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Introduction Warfighters are exposed to life-threatening injuries daily and according to the Joint Trauma System Military Clinical Practice Guideline—Global Snake Envenomation Management snakebites are a concerning threat in all theaters of operation. Snake venom is a complex mixture of toxins including phospholipases A2 (PLA2) and snake venom metalloproteinases (SVMP) that produce myotoxic, hemotoxic, and cytotoxic injuries. Antibody-based antivenom is the standard of care but new approaches including small-molecule inhibitors have gained attention in recent years. Doxycycline is an effective inhibitor of human metalloproteinases and PLA2. The enzymatic activities of 3 phylogenetically distinct snakes: Agkistrodon piscivorus, Naja kaouthia , and Daboia russelii were tested under inhibitory conditions using doxycycline. Materials and Methods Enzymatic activity of PLA2 and SVMP was measured in N. kaouthia, D. russelii , and A. piscivorus venom alone and with doxycycline using EnzChek Phospholipase A2 and Gelatinase Assay Kits. A 1-way ANOVA with Tukey's post-hoc test was used to conduct comparative analysis. The median lethal dose of the venoms, the effective dose of doxycycline, and creatine kinase (CK) inhibition levels were measured in a murine model with adult Bagg Albino (BALB/c) mice using intramuscular injections. Median lethal and effective doses were determined using Spearman-Karber's method and a 1-way ANOVA with Tukey's post-hoc test was used to compare CK inhibition levels. Results Phospholipases A2 activity was reduced to 1.5% to 44.0% in all 3 venoms in a dose-dependent manner using 0.32, 0.16, and 0.08 mg/mL doxycycline when compared to venom-only controls (P  < .0001) (Fig. 1A). Snake venom metalloproteinases activity was reduced to 4% to 62% in all 3 venoms in a dose-dependent manner using 0.32, 0.16, and 0.08 mg/mL doxycycline (P  < .0001) (Fig. 1B). The lethal dose (LD50) values of the venoms in the murine model were calculated as follows: A. piscivorus  = 20.29 mg/kg (Fig. 2A), N. kaouthia  = 0.38 mg/kg (Fig. 2B), and D. russelii  = 7.92 mg/kg (Fig. 2C). The effective dose (ED50) of doxycycline in A. piscivorus was calculated to be 20.82 mg/kg and 72.07 mg/kg when treating D. russelii venom. No ED50 could be calculated when treating N. kaouthia venom (Fig. 3). Creatine kinase activity was significantly decreased in all 3 venoms treated with doxycycline (P  < .0001) (Fig. 4). FIGURE 1. In vitro doxycycline inhibition of PLA, and SVMP activity in whole venom. The AUC was calculated for PLA and SVMP activities for 20-min and 4-h time courses, respectively using EnzChek Phospholipase A2, assay kits, and EnzChek Gelatinase (SVMP) assay kits. (A) Inhibition of PLA2, with doxycycline (Dox) was tested at concentrations of 0.32 mg/mL, 0.16 mg/mL, and 0.08 mg/mL against A. piscivorus (4 μg/mL), N. kaouthia (4 μg/mL), and D. russelii (8 μg/mL) venom. A venom-only control was included. (B) Inhibition of SVMP with doxycycline was tested at concentrations of 0.32 mg/mL, 0.16 mg/mL, and 0.08 mg/mL against A. piscivorus (120 μg/ml.), N. kaouthia (125 μg/ml.), and D. russelii (250 μg/ml.). A venom-only control was included. An ordinary 1-way ANOVA with Tukey's post-hoc test was performed for inhibition assays to compare treatments to their respective venom controls. All error bars show mean ± SD, n  = 3, (****, P  < .0001). Open in new tab Download slide FIGURE 2. Percent survival of mice receiving various dosages for each venom studied and LDs, calculation. Adult BALB/c mice received intramuscular injections of various venom dosages for each venom, (A) A. piscivorus , (B) N. kaouthia , and (C) D. russelii. The resulting percent survival was measured across 48 h and the lethal dose 50 (LD50) was calculated using the Spearman-Karber method. In each graph, each treatment group (venom dosage) has n  = 5. Open in new tab Download slide FIGURE 3. Percent survival of mice receiving various doxycycline dosages for each venom studied and ED calculation. Adult BALB/c mice received intramuscular injections of various doxycycline dosages combined with 3 times the LD50 of cach venom [ A. piscivorus (AP) (60.87 mg/kg), N. kaouthia (NK) (1.14 mg/kg). D. russelii (DR) (23.76 mg/kg)] and the resulting percent survival was measured across 48 hours and the effective dose 50 (ED50) was calculated using the Spearman–Karber method. Each treatment group has n  = 5. Open in new tab Download slide FIGURE 4. Venom-induced CK activity with doxycycline-mediated inhibition. The amount of CK produced by mice exposed to one-fourth of the LD50, strength of A. piscivorus (AP) (5.07 mg/kg), N. kaouthia (NK) (0.095 mg/kg), or D. russelli (DR) (1.98 mg/kg) venom either with or without doxycycline (64 mg/kg). All error bars show mean, ± SD, n  = 5 (NaCl—Dox, AP NaCl), n-4 (NK Dox), and n-3 (AP Dox. NK NaCl, DR Dox, DR + NaCl). Statistical differences were determined using an ordinary 1-way ANOVA with Tukey's post-hoc test comparing each venom group within itself and to the doxycycline only control (**** P  < .0001). (*** P  < .001), (** P  < .01). (* P  < .05). Open in new tab Download slide Conclusion Doxycycline reduced PLA2- and SVMP-related lethality, particularly in A. piscivorus envenomings and in a limited capacity with D. russelii revealing its promise as a treatment for snakebites. In addition, CK activity, a common indicator of muscle damage was inhibited in mice that received doxycycline-treated venom. The doxycycline concentrations identified in the ED50 studies correspond to 1,456 to 5,061 mg dosages for a 70 kg human. Factors including venom yield and snake species would affect the actual dosage needed. Studies into high-dose doxycycline safety and its effectiveness against several snake species is needed to fully translate its use into humans. Based on this work, doxycycline could be used as a treatment en route to higher echelons of care, providing protection from muscle damage and reducing lethality in different snake species. [ABSTRACT FROM AUTHOR]

Every year, according to the World Health Organization, nearly 5,000,000 million accidents due to snake bites are reported worldwide, of which it is estimated that 33.3% to 50% of cases present as poisoning. Ophidic accidents that include ophidiotoxicosis have care protocols of therapy with antivenom serums, which vary according to the genus and species of the snake. Although in Colombia there are protocols for the care of ophidiotoxicosis in humans described by health entities, the canine clinic lacks this information. The aim of this systematic review is to build a medical protocol for ophidiotoxicosis in canines based on information reported in Colombia or tropical countries with which similar venomous snakes are shared. For this action, the PRISMA protocol was used; in total, 57 articles and 10 official documents on protocols for the care of ophidic accidents in humans were reviewed, which allowed the possible to classify snakebite accidents in group 1 (Bothrops, Lachesis and Crotalus accidents) and group 2 (Micrurus accident), also establish a medical protocol for ophidiotoxicosis in each of the groups indicated in canines, depending on the severity of the clinical and paraclinical condition. In conclusion, the clinical and paraclinical signs of the canine, vasculotoxic or neurotoxic, allow us to identify the group to which the aggressor snake belongs (group 1 or group 2, respectively), and their severity guides the selection and dosage of antivenom therapy specific for the clinical management of ophidiotoxicosis in canines. [ABSTRACT FROM AUTHOR]

Over 32,000 individuals succumb to snake envenoming in sub-Saharan Africa (sSA) annually. This results from several factors, including a lack of antivenom products capable of neutralising the venoms of diverse snake species in this region. Most manufacturers produce polyvalent antivenoms targeting 3 to 16 clinically important snake species in sSA. However, specific products are unavailable for many others, especially those with a restricted geographic distribution. While next-generation antivenoms, comprising a cocktail of broadly neutralising antibodies, may offer an effective solution to this problem, given the need for their clinical validation, recombinant antivenoms are far from being available to snakebite victims. One of the strategies that could immediately address this issue involves harnessing the cross-neutralisation potential of existing products. Therefore, we assessed the neutralisation potency of PANAF-Premium antivenom towards the venoms of 14 medically important snakes from 13 countries across sSA for which specific antivenom products are unavailable. Preclinical assays in a murine model of snake envenoming revealed that the venoms of most snake species under investigation were effectively neutralised by this antivenom. Thus, this finding highlights the potential use of PANAF-Premium antivenom in treating bites from diverse snakes across sSA and the utility of harnessing the cross-neutralisation potential of antivenoms. [ABSTRACT FROM AUTHOR]

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

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. [ABSTRACT FROM AUTHOR]

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 (K i < 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. [Display omitted] • A total of 197 peptides were identified in the venom of Bothrops cotiara. • A novel peptide is an angiotensin converting enzyme inhibitor. • This peptide inhibitor is a fragment of a snake venom metalloproteinase. [ABSTRACT FROM AUTHOR]

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Background: Infections caused by multi-drug resistance (MDR) strains are potentially fatal public health issues worldwide that need pressing attention. Previous reports suggested using snake venom fractions as an effective alternative mechanism to the already available antibacterial drugs. In this study, we conducted a systematic review to analyze the bactericidal effects of snake venom phospholipases (PLA2s). Methods: From the beginning through 30 March 2022, we searched the PubMed and Embase databases in accordance with the most recent PRISMA recommendations. We also conducted a manual search to identify relevant reports to improve literature coverage. Results: A total of 24 studies were included based on the selection criteria to compile this review. Of them, 16 studies were obtained from the abovementioned databases and eight through manual searches. The other 8 studies were obtained through the references of the included studies. According to the review, we reported that some PLA2s showed more vigorous bactericidal activity on some Gram-negative and a moderate effect on Gram-negative and Gram-positive. Furthermore, we reported that the presence of p-bromophenacyl bromide (p-BPP) showed a significant decrease in enzymatic and associated antibacterial activities. Moreover, we observed that about 80% of the PLA2s reported in our systematic review study were those from the Viperidae family, whereas 20% came from the Elapidae family. Moreover, some variations were revealed in the current study regarding the mechanism of actions of the snake venom PLA2s (svPLA2s). Conclusion: This systematic review provides a comprehensive overview of the bactericidal effect of snake venom PLA2s and the analysis of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PLA2s for bacterial strains. Varying bactericidal effects from various snake species and South American rattlesnakes were reported, presenting compelling concepts to the alternative search for therapies against bacterial resistance. Thus, further analysis of the bactericidal effects of other snake venoms PLA2s considering different strains is needed. Moreover, more data are needed to investigate other bacteria of public health priority using peptides and other purified snake toxins.

Introduction. The performed research focused on a search for new biologically active compounds acting on blood coagulation system proteins and cells. To achieve this goal, we fractionated Vipera berus berus snake venom and studied the action of the separated fractions on human blood plasma, fibrinogen, platelets or red cells. Methods. Crude venom was fractionated using ion-exchange chromatography. Protein composition of fractions was studied using SDS-PAGE. The ability of fractions to prolong or initiate blood plasma clotting was studied using the prothrombin time test with thromboplastin. Fibrinogen-specific proteases were detected using enzyme-electrophoresis. Action on red cells was estimated using the hemolysis test. Aggregometry was used for the detection of action on platelets. All experiments in this study were performed in vitro. Results. We obtained fractions containing phospholipase and a protease that is able to hydrolyze fibrinogen, leading to the loss of its ability to polymerize and to maintain platelet aggregation. Conclusion. Further purification and study of these components can be a promising research direction for biotechnological as well as for biomedical use.

From the venom of the Bothrops pictus snake, an endemic species from Peru, we recently have described toxins that inhibited platelet aggregation and cancer cell migration. In this work, we characterize a novel P-III class snake venom metalloproteinase, called pictolysin-III (Pic-III). It is a 62 kDa proteinase that hydrolyzes dimethyl casein, azocasein, gelatin, fibrinogen, and fibrin. The cations Mg2+ and Ca2+ enhanced its enzymatic activity, whereas Zn2+ inhibited it. In addition, EDTA and marimastat were also effective inhibitors. The amino acid sequence deduced from cDNA shows a multidomain structure that includes a proprotein, metalloproteinase, disintegrin-like, and cysteine-rich domains. Additionally, Pic-III reduces the convulxin- and thrombin-stimulated platelet aggregation and in vivo, it has hemorrhagic activity (DHM = 0.3 µg). In epithelial cell lines (MDA-MB-231 and Caco-2) and RMF-621 fibroblast, it triggers morphological changes that are accompanied by a decrease in mitochondrial respiration, glycolysis, and ATP levels, and an increase in NAD(P)H, mitochondrial ROS, and cytokine secretion. Moreover, Pic-III sensitizes to the cytotoxic BH3 mimetic drug ABT-199 (Venetoclax) in MDA-MB-231 cells. To our knowledge, Pic-III is the first SVMP reported with action on mitochondrial bioenergetics and may offer novel opportunities for promising lead compounds that inhibit platelet aggregation or ECM–cancer-cell interactions. [ABSTRACT FROM AUTHOR]

Quercetin derivatives have already shown their anti-inflammatory potential, inhibiting essential enzymes involved in this process. Among diverse pro-inflammatory toxins from snake venoms, phospholipase A2 is one of the most abundant in some species, such as Crotalus durissus terrificus and Bothrops jararacussu from the Viperidae family. These enzymes can induce the inflammatory process through hydrolysis at the sn-2 position of glycerophospholipids. Hence, elucidating the main residues involved in the biological effects of these macromolecules can help to identify potential compounds with inhibitory activity. In silico tools were used in this study to evaluate the potential of quercetin methylated derivatives in the inhibition of bothropstoxin I (BthTX-I) and II (BthTX-II) from Bothrops jararacussu and phospholipase A2 from Crotalus durissus terrificus. The use of a transitional analogous and two classical inhibitors of phospholipase A2 guided this work to find the role of residues involved in the phospholipid anchoring and the subsequent development of the inflammatory process. First, main cavities were studied, revealing the best regions to be inhibited by a compound. Focusing on these regions, molecular docking assays were made to show main interactions between each compound. Results reveal that analogue and inhibitors, Varespladib (Var) and p-bromophenacyl bromide (BPB), guided quercetins derivatives analysis, revealing that Leu2, Phe5, Tyr28, glycine in the calcium-binding loop, His48, Asp49 of BthTX-II and Cdtspla2 were the main residues to be inhibited. 3MQ exhibited great interaction with the active site, similar to Var results, while Q anchored better in the BthTX-II active site. However, strong interactions in the C-terminal region, highlighting His120, seem to be crucial to decreasing contacts with phospholipid and BthTX-II. Hence, quercetin derivatives anchor differently with each toxin and further in vitro and in vivo studies are essential to elucidate these data. [ABSTRACT FROM AUTHOR]

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.

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

Background: Infections caused by multi-drug resistance (MDR) strains are potentially fatal public health issues worldwide that need pressing attention. Previous reports suggested using snake venom fractions as an effective alternative mechanism to the already available antibacterial drugs. In this study, we conducted a systematic review to analyze the bactericidal effects of snake venom phospholipases (PLA2s). Methods: From the beginning through 30 March 2022, we searched the PubMed and Embase databases in accordance with the most recent PRISMA recommendations. We also conducted a manual search to identify relevant reports to improve literature coverage. Results: A total of 24 studies were included based on the selection criteria to compile this review. Of them, 16 studies were obtained from the abovementioned databases and eight through manual searches. The other 8 studies were obtained through the references of the included studies. According to the review, we reported that some PLA2s showed more vigorous bactericidal activity on some Gram-negative and a moderate effect on Gram-negative and Gram-positive. Furthermore, we reported that the presence of p-bromophenacyl bromide (p-BPP) showed a significant decrease in enzymatic and associated antibacterial activities. Moreover, we observed that about 80% of the PLA2s reported in our systematic review study were those from the Viperidae family, whereas 20% came from the Elapidae family. Moreover, some variations were revealed in the current study regarding the mechanism of actions of the snake venom PLA2s (svPLA2s). Conclusion: This systematic review provides a comprehensive overview of the bactericidal effect of snake venom PLA2s and the analysis of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PLA2s for bacterial strains. Varying bactericidal effects from various snake species and South American rattlesnakes were reported, presenting compelling concepts to the alternative search for therapies against bacterial resistance. Thus, further analysis of the bactericidal effects of other snake venoms PLA2s considering different strains is needed. Moreover, more data are needed to investigate other bacteria of public health priority using peptides and other purified snake toxins. [ABSTRACT FROM AUTHOR]

Simple Summary: A critical global health problem is microbial resistance to antibiotics. In order to further discuss this issue and search for practical means to overcome such problems, we reviewed the bibliography related to snake venoms, their proteins, and peptides with antimicrobial activity because many of them have the potential to become alternative antimicrobial agents or serve as lead compounds for the development of new ones. Among the proteins classified according to their structures are lectins, metalloproteinases, L-amino acid oxidases, phospholipases type A2, cysteine-rich secretory proteins, and serine proteinases. Among the oligopeptides are waprins, cardiotoxins, cathelicidins, and β-defensins. The list includes natural and synthetic small peptides, many derived from the proteins and the oligopeptides cited above. In vitro, all these snake-venom components are active against bacteria, fungi, parasites, and/or viruses pathogenic to humans. Some have also been tested in laboratory animals. In addition to organizing and discussing such an expressive amount of information, we propose here a multidisciplinary approach that includes sequence phylogeny as a way to better understand the relationship between amino-acid sequence and antimicrobial activity. This review focuses on proteins and peptides with antimicrobial activity because these biopolymers can be useful in the fight against infectious diseases and to overcome the critical problem of microbial resistance to antibiotics. In fact, snakes show the highest diversification among reptiles, surviving in various environments; their innate immunity is similar to mammals and the response of their plasma to bacteria and fungi has been explored mainly in ecological studies. Snake venoms are a rich source of components that have a variety of biological functions. Among them are proteins like lectins, metalloproteinases, serine proteinases, L-amino acid oxidases, phospholipases type A2, cysteine-rich secretory proteins, as well as many oligopeptides, such as waprins, cardiotoxins, cathelicidins, and β-defensins. In vitro, these biomolecules were shown to be active against bacteria, fungi, parasites, and viruses that are pathogenic to humans. Not only cathelicidins, but all other proteins and oligopeptides from snake venom have been proteolyzed to provide short antimicrobial peptides, or for use as templates for developing a variety of short unnatural sequences based on their structures. In addition to organizing and discussing an expressive amount of information, this review also describes new β-defensin sequences of Sistrurus miliarius that can lead to novel peptide-based antimicrobial agents, using a multidisciplinary approach that includes sequence phylogeny. [ABSTRACT FROM AUTHOR]

Snakebite envenomation (SBE) is a neglected tropical disease (NTD) with an approximate 1.8 million cases annually. The tremendous figure is concerning, and the currently available treatment for snakebite envenomation is antivenom. However, the current antivenom has limited cross-neutralisation activity due to the variations in snake venom composition across species and geographical locations. The proteomics of medically important venomous species is essential as they study the venom compositions within and among different species. The advancement of sophisticated proteomic approaches allows intensive investigation of snake venoms. Nevertheless, there is a need to consolidate the venom proteomics profiles and distribution analysis to examine their variability patterns. This review systematically analysed the proteomics and toxicity profiles of medically important venomous species from Asia across different geographical locations. An interactive dashboard - Asiatic Proteomics Interactive Datasets was curated to consolidate the distribution patterns of the venom compositions, serve as a comprehensive directory for large-scale comparative meta-analyses. The population proteomics demonstrate higher diversities in the predominant venom toxins. Besides, inter-regional differences were also observed in Bungarus sp., Naja sp., Calliophis sp., and Ophiophagus hannah venoms. The elapid venoms are predominated with three-finger toxins (3FTX s) and phospholipase A 2 (PLA 2). Intra-regional variation is only significantly observed in Naja naja venoms. Proteomics diversity is more prominent in viper venoms, with widespread dominance observed in snake venom metalloproteinase (SVMP) and snake venom serine protease (SVSP). Correlations exist between the proteomics profiles and the toxicity (LD 50) of the medically important venomous species. Additionally, the predominant toxins, alongside their pathophysiological effects, were highlighted and discussed as well. The insights of interactive toxico-proteomics datasets provide comprehensive frameworks of venom dynamics and contribute to developing antivenoms for snakebite envenomation. This could reduce misdiagnosis of SBE and accelerate the researchers' data mining process. [Display omitted] • Interactive Asiatic Snake Venom Proteomics Dataset was curated and consolidated. • Inter and intra-regional specific venom variations were observed and affects antivenom efficacy. • There are correlations between venom proteomics profile and pathophysiology outcomes. • The comprehensive analysis of venom proteomics contributes to snakebite management. [ABSTRACT FROM AUTHOR]

Bothrops spp. envenomation and its relationship with ischemic stroke has complex pathogenesis. Local effects such as edema, pain, redness, necrosis, and systemic manifestations like coagulation disorders, thrombosis, renal failure, and hemorrhage have been reported. Hemorrhagic stroke is a common neurological complication but ischemic stroke is poorly understood. We present here the case of a 50-year-old male with no comorbidities referred from a rural area in southwest Colombia with a Bothrops spp. snakebite on the left hand. On admission, the patient presented with a deterioration of consciousness and required mechanical ventilation assistance. The MRI showed multiple ischemic areas in the bilateral frontaltemporal and occipital regions. Two months later, the patient had a favorable resolution, although central paresis in the III and VI cranial nerves and positive Babinski’s sign persisted. As already mentioned, the pathophysiology of ischemic stroke due to snakebite is complex but the procoagulant activity of the venom components, the hypovolemic shock, the endothelial damage, and the thromboinflammation can explain it, and although it rarely occurs, it should be considered as a complication of ophidian accidents caused by Bothrops spp.

PURPOSE: To evaluate whether reduction in glioblastoma radiation treatment volume can reduce risk of acute severe lymphopenia (ASL). METHODS AND MATERIALS: A total of 210 patients with supratentorial/nonmetastatic glioblastoma were treated with radiation therapy (RT) plus temozolomide from 2007 to 2016 and had laboratory data on total lymphocyte counts. Before 2015, 164 patients were treated with standard-field RT (SFRT), and limited-field RT (LFRT) was implemented thereafter for 46 patients to reduce treatment volume. Total lymphocyte counts were evaluated at baseline, during RT, and at approximately week 12 from initiating RT. Acute severe lymphopenia was defined as any total lymphocyte count < 500 cells/μL within 3 months (by week 12) of initiating RT. Multivariate analysis for overall survival (OS) was performed with Cox regression and with logistic regression for ASL. Propensity score matching was performed to adjust for variability between cohorts. Acute severe lymphopenia, progression-free survival (PFS), and OS were compared using the Kaplan-Meier method. RESULTS: Limited-field RT patients had higher gross tumor volume than SFRT patients yet lower brain dose-volume parameters, including volume receiving 25 Gy (V25 Gy: 41% vs 53%, respectively, P

Among the medically most important snakes in the world, the species belonging to the genus Daboia have been attributed to the highest number of human envenomings, deaths and disabilities. Given their significant clinical relevance, the venoms of Russell's vipers (D. russelii and D. siamensis) have been the primary focus of research. In contrast, the composition, activity, ecology and evolution of venom of its congener, the Palestine viper (D. palaestinae), have remained largely understudied. Therefore, to unravel the factors responsible for the enhanced medical relevance of D. russelii in comparison to D. palaestinae, we comparatively evaluated their venom proteomes, biochemical activities, and mortality and morbidity inflicting potentials. Furthermore, the synthesis and regulation of venom in snakes have also remained underinvestigated, and the relative contribution of each venom gland remains unclear. We address this knowledge gap by sequencing the tissue transcriptomes of both venom glands of D. palaestinae, and comparatively evaluating their contribution to the secreted venom concoction. Our findings highlight the disparity in the venom composition, function and toxicities of the two Daboia species. We also show that toxin production is not partitioned between the two venom glands of D. palaestinae. [ABSTRACT FROM AUTHOR]

Longitudinal metabolomics and lipidomics analyses were carried out on the blood plasma of mice injected intramuscularly with venoms of the viperid species Bothrops asper or Daboia russelii. Blood samples were collected 1, 3, 6, and 24 h after venom injection, and a control group of non-envenomed mice was included. Significant perturbations in metabolomics and lipidomics were observed at 1, 3, and 6 h, while values returned close to those of control mice by 24 h, hence reflecting a transient pattern of metabolic disturbance. Both venoms induced significant changes in amino acids, as well as in several purines and pyrimidines, and in some metabolites of the tricarboxylic acid cycle. KEGG analysis of metabolic pathways that showed those with the greatest change included aminoacyl tRNA synthesis and amino acid biosynthesis and metabolism pathways. With regard to lipid metabolism, there was an increase in triglycerides and some acyl carnitines and a concomitant drop in the levels of some phospholipids. In addition, envenomed mice had higher levels of cortisol, heme, and some oxidative stress markers. The overall pattern of metabolic changes in envenomed mice bears similarities with the patterns described in several traumatic injuries, thus underscoring a metabolic response/adaptation to the injurious action of the venoms. [ABSTRACT FROM AUTHOR]

Snake envenomation poses significant medical challenges, particularly in subtropical and tropical regions, with long-term impacts on neurovascular integrity and neuroinflammation remaining underexplored. This study investigates the effects of venom from four species of venomous snakes in southern China-Zhoushan Cobra (Naja atra, NA), Many-banded Krait (Bungarus multicinctus, BM), Five-paced Pit Viper (Deinagkistrodon acutus, DA), and Chinese Moccasin (Protobothrops mucrosquamatus, PM) - on the blood-brain barrier (BBB) and chronic neuroinflammation. Using mass spectrometry, we analyzed venom protein compositions, while cytotoxic effects on mouse brain endothelial cells (bEND.3) were evaluated to determine IC 50 values. In vitro BBB models and in vivo experiments in C57BL/6J mice revealed that NA venom, in particular, significantly compromised BBB integrity without inducing large-scale apoptosis, leading to persistent BBB disruption characterized by increased permeability and selective degradation of extracellular matrix and tight junction proteins. Moreover, to simulate secondary infections that often occur following snakebites, we combined venom exposure with lipopolysaccharide (LPS) treatment, which exacerbated neuroinflammatory responses by intensifying microglial activation and promoting a pro-inflammatory phenotype. These findings highlight the role of snake venom in compromising neurovascular integrity and promoting vulnerability to chronic neuroinflammation, emphasizing the need for further research into venom-induced neuroinflammatory pathways and their potential as therapeutic targets., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Snakebite is a medical emergency that often leads to high mortality and morbidity in tropical and subtropical regions. The diversity in venom composition between various types of snakes necessitates the use of different specific antivenom treatments, which presents clinical and financial challenges in the management of snakebites. Therefore, developing a broad-spectrum antidote to neutralize complex and diverse snake venoms has assumed critical importance. Herein, a broad-spectrum antidote is developed through molecular recognition and coassembly to neutralize four kinds of snake venom toxins, those are three-finger toxin (3FTx), snake venom metalloproteinase (SVMP), phospholipase A 2 (PLA 2 ), and snake venom serine protease (SVSP), which have high abundance and toxicity. The coassembly of sulfonate-modified amphiphilic calixarene (SCA) and amphiphilic cyclodextrin (CD) is employed to neutralize the toxicity of 3FTx, 1,2-dodecanedithiol (DDT) and thioetheramide phosphorylcholine (TEAPC) are introduced through coassembly to neutralize toxicity of SVMP and PLA 2 , respectively, and the nafamostat (NT), which can be loaded through the host-guest complexation, is employed to neutralize toxicity of SVSP. The broad-spectrum antidote, NT@SCA/CD/DDT/TEAPC, effectively neutralizes key toxins from the most medically important cobra and vipers, significantly improving survival rates of poisoned mice. This study conceptually validated the feasibility of broad-spectrum detoxification and also offers a conveniently integrated supramolecular strategy., (© 2024 Wiley‐VCH GmbH.)

In this work, we describe an easy, simple, and cost-effective method to assess the proteolytic activity of snake venoms. The method is based on measuring the hydrolytic halo formed by gelatin radial hydrolysis following the incubation of venoms on a solid gelatin-agarose plate. Venoms from Bothrops (B.) alternatus, B. diporus, B. neuwiedi, B. jararaca, B. jararacussu, Crotalus atrox, and Trimeresurus albolabris were tested. A dose-response relationship was observed for each venom tested, with proteolytic capacity values, determined as GD (gelatinolytic dose, the dose causing a 15 mm hydrolytic halo) ranging from 21 to 222 μg. A correlation between hydrolysis and hemorrhagic activity in rat skin (minimal hemorrhagic dose) was found, with an r 2 value of 0.8774 (p < 0.0001). The venoms' hydrolytic activity was significantly, though not completely, inhibited by EDTA. This methodology was also deployed to assess venom neutralization by antivenoms on the hydrolytic activity of the different venoms, demonstrating its usefulness in evaluating antivenom neutralizing capacity. The method presented is simple, cheap and useful for preliminary screening of venom proteolytic activity and its inhibition and may also predict gross differences in hemorrhagic activity, contributing to the reduction of the number of animals used for these determinations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Non-front-fanged snakes (NFFS) have long been overlooked by snake venom research, likely due to most of them being considered non-medically relevant for humans. The paucity of information about composition and activities of NFFS venoms and oral secretions makes it difficult to assess whether a given species can inflict medically significant bites. Here, we provide a review of the information currently available about the symptoms/signs elicited by bites from European NFFS, aiming to offer a foundation for understanding the threat they pose in terms of snakebite. Despite an overall limited amount of available data for most of the considered taxa, the genus Malpolon is notable for its capacity to cause local and systemic envenoming, including neurotoxic symptoms. Bites by other genera like, Hemorrhois, Hierophis, Natrix, Platyceps, Telescopus, and Zamenis are mainly associated with local symptoms, but the extent of their medical significance remains unclear. Our findings suggest that, although bites from European NFFS generally cause only mild effects, the potential occurrence of systemic effects from some species cannot be ruled out. Considering the above, any bite by European NFFS should receive professional medical evaluation in order to ensure patient safety and appropriate management, as well as detailed documentation facilitating construction of an accurate medical risk profile for the species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Colon polypectomy often involves managing bleeding, and the choice of hemostatic methods is critical for patient outcomes. This study addresses the hemostatic effects of lancehead snake venom thrombin compared to hemostatic forceps in the context of colon polypectomy., Objective: To compare and assess the effectiveness and safety of local application of lancehead snake venom thrombin and hemostatic forceps in achieving hemostasis during colon polypectomy., Design: A randomized controlled trial was conducted to investigate and compare the hemostatic outcomes of two different approaches in colon polypectomy., Setting: The study was conducted at the Affiliated Hospital of Hebei University Hospital from January 2022 to June 2022., Participants: A total of 80 patients with colon polyps who met the inclusion criteria were randomly assigned to either the lancehead snake venom thrombin group or the hemostatic forceps group., Interventions: In the hemostatic forceps group, hemostatic forceps were employed to seal the wound post-polyp resection. In the lancehead snake venom thrombin group, aluminium potassium sulfate gel, in conjunction with locally sprayed lancehead snake venom thrombin, was applied to the wound., Primary Outcome Measures: The study assessed (1) intraoperative immediate bleeding and hemostasis; (2) intraoperative hemostasis time; (3) postoperative delayed post-polypectomy bleeding (DPPB); and (4) adverse reactions as primary outcome measures., Results: No significant differences were observed in the incidence rate of intraoperative immediate bleeding and the success rate of intraoperative hemostasis between the two groups. The lancehead snake venom thrombin group exhibited a shorter intraoperative hemostasis time and a lower incidence rate of adverse reactions compared to the hemostatic forceps group. No significant difference was found in the incidence rate of postoperative DPPB between the two groups., Conclusion: Local application of lancehead snake venom thrombin proves to be more effective and safer than hemostatic forceps in promptly managing bleeding during colon polypectomy.

Despite the wide range of institutions that maintain venomous snakes in captivity in Brazil there are no comprehensive data on the occurrence of snakebites and envenomations in these places. We examined the range of native and exotic species of venomous snakes kept by Brazilian zoos and serpentaria (scientific and commercial) and assessed the frequency of snakebites in workers handling these snakes during a 10-year period (2012-2021). Twenty-two (73.3%) of 30 institutions returned a standard questionnaire, including 15 serpentaria and 7 zoos that together kept 10,607 venomous snakes in 2022/2023. Commercial and scientific serpentaria had many more snakes (n = 10,550, consisting of 10,499 native specimens and 51 exotic specimens) than zoos (n = 57 native specimens), with two genera accounting for the majority of native species (Bothrops spp. = 84.5% and Crotalus durissus ssp. = 13.5%). Thirty-seven snakebites were reported and involved primarily the hands (33), seven of which occurred during venom extraction and 30 in other circumstances, most of them while handling/manipulating the cages or snake boxes (10) and restraining (9) or feeding (5) the snake. In addition, there were two cases of venom accidently sprayed on the face, including the eyes. Most bites were caused by Bothrops spp. (31), followed by C. durissus ssp. (4), Lachesis muta (1) and Micrurus corallinus (1). Thirty-three bites (89.2%) were treated with antivenom, with four bites to the fingers by Bothrops spp. resulting in local functional sequelae. There were 366,918 venom extractions with a ratio of 1.9 bites/100,000 extractions; no bites were recorded in the six institutions that sedated the snakes prior to venom extraction, which accounted for 22.7% of all extractions. These findings show that although snakebites are rare in Brazilian zoos and serpentaria, severe envenomation may occur. The occurrence of snakebites could be reduced by measures such as sedation of the snakes before venom extraction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Snakebite envenomation is an important medical problem in numerous parts of the world causing about 2.7 million envenomations and between 81,000 and 138,000 deaths ayear. Antivenoms (AVs) are time proven effective therapeutics for snakebite envenomation. However, AVs, especially those against elapid neurotoxic venoms (cobras, kraits and mambas), are difficult to produce and are generally of low neutralizing potency. The most lethal component of most elapid venoms is the postsynaptic neurotoxins or the α-neurotoxins, which are responsible for death in most victims. It is generally believed that the low neutralizing potency of the AVs is due to the small molecular sizes, and thus the low immunogenicity, of the α-neurotoxins. Therefore, modifications of the toxins have been made to increase their size, and/or to detoxify them, hoping to improve the toxin's immunogenicity and AV potency. However, these maneuvers have not been applied to commercial AV production. The α-neurotoxins belong to a group of small proteins called three-finger toxins (3FTxs). The 3FTxs contain about 60–77 amino acid residues with four to five disulfide linkages and three anti-parallel β-sheets, which extend from a globular hydrophobic core resembling three fingers. The members of the 3FTxs exhibit a number of important pharmacological activities, e.g., inhibition of neuromuscular transmission and acetyl cholinesterase activities. Recent immunization experiments with a 26 amino acid peptide containing the consensus sequence of the α-neurotoxins, and a mixture of elapid α-neurotoxins using highly effective adjuvants and immunization protocols have resulted in neutralizing antibodies in rabbit and horse, respectively. In the present report using bioinformatics, we show that 23 3FTxs which include α-neurotoxins, cardiotoxins and non-conventional toxins, and the 26 amino acid peptide, were all predicted to contain high to medium score CD4 T-cell epitopes for human and mouse MHC IIs. This information corroborates the results obtained from animal experiments that the α-neurotoxins, in spite of their small sizes and toxicity, are in fact immunogenic. Thus, the uses of effective adjuvants and immunization procedures, rather than chemical/physical modifications of the toxin structures, are crucial to the production of potent AVs against elapid neurotoxic venoms. [Display omitted] • Four groups of snake 3-Finger toxins were subjected to NetMHCIIpan program for prediction of CD4 T epitopes. • These toxins and a peptide with α-neurotoxin sequence were predicted to contain high to medium affinity CD4 T epitopes. • These epitopes were mostly located on Loop II of 3FTx structures. • The findings corroborate previous experiments showing the α-neurotoxins and the peptide were immunogenic. [ABSTRACT FROM AUTHOR]

While molecular subtypes of glioblastoma (GBM) are defined using gene expression and mutation profiles, we identify a unique subpopulation based on addiction to the high-affinity glucose transporter, Glut3. Although Glut3 is a known driver of a cancer stem cell phenotype, direct targeting is complicated by its expression in neurons. Using established GBM lines and patient-derived stem cells, we identify a subset of tumors within the "proneural" and "classical" subtypes that are addicted to aberrant signaling from integrin αvβ3, which activates a PAK4-YAP/TAZ signaling axis to enhance Glut3 expression. This defined subpopulation of GBM is highly sensitive to agents that disrupt this pathway, including the integrin antagonist cilengitide, providing a targeted therapeutic strategy for this unique subset of GBM tumors.

Perioperative bleeding is a potentially devastating complication in neurosurgical patients, and plasma fibrinogen concentration has been identified as a potential modifiable risk factor for perioperative bleeding. The aim of this study was to evaluate preconditioning with Crotalus atrox venom (Cv-PC) as potential preventive therapy for reducing perioperative hemorrhage in the rodent model of surgical brain injury (SBI). C. atrox venom contains snake venom metalloproteinases that cleave fibrinogen into fibrin split products without inducing clotting. Separately, fibrinogen split products induce fibrinogen production, thereby elevating plasma fibrinogen levels. Thus, the hypothesis was that preconditioning with C. atrox venom will produce fibrinogen spilt products, thereby upregulating fibrinogen levels, ultimately improving perioperative hemostasis during SBI. We observed that Cv-PC SBI animals had significantly reduced intraoperative hemorrhage and postoperative hematoma volumes compared to those of vehicle preconditioned SBI animals. Cv-PC animals were also found to have higher levels of plasma fibrinogen at the time of surgery, with unchanged prothrombin time. Cv-PC studies with fractions of C. atrox venom suggest that snake venom metalloproteinases are largely responsible for the improved hemostasis by Cv-PC. Our findings indicate that Cv-PC increases plasma fibrinogen levels and may provide a promising therapy for reducing perioperative hemorrhage in elective surgeries.

From the venom of the Bothrops pictus snake, an endemic species from Peru, we recently have described toxins that inhibited platelet aggregation and cancer cell migration. In this work, we characterize a novel P-III class snake venom metalloproteinase, called pictolysin-III (Pic-III). It is a 62 kDa proteinase that hydrolyzes dimethyl casein, azocasein, gelatin, fibrinogen, and fibrin. The cations Mg2+ and Ca2+ enhanced its enzymatic activity, whereas Zn2+ inhibited it. In addition, EDTA and marimastat were also effective inhibitors. The amino acid sequence deduced from cDNA shows a multidomain structure that includes a proprotein, metalloproteinase, disintegrin-like, and cysteine-rich domains. Additionally, Pic-III reduces the convulxin- and thrombin-stimulated platelet aggregation and in vivo, it has hemorrhagic activity (DHM = 0.3 µg). In epithelial cell lines (MDA-MB-231 and Caco-2) and RMF-621 fibroblast, it triggers morphological changes that are accompanied by a decrease in mitochondrial respiration, glycolysis, and ATP levels, and an increase in NAD(P)H, mitochondrial ROS, and cytokine secretion. Moreover, Pic-III sensitizes to the cytotoxic BH3 mimetic drug ABT-199 (Venetoclax) in MDA-MB-231 cells. To our knowledge, Pic-III is the first SVMP reported with action on mitochondrial bioenergetics and may offer novel opportunities for promising lead compounds that inhibit platelet aggregation or ECM–cancer-cell interactions.

Quercetin derivatives have already shown their anti-inflammatory potential, inhibiting essential enzymes involved in this process. Among diverse pro-inflammatory toxins from snake venoms, phospholipase A2 is one of the most abundant in some species, such as Crotalus durissus terrificus and Bothrops jararacussu from the Viperidae family. These enzymes can induce the inflammatory process through hydrolysis at the sn-2 position of glycerophospholipids. Hence, elucidating the main residues involved in the biological effects of these macromolecules can help to identify potential compounds with inhibitory activity. In silico tools were used in this study to evaluate the potential of quercetin methylated derivatives in the inhibition of bothropstoxin I (BthTX-I) and II (BthTX-II) from Bothrops jararacussu and phospholipase A2 from Crotalus durissus terrificus. The use of a transitional analogous and two classical inhibitors of phospholipase A2 guided this work to find the role of residues involved in the phospholipid anchoring and the subsequent development of the inflammatory process. First, main cavities were studied, revealing the best regions to be inhibited by a compound. Focusing on these regions, molecular docking assays were made to show main interactions between each compound. Results reveal that analogue and inhibitors, Varespladib (Var) and p-bromophenacyl bromide (BPB), guided quercetins derivatives analysis, revealing that Leu2, Phe5, Tyr28, glycine in the calcium-binding loop, His48, Asp49 of BthTX-II and Cdtspla2 were the main residues to be inhibited. 3MQ exhibited great interaction with the active site, similar to Var results, while Q anchored better in the BthTX-II active site. However, strong interactions in the C-terminal region, highlighting His120, seem to be crucial to decreasing contacts with phospholipid and BthTX-II. Hence, quercetin derivatives anchor differently with each toxin and further in vitro and in vivo studies are essential to elucidate these data.

Snakebite envenomation is a neglected tropical disease that causes over 100,000 deaths each year. The only effective treatment consists of antivenoms derived from animal sera, but these have been deemed with highly variable potency and are usually inaccessible and too costly for victims. The production of antivenoms by venom-independent techniques, such as the immunization with multi-epitope constructs, could circumvent those drawbacks. Herein, we present a knowledge-based pipeline to prioritize potential epitopes of therapeutic relevance from toxins of medically important snakes in West Sub-Saharan Africa. It is mainly based on sequence conservation and protein structural features. The ultimately selected 41 epitopes originate from 11 out of 16 snake species considered of highest medical importance in the region and 3 out of 10 of those considered as secondary medical importance. Echis ocellatus, responsible for the highest casualties in the area, would be covered by 12 different epitopes. Remarkably, this pipeline is versatile and customizable for the analysis of snake venom sequences from any other region of the world. [ABSTRACT FROM AUTHOR]

Bothrops spp. envenomation and its relationship with ischemic stroke has complex pathogenesis. Local effects such as edema, pain, redness, necrosis, and systemic manifestations like coagulation disorders, thrombosis, renal failure, and hemorrhage have been reported. Hemorrhagic stroke is a common neurological complication but ischemic stroke is poorly understood. We present here the case of a 50-year-old male with no comorbidities referred from a rural area in southwest Colombia with a Bothrops spp. snakebite on the left hand. On admission, the patient presented with a deterioration of consciousness and required mechanical ventilation assistance. The MRI showed multiple ischemic areas in the bilateral frontaltemporal and occipital regions. Two months later, the patient had a favorable resolution, although central paresis in the III and VI cranial nerves and positive Babinski's sign persisted. As already mentioned, the pathophysiology of ischemic stroke due to snakebite is complex but the procoagulant activity of the venom components, the hypovolemic shock, the endothelial damage, and the thromboinflammation can explain it, and although it rarely occurs, it should be considered as a complication of ophidian accidents caused by Bothrops spp. [ABSTRACT FROM AUTHOR]

This review focuses on proteins and peptides with antimicrobial activity because these biopolymers can be useful in the fight against infectious diseases and to overcome the critical problem of microbial resistance to antibiotics. In fact, snakes show the highest diversification among reptiles, surviving in various environments; their innate immunity is similar to mammals and the response of their plasma to bacteria and fungi has been explored mainly in ecological studies. Snake venoms are a rich source of components that have a variety of biological functions. Among them are proteins like lectins, metalloproteinases, serine proteinases, L-amino acid oxidases, phospholipases type A2, cysteine-rich secretory proteins, as well as many oligopeptides, such as waprins, cardiotoxins, cathelicidins, and β-defensins. In vitro, these biomolecules were shown to be active against bacteria, fungi, parasites, and viruses that are pathogenic to humans. Not only cathelicidins, but all other proteins and oligopeptides from snake venom have been proteolyzed to provide short antimicrobial peptides, or for use as templates for developing a variety of short unnatural sequences based on their structures. In addition to organizing and discussing an expressive amount of information, this review also describes new β-defensin sequences of Sistrurus miliarius that can lead to novel peptide-based antimicrobial agents, using a multidisciplinary approach that includes sequence phylogeny.

Purpose: Glaucoma, one of the leading causes of irreversible blindness, is a common progressive optic neuropathy characterised by visual field defects and structural changes to the optic nerve head (ONH). There is extracellular matrix (ECM) accumulation and fibrosis of the lamina cribrosa (LC) in the ONH, and consequently increased tissue stiffness of the LC connective tissue. Integrins are cell surface proteins that provide the key molecular link connecting cells to the ECM and serve as bidirectional sensors transmitting signals between cells and their environment to promote cell adhesion, proliferation, and remodelling of the ECM. Here, we investigated the expression of αVβ3 integrin in glaucoma LC cell, and its effect on stiffness-induced ECM gene transcription and cellular proliferation rate in normal (NLC) and glaucoma (GLC) LC cells, by down-regulating αVβ3 integrin expression using cilengitide (a known potent αVβ3 and αVβ5 inhibitor) and β3 integrin siRNA knockdown. Methods: GLC cells were compared to age-matched controls NLC to determine differential expression levels of αVβ3 integrin, ECM genes (Col1A1, α-SMA, fibronectin, vitronectin), and proliferation rates. The effects of αVβ3 integrin blockade (with cilengitide) and silencing (with a pool of four predesigned αVβ3 integrin siRNAs) on ECM gene expression and proliferation rates were evaluated using both reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting in the human NLC cells cultured on soft (4 kPa) and stiff (100 kPa) substrate and in GLC cells grown on standard plastic plates. Results: αVβ3 integrin gene and protein expression were enhanced ( p < 0.05) in GLC cells as compared to NLC. Both cilengitide and siRNA significantly reduced αVβ3 expression in GLC. When NLC were grown in the stiff substrate, cilengitide and siRNA also significantly reduced the increased expression in αVβ3, ECM components, and proliferation rate. Conclusions: Here, we provide evidence of cilengitide- and siRNA-mediated silencing of αVβ3 integrin expression, and inhibition of ECM synthesis in LC cells. Therefore, αVβ3 integrin may be a promising target for the development of novel anti-fibrotic therapies for treating the LC cupping of the ONH in glaucoma.

HER2-positive breast cancer, representing 15-20% of all breast cancer cases, often develops resistance to the HER2-targeted therapy trastuzumab. Unfortunately, effective treatments for advanced HER2-positive breast cancer remain scarce. This study aims to investigate the roles of ITGβ3, and Hedgehog signaling in trastuzumab resistance and explore the potential of combining trastuzumab with cilengitide as a therapeutic strategy. Quantitative gene expression analysis was performed to assess the transcription of EMT (epithelial-mesenchymal transition) markers Slug , Snail , Twist2 , and Zeb1 in trastuzumab-resistant HER2-positive breast cancer cells. The effects of ITGβ3 and Hedgehog signaling were investigated. Additionally, the combination therapy of trastuzumab and cilengitide was evaluated. Acquired trastuzumab resistance induced the transcription of Slug , Snail , Twist2 , and Zeb1 , indicating increased EMT. This increased EMT was mediated by ITGB3 and Hedgehog signaling. ITGβ3 regulated both the Hedgehog pathway and EMT, with the latter being independent of the Hedgehog pathway. The combination of trastuzumab and cilengitide showed a synergistic effect, reducing both EMT and Hedgehog pathway activity. Targeting ITGβ3 with cilengitide, combined with trastuzumab, effectively suppresses the Hedgehog pathway and EMT, offering a potential strategy to overcome trastuzumab resistance and improve outcomes for HER2-positive breast cancer patients.

Background: Snakebite is a global environmental and occupational hazard and a significant public health threat. In rural areas, snakebite cases often go unreported and undocumented due to the lack of access to well-structured healthcare facilities/infrastructure. In some cases, the need for antisnake venom (ASV) far outstrips supply, negatively affecting treatment outcomes. This study, therefore, assessed the epidemiological characteristics of snakebite cases, their management, and how antivenoms are utilised at the selected hospital in the Jasikan District Hospital. Methods: A 6-year retrospective study using secondary data from antivenom return forms (pharmacy records), clinical records (patient folders), the District Health Information Management System-2 (DHIMS-2) database, and consulting room registers was carried out in selected hospitals in the Jasikan District, Oti, Ghana. Results: The predominant symptom of snakebite was localised pain (71.4%). The snakebite commonly occurred at home (19%) and on farms (18%). Of the 98 snakebite cases, ASV was administered to 73 (74.5%) cases. Supportive treatment applied included prophylactic antitetanus immunoglobulin (ATS) (80.6%), prophylactic antibiotics (63%), corticosteroids (80.6%), and analgesics (63%). 95% ( n = 94) of complete recoveries were recorded; three were discharged against medical advice, and one was mortality. The supply and use of antivenom were erratic throughout the months of high incidence, partly due to inconsistent availability at the Regional Medical Stores. The average ASV vials and hospital stay duration were 1.23 ± 0.86 vials and 2.67 ± 1.97 days, respectively. Although the peak of snakebites occurs in April, May, and June, the demand for antivenom in April and May exceeded supply. Conclusion: The outcome of most snakebite case management was appropriate, irrespective of inadequate ASV supply in certain months. The erratic antivenom supply should be aligned with seasonal and facility-use patterns to enhance regional snakebite management., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Courage Edem Ketor et al.)

As expected, several new variants of Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-CoV-2) emerged and have been detected around the world throughout this Coronavirus Disease of 2019 (COVID-19) pandemic. Currently, there is no specific developed drug against COVID-19 and the challenge of developing effective antiviral strategies based on natural agents with different mechanisms of action becomes an urgent need and requires identification of genetic differences among variants. Such data is used to improve therapeutics to combat SARS-CoV-2 variants. Nature is known to offer many biotherapeutics from animal venoms, algae and plant that have been historically used in traditional medicine. Among these bioresources, snake venom displays many bioactivities of interest such as antiviral, antiplatelet, antithrombotic, anti-inflammatory, antimicrobial and antitumoral. COVID-19 is a viral respiratory sickness due to SARS-CoV-2 which induces thrombotic disorders due to cytokine storm, platelet hyperactivation and endothelial dysfunction. This review aims to: (1) present an overview on the infection, the developed thrombo-inflammatory responses and mechanisms of induced thrombosis of COVID-19 compared to other similar pathogenesis; (2) underline the role of natural compounds such as anticoagulant, antiplatelet and thrombolytic agents; (3) investigate the management of coagulopathy related to COVID-19 and provide insight on therapeutic such as venom compounds. We also summarize the updated advances on antiviral proteins and peptides derived from snake venoms that could weaken coagulopathy characterizing COVID-19. [ABSTRACT FROM AUTHOR]

PurposeFit-for-purpose pharmacodynamic biomarkers could expedite development of combination antiangiogenic regimens. Plasma sVEGFR2 concentrations ([sVEGFR2]) mark sunitinib effects on the systemic vasculature. We hypothesized that cilengitide would impair microvasculature recovery during sunitinib withdrawal and could be detected through changes in [sVEGFR2].Experimental designAdvanced solid tumor patients received 50 mg sunitinib daily for 14 days. For the next 14 days, patients were randomized to arm A (cilengitide 2,000 mg administered intravenously twice weekly) or arm B (no treatment). The primary endpoint was change in [sVEGFR2] between days 14 and 28. A candidate pharmacodynamic biomarker of cilengitide inhibition of integrin αvβ3, serum c-telopeptide collagen crosslinks (CTx), was also measured.ResultsOf 21 patients, 14 (7 per arm) received all treatments without interruption and had all blood samples available for analysis. The mean change and SD of [sVEGFR2] for all sunitinib-treated patients was consistent with previous data. There was no significant difference in the mean change in [sVEGFR2] from days 14 to 28 between the arms [arm A: 2.8 ng/mL; 95% confidence interval (CI), 2.1-3.6 vs. arm B: 2.0 ng/mL; 95% CI, 0.72-3.4; P = 0.22, 2-sample t test]. Additional analyses suggested (i) prior bevacizumab therapy to be associated with unusually low baseline [sVEGFR2] and (ii) sunitinib causes measurable changes in CTx.ConclusionsCilengitide had no measurable effects on any circulating biomarkers. Sunitinib caused measurable declines in serum CTx. The properties of [sVEGFR2] and CTx observed in this study inform the design of future combination antiangiogenic therapy trials.

The research and development of alternative treatments for snakebites (e.g., medicinal plants) is necessary due to the high costs of the existing ones. The effects of the aqueous extracts from Jacaranda decurrens leaves, roots, and xylopodium were analyzed upon the venom-induced (Bothrops spp. and Crotalus spp.) systemic and local toxicity. The extracts were able to partially inhibit the phospholipase activity of the venoms from Bothrops jararacussu and Crotalus durissus terrificus. The myotoxic, edema-inducing, coagulant, and hemorrhagic activities were also inhibited. The SDS-PAGE showed that the venom proteins were intact after their incubation with the extracts. This suggests that the possible mechanism of inhibition is not related to the degradation of the protein but rather to their binding to specific sites of the enzymes. The extracts significantly prolonged the survival time of animals in the lethality assay performed with Crotalus durissus terrificus venom and its toxin (crotoxin). The anti-ophidic activity of medicinal plants may aid in the management of snakebites in distant locations by reducing the victim’s local effects and time to heal.

Among the medically most important snakes in the world, the species belonging to the genus Daboia have been attributed to the highest number of human envenomings, deaths and disabilities. Given their significant clinical relevance, the venoms of Russell’s vipers (D. russelii and D. siamensis) have been the primary focus of research. In contrast, the composition, activity, ecology and evolution of venom of its congener, the Palestine viper (D. palaestinae), have remained largely understudied. Therefore, to unravel the factors responsible for the enhanced medical relevance of D. russelii in comparison to D. palaestinae, we comparatively evaluated their venom proteomes, biochemical activities, and mortality and morbidity inflicting potentials. Furthermore, the synthesis and regulation of venom in snakes have also remained underinvestigated, and the relative contribution of each venom gland remains unclear. We address this knowledge gap by sequencing the tissue transcriptomes of both venom glands of D. palaestinae, and comparatively evaluating their contribution to the secreted venom concoction. Our findings highlight the disparity in the venom composition, function and toxicities of the two Daboia species. We also show that toxin production is not partitioned between the two venom glands of D. palaestinae.

Snakebite envenoming is the cause of an ongoing health crisis in several regions of the world, particularly in tropical and neotropical countries. This scenario creates an urgent necessity for new practical solutions to address the limitations of current therapies. The current study investigated the isolation, phytochemical characterization, and myotoxicity inhibition mechanism of gallic acid (GA), a myotoxin inhibitor obtained from Anacardium humile. The identification and isolation of GA was achieved by employing analytical chromatographic separation, which exhibited a compound with retention time and nuclear magnetic resonance spectra compatible with GA's commercial standard and data from the literature. GA alone was able to inhibit the myotoxic activity induced by the crude venom of Bothrops jararacussu and its two main myotoxins, BthTX-I and BthTX-II. Circular dichroism (CD), fluorescence spectroscopy (FS), dynamic light scattering (DLS), and interaction studies by molecular docking suggested that GA forms a complex with BthTX-I and II. Surface plasmon resonance (SPR) kinetics assays showed that GA has a high affinity for BthTX-I with a K D of 9.146 × 10−7 M. Taken together, the two-state reaction mode of GA binding to BthTX-I, and CD, FS and DLS assays, suggest that GA is able to induce oligomerization and secondary structure changes for BthTX-I and -II. GA and other tannins have been shown to be effective inhibitors of snake venoms' toxic effects, and herein we demonstrated GA's ability to bind to and inhibit a snake venom PLA 2 , thus proposing a new mechanism of PLA 2 inhibition, and presenting more evidence of GA's potential as an antivenom compound. [ABSTRACT FROM AUTHOR]