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Murphy K, Tasoulis T, Dunstan N, Isbister GK. Anticoagulant activity in Australasian elapid snake venoms and neutralisation with antivenom and varespladib. Toxicon 2024; 247:107836. [PMID: 38945217 DOI: 10.1016/j.toxicon.2024.107836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 06/04/2024] [Accepted: 06/25/2024] [Indexed: 07/02/2024]
Abstract
The venoms of Australasian elapid snakes are known to possess coagulant activity, including some with strong procoagulant activity and others with anticoagulant activity, although the latter are less well known. This study investigates the anticoagulant activity of Australasian elapid snake venoms, and whether this activity is neutralised by commercial snake antivenom and varespladib (PLA2 inhibiting agent). Clotting assays were completed for 34 species of Australasian elapids. Antivenom neutralisation assays with tiger snake antivenom (TSAV) were performed on five species to determine if there was cross-neutralisation. Varespladib neutralisation assays were also completed for the same five species. All Pseudechis species venoms had anticoagulant activity, except P. porphyriacus, which was procoagulant. Pseudechis species venoms had similar anticoagulant potency ranging from the most potent P. colletti venom to the least potent P. butleri venom. The three Austrelaps (copperhead) species venoms were the next most potent anticoagulants. Six further snakes, Elapognathus coronatus, Acanthophis pyrrhus, A. antarcticus, Suta suta, Denisonia devisi and D. maculata, had weaker anticoagulant activity, except for D. maculata which had similar anticoagulant activity to Pseudechis species. Tiger Snake Antivenom (1200mU/mL) neutralised the anticoagulant effect of P. australis for concentrations up to 1 mg/mL. TSAV (1200mU/mL) also neutralised P. colletti, D. maculata, A. superbus and A. pyrrhus venoms at their EC50, demonstrating cross neutralisation. Varespladib neutralised the anticoagulant effect of P. australis venom at 5 μM and for venoms of P. colletti, D. maculata, A. superbus and A. pyrrhus. We found anticoagulant activity to be present in six genera of Australasian snakes at low concentrations, which can be completely neutralised by both antivenom and varespladib. Anticoagulant activity in Australian elapid venoms was associated with species possessing high PLA2 activity without procoagulant snake venom serine proteases.
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Affiliation(s)
- Kate Murphy
- Clinical Toxicology Research Group, University of Newcastle, New South Wales, Australia
| | - Theo Tasoulis
- Clinical Toxicology Research Group, University of Newcastle, New South Wales, Australia
| | | | - Geoffrey K Isbister
- Clinical Toxicology Research Group, University of Newcastle, New South Wales, Australia; Department of Clinical Toxicology, Calvary Mater Newcastle, New South Wales, Australia.
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Sampat GH, Hiremath K, Dodakallanavar J, Patil VS, Harish DR, Biradar P, Mahadevamurthy RK, Barvaliya M, Roy S. Unraveling snake venom phospholipase A 2: an overview of its structure, pharmacology, and inhibitors. Pharmacol Rep 2023; 75:1454-1473. [PMID: 37926795 DOI: 10.1007/s43440-023-00543-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 11/07/2023]
Abstract
Snake bite is a neglected disease that affects millions of people worldwide. WHO reported approximately 5 million people are bitten by various species of snakes each year, resulting in nearly 1 million deaths and an additional three times cases of permanent disability. Snakes utilize the venom mainly for immobilization and digestion of their prey. Snake venom is a composition of proteins and enzymes which is responsible for its diverse pharmacological action. Snake venom phospholipase A2 (SvPLA2) is an enzyme that is present in every snake species in different quantities and is known to produce remarkable functional diversity and pharmacological action like inflammation, necrosis, myonecrosis, hemorrhage, etc. Arachidonic acid, a precursor to eicosanoids, such as prostaglandins and leukotrienes, is released when SvPLA2 catalyzes the hydrolysis of the sn-2 positions of membrane glycerophospholipids, which is responsible for its actions. Polyvalent antivenom produced from horses or lambs is the standard treatment for snake envenomation, although it has many drawbacks. Traditional medical practitioners treat snake bites using plants and other remedies as a sustainable alternative. More than 500 plant species from more than 100 families reported having venom-neutralizing abilities. Plant-derived secondary metabolites have the ability to reduce the venom's adverse consequences. Numerous studies have documented the ability of plant chemicals to inhibit the enzymes found in snake venom. Research in recent years has shown that various small molecules, such as varespladib and methyl varespladib, effectively inhibit the PLA2 toxin. In the present article, we have overviewed the knowledge of snake venom phospholipase A2, its classification, and the mechanism involved in the pathophysiology of cytotoxicity, myonecrosis, anticoagulation, and inflammation clinical application and inhibitors of SvPLA2, along with the list of studies carried out to evaluate the potency of small molecules like varespladib and secondary metabolites from the traditional medicine for their anti-PLA2 effect.
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Affiliation(s)
- Ganesh H Sampat
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnataka, 590010, India
- KLE College of Pharmacy, Belagavi, KLE Academy of Higher Education and Research, Belagavi, Karnataka, 590010, India
| | - Kashinath Hiremath
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnataka, 590010, India
- KLE College of Pharmacy, Belagavi, KLE Academy of Higher Education and Research, Belagavi, Karnataka, 590010, India
| | - Jagadeesh Dodakallanavar
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnataka, 590010, India
- KLE College of Pharmacy, Belagavi, KLE Academy of Higher Education and Research, Belagavi, Karnataka, 590010, India
| | - Vishal S Patil
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnataka, 590010, India
- KLE College of Pharmacy, Belagavi, KLE Academy of Higher Education and Research, Belagavi, Karnataka, 590010, India
| | - Darasaguppe R Harish
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnataka, 590010, India.
| | - Prakash Biradar
- KLE College of Pharmacy, Belagavi, KLE Academy of Higher Education and Research, Belagavi, Karnataka, 590010, India.
| | | | - Manish Barvaliya
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnataka, 590010, India
| | - Subarna Roy
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnataka, 590010, India
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Salvador GHM, Pinto ÊKR, Ortolani PL, Fortes-Dias CL, Cavalcante WLG, Soares AM, Lomonte B, Lewin MR, Fontes MRM. Structural basis of the myotoxic inhibition of the Bothrops pirajai PrTX-I by the synthetic varespladib. Biochimie 2023; 207:1-10. [PMID: 36403756 DOI: 10.1016/j.biochi.2022.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
Varespladib (LY315920) is a potent inhibitor of human group IIA phospholipase A2 (PLA2) originally developed to control inflammatory cascades of diseases associated with high or dysregulated levels of endogenous PLA2. Recently, varespladib was also found to inhibit snake venom PLA2 and PLA2-like toxins. Herein, ex vivo neuromuscular blocking activity assays were used to test the inhibitory activity of varespladib. The binding affinity between varespladib and a PLA2-like toxin was quantified and compared with other potential inhibitors for this class of proteins. Crystallographic and bioinformatic studies showed that varespladib binds to PrTX-I and BthTX-I into their hydrophobic channels, similarly to other previously characterized PLA2-like myotoxins. However, a new finding is that an additional varespladib binds to the MDiS region, a particular site that is related to muscle cell disruption by these toxins. The present results further advance the characterization of the molecular interactions of varespladib with PLA2-like myotoxins and provide additional evidence for this compound as a promising inhibitor candidate for different PLA2 and PLA2-like toxins.
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Affiliation(s)
- Guilherme H M Salvador
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Êmylle K R Pinto
- Departmento de Farmacologia, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais (UFMG), Brazil
| | - Paula L Ortolani
- Centro de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias (FUNED), Brazil
| | | | - Walter L G Cavalcante
- Departmento de Farmacologia, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais (UFMG), Brazil
| | - Andreimar M Soares
- Laboratório de Biotecnologia de Proteínas e Compostos Bioativos Aplicados à Saúde, LABIOPROT, Fundação Oswaldo Cruz, FIOCRUZ, unidade Rondônia e Instituto Nacional de Ciência e Tecnologia de Epidemiologia da Amazônia Ocidental, INCT EPIAMO, Porto Velho, RO, Brazil
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Matthew R Lewin
- Ophirex, Inc. Corte Madera, CA, 94925, USA; Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA, 94118, USA
| | - Marcos R M Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil.
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Zambelli VO, Hösch NG, Farom S, Zychar BC, Spadacci-Morena DD, Carvalho LV, Curi R, Lepsch LB, Scavone C, Sant'Anna OA, Gonçalves LRC, Cury Y, Sampaio SC. Formyl peptide receptors are involved in CTX-induced impairment of lymphocyte functions. Toxicon 2023; 222:106986. [PMID: 36442690 DOI: 10.1016/j.toxicon.2022.106986] [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: 09/28/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 11/27/2022]
Abstract
Crotoxin (CTX) is a neurotoxin that is isolated from the venom of Crotalus durissus terrificus, which displays immunomodulatory, anti-inflammatory, and anti-tumoral effects. Previous research has demonstrated that CTX promotes the adherence of leukocytes to the endothelial cells in blood microcirculation and the high endothelial venules of lymph nodes, which reduces the number of blood cells and lymphocytes. Studies have also shown that these effects are mediated by lipoxygenase-derived mediators. However, the exact lipoxygenase-derived eicosanoid involved in the CTX effect on lymphocytes is yet to be characterized. As CTX stimulates lipoxin-derived mediators from macrophages and lymphocyte effector functions could be modulated by activating formyl peptide receptors, we aimed to investigate whether these receptors were involved in CTX-induced redistribution and functions of lymphocytes in rats. We used male Wistar rats treated with CTX to demonstrate that Boc2 (butoxycarbonyl-Phe-Leu-Phe-Leu-Phe), an antagonist of formyl peptide receptors, prevented CTX-induced decrease in the number of circulating lymphocytes and increased the expression of the lymphocyte adhesion molecule LFA1. CTX reduced the T and B lymphocyte functions, such as lymphocyte proliferation in response to the mitogen Concanavalin A and antibody production in response to BSA immunization, respectively, which was prevented by the administration of Boc2. Importantly, mesenteric lymph node lymphocytes from CTX-treated rats showed an increased release of 15-epi-LXA4. These results indicate that formyl peptide receptors mediate CTX-induced redistribution of lymphocytes and that 15-epi-LXA4 is a key mediator of the immunosuppressive effects of CTX.
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Affiliation(s)
- Vanessa O Zambelli
- Laboratory of Pain and Signaling, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil.
| | - Natália Gabriele Hösch
- Laboratory of Pain and Signaling, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Sarah Farom
- Laboratory of Pain and Signaling, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil; Laboratory of Pathophysiology, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Bianca C Zychar
- Laboratory of Pathophysiology, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Diva D Spadacci-Morena
- Laboratory of Pathophysiology, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Luciana Vieira Carvalho
- Laboratory of Immunochemistry, Butantan Institute, Av. Vital Brasil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Rui Curi
- Immunobiological Production Section, Bioindustrial Center, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil; Interdisciplinary Post-graduate Program in Health Sciences, Cruzeiro of Sul University, São Paulo, SP, Brazil
| | - Lucilia B Lepsch
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, 05508-900, Brazil
| | - Cristoforo Scavone
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, 05508-900, Brazil
| | - Osvaldo Augusto Sant'Anna
- Laboratory of Immunochemistry, Butantan Institute, Av. Vital Brasil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Luís Roberto C Gonçalves
- Laboratory of Pathophysiology, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Yara Cury
- Laboratory of Pain and Signaling, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil
| | - Sandra C Sampaio
- Laboratory of Pathophysiology, Butantan Institute, Av. Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil.
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In Vitro Efficacy of Antivenom and Varespladib in Neutralising Chinese Russell's Viper ( Daboia siamensis) Venom Toxicity. Toxins (Basel) 2023; 15:toxins15010062. [PMID: 36668882 PMCID: PMC9864994 DOI: 10.3390/toxins15010062] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
The venom of the Russell's viper (Daboia siamensis) contains neurotoxic and myotoxic phospholipase A2 toxins which can cause irreversible damage to motor nerve terminals. Due to the time delay between envenoming and antivenom administration, antivenoms may have limited efficacy against some of these venom components. Hence, there is a need for adjunct treatments to circumvent these limitations. In this study, we examined the efficacy of Chinese D. siamensis antivenom alone, and in combination with a PLA2 inhibitor, Varespladib, in reversing the in vitro neuromuscular blockade in the chick biventer cervicis nerve-muscle preparation. Pre-synaptic neurotoxicity and myotoxicity were not reversed by the addition of Chinese D. siamensis antivenom 30 or 60 min after venom (10 µg/mL). The prior addition of Varespladib prevented the neurotoxic and myotoxic activity of venom (10 µg/mL) and was also able to prevent further reductions in neuromuscular block and muscle twitches when added 60 min after venom. The addition of the combination of Varespladib and antivenom 60 min after venom failed to produce further improvements than Varespladib alone. This demonstrates that the window of time in which antivenom remains effective is relatively short compared to Varespladib and small-molecule inhibitors may be effective in abrogating some activities of Chinese D. siamensis venom.
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Biological and Medical Aspects Related to South American Rattlesnake Crotalus durissus (Linnaeus, 1758): A View from Colombia. Toxins (Basel) 2022; 14:toxins14120875. [PMID: 36548772 PMCID: PMC9784998 DOI: 10.3390/toxins14120875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/25/2022] [Accepted: 12/03/2022] [Indexed: 12/16/2022] Open
Abstract
In Colombia, South America, there is a subspecies of the South American rattlesnake Crotalus durissus, C. d. cumanensis, a snake of the Viperidae family, whose presence has been reduced due to the destruction of its habitat. It is an enigmatic snake from the group of pit vipers, venomous, with large articulated front fangs, special designs on its body, and a characteristic rattle on its tail. Unlike in Brazil, the occurrence of human envenomation by C. durisus in Colombia is very rare and contributes to less than 1% of envenomation caused by snakes. Its venom is a complex cocktail of proteins with different biological effects, which evolved with the purpose of paralyzing the prey, killing it, and starting its digestive process, as well as having defense functions. When its venom is injected into humans as the result of a bite, the victim presents with both local tissue damage and with systemic involvement, including a diverse degree of neurotoxic, myotoxic, nephrotoxic, and coagulopathic effects, among others. Its biological effects are being studied for use in human health, including the possible development of analgesic, muscle relaxant, anti-inflammatory, immunosuppressive, anti-infection, and antineoplastic drugs. Several groups of researchers in Brazil are very active in their contributions in this regard. In this work, a review is made of the most relevant biological and medical aspects related to the South American rattlesnake and of what may be of importance for a better understanding of the snake C. d. cumanensis, present in Colombia and Venezuela.
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Quiroz S, Henao Castañeda IC, Granados J, Patiño AC, Preciado LM, Pereañez JA. Inhibitory Effects of Varespladib, CP471474, and Their Potential Synergistic Activity on Bothrops asper and Crotalus durissus cumanensis Venoms. Molecules 2022; 27:8588. [PMID: 36500682 PMCID: PMC9737558 DOI: 10.3390/molecules27238588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/02/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
Snakebite is a neglected tropical disease that causes extensive mortality and morbidity in rural communities. Antivenim sera are the currently approved therapy for snake bites; however, they have some therapeutic limitations that have been extensively documented. Recently, small molecule toxin inhibitors have received significant attention as potential alternatives or co-adjuvant to immunoglobulin-based snakebite therapies. Thus, in this study, we evaluated the inhibitory effects of the phospholipase A2 inhibitor varespladib and the metalloproteinase inhibitor CP471474 and their synergistic effects on the lethal, edema-forming, hemorrhagic, and myotoxic activities of Bothrops asper and Crotalus durissus cumanensis venoms from Colombia. Except for the preincubation assay of the lethal activity with B. asper venom, the mixture showed the best inhibitory activity. Nevertheless, the mix did not display statistically significant differences to varespladib and CP471474 used separately in all assays. In preincubation assays, varespladib showed the best inhibitory activity against the lethal effect induced by B. asper venom. However, in independent injection assays, the mix of the compounds partially inhibited the lethal activity of both venoms (50%). In addition, in the assays to test the inhibition of edema-forming activity, the mixture exhibited the best inhibitory activity, followed by Varespladib, but without statistically significant differences (p > 0.05). The combination also decreased the myotoxic activity of evaluated venoms. In these assays, the mix showed statistical differences regarding CP471474 (p < 0.05). The mixture also abolished the hemorrhagic activity of B. asper venom in preincubation assays, with no statistical differences to CP471474. Finally, the mixture showed inhibition in studies with independent administration in a time-dependent manner. To propose a mode of action of varespladib and CP471474, molecular docking was performed. PLA2s and SVMPs from tested venoms were used as targets. In all cases, our molecular modeling results suggested that inhibitors may occupy the substrate-binding cleft of the enzymes, which was supported by specific interaction with amino acids from the active site, such as His48 for PLA2s and Glu143 for the metalloproteinase. In addition, varespladib and CP471474 also showed interaction with residues from the hydrophobic channel in PLA2s and substrate binding subsites in the SVMP. Our results suggest a synergistic action of the mixed inhibitors and show the potential of varespladib, CP471474, and their mixture to generate new treatments for snakebite envenoming with application in the field or as antivenom co-adjuvants.
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Affiliation(s)
- Sara Quiroz
- Research Group in Toxinology, Pharmaceutical, and Food Alternatives, Pharmaceutical and Food Sciences Faculty, University of Antioquia, Medellín 50010, Colombia
| | - Isabel C. Henao Castañeda
- Research Group in Marine Natural Products, Pharmaceutical and Food Sciences Faculty, University of Antioquia, Medellín 050010, Colombia
| | - Johan Granados
- Research Group in Pharmaceutical Promotion and Prevention, Universidad de Antioquia, Medellín 050010, Colombia
| | - Arley Camilo Patiño
- Research Group in Toxinology, Pharmaceutical, and Food Alternatives, Pharmaceutical and Food Sciences Faculty, University of Antioquia, Medellín 50010, Colombia
| | - Lina María Preciado
- Research Group in Toxinology, Pharmaceutical, and Food Alternatives, Pharmaceutical and Food Sciences Faculty, University of Antioquia, Medellín 50010, Colombia
| | - Jaime Andrés Pereañez
- Research Group in Toxinology, Pharmaceutical, and Food Alternatives, Pharmaceutical and Food Sciences Faculty, University of Antioquia, Medellín 50010, Colombia
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Lewin MR, Carter RW, Matteo IA, Samuel SP, Rao S, Fry BG, Bickler PE. 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; 14:783. [PMID: 36422958 PMCID: PMC9695340 DOI: 10.3390/toxins14110783] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [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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Affiliation(s)
- Matthew R. Lewin
- Division of Research, Ophirex, Inc., Corte Madera, CA 94925, USA
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA
| | | | - Isabel A. Matteo
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA
| | | | - Sunita Rao
- Division of Research, Ophirex, Inc., Corte Madera, CA 94925, USA
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Philip E. Bickler
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA
- Department of Anesthesia and Perioperative Care, University of California San Francisco School of Medicine, San Francisco, CA 94143, USA
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de Souza J, Oliveira IC, Yoshida EH, Cantuaria NM, Cogo JC, Torres-Bonilla KA, Hyslop S, Silva Junior NJ, Floriano RS, Gutiérrez JM, Oshima-Franco Y. Effect of the phospholipase A2 inhibitor Varespladib, and its synergism with crotalic antivenom, on the neuromuscular blockade induced by Crotalus durissus terrificus venom (with and without crotamine) in mouse neuromuscular preparations. Toxicon 2022; 214:54-61. [DOI: 10.1016/j.toxicon.2022.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 10/18/2022]
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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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