Comparison of Preclinical Properties of Several Available Antivenoms in the Search for Effective Treatment of Vipera ammodytes and Vipera berus Envenoming

Suspected envenomation by the common European adder (Vipera berus berus) in 28 horses in Finland

Vipera berus berus is the only venomous snake present in the Nordic countries and cases of envenomation in horses are reported during the warmer months. Little is known about the presentation, treatment and survival of horses with common European adder envenomation. Clinical and laboratory findings, treatment and outcome are reported for 28 horses admitted to Helsinki University Equine Hospital in 2008-2023 due to suspicion of snake bite. Eleven of these horses received antivenom treatment. Other common treatments included non-steroidal anti-inflammatories (22/28), antimicrobials (19/28), intravenous fluid therapy (11/28), corticosteroids (9/28) and local treatment (11/28). All horses survived until discharge. No difference was detected in the length of hospital stay between horses with moderate envenomation that had or had not received antivenom treatment. Horses with moderate envenomation are more likely to receive antivenom treatment and require longer hospital stay than horses with mild envenomation. Antivenom treatment is not associated with shorter hospital stay. Little evidence supports the use of corticosteroids and antibiotics in treatment of envenomation. Studies with larger numbers of animals are warranted to evaluate the effect of treatment, including administration of antivenom, on long-term outcome and survival from envenomation.

Being Stung Once or Twice by Bees (Apis mellifera L.) Slightly Disturbed the Serum Metabolome of SD Rats to a Similar Extent

In most cases, the number of honeybee stings received by the body is generally small, but honeybee stings can still cause serious allergic reactions. This study fully simulated bee stings under natural conditions and used 1H Nuclear Magnetic Resonance (1H NMR) to analyze the changes in the serum metabolome of Sprague-Dawley (SD) rats stung once or twice by honeybees to verify the impact of this mild sting on the body and its underlying mechanism. The differentially abundant metabolites between the blank control rats and the rats stung by honeybees included four amino acids (aspartate, glutamate, glutamine, and valine) and four organic acids (ascorbic acid, lactate, malate, and pyruvate). There was no separation between the sting groups, indicating that the impact of stinging once or twice on the serum metabolome was similar. Using the Principal Component Discriminant Analysis ( PCA-DA) and Variable Importance in Projection (VIP) methods, glucose, lactate, and pyruvate were identified to help distinguish between sting groups and non-sting groups. Metabolic pathway analysis revealed that four metabolic pathways, namely, the tricarboxylic acid cycle, pyruvate metabolism, glutamate metabolism, and alanine, aspartate, and glutamate metabolism, were significantly affected by bee stings. The above results can provide a theoretical basis for future epidemiological studies of bee stings and medical treatment of patients stung by honeybees.

An agonist of CXCR4 induces a rapid recovery from the neurotoxic effects of Vipera ammodytes and Vipera aspis venoms

People bitten by Alpine vipers are usually treated with antivenom antisera to prevent the noxious consequences caused by the injected venom. However, this treatment suffers from a number of drawbacks and additional therapies are necessary. The venoms of Vipera ammodytes and of Vipera aspis are neurotoxic and cause muscle paralysis by inducing neurodegeneration of motor axon terminals because they contain a presynaptic acting sPLA2 neurotoxin. We have recently found that any type of damage to motor axons is followed by the expression and activation of the intercellular signaling axis consisting of the CXCR4 receptor present on the membrane of the axon stump and of its ligand, the chemokine CXCL12 released by activated terminal Schwann cells. We show here that also V. ammodytes and V. aspis venoms cause the expression of the CXCL12-CXCR4 axis. We also show that a small molecule agonist of CXCR4, dubbed NUCC-390, induces a rapid regeneration of the motor axon terminal with functional recovery of the neuromuscular junction. These findings qualify NUCC-390 as a promising novel therapeutics capable of improving the recovery from the paralysis caused by the snakebite of the two neurotoxic Alpine vipers.

Global parameter optimisation and sensitivity analysis of antivenom pharmacokinetics and pharmacodynamics

In recent years it has become possible to design snakebite antivenoms with diverse pharmacokinetic properties. Owing to the pharmacokinetic variability of venoms, the choice of antivenom scaffold may influence a treatment's neutralisation coverage. Computation offers a useful medium through which to assess the pharmacokinetics and pharmacodynamics of envenomation-treatment systems, as antivenoms with identical neutralising capacities can be simulated. In this study, we simulate envenomation and treatment with a variety of antivenoms, to define the properties of effective antivenoms. Systemic envenomation and treatment were described using a two-compartment pharmacokinetic model. Treatment of Naja sumatrana and Cryptelytrops purpureomaculatus envenomation was simulated with a set of 200,000 theoretical antivenoms across 10 treatment time delays. These two venoms are well-characterised and have differing pharmacokinetic properties. The theoretical antivenom set varied across molecular weight, dose, kon, koff, and valency. The best and worst treatments were identified using an area under the curve metric, and a global sensitivity analysis was performed to quantify the influence of the input parameters on treatment outcome. The simulations show that scaffolds of diverse molecular formats can be effective. Molecular weight and valency have a negligible direct impact on treatment outcome, however low molecular weight scaffolds offer more flexibility across the other design parameters, particularly when treatment is delayed. The simulations show kon to primarily mediate treatment efficacy, with rates above 105 M-1s-1 required for the most effective treatments. koff has the greatest impact on the performance of less effective scaffolds. While the same scaffold preferences for improved treatment are seen for both model snakes, the parameter bounds for C. purpureomaculatus envenomation are more constrained. This paper establishes a computational framework for the optimisation of antivenom design.

Biochemistry and toxicology of proteins and peptides purified from the venom of Vipera berus berus

The isolation and characterization of individual snake venom components is important for a deeper understanding of the pathophysiology of envenomation and for improving the therapeutic procedures of patients. It also opens possibilities for the discovery of novel toxins that might be useful as tools for understanding cellular and molecular processes. The variable venom composition, toxicological and immunological properties of the common vipers (Vipera berus berus) have been reviewed. The combination of venom gland transcriptomics, bottom-up and top-down proteomics enabled comparison of common viper venom proteomes from multiple individuals. V. b. berus venom contains proteins and peptides belonging to 10–15 toxin families: snake venom metalloproteinase, phospholipases A₂ (PLA₂), snake venom serine proteinase, aspartic protease, L-amino acid oxidase (LAAO), hyaluronidase, 5′-nucleotidase, glutaminyl-peptide cyclotransferase, disintegrin, C-type lectin (snaclec), nerve growth factor, Kunitz type serine protease inhibitor, snake venom vascular endothelial growth factor, cysteine-rich secretory protein, bradykinin potentiating peptide, natriuretic peptides. PLA₂ and LAAO from V. b. berus venom produce more pronounced cytotoxic effects in cancer cells than normal cells, via induction of apoptosis, cell cycle arrest and suppression of proliferation. Proteomic data of V. b. berus venoms from different parts of Russia and Slovakian Republic have been compared with analogous data for Vipera nikolskii venom. Proteomic studies demonstrated quantitative differences in the composition of V. b. berus venom from different geographical regions. Differences in the venom composition of V. berus were mainly driven by the age, sex, habitat and diet of the snakes. The venom variability of V. berus results in a loss of antivenom efficacy against snakebites. The effectiveness of antibodies is discussed. This review presents an overview with a special focus on different toxins that have been isolated and characterized from the venoms of V. b. berus. Their main biochemical properties and toxic actions are described.

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Vipera berus berus venom composition is variable among different populations.

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Venom contains about 15 protein/peptide families.

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It disturbs blood coagulation inducing pro- or anticoagulant effects.

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Venom contains different types of blood factor X activators.

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PLA₂ and L-amino acid oxidase produce cytotoxic effects in cancer cells.

Acute Exposure to European Viper Bite in Children: Advocating for a Pediatric Approach

Viper bite is an uncommon but serious cause of envenoming in Europe, especially in children. Our study aim is to better describe and analyze the clinical course and treatment of viper bite envenoming in a pediatric population. We retrospectively reviewed 24 cases of pediatric viper bites that were admitted to the Pediatric Emergency Department and the Pediatric Intensive Care Unit of the Bambino Gesù Children Hospital in Rome between 2000 and 2020. Epidemiological characteristics of the children, localization of the bite, clinical and laboratory findings, and treatment approaches were evaluated. The median age of the patients was 4.2 years, with male predominance. Most cases of viper bite occurred in the late summer. Most patients required admission to the ward for prolonged observation. The most common presenting signs were pain, local oedema, and swelling. Patients with a high severity score also had a significantly higher white blood cell count and an increase of INR, LDH, and CRP levels. No fatality was reported. Viper bite envenomation is a rare pediatric medical emergency in Italy but may sometimes be severe. A new pediatric severity score may be implemented in the screening of children with viper bites to favor a selective and prompt administration of antivenom.