M, Batista AA, Soares MBP. Platinum(ii)-chloroquine complexes are antimalarial agents against blood and liver stages by impairing mitochondrial function. Metallomics 2018; 9:1548-1561. [PMID: 28960224 DOI: 10.1039/c7mt00196g] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chloroquine is an antimalarial agent with strong activity against the blood stage of Plasmodium infection, but with low activity against the parasite's liver stage. In addition, the resistance to chloroquine limits its clinical use. The discovery of new molecules possessing multistage activity and overcoming drug resistance is needed. One possible strategy to achieve this lies in combining antimalarial quinolones with the pharmacological effects of transition metals. We investigated the antimalarial activity of four platinum(ii) complexes composed of chloroquine and phosphine ligands, denoted as WV-90, WV-92, WV-93 and WV-94. In comparison with chloroquine, the complexes were less potent against the chloroquine-sensitive 3D7 strain but they were as active as chloroquine in inhibiting the chloroquine-resistant W2 strain of P. falciparum. Regarding selectivity, the complexes WV-90 and WV-93 displayed higher indexes. Unlike chloroquine, the complexes act as irreversible parasiticidal agents against trophozoites and the WV-93 complex displayed activity against the hepatic stage of P. berghei. The in vivo suppression activity against P. berghei in the Peters 4 day test displayed by the complexes was similar to that of chloroquine. However, the efficacy in an established P. berghei infection in the Thompson test was superior for the WV-93 complex compared to chloroquine. The complexes' antimalarial mechanism of action is initiated by inhibiting the hemozoin formation. While chloroquine efficiently inhibits hemozoin, parasites treated with the platinum complexes display residual hemozoin crystals. This is explained since the interaction of the platinum complexes with ferriprotoporphyrin is weaker than that of chloroquine. However, the complexes caused a loss of mitochondrial integrity and subsequent reduction in mitochondrial activity, and their effects on mitochondria were more pronounced than those in the chloroquine-treated parasites. The dual effect of the platinum complexes may explain their activity against the hemozoin-lacking parasites (hepatic stage), where chloroquine has no activity. Our findings indicate that the platinum(ii)-chloroquine complexes are multifunctional antimalarial compounds and reinforce the importance of metal complexes in antimalarial drug discovery.
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Affiliation(s)
- Taís S Macedo
- FIOCRUZ, Instituto Gonçalo Moniz, CEP 40296-710, Salvador, BA, Brazil.
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28
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Colmenarejo G, Lozano S, González-Cortés C, Calvo D, Sanchez-Garcia J, Matilla JLP, Leroy D, Rodrigues J. Predicting transmission blocking potential of anti-malarial compounds in the Mosquito Feeding Assay using Plasmodium falciparum Male Gamete Inhibition Assay. Sci Rep 2018; 8:7764. [PMID: 29773818 PMCID: PMC5958111 DOI: 10.1038/s41598-018-26125-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/04/2018] [Indexed: 02/01/2023] Open
Abstract
Plasmodium falciparum Standard Membrane Feeding Assay (PfSMFA) is the current gold standard mosquito based confirmatory transmission blocking (TrB) assay for human malaria. However, owing to its complexity only selected gametocytocidal molecules are progressed into SMFA. Predictive tools for evaluation of TrB behavior of compounds in SMFA would be extremely beneficial, but lack of substantially large data sets from many mosquito feeds preempts the ability to perform correlations between outcomes from in vitro assays and SMFA. Here, a total of 44 different anti-malarial compounds were screened for inhibitory effect on male gamete formation in exflagellation inhibition assay (EIA) and the same drug-treated parasites were fed to mosquitoes in SMFA. Regression analysis was performed between outcomes of the two assays and regression models were applied to a randomly selected validation set of four compounds indicating no overfitting and good predictive power. In addition, the pIC50 for 11 different compounds obtained in the EIA was also correlated with pIC50’s in SMFA. Resulting regression models provided pIC50 predictions in SMFA with reasonably good accuracy thereby demonstrating the use of a simple in vitro assay to predict TrB of molecules in a complex mosquito based assay.
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Affiliation(s)
- Gonzalo Colmenarejo
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain.,Biostatistics and Bioinformatics Unit, IMDEA Food Institute, CEI UAM+CSIC, Ctra Cantoblanco 8, 28049, Madrid, Spain
| | - Sonia Lozano
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Carolina González-Cortés
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain.,Complejo Asistencial Universitario de León. Altos de Nava s/n, 24071, León, Spain
| | - David Calvo
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Juliana Sanchez-Garcia
- In vivo Science & Delivery (IVSD), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Jesús-Luís Presa Matilla
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Didier Leroy
- Medicines for Malaria Venture, Route de Pré-Bois 20, 1215, Geneva 15, Switzerland
| | - Janneth Rodrigues
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain.
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29
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Miura K, Crompton PD. What goes around comes around: modeling malaria transmission from humans back to mosquitos. J Clin Invest 2018. [PMID: 29528336 DOI: 10.1172/jci120260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Malaria, caused by mosquito-transmitted Plasmodium parasites, continues to take a major toll on global health. The development of drugs and vaccines that reduce malaria transmission from humans back to mosquitos could contribute to the control and eventual eradication of malaria, but research models for the early clinical evaluation of candidate interventions are lacking. In this issue of the JCI, Collins and colleagues report the successful transmission of Plasmodium falciparum parasites from humans to mosquitoes during controlled human malaria infection, thus providing a potential tool to accelerate the development of much needed transmission-blocking drugs and vaccines.
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Affiliation(s)
- Kazutoyo Miura
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, and
| | - Peter D Crompton
- Malaria Infection Biology and Immunity Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, Maryland, USA
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Bioluminescence Method for In Vitro Screening of Plasmodium Transmission-Blocking Compounds. Antimicrob Agents Chemother 2017; 61:AAC.02699-16. [PMID: 28348156 PMCID: PMC5444155 DOI: 10.1128/aac.02699-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/23/2017] [Indexed: 12/12/2022] Open
Abstract
The sporogonic stage of the life cycle of Plasmodium spp., the causative agents of malaria, occurs inside the parasite's mosquito vector, where a process of fertilization, meiosis, and mitotic divisions culminates in the generation of large numbers of mammalian-infective sporozoites. Efforts to cultivate Plasmodium mosquito stages in vitro have proved challenging and yielded only moderate success. Here, we describe a methodology that simplifies the in vitro screening of much-needed transmission-blocking (TB) compounds employing a bioluminescence-based method to monitor the in vitro development of sporogonic stages of the rodent malaria parasite Plasmodium berghei. Our proof-of-principle assessment of the in vitro TB activity of several commonly used antimalarial compounds identified cycloheximide, thiostrepton, and atovaquone as the most active compounds against the parasite's sporogonic stages. The TB activity of these compounds was further confirmed by in vivo studies that validated our newly developed in vitro approach to TB compound screening.
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Siciliano G, Santha Kumar TR, Bona R, Camarda G, Calabretta MM, Cevenini L, Davioud-Charvet E, Becker K, Cara A, Fidock DA, Alano P. A high susceptibility to redox imbalance of the transmissible stages of Plasmodium falciparum revealed with a luciferase-based mature gametocyte assay. Mol Microbiol 2017; 104:306-318. [PMID: 28118506 DOI: 10.1111/mmi.13626] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2017] [Indexed: 12/18/2022]
Abstract
The goal to prevent Plasmodium falciparum transmission from humans to mosquitoes requires the identification of targetable metabolic processes in the mature (stage V) gametocytes, the sexual stages circulating in the bloodstream. This task is complicated by the apparently low metabolism of these cells, which renders them refractory to most antimalarial inhibitors and constrains the development of specific and sensitive cell-based assays. Here, we identify and functionally characterize the regulatory regions of the P. falciparum gene PF3D7_1234700, encoding a CPW-WPC protein and named here Upregulated in Late Gametocytes (ULG8), which we have leveraged to express reporter genes in mature male and female gametocytes. Using transgenic parasites containing a pfULG8-luciferase cassette, we investigated the susceptibility of stage V gametocytes to compounds specifically affecting redox metabolism. Our results reveal a high sensitivity of mature gametocytes to the glutathione reductase inhibitor and redox cycler drug methylene blue (MB). Using isobologram analysis, we find that a concomitant inhibition of the parasite enzyme glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase, a key component of NADPH synthesis, potently synergizes MB activity. These data suggest that redox metabolism and detoxification activity play an unsuspected yet vital role in stage V gametocytes, rendering these cells exquisitely sensitive to decreases in NADPH concentration.
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Affiliation(s)
- Giulia Siciliano
- Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Rome, Italy
| | - T R Santha Kumar
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA
| | - Roberta Bona
- Dipartimento Farmaco, Istituto Superiore di Sanità, Rome, Italy
| | - Grazia Camarda
- Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Rome, Italy
| | | | - Luca Cevenini
- Department of Chemistry "G. Ciamician", University of Bologna, Bologna, Italy
| | - Elisabeth Davioud-Charvet
- European School of Chemistry, Polymers and Materials (ECPM), UMR 7509 Centre National de la Recherche Scientifique and University of Strasbourg, Strasbourg, France
| | - Katja Becker
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Germany
| | - Andrea Cara
- Dipartimento Farmaco, Istituto Superiore di Sanità, Rome, Italy
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA.,Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, NY, USA
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, Rome, Italy
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Metabolomic Profiling of the Malaria Box Reveals Antimalarial Target Pathways. Antimicrob Agents Chemother 2016; 60:6635-6649. [PMID: 27572391 DOI: 10.1128/aac.01224-16] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/16/2016] [Indexed: 12/11/2022] Open
Abstract
The threat of widespread drug resistance to frontline antimalarials has renewed the urgency for identifying inexpensive chemotherapeutic compounds that are effective against Plasmodium falciparum, the parasite species responsible for the greatest number of malaria-related deaths worldwide. To aid in the fight against malaria, a recent extensive screening campaign has generated thousands of lead compounds with low micromolar activity against blood stage parasites. A subset of these leads has been compiled by the Medicines for Malaria Venture (MMV) into a collection of structurally diverse compounds known as the MMV Malaria Box. Currently, little is known regarding the activity of these Malaria Box compounds on parasite metabolism during intraerythrocytic development, and a majority of the targets for these drugs have yet to be defined. Here we interrogated the in vitro metabolic effects of 189 drugs (including 169 of the drug-like compounds from the Malaria Box) using ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). The resulting metabolic fingerprints provide information on the parasite biochemical pathways affected by pharmacologic intervention and offer a critical blueprint for selecting and advancing lead compounds as next-generation antimalarial drugs. Our results reveal several major classes of metabolic disruption, which allow us to predict the mode of action (MoA) for many of the Malaria Box compounds. We anticipate that future combination therapies will be greatly informed by these results, allowing for the selection of appropriate drug combinations that simultaneously target multiple metabolic pathways, with the aim of eliminating malaria and forestalling the expansion of drug-resistant parasites in the field.
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