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Salvador GHM, Cardoso FF, Gomes AA, Cavalcante WLG, Gallacci M, Fontes MRM. Search for efficient inhibitors of myotoxic activity induced by ophidian phospholipase A 2-like proteins using functional, structural and bioinformatics approaches. Sci Rep 2019; 9:510. [PMID: 30679550 PMCID: PMC6346006 DOI: 10.1038/s41598-018-36839-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 11/29/2018] [Indexed: 02/01/2023] Open
Abstract
Ophidian accidents are considered an important neglected tropical disease by the World Health Organization. Particularly in Latin America, Bothrops snakes are responsible for the majority of the snakebite envenomings that are not efficiently treated by conventional serum therapy. Thus, the search for simple and efficient inhibitors to complement this therapy is a promising research area, and a combination of functional and structural assays have been used to test candidate ligands against specific ophidian venom compounds. Herein, we tested a commercial drug (acetylsalicylic acid, ASA) and a plant compound with antiophidian properties (rosmarinic acid, RA) using myographic, crystallographic and bioinformatics experiments with a phospholipase A2-like toxin, MjTX-II. MjTX-II/RA and MjTX-II/ASA crystal structures were solved at high resolution and revealed the presence of ligands bound to different regions of the toxin. However, in vitro myographic assays showed that only RA is able to prevent the myotoxic effects of MjTX-II. In agreement with functional results, molecular dynamics simulations showed that the RA molecule remains tightly bound to the toxin throughout the calculations, whereas ASA molecules tend to dissociate. This approach aids the design of effective inhibitors of PLA2-like toxins and, eventually, may complement serum therapy.
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Affiliation(s)
- Guilherme H M Salvador
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Fábio Florença Cardoso
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Antoniel A Gomes
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Walter L G Cavalcante
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
- Depto. de Farmacologia, UFMG - Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Márcia Gallacci
- Depto. de Farmacologia, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - Marcos R M Fontes
- Depto. de Física e Biofísica, Instituto de Biociências, UNESP - Universidade Estadual Paulista, Botucatu, SP, Brazil.
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Oliveira ICF, de Paula MO, Lastra HCB, Alves BDB, Moreno DAN, Yoshida EH, Amaral Filho J, Cogo JC, Varanda EA, Rai M, Santos CAD, Oshima-Franco Y. Activity of silver nanoparticles on prokaryotic cells and Bothrops jararacussu snake venom. Drug Chem Toxicol 2018; 42:60-64. [PMID: 29961355 DOI: 10.1080/01480545.2018.1478850] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Nanoparticle-conjugated venom-toxins of venomous animals and its therapeutic efficacy against emerging or neglecting diseases is a promising strategy. In this study, silver nanoparticles (AgNPs ∼50 nm, 0.081 mg mL-1) were studied against the neuromuscular blockade, myotoxic effects induced by Bothrops jararacussu venom (60 µg mL-1) and also against prokaryotic cells. The neurotoxicity was evaluated on ex vivo mouse phrenic nerve-diaphragm using traditional myographic technique, able to obtain functional contractile responses and to check the neurotransmission. The myotoxicity on mammalian cells was evaluated in muscles resulting from pharmacological assays using routine histological techniques and light microscopy. The toxicity to prokaryotic cells was evaluated on Salmonella typhimurium TA100 without metabolic activation. The in vitro preincubation model between AgNPs and venom was enough to abolish toxic effects of B. jararacussu venom, but mammalian cells were highly sensitive to AgNPs more than prokaryotic cells, by acting as dose-independently and dose-dependently parameters, respectively. These results allowed us to conclude that AgNPs showed promising activity as antivenom agent but for its safer use, the toxicity should be evaluated on experimental animals.
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Affiliation(s)
| | | | | | - Bruno de Brito Alves
- c Post-Graduate Program in Pharmaceutical Sciences , University of Sorocaba (UNISO) , Sorocaba , Brazil
| | | | - Edson Hideaki Yoshida
- c Post-Graduate Program in Pharmaceutical Sciences , University of Sorocaba (UNISO) , Sorocaba , Brazil
| | - Jorge Amaral Filho
- c Post-Graduate Program in Pharmaceutical Sciences , University of Sorocaba (UNISO) , Sorocaba , Brazil
| | - José Carlos Cogo
- d Bioengineering and Biomedical Engineering Programs, Technological and Scientific Institute , Brazil University , Itaquera, São Paulo , Brazil
| | - Eliana Aparecida Varanda
- e Pharmaceutical Sciences Faculty of Araraquara , São Paulo State University (UNESP) , Araraquara , Brazil
| | - Mahendra Rai
- f Department of Biotechnology , SGB Amravati University , Amravati , India
| | - Carolina Alves Dos Santos
- c Post-Graduate Program in Pharmaceutical Sciences , University of Sorocaba (UNISO) , Sorocaba , Brazil
| | - Yoko Oshima-Franco
- c Post-Graduate Program in Pharmaceutical Sciences , University of Sorocaba (UNISO) , Sorocaba , Brazil
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Harder C, de Oliveira AL, Scriboni AB, Cintra ACO, Schezaro-Ramos R, Dos Santos MG, Cogo-Müller K, Miura RYH, Floriano RS, Rostelato-Ferreira S, Oshima-Franco Y. Pharmacological Properties of Vochysia Haenkeana (Vochysiaceae) Extract to Neutralize the Neuromuscular Blockade Induced by Bothropstoxin-I (Lys49 Phospholipase A 2) Myotoxin. Adv Pharm Bull 2017; 7:433-439. [PMID: 29071226 PMCID: PMC5651065 DOI: 10.15171/apb.2017.052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 08/10/2017] [Accepted: 08/15/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose: Bothrops snakes are responsible for more than 70 % of snakebites every year in Brazil and their venoms cause severe local and systemic damages. The pharmacological properties of medicinal plants have been widely investigated in order to discover new alternative treatments for different classes of diseases including neglected tropical diseases as envenomation by snakebites. In this work, we have investigated the ability of Vochysia haenkeana stem barks extract (VhE) to neutralize the neuromuscular effects caused by Bothropstoxin-I (BthTX-I), the major phospholipase A2 (PLA2) myotoxin from B. jararacussu venom. Methods: The biological compounds of VhE were analysed under thin layer chromatography (TLC) and its neutralizing ability against BthTX-I was assessed through twitch-tension recordings and histological analysis in mouse phrenic nerve-diaphragm (PND) preparations. The antimicrobial activity of VhE was assessed against S. aureus, E. coli and P. aeruginosa strains. The aggregation activity of VhE was analysed under protein precipitation assay. Results: VhE showed the presence of phenolic compound visualized by blue trace under TLC. VhE abolished the neuromuscular blockade caused by BthTX-I applying the pre-toxin incubation treatment and partially neutralized the BthTX-I action under post-toxin incubation treatment; VhE contributed slightly to decrease the myotoxicity induced by BthTX-I. The neutralizing mechanism of VhE may be related to protein aggregation. VhE showed no antimicrobial activity. Conclusion: V. haenkeana extract which has no antimicrobial activity exhibited neutralizing ability against the neuromuscular blockade caused by BthTX-I and also contributed to decrease its myotoxicity. Protein aggregation involving phenolic compounds may be related in these protective effects.
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Affiliation(s)
- Carolina Harder
- Institute of Health Sciences, Universidade Paulista (Unip), Av. Independência 210, 18087-100, Sorocaba, SP, Brazil
| | - Akila Lara de Oliveira
- University of Sorocaba (Uniso), Rodovia Raposo Tavares km 92.5, 18023-000, Sorocaba, SP, Brazil
| | - Andreia Borges Scriboni
- Department of Pharmacology, Piracicaba Dental School, State University of Campinas (UNICAMP), Av. Limeira 901, 13414-903, Piracicaba, SP, Brazil
| | - Adélia Cristina Oliveira Cintra
- Faculty of Pharmaceutical Sciences, Department of Clinical and Toxicological Analysis and Bromatology, São Paulo University (USP), Via do Café S/N, 14040-903, Ribeirão Preto, SP, Brazil
| | - Raphael Schezaro-Ramos
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo 126, 13083-887, Campinas, SP, Brazil
| | | | - Karina Cogo-Müller
- Faculty of Pharmaceutical Sciences, State University of Campinas (UNICAMP), Rua Cândido Portinari, 200, 13083-871, Campinas, SP, Brazil
| | - Regina Yuri Hashimoto Miura
- Institute of Health Sciences, Universidade Paulista (Unip), Av. Independência 210, 18087-100, Sorocaba, SP, Brazil
| | - Rafael Stuani Floriano
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo 126, 13083-887, Campinas, SP, Brazil
| | - Sandro Rostelato-Ferreira
- Institute of Health Sciences, Universidade Paulista (Unip), Av. Independência 210, 18087-100, Sorocaba, SP, Brazil
| | - Yoko Oshima-Franco
- University of Sorocaba (Uniso), Rodovia Raposo Tavares km 92.5, 18023-000, Sorocaba, SP, Brazil
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Influence of phospholipasic inhibition on neuromuscular activity of Bothrops fonsecai snake venom. Toxicon 2017; 130:35-43. [DOI: 10.1016/j.toxicon.2017.02.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 02/23/2017] [Accepted: 02/24/2017] [Indexed: 11/20/2022]
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Pattern of cardiotoxin-induced muscle remodeling in distinct TLR-4 deficient mouse strains. Histochem Cell Biol 2017; 148:49-60. [DOI: 10.1007/s00418-017-1556-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2017] [Indexed: 01/04/2023]
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Functional and structural studies of a Phospholipase A2-like protein complexed to zinc ions: Insights on its myotoxicity and inhibition mechanism. Biochim Biophys Acta Gen Subj 2017; 1861:3199-3209. [DOI: 10.1016/j.bbagen.2016.08.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/05/2016] [Accepted: 08/10/2016] [Indexed: 12/28/2022]
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Collaço RDCO, Randazzo-Moura P, Tamascia ML, da Silva IRF, Rocha T, Cogo JC, Hyslop S, Sanny CG, Rodrigues-Simioni L. Bothrops fonsecai snake venom activities and cross-reactivity with commercial bothropic venom. Comp Biochem Physiol C Toxicol Pharmacol 2017; 191:86-100. [PMID: 27590117 DOI: 10.1016/j.cbpc.2016.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 07/05/2016] [Accepted: 08/26/2016] [Indexed: 10/21/2022]
Abstract
In this work, we examined some biochemical and biological activities of Bothrops fonsecai venom, a pitviper endemic to southeastern Brazil, and assessed their neutralization by commercial bothropic antivenom (CAv). Cross-reactivity of venom with CAv was also assessed by immunoblotting and size-exclusion high performance chromatography (SE-HPLC). Bothrops fonsecai venom had PLA2, proteolytic and esterase activities that were neutralized to varying extents by venom:antivenom ratios of 5:1 and 5:2 (PLA2 and esterase activities) or not significantly by either venom:antivenom ratio (proteolytic activity). The minimum hemorrhagic dose (69.2μg) was totally neutralized by both ratios. Clotting time in rat citrated plasma was 33±10.5s (mean±SD; n=5) and was completely neutralized by a 5:2 ratio. Edema formation was dose-dependent (1-30μg/site) and significantly inhibited by both ratios. Venom (10-300μg/mL) caused neuromuscular blockade in extensor digitorum longus preparations; this blockade was inhibited best by a 5:2 ratio. Venom caused myonecrosis and creatine kinase release in vivo (gastrocnemius muscle) and in vitro (extensor digitorum longus) that was effectively neutralized by both venom:antivenom ratios. Immunoblotting showed that venom components of ~25-100kDa interacted with CAv. SE-HPLC profiles for venom incubated with CAv or specific anti-B. fonsecai antivenom raised in rabbits (SAv) indicated that CAv had a higher binding capacity than SAv, whereas SAv had higher affinity than CAv. These findings indicate that B. fonsecai venom contains various activities that are neutralized to different extents by CAv and suggest that CAv could be used to treat envenoming by B. fonsecai.
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Affiliation(s)
- Rita de Cássia O Collaço
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
| | - Priscila Randazzo-Moura
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil; Laboratório de Farmacologia, Faculdade de Ciências Médicas e da Saúde, Pontífica Universidade Católica de São Paulo (PUCSP), Praça Dr. José Ermirio de Moraes, 290, 18030-095, Sorocaba, SP, Brazil.
| | - Mariana L Tamascia
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
| | - Igor Rapp F da Silva
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
| | - Thalita Rocha
- Laboratório Multidisciplinar de Pesquisa, Universidade São Francisco (USF), Avenida São Francisco de Assis, 281, Jardim São José, 12916-900, Bragança Paulista, SP, Brazil
| | - José C Cogo
- Serpentário do Centro de Estudos da Natureza, Universidade do Vale do Paraíba (UNIVAP), Avenida Shishima Hifumi, 2911, Urbanova, 12244-000, São José dos Campos, SP, Brazil
| | - Stephen Hyslop
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
| | - Charles G Sanny
- Department of Biochemistry and Microbiology, Center for Health Sciences, Oklahoma State University (OSU), 1111 W. 17th Street, 74107, Tulsa, OK, USA
| | - Léa Rodrigues-Simioni
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887, Campinas, SP, Brazil
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Melaré R, Floriano RS, Gracia M, Rodrigues-Simioni L, Cruz-Höfling MAD, Rocha T. Ultrastructural aspects of mouse nerve-muscle preparation exposed to Bothrops jararacussu and Bothrops bilineatus venoms and their toxins BthTX-I and Bbil-TX: Unknown myotoxic effects. Microsc Res Tech 2016; 79:1082-1089. [PMID: 27535875 DOI: 10.1002/jemt.22748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 07/18/2016] [Accepted: 08/02/2016] [Indexed: 11/10/2022]
Abstract
Bites by Bothrops snakes normally induce local pain, haemorrhage, oedema and myonecrosis. Mammalian isolated nerve-muscle preparations exposed to Bothrops venoms and their phospholipase A2 toxins (PLA2 ) can exhibit a neurotoxic pattern as increase in frequency of miniature end-plate potentials (MEPPs) as well as in amplitude of end-plate potentials (EPPs); neuromuscular facilitation followed by complete and irreversible blockade without morphological evidence for muscle damage. In this work, we analysed the ultrastructural damage induced by Bothrops jararacussu and Bothrops bilineatus venoms and their PLA2 toxins (BthTX-I and Bbil-TX) in mouse isolated nerve-phrenic diaphragm preparations (PND). Under transmission electron microscopy (TEM), PND preparations previously exposed to B. jararacussu and B. bilineatus venoms and BthTX-I and Bbil-TX toxins showed hypercontracted and loosed myofilaments; unorganized sarcomeres; clusters of edematous sarcoplasmic reticulum and mitochondria; abnormal chromatin distribution or apoptotic-like nuclei. The principal affected organelles, mitochondria and sarcoplasmic reticulum, were those related to calcium buffering and, resulting in sarcomeres and myofilaments hypercontraction. Schwann cells were also damaged showing edematous axons and mitochondria as well as myelin sheath alteration. These ultrastructural changes caused by both of Bothrops venoms and toxins indicate that the neuromuscular blockade induced by them in vitro can also be associated with nerve and muscle degeneration.
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Affiliation(s)
- Rodolfo Melaré
- Multidisciplinary Research Laboratory, São Francisco University (USF), Av. São Francisco de Assis, 218, Zip Code 12916-900, Bragança Paulista, SP, Brazil
| | - Rafael Stuani Floriano
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, Zip Code 13083-887, Campinas, SP, Brazil
| | - Marta Gracia
- Multidisciplinary Research Laboratory, São Francisco University (USF), Av. São Francisco de Assis, 218, Zip Code 12916-900, Bragança Paulista, SP, Brazil
| | - Léa Rodrigues-Simioni
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, Zip Code 13083-887, Campinas, SP, Brazil
| | - Maria Alice da Cruz-Höfling
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Zip Code 13083-862, Campinas, SP, Brazil
| | - Thalita Rocha
- Multidisciplinary Research Laboratory, São Francisco University (USF), Av. São Francisco de Assis, 218, Zip Code 12916-900, Bragança Paulista, SP, Brazil. .,Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Rua Monteiro Lobato, 255, Zip Code 13083-862, Campinas, SP, Brazil.
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Presynaptic Proteins as Markers of the Neurotoxic Activity of BmjeTX-I and BmjeTX-II Toxins from Bothrops marajoensis (Marajó Lancehead) Snake Venom. Biochem Res Int 2016; 2016:2053459. [PMID: 27635261 PMCID: PMC5007310 DOI: 10.1155/2016/2053459] [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: 11/13/2015] [Revised: 06/02/2016] [Accepted: 07/03/2016] [Indexed: 11/18/2022] Open
Abstract
Neuromuscular preparations exposed to B. marajoensis venom show increases in the frequency of miniature end-plate potentials and twitch tension facilitation followed by presynaptic neuromuscular paralysis, without evidences of muscle damage. Considering that presynaptic toxins interfere into the machinery involved in neurotransmitter release (synaptophysin, synaptobrevin, and SNAP25 proteins), the main objective of this communication is to analyze, by immunofluorescence and western blotting, the expression of the synaptic proteins, synaptophysin, synaptobrevin, and SNAP25 and by myography, light, and transmission electron microscopy the pathology of motor nerve terminals and skeletal muscle fibres of chick biventer cervicis preparations (CBC) exposed in vitro to BmjeTX-I and BmjeTX-II toxins from B. marajoensis venom. CBC incubated with toxins showed irreversible twitch tension blockade and unaffected KCl- and ACh-evoked contractures, and the positive colabelling of acetylcholine receptors confirmed that their action was primarily at the motor nerve terminal. Hypercontraction and loose myofilaments and synaptic vesicle depletion and motor nerve damage indicated that the toxins displayed both myotoxic and neurotoxic effect. The blockade resulted from interference on synaptophysin, synaptobrevin, and SNAP25 proteins leading to the conclusion that BmjeTX-I and BmjeTX-II affected neurotransmitter release machinery by preventing the docking of synaptic vesicles to the axolemma of the nerve terminal.
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Ferraz MC, de Oliveira JL, de Oliveira Junior JR, Cogo JC, dos Santos MG, Franco LM, Puebla P, Ferraz HO, Ferraz HG, da Rocha MMT, Hyslop S, San Feliciano A, Oshima-Franco Y. The Triterpenoid Betulin Protects against the Neuromuscular Effects of Bothrops jararacussu Snake Venom In Vivo. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2015; 2015:939523. [PMID: 26633987 PMCID: PMC4655057 DOI: 10.1155/2015/939523] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 09/11/2015] [Accepted: 09/15/2015] [Indexed: 11/17/2022]
Abstract
We confirmed the ability of the triterpenoid betulin to protect against neurotoxicity caused by Bothrops jararacussu snake venom in vitro in mouse isolated phrenic nerve-diaphragm (PND) preparations and examined its capability of in vivo protection using the rat external popliteal/sciatic nerve-tibialis anterior (EPSTA) preparation. Venom caused complete, irreversible blockade in PND (40 μg/mL), but only partial blockade (~30%) in EPSTA (3.6 mg/kg, i.m.) after 120 min. In PND, preincubation of venom with commercial bothropic antivenom (CBA) attenuated the venom-induced blockade, and, in EPSTA, CBA given i.v. 15 min after venom also attenuated the blockade (by ~70% in both preparations). Preincubation of venom with betulin (200 μg/mL) markedly attenuated the venom-induced blockade in PND; similarly, a single dose of betulin (20 mg, i.p., 15 min after venom) virtually abolished the venom-induced decrease in contractility. Plasma creatine kinase activity was significantly elevated 120 min after venom injection in the EPSTA but was attenuated by CBA and betulin. These results indicate that betulin given i.p. has a similar efficacy as CBA given i.v. in attenuating the neuromuscular effects of B. jararacussu venom in vivo and could be a useful complementary measure to antivenom therapy for treating snakebite.
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Affiliation(s)
- Miriéle Cristina Ferraz
- Post-Graduate Program in Pharmaceutical Sciences and Pharmacy Course, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92,5, 18023-000 Sorocaba, SP, Brazil
| | - Jhones Luiz de Oliveira
- Post-Graduate Program in Pharmaceutical Sciences and Pharmacy Course, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92,5, 18023-000 Sorocaba, SP, Brazil
| | - Joel Reis de Oliveira Junior
- Post-Graduate Program in Pharmaceutical Sciences and Pharmacy Course, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92,5, 18023-000 Sorocaba, SP, Brazil
| | - José Carlos Cogo
- Serpentarium of the Center for Nature Studies and Institute for Research and Development (IP&D), Vale do Paraíba University (UNIVAP), Avenida Shishima Hifumi 291, 12244-000 São José dos Campos, SP, Brazil
| | - Márcio Galdino dos Santos
- Post-Graduate Program in Environmental Sciences, Tocantins Federal University, Avenida NS15, ALC NO14, 109 Norte, 77001-090 Palmas, TO, Brazil
| | - Luiz Madaleno Franco
- Pharmacy Course, Methodist University of Piracicaba (UNIMEP), Rodovia do Açúcar, Km 156, 13423-170 Piracicaba, SP, Brazil
| | - Pilar Puebla
- Department of Pharmaceutical Chemistry, Salamanca University, Campus “Miguel de Unamuno”, 37007 Salamanca, Spain
| | - Helena Onishi Ferraz
- Pharmacy Course, Federal University of São Paulo (UNIFESP), Rua Prof. Artur Riedel 275, 09972-270 Diadema, SP, Brazil
| | - Humberto Gomes Ferraz
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of São Paulo (USP), Avenida Prof. Lineu Prestes 580, 05434-070 São Paulo, SP, Brazil
| | | | - Stephen Hyslop
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo 126, Cidade Universitária Zeferino Vaz, 13083-870 Campinas, SP, Brazil
| | - Arturo San Feliciano
- Department of Pharmaceutical Chemistry, Salamanca University, Campus “Miguel de Unamuno”, 37007 Salamanca, Spain
| | - Yoko Oshima-Franco
- Post-Graduate Program in Pharmaceutical Sciences and Pharmacy Course, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92,5, 18023-000 Sorocaba, SP, Brazil
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Salvador GHM, Dreyer TR, Cavalcante WLG, Matioli FF, dos Santos JI, Velazquez-Campoy A, Gallacci M, Fontes MRM. Structural and functional evidence for membrane docking and disruption sites on phospholipase A2-like proteins revealed by complexation with the inhibitor suramin. ACTA ACUST UNITED AC 2015; 71:2066-78. [DOI: 10.1107/s1399004715014443] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 07/31/2015] [Indexed: 11/10/2022]
Abstract
Local myonecrosis resulting from snakebite envenomation is not efficiently neutralized by regular antivenom administration. This limitation is considered to be a significant health problem by the World Health Organization. Phospholipase A2-like (PLA2-like) proteins are among the most important proteins related to the muscle damage resulting from several snake venoms. However, despite their conserved tertiary structure compared with PLA2s, their biological mechanism remains incompletely understood. Different oligomeric conformations and binding sites have been identified or proposed, leading to contradictory data in the literature. In the last few years, a comprehensive hypothesis has been proposed based on fatty-acid binding, allosteric changes and the presence of two different interaction sites. In the present study, a combination of techniques were used to fully understand the structural–functional characteristics of the interaction between suramin and MjTX-II (a PLA2-like toxin).In vitroneuromuscular studies were performed to characterize the biological effects of the protein–ligand interaction and demonstrated that suramin neutralizes the myotoxic activity of MjTX-II. The high-resolution structure of the complex identified the toxin–ligand interaction sites. Calorimetric assays showed two different binding events between the protein and the inhibitor. It is demonstrated for the first time that the inhibitor binds to the surface of the toxin, obstructing the sites involved in membrane docking and disruption according to the proposed myotoxic mechanism. Furthermore, higher-order oligomeric formation by interaction with interfacial suramins was observed, which may also aid the inhibitory process. These results further substantiate the current myotoxic mechanism and shed light on the search for efficient inhibitors of the local myonecrosis phenomenon.
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Gonçalves-Machado L, Pla D, Sanz L, Jorge RJB, Leitão-De-Araújo M, Alves MLM, Alvares DJ, De Miranda J, Nowatzki J, de Morais-Zani K, Fernandes W, Tanaka-Azevedo AM, Fernández J, Zingali RB, Gutiérrez JM, Corrêa-Netto C, Calvete JJ. Combined venomics, venom gland transcriptomics, bioactivities, and antivenomics of two Bothrops jararaca populations from geographic isolated regions within the Brazilian Atlantic rainforest. J Proteomics 2015; 135:73-89. [PMID: 25968638 DOI: 10.1016/j.jprot.2015.04.029] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 04/21/2015] [Accepted: 04/28/2015] [Indexed: 12/20/2022]
Abstract
Bothrops jararaca is a slender and semi-arboreal medically relevant pit viper species endemic to tropical and subtropical forests in southern Brazil, Paraguay, and northern Argentina (Misiones). Within its geographic range, it is often abundant and is an important cause of snakebite. Although no subspecies are currently recognized, geographic analyses have revealed the existence of two well-supported B. jararaca clades that diverged during the Pliocene ~3.8Mya and currently display a southeastern (SE) and a southern (S) Atlantic rainforest (Mata Atlântica) distribution. The spectrum, geographic variability, and ontogenetic changes of the venom proteomes of snakes from these two B. jararaca phylogroups were investigated applying a combined venom gland transcriptomic and venomic analysis. Comparisons of the venom proteomes and transcriptomes of B. jararaca from the SE and S geographic regions revealed notable interpopulational variability that may be due to the different levels of population-specific transcriptional regulation, including, in the case of the southern population, a marked ontogenetic venom compositional change involving the upregulation of the myotoxic PLA2 homolog, bothropstoxin-I. This population-specific marker can be used to estimate the proportion of venom from the southern population present in the B. jararaca venom pool used for the Brazilian soro antibotrópico (SAB) antivenom production. On the other hand, the southeastern population-specific D49-PLA2 molecules, BinTX-I and BinTX-II, lend support to the notion that the mainland ancestor of Bothrops insularis was originated within the same population that gave rise to the current SE B. jararaca phylogroup, and that this insular species endemic to Queimada Grande Island (Brazil) expresses a pedomorphic venom phenotype. Mirroring their compositional divergence, the two geographic B. jararaca venom pools showed distinct bioactivity profiles. However, the SAB antivenom manufactured in Vital Brazil Institute neutralized the lethal effect of both venoms to a similar extent. In addition, immobilized SAB antivenom immunocaptured most of the venom components of the venoms of both B. jararaca populations, but did not show immunoreactivity against vasoactive peptides. The Costa Rican bothropic-crotalic-lachesic (BCL) antivenom showed the same lack of reactivity against vasoactive peptides but, in addition, was less efficient immunocapturing PI- and PIII-SVMPs from the SE venom, and bothropstoxin-I, a CRISP molecule, and a D49-PLA2 from the venom of the southern B. jararaca phylogroup. The remarkable paraspecificity exhibited by the Brazilian and the Costa Rican antivenoms indicates large immunoreactive epitope conservation across the natural history of Bothrops, a genus that has its roots in the middle Miocene. This article is part of a Special Issue entitled: Omics Evolutionary Ecolog.
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Affiliation(s)
- Larissa Gonçalves-Machado
- Instituto de Bioquímica Médica, Programa de Biologia Estrutural, Laboratório de Hemostase e Venenos, Universidade Federal do Rio de Janeiro (UFRJ), Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Rede Proteomica do Rio de Janeiro, Universidade Federal do Rio de Janeiro (UFRJ), Brazil; Laboratorio de Venómica Estructural y Funcional, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain
| | - Davinia Pla
- Laboratorio de Venómica Estructural y Funcional, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain.
| | - Libia Sanz
- Laboratorio de Venómica Estructural y Funcional, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain
| | - Roberta Jeane B Jorge
- Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará (UFC), Fortaleza 60430-270, Brazil
| | - Moema Leitão-De-Araújo
- Fundação Zoobotânica do Rio Grande do Sul, Museu de Ciências Naturais, Núcleo Regional de Ofiologia de Porto Alegre, RS, Brazil
| | - Maria Lúcia M Alves
- Fundação Zoobotânica do Rio Grande do Sul, Museu de Ciências Naturais, Núcleo Regional de Ofiologia de Porto Alegre, RS, Brazil
| | - Diego Janisch Alvares
- Laboratorio de Herpetologia, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçãlves 9500, Agronomia, 91501-970 Porto Alegre, RS, Brazil
| | - Joari De Miranda
- Hygeia Biotecnologia Aplicada S.A., Fundação Bio-Rio, Rio de Janeiro, Brazil
| | - Jenifer Nowatzki
- Hygeia Biotecnologia Aplicada S.A., Fundação Bio-Rio, Rio de Janeiro, Brazil
| | - Karen de Morais-Zani
- Laboratorio de Herpetologia, Instituto Butantan, Avenida Vital Brazil 1500, São Paulo 05503-900, SP, Brazil
| | - Wilson Fernandes
- Laboratorio de Herpetologia, Instituto Butantan, Avenida Vital Brazil 1500, São Paulo 05503-900, SP, Brazil
| | | | - Julián Fernández
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Russolina B Zingali
- Instituto de Bioquímica Médica, Programa de Biologia Estrutural, Laboratório de Hemostase e Venenos, Universidade Federal do Rio de Janeiro (UFRJ), Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Rede Proteomica do Rio de Janeiro, Universidade Federal do Rio de Janeiro (UFRJ), Brazil.
| | - José María Gutiérrez
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Carlos Corrêa-Netto
- Instituto de Bioquímica Médica, Programa de Biologia Estrutural, Laboratório de Hemostase e Venenos, Universidade Federal do Rio de Janeiro (UFRJ), Brazil; Instituto Nacional de Biologia Estrutural e Bioimagem, Rede Proteomica do Rio de Janeiro, Universidade Federal do Rio de Janeiro (UFRJ), Brazil; Instituto Vital Brazil, Niterói, Rio de Janeiro, Brazil.
| | - Juan J Calvete
- Laboratorio de Venómica Estructural y Funcional, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain.
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Bp-13 PLA2: Purification and Neuromuscular Activity of a New Asp49 Toxin Isolated from Bothrops pauloensis Snake Venom. Biochem Res Int 2015; 2015:826059. [PMID: 25789175 PMCID: PMC4350628 DOI: 10.1155/2015/826059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/23/2014] [Accepted: 01/02/2015] [Indexed: 11/18/2022] Open
Abstract
A new PLA2 (Bp-13) was purified from Bothrops pauloensis snake venom after a single chromatographic step of RP-HPLC on μ-Bondapak C-18. Amino acid analysis showed a high content of hydrophobic and basic amino acids and 14 half-cysteine residues. The N-terminal sequence showed a high degree of homology with basic Asp49 PLA2 myotoxins from other Bothrops venoms. Bp-13 showed allosteric enzymatic behavior and maximal activity at pH 8.1, 36°–45°C. Full Bp-13 PLA2 activity required Ca2+; its PLA2 activity was inhibited by Mg2+, Mn2+, Sr2+, and Cd2+ in the presence and absence of 1 mM Ca2+. In the mouse phrenic nerve-diaphragm (PND) preparation, the time for 50% paralysis was concentration-dependent (P < 0.05). Both the replacement of Ca2+ by Sr2+ and temperature lowering (24°C) inhibited the Bp-13 PLA2-induced twitch-tension blockade. Bp-13 PLA2 inhibited the contractile response to direct electrical stimulation in curarized mouse PND preparation corroborating its contracture effect. In biventer cervicis preparations, Bp-13 induced irreversible twitch-tension blockade and the KCl evoked contracture was partially, but significantly, inhibited (P > 0.05). The main effect of this new Asp49 PLA2 of Bothrops pauloensis venom is on muscle fiber sarcolemma, with avian preparation being less responsive than rodent preparation. The study enhances biochemical and pharmacological characterization of B. pauloensis venom.
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Floriano RS, Rocha T, Carregari VC, Marangoni S, da Cruz-Höfling MA, Hyslop S, Rodrigues-Simioni L, Rowan EG. The neuromuscular activity of Bothriopsis bilineata smaragdina (forest viper) venom and its toxin Bbil-TX (Asp49 phospholipase A2) on isolated mouse nerve-muscle preparations. Toxicon 2015; 96:24-37. [DOI: 10.1016/j.toxicon.2015.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 12/30/2014] [Accepted: 01/03/2015] [Indexed: 11/16/2022]
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Yoshida EH, Ferraz MC, Tribuiani N, Silva Tavares RVD, Cogo JC, dos Santos MG, Franco LM, Dal-Belo CA, De Grandis RA, Resende FA, Varanda EA, Puebla P, San-Feliciano A, Groppo FC, Oshima-Franco Y. Evaluation of the Safety of Three Phenolic Compounds from <i>Dipteryx alata</i> Vogel with Antiophidian Potential. Chin Med 2015. [DOI: 10.4236/cm.2015.61001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Ferraz MC, Yoshida EH, Tavares RVS, Cogo JC, Cintra ACO, Dal Belo CA, Franco LM, dos Santos MG, Resende FA, Varanda EA, Hyslop S, Puebla P, San Feliciano A, Oshima-Franco Y. An isoflavone from Dipteryx alata Vogel is active against the in vitro neuromuscular paralysis of Bothrops jararacussu snake venom and bothropstoxin I, and prevents venom-induced myonecrosis. Molecules 2014; 19:5790-805. [PMID: 24806579 PMCID: PMC6271625 DOI: 10.3390/molecules19055790] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/22/2014] [Accepted: 04/24/2014] [Indexed: 11/24/2022] Open
Abstract
Snakebite is a neglected disease and serious health problem in Brazil, with most bites being caused by snakes of the genus Bothrops. Although serum therapy is the primary treatment for systemic envenomation, it is generally ineffective in neutralizing the local effects of these venoms. In this work, we examined the ability of 7,8,3'-trihydroxy-4'-methoxyisoflavone (TM), an isoflavone from Dipteryx alata, to neutralize the neurotoxicity (in mouse phrenic nerve-diaphragm preparations) and myotoxicity (assessed by light microscopy) of Bothrops jararacussu snake venom in vitro. The toxicity of TM was assessed using the Salmonella microsome assay (Ames test). Incubation with TM alone (200 μg/mL) did not alter the muscle twitch tension whereas incubation with venom (40 μg/mL) caused irreversible paralysis. Preincubation of TM (200 μg/mL) with venom attenuated the venom-induced neuromuscular blockade by 84% ± 5% (mean ± SEM; n = 4). The neuromuscular blockade caused by bothropstoxin-I (BthTX-I), the major myotoxic PLA2 of this venom, was also attenuated by TM. Histological analysis of diaphragm muscle incubated with TM showed that most fibers were preserved (only 9.2% ± 1.7% were damaged; n = 4) compared to venom alone (50.3% ± 5.4% of fibers damaged; n = 3), and preincubation of TM with venom significantly attenuated the venom-induced damage (only 17% ± 3.4% of fibers damaged; n = 3; p < 0.05 compared to venom alone). TM showed no mutagenicity in the Ames test using Salmonella strains TA98 and TA97a with (+S9) and without (−S9) metabolic activation. These findings indicate that TM is a potentially useful compound for antagonizing the neuromuscular effects (neurotoxicity and myotoxicity) of B. jararacussu venom.
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Affiliation(s)
- Miriéle C Ferraz
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92.5, 18023-000 Sorocaba, SP, Brazil.
| | - Edson H Yoshida
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92.5, 18023-000 Sorocaba, SP, Brazil.
| | - Renata V S Tavares
- Post-Graduate Program in Technological and Environmental Processes, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92.5, 18023-000 Sorocaba, SP, Brazil.
| | - José C Cogo
- Serpentarium of the Vale do Paraíba University (CEN-UNIVAP), Av Shishima Hifumi 2911, 12244-000 São José dos Campos, SP, Brazil.
| | - Adélia C O Cintra
- Department of Clinical, Toxicological and Bromatological Analysis, Faculty of Pharmaceutical Sciences, São Paulo University (USP), Via do Café S/N, 14040-903 Ribeirão Preto, SP, Brazil.
| | - Cháriston A Dal Belo
- LANETOX, Federal University of Pampa (UNIPAMPA), Avenida Antonio Trilha 1847, 97300-000 São Gabriel, RS, Brazil.
| | - Luiz M Franco
- Methodist University of Piracicaba, Rodovia do Açucar, Km 156, 13423-170 Piracicaba, SP, Brazil.
| | - Márcio G dos Santos
- Post-Graduate Course in Environmental Sciences, Federal University of Tocantins (UFT), Av NS 15 ALC NO 14, 109 Norte, 77001-090 Palmas, TO, Brazil.
| | - Flávia A Resende
- Faculty of Pharmaceutical Sciences, São Paulo State University (UNESP), Rodovia Araraquara-Jau, Km 1, 14801-902 Araraquara, SP, Brazil.
| | - Eliana A Varanda
- Faculty of Pharmaceutical Sciences, São Paulo State University (UNESP), Rodovia Araraquara-Jau, Km 1, 14801-902 Araraquara, SP, Brazil.
| | - Stephen Hyslop
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-887 Campinas, SP, Brazil.
| | - Pilar Puebla
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92.5, 18023-000 Sorocaba, SP, Brazil.
| | - Arturo San Feliciano
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92.5, 18023-000 Sorocaba, SP, Brazil.
| | - Yoko Oshima-Franco
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Rodovia Raposo Tavares, Km 92.5, 18023-000 Sorocaba, SP, Brazil.
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Neuromuscular activity of Micrurus laticollaris (Squamata: Elapidae) venom in vitro. Toxins (Basel) 2014; 6:359-70. [PMID: 24445448 PMCID: PMC3920266 DOI: 10.3390/toxins6010359] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 12/20/2013] [Accepted: 12/30/2013] [Indexed: 11/25/2022] Open
Abstract
In this work, we have examined the neuromuscular activity of Micrurus laticollaris (Mexican coral snake) venom (MLV) in vertebrate isolated nerve-muscle preparations. In chick biventer cervicis preparations, the MLV induced an irreversible concentration- and time-dependent (1–30 µg/mL) neuromuscular blockade, with 50% blockade occurring between 8 and 30 min. Muscle contractures evoked by exogenous acetylcholine were completely abolished by MLV, whereas those of KCl were also significantly altered (86% ± 11%, 53% ± 11%, 89% ± 5% and 89% ± 7% for one, three, 10 and 30 µg of venom/mL, respectively; n = 4; p < 0.05). In mouse phrenic nerve-diaphragm preparations, MLV (1–10 µg/mL) promoted a slight increase in the amplitude of twitch-tension (3 µg/mL), followed by neuromuscular blockade (n = 4); the highest concentration caused complete inhibition of the twitches (time for 50% blockade = 26 ± 3 min), without exhibiting a previous neuromuscular facilitation. The venom (3 µg/mL) induced a biphasic modulation in the frequency of miniature end-plate potentials (MEPPs)/min, causing a significant increase after 15 min, followed by a decrease after 60 min (from 17 ± 1.4 (basal) to 28 ± 2.5 (t15) and 12 ± 2 (t60)). The membrane resting potential of mouse diaphragm preparations pre-exposed or not to d-tubocurarine (5 µg/mL) was also significantly less negative with MLV (10 µg/mL). Together, these results indicate that M. laticollaris venom induces neuromuscular blockade by a combination of pre- and post-synaptic activities.
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Floriano RS, Carregari VC, de Abreu VA, Kenzo-Kagawa B, Ponce-Soto LA, da Cruz-Höfling MA, Hyslop S, Marangoni S, Rodrigues-Simioni L. Pharmacological study of a new Asp49 phospholipase A2 (Bbil-TX) isolated from Bothriopsis bilineata smargadina (forest viper) venom in vertebrate neuromuscular preparations. Toxicon 2013; 69:191-9. [DOI: 10.1016/j.toxicon.2013.03.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 02/20/2013] [Accepted: 03/07/2013] [Indexed: 11/30/2022]
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Correia-de-Sá P, Noronha-Matos JB, Timóteo MA, Ferreirinha F, Marques P, Soares AM, Carvalho C, Cavalcante WLG, Gallacci M. Bothropstoxin-I reduces evoked acetylcholine release from rat motor nerve terminals: radiochemical and real-time video-microscopy studies. Toxicon 2012; 61:16-25. [PMID: 23142504 DOI: 10.1016/j.toxicon.2012.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 10/11/2012] [Accepted: 10/18/2012] [Indexed: 02/05/2023]
Abstract
Understanding the biological activity profile of the snake venom components is fundamental for improving the treatment of snakebite envenomings and may also contribute for the development of new potential therapeutic agents. In this work, we tested the effects of BthTX-I, a Lys49 PLA(2) homologue from the Bothrops jararacussu snake venom. While this toxin induces conspicuous myonecrosis by a catalytically independent mechanism, a series of in vitro studies support the hypothesis that BthTX-I might also exert a neuromuscular blocking activity due to its ability to alter the integrity of muscle cell membranes. To gain insight into the mechanisms of this inhibitory neuromuscular effect, for the first time, the influence of BthTX-I on nerve-evoked ACh release was directly quantified by radiochemical and real-time video-microscopy methods. Our results show that the neuromuscular blockade produced by in vitro exposure to BthTX-I (1 μM) results from the summation of both pre- and postsynaptic effects. Modifications affecting the presynaptic apparatus were revealed by the significant reduction of nerve-evoked [(3)H]-ACh release; real-time measurements of transmitter exocytosis using the FM4-64 fluorescent dye fully supported radiochemical data. The postsynaptic effect of BthTX-I was characterized by typical histological alterations in the architecture of skeletal muscle fibers, increase in the outflow of the intracellular lactate dehydrogenase enzyme and progressive depolarization of the muscle resting membrane potential. In conclusion, these findings suggest that the neuromuscular blockade produced by BthTX-I results from transient depolarization of skeletal muscle fibers, consequent to its general membrane-destabilizing effect, and subsequent decrease of evoked ACh release from motor nerve terminals.
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Affiliation(s)
- Paulo Correia-de-Sá
- Instituto de Ciências Biomédicas de Abel Salazar, UMIB, Univ. Porto, 4099-003 Porto, Portugal
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Rey-Suárez P, Floriano RS, Rostelato-Ferreira S, Saldarriaga-Córdoba M, Núñez V, Rodrigues-Simioni L, Lomonte B. Mipartoxin-I, a novel three-finger toxin, is the major neurotoxic component in the venom of the redtail coral snake Micrurus mipartitus (Elapidae). Toxicon 2012; 60:851-63. [DOI: 10.1016/j.toxicon.2012.05.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/04/2012] [Accepted: 05/24/2012] [Indexed: 10/28/2022]
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Galbiatti C, Rocha T, Randazzo-Moura P, Ponce-Soto LA, Marangoni S, Cruz-Höfling MA, Rodrigues-Simioni L. Pharmacological and partial biochemical characterization of Bmaj-9 isolated from Bothrops marajoensis snake venom. J Venom Anim Toxins Incl Trop Dis 2012. [DOI: 10.1590/s1678-91992012000100008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
| | - T Rocha
- State University of Campinas, Brazil
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Huancahuire-Vega S, Ponce-Soto LA, Martins-de-Souza D, Marangoni S. Biochemical and pharmacological characterization of PhTX-I a new myotoxic phospholipase A2 isolated from Porthidium hyoprora snake venom. Comp Biochem Physiol C Toxicol Pharmacol 2011; 154:108-19. [PMID: 21496495 DOI: 10.1016/j.cbpc.2011.03.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/30/2011] [Accepted: 03/31/2011] [Indexed: 01/04/2023]
Abstract
This paper reports the biochemical and pharmacological characterization of a new myotoxic PLA(2) (EC 3.1.1.4) called PhTX-I, purified from Porthidium hyoprora venom by one step analytical chromatography reverse phase HPLC. The homogeneity of the PhTX-I fraction and its molecular mass were initially evaluated by SDS-PAGE and confirmed by MALDI-TOF spectrometry, indicating a molecular mass of 14.249Da and constituted of a single polipeptidic chain. Amino acid sequence was determined by "de novo sequencing," in tandem mass spectrometry, belonging to D49-PLA(2) enzyme class and exhibiting high identity (44-90%) with other myotoxics PLA(2) from snake venoms. The enzymatic investigation showed maximal activity at pH 8 and 35-45°C. This activity was dependent on Ca(2+), other cations (Mg(2+), Mn(2+), Cd(2+) and Zn(2+)) reduced notably the enzymatic activity, suggesting that the arrangement of the catalytic site presents an exclusive structure for Ca(2+). Ex vivo, whole venom and PhTX-I PLA(2) caused blockade of the neuromuscular transmission in young chick biventer cervicis preparations similar to other isolated snake venom toxins from the Bothrops genus. In vivo, both induced local myotoxicity and systemic interleukin-6 response upon intramuscular injection, additionally, induced moderate footpad edema. In vitro, both induced low cytotoxicity in skeletal muscle myoblasts, however PhTX-I PLA(2) was able to lyse myotubes.
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Presynaptic action of Bothriopsis bilineata smargadina (forest viper) venom in vitro. Toxicon 2011; 58:140-5. [DOI: 10.1016/j.toxicon.2011.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 04/29/2011] [Accepted: 05/03/2011] [Indexed: 11/18/2022]
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Dourado DM, Fávero S, Matias R, Carvalho PDTC, da Cruz-Höfling MA. Low-level laser therapy promotes vascular endothelial growth factor receptor-1 expression in endothelial and nonendothelial cells of mice gastrocnemius exposed to snake venom. Photochem Photobiol 2011; 87:418-26. [PMID: 21166811 DOI: 10.1111/j.1751-1097.2010.00878.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Crotalinae snake venoms cause severe local myonecrosis and microvasculature failure at the bite site. We evaluated whether low-level laser therapy (LLLT) could accelerate angiogenesis and myoregeneration in male Swiss mice injected with Bothrops moojeni venom through immunohistochemistry of the vascular endothelial growth factor receptor-1 (VEGFR-1). Envenomed gastrocnemius was either unirradiated (V) or irradiated with HeNe (VHN, 632.8 nm) or GaAs (VGA, 904 nm, 10000 Hz). Animals sacrificed at 3 and 12 h were irradiated once (4 J cm(-2)), at 24 h (twice) and at 3, 7, 21 days (4, 8, 22 times, respectively). At 3 days, LLLT increased angiogenesis (80%:HeNe vs 40%:GaAs), decreased neutrophils and increased proliferation of regenerating cells. However, after 21 days, myoregeneration observed in the VHN group appeared delayed compared with the V group. As LLLT improved revascularization, the suggestive delay in myoregeneration could be a dose-response inhibitory effect caused by multiple irradiations in myogenesis. The immunodetection of VEGFR-1 in neutrophils, macrophages, satellite cells, fibroblasts, Schwann cells and skeletal and smooth muscle fibers (not seen in saline-controls) at only the acute stages of envenoming suggests a mediator role for VEGFR-1 in local alterations. This is the first time that VEGFR-1 expression, and its modulation by photostimulation, has been demonstrated in endothelial and nonendothelial cells of snake envenomed skeletal muscle.
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Affiliation(s)
- Doroty M Dourado
- Departmento de Histologia e Embriologia, Instituto de Biologia, Universidade Estadual de Campinas-UNICAMP, Campinas, SP, Brazil
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Oshima M, Leite GB, Rostelato-Ferreira S, Da Cruz-Höfling MA, Rodrigues-Simioni L, Oshima-Franco Y. Insights of the effects of polyethylene glycol 400 on mammalian and avian nerve terminals. Muscle Nerve 2010; 41:540-6. [PMID: 19941343 DOI: 10.1002/mus.21531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Polyethylene glycol (PEG) has been widely used as a solvent among other applications. An ideal solvent is one that does not interfere with an in vitro biological system, unless it is a bioactive agent. Herein, a facilitatory neurotransmission effect was exhibited by PEG (20 microM) in mammalian (67 +/- 12.5%, n = 4) and avian (74 +/- 6.8%, n = 6) neuromuscular preparations. In curarized preparations, PEG did not reverse the neurotransmission blockade induced by D-tubocurarine (D-Tc, 5.8 microM, n = 6) as promoted by neostigmine (12 microM, n = 4). A possible presynaptic action of PEG was ruled out, because quantal acetylcholine (ACh) content was similar to the control Tyrode-incubated mammalian preparation. PEG showed improved sarcolemmal sensitivity, both under direct (sarcolemma) and indirect stimulation (motor axon), because it was able to release calcium from the sarcoplasmic reticulum, even when 30 microM dantrolene (n = 5) was previously applied. Neurotransmission decreased at a higher PEG concentration (100 microM, n = -6) in the depolarized membrane, but it did not alter normal muscle fiber morphology. In addition, it partially recovered twitch tension amplitude (55 +/- 5.7%) after washing the preparations. More than a simple solvent, we suggest that PEG 400 is able to act on the sarcolemmal membrane, probably at the triad level, which is in line with its well-known ability as drug carrier.
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Affiliation(s)
- Mário Oshima
- Department of Pharmacology, Faculty of Medical Sciences, University of Campinas (UNICAMP), P.O. Box 6111, 13083-970 Campinas, SP, Brazil
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Understanding the in vitro neuromuscular activity of snake venom Lys49 phospholipase A2 homologues. Toxicon 2010; 55:1-11. [DOI: 10.1016/j.toxicon.2009.10.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 07/22/2009] [Accepted: 10/01/2009] [Indexed: 11/24/2022]
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Ponce-Soto LA, Barros JC, Marangoni S, Hernandez S, Dal Belo CA, Corrado AP, Hyslop S, Rodrigues-Simioni L. Neuromuscular activity of BaTX, a presynaptic basic PLA2 isolated from Bothrops alternatus snake venom. Comp Biochem Physiol C Toxicol Pharmacol 2009; 150:291-7. [PMID: 19463969 DOI: 10.1016/j.cbpc.2009.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 11/23/2022]
Abstract
We have previously isolated a Lys49 phospholipase A(2) homolog (BaTX) from Bothrops alternatus snake venom using a combination of molecular exclusion chromatography and reverse phase HPLC and shown its ability to cause neuromuscular blockade. In this work, we describe a one-step procedure for the purification of this toxin and provide further details of its neuromuscular activity. The toxin was purified by reverse phase HPLC and its purity and molecular mass were confirmed by SDS-PAGE, MALDI-TOF mass spectrometry, amino acid analysis and N-terminal sequencing. BaTX (0.007-1.4 microM) produced time-dependent, irreversible neuromuscular blockade in isolated mouse phrenic nerve-diaphragm and chick biventer cervicis preparations (time to 50% blockade with 0.35 microM toxin: 58+/-4 and 24+/-1 min, respectively; n=3-8; mean+/-S.E.) without significantly affecting the response to direct muscle stimulation. In chick preparations, contractures to exogenous acetylcholine (55 and 110 microM) or KCl (13.4 mM) were unaltered after complete blockade by all toxin concentrations. These results, which strongly suggested a presynaptic mechanism of action for this toxin, were reinforced by (1) the inability of BaTX to interfere with the carbachol-induced depolarization of the resting membrane, (2) a significant decrease in the frequency and amplitude of miniature end-plate potentials, and (3) a significant reduction (59+/-4%, n=12) in the quantal content of the end-plate potentials after a 60 min incubation with the toxin (1.4 microM). In addition, a decrease in the organ bath temperature from 37 degrees C to 24 degrees C and/or the replacement of calcium with strontium prevented the neuromuscular blockade, indicating a temperature-dependent effect possibly mediated by enzymatic activity.
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Affiliation(s)
- L A Ponce-Soto
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas , CP 6111, Campinas, SP, Brazil
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Doin-Silva R, Baranauskas V, Rodrigues-Simioni L, da Cruz-Höfling MA. The Ability of Low Level Laser Therapy to Prevent Muscle Tissue Damage Induced by Snake Venom. Photochem Photobiol 2009; 85:63-9. [DOI: 10.1111/j.1751-1097.2008.00397.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Randazzo-Moura P, Ponce-Soto LA, Rodrigues-Simioni L, Marangoni S. Structural Characterization and Neuromuscular Activity of a New Lys49 Phospholipase A2 Homologous (Bp-12) Isolated from Bothrops pauloensis Snake Venom. Protein J 2008; 27:355-62. [DOI: 10.1007/s10930-008-9144-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ramazanova AS, Zavada LL, Starkov VG, Kovyazina IV, Subbotina TF, Kostyukhina EE, Dementieva IN, Ovchinnikova TV, Utkin YN. Heterodimeric neurotoxic phospholipases A2—The first proteins from venom of recently established species Vipera nikolskii: Implication of venom composition in viper systematics. Toxicon 2008; 51:524-37. [DOI: 10.1016/j.toxicon.2007.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 11/01/2007] [Accepted: 11/05/2007] [Indexed: 11/25/2022]
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31
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Cintra-Francischinelli M, Silva MG, Andréo-Filho N, Gerenutti M, Cintra ACO, Giglio JR, Leite GB, Cruz-Höfling MA, Rodrigues-Simioni L, Oshima-Franco Y. Antibothropic action ofCasearia sylvestris Sw. (Flacourtiaceae) extracts. Phytother Res 2008; 22:784-90. [DOI: 10.1002/ptr.2365] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Gomes PC, Machado de Avila RA, Selena Maria W, Richardson M, Fortes-Dias CL, Chávez-Olórtegui C. The co-purification of a lectin (BJcuL) with phospholipases A2 from Bothrops jararacussu snake venom by immunoaffinity chromatography with antibodies to crotoxin. Toxicon 2007; 49:1099-108. [PMID: 17391721 DOI: 10.1016/j.toxicon.2007.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Revised: 01/30/2007] [Accepted: 02/01/2007] [Indexed: 11/29/2022]
Abstract
Antigens of Bothrops jararacussu snake venom cross-reacting with specific antibodies against crotoxin, an Asp49 PLA(2)-containing heterodimeric complex from Crotalus durissus terrificus snake venom, were purified by two steps of immunoaffinity chromatography. The resulting fraction (Bj-F) was shown to be non-toxic (to mice and rabbits) and immunogenic to rabbits. Antibodies raised against Bj-F were able to protect mice against the lethal effect of both B. jararacussu and Crotalus durissus terrificus snake venoms. Then, the procedure developed showed to be useful for the rapid preparation of an antigen able to elicit neutralizing antibodies against the lethal activities of both venoms. Further fractionation of Bj-F revealed the concomitant presence of two major components: BJcuL, a lectin present in B. jararacussu venom, and BthTX-I, a Lys49 PLA(2) homolog, besides other molecules in minor amounts. Our data are discussed and raise the point that the presence of unrelated molecules may be taken into account when immuno-based methods are considered for purification purposes.
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Affiliation(s)
- Paulo César Gomes
- Fundação Ezequiel Dias (FUNED), Rua Conde Pereira Carneiro 80, CEP 30510-010, Belo Horizonte, MG, Brazil
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33
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Ponce-Soto LA, Lomonte B, Gutiérrez JM, Rodrigues-Simioni L, Novello JC, Marangoni S. Structural and functional properties of BaTX, a new Lys49 phospholipase A2 homologue isolated from the venom of the snake Bothrops alternatus. Biochim Biophys Acta Gen Subj 2007; 1770:585-93. [PMID: 17270350 DOI: 10.1016/j.bbagen.2006.11.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Revised: 11/20/2006] [Accepted: 11/21/2006] [Indexed: 10/23/2022]
Abstract
BaTX PLA(2), a K49 phospholipase A(2) homologue was purified from Bothrops alternatus venom after two chromatographic steps, molecular exclusion on Superdex 75 and reverse phase HPLC on mu-Bondapack C-18. A molecular mass of 13898.71 Da was determined by MALDI-TOF mass spectrometry. The amino acid composition showed that BaTX has a high content of Lys, Tyr, Gly, Pro, and 14 half-Cys residues, typical of a basic PLA(2). The complete amino acid sequence of BaTX PLA(2) contains 121 residues, resulting in a calculated pI value of 8.63. This sequence shows high identity values when compared to other K49 PLA(2)s isolated from the venoms of viperid snakes. Lower identity is observed in comparison to D49 PLA(2)s. The sequence was SLFELGKMIL QETGKNPAKS YGAYYCYCGW GGQGQPKDAT DRCCYVHKCC YKKLTGCNPK KDRYSYSWKD KTIVCGENNS CLKELCECDK AVAICLRENL NTYNKKYRYY LKPLCKKADA C. In mice, BaTX induced myonecrosis and edema, upon intramuscular or subcutaneous injections, respectively. The LD(50) of BaTX was 7 mug/g body weight, by intravenous route. In vitro, the toxin caused a potent blockade of neuromuscular transmission in young chicken biventer cervicis preparations. The blockage 50% was achieved at a concentration of 0.03 microM: 40+/-0.4 min and 0.07 microM: 35+/-0.3 min. Moreover, this protein induced a rapid cytolytic effect upon mouse skeletal muscle myoblasts in culture. Thus, the combined structural and functional information obtained identify BaTX as a new member of the K49 PLA(2) family, which presents the typical bioactivities described for such proteins.
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MESH Headings
- Amino Acid Sequence
- Animals
- Bothrops/metabolism
- Cell Line
- Cell Survival/drug effects
- Chickens
- Chromatography, Gel
- Chromatography, High Pressure Liquid
- Crotalid Venoms/enzymology
- Dose-Response Relationship, Drug
- Edema/chemically induced
- In Vitro Techniques
- Isoenzymes/chemistry
- Lethal Dose 50
- Lysine
- Mice
- Molecular Sequence Data
- Molecular Weight
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/pathology
- Myoblasts, Skeletal/drug effects
- Necrosis
- Neuromuscular Junction/drug effects
- Phospholipases A/chemistry
- Phospholipases A/isolation & purification
- Phospholipases A/toxicity
- Phospholipases A2
- Protein Conformation
- Sequence Analysis, Protein
- Sequence Homology, Amino Acid
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Time Factors
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Affiliation(s)
- Luis Alberto Ponce-Soto
- Biochemistry Department, Institute of Biology, Medical Sciences Faculty, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
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Grangeiro MS, Calheiros-Lima AP, Martins MF, Arruda LF, Garcez-do-Carmo L, Santos WC. Pharmacological effects of Eugenia punicifolia (Myrtaceae) in cholinergic nicotinic neurotransmission. JOURNAL OF ETHNOPHARMACOLOGY 2006; 108:26-30. [PMID: 16759829 DOI: 10.1016/j.jep.2006.04.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2005] [Revised: 04/01/2006] [Accepted: 04/13/2006] [Indexed: 05/10/2023]
Abstract
The effects of the aqueous crude extract (5%) of Eugenia punicifolia on cholinergic nicotinic neurotransmission were investigated. Actions of aqueous crude extract over the inhibitory effect of the cholinergic nicotinic antagonists gallamine or pancuronium, on contractions induced by electrical stimulation of phrenic nerve of rat diaphragm, were studied. Tissues were mounted as for isotonic contractions and stimulation was delivered at submaximal voltage. Addition of Eugenia punicifolia did not alter the amplitude of twitch contraction. Gallamine (IC(50): 28.8+/-0.51 microM) or pancuronium (IC(50): 3.16+/-0.11 microM) completely inhibited twitch contractions. After the maximum effect of the antagonists was achieved, addition of the aqueous crude extract (0.5-1.0 mL) totally recovered the responses to electrical stimulation. Neostigmine, a reversible acethylcholinesterase inhibitor, partially recovered responses (49.70+/-6.90% at 1 microM). In another series of experiments, previous incubation of the extract (0.5 mL) shifted to the right inhibitory concentration-response curves for the antagonists gallamine (IC(50) before E. punicifolia: 35.8+/-1.61 microM; IC(50), after E. punicifolia: 2.24+/-0.04 mM) and pancuronium (IC(50), before E. punicifolia: 3.55+/-0.13 microM; IC(50), after E. punicifolia: 0.39+/-0.01 mM). Our results show that the aqueous extract of E. punicifolia recovered the action of competitive nicotinic antagonists at the neuromuscular junction. A receptor-mediated mechanism or the possibilities of interactions of the extract with the enzyme acethylcholinesterase, however, remain to be investigated.
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Zamunér SR, da Cruz-Höfling MA, Corrado AP, Hyslop S, Rodrigues-Simioni L. Comparison of the neurotoxic and myotoxic effects of Brazilian Bothrops venoms and their neutralization by commercial antivenom. Toxicon 2004; 44:259-71. [PMID: 15302532 DOI: 10.1016/j.toxicon.2004.05.029] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2002] [Accepted: 05/13/2004] [Indexed: 10/26/2022]
Abstract
The venoms of some Bothrops species produce neuromuscular blockade in avian and mammalian nerve-muscle preparations in vitro. In this study, we compared the neuromuscular activities (myotoxicity and neurotoxicity) of venoms from several Brazilian species of Bothrops (B. jararaca, B. jararacussu, B. moojeni, B. erythromelas and B. neuwiedi) in chick isolated biventer cervicis muscle preparations and examined their neutralization by commercial antivenom. All of the venoms (50-200 microg/ml, n = 3 - 7 each) induced long-lasting, concentration-dependent muscle contracture and twitch-tension blockade, and also inhibited the muscle responses to acetylcholine and KCl. Preincubation of the venoms (200 microg/ml) with bothropic antivenom (0.2 ml) for 30 min at 37 degrees C prevented the twitch-tension blockade to different extents, with the protection varying from 0.5% (B. neuwiedi) to 88% (B. moojeni). Complete protection against the neuromuscular action of B. neuwiedi venom was observed only with a mixture of bothropic and crotalic antivenoms. The venoms caused either high (B. jararacussu, B. neuwiedi and B. moojeni) or low (B. jararaca and B. erythromelas) creatine kinase release. Morphologically, myonecrosis was greatest with B. jararacussu venom (98-100% of fibers damaged) and least with B. jararaca venom (74% damage). The extent of neutralization by bothropic antivenom was B. jararaca (93%)>B. erythromelas (65.8%)>B. moojeni (30.7%)>B. neuwiedi (20%)>B. jararacussu (no neutralization). Despite this variation in neutralization, enzyme-linked immunosorbent assays indicated similar immunoreactivities for the venoms, although immunoblots revealed quantitative variations in the bands detected. These results show that Bothrops venoms produce varying degrees of neuromuscular blockade in chick nerve-muscle preparations. The variable protection by antivenom against neuromuscular activity indicates that the components responsible for the neuromuscular action may differ among the venoms.
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Affiliation(s)
- Stella R Zamunér
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, P.O. Box 6111, 13083-970, Campinas, SP, Brazil
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