Search Results (260)

Scorpionism is a growing public health concern in Brazil, with the Amazon region presenting the highest mortality rates but remaining understudied, especially regarding local scorpion venoms composition. This study presents the first comprehensive biochemical characterization of venoms from three Amazonian species—Tityus metuendus (TmetuV), Tityus silvestris (TsilvV), and Brotheas amazonicus (BamazV)—using an integrated approach combining Multi-Enzymatic Limited Digestion (MELD)-based bottom-up proteomics, high-resolution LC-MS/MS, chromatography, zymography, and enzymatic assays. Tityus serrulatus venom was included as a reference. Significant biochemical differences were observed: TsilvV was rich in 20–30 kDa proteins and showed strong metalloprotease activity; BamazV exhibited high molecular weight proteins and potent phospholipase A₂ (PLA₂) activity but lacked proteolytic and fibrinogenolytic activities; TmetuV showed the highest hyaluronidase activity and abundance of α-KTx neurotoxins. Zymography revealed a conserved ~45 kDa hyaluronidase in all species. Three novel components were partially characterized: BamazPLA₂ (Group III PLA₂), Tmetu1 (37-residue α-KTx), and TsilvMP_A (a metalloprotease homologous to antarease). This is the first application of MELD-based proteomics to Amazonian scorpion venoms, revealing molecular diversity and functional divergence within Tityus and Brotheas, emphasizing the need for region-specific antivenoms. These findings provide a foundation for future pharmacological studies and the discovery of bioactive peptides with therapeutic potential. Full article

In Brazil, the annual scorpion sting cases surpass those of other neglected tropical diseases, highlighting a significant public health issue. The severity of scorpion envenomation relates to the venom’s rapid action, complex composition, species identification challenges, and limited antivenom availability. This work aimed to characterize the venom of Tityus confluens through proteomic, enzymatic, and biological analyses while also assessing its reactivity to anti-scorpion antivenom. The electrophoretic analysis revealed seven protein bands, with the most prominent bands at 30, 15, and 10 kDa. The C18-RP-HPLC analysis isolated sixteen primary fractions. The proteomic analysis identified various toxins, including potassium channel toxins, sodium channel toxins, and antimicrobial peptides, as well as other proteins such as hypotensin and metalloproteinases. Antigenic components were identified in the T. confluens venom, which displayed dose-dependent but time-independent amylolytic activity. The ATPase activity significantly increased with 1–10 μg of venom. No cytotoxic effects were observed on carcinoma or non-tumoral cell lines. The T. confluens venom features a complex protein composition rich in toxins that target ion channels and enzymes. It exhibits active enzymatic and antigenic properties, and displays low cytotoxicity. This is the first proteomic research on the composition of T. confluens venom and may provide valuable insights into understanding the clinical manifestations of scorpion stings. Full article

Venoms of the Palearctic vipers in the Macrovipera genus cause severe procoagulant clinical effects, yet the precise molecular targets remain incompletely defined. To fill this toxicological knowledge gap, we tested five Macrovipera venoms—M. lebetina cernovi, M. l. obtusa, M. l. turanica (Turkmenistan and Uzbekistan localities), and M. schweizeri—using plasma clotting assays, Factors VII, X, XI, and XII and prothrombin zymogen activation assays, and SDS-PAGE to visualise Factor V (FV) cleavage. All venoms induced extremely rapid clot formation (10.5–12.5 s) compared with the negative control (spontaneous clotting) of 334.6 ± 3.6 s) and the positive control (kaolin trigger) of 55.8 ± 1.9 s. Activation of FVII or FXI was negligible, whereas consistent FX activation and species-variable FXII activation, both moderate, were observed. Prothrombin remained inert in the absence of cofactors, but the presence of FV or FVa elicited potent thrombin generation. SDS-PAGE confirmed proteolytic conversion of the 330 kDa FV zymogen into the ~105 kDa heavy and ~80 kDa light chains of FVa by the venoms of all species. This data demonstrates that Macrovipera venoms rely on a dual enzyme strategy: (i) activation of FV to FVa by serine proteases and (ii) FVa-dependent prothrombin activation by metalloproteases. These results reveal that prothrombin activation is the dominant procoagulant pathway and overshadows the historically emphasised FX activation. This mechanism mirrors, yet is evolutionarily independent from, the FXa:FVa prothrombinase formation seen in Australian elapid venoms, highlighting convergent evolution of cofactor-hijacking strategies among snakes. The discovery of potent FVa-mediated prothrombin activation in Macrovipera challenges existing paradigms of viperid venom action, prompts re-evaluation of related genera (e.g., Daboia), and underpins the design of targeted antivenom and therapeutic interventions. Full article

Background/Objectives: Most snakebite incidents in Latin America are caused by species of the Bothrops genus. Their venom induces severe local effects, against which antivenom therapy has limited efficacy. Metabolites derived from Coffea arabica have demonstrated anti-inflammatory and anticoagulant properties, suggesting their potential as therapeutic agents to inhibit the local effects induced by B. asper venom. Methods: Three enzymatic assays were performed: inhibition of the procoagulant and amidolytic activities of snake venom serine proteinases (SVSPs); inhibition of the proteolytic activity of snake venom metalloproteinases (SVMPs); and inhibition of the catalytic activity of snake venom phospholipases A₂ (PLA_2s). Additionally, molecular docking studies were conducted to propose potential inhibitory mechanisms of the metabolites chlorogenic acid, caffeine, and caffeic acid. Results: Green and roasted coffee extracts partially inhibited the enzymatic activity of SVSPs and SVMPs. Notably, the green coffee extract, at a 1:20 ratio, effectively inhibited PLA₂ activity. Among the individual metabolites tested, partial inhibition of SVSP and PLA₂ activities was observed, whereas no significant inhibition of SVMP proteolytic activity was detected. Chlorogenic acid was the most effective metabolite, significantly prolonging plasma coagulation time and achieving up to 82% inhibition at a concentration of 62.5 μM. Molecular docking analysis revealed interactions between chlorogenic acid and key active site residues of SVSP and PLA₂ enzymes from B. asper venom. Conclusions: The roasted coffee extract demonstrated the highest inhibitory effect on venom toxins, potentially due to the formation of bioactive compounds during the Maillard reaction. Molecular modeling suggests that the tested inhibitors may bind to and occupy the substrate-binding clefts of the target enzymes. These findings support further in vivo research to explore the use of plant-derived polyphenols as adjuvant therapies in the treatment of snakebite envenoming. Full article

Plant latex is a rich source of proteolytic enzymes with potential biomedical applications, particularly in hemostasis. Among them, thrombin-like enzymes (TLEs) have garnered interest in their ability to mimic thrombin by catalyzing the conversion of fibrinogen to fibrin, facilitating clot formation. While TLEs from snake venoms have been well-characterized and applied clinically, their plant-derived counterparts remain underexplored. This review critically examines the structural and functional characteristics of TLEs from plant latex, comparing them to animal-derived TLEs and evaluating their role in both procoagulant and fibrinolytic processes. Emphasis is placed on dual fibrinogenolytic and fibrinolytic activities exhibited by latex proteases, which often vary with concentration, incubation time, and protease type. In vitro coagulation assays and electrophoretic analyses are discussed as critical tools for characterizing their multifunctionality. By addressing the knowledge gaps and proposing future directions, this paper positions plant latex proteases as promising candidates for development in localized hemostatic and thrombolytic therapies. Full article

This study used all-atom molecular dynamics simulations to investigate the structural dynamics of Ves a 1, a phospholipase from Vespa affinis venom, and its interactions within a lipid membrane environment, both alone and in the presence of the inhibitor voxilaprevir. Simulations conducted over 1 $\mathsf{\mu }$s for triplicate runs demonstrated system stability and convergence of structural properties. Our findings reveal that Ves a 1 engages in dynamic interactions with the lipid bilayer, involving key regions such as its lids, catalytic triad, and auxiliary site. The presence of voxilaprevir was observed to subtly alter these membrane interaction patterns and influence the enzyme’s catalytic area, reflecting the inhibitor’s impact within its physiological context. These results emphasize the crucial role of the lipid bilayer in shaping enzyme function and highlight voxilaprevir as a promising candidate for further inhibitor development, offering vital insights for rational drug design targeting membrane-associated proteins. Full article

Animal venoms are complex biochemical secretions rich in highly potent and selective bioactive molecules, including peptides, enzymes, and small organic compounds. Once associated primarily with toxicity, these venoms are now recognized as a promising source of therapeutic agents for a wide range of medical conditions. This review provides a comprehensive analysis of the pharmacological potential of venom-derived compounds, highlighting their mechanisms of action, such as ion channel modulation, receptor targeting, and enzyme inhibition. Successful venom-derived drugs like captopril and ziconotide exemplify the translational potential of this biological arsenal. We discuss therapeutic applications in cardiovascular diseases, chronic pain, cancer, thrombosis, and infectious diseases, as well as emerging peptide candidates in clinical development. Technological advancements in omics, structural biology, and synthetic peptide engineering have significantly enhanced the discovery and optimization of venom-based therapeutics. Despite challenges related to stability, immunogenicity, and ecological sustainability, the integration of AI-driven drug discovery and personalized medicine is expected to accelerate progress in this field. By synthesizing current findings and future directions, this review underscores the transformative potential of animal venoms in modern pharmacotherapy and drug development. We also discuss current therapeutic limitations and how venom-derived compounds may address unmet needs in specific disorders. Full article

Background: Ophidism is a globally neglected health problem. In Argentina, Crotalus durissus terrificus (C.d.t., South American rattlesnake) is one of the species of greatest medical importance since its venom contains mainly crotoxin (CTX), a potent enzyme–toxin with PLA₂ activity, which is responsible for its high lethality. Objective: In this work, we aimed to generate nanovenoms (NVs), complexes formed by CTX adsorbed onto 150 nm silica nanoparticles (SiNPs), and to study their physicochemical, biological, and immunomodulatory activities for potential use as adjuvants (ADJs) in antivenom (AV) production. Methods: CTX was isolated and corroborated by SDS-PAGE. Then, CTX was adsorbed on the synthetized Stöber SiNPs’ surfaces, forming a monolayer and retaining its biological activity (as observed by the MTT cell proliferation assay using the THP-1 cell line). Results: Immunomodulatory activity revealed a high pro-inflammatory (IL-1β) response induced by SiNPs followed by NVs. In the case of the anti-inflammatory response, NVs presented significant differences for TGF-β only after cell activation with LPS. No significant differences were observed in IL-10 levels. Conclusions: Thus, these results suggest that NVs together with SiNPs could increase immunogenicity and enhance immune response, turning them into potential tools for the generation of new antivenoms. Full article

The venom of Nemopilema nomurai jellyfish represents a promising source of bioactive compounds with potential pharmacological applications. In our previous work, we identified two novel angiotensin-converting enzyme (ACE)-inhibitory peptides—IVGRPLANG (896.48 Da) and IGDEPRHQYL (1227.65 Da)—isolated from N. nomurai venom hydrolysates via papain digestion. In this study, we conducted a detailed biochemical and computational characterization of these peptides. The IC₅₀ values were determined to be 23.81 µM for IVGRPLANG and 5.68 µM for IGDEPRHQYL. Kinetic analysis using Lineweaver–Burk plots revealed that both peptides act as competitive ACE inhibitors, with calculated inhibition constants (K_i) of 51.38 µM and 5.45 µM, respectively. To assess the structural stability of the ACE–peptide complexes, molecular dynamics simulations were performed. Root mean square deviation (RMSD) and root mean square fluctuation (RMSF) analyses provided insights into complex stability, while interaction fraction analysis elucidated key bond types and residue–ligand contacts involved in binding. Furthermore, a network pharmacology approach was employed to predict therapeutic targets within the renin–angiotensin–aldosterone system (RAAS). Eleven target proteins were identified: IVGRPLANG was associated with REN, ACE, CTSB, CTSS, and AGTR2; IGDEPRHQYL was linked to REN, AGT, AGTR1, AGTR2, KNG1, and BDKR2. Molecular docking analyses using HADDOCK software (version 2.4) were conducted for all targets to evaluate binding affinities, providing further insight into the peptides’ therapeutic potential. Full article

Phospholipase A₂ (PLA₂) is a prevalent molecule in the honeybee venom. Its importance is reflected by the number of scientists focused on studying it from various points of view. This review summarises a significant amount of data concerning this fascinating substance. Firstly, the origin and occurrence of PLA₂, with similarities and differences among species or populations of bees are highlighted. Next, its synthesis, post-translational processing and structural features are described, followed by the PLA₂ availability. In a larger section, the multiple effects of honeybee venom PLA₂ are detailed, starting with the main ability as an enzyme to interact with biological membranes and to hydrolyse the sn-2 ester bond in 1,2-diacyl-sn-3-phosphoglycerides; the docking process, the substrate binding and the catalytic steps are analysed too. Then, the pro-/anti-inflammatory effect and allergenic property, the anticoagulant effect and the involvement of PLA₂ in apoptosis are revised. Selected antiviral, antibiotic and antitumoral effects of PLA₂, as well as its use in immunotherapy are mentioned as beneficial applications. Additionally, the mechanisms of toxicity of PLA₂ are presented in detail. Finally, a number of anti-PLA₂ compounds are enumerated. In each section, the features of the honeybee venom molecule are discussed in relation to PLA₂s from other species. Full article

An experimental model of acute pulmonary damage was developed based on the intravenous injection of the phospholipase A₂ (PLA₂)-rich venom of Pseudechis papuanus (Papuan black snake) in mice. Venom caused pulmonary edema, with the accumulation of a protein-rich exudate, as observed histologically and by analysis of bronchoalveolar lavage fluid (BALF). In parallel, venom induced an increase in all of the pulmonary mechanical parameters evaluated, without causing major effects in terms of tracheal and bronchial reactivity. These effects were abrogated by incubating the venom with the PLA₂ inhibitor varespladib, indicating that this hydrolytic enzyme is responsible for these alterations. The venom was cytotoxic to endothelial cells in culture, hydrolyzed phospholipids of a pulmonary surfactant, and reduced the activity of angiotensin-converting enzyme in the lungs. The pretreatment of mice with the nitric oxide synthase inhibitor L-NAME reduced the protein concentration in the BALF, whereas no effect was observed when mice were pretreated with inhibitors of cyclooxygenase (COX), tumor necrosis factor-α (TNF-α), bradykinin, or neutrophils. Based on these findings, it is proposed that the rapid pathological effect of this venom in the lungs is mediated by (a) the direct cytotoxicity of venom PLA₂ on cells of the capillary–alveolar barrier, (b) the degradation of surfactant factor by PLA₂, (c) the deleterious action of nitric oxide in pulmonary tissue, and (d) the cytotoxic action of free hemoglobin that accumulates in the lungs as a consequence of venom-induced intravascular hemolysis. Our findings offer clues on the mechanisms of pathophysiological alterations induced by PLA₂s in a variety of pulmonary diseases, including acute respiratory distress syndrome (ARDS). Full article

The occurrence of antibiotic-resistant bacteria is a serious global health issue, and it emphasizes the need for novel antimicrobial agents. This review explores the potential of snake venom as another alternative strategy against antimicrobial resistance. Snake venoms are complex combinations of bioactive peptides and proteins, including metalloproteases (MPs), serine proteases (SPs), phospholipase A₂ (PLA₂) enzymes, three-finger toxins (3FTXs), cysteine-rich secretory proteins (CRISPs), L-amino acid oxidases (LAAOs), and antimicrobial peptides (AMPs). The antibacterial products possess wide-spectrum antibacterial activity against resistant microbes via diverse mechanisms such as cell membrane disruption, enzymatic hydrolysis of microbial structures, generation of oxidative stress, inhibition of biofilms, and immunomodulation. Strong antimicrobial activity is reported by most studies, but these are mostly restricted to in vitro testing with low translational use. Although preliminary insights into molecular targets and physiological effects exist, further studies are needed to clarify long-term safety and therapeutic potential. Special attention is given to snake venom-derived extracellular vesicles (SVEVs), which enhance the therapeutic potential of venom toxins by protecting them from degradation, improving bioavailability, and facilitating targeted delivery. Furthermore, innovative delivery strategies such as PEGylation, liposomes, hydrogels, microneedle patches, biopolymer films, and nanoparticles are discussed for their role in reducing systemic toxicity and enhancing antimicrobial efficacy. The rational modification of venom-derived peptides further expands their therapeutic utility by improving pharmacokinetics and minimizing off-target effects. Together, these approaches highlight the translational potential of snake venom-based therapies as next-generation antimicrobials in the fight against resistant infections. By outlining these challenges and directions, this review positions snake venom as an overlooked but fertile resource in the battle against antibiotic resistance. Full article

Plant compounds that inhibit snake venom activities are relevant and can provide active molecules to counteract snake venom effects. Numerous studies on snake viperid venoms found that metalloproteinases play a significant role in the pathophysiology of hemorrhage that occurs on envenomation. Preclinical studies using vitro and in vivo protocols investigated natural compounds and viperid snake venoms, evaluating the enzymatic, procoagulant, hemorrhagic, edematogenic, myotoxic, and lethal activities. Many studies focused on Bothrops venoms and ascribed that angiorrhexis and hemorrhage resulted from the metalloproteinase action on collagen in the basal lamina. This effect resulted in a combined action with phospholipase A2 and hyaluronidase, inducing hemorrhage, edema, and necrosis. Due to the lack of efficient antivenoms in remote areas, traditional native plant treatments remain common, especially in the Amazon. Our group studied plant extracts, isolated compounds, and lapachol synthetic derivative analogs with selective inhibition for Bothrops venom proteolytic and hemorrhagic activity and devoid of phospholipase activity. We highlight those new synthetic naphthoquinones which inhibit snake venom metalloproteinases and that are devoid of other venom enzyme inhibition. This review shows the potential use of snake venom effects, mainly Bothrops venom metalloproteinase activity, as a tool to identify and develop new active molecules against hemorrhagic effects. Full article

Examination of venom constituent bioactivities from diverse venomous animals shows certain highly conserved classes, including enzymes (e.g., phospholipases and metalloproteinases) and pore-forming proteins. While antivenoms targeting other unique and lethal venom components have proven to be life-saving, venom-enzyme-driven tissue damage and morbidity persists. Broad-acting enzyme inhibitors demonstrate the potential to augment antivenom approaches. In this study, we investigate the potential utility of certain broad-acting inhibitors in cubozoa for the first time. Fluorogenic assays were used to determine the phospholipase A₂ (PLA₂) and matrix metalloproteinase (MMP) activity of the Hawaiian box jellyfish, Alatina alata, and this was compared to representative elapid, viper, and bee venoms. In vitro, evaluation of selected small-molecule inhibitors demonstrated the ability and feasibility of the broad-acting therapeutic doxycycline, which inhibited the PLA₂ and MMP activity of A. alata (approximately 50% reduction at 0.1 mM (95% CI 0.06–0.15) and 2.1 mM (95% CI 1.4–3.0), respectively), in addition to both snake venoms. Additionally, copper gluconate broadly inhibited the PLA₂ activity of bee, snake, and jellyfish venoms. While all venoms are complex mixtures of bioactive molecules, these studies demonstrate that targeting common class components with broad-acting inhibitors shows promise in clinical and preclinical management. Full article

Dermonecrosis resulting from Loxosceles spider envenomation, primarily driven by the enzyme sphingomyelinase D (SMase D), is characterized by severe inflammation and nonhealing wounds. SMases can be classified as Class I or II based on their structural characteristics. Class I exhibits greater dermonecrotic activity than Class II; however, the intracellular mechanisms responsible for this difference remain poorly understood. The differential transcriptomics analysis of human keratinocytes treated with each toxin revealed that Class I primarily activates pathways associated with proteolytic activity and apoptosis. In contrast, Class II uniquely upregulates key genes, including PIM-1, MCL-1, PAI-1, p21, and c-FOS, which support cell survival and inhibit apoptosis. These pathways also facilitate tissue repair and keratinocyte proliferation during wound healing, particularly through signaling mechanisms involving Substance P and VEGF-A. RT-qPCR confirmed these findings, with protein level evaluations indicating the sustained upregulation of VEGF-A exclusively in keratinocytes treated with Class II. We identified Substance P and VEGF-A as potential therapeutic targets for managing cutaneous loxoscelism, providing valuable insights into the cellular mechanisms underlying the distinct toxic effects of the two SMase D isoforms. By elucidating these pathways, this study enhances our understanding of loxoscelism’s pathophysiology and highlights strategies for therapeutic intervention in dermonecrotic injuries caused by spider venom. Full article