Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 118
Filtrar
1.
Emerg Med Australas ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38660743

RESUMO

OBJECTIVES: Antivenoms are important emergency medications to be held within Australia, particularly in regional and remote locations. We audited current antivenom holdings in hospitals and health services across South Australia (SA) and compared to recommendations in the 'Snakebite and Spiderbite Management Guidelines' from the State's Toxinology service. The process also assessed the feasibility of 'real-time' remote stock monitoring. METHODS: Fifty-three sites listed in the guideline were recommended to hold antivenom, though only 49 are currently operational. Interrogation of antivenom stock for 29 sites was possible using electronic reports generated from the State Pharmacy database. The 20 remaining centres had their stock levels confirmed by calling the centres directly. Data obtained were then compared to recommended levels of antivenom holdings in the guideline with discrepancies and associated costs documented. A separate report verification process was used to determine 'real-time' accuracy of the electronic reports. RESULTS: Thirty-seven sites (75%) held more than the recommended number of antivenom vials, totalling 129 vials in excess with an approximate total cost of $110 000. Twelve sites (24%) held inadequate stock to deliver a treatment dose for 19 envenoming events. The report verification revealed variances in the electronic reports. CONCLUSIONS: This audit has demonstrated a significant disparity between recommended and actual antivenom holdings across most sites in SA and has also revealed that 'real-time' remote monitoring of state antivenom holdings is not currently feasible. Correction of stock levels to that recommended may result in financial benefit for State Health while also addressing inequity in regional and remote healthcare provision.

2.
Toxins (Basel) ; 16(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38535792

RESUMO

Five peptides were isolated from the venom of the Mexican scorpion Centruroides bonito by chromatographic procedures (molecular weight sieving, ion exchange columns, and HPLC) and were denoted Cbo1 to Cbo5. The first four peptides contain 66 amino acid residues and the last one contains 65 amino acids, stabilized by four disulfide bonds, with a molecular weight spanning from about 7.5 to 7.8 kDa. Four of them are toxic to mice, and their function on human Na+ channels expressed in HEK and CHO cells was verified. One of them (Cbo5) did not show any physiological effects. The ones toxic to mice showed that they are modifiers of the gating mechanism of the channels and belong to the beta type scorpion toxin (ß-ScTx), affecting mainly the Nav1.6 channels. A phylogenetic tree analysis of their sequences confirmed the high degree of amino acid similarities with other known bona fide ß-ScTx. The envenomation caused by this venom in mice is treated by using commercially horse antivenom available in Mexico. The potential neutralization of the toxic components was evaluated by means of surface plasmon resonance using four antibody fragments (10FG2, HV, LR, and 11F) which have been developed by our group. These antitoxins are antibody fragments of single-chain antibody type, expressed in E. coli and capable of recognizing Cbo1 to Cbo4 toxins to various degrees.


Assuntos
Animais Peçonhentos , Perciformes , Peçonhas , Humanos , Cricetinae , Animais , Cavalos , Camundongos , Escorpiões , Cricetulus , Escherichia coli , Filogenia , Antivenenos , Aminoácidos , Fragmentos de Imunoglobulinas , Peptídeos
3.
Toxins (Basel) ; 16(2)2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-38393182

RESUMO

Snakebite accident treatment requires the administration of antivenoms that provide efficacy and effectiveness against several snake venoms of the same genus or family. The low number of immunogenic components in venom mixtures that allow the production of antivenoms consequently gives them partial neutralization and a suboptimal pharmacological response. This study evaluates the immunorecognition and neutralizing efficacy of the polyvalent anticoral antivenom from the Instituto Nacional de Salud (INS) of Colombia against the heterologous endemic venoms of Micrurus medemi, and M. sangilensis, and M. helleri by assessing immunoreactivity through affinity chromatography, ELISA, Western blot, and neutralization capability. Immunorecognition towards the venoms of M. medemi and M. sangilensis showed values of 62% and 68% of the protein composition according to the immunoaffinity matrix, respectively. The analysis by Western blot depicted the highest recognition patterns for M. medemi, followed by M. sangilensis, and finally by M. helleri. These findings suggest that the venom compositions are closely related and exhibit similar recognition by the antivenom. According to enzyme immunoassays, M. helleri requires a higher amount of antivenom to achieve recognition than the others. Besides reinforcing the evaluation of INS antivenom capability, this work recommends the use of M. helleri in the production of Colombian antisera.


Assuntos
Antivenenos , Cobras Corais , Animais , Cobras Corais/metabolismo , Colômbia , Venenos Elapídicos/química , Venenos de Serpentes/química
4.
Toxicon ; 238: 107594, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38191031

RESUMO

Successful snakebite envenoming (SBE) treatment requires safe, effective, and quality-assured antivenom products specifically tailored to combat endemic venomous snake species. This study aims to identify the challenges associated with the availability, accessibility, and use of antivenoms for treating SBE. The data for this study were obtained from a cross-sectional study involving healthcare workers from two districts (namely Afram Plains North and Afram Plains South) in the Eastern Region of Ghana. Through the MaxDiff design methodology, we quantify the challenges associated with the availability, accessibility, and use of antivenoms. Responses from a simple random sample of 203 healthcare workers were included in this study. Participants identified the high cost of antivenoms as the most challenging factor that limits the availability, accessibility, and use of antivenoms for treating SBE. Other important challenges were the lack of access to effective antivenoms in remote areas when needed and the increased use of unorthodox and harmful practices, followed by resort to unorthodox and harmful practices and the lack of effective antivenoms to address envenoming from local species in some instances. However, poor outcomes from using substandard antivenoms, stock-outs, inadequate number of manufacturers, and the resort to substandard, cheap, and harmful antivenoms were traded off. Also, poor utilization of antivenoms, suboptimal utilization of antivenoms (low quality, under-dose), use of ineffective, substandard antivenoms, and flooding of the market with products that have not been evaluated thoroughly were underscored. Our findings provide essential data to guide discussions on barriers to the availability, accessibility, and use of antivenoms for treating SBE to improve the supply of antivenoms, enhance the effectiveness of snakebite treatment, and improve patient care quality in Ghana. Multi-component strategies are needed to address the challenges identified, such as intensified advocacy, ongoing education and community engagement, healthcare worker training, and leveraging institutional and governance structures.


Assuntos
Antivenenos , Mordeduras de Serpentes , Animais , Humanos , Antivenenos/uso terapêutico , Mordeduras de Serpentes/epidemiologia , Gana , Estudos Transversais , Serpentes Peçonhentas
5.
Biochimie ; 216: 160-174, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37890695

RESUMO

Crotalus culminatus is a medically significant species of rattlesnake in Mexico [1]. While the proteomic composition of its venom has been previously reported for both juvenile and adult specimens, there has been limited research into its functional properties, with only a few studies, including one focusing on coagulotoxicity mechanisms. In this study, we aimed to compare the biochemical and biological activities of the venom of juvenile and adult snakes. Additionally, we assessed antibody production using the venoms of juveniles and adults as immunogens in rabbits. Our findings reveal lethality and proteolytic activity differences between the venoms of juveniles and adults. Notably, juvenile venoms exhibited high proportions of crotamine, while adult venoms displayed a reduction of this component. A commercially available antivenom demonstrated effective neutralization of lethality of both juvenile and adult venoms in mice. However, it failed to neutralize the paralytic activity induced by crotamine, which, in contrast, was successfully inhibited by antibodies obtained from hyperimmunized rabbits. These results suggest the potential inclusion of C. culminatus venom from juveniles in commercial antivenom immunization schemes to generate antibodies targeting this small myotoxin.


Assuntos
Antivenenos , Venenos de Crotalídeos , Coelhos , Animais , Camundongos , Antivenenos/farmacologia , Crotalus , Proteômica , Venenos de Crotalídeos/toxicidade , Venenos de Crotalídeos/química , Neurotoxinas , México
6.
Academic monograph. São Paulo: Escola Superior do Instituto Butantan; 2024. 61 p.
Tese em Português | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-5347

RESUMO

Animal venoms are produced by specialized glands into their predators and injected in the prey, releasing secretions rich in toxins that are harmful to health. Those venomous animals trigger countless accidents around the world. These include snakebite accidents, which have been included by the World Health Organisation (WHO) in the list of neglected tropical diseases. This public health problem is caused by snakes whose toxins include proteins such as phospholipases A2 (PLA2), enzymes that are widely present in venom and trigger various physiological effects. The treatment recommended by the Ministry of Health is the application of antiophidic serum, which is manufacture based on hyperimmunization carried out on horses capable of neutralizing the action of the venom. However, this procedure has some disadvantages that end up hampering its benefits and effectiveness for victims. Thus, new methods of producing antivenom have been developed with the aim of creating alternative therapies that can improve and minimize problems. Consequently, in silico studies of immunobiologicals are becoming an option to facilitate the development of new antivenoms. This project therefore proposes the use of computational tools to predict epitopes in snake venoms, with a focus on the PLA2 family. Extracting PLA2 protein sequences from databases such as UniProt and the Immune Epitope Database in order to make predictions and classify epitope candidates. As a result, we obtained 17 candidate positions based on in silico analyses and experimental evidence from the literature. It is expect that these approaches will support studies in this area, as they will become an useful tool for developing the next generation of antivenoms.


As peçonhas animais são produzidas por glândulas especializadas em seus predadores, as quais são injetadas nas presas, liberando secreções ricas em toxinas prejudiciais à saúde. Estes animais peçonhentos desencadeiam inúmeros acidentes no mundo todo. Dentre eles, estão os acidentes ofídicos que passaram a ser incluídos pela Organização Mundial da Saúde (OMS) na lista das doenças tropicais negligenciadas. Esse problema de saúde pública é ocasionado pelas serpentes que apresentam na composição de suas toxinas proteínas como as fosfolipases A2 (PLA2), uma das enzimas mais presentes em peçonhas, as quais desencadeiam diversos efeitos fisiológicos. O tratamento preconizado pelo Ministério da Saúde é a aplicação de soro antiofídico, o qual é fabricado a partir da hiperimunização realizada em cavalos capazes de neutralizar a ação do veneno. Entretanto, esse procedimento possui algumas desvantagens que podem diminuir seus benefícios e eficácia às vítimas. Dessa forma, novas elaborações na produção de antiveneno vêm sendo desenvolvidas com intuito de criar terapias alternativas que gerem melhorias e minimizem os problemas. Consequentemente, estudos in silico de imunobiológicos se tornam opções para facilitar o desenvolvimento de novos antivenenos. Em virtude disto, neste projeto propõe o uso de ferramentas computacionais para predição de epítopos em venenos de serpentes com foco na família PLA2. Extraindo sequências proteicas de PLA2 de bancos de dados como UniProt e Immune Epitope Database, a fim de realizar as predições e classificar os candidatos a epítopos. Como resultado obtivemos 17 posições candidatas com base nas análises in sílico e evidências experimentais da literatura. Espera-se que essa abordagem possa auxiliar estudos nessa área, uma vez que se torna uma ferramenta útil para o desenvolvimento da próxima geração de antivenenos.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38142501

RESUMO

Antivenom therapy is a critical intervention for treating the more than 5.000.000 envenomation accidents that occur each year around the world. These immunotherapeutic drugs are mostly produced following techniques developed more than fifty years ago with minor changes. Aggregate content has been described as one of the main causes of early adverse effects after intravenous administration of antivenoms. In this work we propose the introduction of a final polishing step to traditional antivenom manufacturing processes aimed at lowering the aggregate content in the final product. The refinement step proposed in this work is based on the selective capture of immunoglobulin aggregates by a cation exchange monolithic stationary phase. We show that this media can effectively remove aggregates in the final product under isotonic ion-strength and mildly acidic conditions following a negative chromatography strategy, thus making it a useful technique for producing higher quality products.


Assuntos
Antivenenos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Cromatografia , Administração Intravenosa , Cromatografia por Troca Iônica/métodos
8.
Clin Toxicol (Phila) ; 61(9): 656-664, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37988116

RESUMO

INTRODUCTION: Snakebite incidence varies across Europe. However, there is limited research from Central and Southeastern Europe. These regions are notable for the presence of the common European adder (Vipera berus) and the more venomous nose-horned viper (Vipera ammodytes). No standard European antivenom protocol exists. The aim was to assess the epidemiology and treatment of viper bites in this region, focusing on a comparison of bites from Vipera berus and Vipera ammodytes. METHODS: We conducted a prospective multicenter study in Central and Southeastern Europe from 2018 to 2020. This study included poison centres and toxicology-associated hospital wards in Poland, the Czech Republic, Slovakia, Hungary, Slovenia, Croatia, Serbia, and Bulgaria. The following data were collected: age, gender, Vipera species, snakebite site, clinical picture, laboratory results, Audebert's clinical severity grading score, and antivenom therapy. RESULTS: The annual incidence of viper bites in Central and Southeast Europe was estimated at 2.55 bites per million population. Within their respective geographical distribution areas, the incidence of Vipera ammodytes bites (1.61 bites per million population) was higher than Vipera berus bites (1.00 bites per million population). Patients bitten by Vipera ammodytes more frequently reported local pain and developed thrombocytopenia. Antivenom treatment was more commonly administered in Vipera ammodytes bites (72%) compared to Vipera berus bites (39%). The incidence of Vipera ammodytes bites treated with antivenom within its geographical distribution area was three times higher than Vipera berus bites treated with antivenom (1.16 bites per million population versus 0.39 bites per million population). No deaths were reported. CONCLUSIONS: The estimated incidence of viper bites in Central and Southeastern Europe is at least 2.55 per million population. Vipera ammodytes bites are more common and severe, characterized by higher frequencies of pain and thrombocytopenia. Antivenom is needed more often for Vipera ammodytes bites. It is vital that enough European Medicines Agency-approved Vipera ammodytes antivenom is produced and offered affordably.


Assuntos
Mordeduras de Serpentes , Trombocitopenia , Humanos , Antivenenos/uso terapêutico , Estudos Prospectivos , Mordeduras de Serpentes/epidemiologia , Mordeduras de Serpentes/terapia , Europa (Continente)/epidemiologia , Dor
9.
Acta Pharm Sin B ; 13(5): 2234-2249, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37250171

RESUMO

The many-banded krait, Bungarus multicinctus, has been recorded as the animal resource of JinQianBaiHuaShe in the Chinese Pharmacopoeia. Characterization of its venoms classified chief phyla of modern animal neurotoxins. However, the evolutionary origin and diversification of its neurotoxins as well as biosynthesis of its active compounds remain largely unknown due to the lack of its high-quality genome. Here, we present the 1.58 Gbp genome of B. multicinctus assembled into 18 chromosomes with contig/scaffold N50 of 7.53 Mbp/149.8 Mbp. Major bungarotoxin-coding genes were clustered within genome by family and found to be associated with ancient local duplications. The truncation of glycosylphosphatidylinositol anchor in the 3'-terminal of a LY6E paralog released modern three-finger toxins (3FTxs) from membrane tethering before the Colubroidea divergence. Subsequent expansion and mutations diversified and recruited these 3FTxs. After the cobra/krait divergence, the modern unit-B of ß-bungarotoxin emerged with an extra cysteine residue. A subsequent point substitution in unit-A enabled the ß-bungarotoxin covalent linkage. The B. multicinctus gene expression, chromatin topological organization, and histone modification characteristics were featured by transcriptome, proteome, chromatin conformation capture sequencing, and ChIP-seq. The results highlighted that venom production was under a sophisticated regulation. Our findings provide new insights into snake neurotoxin research, meanwhile will facilitate antivenom development, toxin-driven drug discovery and the quality control of JinQianBaiHuaShe.

10.
Toxicon ; 230: 107149, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37187227

RESUMO

Snakebite is a relatively common health condition in Iran with a diverse snake fauna, especially in tropical southern and mountainous western areas of the country with a plethora of snake species. The list of medically important snakes, circumstances and effects of their bite, and necessary medical care require critical appraisal and should be updated regularly. This study aims to review and map the distributions of medically important snake species of Iran, re-evaluate their taxonomy, review their venomics, describe the clinical effects of envenoming, and discuss medical management and treatment, including the use of antivenom. Nearly 350 published articles and 26 textbooks with information on venomous and mildly venomous snake species and snakebites of Iran, were reviewed, many in Persian (Farsi) language, making them relatively inaccessible to an international readership. This has resulted in a revised updated list of Iran's medically important snake species, with taxonomic revisions of some, compilation of their morphological features, remapping of their geographical distributions, and description of species-specific clinical effects of envenoming. Moreover, the antivenom manufactured in Iran is discussed, together with treatment protocols that have been developed for the hospital management of envenomed patients.


Assuntos
Mordeduras de Serpentes , Animais , Mordeduras de Serpentes/tratamento farmacológico , Antivenenos/uso terapêutico , Irã (Geográfico) , Serpentes
11.
Toxicon ; 230: 107152, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37178796

RESUMO

In Colombia, there are two species of bushmaster snakes, Lachesis acrochorda, which is distributed mainly in the west of the country (in the Choco region), and Lachesis muta in the southeast (in the Amazon and Orinoquia region), whose presence has been reduced due to the destruction of their habitats. Captive maintenance is challenging, making it difficult to obtain their venom for study and antivenom manufacturing. They are the largest vipers in the world. The occurrence of human envenomation is quite rare, but when it occurs, it is associated with high mortality. Bushmaster venom is necrotizing, hemorrhagic, myotoxic, hemolytic, and cardiovascular depressant. Due to the presence of bradycardia, hypotension, emesis, and diarrhea in some patients (Lachesis syndrome), the possibility of a vagal or cholinergic effect is raised. The treatment of envenomation is hindered by the scarcity of antivenom and the need to use high doses. A review of the most relevant biological and medical aspects of bushmaster snakes is presented, mainly for those occurring in Colombia, to facilitate their recognition and raise awareness about the need for special attention to improve their conservation and advance scientific knowledge, in particular, about their venom.


Assuntos
Venenos de Crotalídeos , Viperidae , Animais , Humanos , Antivenenos/uso terapêutico , Colômbia
12.
Toxins (Basel) ; 15(4)2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37104202

RESUMO

Bitis arietans is a medically important snake found in Sub-Saharan Africa. The envenomation is characterized by local and systemic effects, and the lack of antivenoms aggravates the treatment. This study aimed to identify venom toxins and develop antitoxins. The F2 fraction obtained from Bitis arietans venom (BaV) demonstrated the presence of several proteins in its composition, including metalloproteases. Titration assays carried out together with the immunization of mice demonstrated the development of anti-F2 fraction antibodies by the animals. The determination of the affinity of antibodies against different Bitis venoms was evaluated, revealing that only BaV had peptides recognized by anti-F2 fraction antibodies. In vivo analyses demonstrated the hemorrhagic capacity of the venom and the effectiveness of the antibodies in inhibiting up to 80% of the hemorrhage and 0% of the lethality caused by BaV. Together, the data indicate: (1) the prevalence of proteins that influence hemostasis and envenomation; (2) the effectiveness of antibodies in inhibiting specific activities of BaV; and (3) isolation and characterization of toxins can become crucial steps in the development of new alternative treatments. Thus, the results obtained help in understanding the envenoming mechanism and may be useful for the study of new complementary therapies.


Assuntos
Mordeduras de Serpentes , Viperidae , Camundongos , Animais , Viperidae/metabolismo , Venenos de Serpentes/metabolismo , Antivenenos , Metaloproteases/metabolismo , Hemorragia , Imunoglobulina G/metabolismo
13.
Toxicon X ; 18: 100152, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36936749

RESUMO

Africa remains one of the regions with the highest incident and burden of snakebite. The goal of the World Health Organization to halve the global burden of snakebite by 2030 can only be achieved if sub-optimal access to antivenoms in the most affected regions is addressed. We identified upstream, midstream, and downstream factors along the antivenom value chain that prevent access to antivenoms in the African region. We identified windows of opportunities that could be utilized to ensure availability, accessibility, and affordability for snakebite endemic populations in Africa. These include implementation of multicomponent strategies such as intensified advocacy, community engagement, healthcare worker trainings, and leveraging the institutional and governance structure provided by African governments to address the challenges identified.

14.
Toxicon X ; 17: 100146, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36619819

RESUMO

The medical humanitarian organization Médecins Sans Frontières (MSF) provides medical care in more than 70 countries and admits more than 7000 cases of snakebite in its facilities each year. We describe our activities against snakebite in three African countries: Central African Republic, South Sudan and Ethiopia, in which different models of care have been developed. A standard protocol using two different antivenoms depending on the patient's syndrome has been introduced, and a simple blood coagulation test is performed to detect venom-induced coagulopathy. Other services, including surgery for necrotizing wounds, are offered in the facilities where MSF admits a large number of snakebite patients. All services, including provision of antivenom, are offered free-of-charge in MSF-supported facilities. Community-based activities focusing on preventive measures and prompt transport to hospital have been developed in a few MSF projects. The provision of quality care and treatment, including effective antivenoms, without out-of-pocket payments by the patients, probably explains why MSF has admitted an increasing number of snakebite victims over the last years. This model requires significant resources and monitoring, including regular training of healthcare workers on treatment protocols and a considerable budget for antivenom procurement.

15.
Toxins, v. 15, n. 4, 264, abr. 2023
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-4897

RESUMO

Bitis arietans is a medically important snake found in Sub-Saharan Africa. The envenomation is characterized by local and systemic effects, and the lack of antivenoms aggravates the treatment. This study aimed to identify venom toxins and develop antitoxins. The F2 fraction obtained from Bitis arietans venom (BaV) demonstrated the presence of several proteins in its composition, including metalloproteases. Titration assays carried out together with the immunization of mice demonstrated the development of anti-F2 fraction antibodies by the animals. The determination of the affinity of antibodies against different Bitis venoms was evaluated, revealing that only BaV had peptides recognized by anti-F2 fraction antibodies. In vivo analyses demonstrated the hemorrhagic capacity of the venom and the effectiveness of the antibodies in inhibiting up to 80% of the hemorrhage and 0% of the lethality caused by BaV. Together, the data indicate: (1) the prevalence of proteins that influence hemostasis and envenomation; (2) the effectiveness of antibodies in inhibiting specific activities of BaV; and (3) isolation and characterization of toxins can become crucial steps in the development of new alternative treatments. Thus, the results obtained help in understanding the envenoming mechanism and may be useful for the study of new complementary therapies.

16.
Acta Pharmaceutica Sinica B ; (6): 2234-2249, 2023.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-982848

RESUMO

The many-banded krait, Bungarus multicinctus, has been recorded as the animal resource of JinQianBaiHuaShe in the Chinese Pharmacopoeia. Characterization of its venoms classified chief phyla of modern animal neurotoxins. However, the evolutionary origin and diversification of its neurotoxins as well as biosynthesis of its active compounds remain largely unknown due to the lack of its high-quality genome. Here, we present the 1.58 Gbp genome of B. multicinctus assembled into 18 chromosomes with contig/scaffold N50 of 7.53 Mbp/149.8 Mbp. Major bungarotoxin-coding genes were clustered within genome by family and found to be associated with ancient local duplications. The truncation of glycosylphosphatidylinositol anchor in the 3'-terminal of a LY6E paralog released modern three-finger toxins (3FTxs) from membrane tethering before the Colubroidea divergence. Subsequent expansion and mutations diversified and recruited these 3FTxs. After the cobra/krait divergence, the modern unit-B of β-bungarotoxin emerged with an extra cysteine residue. A subsequent point substitution in unit-A enabled the β-bungarotoxin covalent linkage. The B. multicinctus gene expression, chromatin topological organization, and histone modification characteristics were featured by transcriptome, proteome, chromatin conformation capture sequencing, and ChIP-seq. The results highlighted that venom production was under a sophisticated regulation. Our findings provide new insights into snake neurotoxin research, meanwhile will facilitate antivenom development, toxin-driven drug discovery and the quality control of JinQianBaiHuaShe.

17.
Molecules ; 27(23)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36500682

RESUMO

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.


Assuntos
Bothrops , Venenos de Crotalídeos , Mordeduras de Serpentes , Animais , Simulação de Acoplamento Molecular , Venenos de Crotalídeos/toxicidade , Antivenenos/farmacologia , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Metaloproteases , Hemorragia/tratamento farmacológico , Edema/induzido quimicamente , Edema/tratamento farmacológico
18.
Toxins (Basel) ; 14(12)2022 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-36548722

RESUMO

Micrurus dumerilii is a coral snake of clinic interest in Colombia. Its venom is mainly composed of phospholipases A2 being MdumPLA2 the most abundant protein. Nevertheless, Micrurus species produce a low quantity of venom, which makes it difficult to produce anticoral antivenoms. Therefore, in this work, we present the recombinant expression of MdumPLA2 to evaluate its biological activities and its immunogenic potential to produce antivenoms. For this, a genetic construct rMdumPLA2 was cloned into the pET28a vector and expressed heterologously in bacteria. His-rMdumPLA2 was extracted from inclusion bodies, refolded in vitro, and isolated using affinity and RP-HPLC chromatography. His-rMdumPLA2 was shown to have phospholipase A2 activity, a weak anticoagulant effect, and induced myonecrosis and edema. The anti-His-rMdumPLA2 antibodies produced in rabbits recognized native PLA2, the complete venom of M. dumerilii, and a phospholipase from another species of the Micrurus genus. Antibodies neutralized 100% of the in vitro phospholipase activity of the recombinant toxin and a moderate percentage of the myotoxic activity of M. dumerilii venom in mice. These results indicate that His-rMdumPLA2 could be used as an immunogen to improve anticoral antivenoms development. This work is the first report of an M. dumerilii functional recombinant PLA2.


Assuntos
Antivenenos , Cobras Corais , Venenos Elapídicos , Fosfolipases A2 , Animais , Camundongos , Coelhos , Antivenenos/biossíntese , Antivenenos/genética , Antivenenos/imunologia , Venenos Elapídicos/enzimologia , Fosfolipases A2/biossíntese , Fosfolipases A2/genética , Fosfolipases A2/imunologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia
19.
Toxins (Basel) ; 14(12)2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36548772

RESUMO

In Colombia, South America, there is a subspecies of the South American rattlesnake Crotalus durissus, C. d. cumanensis, a snake of the Viperidae family, whose presence has been reduced due to the destruction of its habitat. It is an enigmatic snake from the group of pit vipers, venomous, with large articulated front fangs, special designs on its body, and a characteristic rattle on its tail. Unlike in Brazil, the occurrence of human envenomation by C. durisus in Colombia is very rare and contributes to less than 1% of envenomation caused by snakes. Its venom is a complex cocktail of proteins with different biological effects, which evolved with the purpose of paralyzing the prey, killing it, and starting its digestive process, as well as having defense functions. When its venom is injected into humans as the result of a bite, the victim presents with both local tissue damage and with systemic involvement, including a diverse degree of neurotoxic, myotoxic, nephrotoxic, and coagulopathic effects, among others. Its biological effects are being studied for use in human health, including the possible development of analgesic, muscle relaxant, anti-inflammatory, immunosuppressive, anti-infection, and antineoplastic drugs. Several groups of researchers in Brazil are very active in their contributions in this regard. In this work, a review is made of the most relevant biological and medical aspects related to the South American rattlesnake and of what may be of importance for a better understanding of the snake C. d. cumanensis, present in Colombia and Venezuela.


Assuntos
Venenos de Crotalídeos , Crotalus , Animais , Humanos , Crotalus/metabolismo , Colômbia , Venenos de Crotalídeos/toxicidade , Venenos de Crotalídeos/metabolismo , Brasil , População da América do Sul
20.
RECIIS (Online) ; 16(4): 986-989, out.-dez. 2022.
Artigo em Português | LILACS | ID: biblio-1411172

RESUMO

O livro Os animais peçonhentos na saúde pública expõe um vasto histórico de acidentes envolvendo problemas de saúde provocados por animais peçonhentos. Os autores resgatam trabalhos e vivências, descritos por Louis Pasteur e Vital Brazil, fundamentais para o desenvolvimento de processos da ciência translacional como compreendida hoje, no século XXI. A obra é marcada pela defesa da necessidade de políticas públicas coerentes que sejam capazes de promover ações de capacitação, prevenção, diagnóstico, tratamento e reabilitação dos pacientes.


The book Os animais peçonhentos na saúde pública presents a vast history of accidents involving health problems caused by venomous animals. The authors rescue works and experiences, described by Louis Pasteur and Vital Brazil, fundamental for the development of translational science processes as understood today, in the 21st century. The work is marked by the defense of the need for coherent public policies capable of promoting training, prevention, diagnosis, treatment and rehabilitation of patients.


El libro Os animais peçonhentos na saúde pública expone una vasta historia de accidentes que involucran problemas de salud causados por animals venenosos. Los autores rescatan obras y experiencias, descritas por Louis Pasteur y Vital Brazil, fundamentales para el desarrollo de los procesos de ciencia translacional tal como se entienden hoy, en el siglo XXI. El libro está marcado por la defensa de la necesidad de políticas públicas coherentes capaces de promover la formación, la prevención, el diagnóstico, el tratamiento y la rehabilitación de los pacientes.


Assuntos
Humanos , Animais Peçonhentos , Pacientes , Venenos , Mordeduras e Picadas , Saúde Pública , Imunização Passiva , Assistência Centrada no Paciente , Ciência Translacional Biomédica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...