Journal of Venomous Animals and Toxins Including Tropical Diseases最新文献

{"title":"Translational science at the undergraduate level: awakening talents to overcome the valley of death - case report.","authors":"Rui Seabra Ferreira, Cristina Kampus Mantovani, Ana Silvia Sartori Barraviera Seabra Ferreira, Laura de Oliveira Nascimento, Merari de Fátima Ramires Ferrari, Daniel Fabio Kawano, Katlin Brauer Massirer, Gabriel Forato Anhê, Rosley Anholon, Celso Pereira Caricati, Luciane Meneguin Ortega, Sarah Guilbert, Teresa Lambe, José Paes Oliveira-Filho, Sue Ann Costa Clemens, Benedito Barraviera","doi":"10.1590/1678-9199-JVATITD-2025-0005","DOIUrl":"10.1590/1678-9199-JVATITD-2025-0005","url":null,"abstract":"<p><strong>Background: </strong>In the biomedical field, translational science is the process of applying basic scientific knowledge to advance clinical research through the creation of new drugs, devices, medical procedures, preventive measures, and diagnostic kits. The Covid-19 pandemic exposed a shortage of professionals trained in translational research, essential for responding to global demands. To drive advancements, researchers must overcome the 'valley of death', a critical phase in clinical investigation. In response, CEVAP at São Paulo State University (UNESP), Botucatu, Brazil, has developed a strong 'knowledge industry' centered on Translational Science. As part of its research and innovation efforts, CEVAP has developed two biopharmaceuticals, the fibrin sealant and the apilic antivenom, which are currently in the final stage of development. In 2024, CEVAP began the first Brazilian Contract Development and Manufacturing Organization (CDMO) for developing and producing validated and qualified pilot-scale batches to generate clinical trial material.</p><p><strong>Case presentation: </strong>The implementation of the optional undergraduate course in Translational Science marks a crucial step in strengthening the 'knowledge industry'. The program, developed in collaboration with São Paulo's three public universities (USP, UNESP, and UNICAMP), also involves an international partnership with the University of Oxford's Department of Pediatrics and the Oxford Research Group LATAM. The successful launch of this course underscores its importance in interdisciplinary education and institutional collaboration. By bridging gaps between research and application, the program equips professionals to meet the growing demand for expertise in translational science. Given the project's success, it will transition into a one-year 'Qualification in Translational Science', available to students enrolled in São Paulo state universities.</p><p><strong>Conclusion: </strong>The preparation of these professionals will be strategic for transforming basic research into products for health, saving lives, and combating future pandemics that will emerge around the world.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20250005"},"PeriodicalIF":1.8,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12105585/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144150877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive overview of fish envenomation and venom toxicity in Brazil.","authors":"Mônica Lopes-Ferreira, Felipe Justiniano Pinto, Yasmin Stefanie Oliveira Costa, Alessa Aparecida Burgarelli, Louise Lene Gomes Lima, Bibiana da Silva Marques, Carla Simone Seibert, Elineide Eugenio Marques, Patrícia Charvet, Vidal Haddad, João Gabriel Dos Santos Rosa, Geonildo Rodrigo Disner, Carla Lima","doi":"10.1590/1678-9199-JVATITD-2024-0061","DOIUrl":"10.1590/1678-9199-JVATITD-2024-0061","url":null,"abstract":"<p><strong>Background: </strong>Brazilian waters are home to various venomous fish species, each with its unique venom composition. Although common, envenomation cases are largely underreported, leading to a lack of public health policies for prevention and treatment. Some of the most clinically relevant fish in Brazil include the stingray <i>Potamotrygon orbignyi</i>, the toadfish <i>Thalassophryne nattereri</i>, the scorpionfish <i>Scorpaena plumieri</i>, and the catfish <i>Pseudoplatystoma fasciatum</i> and <i>Cathorops spixii</i>.</p><p><strong>Methods: </strong>We comprehensively searched reports about accidents involving venomous fish in Brazil and compared the toxic activities of some medically relevant species.</p><p><strong>Results: </strong>From the biochemical and toxicological evaluation, we found that venoms show a hierarchy in the ability to induce local toxic effects in mice, probably related to the venom compound diversity with species-specific toxins. <i>T. nattereri</i> venom presents greater toxicity, causing more severe local responses than that of <i>P. orbignyi</i>, <i>C. spixii</i>, and <i>P. fasciatum</i>, which cause moderate reactions. The <i>S. plumieri</i> venom induced only a moderate level of edema and could not cause nociception or necrosis. These results highlight that envenomation by <i>P. orbigny</i>, <i>C. spixii</i>, and <i>S. plumieri</i> is marked by proteins with intense hemolytic/proteolytic and phospholipase activity. On the other hand, <i>T. nattereri</i> and <i>P. fasciatum</i> offered a broader panel of new toxin families.</p><p><strong>Conclusion: </strong>Knowledge of fish venom biochemical and toxicological activities is crucial to antivenom therapy development and helps endorse the study of venomous fish and their impact on the public health system.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240061"},"PeriodicalIF":1.8,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12088643/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144102124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and validation of a spectrophotometric method for the quantification of total bufadienolides in samples of toad glandular secretions.","authors":"Elcio Daniel Sousa Barros, Evaldo Dos Santos Monção, Mariana Helena Chaves, Cícero Alves Lopes, Gerardo Magela Vieira","doi":"10.1590/1678-9199-JVATITD-2024-0064","DOIUrl":"10.1590/1678-9199-JVATITD-2024-0064","url":null,"abstract":"<p><strong>Background: </strong>Bufadienolides are the main secondary metabolites found in the paratoid gland secretions (PGS) of toads of the Bufonidae family. These compounds are considered the main bioactive components of PGS. The aim of this study was to develop and validate the first method for the quantification of total bufadienolides (free and esterified) in samples of paratoid secretions from toads, using the UV-Vis absorption spectrophotometry technique.</p><p><strong>Methods: </strong>The proposed method was based on the bathochromic shift induced by the reaction of the α-pyrone group of bufadienolides (296 nm) with a 5% (w:v) aqueous solution of sodium hydroxide and detection at 356 nm, after 60 min (time defined based on the evaluation of kinetic assays).</p><p><strong>Results: </strong>The proposed method showed wide linearity (r = 0.9999), low LOD (1.3 × 10^-4 µg/mL) and LOQ (3.9 × 10^-4 µg/mL), recovery (84%-99%), repeatability (%RSD ≤ 5), reproducibility and robustness (p > 0.05). The total bufadienolide content in PGS extracts from 12 samples of <i>R. diptycha</i> ranged from 478 to 801 mg of EqMB/g of extract, while the <i>R. granulosa</i> sample presented 661 mg of EqMB/g of extract.</p><p><strong>Conclusion: </strong>The new developed method is innovative, simple, fast, accurate, robust, low cost, and can contribute to future research focused on the quantification of total bufadienolides in samples of toad glandular secretions. In addition to serving as a strategic tool in the selection of work matrices, optimizing time, and minimizing costs.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240064"},"PeriodicalIF":1.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12092071/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144111102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Epitope-based antibody development against metalloproteinases and phospholipases A₂ from <i>Deinagkistrodon acutus</i> venom.","authors":"Haiting Zhu, Yuexin Pan, Zhiyuan Tai, Mingqian Wang, Xia Liu, Xiaodong Yu, Qiyi He","doi":"10.1590/1678-9199-JVATITD-2024-0060","DOIUrl":"https://doi.org/10.1590/1678-9199-JVATITD-2024-0060","url":null,"abstract":"<p><strong>Background: </strong><i>Deinagkistrodon acutus</i>, or the hundred-pace snake, poses severe health risks due to its venom. Envenomation by this snake leads to complications such as hemorrhage, edema, and coagulopathy. Traditional antivenoms are limited by venom variability and often contain non-neutralizing antibodies, highlighting the need for more precise and effective immunogens.</p><p><strong>Methods: </strong>This study utilized epitope-based antibody technology to develop a targeted sera against venom metalloproteinases (MPs) and phospholipases A₂ (PLA₂s). Twelve antigenic epitopes were identified via bioinformatics, leading to the design of a composite antigen peptide, EpiMPLA. It was engineered to be expressed via two expression systems, resulting in the recombinant immunogens, ProMPLA and p2AMPLA.</p><p><strong>Results: </strong>Immunization with ProMPLA and p2AMPLA produced robust antibody responses in mice, effectively inhibiting MPs and PLA₂s. <i>In vitro</i> assays demonstrated that sera from immunized mice reduced the activity of these venom enzymes, minimized venom-induced hemorrhage and edema, and restored blood coagulation. At a venom dose of 2×LD₅₀, all mice in the control group died, while survival rates were 90% for anti-ProMPLA and 70% for anti-p2AMPLA.</p><p><strong>Conclusion: </strong>The EpiMPLA epitope represents a promising candidate for generating neutralizing antibodies against <i>D. acutus</i>venom, demonstrating its potential to address critical gaps in current antivenom therapy. These findings not only validate the feasibility of epitope-based antivenom development but also pave the way for further research to optimize this strategy.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240060"},"PeriodicalIF":1.8,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12063738/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Melittin inhibits proliferation, migration, and invasion in osteosarcoma cell lines using 2D and 3D models.","authors":"Giovana Pedro, Felipe César da Silva Brasileiro, Rui Seabra Ferreira, Aline Márcia Marques Bráz, Renée Laufer-Amorim","doi":"10.1590/1678-9199-JVATITD-2024-0053","DOIUrl":"https://doi.org/10.1590/1678-9199-JVATITD-2024-0053","url":null,"abstract":"<p><strong>Background: </strong>Osteosarcoma is the most common primary bone tumor in humans. It is a locally aggressive tumor at the primary site, with metastasis being the main cause of death in patients. Studies on dogs have gained prominence in oncology, as they are valuable spontaneous models of osteosarcoma. In the context of natural compounds, biotoxins are attracting increasing research interest as new therapeutic agents against cancer, such as melittin, that represents 40 to 50% of the dry weight of bee venom, and studies have already shown its antitumor effects.</p><p><strong>Methods: </strong>We analyzed the anti-migratory and anti-invasive potential of melittin, with the wound healing and Transwell tests, apoptosis with Annexin V/IP and cell viability with the MTT test in 2D and 3D models.</p><p><strong>Results: </strong>Melittin had a cytotoxic effect on osteosarcoma cell lines, with an IC50 between 1.5 and 2.5 µg/mL. In the wound healing test and Transwell test, melittin prevented cell migration and invasion, resulting in cell death due to iodide propidium marking in canine, murine and human cell lines. Melittin exhibited cytotoxicity in a 3D model of osteospheres, with a significantly higher IC50 in this type of culture, with values between 3.5 and 4.0 µg/mL.</p><p><strong>Conclusion: </strong>We conclude that melittin has antitumor and antimetastatic properties in canine, murine and human osteosarcoma cell lines. Consequently, we believe that further research on this promising compound will facilitate its application in the development of therapeutic agents for osteosarcoma, ultimately contributing to improved survival outcomes for cancer patients.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240053"},"PeriodicalIF":1.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11996085/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144017300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An overview of spider accidents in the Brazilian Amazon.","authors":"Jonas Gama Martins, Pedro Pereira de Oliveira Pardal, Antonio Domingos Brescovit, Rudi Emerson de Lima Procópio","doi":"10.1590/1678-9199-JVATITD-2024-0057","DOIUrl":"https://doi.org/10.1590/1678-9199-JVATITD-2024-0057","url":null,"abstract":"<p><strong>Background: </strong>Spiders of medical importance in the Amazon region belong to the genera <i>Phoneutria</i>, <i>Loxosceles</i> and <i>Latrodectus</i>. Natural history data show that <i>Phoneutria</i> spp. occur in both periodically flooded forest areas (<i>igapós</i>) and non-flooded areas (<i>terra firme</i>), as well as in commercial plantations in the Amazon. Negative interactions with wandering spiders (<i>Phoneutria</i> spp.) can occur along forest trails, leading to homes, schools and workplaces. Harmful species, such as <i>Loxosceles amazonica</i> and <i>Latrodectus</i> aff. <i>curacaviensis</i>, are mainly associated with accidents in rural settings.</p><p><strong>Methods: </strong>To understand the dynamics of spider accidents in the Brazilian Amazon, we conducted a search for scientific articles in five databases (Google Scholar, PubMed/MEDLINE, Scopus by Elsevier and SciELO). In addition, we analyzed the content of four reference books on the ecological aspects of Amazonian spiders. All told, we identified 64 eligible studies, including six regional surveys published between 1996 and 2016.</p><p><strong>Results: </strong>From 2015 to 2022, a total of 25 human lives were lost to spider envenomation in the Brazilian Amazon. An analysis of the data revealed that many riverside families engage in agricultural practices that expose them to venomous animals. Hospital data reveal that most patients bitten by spiders come from impoverished rural communities, which rely on public hospitals of Brazil's Unified Health System (SUS) for medical treatment. The results indicate that spider bites in the Amazon represent a neglected public health problem, especially in locations far from capital cities.</p><p><strong>Conclusion: </strong>Amerindian and non-Amerindian communities living in areas at high risk of venomous animal attacks do not receive adequate attention in health policies. Given the wide dispersion of rural populations vulnerable to venomous animal incidents in the Amazon, the establishment of new referral medical centers is an essential strategy, especially for riverside communities with limited access to health services.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240057"},"PeriodicalIF":1.8,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12023759/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143975158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular interaction assays <i>in silico</i> of crotapotin from <i>Crotalus durissus terrificus</i> against the molecular target trypanothione reductase from <i>Leishmania braziliensis</i>.","authors":"Jamile Mariano Macedo, Mateus Farias Souza, Anderson Maciel Lima, Aleff Ferreira Francisco, Anderson Makoto Kayano, Maria Elisabeth Moreira de Lima Gusmão, Erika Crhistina Santos de Araújo, Guilherme Henrique Marchi Salvador, Marcos Roberto de Mattos Fontes, Juliana Pavan Zuliani, Andreimar Martins Soares","doi":"10.1590/1678-9199-JVATITD-2024-0049","DOIUrl":"10.1590/1678-9199-JVATITD-2024-0049","url":null,"abstract":"<p><strong>Background: </strong>Leishmaniasis is a neglected disease that mainly affects impoverished populations and receives limited attention from governments and research institutions. Current treatments are based on antimonial therapies, which present high toxicity and cause significant side effects, such as cardiotoxicity and hepatotoxicity. This study proposes using crotapotin, isolated from <i>Crotalus durissus terrificus</i> venom, as a potential inhibitor of the enzyme trypanothione reductase from <i>Leishmania braziliensis</i> (LbTR).</p><p><strong>Methods: </strong><i>In silico</i> assays were conducted to evaluate the interaction of crotapotin with LbTR using molecular docking and molecular dynamics techniques. Recombinant LbTR was expressed in <i>E. coli</i>, and its enzymatic activity was confirmed. The inhibitory action of crotapotin on LbTR was then tested in enzymatic assays.</p><p><strong>Results: </strong>The stability of these interactions was confirmed over 200 ns molecular dynamics simulations, with a clustering analysis using the GROMACS method revealing a total of 12 distinct clusters. The five most representative clusters showed low RMSD values, indicating high structural stability of the LbTR-crotapotin complex. In particular, cluster 1, with 3,398 frames and an average RMSD of 0.189 nm from the centroid, suggests a dominant stable conformation of the complex. Additional clusters maintained average RMSD values between 0.173 nm and 0.193 nm, further reinforcing the robustness of the complex under physiological conditions. Recombinant LbTR expression was successful, yielding 4.8 mg/L with high purity, as verified by SDS-PAGE. In the enzymatic assays, crotapotin partially inhibited LbTR activity, with an IC₅₀ of 223.4 μM.</p><p><strong>Conclusion: </strong>The <i>in silico</i> findings suggest a stable and structured interaction between crotapotin and LbTR, with low structural fluctuation, although the inhibition observed in <i>in vitro</i> assays was moderate. These results indicate the potential of crotapotin as a promising basis for developing specific LbTR inhibitors, contributing to the bioprospecting of new antiparasitic agents.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240049"},"PeriodicalIF":1.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11970842/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143796018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of envenomation timing on peripheral immune and oxidative responses in experimental scorpion envenomation.","authors":"Fares Daachi, Sonia Adi-Bessalem, Amal Megdad-Lamraoui, Fatima Laraba-Djebari","doi":"10.1590/1678-9199-JVATITD-2024-0059","DOIUrl":"10.1590/1678-9199-JVATITD-2024-0059","url":null,"abstract":"<p><strong>Background: </strong>Scorpion envenomation poses a significant health threat in endemic regions, eliciting complex immune responses in affected individuals. Recent research suggests that the timing of envenomation - whether it occurs during the day or night - may influence the host inflammatory response and subsequent organ damage. This study investigates the impact of envenomation timing on host inflammatory and oxidative responses using an experimental scorpion envenomation model.</p><p><strong>Methods: </strong>Mice were divided into two groups, corresponding to their resting phase (day) and activity phase (night), and were monitored for twenty-four hours post-envenomation. We analyzed systemic inflammatory markers, hormonal changes within the hypothalamic-pituitary-adrenal (HPA) axis, and assessed liver toxicity.</p><p><strong>Results: </strong>Our findings reveal that the release of the myeloperoxidase enzyme, along with the pro-inflammatory cytokines IL-6 and IL-17, varied significantly based on the timing of envenomation. Notably, envenomation occurring during the nighttime resulted in elevated levels of these mediators. We also observed a pronounced imbalance in oxidative stress, characterized by a higher presence of prooxidant species during the daytime and enhanced antioxidant activities during the nighttime. This diurnal variation highlights the dynamic nature of the inflammatory and oxidative processes. Importantly, our analysis points to the probable involvement of corticosterone, the final effector of the HPA axis, in modulating these variations in the inflammatory response. By influencing both the intensity of the immune response and the degree of oxidative stress, corticosterone appears to play a pivotal role in the overall pathophysiology of scorpion envenomation.</p><p><strong>Conclusion: </strong>This study provides valuable insights into how the timing of scorpion envenomation influences inflammatory responses and organ-specific toxicity, offering potential implications for the treatment and management of envenomation cases.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240059"},"PeriodicalIF":1.8,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11960785/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143764488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cystatin from Austrelaps superbus snake venom as a model for identifying potential inhibitors of Trypanosoma cruzi cruzain.","authors":"Jorge Javier Alfonso Ruiz Díaz, Ana Fidelina Gómez Garay, Anderson Makoto Kayano, Rudson Holanda, Aleff Ferreira Francisco, Christian Collins Kuehn, Andreimar Martins Soares, Celeste Vega, Leonardo de Azevedo Calderon","doi":"10.1590/1678-9199-JVATITD-2024-0055","DOIUrl":"10.1590/1678-9199-JVATITD-2024-0055","url":null,"abstract":"<p><strong>Background: </strong>Chagas disease (CD), caused by <i>Trypanosoma cruzi</i>, affects approximately seven million individuals worldwide, with the highest number of cases in Latin America. CD has two phases, of which the chronic phase is characterized by reduced efficacy in drug therapies. This and other factors make developing new strategies that aim to identify molecules capable of becoming alternatives to or complement current chemotherapy vitally important.</p><p><strong>Methods: </strong>Cruzain and AsCystatin were obtained recombinantly through expression in <i>E. coli</i>. Bioinformatic assays were conducted with both molecules, followed by <i>in vitro</i> enzyme inhibition assays. Subsequently, <i>in silico</i> studies allowed for the design of peptides, which were then assessed for molecular interactions with cruzain. The designed peptides were synthesized, and their inhibitory potential on cruzain and their trypanocidal and cytotoxic effects <i>in vitro</i> were finally assessed.</p><p><strong>Results: </strong>AsCystatin, a potential inhibitor of cysteine proteases, was identified from previously published scientific literature. <i>In silico</i> assays suggested that AsCystatin interacts with key regions of cruzain, and was subsequently produced through heterologous expression, obtaining a protein with a high degree of purity. Next, the inhibition of AsCystatin on the activity of cruzain was assessed, observing that approximately 20 µM of cystatin could inhibit 50% of the catalytic activity of the recombinant enzyme. Based on the <i>in-silico</i> analysis performed previously, original, and modified peptides were designed and tested, which allowed for identifying four peptides with inhibitory capacity on the enzymatic activity of cruzain. Finally, three of these peptides showed trypanocidal activity on epimastigote forms of <i>T. cruzi</i> in <i>in vitro</i> models.</p><p><strong>Conclusion: </strong>It was possible to identify AsCystatin and four peptides derived from this protein with inhibitory activity on cruzain, highlighting the trypanocidal effect of these peptides observed in <i>in vitro</i> assays.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240055"},"PeriodicalIF":1.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11832194/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143441132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiological responses of the monocled cobra (<i>Naja kaouthia</i> Lesson, 1831) including venom production, to high ambient temperature exposure.","authors":"Taksa Vasaruchapong, Narongsak Chaiyabutr, Thanida Nampimoon, Sumpun Thammacharoen","doi":"10.1590/1678-9199-JVATITD-2024-0058","DOIUrl":"10.1590/1678-9199-JVATITD-2024-0058","url":null,"abstract":"<p><strong>Background: </strong>Temperature regulation is essentially important for survival of poikilotherms such as snakes. Body temperature is regulated by snakes through behavioral and physiological responses. The global-warming crisis, combined with the need to house large population of snakes in limited spaces, increases the likelihood of exposing snakes to high ambient temperature (HTa), requiring it reliance on physiological responses. This study aimed to study the effect of HTa exposure on physiological responses and venom production, which have rarely been studied.</p><p><strong>Methods: </strong>Eleven adult monocled cobras (<i>Naja kaouthia</i> Lesson, 1831) were divided into two groups. The concurrent control group was housed in a temperature-controlled room, and the heat exposed group was housed in the same room with gradually increasing temperatures (25°C-35°C) for 4 h on four consecutive days. Data were collected 3 days before the experiment as the baseline and then compared with day 1 and day 4 after HTa exposure data representing immediate and prolonged effects. Body temperature, body weight, water intake, heart rate, hematology, plasma biochemistry, body-fluid compartments, hormonal response, heat shock protein expression and venom production were measured.</p><p><strong>Results: </strong>In response to HTa exposure, body temperature and heart rate increased, plasma volume significantly decreased, but water intake increased. Hematocrit and plasma protein progressively decreased in the latter stages of experimentation, but HTa diminished this effect. HTa only increased plasma corticosterone on day 1. Exposure to HTa increased venom protein concentration on day 4 and diminished the decreased proportion effect of frequent venom collection on phospholipase A₂ component.</p><p><strong>Conclusion: </strong>Increased heart rate and fluid shift from the intravascular compartment appeared to be the underlying mechanism for heat dissipation during HTa exposure. Under the study condition, HTa caused heat stress, but the snake could adapt after continued exposure. Additionally, HTa increased venom protein concentration in <i>N. kaouthia</i>, particularly phospholipase A₂ component.</p>","PeriodicalId":17565,"journal":{"name":"Journal of Venomous Animals and Toxins Including Tropical Diseases","volume":"31 ","pages":"e20240058"},"PeriodicalIF":1.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11832193/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143441160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}