Analysis of the Composition of Deinagkistrodon acutus Snake Venom Based on Proteomics, and Its Antithrombotic Activity and Toxicity Studies

Forensic identification of a fatality in a child due to a bite from Deinagkistrodon acutus: A case report

The five-paced viper (Deinagkistrodon acutus) is a prevalent venomous snake in China. Its venom comprises metalloproteinases, phospholipase A2, C-type lectin-like proteins, and serine proteases, which can induce acute reactions such as tissue inflammation, edema, necrosis, hemorrhage, coagulopathy, and even multiple organ failure. This report details a case involving a child in a rural area of China who was accidentally bitten by Deinagkistrodon acutus while playing outdoors and subsequently died despite treatment. The autopsy findings and histopathological results may assist in the clinical management and forensic practice related to Deinagkistrodon acutus envenomation in the future.

Cerebrovascular events induced by venomous snake bites: A systematic review

Snake bites represent a critical public health issue, affecting approximately 2.7 million people globally each year. Around 20 % of snake species are venomous, and their venom contains a complex array of toxins that can cause multi-organ damage, particularly affecting the nervous system, leading to both ischemic and hemorrhagic cerebrovascular events. This systematic review aims to compile and analyze data on cerebrovascular events associated with venomous snakebites. A comprehensive literature search was conducted using Scopus, PubMed, SciELO, and LILACS databases, with search terms including ("snake bite" OR "viper bite") AND ("stroke" OR "hemorrhagic stroke" OR "ischemic stroke"). Studies in English, Spanish, French and Portuguese were reviewed, yielding 52 eligible articles reporting 73 cases of stroke following snakebites. Most cases were attributed to snakes from the Viperidae family, with 67.12 % of cases occurring in males. Ischemic strokes were the most frequent, comprising 73.97 % of reported cases. The most affected systems were the nervous, cardiovascular, and respiratory systems. Snakes from the Bothrops genera and Daboia russelii specie caused the widest range of symptoms, including altered consciousness, ptosis, hypertension, drowsiness, aphasia, and tachycardia. Stroke is a severe complication of snakebite envenomation. Regarding treatment, the articles included emphasize the use of antivenom serum; however, they do not go into detail about the specific management of cutaneous stroke due to a snakebite, whether ischemic or hemorrhagic It is crucial to develop standardized protocols for the management of snakebite-induced strokes and to conduct further research to identify the snake species whose venom poses the highest risk for cerebrovascular complications.

A genus-wide study on venom proteome variation and phospholipase A2 inhibition in Asian lance-headed pit vipers (genus: Trimeresurus)

High molecular weight proteins are present abundantly in viperid venoms. The amino acid sequence can be highly variable, contributing to the structure and function diversity of snake venom protein. However, this variability remains poorly understood in many species. The study investigated the venom protein variability in a distinct clade of Asian pit vipers (Trimeresurus species complex) through comparative proteomics, applying gel electrophoresis (SDS-PAGE), liquid chromatography-tandem mass spectrometry (LCMS/MS), and bioinformatic approaches. The proteomes revealed a number of conserved protein families, within each are variably expressed protein paralogs that are unrelated to the snake phylogeny and geographic origin. The expression levels of two major enzymes, i.e., snake venom serine proteinase and metalloproteinase, correlate weakly with procoagulant and hemorrhagic activities, implying co-expression of other functionally versatile toxins in the venom. The phospholipase A2 (PLA2) abundance correlates strongly with its enzymatic activity, and a unique phenotype was discovered in two species expressing extremely little PLA2. The commercial mono-specific antivenom effectively neutralized the venoms' procoagulant and hemorrhagic effects but failed to inhibit the PLA2 activities. Instead, the PLA2 activities of all venoms were effectively inhibited by the small molecule inhibitor varespladib, suggesting its potential to be repurposed as a highly potent adjuvant therapeutic in snakebite envenoming.

Current Technologies in Snake Venom Analysis and Applications

This comprehensive review explores the cutting-edge advancements in snake venom research, focusing on the integration of proteomics, genomics, transcriptomics, and bioinformatics. Highlighting the transformative impact of these technologies, the review delves into the genetic and ecological factors driving venom evolution, the complex molecular composition of venoms, and the regulatory mechanisms underlying toxin production. The application of synthetic biology and multi-omics approaches, collectively known as venomics, has revolutionized the field, providing deeper insights into venom function and its therapeutic potential. Despite significant progress, challenges such as the functional characterization of toxins and the development of cost-effective antivenoms remain. This review also discusses the future directions of venom research, emphasizing the need for interdisciplinary collaborations and new technologies (mRNAs, cryo-electron microscopy for structural determinations of toxin complexes, synthetic biology, and other technologies) to fully harness the biomedical potential of venoms and toxins from snakes and other animals.

Proteogenomics-guided functional venomics resolves the toxin arsenal and activity of Deinagkistrodon acutus venom

Snakebite primarily impacts rural communities of Africa, Asia, and Latin America. The sharp-nosed viper (Deinagkistrodon acutus) is among the snakes of highest medical importance in Asia. Despite various studies on its venom using modern venomics techniques, a comprehensive understanding of composition and function of this species' venom remains lacking. We combined proteogenomics with extensive bioactivity profiling to present the first genome-level catalogue of D. acutus venom proteins and their exochemistry. Our analysis identified an unusually simple venom containing 45 components from 20 distinct protein families. Relative toxin abundances indicate that C-type lectin and C-type lectin-related protein (CTL), snake venom metalloproteinase (svMP), snake venom serine protease (svSP), and phospholipase A2 (PLA2) constitute 90 % of the venom. Bioassays targeting key aspects of viperid envenomation showed considerable concentration-dependent cytotoxicity, particularly in kidney and lung cells, and potent protease and PLA2 activity. Factor Xa and thrombin activities were minor, and no plasmin activity was observed. Effects on haemolysis, intracellular calcium (Ca2+) release, and nitric oxide (NO) synthesis were negligible. Our analysis provides the first holistic genome-based overview of the toxin arsenal of D. acutus, predicting the molecular and functional basis of its life-threatening effects, and opens novel avenues for treating envenomation by this highly dangerous snake.

Structural, Biochemical Characterization and Molecular Mechanism of Cerastokunin: A New Kunitz-Type Peptide with Potential Inhibition of Thrombin, Factor Xa and Platelets

The current investigation focused on separating Cerastes cerastes venom to produce the first Kunitz-type peptide. Based on its anti-trypsin effect, Cerastokunin, a 7.75 kDa peptide, was purified until homogenity by three steps of chromatography. Cerastokunin was found to include 67 amino acid residues that were obtained by de novo sequencing using LC-MALDI-MSMS. Upon alignment with Kunitz-type peptides, there was a high degree of similarity. Cerastokunin's 3D structure had 12% α-helices and 21% β-strands with pI 8.48. Cerastokunin showed a potent anticoagulant effect by inhibiting the protease activity of thrombin and trypsin as well as blocking the intrinsic and extrinsic coagulation pathways. In both PT and aPPT, Cerastokunin increased the blood clotting time in a dose-dependent way. Using Lys48 and Gln192 for direct binding, Cerastokunin inhibited thrombin, Factor Xa and trypsin as shown by molecular docking. Cerastokunin exhibited a dose-response blockade of PARs-dependent pathway platelet once stimulated by thrombin. An increased concentration of Cerastokunin resulted in a larger decrease of tail thrombus in the mice-carrageenan model in an in vivo investigation when compared to the effects of antithrombotic medications. At all Cerastokunin doses up to 6 mg/kg, no in vivo toxicity was seen in challenged mice over the trial's duration.

Metabolomics and network pharmacology reveal the mechanism of antithrombotic effect of Asperosaponin VI

Dipsaci Radix may possess antithrombotic properties, and one of its primary active ingredients is Asperosaponin VI. However, the antithrombotic effects and pharmacological mechanisms of Asperosaponin VI remain unclear. An in vivo experimental study has demonstrated the antithrombotic activity of Asperosaponin VI. Asperosaponin VI also exhibits anticoagulant properties. Asperosaponin VI significantly hindered collagen adrenergic-induced acute pulmonary thrombosis in mice and enhanced their survival rate. This hinders the formation of acute pulmonary embolisms induced by adenosine diphosphate (ADP) and decreases recovery time. A comprehensive strategy that combines metabolomics, network pharmacology, molecular docking, and experimental validation has the potential to reveal the antithrombotic mechanisms of Asperosaponin VI. Metabolomic evidence suggests that Asperosaponin VI may influence platelet aggregation and the production of anti-inflammatory metabolites through the regulation of pathways such as phenylalanine and arachidonic acid metabolism, thereby inhibiting thrombosis. Network pharmacology identified the pharmacological targets of Asperosaponin VI and indicated that it treats thrombi by partially regulating the signaling pathways related to inflammation and platelet aggregation. Asperosaponin VI showed strong binding affinity for F2, PTPRC, JUN, STAT3, SRC, AKT1. The antiplatelet aggregation activity of Asperosaponin VI was validated based on the metabolomic and network pharmacology results. Asperosaponin VI inhibits platelet aggregation induced by ADP, AA, and collagen. Therefore, Asperosaponin VI exerts antithrombotic effects through antiplatelet aggregation. Therefore, Asperosaponin VI is a promising antithrombotic agent.

Comparative analysis of Deinagkistrodon acutus venom from Taiwan and China utilizing chromatographic, electrophoretic, and bioinformatic approaches, along with ELISA employing a monospecific antivenom

Deinagkistrodon acutus is a medically important pitviper inhabiting mainly South China and Taiwan. The hemorrhagic effects of its envenoming are compatible to its venom, which is abundant in metalloproteases (svMPs) and C-type lectin-like proteins. In this study, we investigated geographic variations in the venom of D. acutus collected from Taiwan and four Mainland Chinese provinces: Fujian, Jiangxi, Anhui, and Hunan. The variations were assessed through high-performance liquid chromatography, non-metric multidimensional scaling analysis, gel electrophoresis, and enzyme-linked immunosorbent assay (ELISA) with a monospecific antivenom (DaMAV) generated against the Taiwanese D. acutus venom, and discussed based on venom-protein sequences in databases and literature related to D. acutus venom. Additionally, the cross-reactivity of DaMAV against Crotalus horridus and Calloselasma rhodostoma venoms was investigated. We noted differential abundances of D. acutus venom metalloproteases, C-type lectin-like proteins, and phospholipase A2, along with point mutations and selective expression of serine protease isoforms. The ELISA results revealed that the venom from Taiwan was more reactive toward Taiwanese DaMAV than the four Mainland Chinese venoms, consistent with chromatographic profile differences, whereas C. horridus venom presented moderate cross-reactivity with DaMAV. The observed immunoreactivities of these venom with DaMAV can be attributed to the high prevalence of their PIII-svMPs, which are the dominant antigens, and the conservation of PIII-svMP epitopes.

Proteomics and Metabolomics in Biomedicine

The technological advances of recent years have significantly enhanced medical discoveries [...].

Genome assembly and annotation of the Sharp-nosed Pit Viper Deinagkistrodon acutus based on next-generation sequencing data

The study of the currently known >3,000 species of snakes can provide valuable insights into the evolution of their genomes. Deinagkistrodon acutus, also known as Sharp-nosed Pit Viper, one hundred-pacer viper or five-pacer viper, is a venomous snake with significant economic, medicinal and scientific importance. Widely distributed in southeastern China and South-East Asia, D. acutus has been primarily studied for its venom. Here, we employed next-generation sequencing to assemble and annotate a highly continuous genome of D. acutus. The genome size is 1.46 Gb; its scaffold N50 length is 6.21 Mb, the repeat content is 42.81%, and 24,402 functional genes were annotated. This study helps to further understand and utilize D. acutus and its venom at the genetic level.

A case report of Ovophis monitcola (Mountain pit-viper) envenoming in northeastern India resulting in prolonged coagulopathy

India is home to a diverse spectrum of medically-significant snakes accounting for the world's largest burden of envenoming, morbidity and mortality. Indian polyspecific antivenom is derived from the venom of four snake species (Daboia russelii, Echis carinatus, Naja naja and Bungarus caeruleus), considered to be responsible for the majority of snakebite morbidity and mortality. The treatment of venomous bites from other less-commonly encountered venomous snake species can be challenging. In this report, we describe the case of a 32-year-old male who presented with features of local cytotoxicity and coagulopathy following a bite from Ovophis monitcola (mountain pit-viper) in Nagaland, northeast India. Local and systemic envenoming, confirmed by bedside and laboratory based clotting assays, failed to respond to polyspecific antivenom and venom-induced consumption coagulopathy persisted for 28 days. Remote consultation with a national Poison Control Centre helped establish the responsible snake species and guide appropriate medical management.

Identification of Protein Quality Markers in Toad Venom from Bufo gargarizans

Toad venom is a traditional Chinese medicine with high medicinal value. The existing quality evaluation standards of toad venom have obvious limitations because of the lack of research on proteins. Thus, it is necessary to screen suitable quality markers and establish appropriate quality evaluation methods for toad venom proteins to guarantee their safety and efficacy in clinical applications. SDS-PAGE, HPLC, and cytotoxicity assays were used to analyze differences in protein components of toad venom from different areas. Functional proteins were screened as potential quality markers by proteomic and bioinformatic analyses. The protein components and small molecular components of toad venom were not correlated in content. Additionally, the protein component had strong cytotoxicity. Proteomics analysis showed that 13 antimicrobial proteins, four anti-inflammatory and analgesic proteins, and 20 antitumor proteins were differentially expressed extracellular proteins. A candidate list of functional proteins was coded as potential quality markers. Moreover, Lysozyme C-1, which has antimicrobial activity, and Neuropeptide B (NPB), which has anti-inflammatory and analgesic activity, were identified as potential quality markers for toad venom proteins. Quality markers can be used as the basis of quality studies of toad venom proteins and help to construct and improve safe, scientific, and comprehensive quality evaluation methods.

Immunoprofiling of Equine Plasma against Deinagkistrodon acutus in Taiwan: Key to Understanding Differential Neutralization Potency in Immunized Horses

Snakebite envenoming is a public health issue linked to high mortality and morbidity rates worldwide. Although antivenom has been the mainstay treatment for envenomed victims receiving medical care, the diverse therapeutic efficacy of the produced antivenom is a major limitation. Deinagkistrodon acutus is a venomous snake that poses significant concern of risks to human life in Taiwan, and successful production of antivenom against D. acutus envenoming remains a considerable challenge. Among groups of horses subjected to immunization schedules, few or none subsequently meet the quality required for further scale-up harvesting. The determinants underlying the variable immune responses of horses to D. acutus venom are currently unknown. In this study, we assessed the immunoprofiles of high-potency and low-potency horse plasma against D. acutus venom and explored the conspicuous differences between these two groups. Based on the results of liquid chromatography with tandem mass spectrometry (LC-MS/MS), acutolysin A was identified as the major component of venom proteins that immunoreacted differentially with the two plasma samples. Our findings indicate underlying differences in antivenoms with variable neutralization efficacies, and may provide valuable insights for improvement of antivenom production in the future.

Sharp-nosed Pit Viper (Deinagkistrodon acutus) from Taiwan and China: A comparative study on venom toxicity and neutralization by two specific antivenoms across the Strait

In East Asia, the Sharp-nosed Pit Viper (Deinagkistrodon acutus) is a medically important venomous snake in Taiwan and China, two geographical areas long separated by the Taiwan Strait. Yet, snake venom variation is little known between specimens found across the Strait. This study thus investigated the intra-species variation of D. acutus venoms from Taiwan (Da-Taiwan) and China (Da-China) in their profiles of gel electrophoresis, toxicity, immunoreactivity and neutralization effect by antivenom. Da-China venom exhibited higher procoagulant, hemorrhagic and lethal activities than Da-Taiwan venom, presumably attributed to the higher abundance of moderate-to-high molecular weight toxins (procoagulants and hemorrhagins) in the venom. The mono-specific antivenoms produced in Taiwan (DaMAV-Taiwan) and China (DaMAV-China) were immunoreactive toward both venoms, and were able to neutralize the venom toxicity to different extents. DaMAV-Taiwan was more efficacious in neutralizing the venom procoagulant and lethal effects, while DaMAV-China was more potent against hemorrhagic effect. The discrepancy in efficacy between the two antivenoms could be due to varying proportions of neutralizing antibodies in the respective products, influenced by techniques of antibody raising and purification. Further study is warranted to elucidate variation in the proteome and antigenicity of D. acutus venom between snakes from Taiwan and China.

Separation and Analytical Techniques Used in Snake Venomics: A Review Article

The deleterious consequences of snake envenomation are due to the extreme protein complexity of snake venoms. Therefore, the identification of their components is crucial for understanding the clinical manifestations of envenomation pathophysiology and for the development of effective antivenoms. In addition, snake venoms are considered as libraries of bioactive molecules that can be used to develop innovative drugs. Numerous separation and analytical techniques are combined to study snake venom composition including chromatographic techniques such as size exclusion and RP-HPLC and electrophoretic techniques. Herein, we present in detail these existing techniques and their applications in snake venom research. In the first part, we discuss the different possible technical combinations that could be used to isolate and purify SV proteins using what is known as bioassay-guided fractionation. In the second part, we describe four different proteomic strategies that could be applied for venomics studies to evaluate whole venom composition, including the mostly used technique: RP-HPLC. Eventually, we show that to date, there is no standard technique used for the separation of all snake venoms. Thus, different combinations might be developed, taking into consideration the main objective of the study, the available resources, and the properties of the target molecules to be isolated.