Bothrops Jararaca Research Articles

Intramuscular injection of Bothrops jararaca venom provoked acute kidney injury (AKI): Underpinned by impaired renal filtration, Na+ handling, and tissue damage

Globally, about 2.5 million people are victims of snakebites annually. In Brazil, the most clinically relevant snake is the Bothrops jararaca. The symptoms of envenomation are acute inflammation at the bite site and bleeding disorders. Despite kidney failure being the main cause of death after envenomation, kidney damage is not completely understood, and there are no clinically representative in vivo models. This work aimed to characterize the acute kidney injury (AKI) induced by intramuscular injection (IM) of Bothrops jararaca (Bjc) venom in male Wistar rats. The control group received 0.9% saline solution. Three doses of venom (3.5, 6.0, and 8.0 mg/kg) were administered IM into the posterior region of the right knee. After the injection, the rats were kept in metabolic cages. The following parameters were analyzed after 24 h: the extent of muscle damage and kidney damage (urinary creatinine, proteinuria, plasma creatinine, and renal tissue histology). All rats presented a hemorrhagic lesion at the injection site in a dose-dependent manner. Biochemical parameters indicated kidney damage: plasma creatinine accumulation, decreased glomerular filtration rate, albuminuria and proteinuria, and disturbance in Na+ homeostasis. Histological analyses showed glomerular injury, tissue discontinuity more evident in the cortex and tubular dilatation, and collagen deposition. The decline in renal function and tissue damage indicated the occurrence of AKI. Therefore, a Bjc venom-induced in vivo model of renal injury has been established for future studies.

Designing 1,2,3‐Triazole Derivatives for Targeted Inhibition of Proteolytic and Coagulant Activities in Bothrops Jararaca and Bothrops neuwiedi Snake Venoms

AbstractSnakebites inflict significant injuries on humans and animals, posing a severe global public health challenge due to high mortality and morbidity rates. This study presents results against the venoms of Bothrops jararaca and Bothrops neuwiedi using sixteen synthetic hybrid molecules containing thiophene and triazoles, designated as 6a–h and 7a–h. The compounds were assessed for their ability to inhibit proteolytic and plasma coagulant activities induced by the snake venoms, and their toxicity was analyzed. Most derivatives demonstrated nontoxicity through in silico analysis with the Osiris Property Explorer tool and in vitro cytotoxic hemocompatibility on red blood cells. Notably, only derivative 6e exhibited toxicity to erythrocytes, while 6b, 6d, 7c, and 7f displayed mutagenic, tumorigenic, or adverse effects on the reproductive system. Derivatives 6a, 6c–h, 7c–e, 7g, or 7h effectively inhibited the coagulating activity of B. jararaca venom, while 6a–b, 6d–e, 6h, or 7a–f inhibited coagulation induced by B. neuwiedi venom. All derivatives demonstrated inhibition of the proteolytic activity caused by B. jararaca venom, and derivatives 6a–d and 7e–f inhibited the activity of B. neuwiedi venom. Consequently, these derivatives exhibited varying degrees of efficacy in countering two crucial toxic effects of B. jararaca or B. neuwiedi venoms, suggesting their potential as antivenoms against both species.

Ultrasound and Gold Nanoparticles Improve Tissue Repair for Muscle Injury Caused by Snake Venom

ObjectiveTo develop a treatment that enhances recovery from envenomation-induced lesions caused by Bothrops jararaca venom by using ultrasound in combination with gold nanoparticles (GNPs). MethodsA total of 108 Swiss mice were arranged into nine groups. The animals underwent necrotic induction with 250 µg B. jararaca venom (BjV) and were treated with ultrasound (U) at 1 MHz frequency at an intensity of 0.8 W/cm² for 5 min, 30 mg/L GNPs, and anti-bothropic serum (AS) in the following combinations: saline solution (SS); BjV; BjV + AS; BjV + AS + U; BjV + GNPs + AS; BjV + GNPs + AS + U; BjV + GNPs; BjV + GNPs + U; and BjV + U. The necrotic area, histology, oxidative stress, oxidative damage, and anti-oxidant system were assessed to evaluate the effects of the treatments. ResultsTreatments that included GNPs, U, and/or AS demonstrated reductions in necrotic area, increases in angiogenesis and fibroblast means, decreases in inflammatory infiltrates, and improvements in collagen synthesis. Additionally, there was an increase in oxidants and oxidant damage within the gastrocnemius muscle, along with an increase in anti-oxidants. Furthermore, systemic effects appear to have been achieved, improving the anti-oxidant system at the cardiovascular and renal levels. ConclusionThe use of GNPs and U may be effective at treating lesions caused by B. jararaca snake venom.

Biotechnological potential of Brazilian snake venom in the production of biologically active drugs: Literature review

Despite being feared, Brazilian venomous snakes can be reservoirs of important resources of medicinal interest, since the venoms of these animals have an invaluable potential for biologically active substances found in nature. Pharmacological and biochemical studies carried out in recent decades have shown the diversity of proteins with enzymatic activity, toxins, peptides, bioactive amines, among other compounds in snake venoms. The aim of this literature review was to describe the pharmaceutical biotechnological potential of Brazilian snake venom and to demonstrate the importance of these toxins and their pharmacological derivatives for public health. Since 1894, when they were studied by Vital Brazil, molecules derived from Brazilian snake venom have shown significant biological activity. These molecules have been proven to be efficient antimicrobial, antifungal and antiprotozoal agents, mainly due to their activity as serine proteases, hyaluronidases, L-amino acid oxidases (LAAO) and acetylcholinesterases, among other well-known substances. Brazilian snake venoms have thus been the target of a series of studies, which have borne excellent fruit, for example in the development of various drugs, such as Captopril®, which is derived from a peptide isolated from the venom of Bothrops jararaca, and fibrin sealant, derived from molecules in the venom of Crotalus durissus terrificus associated with cryoprecipitate from the blood plasma of buffaloes. With the analysis of biotechnologies applied to various molecules with the capacity for pharmacological, biologically active action, it is clear that this field is vast for new research and due to the great diversity of compounds in snake venoms. Certainly, as research progresses, new biologically active drugs derived from snake venom should become available for use and benefit of the population. Thus, studies related to the chemical composition of snake venoms should be encouraged, as well as those related to their pharmaceutical biotechnological potential.

Small Structural Differences in Proline-Rich Decapeptides Have Specific Effects on Oxidative Stress-Induced Neurotoxicity and L-Arginine Generation by Arginosuccinate Synthase.

The proline-rich decapeptide 10c (Bj-PRO-10c; ENWPHPQIPP) from the Bothrops jararaca snake modulates argininosuccinate synthetase (AsS) activity to stimulate L-arginine metabolite production and neuroprotection in the SH-SY5Y cell line. The relationships between structure, interactions with AsS, and neuroprotection are little known. We evaluated the neuroprotective effects of Bj-PRO-10c and three other PROs (Bn-PRO-10a, <ENWPRPKIPP; Bn-PRO-10a-MK, <ENWPRPKIPPMK; and, Bn-PRO-10c, <ENWPRPKVPP) identified from Bitis nasicornis snake venom, with a high degree of similarity to Bj-PRO-10c, on oxidative stress-induced toxicity in neuronal PC12 cells and L-arginine metabolite generation via AsS activity regulation. Cell integrity, metabolic activity, reactive oxygen species (ROS) production, and arginase activity were examined after 4 h of PRO pre-treatment and 20 h of H2O2-induced damage. Only Bn-PRO-10a-MK and Bn-PRO-10c restored cell integrity and arginase function under oxidative stress settings, but they did not reduce ROS or cell metabolism. The MK dipeptide in Bn-PRO-10a-MK and valine (V8) in Bn-PRO-10c are important to these effects when compared to Bn-PRO-10a. Bj-PRO-10c is not neuroprotective in PC12 cells, perhaps because of their limited NMDA-type glutamate receptor activity. The PROs interaction analysis on AsS activation can be rated as follows: Bj-PRO-10c > Bn-PRO-10c > Bn-PRO-10a-MK > Bn-PRO-10a. The structure of PROs and their correlations with enzyme activity revealed that histidine (H5) and glutamine (Q7) in Bj-PRO-10c potentiated their affinity for AsS. Our investigation provides the first insights into the structure and molecular interactions of PROs with AsS, which could possibly further their neuropharmacological applications.

Bioactive peptides (cryptides) obtained by Bothrops jararaca serine peptidases action on myoglobin

Serine peptidases and metallopeptidases are the primary toxins found in Bothrops snakes venoms, which act on proteins in the tissues of victims or prey, and release of peptides formed through proteolytic activity. Various studies have indicated that these peptides, released by the proteolytic activity of heterologous enzymes, generate molecules with unidentified functions, referred to as cryptids. To address this, we purified serine peptidases from Bothrops jararaca venom using molecular exclusion chromatography and then incubated them with the endogenous substrate myoglobin. As a control, we also incubated the substrate with trypsin. The resulting proteolytic fragments were analyzed, separated, and collected via HPLC. These fractions were then tested on cell cultures, the active fractions were sequenced (ALELFR and TGHPETLEK) and synthesized. After confirming their activity, the peptides underwent sequencing and synthesis for additional cell tests, including the increase of cell viability, cycle phases, proliferation, signaling, growth kinetics, angiogenesis, and migration. The results revealed that the synthesized peptides exhibited cellular repair properties, suggesting a potential role in tissue repair in the range of 0.05–5 μ M. Additionally, the effects of fragments resulting from myoglobin degradation isolated (ALELFR and TGHPETLEK) revealed a regenerative action on tissue.

Are Bergmann's and Jordan's rules valid for a neotropical pitviper?

AbstractMorphological variation along the spatial distribution of species has been extensively investigated in ecological studies, and several ecogeographical rules explore the relationships between morphological traits and the environment. Many morphological traits are correlated, providing an opportunity to evaluate the validity of multiple ecogeographical rules simultaneously. Bergmann's rule predicts that endothermic animals in colder locations are larger than those in warmer locations. Jordan's rule predicts that fish from colder locations have more vertebrae than those from warmer locations. We tested the validity of Bergmann's and Jordan's rules for the neotropical lancehead snake Bothrops jararaca. We evaluated three morphological characters of 342 specimens: number of ventral scales (proxy for vertebrae number), snout–vent length (a linear measure of body size) and stoutness (volumetric body size). We implemented spatial regressions to evaluate the variation of morphological dimensions using climatic predictors: the minimum temperature and evapotranspiration. SVL was poorly related to minimum temperature and evapotranspiration. However, stouter individuals were found in colder places with greater evapotranspiration, following Bergmann's rule and the water conservation hypothesis. Individuals in warmer locations also had a greater number of ventral scales, reversing Jordan's rule. We showed that different selective pressures act on different morphological dimensions. Although stoutness follows Bergmann's rule, its variation would arise from an energy storage demand rather than heat conservation. Also, stoutness variation along evapotranspiration gradients could represent a mechanism to avoid hydric stress in environments with considerable climatic variations. The variation in vertebrae number along temperature gradients could be related to ecological factors and foraging. We highlight that physioecological mechanisms to deal with climatic variation and ecological aspects could be identified in snakes through intraspecific analyses, contrasting with interspecific studies that can hardly detect general trends. Due to different environmental effects on body size, we shed new light on the importance of exploring multiple morphological dimensions in macroecological studies.

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 relevanceSnakebite 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 studyTo 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 methodsThe 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. ResultsA 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. ConclusionsAltogether, 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.

Study of defensive behavior of a venomous snake as a new approach to understand snakebite

Snakebites affect millions of people worldwide. The majority of research and management about snakebites focus on venom and antivenom, with less attention given to snake ecology. The fundamental factor in snakebites is the snakes’ defensive biting behavior. Herein we examine the effects of environmental variables (temperature, time of day, and human stimulus) and biological variables (sex and body size) on the biting behavior of a medically significant pit viper species in Brazil, Bothrops jararaca (Viperidae), and associate it with the epidemiology of snakebites. Through experimental simulations of encounters between humans and snakes, we obtained behavioral models applicable to epidemiological situations in the State of São Paulo, Brazil. We found a significant overlap between behavioral, morphological, environmental, and epidemiological data. Variables that increase snakebites in epidemiological data also enhance the tendency of snakes to bite defensively, resulting in snakebites. We propose that snakebite incidents are influenced by environmental and morphological factors, affecting the behavior of snakes and the proportion of incidents. Thus, investigating behavior of snakes related to snakebite incidents is a valuable tool for a better understanding of the epidemiology of these events, helping the prediction and, thus, prevention of snakebites.

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.

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. 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. 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. 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.

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.

Food preference for native and invasive prey in the naive lancehead pitviper

AbstractThe presence of invasive species in the environment can be highly detrimental. The success of these species depends on their interaction with native ones. The prey–predator relationship between invasive and native species can result in biodiversity loss or the introduction of new food items for local predators. Due to its tropical and extensive nature, Brazil is vulnerable to the colonization of invasive species. Snakes are a group of animals that can act as both predators and prey for invasive species. The pitviper Bothrops jararaca is an abundant and widely distributed native species on the Brazilian coast. Based on this, we conducted a study on the feeding preferences of naive B. jararaca juveniles regarding invasive and native prey. We found that this species exhibits a greater preference for native anurans compared to Rana catesbeiana, an invasive amphibian associated with significant environmental impacts. Additionally, the gecko Hemidactylus mabouia, a prey that triggered intense predatory responses from the pitviper, reveals that this species, even with a short period of coexistence with B. jararaca, has established an intense prey–predator relationship. The negative correlation between prey size and feeding interest, guided solely by olfactory cues, adds a layer of complexity to understanding the feeding choices of B. jararaca, providing valuable insights for conservation and environmental management strategies.Abstract in Portuguese is available with online material.

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.

Anti-inflammatory, healing and antiophidic potential of Jatropha mollissima (Pohl) Baill. (Euphorbiaceae): From popular use to pharmaceutical formulation in gel

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.

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.

Geographic variation in the probability of being born with and retaining contrasting tail tip colour (tail luring) in the common lancehead Bothrops jararaca

In snakes which are known to be ambush predators, tail luring, in which the movement of a snake’s tail resembles that of a worm or insect larva and is used to attract prey, has emerged as a complementary hunting strategy. In certain species, some individuals may present a conspicuously bright colour at the tail tip which eventually disappears with age. Some authors argue that the bright colour enhances the resemblance of the snake’s tail with a potential food item, increasing the success of capture. Here, we tested the influence of geographic variation, sex, and environmental factors on the probability that common lanceheads Bothrops jararaca (Wied-Neuwied 1824) from southeastern Brazil were born with this contrasting tail tip and whether snakes retain this trait throughout adulthood. None of the predictors affected the probability of births with a contrasting tail tip. However, a higher proportion of individuals from the coastal populations retained this trait into adulthood. The absence of difference in the probability of being born with this trait indicates that there are other factors influencing tail tip colour, such as phylogenetic correlates, rather than intrinsic or environmental factors. A higher proportion of ectothermic prey in the diet of coastal populations may explain why this population retains tail-luring throughout adulthood.

Proteomics and life-history variability of Endogenous Phospholipases A2 Inhibitors (PLIs) in Bothrops jararaca plasma.

In Brazil, the genus Bothrops is responsible for most ophidian accidents. Snake venoms have a wide variety of proteins and peptides exhibiting a broad repertoire of pharmacological and toxic effects that elicit systemic injury and characteristic local effects. The snakes' natural resistance to envenomation caused by the presence of inhibitory compounds on their plasma have been extensively studied. However, the presence of these inhibitors in different developmental stages is yet to be further discussed. The aim of this study was to evaluate the ontogeny of Bothrops jararaca plasma inhibitor composition and, to this end, plasma samples of B. jararaca were obtained from different developmental stages (neonates, youngs, and adults) and sexes (female and male). SDS-PAGE, Western blotting, affinity chromatography, and mass spectrometry were performed to analyze the protein profile and interaction between B. jararaca plasma and venom proteins. In addition, the presence of γBjPLI, a PLA2 inhibitor previously identified and characterized in B. jararaca serum, was confirmed by Western blotting. According to our results, 9-17% of plasma proteins were capable of binding to venom proteins in the three developmental stages. The presence of different endogenous inhibitors and, more specifically, different PLA2 inhibitor (PLI) classes and antihemorrhagic factors were confirmed in specimens of B. jararaca from newborn by mass spectrometry. For the first time, the αPLI and βPLI were detected in B. jararaca plasma, although low or no ontogenetic and sexual correlation were found. The γPLI were more abundant in adult female, than in neonate and young female, but similar to neonate, young and adult male according to the results of mass spectrometry analysis. Our results suggest that there are proteins in the plasma of these animals that can help counteract the effects of self-envenomation from birth.

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.

Aqueous Extract and Solvent Fractions of Hancornia speciosa Fruits, Rutin, and Chlorogenic Acid Attenuate the Edema, Inflammation, and Myonecrosis Caused by Bothrops jararaca Snake Venom in Mice

Aqueous Extract and Solvent Fractions of Hancornia speciosa Fruits, Rutin, and Chlorogenic Acid Attenuate the Edema, Inflammation, and Myonecrosis Caused by Bothrops jararaca Snake Venom in Mice

Inhibition of Snake Venom Serine Proteases Activities by Specific Antibody

According to the World Health Organization, snake envenomation is a major neglected public health problem. In addition to deaths, these accidents cause other severe disabilities, such as amputations. Annually, around 2 million people worldwide are affected by snakebite, with Africa, Asia, and Latin America being the regions most affected. Snakes of the Bothrops genus are the main cause of snakebite accidents in Latin America. Serine proteases (SVSPs) are one of the main protein families that have been implicated in the alterations of the human hemostasis, which causes a tendency to increase thrombotic and hemorrhagic processes. Part of SVSPs, are thrombin-like enzymes (TLEs), which recognize and cleave human fibrinogen, but usually only releasing fibrinopeptide A or B and do not act on the coagulation Factor XIII. Consequently, these toxins contribute to coagulopathy by fibrinogen consumption, one of the major systemic hemostatic disturbances, frequently observed in snakebite victims. The bothropic antivenom is effective in reversing most of the systemic effects of envenomation when administered early in an adequate therapeutic dose. However, studies have demonstrated that, in some cases, antivenoms do not completely neutralize the action of SVSPs, which are co-responsible for systemic and local effects, such as coagulopathy and hemorrhage. In this context, a better understanding of SVSPs’ role in coagulopathy caused by envenomation, and developing new strategies to inhibit these toxins are important. To achieve this, we aimed in the current work to isolate an enriched pool of SVSPs from Bothrops jararaca and Bothrops atrox, to better understand the SVSPs’ interaction with murine monoclonal antibody (mAb) anti-SVSPs.