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Smith CF, Modahl CM, Ceja Galindo D, Larson KY, Maroney SP, Bahrabadi L, Brandehoff NP, Perry BW, McCabe MC, Petras D, Lomonte B, Calvete JJ, Castoe TA, Mackessy SP, Hansen KC, Saviola AJ. Assessing Target Specificity of the Small Molecule Inhibitor MARIMASTAT to Snake Venom Toxins: A Novel Application of Thermal Proteome Profiling. Mol Cell Proteomics 2024; 23:100779. [PMID: 38679388 PMCID: PMC11154231 DOI: 10.1016/j.mcpro.2024.100779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 04/09/2024] [Accepted: 04/25/2024] [Indexed: 05/01/2024] Open
Abstract
New treatments that circumvent the pitfalls of traditional antivenom therapies are critical to address the problem of snakebite globally. Numerous snake venom toxin inhibitors have shown promising cross-species neutralization of medically significant venom toxins in vivo and in vitro. The development of high-throughput approaches for the screening of such inhibitors could accelerate their identification, testing, and implementation and thus holds exciting potential for improving the treatments and outcomes of snakebite envenomation worldwide. Energetics-based proteomic approaches, including thermal proteome profiling and proteome integral solubility alteration (PISA) assays, represent "deep proteomics" methods for high throughput, proteome-wide identification of drug targets and ligands. In the following study, we apply thermal proteome profiling and PISA methods to characterize the interactions between venom toxin proteoforms in Crotalus atrox (Western Diamondback Rattlesnake) and the snake venom metalloprotease (SVMP) inhibitor marimastat. We investigate its venom proteome-wide effects and characterize its interactions with specific SVMP proteoforms, as well as its potential targeting of non-SVMP venom toxin families. We also compare the performance of PISA thermal window and soluble supernatant with insoluble precipitate using two inhibitor concentrations, providing the first demonstration of the utility of a sensitive high-throughput PISA-based approach to assess the direct targets of small molecule inhibitors for snake venom.
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Affiliation(s)
- Cara F Smith
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, Colorado, USA
| | - Cassandra M Modahl
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, UK
| | - David Ceja Galindo
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, Colorado, USA
| | - Keira Y Larson
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, Colorado, USA
| | - Sean P Maroney
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, Colorado, USA
| | - Lilyrose Bahrabadi
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, Colorado, USA
| | - Nicklaus P Brandehoff
- Rocky Mountain Poison and Drug Center, Denver Health and Hospital Authority, Denver, Colorado, USA
| | - Blair W Perry
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - Maxwell C McCabe
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, Colorado, USA
| | - Daniel Petras
- CMFI Cluster of Excellence, University of Tuebingen, Tuebingen, Germany; Department of Biochemistry, University of California Riverside, Riverside, California, USA
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Juan J Calvete
- Evolutionary and Translational Venomics Laboratory, Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Todd A Castoe
- Department of Biology, The University of Texas Arlington, Texas, USA
| | - Stephen P Mackessy
- Department of Biological Sciences, University of Northern Colorado, Greeley, Colorado, USA
| | - Kirk C Hansen
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, Colorado, USA
| | - Anthony J Saviola
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, Colorado, USA.
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2
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Hus KK, Buczkowicz J, Pietrowska M, Petrilla V, Petrillová M, Legáth J, Litschka-Koen T, Bocian A. Venom diversity in Naja mossambica: Insights from proteomic and immunochemical analyses reveal intraspecific differences. PLoS Negl Trop Dis 2024; 18:e0012057. [PMID: 38557658 PMCID: PMC11008852 DOI: 10.1371/journal.pntd.0012057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 04/11/2024] [Accepted: 03/07/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Intraspecific variations in snake venom composition have been extensively documented, contributing to the diverse clinical effects observed in envenomed patients. Understanding these variations is essential for developing effective snakebite management strategies and targeted antivenom therapies. We aimed to comprehensively investigate venoms from three distinct populations of N. mossambica from Eswatini, Limpopo, and KwaZulu-Natal regions in Africa in terms of their protein composition and reactivity with three commercial antivenoms (SAIMR polyvalent, EchiTAb+ICP, and Antivipmyn Africa). METHODOLOGY/PRINCIPAL FINDINGS Naja mossambica venoms from Eswatini region exhibited the highest content of neurotoxic proteins, constituting 20.70% of all venom proteins, compared to Limpopo (13.91%) and KwaZulu-Natal (12.80%), and was characterized by the highest diversity of neurotoxic proteins, including neurotoxic 3FTxs, Kunitz-type inhibitors, vespryns, and mamba intestinal toxin 1. KwaZulu-Natal population exhibited considerably lower cytotoxic 3FTx, higher PLA2 content, and significant diversity in low-abundant proteins. Conversely, Limpopo venoms demonstrated the least diversity as demonstrated by electrophoretic and mass spectrometry analyses. Immunochemical assessments unveiled differences in venom-antivenom reactivity, particularly concerning low-abundance proteins. EchiTAb+ICP antivenom demonstrated superior reactivity in serial dilution ELISA assays compared to SAIMR polyvalent. CONCLUSIONS/SIGNIFICANCE Our findings reveal a substantial presence of neurotoxic proteins in N. mossambica venoms, challenging previous understandings of their composition. Additionally, the detection of numerous peptides aligning to uncharacterized proteins or proteins with unknown functions underscores a critical issue with existing venom protein databases, emphasizing the substantial gaps in our knowledge of snake venom protein components. This underscores the need for enhanced research in this domain. Moreover, our in vitro immunological assays suggest EchiTAb+ICP's potential as an alternative to SAIMR antivenom, requiring confirmation through prospective in vivo neutralization studies.
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Affiliation(s)
- Konrad K. Hus
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland
| | - Justyna Buczkowicz
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland
| | - Monika Pietrowska
- Maria Sklodowska-Curie National Research Institute of Oncology, Gliwice, Poland
| | - Vladimír Petrilla
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Košice, Slovakia
- Zoological Department, Zoological Garden Košice, Košice-Kavečany, Slovakia
| | - Monika Petrillová
- Department of General Competencies, University of Veterinary Medicine and Pharmacy, Košice, Slovakia
| | - Jaroslav Legáth
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland
- Department of Pharmacology and Toxicology, University of Veterinary Medicine and Pharmacy, Košice, Slovakia
| | | | - Aleksandra Bocian
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland
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3
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Marriott AE, Casewell NR, Lilley E, Gutiérrez JM, Ainsworth S. Improving in vivo assays in snake venom and antivenom research: A community discussion. F1000Res 2024; 13:192. [PMID: 38708289 PMCID: PMC11066530 DOI: 10.12688/f1000research.148223.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/06/2024] [Indexed: 05/07/2024] Open
Abstract
On the 26 th January 2023, a free to attend, 'improving in vivo snake venom research: a community discussion' meeting was held virtually. This webinar brought together researchers from around the world to discuss current neutralisation of venom lethality mouse assays that are used globally to assess the efficacy of therapies for snakebite envenoming. The assay's strengths and weaknesses were highlighted, and we discussed what improvements could be made to refine and reduce animal testing, whilst supporting preclinical antivenom and drug discovery for snakebite envenoming. This report summarises the issues highlighted, the discussions held, with additional commentary on key perspectives provided by the authors.
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Affiliation(s)
- Amy E Marriott
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, England, L3 5RF, UK
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Nicholas R Casewell
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Elliot Lilley
- National Centre for the Replacement, Reduction and Refinement of Animals in Research, London, NW1 2BE, UK
| | - José-María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, 11501-2060, Costa Rica
| | - Stuart Ainsworth
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, England, L3 5RF, UK
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
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4
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Slagboom J, Lewis AH, Schouten WM, van Haperen R, Veltman M, Bittenbinder MA, Vonk FJ, Casewell NR, Grosveld F, Drabek D, Kool J. High throughput identification of human monoclonal antibodies and heavy-chain-only antibodies to treat snakebite. Toxicon X 2024; 21:100185. [PMID: 38425752 PMCID: PMC10901844 DOI: 10.1016/j.toxcx.2024.100185] [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: 08/19/2023] [Revised: 12/12/2023] [Accepted: 01/31/2024] [Indexed: 03/02/2024] Open
Abstract
Snakebite envenoming is a priority Neglected Tropical Disease that causes an estimated 81,000-135,000 fatalities each year. The development of a new generation of safer, affordable, and accessible antivenom therapies is urgently needed. With this goal in mind, rigorous characterisation of the specific toxins in snake venom is key to generating novel therapies for snakebite. Monoclonal antibodies directed against venom toxins are emerging as potentially strong candidates in the development of new snakebite diagnostics and treatment. Venoms comprise many different toxins of which several are responsible for their pathological effects. Due to the large variability of venoms within and between species, formulations of combinations of human antibodies are proposed as the next generation antivenoms. Here a high-throughput screening method employing antibody-based ligand fishing of venom toxins in 384 filter-well plate format has been developed to determine the antibody target/s The approach uses Protein G beads for antibody capture followed by exposure to a full venom or purified toxins to bind their respective ligand toxin(s). This is followed by a washing/centrifugation step to remove non-binding toxins and an in-well tryptic digest. Finally, peptides from each well are analysed by nanoLC-MS/MS and subsequent Mascot database searching to identify the bound toxin/s for each antibody under investigation. The approach was successfully validated to rapidly screen antibodies sourced from hybridomas, derived from venom-immunised mice expressing either regular human antibodies or heavy-chain-only human antibodies (HCAbs).
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Affiliation(s)
- Julien Slagboom
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081HV, the Netherlands
| | - Abigail H. Lewis
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081HV, the Netherlands
| | - Wietse M. Schouten
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081HV, the Netherlands
| | - Rien van Haperen
- Department of Cell Biology and Genetics, Faculty of Medicine, Erasmus Medical Center Rotterdam, 3000 DR, Rotterdam, the Netherlands
- Harbour BioMed, Erasmus Medical Center Rotterdam, 3000 DR, Rotterdam, the Netherlands
| | - Mieke Veltman
- Department of Cell Biology and Genetics, Faculty of Medicine, Erasmus Medical Center Rotterdam, 3000 DR, Rotterdam, the Netherlands
- Harbour BioMed, Erasmus Medical Center Rotterdam, 3000 DR, Rotterdam, the Netherlands
| | - Mátyás A. Bittenbinder
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081HV, the Netherlands
- Naturalis Biodiversity Center, 2333 CR, Leiden, the Netherlands
| | - Freek J. Vonk
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081HV, the Netherlands
- Naturalis Biodiversity Center, 2333 CR, Leiden, the Netherlands
| | - Nicholas R. Casewell
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Frank Grosveld
- Department of Cell Biology and Genetics, Faculty of Medicine, Erasmus Medical Center Rotterdam, 3000 DR, Rotterdam, the Netherlands
- Harbour BioMed, Erasmus Medical Center Rotterdam, 3000 DR, Rotterdam, the Netherlands
| | - Dubravka Drabek
- Department of Cell Biology and Genetics, Faculty of Medicine, Erasmus Medical Center Rotterdam, 3000 DR, Rotterdam, the Netherlands
- Harbour BioMed, Erasmus Medical Center Rotterdam, 3000 DR, Rotterdam, the Netherlands
| | - Jeroen Kool
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081HV, the Netherlands
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Cardoso FF, Salvador GHM, Cavalcante WLG, Dal-Pai M, Fontes MRDM. BthTX-I, a phospholipase A 2-like toxin, is inhibited by the plant cinnamic acid derivative: chlorogenic acid. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2024; 1872:140988. [PMID: 38142025 DOI: 10.1016/j.bbapap.2023.140988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 12/11/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023]
Abstract
Snakebite is a significant health concern in tropical and subtropical regions, particularly in Africa, Asia, and Latin America, resulting in more than 2.7 million envenomations and an estimated one hundred thousand fatalities annually. The Bothrops genus is responsible for the majority of snakebite envenomings in Latin America and Caribbean countries. Accidents involving snakes from this genus are characterized by local symptoms that often lead to permanent sequelae and death. However, specific antivenoms exhibit limited effectiveness in inhibiting local tissue damage. Phospholipase A2-like (PLA2-like) toxins emerge as significant contributors to local myotoxicity in accidents involving Bothrops species. As a result, they represent a crucial target for prospective treatments. Some natural and synthetic compounds have shown the ability to reduce or abolish the myotoxic effects of PLA2-like proteins. In this study, we employed a combination approach involving myographic, morphological, biophysical and bioinformatic techniques to investigate the interaction between chlorogenic acid (CGA) and BthTX-I, a PLA2-like toxin. CGA provided a protection of 71.8% on muscle damage in a pre-incubation treatment. Microscale thermophoresis and circular dichroism experiments revealed that CGA interacted with the BthTX-I while preserving its secondary structure. CGA exhibited an affinity to the toxin that ranks among the highest observed for a natural compound. Bioinformatics simulations indicated that CGA inhibitor binds to the toxin's hydrophobic channel in a manner similar to other phenolic compounds previously investigated. These findings suggest that CGA interferes with the allosteric transition of the non-activated toxin, and the stability of the dimeric assembly of its activated state.
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Affiliation(s)
- Fábio Florença Cardoso
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | | | - Walter Luís Garrido Cavalcante
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Maeli Dal-Pai
- Departamento de Biologia Estrutural e Funcional, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Marcos Roberto de Mattos Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; Instituto de Estudos Avançados do Mar (IEAMar), Universidade Estadual Paulista (UNESP), São Vicente, SP, Brazil.
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6
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Clare RH, Dawson CA, Westhorpe A, Albulescu LO, Woodley CM, Mosallam N, Chong DJW, Kool J, Berry NG, O’Neill PM, Casewell NR. Snakebite drug discovery: high-throughput screening to identify novel snake venom metalloproteinase toxin inhibitors. Front Pharmacol 2024; 14:1328950. [PMID: 38273820 PMCID: PMC10808794 DOI: 10.3389/fphar.2023.1328950] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 12/21/2023] [Indexed: 01/27/2024] Open
Abstract
Snakebite envenoming results in ∼100,000 deaths per year, with close to four times as many victims left with life-long sequelae. Current antivenom therapies have several limitations including high cost, variable cross-snake species efficacy and a requirement for intravenous administration in a clinical setting. Next-generation snakebite therapies are being widely investigated with the aim to improve cost, efficacy, and safety. In recent years several small molecule drugs have shown considerable promise for snakebite indication, with oral bioavailability particularly promising for community delivery rapidly after a snakebite. However, only two such drugs have entered clinical development for snakebite. To offset the risk of attrition during clinical trials and to better explore the chemical space for small molecule venom toxin inhibitors, here we describe the first high throughput drug screen against snake venom metalloproteinases (SVMPs)-a pathogenic toxin family responsible for causing haemorrhage and coagulopathy. Following validation of a 384-well fluorescent enzymatic assay, we screened a repurposed drug library of 3,547 compounds against five geographically distinct and toxin variable snake venoms. Our drug screen resulted in the identification of 14 compounds with pan-species inhibitory activity. Following secondary potency testing, four SVMP inhibitors were identified with nanomolar EC50s comparable to the previously identified matrix metalloproteinase inhibitor marimastat and superior to the metal chelator dimercaprol, doubling the current global portfolio of SVMP inhibitors. Following analysis of their chemical structure and ADME properties, two hit-to-lead compounds were identified. These clear starting points for the initiation of medicinal chemistry campaigns provide the basis for the first ever designer snakebite specific small molecules.
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Affiliation(s)
- Rachel H. Clare
- Department of Tropical Disease Biology, Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Tropical Disease Biology, Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Charlotte A. Dawson
- Department of Tropical Disease Biology, Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Tropical Disease Biology, Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Adam Westhorpe
- Department of Tropical Disease Biology, Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Tropical Disease Biology, Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Laura-Oana Albulescu
- Department of Tropical Disease Biology, Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Tropical Disease Biology, Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | - Nada Mosallam
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - Daniel J. W. Chong
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - Jeroen Kool
- Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Neil G. Berry
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - Paul M. O’Neill
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - Nicholas R. Casewell
- Department of Tropical Disease Biology, Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Department of Tropical Disease Biology, Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Albulescu LO, Westhorpe A, Clare RH, Woodley CM, James N, Kool J, Berry NG, O’Neill PM, Casewell NR. Optimizing drug discovery for snakebite envenoming via a high-throughput phospholipase A2 screening platform. Front Pharmacol 2024; 14:1331224. [PMID: 38273832 PMCID: PMC10808766 DOI: 10.3389/fphar.2023.1331224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Abstract
Snakebite envenoming is a neglected tropical disease that causes as many as 1.8 million envenomings and 140,000 deaths annually. To address treatment limitations that exist with current antivenoms, the search for small molecule drug-based inhibitors that can be administered as early interventions has recently gained traction. Snake venoms are complex mixtures of proteins, peptides and small molecules and their composition varies substantially between and within snake species. The phospholipases A2 (PLA2) are one of the main pathogenic toxin classes found in medically important viper and elapid snake venoms, yet varespladib, a drug originally developed for the treatment of acute coronary syndrome, remains the only PLA2 inhibitor shown to effectively neutralise venom toxicity in vitro and in vivo, resulting in an extremely limited drug portfolio. Here, we describe a high-throughput drug screen to identify novel PLA2 inhibitors for repurposing as snakebite treatments. We present method optimisation of a 384-well plate, colorimetric, high-throughput screening assay that allowed for a throughput of ∼2,800 drugs per day, and report on the screening of a ∼3,500 post-phase I repurposed drug library against the venom of the Russell's viper, Daboia russelii. We further explore the broad-spectrum inhibitory potential and efficacy of the resulting top hits against a range of medically important snake venoms and demonstrate the utility of our method in determining drug EC50s. Collectively, our findings support the future application of this method to fully explore the chemical space to discover novel PLA2-inhibiting drugs of value for preventing severe pathology caused by snakebite envenoming.
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Affiliation(s)
- Laura-Oana Albulescu
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Adam Westhorpe
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Rachel H. Clare
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | - Nivya James
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - Jeroen Kool
- Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Neil G. Berry
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - Paul M. O’Neill
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom
| | - Nicholas R. Casewell
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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8
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Thumtecho S, Burlet NJ, Ljungars A, Laustsen AH. Towards better antivenoms: navigating the road to new types of snakebite envenoming therapies. J Venom Anim Toxins Incl Trop Dis 2023; 29:e20230057. [PMID: 38116472 PMCID: PMC10729942 DOI: 10.1590/1678-9199-jvatitd-2023-0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 12/01/2023] [Indexed: 12/21/2023] Open
Abstract
Snakebite envenoming is a significant global health challenge, and for over a century, traditional plasma-derived antivenoms from hyperimmunized animals have been the primary treatment against this infliction. However, these antivenoms have several inherent limitations, including the risk of causing adverse reactions when administered to patients, batch-to-batch variation, and high production costs. To address these issues and improve treatment outcomes, the development of new types of antivenoms is crucial. During this development, key aspects such as improved clinical efficacy, enhanced safety profiles, and greater affordability should be in focus. To achieve these goals, modern biotechnological methods can be applied to the discovery and development of therapeutic agents that can neutralize medically important toxins from multiple snake species. This review highlights some of these agents, including monoclonal antibodies, nanobodies, and selected small molecules, that can achieve broad toxin neutralization, have favorable safety profiles, and can be produced on a large scale with standardized manufacturing processes. Considering the inherent strengths and limitations related to the pharmacokinetics of these different agents, a combination of them might be beneficial in the development of new types of antivenom products with improved therapeutic properties. While the implementation of new therapies requires time, it is foreseeable that the application of biotechnological advancements represents a promising trajectory toward the development of improved therapies for snakebite envenoming. As research and development continue to advance, these new products could emerge as the mainstay treatment in the future.
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Affiliation(s)
- Suthimon Thumtecho
- Division of Toxicology, Department of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, Thailand
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Nick J. Burlet
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Anne Ljungars
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Andreas H. Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
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9
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Hall SR, Rasmussen SA, Crittenden E, Dawson CA, Bartlett KE, Westhorpe AP, Albulescu LO, Kool J, Gutiérrez JM, Casewell NR. Repurposed drugs and their combinations prevent morbidity-inducing dermonecrosis caused by diverse cytotoxic snake venoms. Nat Commun 2023; 14:7812. [PMID: 38097534 PMCID: PMC10721902 DOI: 10.1038/s41467-023-43510-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 11/11/2023] [Indexed: 12/17/2023] Open
Abstract
Morbidity from snakebite envenoming affects approximately 400,000 people annually. Tissue damage at the bite-site often leaves victims with catastrophic life-long injuries and is largely untreatable by current antivenoms. Repurposed small molecule drugs that inhibit specific snake venom toxins show considerable promise for tackling this neglected tropical disease. Using human skin cell assays as an initial model for snakebite-induced dermonecrosis, we show that the drugs 2,3-dimercapto-1-propanesulfonic acid (DMPS), marimastat, and varespladib, alone or in combination, inhibit the cytotoxicity of a broad range of medically important snake venoms. Thereafter, using preclinical mouse models of dermonecrosis, we demonstrate that the dual therapeutic combinations of DMPS or marimastat with varespladib significantly inhibit the dermonecrotic activity of geographically distinct and medically important snake venoms, even when the drug combinations are delivered one hour after envenoming. These findings strongly support the future translation of repurposed drug combinations as broad-spectrum therapeutics for preventing morbidity caused by snakebite.
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Affiliation(s)
- Steven R Hall
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
- Centre for Drugs & Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Sean A Rasmussen
- Department of Pathology and Laboratory Medicine, Queen Elizabeth II Health Sciences Centre and Dalhousie University, 7th Floor of MacKenzie Building, 5788 University Avenue, Halifax, NS, B3H 1V8, Canada
| | - Edouard Crittenden
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Charlotte A Dawson
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Keirah E Bartlett
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Adam P Westhorpe
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Laura-Oana Albulescu
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
- Centre for Drugs & Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Jeroen Kool
- Division of BioAnalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands
- Centre for Analytical Sciences Amsterdam (CASA), 1098 XH, Amsterdam, The Netherlands
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, PO Box 11501-2060, San José, Costa Rica
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
- Centre for Drugs & Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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10
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Werner RM, Soffa AN. Considerations for the development of a field-based medical device for the administration of adjunctive therapies for snakebite envenoming. Toxicon X 2023; 20:100169. [PMID: 37661997 PMCID: PMC10474190 DOI: 10.1016/j.toxcx.2023.100169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/27/2023] [Accepted: 08/12/2023] [Indexed: 09/05/2023] Open
Abstract
The timely administration of antivenom is the most effective method currently available to reduce the burden of snakebite envenoming (SBE), a neglected tropical disease that most often affects rural agricultural global populations. There is increasing interest in the development of adjunctive small molecule and biologic therapeutics that target the most problematic venom components to bridge the time-gap between initial SBE and the administration antivenom. Unique combinations of these therapeutics could provide relief from the toxic effects of regional groupings of medically relevant snake species. The application a PRISMA/PICO literature search methodology demonstrated an increasing interest in the rapid administration of therapies to improve patient symptoms and outcomes after SBE. Advice from expert interviews and considerations regarding the potential routes of therapy administration, anatomical bite location, and species-specific venom delivery have provided a framework to identify ideal metrics and potential hurdles for the development of a field-based medical device that could be used immediately after SBE to deliver adjunctive therapies. The use of subcutaneous (SC) or intramuscular (IM) injection were identified as potential routes of administration of both small molecule and biologic therapies. The development of a field-based medical device for the delivery of adjunctive SBE therapies presents unique challenges that will require a collaborative and transdisciplinary approach to be successful.
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11
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Patel RN, Clare RH, Ledsgaard L, Nys M, Kool J, Laustsen AH, Ulens C, Casewell NR. An in vitro assay to investigate venom neurotoxin activity on muscle-type nicotinic acetylcholine receptor activation and for the discovery of toxin-inhibitory molecules. Biochem Pharmacol 2023; 216:115758. [PMID: 37604290 PMCID: PMC10570928 DOI: 10.1016/j.bcp.2023.115758] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023]
Abstract
Snakebite envenoming is a neglected tropical disease that causes over 100,000 deaths annually. Envenomings result in variable pathologies, but systemic neurotoxicity is among the most serious and is currently only treated with difficult to access and variably efficacious commercial antivenoms. Venom-induced neurotoxicity is often caused by α-neurotoxins antagonising the muscle-type nicotinic acetylcholine receptor (nAChR), a ligand-gated ion channel. Discovery of therapeutics targeting α-neurotoxins is hampered by relying on binding assays that do not reveal restoration of receptor activity or more costly and/or lower throughput electrophysiology-based approaches. Here, we report the validation of a screening assay for nAChR activation using immortalised TE671 cells expressing the γ-subunit containing muscle-type nAChR and a fluorescent dye that reports changes in cell membrane potential. Assay validation using traditional nAChR agonists and antagonists, which either activate or block ion fluxes, was consistent with previous studies. We then characterised antagonism of the nAChR by a variety of elapid snake venoms that cause muscle paralysis in snakebite victims, before defining the toxin-inhibiting activities of commercial antivenoms, and new types of snakebite therapeutic candidates, namely monoclonal antibodies, decoy receptors, and small molecules. Our findings show robust evidence of assay uniformity across 96-well plates and highlight the amenability of this approach for the future discovery of new snakebite therapeutics via screening campaigns. The described assay therefore represents a useful first-step approach for identifying α-neurotoxins and their inhibitors in the context of snakebite envenoming, and it should provide wider value for studying modulators of nAChR activity from other sources.
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Affiliation(s)
- Rohit N Patel
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK
| | - Rachel H Clare
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK
| | - Line Ledsgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Mieke Nys
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Belgium
| | - Jeroen Kool
- AIMMS Division of BioAnalytical Chemistry, Vrije Universiteit Amsterdam, Netherlands
| | - Andreas H Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Belgium
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK.
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12
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Wu K, Karapetyan E, Schloss J, Vadgama J, Wu Y. Advancements in small molecule drug design: A structural perspective. Drug Discov Today 2023; 28:103730. [PMID: 37536390 PMCID: PMC10543554 DOI: 10.1016/j.drudis.2023.103730] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 07/19/2023] [Accepted: 07/27/2023] [Indexed: 08/05/2023]
Abstract
In this review, we outline recent advancements in small molecule drug design from a structural perspective. We compare protein structure prediction methods and explore the role of the ligand binding pocket in structure-based drug design. We examine various structural features used to optimize drug candidates, including functional groups, stereochemistry, and molecular weight. Computational tools such as molecular docking and virtual screening are discussed for predicting and optimizing drug candidate structures. We present examples of drug candidates designed based on their molecular structure and discuss future directions in the field. By effectively integrating structural information with other valuable data sources, we can improve the drug discovery process, leading to the identification of novel therapeutics with improved efficacy, specificity, and safety profiles.
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Affiliation(s)
- Ke Wu
- Division of Cancer Research and Training, Department of Internal Medicine, Charles R. Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095, USA
| | - Eduard Karapetyan
- Division of Cancer Research and Training, Department of Internal Medicine, Charles R. Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095, USA
| | - John Schloss
- Division of Cancer Research and Training, Department of Internal Medicine, Charles R. Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095, USA; School of Pharmacy, American University of Health Sciences, Signal Hill, CA 90755, USA
| | - Jaydutt Vadgama
- Division of Cancer Research and Training, Department of Internal Medicine, Charles R. Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095, USA; School of Pharmacy, American University of Health Sciences, Signal Hill, CA 90755, USA.
| | - Yong Wu
- Division of Cancer Research and Training, Department of Internal Medicine, Charles R. Drew University of Medicine and Science, David Geffen UCLA School of Medicine and UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA 90095, USA.
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Wafula ST, Namakula LN, Ninsiima LR, Ssekamatte NK, Walekhwa AW, Mugume IB, Musoke D. Barriers and opportunities for improving management of snakebites: Perspectives of healthcare workers in Northern Uganda. PLoS One 2023; 18:e0291032. [PMID: 37747844 PMCID: PMC10519583 DOI: 10.1371/journal.pone.0291032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/20/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUND Snakebites are a neglected public health problem that pose a significant burden on affected individuals and communities in many sub-Saharan African countries, including Uganda. However, the barriers and facilitators to snakebite management within healthcare settings are not as well understood and well-documented. The aim of this study was to explore the experiences and perspectives of healthcare workers involved in handling snakebite incidents at individual and health system levels in Arua and Gulu districts in Northern Uganda. We sought to understand how healthcare workers manage snakebite cases, what challenges they encounter, and what opportunities they perceive for improvement. METHODS We conducted a qualitative study using in-depth interviews with 18 healthcare workers from different cadres, seniority levels, and facility types. We used iterative thematic analysis to explore the management procedures, challenges, and opportunities for snakebite management. Using thematic analysis, we identified the overarching themes and subthemes related to snakebite management and associated barriers and opportunities. RESULTS The main barriers to snakebite management identified by healthcare workers were inadequate knowledge and skills; limited availability of antivenom; lack of protocols for snakebite management; delayed treatment-seeking for patients; and poor referral systems. The main opportunities for improvement were regular in-service training; increasing public education and awareness about snakebite prevention and management; and increased funding and research. CONCLUSION This study highlights the need for interventions to address the identified barriers while leveraging the existing opportunities to enhance snakebite management in Uganda. Specifically, we recommend the provision of regular training and support to healthcare workers, developing clinical guidelines, and improving the availability of antivenoms.
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Affiliation(s)
- Solomon T. Wafula
- Department of Disease Control and Environmental Health, College of Health Sciences, Makerere University, Kampala, Uganda
- Department of Infectious Disease Epidemiology, Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Lydia N. Namakula
- Department of Disease Control and Environmental Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Lesley R. Ninsiima
- Department of Disease Control and Environmental Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Noah Kiwanuka Ssekamatte
- Department of Disease Control and Environmental Health, College of Health Sciences, Makerere University, Kampala, Uganda
| | - Abel W. Walekhwa
- Department of Disease Control and Environmental Health, College of Health Sciences, Makerere University, Kampala, Uganda
- Diseases Dynamics Unit, Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | | | - David Musoke
- Department of Disease Control and Environmental Health, College of Health Sciences, Makerere University, Kampala, Uganda
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Kiouas K, Oussedik-Oumehdi H, Laraba-Djebari F. Therapeutic outcome of quercetin nanoparticles on Cerastes cerastes venom-induced hepatorenal toxicity: a preclinical study. Nanomedicine (Lond) 2023; 18:367-390. [PMID: 37125660 DOI: 10.2217/nnm-2022-0188] [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: 05/02/2023] Open
Abstract
Aim: The objective of this study was to investigate the therapeutic potential of quercetin (QT) and QT-loaded poly(lactic-co-glycolic acid) nanoparticles (QT-NPs) on Cerastes cerastes venom-mediated inflammation, redox imbalance, hepatorenal tissue damage and local hemorrhage. Methods: The developed QT-NPs were first submitted to physicochemical characterization and then evaluated in the 'challenge then treat' and 'preincubation' models of envenoming. Results: QT-NPs efficiently alleviated hepatorenal toxicity, inflammation and redox imbalance and significantly attenuated venom-induced local hemorrhage. Interestingly, QT-NPs were significantly more efficient than free QT at 24 h post-envenoming, pointing to the efficacy of this drug-delivery system. Conclusion: These findings highlight the therapeutic potential of QT-NPs on venom-induced toxicity and open up the avenue for their use in the management of snakebite envenoming.
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Affiliation(s)
- Kahina Kiouas
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular & Molecular Biology, BP 32, El-Alia, Bab Ezzouar, 16111, Algiers, Algeria
| | - Habiba Oussedik-Oumehdi
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular & Molecular Biology, BP 32, El-Alia, Bab Ezzouar, 16111, Algiers, Algeria
| | - Fatima Laraba-Djebari
- USTHB, Faculty of Biological Sciences, Laboratory of Cellular & Molecular Biology, BP 32, El-Alia, Bab Ezzouar, 16111, Algiers, Algeria
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15
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Warrell DA, Williams DJ. Clinical aspects of snakebite envenoming and its treatment in low-resource settings. Lancet 2023; 401:1382-1398. [PMID: 36931290 DOI: 10.1016/s0140-6736(23)00002-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/26/2022] [Accepted: 12/18/2022] [Indexed: 03/16/2023]
Abstract
There is increasing recognition of the public health importance of snakebite envenoming. Worldwide annual incidence is likely to be 5 million bites, with mortality exceeding 150 000 deaths, and the resulting physical and psychological morbidity leads to substantial social and economic repercussions. Prevention through community education by trained health workers is the most effective and economically viable strategy for reducing risk of bites and envenoming. Clinical challenges to effective treatment are most substantial in rural areas of low-resource settings, where snakebites are most common. Classic skills of history taking, physical examination, and use of affordable point-of-care tests should be followed by monitoring of evolving local and systemic envenoming. Despite the profusion of new ideas for interventions, hyperimmune equine or ovine plasma-derived antivenoms remain the only specific treatment for snakebite envenoming. The enormous interspecies and intraspecies complexity and diversity of snake venoms, revealed by modern venomics, demands a radical redesign of many current antivenoms.
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Affiliation(s)
- David A Warrell
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; Experimental Medicine Division, John Radcliffe Hospital, Headington, UK.
| | - David J Williams
- Regulation and Prequalification Department, World Health Organization, Geneva, Switzerland
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16
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Atanga Adongo C, Anamaale Tuoyire D, Azuug M, Baffour Appiah A, Taale F, Amadu I. DECOLONISING VACCINE PRODUCTION: UNPACKING GHANAIANS’ SUPPORT FOR MADE-IN-AFRICA VACCINES. Vaccine X 2023; 14:100283. [PMID: 37008957 PMCID: PMC10064421 DOI: 10.1016/j.jvacx.2023.100283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 02/24/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
Localisation of vaccine production is essential worldwide, but it is particularly crucial for Africa. This continent is more vulnerable to disease burdens and also lags behind other continents regarding access to vaccines. Moreover, many people in Africa have a long-standing apathy towards locally made products and services. This mindset raises the question of whether Africans will support African-made vaccines and what the associated reasons are. Guided by the theories of nationalism and import substitution industrialisation, we formulated and tested eight hypotheses. To answer these, we analysed survey data from 6,731 residents backed by key informant interviews in Ghana. Our findings identified three types of local vaccine consumers: Afrocentric-ethnocentrics, Apathetic-Afrocentrics and Afrocentric-Fence Sitters. Four out of the eight hypothesised factors explain why some individuals have a positive attitude towards locally made vaccines, compared to those who are unsure of their stance. The proposed typology of local vaccine consumers and their defining characteristics can help design public health campaigns to mobilize support for locally produced vaccines.
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17
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Carter RW, Gerardo CJ, Samuel SP, Kumar S, Kotehal SD, Mukherjee PP, Shirazi FM, Akpunonu PD, Bammigatti C, Bhalla A, Manikath N, Platts-Mills TF, Lewin MR. The BRAVO Clinical Study Protocol: Oral Varespladib for Inhibition of Secretory Phospholipase A2 in the Treatment of Snakebite Envenoming. Toxins (Basel) 2022; 15:22. [PMID: 36668842 PMCID: PMC9862656 DOI: 10.3390/toxins15010022] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/19/2022] [Accepted: 12/24/2022] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION Snakebite is an urgent, unmet global medical need causing significant morbidity and mortality worldwide. Varespladib is a potent inhibitor of venom secretory phospholipase A2 (sPLA2) that can be administered orally via its prodrug, varespladib-methyl. Extensive preclinical data support clinical evaluation of varespladib as a treatment for snakebite envenoming (SBE). The protocol reported here was designed to evaluate varespladib-methyl for SBE from any snake species in multiple geographies. METHODS AND ANALYSIS BRAVO (Broad-spectrum Rapid Antidote: Varespladib Oral for snakebite) is a multicenter, randomized, double-blind, placebo-controlled, phase 2 study to evaluate the safety, tolerability, and efficacy of oral varespladib-methyl plus standard of care (SoC) vs. SoC plus placebo in patients presenting with acute SBE by any venomous snake species. Male and female patients 5 years of age and older who meet eligibility criteria will be randomly assigned 1:1 to varespladib-methyl or placebo. The primary outcome is the Snakebite Severity Score (SSS) that has been modified for international use. This composite outcome is based on the sum of the pulmonary, cardiovascular, nervous, hematologic, and renal systems components of the updated SSS. ETHICS AND DISSEMINATION This protocol was submitted to regulatory authorities in India and the US. A Clinical Trial No Objection Certificate from the India Central Drugs Standard Control Organisation, Drug Controller General-India, and a Notice to Proceed from the US Food and Drug Administration have been obtained. The study protocol was approved by properly constituted, valid institutional review boards or ethics committees at each study site. This study is being conducted in compliance with the April 1996 ICH Guidance for Industry GCP E6, the Integrated Addendum to ICH E6 (R2) of November 2016, and the applicable regulations of the country in which the study is conducted. The trial is registered on Clinical trials.gov, NCT#04996264 and Clinical Trials Registry-India, 2021/07/045079 000062.
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Affiliation(s)
| | - Charles J. Gerardo
- Department of Emergency Medicine, Duke University, Durham, NC 27708, USA
| | | | - Surendra Kumar
- Department of Medicine, Sardar Patel Medical College, PBM Hospital, Bikaner 334001, India
| | - Suneetha D. Kotehal
- Department of Medicine, Mysore Medical College and Research Institute, Mysore 570001, India
| | - Partha P. Mukherjee
- Department of General Medicine, Calcutta National Medical College, Kolkata 700014, India
| | - Farshad M. Shirazi
- Arizona Poison & Drug Information Center, College of Pharmacy and University of Arizona College of Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Peter D. Akpunonu
- Department of Emergency Medicine and Medical Toxicology, University of Kentucky College of Medicine, Lexington, KY 40506, USA
| | - Chanaveerappa Bammigatti
- Department of Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry 605006, India
| | - Ashish Bhalla
- Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Neeraj Manikath
- Department of Emergency Medicine, Government Medical College, Kozhikode 673008, India
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Varespladib in the Treatment of Snakebite Envenoming: Development History and Preclinical Evidence Supporting Advancement to Clinical Trials in Patients Bitten by Venomous Snakes. Toxins (Basel) 2022; 14:toxins14110783. [PMID: 36422958 PMCID: PMC9695340 DOI: 10.3390/toxins14110783] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/26/2022] [Accepted: 11/01/2022] [Indexed: 11/16/2022] Open
Abstract
The availability of effective, reliably accessible, and affordable treatments for snakebite envenoming is a critical and long unmet medical need. Recently, small, synthetic toxin-specific inhibitors with oral bioavailability used in conjunction with antivenom have been identified as having the potential to greatly improve outcomes after snakebite. Varespladib, a small, synthetic molecule that broadly and potently inhibits secreted phospholipase A2 (sPLA2s) venom toxins has renewed interest in this class of inhibitors due to its potential utility in the treatment of snakebite envenoming. The development of varespladib and its oral dosage form, varespladib-methyl, has been accelerated by previous clinical development campaigns to treat non-envenoming conditions related to ulcerative colitis, rheumatoid arthritis, asthma, sepsis, and acute coronary syndrome. To date, twenty-nine clinical studies evaluating the safety, pharmacokinetics (PK), and efficacy of varespladib for non-snakebite envenoming conditions have been completed in more than 4600 human subjects, and the drugs were generally well-tolerated and considered safe for use in humans. Since 2016, more than 30 publications describing the structure, function, and efficacy of varespladib have directly addressed its potential for the treatment of snakebite. This review summarizes preclinical findings and outlines the scientific support, the potential limitations, and the next steps in the development of varespladib's use as a snakebite treatment, which is now in Phase 2 human clinical trials in the United States and India.
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Alomran N, Chinnappan R, Alsolaiss J, Casewell NR, Zourob M. Exploring the Utility of ssDNA Aptamers Directed against Snake Venom Toxins as New Therapeutics for Snakebite Envenoming. Toxins (Basel) 2022; 14:469. [PMID: 35878207 PMCID: PMC9318713 DOI: 10.3390/toxins14070469] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/04/2022] [Accepted: 07/06/2022] [Indexed: 11/23/2022] Open
Abstract
Snakebite is a neglected tropical disease that causes considerable death and disability in the tropical world. Although snakebite can cause a variety of pathologies in victims, haemotoxic effects are particularly common and are typically characterised by haemorrhage and/or venom-induced consumption coagulopathy. Antivenoms are the mainstay therapy for treating the toxic effects of snakebite, but despite saving thousands of lives annually, these therapies are associated with limited cross-snake species efficacy due to venom variation, which ultimately restricts their therapeutic utility to particular geographical regions. In this study, we sought to explore the potential of ssDNA aptamers as toxin-specific inhibitory alternatives to antibodies. As a proof of principle model, we selected snake venom serine protease toxins, which are responsible for contributing to venom-induced coagulopathy following snakebite envenoming, as our target. Using SELEX technology, we selected ssDNA aptamers against recombinantly expressed versions of the fibrinogenolytic SVSPs ancrod from the venom of C. rhodostoma and batroxobin from B. atrox. From the resulting pool of specific ssDNA aptamers directed against each target, we identified candidates that exhibited low nanomolar binding affinities to their targets. Downstream aptamer-linked immobilised sorbent assay, fibrinogenolysis, and coagulation profiling experiments demonstrated that the candidate aptamers were able to recognise native and recombinant SVSP toxins and inhibit the toxin- and venom-induced prolongation of plasma clotting times and the consumption of fibrinogen, with inhibitory potencies highly comparable to commercial polyvalent antivenoms. Our findings demonstrate that rationally selected toxin-specific aptamers can exhibit broad in vitro cross-reactivity against toxin isoforms found in different snake venoms and are capable of inhibiting toxins in pathologically relevant in vitro and ex vivo models of venom activity. These data highlight the potential utility of ssDNA aptamers as novel toxin-inhibiting therapeutics of value for tackling snakebite envenoming.
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Affiliation(s)
- Nessrin Alomran
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (N.A.); (J.A.)
| | - Raja Chinnappan
- Department of Chemistry, Alfaisal University, Al Zahrawi Street, Al Maather, Al Takhassusi Road, Riyadh 11533, Saudi Arabia;
- King Faisal Specialist Hospital and Research Center, Zahrawi Street, Al Maather, Riyadh 12713, Saudi Arabia
| | - Jaffer Alsolaiss
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (N.A.); (J.A.)
| | - Nicholas R. Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (N.A.); (J.A.)
- Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Mohammed Zourob
- Department of Chemistry, Alfaisal University, Al Zahrawi Street, Al Maather, Al Takhassusi Road, Riyadh 11533, Saudi Arabia;
- King Faisal Specialist Hospital and Research Center, Zahrawi Street, Al Maather, Riyadh 12713, Saudi Arabia
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Menzies SK, Clare RH, Xie C, Westhorpe A, Hall SR, Edge RJ, Alsolaiss J, Crittenden E, Marriott AE, Harrison RA, Kool J, Casewell NR. In vitro and in vivo preclinical venom inhibition assays identify metalloproteinase inhibiting drugs as potential future treatments for snakebite envenoming by Dispholidus typus. Toxicon X 2022; 14:100118. [PMID: 35321116 PMCID: PMC8935517 DOI: 10.1016/j.toxcx.2022.100118] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/18/2022] [Accepted: 03/07/2022] [Indexed: 11/23/2022] Open
Abstract
Snakebite envenoming affects more than 250,000 people annually in sub-Saharan Africa. Envenoming by Dispholidus typus (boomslang) results in venom-induced consumption coagulopathy (VICC), whereby highly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogen. The only available treatment for D. typus envenoming is the monovalent SAIMR Boomslang antivenom. Treatment options are urgently required because this antivenom is often difficult to source and, at US$6000/vial, typically unaffordable for most snakebite patients. We therefore investigated the in vitro and in vivo preclinical efficacy of four SVMP inhibitors to neutralise the effects of D. typus venom; the matrix metalloproteinase inhibitors marimastat and prinomastat, and the metal chelators dimercaprol and DMPS. The venom of D. typus exhibited an SVMP-driven procoagulant phenotype in vitro. Marimastat and prinomastat demonstrated equipotent inhibition of the SVMP-mediated procoagulant activity of the venom in vitro, whereas dimercaprol and DMPS showed considerably lower potency. However, when tested in preclinical murine models of envenoming using mixed sex CD1 mice, DMPS and marimastat demonstrated partial protection against venom lethality, demonstrated by prolonged survival times of experimental animals, whereas dimercaprol and prinomastat failed to confer any protection at the doses tested. The preclinical results presented here demonstrate that DMPS and marimastat show potential as novel small molecule-based therapeutics for D. typus snakebite envenoming. These two drugs have been previously shown to be effective against Echis ocellatus VICC in preclinical models, and thus we conclude that marimastat and DMPS should be further explored as potentially valuable early intervention therapeutics to broadly treat VICC following snakebite envenoming in sub-Saharan Africa.
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Affiliation(s)
- Stefanie K. Menzies
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Rachel H. Clare
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Chunfang Xie
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081HV, Amsterdam, the Netherlands
| | - Adam Westhorpe
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Steven R. Hall
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Rebecca J. Edge
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Jaffer Alsolaiss
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Edouard Crittenden
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Amy E. Marriott
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Robert A. Harrison
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
| | - Jeroen Kool
- Amsterdam Institute of Molecular and Life Sciences, Division of BioAnalytical Chemistry, Department of Chemistry and Pharmaceutical Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081HV, Amsterdam, the Netherlands
| | - Nicholas R. Casewell
- Centre for Snakebite Research and Interventions, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
- Centre for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, England, UK
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A comparative study of endogenous phospholipase A 2 inhibitors in the serum of Brazilian pit vipers. Toxicon 2022; 213:87-91. [PMID: 35487313 DOI: 10.1016/j.toxicon.2022.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 11/20/2022]
Abstract
This work compared the presence of phospholipase A2 inhibitors (PLIs) in the serum of 19 snake species maintained at Instituto Butantan to better understand the mechanisms of venom resistance in snakes and improve the treatment of snakebite. PLI was isolated from blood of 19 snake species by one-step chromatography and identified in all samples, besides its identity was confirmed through the interaction with both phospholipase A2 and anti-γPLI. These findings highlight the diversity of snake serum PLIs and emphasize the importance of structure-function studies.
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Hayashi MAF, Campeiro JD, Yonamine CM. Revisiting the potential of South American rattlesnake Crotalus durissus terrificus toxins as therapeutic, theranostic and/or biotechnological agents. Toxicon 2021; 206:1-13. [PMID: 34896407 DOI: 10.1016/j.toxicon.2021.12.005] [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] [Received: 09/09/2021] [Revised: 11/10/2021] [Accepted: 12/08/2021] [Indexed: 02/07/2023]
Abstract
The potential biotechnological and biomedical applications of the animal venom components are widely recognized. Indeed, many components have been used either as drugs or as templates/prototypes for the development of innovative pharmaceutical drugs, among which many are still used for the treatment of human diseases. A specific South American rattlesnake, named Crotalus durissus terrificus, shows a venom composition relatively simpler compared to any viper or other snake species belonging to the Crotalus genus, although presenting a set of toxins with high potential for the treatment of several still unmet human therapeutic needs, as reviewed in this work. In addition to the main toxin named crotoxin, which is under clinical trials studies for antitumoral therapy and which has also anti-inflammatory and immunosuppressive activities, other toxins from the C. d. terrificus venom are also being studied, aiming for a wide variety of therapeutic applications, including as antinociceptive, anti-inflammatory, antimicrobial, antifungal, antitumoral or antiparasitic agent, or as modulator of animal metabolism, fibrin sealant (fibrin glue), gene carrier or theranostic agent. Among these rattlesnake toxins, the most relevant, considering the potential clinical applications, are crotamine, crotalphine and gyroxin. In this narrative revision, we propose to organize and present briefly the updates in the accumulated knowledge on potential therapeutic applications of toxins collectively found exclusively in the venom of this specific South American rattlesnake, with the objective of contributing to increase the chances of success in the discovery of drugs based on toxins.
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Affiliation(s)
- Mirian A F Hayashi
- Department of Pharmacology, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP), SP, Brazil.
| | - Joana D Campeiro
- Department of Pharmacology, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP), SP, Brazil
| | - Camila M Yonamine
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP), SP, Brazil.
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Puzari U, Fernandes PA, Mukherjee AK. Advances in the Therapeutic Application of Small-Molecule Inhibitors and Repurposed Drugs against Snakebite. J Med Chem 2021; 64:13938-13979. [PMID: 34565143 DOI: 10.1021/acs.jmedchem.1c00266] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The World Health Organization has declared snakebite as a neglected tropical disease. Antivenom administration is the sole therapy against venomous snakebite; however, several limitations of this therapy reinforce the dire need for an alternative and/or additional treatment against envenomation. Inhibitors against snake venoms have been explored from natural resources and are synthesized in the laboratory; however, repurposing of small-molecule therapeutics (SMTs) against the principal toxins of snake venoms to inhibit their lethality and/or obnoxious effect of envenomation has been garnering greater attention owing to their established pharmacokinetic properties, low-risk attributes, cost-effectiveness, ease of administration, and storage stability. Nevertheless, SMTs are yet to be approved and commercialized for snakebite treatment. Therefore, we have systematically reviewed and critically analyzed the scenario of small synthetic inhibitors and repurposed drugs against snake envenomation from 2005 to date and proposed novel approaches and commercialization strategies for the development of efficacious therapies against snake envenomation.
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Affiliation(s)
- Upasana Puzari
- Department of Molecular Biology and Biotechnology, School of Sciences, Tezpur University, Tezpur-784028, Assam, India
| | - Pedro Alexandrino Fernandes
- LAQV@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua Do Campo Alegre S/N, 4169-007 Porto, Portugal
| | - Ashis K Mukherjee
- Department of Molecular Biology and Biotechnology, School of Sciences, Tezpur University, Tezpur-784028, Assam, India.,Institute of Advanced Study in Science and Technology, Vigyan Path Garchuk, Paschim Boragaon, Guwahati-781035, Assam, India
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24
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Martins D, Potet J, Ribeiro I. Snakebites and COVID-19: two crises, one research and development opportunity. BMJ Glob Health 2021; 6:e006913. [PMID: 34697086 PMCID: PMC8557241 DOI: 10.1136/bmjgh-2021-006913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/13/2021] [Indexed: 12/31/2022] Open
Affiliation(s)
- Diogo Martins
- Snakebites Priority Area, Wellcome Trust, London, UK
- Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London, UK
| | - Julien Potet
- Neglected Tropical Diseases Advisor, Médecins Sans Frontières Access Campaign, Geneva, Switzerland
| | - Isabela Ribeiro
- Research and Development - Dynamic Portfolio Unit, Drugs for Neglected Diseases initiative, Geneva, Switzerland
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Mukherjee AK, Mackessy SP. Prevention and improvement of clinical management of snakebite in Southern Asian countries: A proposed road map. Toxicon 2021; 200:140-152. [PMID: 34280412 DOI: 10.1016/j.toxicon.2021.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 07/10/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
In the Southern Asian countries, snakebite takes a substantial toll in terms of human life, inflicts acute morbidity and long term disability both physical and psychological, and therefore represents a neglected socio-economic problem and severe health issue that requires immediate medical attention. The 'Big Four' venomous snakes, viz. Daboia russelii, Naja naja, Bungarus caeruleus and Echis carinatus, are prominent, medically important species and are the most dangerous snakes of this region; therefore, the commercial polyvalent antivenom (PAV) contains antibodies against the venoms of these snakes. However, envenomations by species other than the 'Big Four' snakes are grossly neglected, and PAV is only partially effective in neutralizing the venom of these snakes. Many issues confounding effective treatment of snakebite are discussed in this review, and these hurdles preventing successful treatment of snakebite must be addressed. However, in South Asian countries, the pre-hospital treatment and appropriate first aid are equally important to mitigate the problem of snakebite and therefore, these issues are also highlighted here. Further, this review suggests a roadmap and guidelines for the prevention of snakebite and improvement of hospital management of snakebite in these Southern Asian countries.
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Affiliation(s)
- Ashis K Mukherjee
- Division of Life Sciences, Institute of Advanced Study in Science and Technology, Vigyan Path Garchuk, Paschim Boragaon, Guwahati, 781035, Assam, India; Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, 78028, Assam, India; School of Biological Sciences, University of Northern Colorado, Greeley, CO, 80639-0017, USA.
| | - Stephen P Mackessy
- School of Biological Sciences, University of Northern Colorado, Greeley, CO, 80639-0017, USA
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Hamza M, Knudsen C, Gnanathasan CA, Monteiro W, Lewin MR, Laustsen AH, Habib AG. Clinical management of snakebite envenoming: Future perspectives. Toxicon X 2021; 11:100079. [PMID: 34430847 PMCID: PMC8374517 DOI: 10.1016/j.toxcx.2021.100079] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 06/29/2021] [Accepted: 07/30/2021] [Indexed: 11/18/2022] Open
Abstract
Snakebite envenoming is a major cause of morbidity and mortality in rural communities throughout the tropics. Generally, the main clinical features of snakebites are local swelling, tissue necrosis, shock, spontaneous systemic hemorrhage, incoagulable blood, paralysis, rhabdomyolysis, and acute kidney injury. These clinical manifestations result from complex biochemical venom constituents comprising of cytotoxins, hemotoxins, neurotoxins, myotoxins, and other substances. Timely diagnosis of envenoming and identification of the responsible snake species is clinically challenging in many parts of the world and necessitates prompt and thorough clinical assessment, which could be supported by the development of reliable, affordable, widely-accessible, point-of-care tests. Conventional antivenoms based on polyclonal antibodies derived from animals remain the mainstay of therapy along with supportive medical and surgical care. However, while antivenoms save countless lives, they are associated with adverse reactions, limited potency, and are relatively inefficacious against presynaptic neurotoxicity and in preventing necrosis. Nevertheless, major scientific and technological advances are facilitating the development of new molecular and immunologic diagnostic tests, as well as a new generation of antivenoms comprising human monoclonal antibodies with broader and more potent neutralization capacity and less immunogenicity. Repurposed pharmaceuticals based on small molecule inhibitors (e.g., marimastat and varespladib) used alone and in combination against enzymatic toxins, such as metalloproteases and phospholipase A2s, have shown promise in animal studies. These orally bioavailable molecules could serve as early interventions in the out-of-hospital setting if confirmed to be safe and efficacious in clinical studies. Antivenom access can be improved by the usage of drones and ensuring constant antivenom supply in remote endemic rural areas. Overall, the improvement of clinical management of snakebite envenoming requires sustained, coordinated, and multifaceted efforts involving basic and applied sciences, new technology, product development, effective clinical training, implementation of existing guidelines and therapeutic approaches, supported by improved supply of existing antivenoms.
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Affiliation(s)
- Muhammad Hamza
- Infectious and Tropical Diseases Unit, Bayero University Kano, Nigeria
| | - Cecilie Knudsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Wuelton Monteiro
- Department of Research, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
- School of Health Sciences, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Matthew R. Lewin
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, USA
| | - Andreas H. Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
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Gutiérrez JM, Albulescu LO, Clare RH, Casewell NR, Abd El-Aziz TM, Escalante T, Rucavado A. The Search for Natural and Synthetic Inhibitors That Would Complement Antivenoms as Therapeutics for Snakebite Envenoming. Toxins (Basel) 2021; 13:451. [PMID: 34209691 PMCID: PMC8309910 DOI: 10.3390/toxins13070451] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 06/23/2021] [Accepted: 06/27/2021] [Indexed: 12/28/2022] Open
Abstract
A global strategy, under the coordination of the World Health Organization, is being unfolded to reduce the impact of snakebite envenoming. One of the pillars of this strategy is to ensure safe and effective treatments. The mainstay in the therapy of snakebite envenoming is the administration of animal-derived antivenoms. In addition, new therapeutic options are being explored, including recombinant antibodies and natural and synthetic toxin inhibitors. In this review, snake venom toxins are classified in terms of their abundance and toxicity, and priority actions are being proposed in the search for snake venom metalloproteinase (SVMP), phospholipase A2 (PLA2), three-finger toxin (3FTx), and serine proteinase (SVSP) inhibitors. Natural inhibitors include compounds isolated from plants, animal sera, and mast cells, whereas synthetic inhibitors comprise a wide range of molecules of a variable chemical nature. Some of the most promising inhibitors, especially SVMP and PLA2 inhibitors, have been developed for other diseases and are being repurposed for snakebite envenoming. In addition, the search for drugs aimed at controlling endogenous processes generated in the course of envenoming is being pursued. The present review summarizes some of the most promising developments in this field and discusses issues that need to be considered for the effective translation of this knowledge to improve therapies for tackling snakebite envenoming.
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Affiliation(s)
- José María Gutiérrez
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José 11501, Costa Rica; (T.E.); (A.R.)
| | - Laura-Oana Albulescu
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; (L.-O.A.); (R.H.C.); (N.R.C.)
| | - Rachel H. Clare
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; (L.-O.A.); (R.H.C.); (N.R.C.)
| | - Nicholas R. Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; (L.-O.A.); (R.H.C.); (N.R.C.)
| | - Tarek Mohamed Abd El-Aziz
- Zoology Department, Faculty of Science, Minia University, El-Minia 61519, Egypt;
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
| | - Teresa Escalante
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José 11501, Costa Rica; (T.E.); (A.R.)
| | - Alexandra Rucavado
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José 11501, Costa Rica; (T.E.); (A.R.)
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