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Snakebite envenomings most frequently reported in Colombia are caused by snakes of the genera Bothrops, Bothriechis, Bothrocophias, and Porthidium. Their venoms induce local and systemic pathophysiological effects, sometimes leading to permanent sequelae such as reduced mobility of the limbs, amputations, besides the risk of death. The genus Bothrocophias includes nine species, among which B. campbelli has a distribution restricted to the department of Nariño in Colombia. In this work we determined the toxinological profile its venom, by performing assays for the lethal, hemorrhagic, edematogenic, and myotoxic activities in mouse models, as well as for in vitro coagulant activity on human plasma. The lethal toxicity of the venom was 142.7 µg venom/mouse (111.4-179.8 µg/mouse; 6.6-10.6 µg/g body weight) by intraperitoneal route. Its hemorrhagic activity (minimum hemorrhagic dose: 12.7 ± 2.3 µg) is generally weaker compared to other South American vipers, but edematogenic (minimum edematogenic dose 1.0 ± 0.3 µg), and myotoxic (minimum myotoxic dose 3.9 ± 2.5 µg) activities are very potent. Histopathological examination of the injected mouse gastrocnemius muscle showed prominent disorganization of the myofibrils, myonecrosis, and an intense inflammatory leukocyte infiltrate. In vitro, the minimal coagulant dose was 12.3 ± 0.5 µg. Overall, this toxinological profile would predict that the clinical picture of envenomings by B. campbelli might be characterized by moderate disturbances in the coagulation cascade, mild local hemorrhage, and, conversely, severe myonecrosis and edema, which could potentially lead to compartment syndrome and gangrene.

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Aryl Hydrocarbon Receptor (AHR) signaling is crucial for regulating the biotransformation of xenobiotics and physiological processes like inflammation and immunity. Meanwhile, Thalassophryne nattereri Peptide (TnP), a promising anti-inflammatory candidate from toadfish venom, demonstrates therapeutic effects through immunomodulation. However, its influence on AHR signaling remains unexplored. This study aimed to elucidate TnP’s molecular mechanisms on the AHR–cytochrome P450, family 1 (CYP1) pathway upon injury-induced inflammation in wild-type (WT) and Ahr2-knockdown (KD) zebrafish larvae through transcriptomic analysis and Cyp1a reporters. TnP, while unable to directly activate AHR, potentiated AHR activation by the high-affinity ligand 6-Formylindolo [3,2-b]carbazole (FICZ), implying a role as a CYP1A inhibitor, confirmed by in vitro studies. This interplay suggests TnP’s ability to modulate the AHR-CYP1 complex, prompting investigations into its influence on biotransformation pathways and injury-induced inflammation. Here, the inflammation model alone resulted in a significant response on the transcriptome, with most differentially expressed genes (DEGs) being upregulated across the groups. Ahr2-KD resulted in an overall greater number of DEGs, as did treatment with the higher dose of TnP in both WT and KD embryos. Genes related to oxidative stress and inflammatory response were the most apparent under inflamed conditions for both WT and KD groups, e.g., Tnfrsf1a, Irf1b, and Mmp9. TnP, specifically, induces the expression of Hspa5, Hsp90aa1.2, Cxcr3.3, and Mpeg1.2. Overall, this study suggests an interplay between TnP and the AHR-CYP1 pathway, stressing the inflammatory modulation through AHR-dependent mechanisms. Altogether, these results may offer new avenues in novel therapeutic strategies, such as based on natural bioactive molecules, harnessing AHR modulation for targeted and sustained drug effects in inflammatory conditions.

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Snake venom serine proteases (SVSPs) are chymotrypsin-like proteins found in some venoms of the Viperidae family. These enzymes affect physiological processes of their prey and victims, acting mainly in the hemostatic, fibrinolytic and kinin systems. SVSPs belong to the PA clan, PA (S) subclan, S1 family and A subfamily of proteolytic enzymes. This work, describes a SVSP (Lmr-PA) isolated from the venom of Lachesis muta rhombeata which activates plasminogen. The proteinase was purified by combination of gel filtration and anionic exchange chromatographies. Its homogeneity was demonstrated by SDS-PAGE, reverse-phase HPLC, and two-dimensional electrophoresis. Lmr-PA is a 30-kDa single chain glycoprotein. Its amino acid sequence (61%) was determined by mass spectrometry on nLC-MS/MS. Lmr-PA activates plasminogen to release plasmin and degrades the plasmin substrate S-2251 as well as dimethylcasein. PMSF, the specific inhibitor of serine proteases completely blocked Lmr-PA activity. The proteinase cleaves the Aα chain and partially the Bβ and γ chains of fibrinogen. In addition the protease degrades laminin, nidogen and type IV collagen from Matrigel. The enzyme digests fibrin in presence of plasminogen in vitro. Deglycosylated Lmr-PA loses approximately 26% of its activity. In addition, Lmr-PA activity is inhibited by α2-macroglobulin at a ratio of 2:1 (α2-M:E) and α2-antiplasmin inhibits plasmin generated from plasminogen. Lmr-PA does not induce aggregation of washed human platelets but, aggregates platelets in presence of exogenous fibrinogen and binds to the platelet receptors glycoproteins (GP) GPIb and GPVI. Our data indicate that Lmr-PA is a plasminogen activating serine protease, like to previously reported LV-PA from Lachesis muta muta venom. These results suggested that Lmr- PA play a role in the pathology of snake envenomation and could be a useful model to study hemostatic disorders caused by snake bites.

As serinoproteases do veneno de serpentes (SVSPs) são proteínas semelhantes à quimotripsina presentes encontradas em alguns venenos da família Viperidae. Essas enzimas afetam os processos fisiológicos de suas presas e vítimas, atuando principalmente nos sistemas hemostático, fibrinolítico e cinina. As SVSPs pertencem ao clã PA, subclan PA (S), família S1 e subfamília A de enzimas proteolíticas. Este trabalho descreve uma SVSP (Lmr-PA) isolada do veneno de Lachesis muta rhombeata que ativa o plasminogênio. A proteinase foi purifica por combinação de cromatografias de filtração em gel e troca aniônica. Sua homogeneidade foi demonstrada por SDS-PAGE, HPLC de fase reversa e eletroforese bidimensional. Lmr-PA é uma glicoproteína de cadeia simples de 30 kDa. A sua sequência de aminoácidos (61%) foi determinada por espectrometria de massa em nLC-MS/MS. Lmr-PA ativa o plasminogênio para liberar plasmina e degrada o substrato de plasmina S-2251, bem como a dimetilcaseína. PMSF, um inibidor específico de serinoproteases bloqueou completamente a atividade da Lmr-PA. A proteinase cliva a cadeia Aα e parcialmente as cadeias Bβ e γ do fibrinogênio. Além disso, a protease degrada laminina, nidogênio e colágeno tipo IV de Matrigel. A enzima digere a fibrina na presença de plasminogênio in vitro. Lmr-PA desglicosilada perde aproximadamente 26% da sua atividade. Além disso, a atividade da Lmr-PA é inibida pela α2-macroglobulina em uma proporção de 2:1 (α2-M:E) e a α2-antiplasmina inibe a plasmina gerada a partir do plasminogênio. Lmr-PA não induz a agregação de plaquetas humanas lavadas, mas agrega plaquetas na presença de fibrinogênio exógeno e se liga às glicoproteínas dos receptores plaquetários (GP) GPIb e GPVI. Nossos dados indicam que a Lmr-PA é uma serinoprotease ativadora do plasminogênio semelhante a LV-PA relatada anteriormente do veneno de Lachesis muta muta. Esses resultados sugerem que a Lmr-PA desempenha um papel na patologia do envenenamento por serpentes e pode ser um modelo útil para estudar distúrbios hemostáticos causados por acidentes ofídicos.

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TmC4-47.2 is a toxin with myotoxic activity found in the venom of Thalassophryne maculosa, a venomous fish commonly found in Latin America whose envenomation produces an injury characterized by delayed neutrophil migration, production of major pro-inflammatory cytokines, and necrosis at the wound site, as well as a specific systemic immune response. However, there are few studies on the protein structure and functions associated with it. Here, the toxin was identified from the crude venom by chromatography and protein purification systems. TmC4-47.2 shows high homology with the Nattectin from Thalassophryne nattereri venom, with 6 cysteines and QPD domain for binding to galactose. We confirm its hemagglutinating and microbicide abilities independent of carbohydrate binding, supporting its classification as a nattectin-like lectin. After performing the characterization of TmC4-47.2, we verified its ability to induce an increase in the rolling and adherence of leukocytes in cremaster post-capillary venules dependent on the α5ß1 integrin. Finally, we could observe the inflammatory activity of TmC4-47.2 through the production of IL-6 and eotaxin in the peritoneal cavity with sustained recruitment of eosinophils and neutrophils up to 24 h. Together, our study characterized a nattectin-like protein from T. maculosa, pointing to its role as a molecule involved in the carbohydrate-independent agglutination response and modulation of eosinophilic and neutrophilic inflammation.

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TmC4-47.2 is a toxin with myotoxic activity found in the venom of Thalassophryne maculosa, a venomous fish commonly found in Latin America whose envenomation produces an injury characterized by delayed neutrophil migration, production of major pro-inflammatory cytokines, and necrosis at the wound site, as well as a specific systemic immune response. However, there are few studies on the protein structure and functions associated with it. Here, the toxin was identified from the crude venom by chromatography and protein purification systems. TmC4-47.2 shows high homology with the Nattectin from Thalassophryne nattereri venom, with 6 cysteines and QPD domain for binding to galactose. We confirm its hemagglutinating and microbicide abilities independent of carbohydrate binding, supporting its classification as a nattectin-like lectin. After performing the characterization of TmC4-47.2, we verified its ability to induce an increase in the rolling and adherence of leukocytes in cremaster post-capillary venules dependent on the α5β1 integrin. Finally, we could observe the inflammatory activity of TmC4-47.2 through the production of IL-6 and eotaxin in the peritoneal cavity with sustained recruitment of eosinophils and neutrophils up to 24 h. Together, our study characterized a nattectin-like protein from T. maculosa, pointing to its role as a molecule involved in the carbohydrate-independent agglutination response and modulation of eosinophilic and neutrophilic inflammation.

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The secretions of the Giant Monkey Frog Phyllomedusa bicolor are used by populations in the Amazon regions (mainly the indigenous Katukinas and Kaxinawás). The so-called "toad vaccine" or "kambô" is applied as a medication for infections and to prevent diseases, and also as physical and mental invigorator, and analgesic. Since the 1980s, researchers and companies have been interested in the composition of these secretions. Phyllomedusin, phyllokinin, caerulein and sauvagine are the polypeptides in these secretions that can cause intense effects on smooth muscles, vessels provoking, nausea and vomiting, arterial hypotension, flushing, palpitations, nausea, vomiting, bile secretion and angioedema. These actions are similar to bradykinin. However, the feeling of well-being and improvement of motor skills described by the users seems to be associated with dermorphine, caerulein or deltorphin - peptides with analgesic properties - and their affinity for the opiate receptor systems. Caerulein is a peptide that increases digestive secretions. Phyllomedusin and Phyllokinin lead to blood pressure and digestive effects. Sauvagine release corticotropin and mimics the physiological reactions of exposure to stress. Deltorphins and dermorphins have high affinity for the opiate receptor system and can lead to analgesia. The fame acquired by the therapy motivated the use by individuals from urban areas worldwide, without safety considerations. While in indigenous communities, there is an entire cultural tradition that provides relative safety to the application, however, the extension of use to individuals from urban areas worldwide is a problem, with reports of severe adverse effects and deaths. Undoubtedly, the skin secretions of the Phyllomedusa genus contain substances of intense pharmacological action and that can lead to research for therapeutic uses, but control over their application in rituals outside the forest is needed due the risks presented.

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Background: Toxinology is a sub-field of toxicology dedicated to studying toxins produced by animals, plants and, microorganisms. In Colombia, during the last thirty years, this area has been mainly investigated by Ophidism/Scorpionism Program of Universidad de Antioquia. However, some other research groups have also contributed to our knowledge of venoms and toxins, as well as their related effects and treatments. Objective: to highlight the most significant findings in toxinology made by the Ophidism/Scorpionism Program and other research groups in Colombia. Methods: 119 papers dealing with the history of ophidiology and toxinology in Colombia were collected and analyzed. Results: some useful terms are described to understand toxinology and its scope. Also, a brief history of ophidiology is presented, spanning from the discovery of America until present-day findings. Finally, an overall description of several results related to toxin isolation, characterization, antivenoms, clinical trials, description of new species, proteomic and transcriptomic, among others. The nineteens were characterized by the study of snakebites, their clinic manifestations, and the use of antivenoms. In addition, the ethnopharmacological studies of medicinal plants used in snakebite treatments began to be explored. The 2000s included the newly ethnopharmacology, toxin isolation, clinical trials, inhibitor studies, scorpion venom characterization, and scorpion stings features. Finally, from 2010 until today, proteomic and transcriptomic gave the most important findings. Conclusions: Toxinology works in Colombia have contributed to our knowledge about endemic species, clinical manifestations of snakebite and scorpion stings, and the development of new therapeutic agents. However, we invite Colciencias and other funding agencies to assign more resources to support a higher number of researchers in this field, since snakebite is considered a neglected tropical disease by the World Health Organization, which needs more attention from governments and scholars. Finally, the venoms of some species and their possible mode of action are still unknown to us. Besides, given the complexity of venoms, we are not yet aware of the potential use of toxins in current biomedicine. Thus, studies in toxinology must continue.

Antecedentes: La Toxinología es el campo de la Toxicología que estudia las toxinas producidas por animales, plantas y microorganismos. En Colombia, durante los últimos treinta años, los estudios realizados en esta área han sido desarrollados principalmente por el Programa de Ofidismo/Escorpionismo de la Universidad de Antioquia. Sin embargo, otros grupos de investigación también han contribuido en el conocimiento de venenos, toxinas, efectos y tratamientos. Objetivo: Destacar los hallazgos más relevantes en toxinología realizados por el Programa de Ofidismo Escorpionismo y otros grupos de investigación en Colombia. Métodos: Se recopilaron 119 artículos referentes a la historia de la ofidiología y la toxinología en Colombia. Resultados: Se describieron algunos términos útiles para el entendimiento de la toxinología y sus alcances. Se construyó una breve historia de la ofidiología que inicia con el descubrimiento de América y finaliza con hallazgos recientes. Se realizó una amplia descripción de varios resultados relacionados con el aislamiento y caracterización de toxinas, antivenenos, ensayos clínicos, descripciones de nuevas especies, proteómica y transcriptómica, entre otras. Así, la década de los noventa se caracterizó por el estudio de las mordeduras de serpientes, sus manifestaciones clínicas, el uso de antivenenos y la exploración de la etnofarmacología asociada a las mordeduras de serpiente. La década del 2000 incluyó nuevamente etnofarmacología, el aislamiento de toxinas, ensayos clínicos, estudios sobre inhibidores de toxinas, caracterización de venenos y picaduras de escorpión. Finalmente, desde 2010 hasta hoy, la proteómica y transcriptómica aportaron los hallazgos más importantes. Conclusiones: Los estudios de Toxinología en Colombia han contribuido al conocimiento de especies endémicas, manifestaciones clínicas de mordeduras de serpientes y picaduras escorpiones, y el desarrollo de nuevos agentes terapéuticos. No obstante, se invita a Colciencias y a otras agencias de financiamiento a apoyar la investigación en este campo, ya que es considerada una enfermedad tropical desatendida por la Organización Mundial de la Salud y necesita mayor atención por parte del gobierno e instituciones académicas. Además, dada la complejidad de los venenos, se desconoce el uso potencial de las toxinas en la biomedicina actual. Así, se deben continuar realizando estudios en toxinología.

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Animal poisons are glandular secretions that compromise biological systems. Their active biomolecules are called toxins. Many affect ion channels and ionotropic receptors, membrane proteins that control cellular ion flow. In this work a bibliographic survey was carried out about the main toxins of animal origin whose targets are ion channels. The groups with the highest toxin diversity were Conus ssp., Araneae, Scorpiones, Serpentes and Cnidaria. Toxins studies support basic and applied science. Despite their therapeutic potential, of all the studied poisons only ω-conotoxin MVIIA was approved for clinical use. So the field still has a lot to offer.

Venenos animais são secreções glandulares que comprometem sistemas biológicos. Suas biomoléculas ativas são denominadas toxinas. Muitas afetam canais iônicos e receptores ionotrópicos, proteínas de membrana que controlam o fluxo iônico celular. Neste trabalho foi realizado um levantamento bibliográfico sobre as principais toxinas de origem animal cujos alvos são canais iônicos. Os grupos com maior diversidade de toxinas foram Conus ssp., Araneae, Scorpiones, Serpentes e Cnidaria. Estudos sobre toxinas auxiliam a ciência de base e aplicada. Apesar do potencial terapêutico, dentre todos os venenos estudados apenas a ω-conotoxina MVIIA obteve aprovação para o uso clinico. Portanto, o campo ainda tem muito a oferecer.

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The present study analyzes cases of scorpionism in 11 dogs and a cat that were registered at a veterinary clinic in the city of Manizales, between 2009 and 2018. All eight cases where expert identification of the arthropod was possible, involved Centruroides gracilis (Latreille, 1804). None of the stings were lethal, though two cases were classified as severe envenomation and five moderate. The primary sign was local pain, in addition to lameness in all 10 cases that involved one of the limbs (83,3%, 10 of 12 cases). The other two cases had injuries involving the face. The established treatment was symptomatic with clinical and patient monitoring. Antivenom could not be used due to its high cost and scarcity. However, even the severest cases improved satisfactorily, and all patients were discharged without complication.

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Objetivo: Describir el comportamiento del accidente ofídico en el departamento de Sucre. Métodos: Se realizó un estudio descriptivo y retrospectivo, en el cual se analizaron 803 reportes de accidentes ofídicos notificados al sistema de vigilancia epidemiologia del departamento de Sucre, durante los años 2007 a 2012, la información fue suministrada por la dirección de salud pública de la secretaria de salud del departamento de Sucre, en formato Excel©, descargada directamente del aplicativo SIVIGILA. Los datos obtenidos se analizaron estadísticamente empleando medidas de tendencia central. Resultados: En el 48.2% de los casos, el género Bothrops se identificó como el agente agresor y en el 83.9% de los casos la mordedura se localizó en las extremidades del paciente. En 356 casos equivalentes al 44% el paciente no fue hospitalizado o no se consignó esta información en la ficha. En el tratamiento de los casos hospitalizados se empleó un promedio de 4.3 ± 4.5 viales por paciente; estos datos son consistentes con el protocolo para casos leves registrados (n=450), pero al revisar los casos individuales se encontró que 228 pacientes solo recibieron entre 1 y 3 ampollas. En 84 casos solo se administró un vial.

Objective: Describe the behavior of ophidic accident in the department of Sucre. Methods: A descriptive, retrospective study was done from 2007 to 2012, in this study, 803 cases of snakebites were reported to the surveillance system of the epidemiology department of Sucre. In this department, the snakebite accidents occurs along the entire year, mainly affecting men 15 to 44 years. Those affected come from all municipalities in the department and around the rural area, and it is mainly engaged in agriculture and domestic work; however, the town of Sincelejo accounts for 28.8% of all notifications. Results: In 48.2% of cases, the genus Bothrops was identified as the offending agent and in 83.9% of cases, the bite was found in the patient's limbs. In 356 cases or 44% the patients were hospitalized or the information of this records were not found. The treatment of hospitalized cases averaged 4.3 ± 4.5 shots were used per patient; This data is consistent with the protocol for registered mild cases (n = 450), but reviewing individual cases; then, it was found that 228 patients received only 1 to 3 ampoules. In 84 cases only one shot was administered.

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CONTEXT: Therapy for snakebites relies on the application of antivenoms, which may be produced with different immunogenic mixtures of venom and possess different pharmaceutical characteristics. For these reasons, immunological cross-reactivity and heterologous neutralization were analyzed relative to the protein content of three antivenoms used in the Americas. METHODS: The antivenoms studied were composed of equine F(ab')2 fragments from animals immunized with Crotalinae venoms. The antivenoms were tested against venoms of seven pit viper species from Argentina, seven from Mexico, one from Costa Rica, and one from Colombia. RESULTS: Immunoblotting showed high cross-reactivity of all major protein bands with all the antivenoms tested. ELISA results also showed high cross-reactivity among the different venoms and antivenoms, and a high heterologous neutralization was observed. The results can be interpreted in different ways depending on whether the reactivity is considered in terms of the volume of antivenom used or by the amount of protein contained in this volume of antivenom. The antivenoms with high immunochemical reactivity and neutralizing capacity were those with higher protein content per vial; but when doses were adjusted by protein content, antivenoms of apparently lower neutralizing capacity and immunochemical reactivity showed at least similar potency and reactivity although volumetrically at higher doses. CONCLUSION: Protein content relative to neutralization potency of different products must be taken into account when antivenoms are compared, in addition to the volume required for therapeutic effect. These results show the importance of obtaining high-affinity and high-avidity antibodies to achieve good neutralization using low protein concentration and low-volume antivenoms.

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Renal dysfunction is an important aggravating factor in accidents caused by Crotalus durissus terrificus (Cdt) and Bothrops jararaca (Bj) bites. N-acetyl-l-cysteine (NAC) is well known as a nephroprotective antioxidant with low toxicity. The present study investigated the effects of NAC on redox status and markers of renal function in mice that received vehicle (controls) or venoms (v) of Cdt and Bj. In controls NAC promoted hypercreatinemia, hypouremia, hyperosmolality with decreased urea in urine, hyperproteinuria, decreased protein and increased dipeptidyl peptidase IV (DPPIV) in membrane-bound fraction (MF) from renal cortex (RC) and medulla (RM). NAC ameliorated or normalized altered creatinuria, proteinemia and aminopeptidase (AP) acid in MF, AP basic (APB) in soluble fraction (SF), and neutral AP in SF and MF from RC and RM in vBj envenomation. NAC ameliorated or normalized altered neutral AP in SF from RC and RM, and DPPIV and protein in MF from RC in vCdt envenomation. NAC ameliorated or restored renal redox status respectively in vCdt and vBj, and normalized uricemia in both envenomations. These data are promising perspectives that recommend the clinical evaluation of NAC as potential coadjuvant in the anti venom serotherapy for accidents with these snake's genera.

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Introducción: El diseño de instrumentos o moléculas inspiradas en la naturaleza hapermitido avanzar en diferentes áreas de la ciencia y tecnología. Objetivo: Evaluarcambios plásticos a corto plazo desencadenados por la administración intraperitonealde un péptido agonista del receptor de glutamato NMDA. Materiales y métodos:Se utilizaron ratas macho divididas en grupo péptido (a quienes se administróperitonealmente el péptido) y grupo control (a quienes se administró peritonealmenteel vehículo). Por técnicas de estereotaxia se localizaron electrodos de estimulacióny registro en las áreas hipocampales CA3 y CA1 respectivamente, con el ánimo deobtener los potenciales de campo y analizar cambios en su pendiente y amplitud porla aplicación de pares de estímulos, antes y después de la administración del péptido.Resultados: Aunque con la administración del péptido no hay cambios en variablessistémicas como la temperatura o la frecuencia cardiaca, sí se pueden modificar lospotenciales de campo, específicamente cuando el intervalo entre pares de estímuloses más corto (40 a 80 ms). Conclusión: El péptido evaluado en el presente trabajotiene efectos en la facilitación por pulsos pareados tanto en la amplitud como en lapendiente de potenciales de campo en el hipocampo de ratas, pero en los intervalosentre estímulos más cortos...

Introduction: Designing bio-inspired devicesor molecules has been a longstanding methodsupporting multiple advances in science and technology.Objective: To test the potential effectof intraperitoneal administration of the bio-inspiredpeptide on short-term plasticity. Materialsand methods: Male rats in two groups (peptidetreated and control) were used for registrationof hippocampal field potentials from CA1, afterpaired stimuli in CA3 contra lateral area. Results:Amplitude and slope of field potentials’,both before and after peptide administration,showed no changes in systemic factors (temperatureand heart rate), but statistical significancein short term plasticity in small inter stimuli interval(40 to 80 ms). Conclusion: The current researchshows effects on paired pulse facilitationcaused by peptide treatment, specifically on interstimuli interval shorter...

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Acute renal failure (ARF) is one of the most serious complications of envenoming by Crotalus durissus terrificus bites. The present study investigates the effects of n-acetil-Lcisteína (NAC), allopurinol and probenecid on classical parameters of renal function and renal oxidative stress, as well as the effects of NAC on renal aminopeptidase activities, in the kidney of mice inoculated with C. d. terrificus venom (vCdt). The treatment of envenomed mice with NAC ameliorates the content of protein in the membrane-bound fraction of renal cortex and the activity levels of soluble neutral aminopeptidase in the renal cortex and medulla, and of dipeptidyl peptidase IV in the membrane-bound fraction of the renal cortex. In addition, NAC mitigates the uricemia and the renal oxidative imbalance, two marked features of the nephrotoxic effect of vCdt. Increased uricemia and oxidative stress induced by this venom are also ameliorated by allopurinol and probenecid. However, among these three agents under study only the allopurinol significantly reduces the lethality of vCdt. The effectiveness of probenecid would be compromised by hypercreatinemia, hypocreatinuria and worsening of the urinary hypo-osmolality caused by this drug in envenomed mice. In turn, the highest effectiveness of allopurinol seems to be due to its high ability to decrease the intracellular levels of uric acid and/or to block xanthine oxidase-associated oxidants. Data provide consistent evidences linking uric acid, oxidative stress and ARF induced by C. d. terrificus venom, showing that this envenoming constitutes an attractive animal model suitable for studying the hyperuricemia and that the allopurinol deserves to be clinically evaluated as an approach complementary to anti-snake venom serotherapy.

A insuficiência renal aguda (IRA) é uma das complicações mais graves resultantes do envenenamento por Crotalus durissus terrificus. O presente estudo investiga os efeitos da nacetil-L-cisteína (NAC), do alopurinol e do probenecid nos parâmetros clássicos da função renal, estresse oxidativo renal e, no caso da NAC, também sobre atividades aminopeptidásicas renais, em camundongos inoculados com veneno de C. d. terrificus (vCdt). O tratamento do envenenamento por vCdt com a NAC melhora o teor de proteína da fração de membrana do córtex renal e as atividades de aminopeptidase neutra solúvel no córtex e medula renais e de dipeptidil peptidase IV da fração de membrana do córtex renal. Além disso, a NAC melhora a uricemia e o desequilíbrio oxidativo renal, duas características marcantes do efeito nefrotóxico do vCdt. O aumento da uricemia e estresse oxidativo induzido por esse veneno também é amenizado por alopurinol e probenecid. Porém, dentre esses três agentes avaliados somente o alopurinol reduz significativamente a letalidade do vCdt. A eficácia do probenecid estaria comprometida porque este fármaco também produz hipercreatinemia, hipocreatinúria e piora a hipo-osmolalidade urinária nos camundongos envenenados. Por sua vez, a maior eficácia do alopurinol parece ser consequência de sua maior capacidade em diminuir os níveis intracelulares de ácido úrico e/ou por sua habilidade de bloquear oxidantes associados à xantina oxidase. Esses dados fornecem evidências consistentes da ligação entre ácido úrico, estresse oxidativo e a IRA induzida por veneno de C. d. terrificus, mostrando que esse envenenamento constitui um interessante modelo animal para o estudo da IRA associada à hiperuricemia e que o alopurinol merece ser avaliado clinicamente como uma abordagem complementar à soroterapia anti-veneno de serpente.

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Few papers have been published on snake bites caused by Philodryas olfersii. We report here the first case identified at the Centro de Assistência Toxicológica do Hospital da Restauração, Recife, State of Pernambuco. This case was described based on medical protocols, interviewing the patient and identifying the animal that caused the bite. The patient presented pain, heat, erythema, edema and ecchymosis, without other laboratory abnormalities or coagulation disorders. The treatment consisted of administration of eight ampoules of antibothropic serum, and post-administration allergenic reactions were observed. The importance of bites by opistoglyph snakes needs to be reconsidered in research and at specialized treatment centers.

Existem poucas publicações de acidentes ofídicos causados pela espécie Philodryas olfersii. Relatamos aqui o primeiro caso identificado no Centro de Assistência Toxicológica do Hospital da Restauração, Recife, Estado de Pernambuco. A descrição do caso foi realizada com base nos protocolos médicos, entrevista com o paciente e identificação do animal causador do acidente. O paciente apresentou dor, calor, eritema, edema e equimose, sem outras alterações laboratoriais ou distúrbios da coagulação. O tratamento executado mediante a administração de oito ampolas de soro antibotrópico apresentou reações alergênicas pós-administração. A relevância dos acidentes por serpentes opistóglifas deve ser reconsiderada na pesquisa e nos centros de tratamento especializados.

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Crotalus durissus terrificus envenomation has been associated with direct nephrotoxicity, rhabdomyolysis, hyperuricemia, urinary hypoosmolality, alterations in aminopeptidaseactivities (AP) and oxidative stress. This study evaluated the effects of lipoic acid (LA) on renal function, lethality, AP and GSSG/GSH in mice injected with C. d. terrificus venom (vCdt). The doses and routes of administration of LA and vCdt promoted no systemic myotoxicity. LA did not alter significantly the lethality of vCdt. In nonenvenomed, LA induced hypercreatinemia, urinary hyperosmolality, decrease of urinary urea and creatinine, increase of protein in plasma and in soluble fraction (SF) and decrease in membraneboundfraction (MF) of cortex and medulla. Decreased levels of all AP (except neutral-AP in MF-medulla) were also induced by LA in nonenvenomed. LA associated with vCdt decreased plasma osmolality, hematocrit, urinary uric acid, but increased urinary and SF-medullar protein. LA mitigated the increase of protein in SF-cortex and corrected hyperuricemia, GSSG/GSH and protein in MF-cortex and MF-medulla, as well as decreased plasma neutral AP and acid AP in MF-medulla of envenomed mice. Data suggest that LA contributes to the solubilization/remotion of proteins in MF with impairment of most AP,but it could be beneficial for the treatment of the direct nephrotoxicity of vCdt.

Assuntos

RESUMO

The phospholipase A2 superfamily encompasses 15 groups that are classified into: secreted PLA2 (sPLA2); cytosolic PLA2 (cPLA2); Ca2+-independent intracellular PLA2 (iPLA2); platelet-activating factor acetylhydrolase (PAF-AH); and lysosomal PLA2. Currently, approximately 700 PLA2 sequences are known, of which 200 are obtained from the venom gland of Crotalinae snakes. However, thus far, little information is available on cloning, purification and structural characterization of PLA2 from Crotalus durisssus cascavela venom gland. In the present work, we report the molecular cloning of a novel svPLA2 from C. d. cascavella (Cdc), a predominant rattlesnake subspecies in northeastern Brazil. The Cdc svPLA2 cDNA precursor is 689 nucleotides long and encodes a protein of 138 amino acid residues, with a calculated molecular mass of approximately 13,847 Da and an estimated isoelectric point of 5.14. Phylogenetic analysis of Crotalinae PLA2 reveals that Cdc PLA2 clustered with other acidic type IIA PLA2 homologues is also present in the venom of North American rattlesnakes. Hitherto, this study presents a novel PLA2 cDNA precursor from C. d. cascavella and data reported herein will be useful for further steps in svPLA2 purification and analysis.(AU)

Assuntos

RESUMO

The phospholipase A2 superfamily encompasses 15 groups that are classified into: secreted PLA2 (sPLA2); cytosolic PLA2 (cPLA2); Ca2+-independent intracellular PLA2 (iPLA2); platelet-activating factor acetylhydrolase (PAF-AH); and lysosomal PLA2. Currently, approximately 700 PLA2 sequences are known, of which 200 are obtained from the venom gland of Crotalinae snakes. However, thus far, little information is available on cloning, purification and structural characterization of PLA2 from Crotalus durisssus cascavela venom gland. In the present work, we report the molecular cloning of a novel svPLA2 from C. d. cascavella (Cdc), a predominant rattlesnake subspecies in northeastern Brazil. The Cdc svPLA2 cDNA precursor is 689 nucleotides long and encodes a protein of 138 amino acid residues, with a calculated molecular mass of approximately 13,847 Da and an estimated isoelectric point of 5.14. Phylogenetic analysis of Crotalinae PLA2 reveals that Cdc PLA2 clustered with other acidic type IIA PLA2 homologues is also present in the venom of North American rattlesnakes. Hitherto, this study presents a novel PLA2 cDNA precursor from C. d. cascavella and data reported herein will be useful for further steps in svPLA2 purification and analysis.

Assuntos

RESUMO

This work succinctly describes the professional and scientific life of Dr. José R. Giglio, one of the most outstanding Brazilian researchers in the field of Toxinology. During his long and successful career, he has made major contributions, especially in elucidating the function, structure, and mechanisms of action of animal venom proteins (from snakes, scorpions and spiders) as well as the characterization of antibodies and several inhibitors of venoms and toxins. We present here a brief history of Dr. Giglios personal and professional life, also reporting some of his numerous published scientific articles on venoms from snakes (Bothrops, Crotalus, and other genera), scorpions (Tityus sp), spiders (Phoneutria sp), their isolated toxins and natural inhibitors. Thus, this work is a tribute to Dr. Giglio in his 73rd birthday, having devoted 48 years of his life studying animal venoms, an effort that has continued even after his formal retirement from university duties.