Search Results (41)

Snakebite is a significant global public health challenge, and the limited application of antivenom has driven the exploration of novel therapies. Combination therapy using small-molecule drugs targeting phospholipases A₂ (PLA2) and metalloproteinases (SVMP) in venom shows great potential. Although Rhamnetin and RXP03 exhibit notable anti-phospholipase and anti-metalloproteinase activities, respectively, their antiophidic potential remains poorly explored. This study aims to evaluate the inhibitory effects of Rhamnetin and RXP03 on snake venom toxicity. Methodologically, we conducted in vitro enzymatic assays to quantify PLA₂/SVMP inhibition, murine models of envenomation (subcutaneous/intramuscular venom injection) to assess local tissue damage and systemic toxicity, and histopathological/biochemical analyses. In vitro experiments demonstrated that Rhamnetin effectively inhibited PLA₂ activity while RXP03 showed potent suppression of SVMP activity, with their combination significantly reducing venom-induced hemorrhagic activity. In murine models, the combined therapy markedly alleviated venom-triggered muscle toxicity and ameliorated oxidative stress. Furthermore, the combination enhanced motor performance and survival rate in mice, improved serum biochemical parameters, corrected coagulation disorders, and attenuated pathological damage in liver, kidney, heart, and lung tissues. This research demonstrates that dual-targeted therapy against metalloproteinases and phospholipases in snake venom can effectively prevent a series of injuries caused by snake venom. Collectively, the combined application of Rhamnetin and RXP03 exhibits significant inhibitory effects on a variety of venom-induced toxicities, providing pharmacological evidence for the development of antivenom therapies. However, the efficacy validation in this study was limited to murine models, and there is a discrepancy with clinical needs for delayed treatment in real-world envenomation scenarios. Despite these limitations, the findings provide robust preclinical evidence supporting the Rhamnetin–RXP03 combination therapy as a cost-effective, broad-spectrum antivenom strategy. Future studies are required to optimize dosing regimens and evaluate clinical translatability. Full article

Background: The parenteral administration of antivenoms is the mainstay in snakebite envenoming therapy. The standardized protocol does not exist, but it is agreed that the intravenous (i.v.) route is more effective than the others, especially the intramuscular (i.m.) route, based on the monitoring of venom/antivenom pharmacokinetics in the systemic circulation. Recent evidence suggests that the lymphatic system may be crucial in abolishing venom action. Methods: A preclinical study was performed to determine the optimal administration route with emphasis on venom/antivenom interplay in both the blood and lymph of experimentally envenomed sheep. Timed level measurements were used to compare the antivenom effect on the decrement of venom quantities in both relevant body compartments. Hematological and coagulation parameters, as well as proportions of developed anti-antivenom IgGs, were evaluated. Results: The i.m. antivenom resulted in faster and greater lymphatic absorption and complete neutralization of the venom, whereas the i.v. antivenom only slowed its absorption. The total amount of venom reaching the lymph (AUC_0-t) was two times lower after i.m. administration. In the systemic circulation, i.m. antivenom had a lower peak concentration (c_max) and a longer time to reach it (t_max). However, the total venom exposure was three times lower than with i.v. antivenom. Irrespective of the treatment approach, both groups showed improvement in blood disorders with no significant difference in humoral response against equine F(ab’)₂ fragments. Conclusions: I.m. administration proved to be a viable option for the snakebite management. Full article

Extracellular vesicles (EVs) are nanoparticle-sized vesicles secreted by nearly all cell types under normal physiological conditions. In toxicological research, EVs have emerged as a crucial link between public health and multi-omics approaches, offering insights into cellular responses to disease-causing injury agents such as environmental and biological toxins, contaminants, and drugs. Notably, EVs present a unique opportunity to deepen our understanding of the pathophysiology of envenomation by natural toxins. Recent advancements in isolating and purifying EV cargo, mass spectrometry techniques, and bioinformatics have positioned EVs as potential biomarkers that could elucidate biological signaling pathways and provide valuable information on the relationship between venomous toxins, their mechanisms of action, and the effectiveness of antivenoms. Additionally, EVs hold promise as proxies for various aspects of envenomation, including the toxin dosage, biological characterization, injury progression, and prognosis during therapeutic interventions. These aspects can be explored through multi-omics technology applied to EV contents from the plasma, saliva, or urine samples of envenomated individuals, offering a comprehensive integrative approach to understanding and managing envenomation cases. Full article

Snakebite envenoming is a significant health threat, particularly in tropical regions, causing substantial morbidity and mortality. Traditional treatments, including antivenom therapy, have limitations and associated risks. This research aims to discover novel phytochemical antidotes for snakebites, specifically targeting the western diamondback rattlesnake (Crotalus atrox) venom metalloproteinase Atrolysin. Utilizing pharmacoinformatic techniques such as molecular docking, high-throughput ligand screening, pharmacophore mapping, pharmacokinetic profiling, and molecular dynamics (MD) simulations, we analyzed phytochemicals from the Indian Medicinal Plants, Phytochemistry And Therapeutics (IMPPAT) database alongside well-known nine metalloproteinase inhibitors from the PubChem database. From an initial set of 17,967 compounds, 4708 unique compounds were identified for further study. These compounds were evaluated based on drug likeness, molecular descriptors, ADME properties, and toxicity profiles. Binding site predictions and molecular docking identified key interacting residues and binding energies, highlighting several promising compounds. Density functional theory (DFT) analysis provided insights into these compounds’ electronic properties and stability. MD simulations assessed the dynamic stability of protein-ligand complexes using parameters such as RMSD, RMSF, the radius of gyration, and hydrogen bond interactions. This study identified top candidates, including CID5291, IMPHY001495, IMPHY014737, IMPHY008983, IMPHY008176, and IMPHY003833, based on their favorable binding energies, interaction forces, and structural stability. These findings suggest that the selected phytochemicals have the potential to serve as effective alternatives to traditional antivenom treatments, offering a promising avenue for further research and development in snakebite management. Full article

The aim of this study was to describe the frequency, clinical signs, management, and outcomes of snakebite patients admitted to the envenomation treatment center of the Institut de Recherche en Biologie Appliquée de Guinée (IRBAG). This was a retrospective review combining aggregated annual statistics (2011–2015) and routine data (from January to October 2021) from the IRBAG treatment center. There were 1345 (57.2%) snakebite victims out of a total of 2352 consultations at the center during the study period. Males (67.7%), persons aged ≥45 years (29%) and ≤14 years (27.7%), farmers/housewives (44.5%), workers (23.9%), and those residing in the Kindia Prefecture (53.5%) were the most commonly affected. The majority of victims (84.5%) were admitted three hours after snakebite, with bites mainly occurring in rural areas (86.5%) and during the rainy season (83.2%). Pain (100%), edema (76.8%), and bleeding (65.2%) were the most common clinical presentations. Almost all victims received antivenom serum (98%), antibiotics (87.7%), and analgesics or anti-inflammatory drugs (88.4%). Six out of the one hundred and fifty-five patients died. Snakebites are a frequent public health problem in rural Guinea. The majority of victims seek medical attention too late. There is an urgent need to include snakebite in the country’s list of priority NTDs in order to promote access to antivenom serum. Full article

Australian elapid snake venoms are uniquely procoagulant, utilizing blood clotting enzyme Factor Xa (FXa) as a toxin, which evolved as a basal trait in this clade. The subsequent recruitment of Factor Va (FVa) as a toxin occurred in the last common ancestor of taipans (Oxyuranus species) and brown snakes (Pseudonaja species). Factor II (prothrombin) activation has been stated as the primary mechanism for the lethal coagulopathy, but this hypothesis has never been tested. The additional activation of Factor VII (FVII) by Oxyuranus/Pseudonaja venoms has historically been considered as a minor, unimportant novelty. This study aimed to investigate the significance of toxic FVII activation relative to prothrombin activation by testing a wide taxonomical range of Australian elapid species with procoagulant venoms. The activation of FVII or prothrombin, with and without the Factor Va as a cofactor, was assessed, along with the structural changes involved in these processes. All procoagulant species could activate FVII, establishing this as a basal trait. In contrast, only some lineages could activate prothrombin, indicating that this is a derived trait. For species able to activate both zymogens, Factor VII was consistently more strongly activated than prothrombin. FVa was revealed as an essential cofactor for FVII activation, a mechanism previously undocumented. Species lacking FVa in their venom utilized endogenous plasma FVa to exert this activity. The ability of the human FXa:FVa complex to activate FVII was also revealed as a new feedback loop in the endogenous clotting cascade. Toxin sequence analyses identified structural changes essential for the derived trait of prothrombin activation. This study presents a paradigm shift in understanding how elapid venoms activate coagulation factors, highlighting the critical role of FVII activation in the pathophysiological effects upon the coagulation cascade produced by Australian elapid snake venoms. It also documented the novel use of Factor Va as a cofactor for FVII activation for both venom and endogenous forms of FXa. These findings are crucial for developing better antivenoms and treatments for snakebite victims and have broader implications for drug design and the treatment of coagulation disorders. The research also advances the evolutionary biology knowledge of snake venoms. Full article

The therapeutic properties of turmeric essential oil have been extensively documented in both preclinical and clinical studies. Research indicates that its primary active compounds are promising candidates for addressing a wide range of pathologies, exhibiting anticancer, anti-inflammation, antioxidant, cardiovascular, hypoglycemic, dermatological, hepatoprotective, neurological, antiparasitic, antiviral, insecticidal, antifungal, and antivenom activities. While numerous compounds possess similar potential applications, the isolated active constituents of turmeric essential oil stand out due to their unique pharmacological profiles and absence of toxicity. This literature review meticulously compiles and analyzes the bioactivities of these constituents, emphasizing their molecular mechanisms of action, reported pharmacological effects, and potential therapeutic applications. The aim of this review is to provide a comprehensive synthesis of currently available clinical and preclinical findings related to individual turmeric essential oil compounds, while also identifying critical knowledge gaps. By summarizing these findings, this work encourages further research into the isolated compounds from turmeric oil as viable drug candidates, ultimately contributing to the development of innovative therapeutic strategies. Full article

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

Indian Red Scorpion (Mesobuthus tamulus) stings are a neglected public health problem in tropical and sub-tropical countries, including India. The drawbacks of conventional therapies using commercial anti-scorpion antivenom (ASA) and α1-adrenoreceptor antagonists (AAA) have prompted us to search for an adequate formulation to improve treatment against M. tamulus stings. Novel therapeutic drug formulations (TDF) of low doses of commercial ASA, AAA, and ascorbic acid have remarkably improved in neutralising the in vivo toxic effects of M. tamulus venom (MTV) tested in Caenorhabditis elegans and Wistar strain albino rats in vivo models. The neutralisation of MTV-induced production of free radicals, alteration of the mitochondrial transmembrane potential, and upregulated expression of genes involved in apoptosis, detoxification, and stress response in C. elegans by TDF surpassed the same effect shown by individual components of the TDF. Further, TDF efficiently neutralized the MTV-induced increase in blood glucose level within 30 to 60 min post-treatment, organ tissue damage, necrosis, and pulmonary oedema in Wistar rats, indicating its clinical application for effecting treating M. tamulus envenomation. This study demonstrates for the first time that C. elegans can be a model organism for screening the neutralization potency of the drug molecules against a neurotoxic scorpion venom. Full article

A pioneering study regarding the isolation, biochemical evaluation, functional assays and first PEGylation report of a novel vascular endothelial growth factor from Crotalus durissus terrificus venom (CdtVEGF and PEG-CdtVEGF). CdtVEGF was isolated from crude venom using two different chromatographic steps, representing 2% of soluble venom proteins. Its primary sequence was determined using mass spectrometry analysis, and the molecule demonstrated no affinity to heparin. The Brazilian crotalid antivenom recognized CdtVEGF. Both native and PEGylated CdtVEGF were able to induce new vessel formation and migration, and to increase the metabolic activity of human umbilical endothelial vascular cells (HUVEC), resulting in better wound closure (~50% within 12 h) using the native form. CdtVEGF induced leukocyte recruitment to the peritoneal cavity in mice, with a predominance of neutrophil influx followed by lymphocytes, demonstrating the ability to activate the immune system. The molecule also induced a dose-dependent increase in vascular permeability, and PEG-CdtVEGF showed less in vivo inflammatory activity than CdtVEGF. By unraveling the intricate properties of minor components of snake venom like svVEGF, this study illuminates the indispensable significance of exploring these molecular tools to unveil physiological and pathological processes, elucidates the mechanisms of snakebite envenomings, and could possibly be used to design a therapeutic drug. Full article

Humans have faced poisonous animals since the most ancient times. It is recognized that certain animals, like specific plants, produce toxic substances that can be lethal, but that can also have therapeutic or psychoactive effects. The use of the term “venom”, which initially designated a poison, remedy, or magic drug, is now confined to animal poisons delivered by biting. Following Louis Pasteur’s work on pathogenic microorganisms, it was hypothesized that venoms could be related to bacterial toxins and that the process of pathogenicity attenuation could be applied to venoms for the prevention and treatment of envenomation. Cesaire Phisalix and Gabriel Bertrand from the National Museum of Natural History as well as Albert Calmette from the Institut Pasteur in Paris were pioneers in the development of antivenomous serotherapy. Gaston Ramon refined the process of venom attenuation for the immunization of horses using a formalin treatment method that was successful for diphtheria and tetanus toxins. This paved the way for the production of antivenomous sera at the Institut Pasteur, as well as for research on venom constituents and the characterization of their biological activities. The specific activities of certain venom components, such as those involved in blood coagulation or the regulation of chloride ion channels, raises the possibility of developing novel therapeutic drugs that could serve as anticoagulants or as a treatment for cystic fibrosis, for example. Scientists of the Institut Pasteur of Paris have significantly contributed to the study of snake venoms, a topic that is reported in this review. Full article

Envenomations induced by animal bites and stings constitute a significant public health burden. Even though a standardized protocol does not exist, parenterally administered polyclonal antivenoms remain the mainstay in snakebite therapy. There is a prevailing opinion that their application by the i.m. route has poor efficacy and that i.v. administration should preferentially be chosen in order to achieve better accomplishment of the antivenom therapeutic activity. Recently, it has been demonstrated that neutralization not only in the systemic circulation but also in the lymphatic system might be of great importance for the clinical outcome since it represents another relevant body compartment through which the absorption of the venom components occurs. In this review, the present-day and summarized knowledge of the laboratory and clinical findings on the i.v. and i.m. routes of antivenom administration is provided, with a special emphasis on the contribution of the lymphatic system to the process of venom elimination. Until now, antivenom-mediated neutralization has not yet been discussed in the context of the synergistic action of both blood and lymph. A current viewpoint might help to improve the comprehension of the venom/antivenom pharmacokinetics and the optimal approach for drug application. There is a great need for additional dependable, practical, well-designed studies, as well as more practice-related experience reports. As a result, opportunities for resolving long-standing disputes over choosing one therapeutic principle over another might be created, improving the safety and effectiveness of snakebite management. Full article

Carissa spinarum L. (Apocynaceae), commonly known as Garna or Jungli Karonda, has a rich history of use in indigenous traditional medicinal systems owing to its tremendous medicinal and nutritional benefits. The present review aims to discuss the traditional uses, ethnopharmacology, bioactive composition, toxicity analysis, and biotechnological applications of Carissa spinarum L. (CS) to identify the gap between current applications and research conducted on this plant. We collected the literature published before December 2022 on the phytochemical composition, pharmacological properties, and biotechnological applications of CS. Literature in English from scientific databases such as Google Scholar, PubMed, ScienceDirect, Springer, and Wiley, along with books on CS, was analyzed and summarized to prepare this review. The plant taxonomy was verified using the “World Flora Online” database. The in vitro and in vivo pharmacological studies on CS revealed its anthelmintic, anticonvulsant, anti-arthritic, anti-inflammatory, antimicrobial, antioxidant, antidiabetic, hepatoprotective, vasorelaxant, antihypertensive, antitumor, wound-healing, anti-venom, and antipyretic effects. Toxicological studies on CS also indicated the absence of any adverse effects even at high doses after oral administration. Although CS showed remarkable therapeutic activities against several diseases—such as diabetes, cancer, inflammation, and hepatitis B virus—there are several drawbacks in previous reports, including the lack of information on the drug dose, standards, controls, and mechanism of action of the extract or the phytocompounds responsible for its activity. Extensive research with proper in vivo or in vitro model systems is required to validate its reported activities. Full article

Respiratory and airway-protective muscle weakness caused by the blockade of neuromuscular transmission is a major cause of early mortality from snakebite envenoming (SBE). Once weakness is manifest, antivenom appears to be of limited effectiveness in improving neuromuscular function. Herein, we review the topic of venom-induced neuromuscular blockade and consider the utility of adopting clinical management methods originally developed for the safe use of neuromuscular blocking agents by anesthesiologists in operating rooms and critical care units. Failure to quantify neuromuscular weakness in SBE is predicted to cause the same significant morbidity that is associated with failure to do so in the context of using a clinical neuromuscular block in surgery and critical care. The quantitative monitoring of a neuromuscular block, and an understanding of its neurophysiological characteristics, enables an objective measurement of weakness that may otherwise be overlooked by traditional clinical examination at the bedside. This is important for the initial assessment and the monitoring of recovery from neurotoxic envenoming. Adopting these methods will also be critical to the conduct of future clinical trials of toxin-inhibiting drugs and antivenoms being tested for the reversal of venom-induced neuromuscular block. Full article

The availability of effective, reliably accessible, and affordable treatments for snakebite envenoming is a critical and long unmet medical need. Recently, small, synthetic toxin-specific inhibitors with oral bioavailability used in conjunction with antivenom have been identified as having the potential to greatly improve outcomes after snakebite. Varespladib, a small, synthetic molecule that broadly and potently inhibits secreted phospholipase A2 (sPLA2s) venom toxins has renewed interest in this class of inhibitors due to its potential utility in the treatment of snakebite envenoming. The development of varespladib and its oral dosage form, varespladib-methyl, has been accelerated by previous clinical development campaigns to treat non-envenoming conditions related to ulcerative colitis, rheumatoid arthritis, asthma, sepsis, and acute coronary syndrome. To date, twenty-nine clinical studies evaluating the safety, pharmacokinetics (PK), and efficacy of varespladib for non-snakebite envenoming conditions have been completed in more than 4600 human subjects, and the drugs were generally well-tolerated and considered safe for use in humans. Since 2016, more than 30 publications describing the structure, function, and efficacy of varespladib have directly addressed its potential for the treatment of snakebite. This review summarizes preclinical findings and outlines the scientific support, the potential limitations, and the next steps in the development of varespladib’s use as a snakebite treatment, which is now in Phase 2 human clinical trials in the United States and India. Full article