New records of helminth infections in Bothrops atrox Linnaeus, 1758 from Marajó Island-Brazil and a literature review with a check list of helminths infecting Bothrops species (Squamata, Viperidae) in the neotropical region.

Snakes of the genus Bothrops inhabit tropical forests in Central and South America and are important for the biomedical and pharmaceutical industries because of the chemical properties of their venom. They serve as either definitive or intermediate hosts for many parasitic helminths. The Marajó Island (Brazil) is the natural habitat of venomous snakes, Bothrops atrox and Bothrops marajoensis, which are often found around rural and peri-urban areas and are known to bite humans. Samples of helminths parasitizing the oral cavity, subcutaneous tissues, coelomic cavity, and intestine of four B. atrox from Marajó Island (Pará-Brazil) were collected. The specimens studied were taxonomically classified as trematodes of the species Stycholecitha serpentis, nematodes of the genera Eustrongylides and Camallanus and cystacanths of an acanthocephalan of the genus Centrorhynchus. The aims of the present study were: to record helminths found in B. atrox from the Marajó Island; to discuss their role as definitive, intermediate, or paratenic hosts; and to compile a list of helminths that have been recorded in snakes of the genus Bothrops of the Neotropical region.

Identification of purinergic system components in the venom of Bothrops mattogrossensis and the inhibitory effect of specioside extracted from Tabebuia aurea.

Snake bites are a severe problem in the countryside of Brazil and are usually attributed to snakes of the genera Bothrops, Crotalus, and Lachesis. Snake venom can release ectoenzymes and nucleotidases that modulate the purinergic system. In addition to serum therapy against snake poisoning, medicinal plants with anti-inflammatory activities, such as Tabebuia aurea, is empirically applied in accidents that occur in difficult-to-access areas. This study aimed was to verify the presence and activity of nucleotidases in the crude venom of Bothrops mattogrossensis (BmtV) in vitro and characterize the modulation of purinergic components, myeloid differentiation, and inflammatory/oxidative stress markers by BmtV in vivo and in vitro. Moreover, our study assessed the inhibitory activities of specioside, an iridoid isolated from Tabebuia aurea, against the effects of BmtV. Proteomic analysis of venom content and nucleotidase activity confirm the presence of ectonucleotidase-like enzymes in BmtV. In in vivo experiments, BmtV altered purinergic component expression (P2X7 receptor, CD39 and CD73), increased neutrophil numbers in peripheral blood, and elevated oxidative stress/inflammatory parameters such as lipid peroxidation and myeloperoxidase activity. BmtV also decreased viability and increased spreading index and phagocytic activity on macrophages. Specioside inhibited nucleotidase activity, restored neutrophil numbers, and mediate the oxidative/inflammatory effects produced by BmtV. We highlight the effects produced by BmtV in purinergic system components, myeloid differentiation, and inflammatory/oxidative stress parameters, while specioside reduced the main BmtV-dependent effects.

Long-term disability after cerebral ischemic stroke following a Bothrops atrox snakebite in the Brazilian Amazon.

Bothrops atrox envenomations in the Brazilian Amazon are responsible for a number of local and systemic effects. Among these, stroke presents the worst prognosis for the patient since it may evolve into disabilities and/or premature death. This complication is caused by coagulation disorders and generates hemorrhagic and thrombotic conditions. This study presents a case report of a 54-year-old female patient who presented extensive cerebral ischemia after a B. atrox envenomation that occurred in the state of Amazonas, Brazil. The patient was hospitalized for 102 days, which included a stay in the intensive care unit. Clinical and laboratory findings indicated a thrombogenic coagulopathy. On discharge, the patient had no verbal response, partial motor response, and right hemiplegia. The assessment carried out four years after discharge evidenced incapacitation, global aphasia and bilateral lower and upper limbs showed hypotrophy with a global decrease in strength. Ischemic stroke is a possible complication of B. atrox snakebites even after antivenom treatment, with the potential to cause debilitating long-term consequences.

Preclinical evaluation of single domain antibody efficacy in mitigating local tissue damage induced by Bothrops snake envenomation.

Camelid single-domain antibodies (VHH) represent a promising class of immunobiologicals for therapeutic applications due to their remarkable stability, specificity, and therapeutic potential. To enhance the effectiveness of antivenoms for snakebites, various methods have been explored to address limitations associated with serum therapy, particularly focusing on mitigating local damage and ensuring sustainable production. Our study aimed to characterize the pharmacological profile and neutralization capacity of anti-Phospholipase A2 (PLA2) monomeric VHH (Genbank accessions: KC329718). Using a post-envenoming mouse model, we used intravital microscopy to assess leukocyte influx, measured CK and LDH levels, and conducted a histopathology analysis to evaluate VHH KC329718's ability to neutralize myotoxic activity. Our findings demonstrated that VHH KC329718 exhibited heterogeneous distribution in muscle tissue. Treatment with VHH KC329718 reduced leukocyte influx caused by BthTX-I (a Lys-49 PLA2) by 28 %, as observed through intravital microscopy. When administered at a 1:10 ratio [venom or toxin:VHH (w/w)], VHH KC329718 significantly decreased myotoxicity, resulting in a 35-40 % reduction in CK levels from BthTX-I and BthTX-II (an Asp-49 PLA2) and a 60 % decrease in CK levels from B. jararacussu venom. LDH levels also showed reductions of 60%, 80%, and 60% induced by BthTX-I, BthTX-II, and B. jararacussu venom, respectively. Histological analysis confirmed the neutralization potential, displaying a significant reduction in tissue damage and inflammatory cell count in mice treated with VHH KC329718 post B. jararacussu venom inoculation. This study underscores the potential of monomeric anti-PLA2 VHH in mitigating myotoxic effects, suggesting a promising avenue for the development of new generation antivenoms to address current therapeutic limitations.

Alkaloids from Siparuna (Siparunaceae) are predicted as the inhibitors of proteolysis and plasma coagulation caused by snake venom and potentially counteract phospholipase A2 activity of Bothrops jararaca.

ETHNOPHARMACOLOGICAL RELEVANCE: Snakebite envenomation (SBE) is the world's most lethal neglected tropical disease. Bothrops jararaca is the species that causes the greatest number of SBEs in the South and Southeastern of Brazil. The main symptoms are local (inflammation, edema, hemorrhage, and myonecrosis) and systemic (hemorrhage, hemostatic alterations with consumptive coagulopathy, and death) effects. Species of the genus Siparuna, Siparunaceae, are used in folk and traditional medicine to treat SBE. However, limited information is available concerning Brazilian Siparuna species against SBE. AIM OF THE STUDY: To investigate the correlation between the compounds present in the extracts of five Siparuna species as potential agents against proteolytic activity, plasma coagulation, and phospholipase A2 (PLA2) activity caused by B. jararaca venom, using data obtained by UHPLC-MS/MS, biological activity, and multivariate statistics. MATERIALS AND METHODS: The ethanol extracts from leaves of S. ficoides, S. decipiens, S. glycycarpa, S. reginae, and S. cymosa were fractionated by liquid-liquid extraction using different solvents of increasing polarity (hexane, dichloromethane, ethyl acetate, and n-butanol), affording their respective extracts, totaling 25 samples that were assayed through in vitro plasma coagulation and proteolytic activity assays. Moreover, the extracts were analyzed by UHPLC-MS/MS, using electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI) in negative and positive ionization modes. The data was processed in MZmine v. 2.53 and evaluated by multivariate statistical tests (PLS) using the software UnscramblerX v. 10.4. These data were also used to build molecular networks (GNPS), and some ions of interest could be annotated using the library of molecules on the GNPS platform. RESULTS: A total of 19 extracts inhibited B. jararaca-induced plasma coagulation, with emphasis on S. cymosa and S. reginae (800 s). The inhibition of the proteolytic activity was also promising, ranging from 16% (S. glycycarpa) to 99% (S. cymosa, S. decipiens, and S. reginae). In addition, most extracts from S. cymosa and S. reginae inhibited 70-90% of PLA2 activity. Based on data from positive mode APCI analyses, it was possible to obtain a statistic model with reliable predictive capacity which exhibited an average R2 of 0.95 and a Q2 of 0.88, indicating a robust fit. This process revealed five ions, identified as the alkaloids: coclaurine (1), stepholidine (2) O-methylisopiline (3), nornantenine (4) and laurolitsine (5). This is the first study to evidence the potential antivenom of alkaloids from Siparuna species. CONCLUSIONS: Altogether, our results give support to the popular use of Siparuna extracts in SBE accidents, suggesting their potential as an alternative or complementary strategy against envenoming by B. jararaca venom. The predicted ions in the chemometric analysis for the assayed activities can also be correlated with the blocking activity and encourage the continuation of this study for possible isolation and testing of individual compounds on the used models.

Molecular Aspects Involved in the Mechanisms of Bothrops jararaca Venom-Induced Hyperalgesia: Participation of NK1 Receptor and Glial Cells.

Accidents caused by Bothrops jararaca (Bj) snakes result in several local and systemic manifestations, with pain being a fundamental characteristic. The inflammatory process responsible for hyperalgesia induced by Bj venom (Bjv) has been studied; however, the specific roles played by the peripheral and central nervous systems in this phenomenon remain unclear. To clarify this, we induced hyperalgesia in rats using Bjv and collected tissues from dorsal root ganglia (DRGs) and spinal cord (SC) at 2 and 4 h post-induction. Samples were labeled for Iba-1 (macrophage and microglia), GFAP (satellite cells and astrocytes), EGR1 (neurons), and NK1 receptors. Additionally, we investigated the impact of minocycline, an inhibitor of microglia, and GR82334 antagonist on Bjv-induced hyperalgesia. Our findings reveal an increase in Iba1 in DRG at 2 h and EGR1 at 4 h. In the SC, markers for microglia, astrocytes, neurons, and NK1 receptors exhibited increased expression after 2 h, with EGR1 continuing to rise at 4 h. Minocycline and GR82334 inhibited venom-induced hyperalgesia, highlighting the crucial roles of microglia and NK1 receptors in this phenomenon. Our results suggest that the hyperalgesic effects of Bjv involve the participation of microglial and astrocytic cells, in addition to the activation of NK1 receptors.

Understanding Local Reactions Induced by Bothrops jararaca Venom: The Role of Inflammatory Mediators in Leukocyte-Endothelium Interactions.

In recent years, extensive research has delved into the pathophysiology of local reactions triggered by Bothrops snake venoms. Even though antivenom works well at reducing death and systemic effects, it is still not very effective in treating local reactions because it cannot counteract damage that has already been triggered. This limitation might be attributed to certain molecules that amplify the venom-induced innate response. While evidence suggests endogenous mediators at the venom site play a role in this envenomation, in Brazil, the concurrent use of anti-inflammatory agents or other drugs alongside antivenom remains uncommon. This study evaluated the pharmacological mediation of alterations in leukocyte-endothelium interactions following the experimental envenomation of mice with Bothrops jararaca venom, the main culprit of snake-related accidents in Southeast Brazil. We treated envenomed mice with inhibitors of different pharmacological pathways and observed the cremaster muscle microcirculation with intravital microscopy. We found that eicosanoids related to cyclooxygenase pathways and nitric oxide significantly contributed to B. jararaca venom-induced alterations in leukocyte-endothelium interactions. Conversely, lipoxygenase-mediated eicosanoids, histamine, and serotonin had minimal participation. Notably, dexamethasone and antivenom treatment diminished B. jararaca venom-induced alterations in leukocyte-endothelium interactions. The limited efficacy of the antivenom in managing Bothrops venom-induced local reactions emphasizes the critical need for supplementary treatments to enhance therapeutic outcomes.

Biomedical and Biotechnological Potential of Animal Venoms: Bothrops Snake Venoms and their Antimicrobial Applications.

The pursuit of novel treatment alternatives to address the accumulated resistance to antimicrobials over the years has prompted the scientific community to explore biodiversity, particularly animal venom, as a potential source of new antimicrobial drugs. Snake venoms, with their complex mixtures of components, are particularly promising targets for investigation in this regard. The search for novel molecules exhibiting antimicrobial activity against multidrug-resistant strains is of paramount importance for public health and numerous research groups worldwide. High expectations within the healthcare field are supported by the scientific literature, which highlights the potential development of innovative drugs through in vivo and in vitro application, depending on dose titration. Snake venoms and their molecules and peptides offer exponential possibilities for biotechnological applications as antimicrobial agents. However, many uncertainties and unexplored avenues remain, presenting opportunities for discoveries and research.

Effect of Seaweed-Derived Fucoidans from Undaria pinnatifida and Fucus vesiculosus on Coagulant, Proteolytic, and Phospholipase A2 Activities of Snake Bothrops jararaca, B. jararacussu, and B. neuwiedi Venom.

BACKGROUND: Snakebite envenomation (SBE) causes diverse toxic effects in humans, including disability and death. Current antivenom therapies effectively prevent death but fail to block local tissue damage, leading to an increase in the severity of envenomation; thus, seeking alternative treatments is crucial. METHODS: This study analyzed the potential of two fucoidan sulfated polysaccharides extracted from brown seaweeds Fucus vesiculosus (FVF) and Undaria pinnatifida (UPF) against the fibrinogen or plasma coagulation, proteolytic, and phospholipase A2 (PLA2) activities of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom. The toxicity of FVF and UPF was assessed by the hemocompatibility test. RESULTS: FVF and UPF did not lyse human red blood cells. FVF and UPF inhibited the proteolytic activity of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom by approximately 25%, 50%, and 75%, respectively, while all venoms led to a 20% inhibition of PLA2 activity. UPF and FVF delayed plasma coagulation caused by the venoms of B. jararaca and B. neuwiedi but did not affect the activity of B. jararacussu venom. FVF and UPF blocked the coagulation of fibrinogen induced by all these Bothropic venoms. CONCLUSION: FVF and UPF may be of importance as adjuvants for SBE caused by species of Bothrops, which are the most medically relevant snakebite incidents in South America, especially Brazil.

Bothrops lanceolatus Envenoming in Martinique: A Historical Perspective of the Clinical Effectiveness of Bothrofav Antivenom Treatment.

Bothrofav, a monospecific antivenom, was introduced in June 1991 and has shown excellent effectiveness against life-threatening and thrombotic complications of Bothrops lanceolatus envenoming. Because of the reoccurrence of cerebral stroke events despite the timely administration of antivenom, new batches of Bothrofav were produced and introduced into clinical use in January 2011. This study's aim was to evaluate the effectiveness of Bothrofav generations at treating B. lanceolatus envenoming. During the first period of the study (2000-2010), 107 patients were treated with vials of antivenom produced in June 1991, while 282 envenomed patients were treated with vials of antivenom produced in January 2011 in the second study period (2011-2023). Despite timely antivenom administration, thrombotic complications reoccurred after an interval free of thrombotic events, and a timeframe analysis suggested that the clinical efficacy of Bothrofav declined after it reached its 10-year shelf-life. In of the case of an antivenom shortage due to the absence of regular batch production, no adverse effects were identified before the antivenom reached its 10-year shelf-life, which is beyond the accepted shelf-life for a liquid-formulation antivenom. While our study does not support the use of expired antivenom for potent, life-threatening B. lanceolatus envenoming, it can be a scientific message to public entities proving the necessity of new antivenom production for B. lanceolatus envenoming.

Immunochemical Recognition of Bothrops rhombeatus Venom by Two Polyvalent Antivenoms.

The protein profile of Bothrops rhombeatus venom was compared to Bothrops asper and Bothrops atrox, and the effectiveness of antivenoms from the National Institute of Health of Colombia (INS) and Antivipmyn-Tri (AVP-T) of Mexico were analyzed. Protein profiles were studied with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and reverse-phase high-performance liquid chromatography (RP-HPLC). The neutralizing potency and the level of immunochemical recognition of the antivenoms to the venoms were determined using Western blot, affinity chromatography, and enzyme-linked immunosorbent assay (ELISA). Bands of phospholipase A2 (PLA2), metalloproteinases (svMPs) I, II, and III as well as serine proteinases (SPs) in the venom of B. rhombeatus were recognized by SDS-PAGE. With Western blot, both antivenoms showed immunochemical recognition towards PLA2 and svMP. INS showed 94% binding to B. rhombeatus venom and 92% to B. asper while AVP-T showed 90.4% binding to B. rhombeatus venom and 96.6% to B. asper. Both antivenoms showed binding to PLA2 and svMP, with greater specificity of AVP-T towards B. rhombeatus. Antivenom neutralizing capacity was calculated by species and mL of antivenom, finding the following for INS: B. asper 6.6 mgV/mL, B. atrox 5.5 mgV/mL, and B. rhombeatus 1.3 mgV/mL. Meanwhile, for AVP-T, the following neutralizing capacities were found: B. asper 2.7 mgV/mL, B. atrox 2.1 mgV/mL, and B. rhombeatus 1.4 mgV/mL. These results show that both antivenoms presented similarity between calculated neutralizing capacities in our trial, reported in a product summary for the public for the B. asper species; however, this does not apply to the other species tested in this trial.

Viperidae snake envenomation from a highly complex hospital in southwestern Colombia.

Background: Snake envenomation is a medical condition with high morbidity and mortality in southwestern Colombia. Objectives: To describe the characteristics of the envenomation caused by Viperidae snakes view in a highly complex hospital in Southwestern Colombia. Methods: A cross-sectional study was carried out. Patients treated for Viperidae snake envenomation from 2001 to 2020 in a Hospital Fundación Valle del Lili, Cali, Colombia, were studied. Results: Twenty-eight patients were included. Envenomation was caused by the genera Bothrops, Bothriechis, Porthidium, and Bothrocophias. The median age was 37.7 (±20.6), and they were predominantly male (19, 68%). Bites occurred on the upper extremities in 16 (57%) patients. Pain (23, 81%) and edema (22, 78%) were the most common clinical symptoms. Thirteen (46%) patients presented coagulopathy. Prolonged prothrombin and activated partial thromboplastin times were common: (22, 78% and 15, 53%, respectively). Twenty (71%) patients were treated with polyvalent antivenom (median dose of 6 (2-15) vials). The median time between the accident and antivenom administration was 9 h (5.5-17). Door-to-needle time was 37.5 (0-62) min. Eighteen (64%) patients were admitted to the intensive care unit. Three (11%) patients had serum sickness. Seven (25%) developed infectious complications, four (14%) had surgery, one (3%) had compartment syndrome, one (3%) underwent amputation of the affected limb, and one (3%) patient died. Conclusions: Local manifestations and coagulopathy were common clinical features. Polyvalent antivenom was an effective treatment for disease control. Significant complications were associated with delays in seeking medical care.

A Cytotoxicity Assay as an Alternative to the Murine Model for the Potency Testing of Bothrops jararaca Venom and Antivenom: An Intralaboratory Pre-validation Study.

Antivenom therapy is the only specific treatment for snakebite envenomation, and antivenom potency determination is key in the efficacy assurance quality control process. Nowadays, this process relies on the in vivo murine model - thus, the development of alternative in vitro methods is imperative. In the current study, the principle of the proposed method is the ability of Bothrops venom to induce cytotoxic effects in Vero cells, and the capacity to evaluate the inhibition of this cytotoxicity by the respective antivenom. After exposure to the venom/antivenom, the relative proportions of adherent (viable) cells were evaluated by direct staining with Coomassie Blue. The optical density (OD) of the lysed cell eluate was directly proportional to the number of adherent cells. This cytotoxicity-based alternative method could represent a potential candidate for validation as a replacement for the current in vivo test. The in vitro-determined cytotoxicity of the Brazilian Bothrops reference venom (expressed as the 50% effective concentration; EC50) was 3.61 µg/ml; the in vitro-determined 50% inhibitory concentration (IC50) of the Brazilian Bothrops reference antivenom was 0.133 µl/ml. From these two values, it was possible to calculate the potency of the reference antivenom. The results from the assays exhibited a good linear response, indicating that the method could be a potential candidate replacement method for use in antivenom quality control prior to lot release, subject to further validation.

Evaluation of the immunomodulatory effect of Bougainvillea xbuttiana (Var. Orange) on the cytokine production induced by Botrhops jararaca venom in macrophages / Evaluación del efecto inmunomodulador de Bougainvillea xbuttiana (var. naranja) sobre la producción de citoquinas de macrófagos inducida pelo veneno de Bothrops jararaca

To study the effect of 50% ethanol extract of Bougainvillea xbuttiana on the enzymatic activity, cell via bility and cytokine production provoked by the venom of Bothrops jararaca in macro - phages. Three assays were used to study the effects of B. xbuttiana extract on the damage pro - duced by B. jararaca : Enzymatic activity was detected by measuring the proteoly tic and phos - pholipase A2; macrophages cytotoxicity was determined by the MTT method; levels of cytokine were evaluated using ELISA and a biological assay. After treatment with 300 µg/mL B. xbuttiana extract for 30 min, the proteolytic and phospholipase A2 activities of the venom were reduced to 95 and 61%, respectively. In macrophages cultures treated with B. xbuttiana extract combined with venom, the production of TNF - α, IL - 6 and IFN - γ was reduced, whereas IL - 10 was potenti - ated. Our results support the potential effect of the B. xbuttiana extract as a complementary therapy against the toxicity caused by the venom of B . jararaca snakes

Estudiar el efecto del extracto etanólico al 50% de Bougainvillea xbuttiana sobre la actividad enzimática viabilidad celular y producci ón de citoquinas provocada por el veneno de Bothrops jararaca en macrófagos Se utilizaron tres ensayos para estudiar los efectos del extracto de B. xbuttiana sobre el daño producido por B. jararaca : Se detectó actividad enzimática mediante la medición del proteolítico y fosfolipasa A2; la citotoxicidad de los macrófagos se determinó por el método MTT; Los niveles de citoquinas se evaluaron utilizando ELISA y un ensayo biológico. Después del tratamiento con 300 µg/mL de extracto de B. xbuttiana durante 30 mi n, las actividades proteolíticas y de fosfolipasa A2 del veneno se redujeron a 95 y 61%, respectivamente. En cultivos de macrófagos tratados con extracto de B. xbuttiana combinado con veneno, la producción de TNF - α, IL - 6 e IFN - γ se redujeron, mientras que IL - 10 se potenció. Nuestros resultados apoyan el efecto potencial del extracto de B. xbuttiana como terapia complementaria frente a la toxicidad provocada por el veneno de B. jararaca .

Long-term hospital care needs after Bothrops atrox envenomation with hemorrhagic stroke in the Brazilian Amazon: 'From social to physical death' - A case report.

Hemorrhagic stroke is a severe complication reported in cases of Bothrops atrox snakebite envenomation. We report an unusual case of a patient who evolved with an intracranial hemorrhagic stroke and was in a coma for more than five years in a tertiary hospital located in Manaus, Amazonas. 52-year-old man, carpenter, resident in the rural area of the municipality of Tabatinga, located 1106 km from Manaus, capital of Amazonas, Brazil, victim of an accident involving Bothrops atrox evolution with cardiorespiratory arrest, acute kidney injury and hemorrhagic stroke. After 43 days of hospitalization in the ICU, he was transferred to the ward, without contact with the environment and family, sent for home treatment, however, without acceptance by family members. During a long hospital stay for a period of 6 years, totally dependent on special care, in a flexed position, using a tracheostomy and mechanical ventilation, diagnosed and treated for hospital infections throughout his hospitalization, he died due to bacterial pneumonia. Losses of autonomy can result in an individual being completely disconnected from social life - a "social death before physical death".

Activation of M1 muscarinic acetylcholine receptors by proline-rich oligopeptide 7a (Bothrops jararaca snake venom rescues oxidative stress-induced neurotoxicity in PC12 cells.

Background: The bioactive peptides derived from snake venoms of the Viperidae family species have been promising as therapeutic candidates for neuroprotection due to their ability to prevent neuronal cell loss, injury, and death. Therefore, this study aimed to evaluate the cytoprotective effects of a synthetic proline-rich oligopeptide 7a (PRO-7a;

Panicolytic-like effects of environment enrichment on male mice threatened by Bothrops jararaca lancehead pit vipers.

Environment enrichment (EE) is a well-known eustress model showing beneficial effects in different psychiatric diseases, but its positive properties in panic disorders are not yet established. The confrontation between prey and predator in complex arenas has been validated as a putative panic attack model. The principal aim of this work was to investigate the role of the EE on panic-like defensive responses elicited by mice threatened by venomous snakes. After 6 weeks of exposure either to an enriched or standard environments, 36 male mice were habituated in a complex polygonal arena for snakes containing an artificial burrow and elevated platforms for escape. The animals were confronted by Bothrops jararaca for 5 min, and the following antipredatory responses were recorded: defensive attention, stretched attend posture, flat back approach, prey versus predator interaction, oriented escape behavior, time spent in a safe place, and number of crossings. Mice threatened by snakes displayed several antipredatory reactions as compared to the exploratory behavior of those animals submitted to a nonthreatening situation (toy snake) in the same environment. Notably, EE causes anxiolytic- and panicolytic-like effects significantly decreasing the defensive attention and time spent in safe places and significantly increasing both prey versus predator interaction and exploratory behavior. In conclusion, our data demonstrate that EE can alter the processing of fear modulation regarding both anxiety- and panic-like responses in a dangerous condition, significantly modifying the decision-making defensive strategy.

Venom Composition of Neglected Bothropoid Snakes from the Amazon Rainforest: Ecological and Toxinological Implications.

Snake venoms have evolved in several families of Caenophidae, and their toxins have been assumed to be biochemical weapons with a role as a trophic adaptation. However, it remains unclear how venom contributes to the success of venomous species for adaptation to different environments. Here we compared the venoms from Bothrocophias hyoprora, Bothrops taeniatus, Bothrops bilineatus smaragdinus, Bothrops brazili, and Bothrops atrox collected in the Amazon Rainforest, aiming to understand the ecological and toxinological consequences of venom composition. Transcriptomic and proteomic analyses indicated that the venoms presented the same toxin groups characteristic from bothropoids, but with distinct isoforms with variable qualitative and quantitative abundances, contributing to distinct enzymatic and toxic effects. Despite the particularities of each venom, commercial Bothrops antivenom recognized the venom components and neutralized the lethality of all species. No clear features could be observed between venoms from arboreal and terrestrial habitats, nor in the dispersion of the species throughout the Amazon habitats, supporting the notion that venom composition may not shape the ecological or toxinological characteristics of these snake species and that other factors influence their foraging or dispersal in different ecological niches.

Insuficiencia cardíaca secundaria a mordedura de serpiente. La visión del intensivista: Reporte de caso / Heart failure secondary to a snake bite. The intensivist's vision: Case Report

RESUMEN Antecedentes: El accidente ofídico es una enfermedad desatendida que afecta a los países tropicales. América Latina es la segunda región después de África, con mayor número de casos a nivel mundial. Su curso clínico incluye lesiones locales hasta afectaciones sistémicas como lesiones renales, hematológicas y neurológicas. Las complicaciones cardiacas son raras, especialmente en pacientes que no tienen factores de riesgo cardiovascular. Hay reportes de infarto agudo de miocardio, pero existe poca información sobre la insuficiencia cardíaca debida a Bothrops spp. Reporte de caso: Presentamos el caso de un hombre de 25 años sin factores de riesgo cardiovascular que fue admitido en la unidad de cuidados intensivos y desarrolló insuficiencia cardíaca con choque cardiogénico y fallo multiorgánico secundario a una mordedura de serpiente. Conclusiones: Aunque el curso clínico característico de un accidente ofídico bothrópico y sus manifestaciones sistémicas están principalmente relacionadas con anomalías de la coagulación, hay complicaciones cardiovasculares dentro de su presentación clínica que, aunque raras, si no se detectan prontamente y no se manejan adecuadamente, están asociadas con alta morbilidad y mortalidad.

ABSTRACT Background: Ophidic accident is a neglected disease that affects tropical countries. Latin America is the second region after Africa, with the most cases worldwide. Local lesions accompany its clinical course up to systemic affectations such as renal, hematological, and neurological lesions. Cardiac complications are rare, especially in patients who do not have cardiovascular risk factors. There are reports of acute myocardial infarction, but there is little information about heart failure due to Bothrops spp. Case report: We present the case of a 25-year-old man without cardiovascular risk factors who was admitted to the intensive care unit and developed heart failure with cardiogenic shock and multi-organ failure secondary to a snake bite. Conclusions: Although the characteristic clinical course of a bothropic ophidian accident and its systemic manifestations are mainly related to coagulation abnormalities, there are cardiovascular complications within its clinical presentation that, although rare, if not detected promptly and not adequately managed, are associated with high morbidity and mortality.

A novel metalloproteinase-derived cryptide from Bothrops cotiara venom inhibits angiotensin-converting enzyme activity.

Snake venoms are primarily composed of proteins and peptides, which selectively interact with specific molecular targets, disrupting prey homeostasis. Identifying toxins and the mechanisms involved in envenoming can lead to the discovery of new drugs based on natural peptide scaffolds. In this study, we used mass spectrometry-based peptidomics to sequence 197 peptides in the venom of Bothrops cotiara, including a novel 7-residue peptide derived from a snake venom metalloproteinase. This peptide, named Bc-7a, features a pyroglutamic acid at the N-terminal and a PFR motif at the C-terminal, homologous to bradykinin. Using FRET (fluorescence resonance energy transfer) substrate assays, we demonstrated that Bc-7a strongly inhibits the two domains of angiotensin converting enzyme (Ki < 1 µM). Our findings contribute to the repertoire of biologically active peptides from snake venoms capable of inhibiting angiotensin-converting enzyme (ACE), beyond current known structural motifs and precursors. In summary, we report a novel snake venom peptide with ACE inhibitory activity, suggesting its potential contribution to the hypotensive effect observed in envenomation.