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2.
Toxicon ; 241: 107683, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38460604

RESUMO

OBJECTIVE: To establish a preclinical large-animal model of Deinagkistrodon acutus snakebite envenomation and evaluate its feasibility. METHODS: The venom of D. acutus (0 mg/kg, 1 mg/kg, 2 mg/kg, 5 mg/kg, or 10 mg/kg) was injected into the left biceps femoris of 11 male pigs. Then, the circumferences of the limbs were regularly measured, and changes in muscle injury biomarkers, blood parameters, coagulation function, vital organ function and injury biomarkers were regularly detected. At 24 h after venom injection, the animals were euthanized, and the pathological damage to the vital organs mentioned above was evaluated. RESULTS: The two pigs receiving 10 mg/kg and 5 mg/kg snake venom died at 8 h and 12 h after injection, respectively. The remaining pigs were equally divided into 0 mg/kg, 1 mg/kg, and 2 mg/kg snake venom groups, and all of them survived to 24 h after injection. Compared with the pigs receiving 0 mg/kg snake venom, the pigs receiving 1 mg/kg or 2 mg/kg snake venom exhibited significant abnormities, including limb swelling; increased muscle injury biomarker creatine kinase (CK) and coagulation function indicators prothrombin time and D-dimer; and decreased blood routine indicator platelet and coagulation function indicator fibrinogen. Moreover, significant abnormalities in myocardial and cerebral function and injury biomarkers in the heart, brain, liver, kidney and intestine were also observed. In particular, the abnormalities mentioned above were significantly obvious in those pigs receiving 2 mg/kg snake venom. Pathological evaluation revealed that the morphology of muscle, heart, brain, liver, kidney, and intestine in those pigs receiving 0 mg/kg snake venom was normal; however, pathological damage was observed in those pigs receiving 1 mg/kg and 2 mg/kg snake venom. Similarly, the pathological damage was more severe in those pigs receiving 2 mg/kg snake venom. CONCLUSION: The intramuscular injection of 2 mg/kg D. acutus venom seems to be an optimal dose for examining the preclinical efficacy of existing and novel therapeutics for treating D. acutus envenomation in pigs.


Assuntos
Crotalinae , Mordeduras de Serpentes , 60573 , Masculino , Animais , Suínos , Mordeduras de Serpentes/tratamento farmacológico , Mordeduras de Serpentes/veterinária , Mordeduras de Serpentes/patologia , Venenos de Serpentes/toxicidade , Biomarcadores
3.
Toxicon ; 241: 107681, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38461896

RESUMO

INTRODUCTION: The deaths from and morbidities associated with snakebites - amputations, loss of function in the limb, visible scarring or tissue damage - have a vast economic, social, and psychological impact on indigenous communities in the Brazilian Amazon, especially children, and represent a real and pressing health crisis in this population. Snakebite clinical and research experts have therefore proposed expanding antivenom access from only hospitals to include the community health centers (CHC) located near and within indigenous communities. However, there are no studies examining the capacity of CHCs to store, administer, and manage antivenom treatment. In response to this gap, the research team calling for antivenom decentralization developed and validated an expert-based checklist outlining the minimum requirements for a CHC to provide antivenom. METHODS: The objective of this study was thus to survey a sample of CHCs in indigenous territories and evaluate their capacity to provide antivenom treatment according to this accredited checklist. The checklist was administered to nurses and doctors from 16 CHCs, two per indigenous district in Amazonas/Roraima states. RESULTS: Our results can be conceptualized into three central findings: 1) most CHCs have the capacity to provide antivenom treatment, 2) challenges to capacity are human resources and specialized items, and 3) antivenom decentralization is feasible and appropriate in indigenous communities. CONCLUSION: Decentralization would provide culturally and contextually appropriate care accessibility to a historically marginalized and underserved population of the Brazilian Amazon. Future studies should examine optimal resource allocation in indigenous territories and develop an implementation strategy in partnership with indigenous leaders. Beyond the indigenous population, the checklist utilized could be applied to community health centers treating the general population and/or adapted to other low-resource settings.


Assuntos
Mordeduras de Serpentes , Criança , Humanos , Mordeduras de Serpentes/tratamento farmacológico , Mordeduras de Serpentes/epidemiologia , Antivenenos/uso terapêutico , Brasil/epidemiologia , Inquéritos e Questionários , Centros Comunitários de Saúde
4.
PLoS Negl Trop Dis ; 18(3): e0012070, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38527073

RESUMO

Snakebite envenomation is a significant global health issue that requires specific antivenom treatments. In Taiwan, available antivenoms target a variety of snakes, but none specifically target Trimeresurus gracilis, an endemic and protected species found in the high mountain areas of Taiwan. This study evaluated the effectiveness of existing antivenoms against T. gracilis venom, focusing on a bivalent antivenom developed for Trimeresurus stejnegeri and Protobothrops mucrosquamatus (TsPmAV), as well as monovalent antivenoms for Deinagkistrodon acutus (DaAV) and Gloydius brevicaudus (GbAV). Our research involved in vivo toxicity testing in mice and in vitro immunobinding experiments using (chaotropic) enzyme-linked immunosorbent assays, comparing venoms from four pit viper species (T. gracilis, T. stejnegeri, P. mucrosquamatus, and D. acutus) with three types of antivenoms. These findings indicate that TsPmAV partially neutralized T. gracilis venom, marginally surpassing the efficacy of DaAV. In vitro tests revealed that GbAV displayed higher binding capacities toward T. gracilis venom than TsPmAV or DaAV. Comparisons of electrophoretic profiles also reveal that T. gracilis venom has fewer snake venom C-type lectin like proteins than D. acutus, and has more P-I snake venom metalloproteases or fewer phospholipase A2 than G. brevicaudus, T. stejnegeri, or P. mucrosquamatus. This study highlights the need for antivenoms that specifically target T. gracilis, as current treatments using TsPmAV show limited effectiveness in neutralizing local effects in patients. These findings provide crucial insights into clinical treatment protocols and contribute to the understanding of the evolutionary adaptation of snake venom, aiding in the development of more effective antivenoms for human health.


Assuntos
Crotalinae , Mordeduras de Serpentes , Trimeresurus , 60573 , Humanos , Camundongos , Animais , Antivenenos/uso terapêutico , Venenos de Serpentes , Mordeduras de Serpentes/tratamento farmacológico , Venenos de Víboras/toxicidade
5.
Commun Biol ; 7(1): 358, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38519650

RESUMO

Snakebite envenoming is an important public health issue responsible for mortality and severe morbidity. Where mortality is mainly caused by venom toxins that induce cardiovascular disturbances, neurotoxicity, and acute kidney injury, morbidity is caused by toxins that directly or indirectly destroy cells and degrade the extracellular matrix. These are referred to as 'tissue-damaging toxins' and have previously been classified in various ways, most of which are based on the tissues being affected (e.g., cardiotoxins, myotoxins). This categorisation, however, is primarily phenomenological and not mechanistic. In this review, we propose an alternative way of classifying cytotoxins based on their mechanistic effects rather than using a description that is organ- or tissue-based. The mechanisms of toxin-induced tissue damage and their clinical implications are discussed. This review contributes to our understanding of fundamental biological processes associated with snakebite envenoming, which may pave the way for a knowledge-based search for novel therapeutic options.


Assuntos
Mordeduras de Serpentes , Humanos , Mordeduras de Serpentes/tratamento farmacológico , Venenos de Serpentes/toxicidade , Venenos de Serpentes/uso terapêutico , Matriz Extracelular , Saúde Pública
6.
Biomed Pharmacother ; 173: 116290, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38458010

RESUMO

Jatropha mollissima (Pohl) Baill. (Euphorbiaceae) is widely used in traditional medicine to treat inflammatory disorders. So, a topical gel containing the hydroethanolic extract of its leaves was developed and evaluated for its anti-inflammatory, wound healing, and antiophidic properties in mice. First, the chemical profile of different parts of the plant was characterized by liquid chromatography coupled to mass spectrometry (LC-MS) using molecular networking. In the leaf extract, 11 compounds were characterized, with a particular emphasis on the identification of flavonoids. The gel efficiently inhibited carrageenan-induced paw edema, as well as acute and chronic croton oil-induced ear edema models, thereby reducing inflammatory and oxidative parameters in inflamed tissues. Besides anti-inflammatory activity, the herbal gel showed significant wound healing activity. The edematogenic, hemorrhagic and dermonecrotic activities induced by Bothrops jararaca snake venom were effectively inhibited by the treatment with J. mollissima gel. The association with the herbal gel improved in up to 90% the efficacy of commercial snake antivenom in reduce venom-induced edema. Additionally, while antivenom was not able to inhibit venom-induced dermonecrosis, treatment with herbal gel reduced in 55% the dermonocrotic halo produced. These results demonstrate the pharmacological potential of the herbal gel containing J. mollissima extract, which could be a strong candidate for the development of herbal products that can be used to complement the current antivenom therapy against snake venom local toxicity.


Assuntos
Venenos de Crotalídeos , Euphorbiaceae , Jatropha , Mordeduras de Serpentes , Animais , Camundongos , Euphorbiaceae/química , Antivenenos/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/química , Jatropha/química , Composição de Medicamentos , Mordeduras de Serpentes/tratamento farmacológico , Edema/induzido quimicamente , Edema/tratamento farmacológico , Anti-Inflamatórios/efeitos adversos , 60561 , Cicatrização
7.
Trends Immunol ; 45(4): 225-227, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38538486

RESUMO

Snakebite envenomings kill ~100 000 victims each year and leave many more with permanent sequelae. Antivenoms have been available for more than 125 years but are in need of innovation. A new study by Khalek et al. highlights broadly neutralizing human monoclonal antibodies (mAbs) that might be used to develop recombinant antivenoms with superior therapeutic benefits.


Assuntos
Antivenenos , Mordeduras de Serpentes , Humanos , Animais , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Anticorpos Monoclonais/uso terapêutico , Serpentes
8.
Toxicon ; 242: 107694, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38556061

RESUMO

Snakebite envenomation often leads to severe visceral injuries, including acute liver injury (ALI). However, the toxicity mechanism remains unclear. Moreover, varespladib can directly inhibit phospholipase A2 (PLA2) in snake venom, but its protective effect on snakebite-induced ALI and the mechanism have not been clarified. Previous studies have shown that snake venom PLA2 leads to neuron cell death via reactive oxygen species (ROS), one of the initial factors related to the mitophagy pathway. The present study group also found that ROS accumulation occurred after Naja atra envenoming. Hematoxylin and eosin (H/E) staining and immunohistochemistry (IHC) were performed to identify the expression of inflammatory factors in the liver tissue, and flow cytometry and immunofluorescence were used to detect ROS levels and mitochondrial function. Immunofluorescence and western blotting were also used for detecting mitophagy pathway-related proteins. The results showed that N. atra bite induced ALI by activating mitophagy and inducing inflammation and that varespladib had a protective effect. Collectively, these results showed the pathological mechanism of ALI caused by N. atra bite and revealed the protective effect of varespladib.


Assuntos
Acetatos , Indóis , Mitofagia , Fosfolipases A2 , Mordeduras de Serpentes , Animais , Camundongos , Mitofagia/efeitos dos fármacos , Fosfolipases A2/metabolismo , Mordeduras de Serpentes/tratamento farmacológico , Mordeduras de Serpentes/complicações , Cetoácidos/farmacologia , Masculino , Espécies Reativas de Oxigênio/metabolismo , Venenos Elapídicos/toxicidade , Fígado/efeitos dos fármacos , Fígado/patologia , Doença Hepática Induzida por Substâncias e Drogas
9.
BMJ Glob Health ; 9(3)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38485142

RESUMO

INTRODUCTION: Antivenom is a lifesaving medicine for treating snakebite envenoming, yet there has been a crisis in antivenom supply for many decades. Despite this, substantial quantities of antivenom stocks expire before use. This study has investigated whether expired antivenoms retain preclinical quality and efficacy, with the rationale that they could be used in emergency situations when in-date antivenom is unavailable. METHODS: Using WHO guidelines and industry test requirements, we examined the in vitro stability and murine in vivo efficacy of eight batches of the sub-Saharan African antivenom, South African Institute for Medical Research polyvalent, that had expired at various times over a period of 30 years. RESULTS: We demonstrate modest declines in immunochemical stability, with antivenoms older than 25 years having high levels of turbidity. In vitro preclinical analysis demonstrated all expired antivenoms retained immunological recognition of venom antigens and the ability to inhibit key toxin families. All expired antivenoms retained comparable in vivo preclinical efficacy in preventing the lethal effects of envenoming in mice versus three regionally and medically important venoms. CONCLUSIONS: This study provides strong rationale for stakeholders, including manufacturers, regulators and health authorities, to explore the use of expired antivenom more broadly, to aid in alleviating critical shortages in antivenom supply in the short term and the extension of antivenom shelf life in the longer term.


Assuntos
Antivenenos , Mordeduras de Serpentes , Camundongos , Humanos , Animais , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Peçonhas/uso terapêutico
10.
Toxicon ; 241: 107662, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38417708

RESUMO

Snakebite envenomation is a life-threatening condition and antivenoms are used as the most effective treatment. Venom obtained from snakes in long-term captivity showed some variations in comparison to the venom of the wild snakes. The objective of this study is to compare the venom of the Pseudocerastes persicus under long-term captivity and wild conditions as well as the antivenom obtained from these venoms. We have analyzed venom samples and produced trivalent antivenoms using the venom of long-term captive (LTC) or recently wild-captured (RWC) Pseudocerastes persicus, and RWC Macrovipera lebetina, and Echis carinatus. The HPLC analysis revealed that the RWC snakes' venom had three peaks that were not present in the LTC snake's venom. Further analysis using MALDI-TOF and MS/MS showed that the fraction with a retention time (RT) of 14 min contained a toxin from the Kunitz-type serine protease inhibitor (KUT) class, while the fraction with RT 21 a peptide identified within the snake venom metalloproteinase (SVMP) class. The third peak was identified as a sphingolipid. Interestingly, the in vivo preclinical tests showed no significant differences in the effectiveness of the antivenoms. which could be due to the cross-immunogenicity or cross-reactivity between different toxins in the venom. According to our results, small variations in the venom composition of a species do not lead to a decrease in the efficacy of the polyvalent antivenom.


Assuntos
Antivenenos , Mordeduras de Serpentes , Animais , Antivenenos/uso terapêutico , Espectrometria de Massas em Tandem , Serpentes , Venenos de Serpentes , Cromatografia Líquida de Alta Pressão , Mordeduras de Serpentes/tratamento farmacológico , Mordeduras de Serpentes/veterinária
11.
Sci Rep ; 14(1): 3184, 2024 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-38326450

RESUMO

Local tissue damage following snakebite envenoming remains a poorly researched area. To develop better strategies to treat snakebites, it is critical to understand the mechanisms through which venom toxins induce envenomation effects including local tissue damage. Here, we demonstrate how the venoms of two medically important Indian snakes (Russell's viper and cobra) affect human skeletal muscle using a cultured human myoblast cell line. The data suggest that both venoms affect the viability of myoblasts. Russell's viper venom reduced the total number of cells, their migration, and the area of focal adhesions. It also suppressed myogenic differentiation and induced muscle atrophy. While cobra venom decreased the viability, it did not largely affect cell migration and focal adhesions. Cobra venom affected the formation of myotubes and induced atrophy. Cobra venom-induced atrophy could not be reversed by small molecule inhibitors such as varespladib (a phospholipase A2 inhibitor) and prinomastat (a metalloprotease inhibitor), and soluble activin type IIb receptor (a molecule used to promote regeneration of skeletal muscle), although the antivenom (raised against the Indian 'Big Four' snakes) has attenuated the effects. However, all these molecules rescued the myotubes from Russell's viper venom-induced atrophy. This study demonstrates key steps in the muscle regeneration process that are affected by both Indian Russell's viper and cobra venoms and offers insights into the potential causes of clinical features displayed in envenomed victims. Further research is required to investigate the molecular mechanisms of venom-induced myotoxicity under in vivo settings and develop better therapies for snakebite-induced muscle damage.


Assuntos
Víbora de Russell , Mordeduras de Serpentes , Humanos , Animais , Naja naja , Mordeduras de Serpentes/tratamento farmacológico , Venenos de Víboras/toxicidade , Elapidae , Venenos Elapídicos/farmacologia , Venenos Elapídicos/uso terapêutico , Mioblastos , Atrofia
12.
Toxicon ; 240: 107638, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38311255

RESUMO

BACKGROUND: Platyceps ventromaculatus is a non-front-fanged colubrid snake of unknown medical significance. In this study, we highlight the clinical manifestations and outcomes of P. ventromaculatus bites. We also emphasise the need to create awareness among clinicians and the public for its potential to be confused with serious venomous bites such as Echis carinatus sochureki. METHODS: This series is part of an ongoing observational clinical study from our tertiary care hospital in Jodhpur, India on the profile and outcomes of snakebite envenoming. Data was collected after approval from Institute Ethics Committee. The date and time of the bite, geographical location, type of human-snake conflict, time-to-reach a healthcare facility, antivenom used (dose), and outcomes were recorded. We retrospectively examined our clinical data for images suggestive of P. ventromaculatus and present the clinical details of these patients. The photographs were identified utilising taxonomic keys for species identification. RESULTS: A total of four images and three patients with bites due to P. ventromaculatus were identified. The clinical effects included mild local erythema, pain, transient local bleeding, and edema. All bites occurred during daylight hours, 2 during agricultural activities, and one at home. Twenty-minute Whole Blood Clotting Test was persistently prolonged for 12 h after the bite in one patient. All patients were treated symptomatically, observed at the emergency department, and discharged within 24 h. None of the patients received antivenom. CONCLUSIONS: To our knowledge, P. ventromaculatus has so far not been reported to result in envenoming or medically significant bites. This study highlights that Platyceps bite can present with clinically significant local and possibly systemic findings that may lead to confusion with saw-scaled viper (Echis) envenoming. Clinicians must receive appropriate training so as to be aware and recognize regional snake species that do not require antivenom so as to avoid unnecessary antivenom administration.


Assuntos
Colubridae , 60567 , Mordeduras de Serpentes , 60573 , Animais , Humanos , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Estudos Retrospectivos , Índia/epidemiologia
13.
Sci Transl Med ; 16(735): eadk1867, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38381847

RESUMO

Snakebite envenoming is a major global public health concern for which improved therapies are urgently needed. The antigenic diversity present in snake venom toxins from various species presents a considerable challenge to the development of a universal antivenom. Here, we used a synthetic human antibody library to find and develop an antibody that neutralizes long-chain three-finger α-neurotoxins produced by numerous medically relevant snakes. Our antibody bound diverse toxin variants with high affinity, blocked toxin binding to the nicotinic acetylcholine receptor in vitro, and protected mice from lethal venom challenge. Structural analysis of the antibody-toxin complex revealed a binding mode that mimics the receptor-toxin interaction. The overall workflow presented is generalizable for the development of antibodies that target conserved epitopes among antigenically diverse targets, and it offers a promising framework for the creation of a monoclonal antibody-based universal antivenom to treat snakebite envenoming.


Assuntos
Antivenenos , Mordeduras de Serpentes , Humanos , Animais , Camundongos , Antivenenos/química , Mordeduras de Serpentes/tratamento farmacológico , Neurotoxinas/toxicidade , Anticorpos Amplamente Neutralizantes , Venenos de Serpentes
14.
Wilderness Environ Med ; 35(1): 82-87, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38379491

RESUMO

Snakebite is a significant public health issue in which venom-induced consumption coagulopathy is a common and serious complication that results from the activation of the coagulation pathway by snake toxins. We report a male patient, 56 y old, who was thought to have been bitten by a snake on his left foot. He was transported to a nearby hospital where he received analgesics and 3 snake polyvalent antivenom vials, and then he was transported to our hospital after 12 h. He presented with 2 small puncture wounds, pain, blistering, and edema of the left foot. On the 2nd day, the patient developed gingival bleeding and hematuria. Laboratory investigations upon admission revealed prothrombin time (PT) of more than 3 min, prothrombin concentration (PC) of less than 2.5%, and an international normalized ratio (INR) of 23.43. Further investigation of urine showed more than 100 RBCs. Despite receiving 16 packs of plasma and 40 snake polyvalent antivenom vials manufactured by VACSERA over 3 days, hemoglobin concentration and platelet count decreased with the appearance of jaundice, lactate dehydrogenase was 520, and reticulocytes were 3.5%. PT was more than 300 s, and INR was still over range. Plasmapheresis and corticosteroids were provided, which improved the patient's general condition, PT, PC, and INR, and the patient was discharged after 6 days of hospital stay. This case report indicated that plasmapheresis and corticosteroids were clinically efficient approaches in the management of snake envenomation unresponsive to antivenom.


Assuntos
Antivenenos , Mordeduras de Serpentes , Humanos , Masculino , Corticosteroides , Antivenenos/uso terapêutico , Egito , Plasmaferese , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/tratamento farmacológico , Pessoa de Meia-Idade
15.
Toxins (Basel) ; 16(1)2024 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-38251253

RESUMO

Even though there are guidelines for the management of snakebite envenoming (SBE), the use of antibiotics in this pathology remains controversial. The aim of this study is to provide a narrative review of the literature and recommendations based on the best available evidence regarding antibiotic use in SBE. We performed a narrative review of relevant literature regarding SBE and antibiotic use as prophylaxis or treatment. A total of 26 articles were included. There is wide use of antibiotics in SBE; nevertheless, infection was not necessarily documented. The antibiotics used varied according to the study, from beta lactams to lincosamide and nitroimidazoles, and from monotherapy to combined antimicrobials. The most common recommendations were to manage skin and soft tissue infections and avoid infectious complications, but these suggestions are not necessarily based on bacteriological findings. Prophylactic use of antibiotics in SBE is discouraged in most studies. Antibiotic prescription in SBE should be based on the susceptibility of microorganisms isolated from the affected tissue or identified in snakes' oral cavities. Antibiotics should be reserved only for patients with a demonstrated infection, or those at a high risk of developing an infection, i.e., presenting severe local envenoming, local signs of infection, or those with incorrect manipulation of wounds. Prospective studies are needed to correlate microbiological findings at the wound site and the response to antibiotic use.


Assuntos
Gestão de Antimicrobianos , Nitroimidazóis , Mordeduras de Serpentes , Humanos , Antibacterianos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Boca
16.
J Ethnopharmacol ; 323: 117671, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38163555

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Snake bites are a critical health issue in many parts of the world particularly in Asian countries lacking efficient health facilities in rural areas. Cobra is the most common snake type in Asia and is responsible for a large number of mortalities particularly in rural areas. Plants are usually considered the most effective and easy-to-approach treatment for snake bites in rural areas of various countries. Vitex negundo L. is an important medicinal plant traditionally used to treat snake bite envenomation in many countries of Asia. AIM OF THE STUDY: From literature survey of plants traditionally used in the treatment of snake bites in Asian countries including India, Pakistan and Sri Lanka, roots of V. negundo were selected for the present study. Anti-snake venom potential of its roots was assessed through various in vitro assays targeting the phospholipase A2 enzyme. MATERIALS AND METHODS: V. negundo roots were sequentially extracted in different organic solvents to get fractions and in methanol to get total extract. The extracts were evaluated for phospholipase A2 (PLA2) inhibitory potential through inhibition of venom-induced hemolysis, ADP-induced platelet aggregation, PLA2-induced fatty acid hydrolysis and anticoagulant effect of cobra venom. Antioxidant power was determined using DPPH and superoxide radical scavenging assays. GC-MS and HPLC analysis was performed for the total methanol extract. RESULTS: Strong PLA2 inhibitory effect was observed for all the extracts. The ethyl acetate, acetone and methanol fractions significantly inhibited toxic effects of cobra venom under in vitro conditions. Radical scavenging potential of these fractions was also significantly high as compared to non-polar fractions in both DPPH and superoxide scavenging assays. Phytochemical analysis indicated high phenolic and flavonoid contents in these fractions. GC-MS and HPLC analysis of total methanol extract confirmed the presence of bis(2-ethylhexyl) phthalate, phenol, o-Guaiacol, palmitic acid-methyl ester, methyl stearate, quercetin and kaempferol in the plant. CONCLUSION: The study concluded that the roots of V. negundo, particularly their polar extracts, have strong PLA2 inhibitory effect against cobra venom confirming their traditional use to manage snake bites. The roots of this plant can be further studied for isolation of plant-based antisera.


Assuntos
Mordeduras de Serpentes , Vitex , Humanos , Mordeduras de Serpentes/tratamento farmacológico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/química , Metanol/uso terapêutico , Antivenenos/farmacologia , Venenos Elapídicos , Fosfolipases A2 , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Fosfolipases , Paquistão
17.
PLoS Negl Trop Dis ; 18(1): e0011825, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38190386

RESUMO

Snake envenoming is a major, but neglected, tropical disease. Among venomous snakes, those inducing neurotoxicity such as kraits (Bungarus genus) cause a potentially lethal peripheral neuroparalysis with respiratory deficit in a large number of people each year. In order to prevent the development of a deadly respiratory paralysis, hospitalization with pulmonary ventilation and use of antivenoms are the primary therapies currently employed. However, hospitals are frequently out of reach for envenomated patients and there is a general consensus that additional, non-expensive treatments, deliverable even long after the snake bite, are needed. Traumatic or toxic degenerations of peripheral motor neurons cause a neuroparalysis that activates a pro-regenerative intercellular signaling program taking place at the neuromuscular junction (NMJ). We recently reported that the intercellular signaling axis melatonin-melatonin receptor 1 (MT1) plays a major role in the recovery of function of the NMJs after degeneration of motor axon terminals caused by massive Ca2+ influx. Here we show that the small chemical MT1 agonists: Ramelteon and Agomelatine, already licensed for the treatment of insomnia and depression, respectively, are strong promoters of the neuroregeneration after paralysis induced by krait venoms in mice, which is also Ca2+ mediated. The venom from a Bungarus species representative of the large class of neurotoxic snakes (including taipans, coral snakes, some Alpine vipers in addition to other kraits) was chosen. The functional recovery of the NMJ was demonstrated using electrophysiological, imaging and lung ventilation detection methods. According to the present results, we propose that Ramelteon and Agomelatine should be tested in human patients bitten by neurotoxic snakes acting presynaptically to promote their recovery of health. Noticeably, these drugs are commercially available, safe, non-expensive, have a long bench life and can be administered long after a snakebite even in places far away from health facilities.


Assuntos
Antivenenos , Indenos , Mordeduras de Serpentes , Humanos , Camundongos , Animais , Antivenenos/uso terapêutico , Mordeduras de Serpentes/complicações , Mordeduras de Serpentes/tratamento farmacológico , Receptores de Melatonina/uso terapêutico , Venenos de Serpentes , Recuperação de Função Fisiológica , Cálcio , Serpentes , Bungarus
18.
Sci Rep ; 14(1): 2567, 2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38296989

RESUMO

Bothrops and Lachesis are two of Brazil's medically most relevant snake genera, causing tens of thousands of bites annually. Fortunately, Brazil has good accessibility to high-quality antivenoms at the genus and inter-genus level, enabling the treatment of many of these envenomings. However, the optimal use of these treatments requires that the snake species responsible for the bite is determined. Currently, physicians use a syndromic approach to diagnose snakebite, which can be difficult for medical personnel with limited training in clinical snakebite management. In this work, we have developed a novel monoclonal antibody-based multiplex lateral flow assay for differentiating Bothrops and Lachesis venoms within 15 min. The test can be read by the naked eye or (semi)-quantitatively by a smartphone supported by a 3D-printed attachment for controlling lighting conditions. The LFA can detect Bothrops and Lachesis venoms in spiked plasma and urine matrices at concentrations spanning six orders of magnitude. The LFA has detection limits of 10-50 ng/mL in spiked plasma and urine, and 50-500 ng/mL in spiked sera, for B. atrox and L. muta venoms. This test could potentially support medical personnel in correctly diagnosing snakebite envenomings at the point-of-care in Brazil, which may help improve patient outcomes and save lives.


Assuntos
Bothrops , Venenos de Crotalídeos , Mordeduras de Serpentes , Animais , Humanos , Mordeduras de Serpentes/tratamento farmacológico , Venenos de Serpentes/uso terapêutico , Antivenenos/uso terapêutico , Venenos de Crotalídeos/uso terapêutico , Anticorpos Monoclonais/uso terapêutico
19.
Am J Trop Med Hyg ; 110(3): 609-617, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38295421

RESUMO

The Malayan pit viper (MPV: Calloselasma rhodostoma) is a medically important venomous snake causing numerous envenomations in Thailand. Administration of specific snake antivenom is the only effective treatment for MPV-envenomed patients. However, inappropriate administration or misuse of snake antivenom is problematic in some remote areas of tropical countries where the snakebite envenoming rate is notable. Currently, the indications for administration of MPV antivenom are focused mainly on hematological factors. These include 1) venous clotting time > 20 min, 2) unclotted 20-minute whole-blood clotting time, 3) international normalized ratio > 1.2, 4) platelet count < 50 × 103/µL, 5) systemic bleeding, and 6) impending compartment syndrome. We aimed to determine the association between laboratory data and antivenom administration in MPV-envenomed patients. A retrospective study of data from 2016 to 2021 in Narathiwat Province, the southernmost province in Thailand, was conducted. A total of 838 MPV-bitten patients were included in this study. Local effects and systemic effects were observed in 58.8% and 27.7% of patients, respectively. Coagulopathies, which range from abnormal blood clotting to systemic bleeding, represented the majority of systemic effects. Acute kidney injury developed in 2.5% of patients. In this study, 57.3% of patients were considered appropriate antivenom recipients. Interestingly, the present study revealed that local bleeding and mild to moderate thrombocytopenia became the independent factors for inappropriate use of MPV antivenom. Reeducation and supervision regarding the rational use of snake antivenom are needed to minimize the misuse of antivenom.


Assuntos
Antivenenos , Crotalinae , Mordeduras de Serpentes , 60573 , Humanos , Antivenenos/uso terapêutico , Estudos Retrospectivos , Laboratórios Clínicos , Tailândia , Mordeduras de Serpentes/tratamento farmacológico
20.
PLoS Negl Trop Dis ; 18(1): e0011921, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38241387

RESUMO

BACKGROUND: Currently, antivenoms are the only specific treatment available for snakebite envenoming. In Brazil, over 30% of patients cannot access antivenom within its critical care window. Researchers have therefore proposed decentralizing to community health centers to decrease time-to-care and improve morbidity and mortality. Currently, there is no evidence-based method to evaluate the capacity of health units for antivenom treatment, nor what the absolute minimum supplies and staff are necessary for safe and effective antivenom administration and clinical management. METHODS: This study utilized a modified-Delphi approach to develop and validate a checklist to evaluate the minimum requirements for health units to adequately treat snakebite envenoming in the Amazon region of Brazil. The modified-Delphi approach consisted of four rounds: 1) iterative development of preliminary checklist by expert steering committee; 2) controlled feedback on preliminary checklist via expert judge survey; 3) two-phase nominal group technique with new expert judges to resolve pending items; and 4) checklist finalization and closing criteria by expert steering committee. The measure of agreement selected for this study was percent agreement defined a priori as ≥75%. RESULTS: A valid, reliable, and feasible checklist was developed. The development process highlighted three key findings: (1) the definition of community health centers and its list of essential items by expert judges is consistent with the Brazilian Ministry of Health, WHO snakebite strategic plan, and a general snakebite capacity guideline in India (internal validity), (2) the list of essential items for antivenom administration and clinical management is feasible and aligns with the literature regarding clinical care (reliability), and (3) engagement of local experts is critical to developing and implementing an antivenom decentralization strategy (feasibility). CONCLUSION: This study joins an international set of evidence advocating for decentralization, adding value in its definition of essential care items; identification of training needs across the care continuum; and demonstration of the validity, reliability, and feasibility provided by engaging local experts. Specific to Brazil, further added value comes in the potential use of the checklist for health unit accreditation as well as its applications to logistics and resource distribution. Future research priorities should apply this checklist to health units in the Amazon region of Brazil to determine which community health centers are or could be capable of receiving antivenom and translate this expert-driven checklist and approach to snakebite care in other settings or other diseases in low-resource settings.


Assuntos
Antivenenos , Mordeduras de Serpentes , Humanos , Antivenenos/uso terapêutico , Mordeduras de Serpentes/tratamento farmacológico , Brasil , Lista de Checagem , Reprodutibilidade dos Testes
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