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Salvador GHM, Cardoso FF, Lomonte B, Fontes MRM. Inhibitors and activators for myotoxic phospholipase A 2-like toxins from snake venoms - A structural overview. Biochimie 2024:S0300-9084(24)00175-5. [PMID: 39089640 DOI: 10.1016/j.biochi.2024.07.016] [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: 04/10/2024] [Revised: 06/27/2024] [Accepted: 07/29/2024] [Indexed: 08/04/2024]
Abstract
Snakebite envenomations result in acute and chronic physical and psychological health effects on their victims, leading to a substantial socio-economic burden in tropical and subtropical countries. Local necrosis is one of the serious effects caused by envenomation, primarily induced by snake venoms from the Viperidae family through the direct action of components collectively denominated as myotoxins, including the phopholipase A2-like (PLA2-like) toxins. Considering the limitations of antivenoms in preventing the rapid development of local tissue damage caused by envenomation, the use of small molecule therapeutics has been suggested as potential first-aid treatments or as adjuvants to antivenom therapy. In this review, we provide an overview of the structural interactions of molecules exhibiting inhibitory activity toward PLA2-like toxins. Additionally, we discuss the implications for the myotoxic mechanism of PLA2-like toxins and the molecules involved in their activation, highlighting key differences between activators and inhibitors. Finally, we integrate all these results to propose a classification of inhibitors into three different classes and five sub-classes. Taking into account the structural and affinity information, we compare the different inhibitors/ligands to gain a deeper understanding of the structural basis for the effective inhibition of PLA2-like toxins. By offering these insights, we aim to contribute to the search for new and efficient inhibitor molecules to complement and improve current therapy by conventional antivenoms.
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Affiliation(s)
- Guilherme H M Salvador
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu-SP, Brazil
| | - Fábio F Cardoso
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu-SP, Brazil
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Marcos R M 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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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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de Oliveira ALN, Lacerda MT, Ramos MJ, Fernandes PA. Viper Venom Phospholipase A2 Database: The Structural and Functional Anatomy of a Primary Toxin in Envenomation. Toxins (Basel) 2024; 16:71. [PMID: 38393149 PMCID: PMC10893444 DOI: 10.3390/toxins16020071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 01/04/2024] [Accepted: 01/13/2024] [Indexed: 02/25/2024] Open
Abstract
Viper venom phospholipase A2 enzymes (vvPLA2s) and phospholipase A2-like (PLA2-like) proteins are two of the principal toxins in viper venom that are responsible for the severe myotoxic and neurotoxic effects caused by snakebite envenoming, among other pathologies. As snakebite envenoming is the deadliest neglected tropical disease, a complete understanding of these proteins' properties and their mechanisms of action is urgently needed. Therefore, we created a database comprising information on the holo-form, cofactor-bound 3D structure of 217 vvPLA2 and PLA2-like proteins in their physiologic environment, as well as 79 membrane-bound viper species from 24 genera, which we have made available to the scientific community to accelerate the development of new anti-snakebite drugs. In addition, the analysis of the sequenced, 3D structure of the database proteins reveals essential aspects of the anatomy of the proteins, their toxicity mechanisms, and the conserved binding site areas that may anchor universal interspecific inhibitors. Moreover, it pinpoints hypotheses for the molecular origin of the myotoxicity of the PLA2-like proteins. Altogether, this study provides an understanding of the diversity of these toxins and how they are conserved, and it indicates how to develop broad, interspecies, efficient small-molecule inhibitors to target the toxin's many mechanisms of action.
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Affiliation(s)
| | | | | | - Pedro A. Fernandes
- Requimte-Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4169-000 Porto, Portugal; (A.L.N.d.O.); (M.T.L.); (M.J.R.)
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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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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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Luo P, Ji Y, Liu X, Zhang W, Cheng R, Zhang S, Qian X, Huang C. Affected inflammation-related signaling pathways in snake envenomation: A recent insight. Toxicon 2023; 234:107288. [PMID: 37703930 DOI: 10.1016/j.toxicon.2023.107288] [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: 07/23/2023] [Revised: 08/24/2023] [Accepted: 09/09/2023] [Indexed: 09/15/2023]
Abstract
Snake envenomation is well known to cause grievous pathological signs, including haemorrhagic discharge, necrosis, and respiratory distress. However, inflammatory reactions are also common envenoming manifestations that lead to successive damage, such as oedema, ulceration, lymphadenectasis, systemic inflammatory response syndrome (SIRS) and even multiple organ dysfunction syndrome (MODS). Interference with the inflammatory burst is hence important in the clinical treatment of snake envenomation. Here, we summarize the typical snake toxins (or venoms) that cause inflammatory reactions and the underlying signaling pathways. In brief, inflammatory reactions are usually triggered by snake venom phospholipase A2 (svPLA2), snake venom metalloprotease (SVMP), snake venom serine protease (SVSP) and C-type lectin/snaclec (CTL) as well as disintegrin (DIS) via multiple signaling pathways. They are nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3), nuclear factor kappa-B (NF-κB), mitogen-activated protein kinase (MAPK), janus kinase/signal transducer and activator of transcription (JAK-STAT) and phosphoinositide 3-Kinase/protein kinase B (PI3K/PKB also called PI3K-AKT) signaling pathways. Activation of these pathways promotes the expression of pro-inflammatory molecules such as cytokines, especially interleukin-1β (IL-1β) which causes further inflammatory cascades and manifestations, such as swelling, fever, pain, and severe complications. Remarkably, almost half of introduced snake toxins (or venoms) have anti-inflammatory effects through blocking these pathways and suppressing the expression of pro-inflammatory molecules. Investigation of affected inflammation-related signaling pathways is meaningful to achieve better clinical treatment.
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Affiliation(s)
- Peiyi Luo
- Queen Mary School, Nanchang University, Nanchang, Jiangxi, 330000, PR China.
| | - Yuxin Ji
- Queen Mary School, Nanchang University, Nanchang, Jiangxi, 330000, PR China.
| | - Xiaohan Liu
- Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, PR China.
| | - Weiyun Zhang
- Queen Mary School, Nanchang University, Nanchang, Jiangxi, 330000, PR China.
| | - Ruoxi Cheng
- Queen Mary School, Nanchang University, Nanchang, Jiangxi, 330000, PR China.
| | - Shuxian Zhang
- Queen Mary School, Nanchang University, Nanchang, Jiangxi, 330000, PR China.
| | - Xiao Qian
- Queen Mary School, Nanchang University, Nanchang, Jiangxi, 330000, PR China.
| | - Chunhong Huang
- College of Basic Medical Sciences, Nanchang University, Nanchang, Jiangxi, 330000, PR China.
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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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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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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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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:molecules27238588. [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] [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
- Correspondence: (L.M.P.); (J.A.P.)
| | - Jaime Andrés Pereañez
- Research Group in Toxinology, Pharmaceutical, and Food Alternatives, Pharmaceutical and Food Sciences Faculty, University of Antioquia, Medellín 50010, Colombia
- Correspondence: (L.M.P.); (J.A.P.)
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11
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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: 22] [Impact Index Per Article: 11.0] [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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12
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Laustsen A, Gless BH, Jenkins TP, Meyhoff-Madsen M, Bjärtun J, Munk AS, Oscoz S, Fernández J, Gutiérrez JM, Lomonte B, Lohse B. In Vivo Neutralization of Myotoxin II, a Phospholipase A 2 Homologue from Bothrops asper Venom, Using Peptides Discovered via Phage Display Technology. ACS OMEGA 2022; 7:15561-15569. [PMID: 35571794 PMCID: PMC9096979 DOI: 10.1021/acsomega.2c00280] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 03/15/2022] [Indexed: 06/15/2023]
Abstract
Many snake venom toxins cause local tissue damage in prey and victims, which constitutes an important pathology that is challenging to treat with existing antivenoms. One of the notorious toxins that causes such effects is myotoxin II present in the venom of the Central and Northern South American viper, Bothrops asper. This Lys49 PLA2 homologue is devoid of enzymatic activity and causes myotoxicity by disrupting the cell membranes of muscle tissue. To improve envenoming therapy, novel approaches are needed, warranting the discovery and development of inhibitors that target key toxins that are currently difficult to neutralize. Here, we report the identification of a new peptide (JB006), discovered using phage display technology, that is capable of binding to and neutralizing the toxic effects of myotoxin II in vitro and in vivo. Through computational modeling, we further identify hypothetical binding interactions between the toxin and the peptide to enable further development of inhibitors that can neutralize myotoxin II.
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Affiliation(s)
- Andreas
H. Laustsen
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, Lyngby DK-2800, Denmark
| | - Bengt H. Gless
- Department
of Drug Design and Pharmacology, University
of Copenhagen, Copenhagen DK-2100, Denmark
| | - Timothy P. Jenkins
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, Lyngby DK-2800, Denmark
| | - Maria Meyhoff-Madsen
- Department
of Drug Design and Pharmacology, University
of Copenhagen, Copenhagen DK-2100, Denmark
| | - Johanna Bjärtun
- Department
of Drug Design and Pharmacology, University
of Copenhagen, Copenhagen DK-2100, Denmark
| | - Andreas S. Munk
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, Lyngby DK-2800, Denmark
| | - Saioa Oscoz
- Department
of Biotechnology and Biomedicine, Technical
University of Denmark, Lyngby DK-2800, Denmark
| | - Julián Fernández
- Instituto
Clodomiro Picado, Faculty of Microbiology, University of Costa Rica, San
José 11501-2060, Costa Rica
| | - José María Gutiérrez
- Instituto
Clodomiro Picado, Faculty of Microbiology, University of Costa Rica, San
José 11501-2060, Costa Rica
| | - Bruno Lomonte
- Instituto
Clodomiro Picado, Faculty of Microbiology, University of Costa Rica, San
José 11501-2060, Costa Rica
| | - Brian Lohse
- Department
of Drug Design and Pharmacology, University
of Copenhagen, Copenhagen DK-2100, Denmark
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13
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Solving the microheterogeneity of Bothrops asper myotoxin-II by high-resolution mass spectrometry: Insights into C-terminal region variability in Lys49-phospholipase A2 homologs. Toxicon 2022; 210:123-131. [DOI: 10.1016/j.toxicon.2022.02.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 02/27/2022] [Accepted: 02/28/2022] [Indexed: 11/21/2022]
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14
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Varespladib (LY315920) rescued mice from fatal neurotoxicity caused by venoms of five major Asiatic kraits (Bungarus spp.) in an experimental envenoming and rescue model. Acta Trop 2022; 227:106289. [PMID: 34929179 DOI: 10.1016/j.actatropica.2021.106289] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/16/2021] [Accepted: 12/16/2021] [Indexed: 11/23/2022]
Abstract
The venoms of Asiatic kraits (Bungarus spp.) contain various neurotoxic phospholipases A2 (beta-bungarotoxins) which can irreversibly damage motor nerve terminals, resulting in rapidly fatal suffocation by respiratory muscle paralysis or oral airway obstruction. Hence, there is a need of adjunct therapy at the pre-hospital stage to prevent or delay the onset of neurotoxicity, so that antivenom can be given within golden hour before the envenoming becomes antivenom-resistant. This study investigated the efficacy of varespladib, a small molecule PLA2 (phospholipase A2) inhibitor, given as a bolus subcutaneously upon the onset of krait venom-induced paralysis in a mouse experimental envenoming and rescue model, where the severity of neurotoxicity was scored and the survival rate was monitored over 24 h. Varespladib at 10 mg/kg effectively alleviated the neurotoxicity of Bungarus sindanus, Bungarus multicinctus and Bungarus fasciatus venoms, and rescued all mice from venom-induced lethality (100% survival). Varespladib at this dose, however, only partially reduced the neurotoxicity of Bungarus caeruleus and Bungarus candidus venoms, while all challenged mice were dead by 23 h (B. caeruleus) and 12 h (B. candidus). An increased dose of varespladib at 20 mg/kg markedly abated the venom neurotoxicity past 8 h of envenoming, and protected the mice from venom lethality (B. caeruleus: 75% survival; B. candidus: 100% survival). The finding is consistent with previous studies which demonstrated varespladib's inhibitory effect against some snake venoms. The findings suggest varespladib could be repurposed as an emergency drug for prevention or rescue (if given early enough) from the acute, neurotoxic envenoming syndromes caused by various major krait species in Asia.
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15
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Gutierres PG, Pereira DR, Vieira NL, Arantes LF, Silva NJ, Torres-Bonilla KA, Hyslop S, Morais-Zani K, Nogueira RMB, Rowan EG, Floriano RS. Action of Varespladib (LY-315920), a Phospholipase A 2 Inhibitor, on the Enzymatic, Coagulant and Haemorrhagic Activities of Lachesis muta rhombeata (South-American Bushmaster) Venom. Front Pharmacol 2022; 12:812295. [PMID: 35095526 PMCID: PMC8790531 DOI: 10.3389/fphar.2021.812295] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/09/2021] [Indexed: 01/08/2023] Open
Abstract
Varespladib (VPL) was primarily developed to treat inflammatory disturbances associated with high levels of serum phospholipase A2 (PLA2). VPL has also demonstrated to be a potential antivenom support agent to prevent PLA2-dependent effects produced by snake venoms. In this study, we examined the action of VPL on the coagulant, haemorrhagic and enzymatic activities of Lachesis muta rhombeata (South-American bushmaster) venom. Conventional colorimetric enzymatic assays were performed for PLA2, caseinolytic and esterasic activities; in vitro coagulant activities for prothrombin time (PT) and activated partial thromboplastin time (aPTT) were performed in rat citrated plasma through a quick timer coagulometer, whereas the dimensions of haemorrhagic haloes obtained after i.d. injections of venom in Wistar rats were determined using ImageJ software. Venom (1 mg/ml) exhibited accentuated enzymatic activities for proteases and PLA2in vitro, with VPL abolishing the PLA2 activity from 0.01 mM; VPL did not affect caseinolytic and esterasic activities at any tested concentrations (0.001–1 mM). In rat citrated plasma in vitro, VPL (1 mM) alone efficiently prevented the venom (1 mg/ml)-induced procoagulant disorder associated to extrinsic (PT) pathway, whereas its association with a commercial antivenom successfully prevented changes in both intrinsic (aPTT) and extrinsic (PT) pathways; commercial antivenom by itself failed to avoid the procoagulant disorders by this venom. Venom (0.5 mg/kg)-induced hemorrhagic activity was slightly reduced by VPL (1 mM) alone or combined with antivenom (antivenom:venom ratio 1:3 ‘v/w’) in rats, with antivenom alone producing no protective action on this parameter. In conclusion, VPL does not inhibit other major enzymatic groups of L. m. rhombeata venom, with its high PLA2 antagonize activity efficaciously preventing the venom-induced coagulation disturbances.
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Affiliation(s)
- Pamella G Gutierres
- Laboratory of Toxinology and Cardiovascular Research, University of Western São Paulo, Presidente Prudente, Brazil
| | - Diego R Pereira
- Laboratory of Toxinology and Cardiovascular Research, University of Western São Paulo, Presidente Prudente, Brazil
| | - Nataly L Vieira
- Laboratory of Toxinology and Cardiovascular Research, University of Western São Paulo, Presidente Prudente, Brazil
| | - Lilian F Arantes
- Graduate Program in Zootechnics, Rural Federal University of Pernambuco, Recife, Brazil
| | - Nelson J Silva
- Graduate Program in Environmental Sciences and Health, School of Medical, Pharmaceutical and Biomedical Sciences, Pontifical Catholic University of Goiás, Goiânia, Brazil
| | - Kristian A Torres-Bonilla
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, Brazil
| | - Stephen Hyslop
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, Brazil
| | | | - Rosa M B Nogueira
- Laboratory of Toxinology and Cardiovascular Research, University of Western São Paulo, Presidente Prudente, Brazil
| | - Edward G Rowan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Rafael S Floriano
- Laboratory of Toxinology and Cardiovascular Research, University of Western São Paulo, Presidente Prudente, Brazil
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16
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Borges RJ, Salvador GHM, Pimenta DC, Dos Santos LD, Fontes MRM, Usón I. SEQUENCE SLIDER: integration of structural and genetic data to characterize isoforms from natural sources. Nucleic Acids Res 2022; 50:e50. [PMID: 35104880 PMCID: PMC9122596 DOI: 10.1093/nar/gkac029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 01/05/2022] [Accepted: 01/30/2022] [Indexed: 12/28/2022] Open
Abstract
Proteins isolated from natural sources can be composed of a mixture of isoforms with similar physicochemical properties that coexist in the final steps of purification. Yet, even where unverified, the assumed sequence is enforced throughout the structural studies. Herein, we propose a novel perspective to address the usually neglected sequence heterogeneity of natural products by integrating biophysical, genetic and structural data in our program SEQUENCE SLIDER. The aim is to assess the evidence supporting chemical composition in structure determination. Locally, we interrogate the experimental map to establish which side chains are supported by the structural data, and the genetic information relating sequence conservation is integrated into this statistic. Hence, we build a constrained peptide database, containing most probable sequences to interpret mass spectrometry data (MS). In parallel, we perform MS de novo sequencing with genomic-based algorithms to detect point mutations. We calibrated SLIDER with Gallus gallus lysozyme, whose sequence is unequivocally established and numerous natural isoforms are reported. We used SLIDER to characterize a metalloproteinase and a phospholipase A2-like protein from the venom of Bothrops moojeni and a crotoxin from Crotalus durissus collilineatus. This integrated approach offers a more realistic structural descriptor to characterize macromolecules isolated from natural sources.
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Affiliation(s)
- Rafael J Borges
- Departament of Biophysics and Pharmacology, Biosciences Institute, São Paulo State University (UNESP), Botucatu, São Paulo 18618-689, Brazil.,Crystallographic Methods, Institute of Molecular Biology of Barcelona (IBMB-CSIC), Barcelona 08028, Spain
| | - Guilherme H M Salvador
- Departament of Biophysics and Pharmacology, Biosciences Institute, São Paulo State University (UNESP), Botucatu, São Paulo 18618-689, Brazil
| | - Daniel C Pimenta
- Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, São Paulo 05503-900, Brazil
| | - Lucilene D Dos Santos
- Graduate Program in Tropical Diseases, Botucatu Medical School (FMB), São Paulo State University (UNESP), Botucatu, São Paulo 18618-687, Brazil.,Biotechnology Institute (IBTEC), São Paulo State University (UNESP), Botucatu, São Paulo 18607-440, Brazil
| | - Marcos R M Fontes
- Departament of Biophysics and Pharmacology, Biosciences Institute, São Paulo State University (UNESP), Botucatu, São Paulo 18618-689, Brazil
| | - Isabel Usón
- Crystallographic Methods, Institute of Molecular Biology of Barcelona (IBMB-CSIC), Barcelona 08028, Spain.,ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
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17
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BthTX-II from Bothrops jararacussu venom has variants with different oligomeric assemblies: An example of snake venom phospholipases A 2 versatility. Int J Biol Macromol 2021; 191:255-266. [PMID: 34547312 DOI: 10.1016/j.ijbiomac.2021.09.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 10/20/2022]
Abstract
Phospholipases A2 (PLA2s) are found in almost every venomous snake family. In snakebites, some PLA2s can quickly cause local myonecrosis, which may lead to permanent sequelae if antivenom is administered belatedly. They hydrolyse phospholipids in membranes through a catalytic calcium ions-dependent mechanism. BthTX-II is a basic PLA2 and the second major component in the venom of Bothrops jararacussu. Herein, using the software SEQUENCE SLIDER, which integrates crystallographic, mass spectrometry and genetic data, we characterized the primary, tertiary and quaternary structure of two BthTX-II variants (called a and b), which diverge in 7 residues. Crystallographic structure BthTX-IIa is in a Tense-state with its distorted calcium binding loop buried in the dimer interface, contrarily, the novel BthTX-IIb structure is a monomer in a Relax-state with a fatty acid in the hydrophobic channel. Structural data in solution reveals that both variants are monomeric in neutral physiological conditions and mostly dimeric in an acidic environment, being catalytic active in both situations. Therefore, we propose two myotoxic mechanisms for BthTX-II, a catalytic one associated with the monomeric assembly, whereas the other has a calcium independent activity related to its C-terminal region, adopting a dimeric conformation similar to PLA2-like proteins.
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18
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Maciel FV, Ramos Pinto ÊK, Valério Souza NM, Gonçalves de Abreu TA, Ortolani PL, Fortes-Dias CL, Garrido Cavalcante WL. Varespladib (LY315920) prevents neuromuscular blockage and myotoxicity induced by crotoxin on mouse neuromuscular preparations. Toxicon 2021; 202:40-45. [PMID: 34562493 DOI: 10.1016/j.toxicon.2021.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/15/2021] [Accepted: 09/20/2021] [Indexed: 12/26/2022]
Abstract
Varespladib (LY315920) is a synthetic phospholipase A2 (PLA2) inhibitor that has been demonstrating antiophidic potential against snake venoms that present PLA2 neurotoxins. In this study, we evaluate the capacity of Varespladib to inhibit the neuromuscular effects of crotoxin (CTX), the main toxic component of Crotalus durissus terrificus snake venom, and its PLA2 subunit (CB). We performed a myographic study to compare the neuromuscular effects of CTX or CB and the mixture of these substances plus Varespladib in mice phrenic nerve-diaphragm muscle preparations. CTX (5 μg/mL), CB (20 μg/mL), or toxin-inhibitor mixtures pre-incubated with different concentration ratios of Varespladib (1:0.25; 1:0.5; 1:1; w/w) were added to the preparations and maintained throughout the experimentation period. Myotoxicity was assessed by light microscopic analysis of diaphragm muscle after myographic study. CTX and CB blocked the nerve-evoked twitches, and only CTX induced histological alterations in diaphragm muscle. Pre-incubation with Varespladib abolished the muscle-paralyzing activity of CTX and CB, and also the muscle-damaging activity of CTX. These findings emphasize the clinical potential of Varespladib in mitigating the toxic effects of C. d. terrificus snakebites and as a research tool to advance the knowledge of the mechanism of action of snake toxins.
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Affiliation(s)
- Fernanda Valadares Maciel
- Department of Pharmacology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Brazil
| | - Êmylle Karoline Ramos Pinto
- Department of Pharmacology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Brazil
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19
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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: 12] [Impact Index Per Article: 4.0] [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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