Abstract in English:

Abstract Background: Spiders of medical importance in the Amazon region belong to the genera Phoneutria, Loxosceles and Latrodectus. Natural history data show that Phoneutria spp. occur in both periodically flooded forest areas (igapós) and non-flooded areas (terra firme), as well as in commercial plantations in the Amazon. Negative interactions with wandering spiders (Phoneutria spp.) can occur along forest trails, leading to homes, schools and workplaces. Harmful species, such as Loxosceles amazonica and Latrodectus aff. curacaviensis, are mainly associated with accidents in rural settings. Methods: 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. Results: 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. Conclusion: 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.

Abstract in English:

Abstract Background: Cancer is one of the leading causes of death worldwide, with incidence rates continuously increasing, thereby posing a major healthcare challenge. Although many oncological drugs fulfill therapeutic requirements, they often show high toxicity due to their limited specificity. To address this problem, there has been a search for natural therapies, including animal venoms that harbor bioactive molecules with therapeutic potential, as well as biological models that facilitate their study. Consequently, three-dimensional culture models, such as spheroids, play a pivotal role in evaluating anticancer molecules, as they can effectively mimic in vivo tumor microenvironments. Methods: This study aimed to establish the significance of spheroids in identifying venom-derived molecules as potential therapeutic alternatives against cancer, based on a systematic review conducted from 2010 to 2024. Following PRISMA guidelines, a systematic search was conducted in four databases using the terms “Spheroid” and “Venom”. Of the 93 articles identified, 16 satisfied the inclusion criteria for this review. Results: Notably, several bioactive molecules derived from snake, spider, scorpion, and bee venoms were evaluated using various spheroid formation methods. These molecules demonstrated cytotoxic effects that impaired spheroid formation and disrupted invasion and migration processes. Conclusion: Overall, the findings indicate that the integration of three-dimensional culture models with venom-derived compounds constitutes a promising preclinical strategy for the development of innovative, venom-based therapeutic strategies for cancer treatment.

Abstract in English:

Abstract The treatment of cutaneous leishmaniasis (CL) is challenged by limited therapeutic options, high drug toxicity, and frequent treatment failure. In this context, iron oxide nanoparticles (IONPs) have emerged as promising therapeutic alternatives. This review summarizes experimental findings on the in vitro and in vivo anti-Leishmania activity of IONPs, highlighting their potential as a treatment for CL. A systematic search of PubMed, ScienceDirect, and Scopus identified 16 studies evaluating the anti-Leishmania effects of IONPs across various CL models. The studies assessed IONPs' physicochemical properties (size, shape, polydispersity index, and zeta potential), functionalization strategies, and efficacy against axenic and intracellular Leishmania forms, as well as in animal models. Most studies investigated spherical IONPs ranging from 5 to 90 nm, with polydispersity index values between 0.2 and 1.0 and zeta potentials from -13 mV to +35 mV. Functionalization improved dispersion and enabled antimicrobial conjugation. IONPs reduced axenic Leishmania viability, decreased intracellular parasitism, and lowered parasite loads in infected mouse lesions. In vitro, parasite death was linked to lysosomal rupture, oxidative stress, apoptosis, necrosis, and nitric oxide production by macrophages. In vivo, treated animals exhibited reduced parasite burdens, milder lesions, and enhanced IFN-γ production, suggesting improved immune responses. Despite these promising effects, issues such as formulation optimization, biocompatibility, and evaluation of pharmacokinetics and pharmacodynamics remain to be addressed. IONPs represent a novel and promising dual-action therapeutic strategy for CL, combining antiparasitic effects with immune modulation. However, important knowledge gaps persist regarding their mechanisms of action, long-term safety, efficacy across different Leishmania species and clinical scenarios. Further research is needed to advance IONPs as a safe and effective treatment for CL.

Abstract in English:

Abstract Cnidarian venom toxins have attracted increasing interest due to their remarkable molecular diversity and pharmacological potential. Omics technologies - such as genomics, transcriptomics, proteomics, and metabolomics - have facilitated the identification of toxin-encoding genes, providing key insights into their evolutionary trajectories and structure-function relationships, which are essential for understanding their mechanisms of action and therapeutic value. Nevertheless, the functional validation and production of complex toxins remain challenging, particularly for those requiring intricate folding or post-translational modifications. Recombinant expression has emerged as a strategic alternative to traditional purification methods, enabling controlled toxin production and the possibility of modifying their properties through genetic engineering. In parallel, advances in synthetic biology, such as cell-free protein synthesis systems, are creating new opportunities for toxin characterization, although their industrial scalability remains limited. Computational tools, including those based on artificial intelligence, are beginning to support the prioritization and functional analysis of toxins identified through omics approaches. This review provides an updated overview of the advances, limitations, and future perspectives in cnidarian toxin research, highlighting their promising role as a valuable source of bioactive compounds with therapeutic and biotechnological applications.

Abstract in English:

Abstract Background: Fish venoms have been poorly characterized and the available information about their composition suggests they are uncomplicated secretions that, combined with epidermal mucus, could induce an inflammatory reaction, excruciating pain, and, in some cases, local tissue injuries. Methods: In this study, we characterized the 24-hour histopathological effects of lionfish venom in a mouse experimental model by testing the main fractions obtained by size exclusion-HPLC. By partial proteomics analysis, we also correlated these in vivo effects with the presence of some potentially toxic venom components. Results: We observed a strong lesion on the skin and evident necrosis in the skeletal muscle. None of the tissue-damaging effects were induced by the fraction containing cytolysins, membrane pore-forming toxins ubiquitously present in species of scorpionfish, stonefish, and lionfish, among others. On the contrary, injuries were associated with the presence of other components, which have remained practically ignored so far. This is the case of an abundant protein, present in venom, with homology to a Golgi-associated plant pathogenic protein 1-like (GAPR1), which belongs to the same protein superfamily as venom CRISPs and insect allergens. Conclusion: This GAPR1-like protein and the hyaluronidase are probably responsible for the hemostasis impairment and hemorrhagic lesions observed in mouse skin, whereas muscle injuries can be indirectly caused by a combination of inflammatory and hemorrhagic events. More information is required to establish the components accountable for the myonecrotic effect.

Abstract in English:

Abstract Background: Non-small cell lung cancers (NSCLC) represent the primary cause of cancer-related deaths worldwide. Rhopalurus junceus venom has been shown to exert cytotoxic effects against a panel of epithelial cancer cells in vitro and suggested that NSCLC was the subtype most susceptible to the treatment. Methods: This study evaluated the effect of Rhopalurus junceus scorpion venom on cell viability, in non-cancerous (MRC-5, lung; CHO-K1, ovary) and NSCLC (A549; NCI-H460) cell lines. The effects on cell cycle, apoptosis, and cell signaling-related proteins were determined by flow cytometry and WB. Protein fractions responsible for the observed effect were identified using HPLC. Results: Scorpion venom was more effective against NSCLC than non-cancerous cells. Emax values were 20.0 ± 5.8% and 22.47 ± 6.02% in A549 and NCI-H460 cancer cells, respectively, as compared to 50 ± 8.1% in MRC-5 and 54.99 ± 7.39% in CHO-K1 cells. It arrested NSCLC cells in the G2/M phase, while non-cancerous cells were arrested in the S (MRC-5) or G0/G1 (CHO-K1) phases. No changes were observed in the Bax/Bcl-2 or the cleaved-caspase 3/Total caspase 3 ratios in cells treated with venom. Likewise, the scorpion venom treatment did not affect p-ERK, p-AKT, or p-38MAPK protein levels. In contrast, scorpion venom treatment increased the cytosolic apoptosis-inducing factor (AIF) in A549 cells, indicating caspase-independent apoptosis. Additionally, combined etoposide/venom exposure provoked G2/M arrest and apoptosis in NSCLC more strongly than either substance alone. Furthermore, upon crude venom fractioning through RP-HPLC, we found two soluble fractions with high cytotoxic effects. Conclusion: The present study concludes that a specific fraction of Rhopalurus junceus venom reduces cell viability of NSCLC cells. The AIF protein plays a key role in mediating caspase-independent apoptotic cell death. These findings suggest that Rhopalurus junceus venom enhances the anticancer effect of etoposide in vitro by causing cell cycle arrest and caspase-independent apoptosis.

Abstract in English:

Abstract Background: Chagas disease (CD), caused by Trypanosoma cruzi, 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. Methods: Cruzain and AsCystatin were obtained recombinantly through expression in E. coli. Bioinformatic assays were conducted with both molecules, followed by in vitro enzyme inhibition assays. Subsequently, in silico 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 in vitro were finally assessed. Results: AsCystatin, a potential inhibitor of cysteine proteases, was identified from previously published scientific literature. In silico 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 in-silico 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 T. cruzi in in vitro models. Conclusion: 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 in vitro assays.

Abstract in English:

Abstract Background: 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. Methods: Eleven adult monocled cobras (Naja kaouthia 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. Results: 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. Conclusion: 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 N. kaouthia, particularly phospholipase A2 component.

Abstract in English:

Abstract Background: 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. Methods: 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. Results: 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. Conclusion: 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.

Abstract in English:

Abstract Background: 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 Crotalus durissus terrificus venom, as a potential inhibitor of the enzyme trypanothione reductase from Leishmania braziliensis (LbTR). Methods: In silico assays were conducted to evaluate the interaction of crotapotin with LbTR using molecular docking and molecular dynamics techniques. Recombinant LbTR was expressed in E. coli, and its enzymatic activity was confirmed. The inhibitory action of crotapotin on LbTR was then tested in enzymatic assays. Results: 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. Conclusion: The in silico findings suggest a stable and structured interaction between crotapotin and LbTR, with low structural fluctuation, although the inhibition observed in in vitro 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.

Abstract in English:

Abstract Background: 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. Methods: 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. Results: 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. Conclusion: 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.

Abstract in English:

Abstract Background: Deinagkistrodon acutus, 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. Methods: 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. Results: Immunization with ProMPLA and p2AMPLA produced robust antibody responses in mice, effectively inhibiting MPs and PLA2s. In vitro 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. Conclusion: The EpiMPLA epitope represents a promising candidate for generating neutralizing antibodies against D. acutusvenom, 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.

Abstract in English:

Abstract Background: 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. Methods: 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). Results: 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 R. diptycha ranged from 478 to 801 mg of EqMB/g of extract, while the R. granulosa sample presented 661 mg of EqMB/g of extract. Conclusion: 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.

Abstract in English:

Abstract Background: 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 Potamotrygon orbignyi, the toadfish Thalassophryne nattereri, the scorpionfish Scorpaena plumieri, and the catfish Pseudoplatystoma fasciatum and Cathorops spixii. Methods: We comprehensively searched reports about accidents involving venomous fish in Brazil and compared the toxic activities of some medically relevant species. Results: 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. T. nattereri venom presents greater toxicity, causing more severe local responses than that of P. orbignyi, C. spixii, and P. fasciatum, which cause moderate reactions. The S. plumieri venom induced only a moderate level of edema and could not cause nociception or necrosis. These results highlight that envenomation by P. orbigny, C. spixii, and S. plumieri is marked by proteins with intense hemolytic/proteolytic and phospholipase activity. On the other hand, T. nattereri and P. fasciatum offered a broader panel of new toxin families. Conclusion: 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.

Abstract in English:

Abstract Background: Snake venom C-type lectin-like proteins (also known as snaclecs) have anticoagulation and procoagulation effects by targeting platelet or coagulation factor IX/X, suggesting their potential as candidates for new anticoagulant drugs. Therefore, this study aims to evaluate the antiplatelet and antithrombotic effects of a new snaclec from Protobothrops mucrosquamatus venom and its potential as an anticoagulant candidate. Methods: Promucetin was purified through sequential column chromatography, and its molecular mass was determined by SDS-PAGE. The α- and β-chains of promucetin were identified using liquid chromatography-mass spectrometry (LC-MS). In vitro analyses of platelet aggregation were performed using turbidimetric methods, thromboelastography, and coagulation activity assays. For in vivo experiments, promucetin was administered to rats at varying concentrations, and platelet changes were monitored. The antithrombotic effects of promucetin were assessed using a FeCl₃-induced rat thrombosis model. Results: Promucetin existed as two multimers with molecular weights of 140.1 kDa and 91.9 kDa under non-reducing conditions. Sequence analysis revealed that its α-chain and β-chain shared 71% and 34% homology, respectively, with TMVA from the same snake venom. In vitro platelet aggregation assays indicated that promucetin activated platelets via glycoprotein Ib. Thromboelastography showed that promucetin inhibited both coagulation factor activity and platelet function, resulting in an anticoagulant effect. Specifically, thrombin time was prolonged, while activated partial thromboplastin time and prothrombin time remained unchanged. In vivo, promucetin administration led to a dose-dependent decrease in platelet count. At doses of 25 and 50 μg/kg, promucetin significantly inhibited thrombosis, with inhibition rates of 40.9% and 74.4%, respectively. For comparison, lysine acetylsalicylate produced an inhibition rate of 36.7%. Conclusion: Promucetin exhibits significant ability to modulate coagulation function and effectively inhibit thrombosis by activating platelet via GPIb and reducing platelet count, which helps us understand its biological function in snake bites, it exhibits the potential to be a candidate for anticoagulant therapy.

Abstract in English:

Abstract Background: Acute kidney injury (AKI) is a serious complication associated with Daboia siamensis envenomation, primarily due to direct nephrotoxicity. This study aimed to investigate the effects of the phospholipase A2 (RvPLA₂) fraction from D. siamensis venom on renal function and to assess whether pretreatment with ion channel blockers could mitigate these effects using an isolated perfused kidney (IPK) model. Methods: Twenty IPKs were allocated into five groups (n = 4 each): (1) RvPLA₂ in calcium-deficient modified Krebs-Henseleit solution (MKHS), (2) RvPLA₂ in standard MKHS, (3) RvPLA₂ following pretreatment with verapamil (a voltage-gated Ca²⁺ channel blocker), (4) RvPLA₂ following pretreatment with amiloride (a Na⁺ channel blocker), and (5) RvPLA₂ following pretreatment with minoxidil (a KATP channel opener). Renal function parameters were assessed accordingly. Results: Administration of 280 μg of RvPLA₂ in calcium-deficient MKHS caused no significant changes in renal function. In contrast, RvPLA₂ in standard MKHS (1.9 mM Ca²⁺) significantly increased perfusion pressure (PP), renal vascular resistance (RVR), and free water excretion (p < 0.05), while non-significant increases were observed in glomerular filtration rate (GFR), urinary flow rate (UF), osmolar clearance (Cosm), and the fractional excretion of sodium (FENa⁺) and potassium (FEK⁺). Verapamil alone caused significant increases in GFR and Cosm (p < 0.05) and non-significant increases in PP, RVR, UF, FENa⁺, and free water excretion. Amiloride and minoxidil alone did not alter renal function. Pretreatment with verapamil, amiloride, or minoxidil failed to prevent the renal functional changes induced by RvPLA₂. Conclusions: The RvPLA2 activity requires Ca2+ for activation which may target distinct sites on the cell membrane, including ion channel receptors in nephrons. The effects of RvPLA2 on glomerular and renal tubular function are independent and cannot be modified by pretreatment with different ion channel blockers.

Abstract in English:

Abstract Background: Inflammation plays a critical role in the pathogenesis of limb injury caused by Deinagkistrodon acutus snakebite. Investigating its regulatory mechanisms and intervention strategies may help identify effective treatments. Recent studies have shown that pyroptosis exacerbates organ damage by amplifying inflammatory responses. Additionally, immune and matrix-regulatory cells (IMRC), a novel type of mesenchymal stem cell, and their exosomes (Exo) have demonstrated potential in mitigating inflammation-mediated injury by suppressing pyroptosis. This study aimed to evaluate whether IMRC-Exo could alleviate D. acutus venom-induced limb injury in rabbits by suppressing pyroptosis, thereby attenuating the associated inflammatory response. Methods: Eighteen healthy male New Zealand white rabbits were randomly assigned to Sham, Model, and IMRC-Exo groups. The Model group was established by intramuscular injection of D. acutus venom (1.5 mg/kg), followed by intravenous snake antivenom (80 U/kg) after 2 hours. The IMRC-Exo group received IMRC-Exo (7.5 × 1010 particles) post-modeling. Within 24 hours, left thigh circumference, serum creatine kinase (CK), and myoglobin (Mb) were assessed. Muscle tissues were collected for histopathology, apoptosis analysis, inflammatory cytokine quantification [high-mobility group box 1 (HMGB1), IL-1β, IL-18], and pyroptosis-related protein detection [caspase-3, cleaved caspase-3, gasdermin E (GSDME), N-terminal GSDME (N-GSDME)]. Results: Compared to Sham, venom injection significantly increased thigh circumference, CK, Mb, histopathological damage, apoptosis, inflammatory cytokines, and pyroptosis-related proteins. IMRC-Exo significantly reduced these indicators, mitigating muscle injury and inflammation. Additionally, inflammatory cytokines and pyroptosis markers were significantly lower in the IMRC-Exo group than in the Model group. Conclusion: IMRC-Exo effectively alleviates D. acutus venom-induced limb injury in rabbits, likely through inhibition of GSDME-dependent pyroptosis-mediated inflammation. These findings suggest that IMRC-Exo may serve as a promising therapeutic approach for snakebite-induced inflammatory injury.

Abstract in English:

Abstract Background: Scorpion venom contains a variety of toxin molecules that are the drivers of inflammation and oxidative stress, leading to significant tissue damage. While several mechanisms underlying these responses have been studied, the involvement of the proteasome complex - a key regulator of inflammation - remains poorly understood. This study explored the role of the proteasome in modulating inflammatory and oxidative responses to envenomation by Androctonus australis hector venom. Methods: Mice were pretreated intraperitoneally with bortezomib, a proteasome inhibitor, at low (0.05 mg/kg), medium (0.25 mg/kg), or high (0.5 mg/kg) doses, 30 minutes prior to sublethal venom administration (0.5 mg/kg, subcutaneous). Twenty-four hours after venom administration, animals were euthanized, blood and organs were collected to evaluate vascular permeability (via Evans blue dye extravasation), the extent of inflammatory cell infiltration (myeloperoxidase and eosinophil peroxidase enzymatic activities), and oxidative/nitrosative stress markers (nitric oxide, hydrogen peroxide, malondialdehyde, catalase activity, and glutathione). Histopathological examinations were performed to identify structural alterations, such as edema, hemorrhage, and cellular infiltration. Biochemical parameters reflecting organ function, including serum levels of CPK, LDH, ALT, ALP, urea, and creatinine, were also measured to assess the degree of systemic damage. Results: Our findings revealed a dose-dependent immune-modulatory role of the proteasome system. A medium dose of bortezomib reduced inflammatory and oxidative stress markers, such as vascular permeability, eosinophil peroxidase, neutrophil peroxidase, nitric oxide, and malondialdehyde in renal tissue, suggesting a reduction in local inflammation and oxidative damage. In contrast, a higher dose showed pronounced preventive effects in cardiopulmonary and hepatic tissues, significantly reducing inflammatory mediators and oxidative markers, restoring antioxidant enzyme activity (catalase) and glutathione, as well as, improving tissue structure and organ function. Conclusion: These findings underscore the proteasome involvement in inflammatory regulation, likely through modulation of vascular permeability, immune cell activation, and oxidative stress, making it a key target in scorpion envenomation.

Abstract in English:

ABSTRACT Background: The COVID-19 pandemic exposed vulnerabilities in traditional disease surveillance systems, particularly in data reporting and contact tracing. Telemedicine emerged as a promising approach to expand remote access to healthcare. This study aimed to evaluate a newly implemented telemedicine system designed to manage patients with COVID-19, reduce hospital overload, enable early case detection and isolation, ensure rapid response to clinical deterioration, simplify medical records, and provide ongoing patient support. Methods: A prospective cohort study was conducted using the E-care telemedicine system to assist adult patients presenting with COVID-19 symptoms at a Brazilian university between June 2021 and June 2024. Results: The E-care system delivered care to 6,129 patients, predominantly female, white university students. Physicians attended over 80% (4,903/6,129) of patients and prescribed medications to nearly 28% (1,411/5,041). Medical certificates for time off work were issued to 43% (2,635/6,129) of participants. COVID-19 tests were recommended for approximately 24% of patients, with a positivity rate above 81% among those who returned results. Only 66 patients (1.2%) required in-person care, and no COVID-19-related deaths were reported. Patient satisfaction was high, with 96% (5,584/6,129) expressing satisfaction or high satisfaction with the service. Conclusions: This study provides robust evidence supporting the successful implementation of a telemedicine system for managing COVID-19 cases. The large number of users highlights an unmet demand for virtual healthcare. Telemedicine was rapidly adopted, achieved high patient satisfaction, and contributed to reducing hospital burden, promoting early detection, and minimizing in-person consultations. These findings reinforce the value of telemedicine as an essential tool for health systems and policymakers to strengthen care delivery beyond the pandemic.

Abstract in English:

Abstract Background: 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. Case Presentation: 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. Conclusion: 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.

Abstract in English:

Abstract Background: Paracoccidioidomycosis (PCM) is a systemic mycosis endemic to Latin America, with the acute/subacute form predominantly affecting children and young adults. Cases of cecal appendicitis caused by Paracoccidioides spp. have rarely been reported. This study aimed to describe the clinical manifestations and evolution of a case of cecal appendicitis due to PCM and to conduct a systematic literature review. Case presentation: We present the case of a 20-year-old male with generalized lymphadenopathy who was diagnosed with PCM and treated with oral trimethoprim-sulfamethoxazole. After the initial improvement, the patient returned with clinical deterioration. The treatment was changed to liposomal amphotericin B. Six days later; the patient developed an acute abdomen and underwent exploratory laparotomy with appendectomy. Histopathological examination confirmed acute granulomatous appendicitis due to PCM, and the patient showed postoperative clinical improvement. A systematic review were conducted using Embase, Web of Science, Lilacs, Medline, LIEPCS, PubMed, SciELO, and Gray Literature databases. Of the ten identified articles included in the systematic review, most case reports with a low risk of bias were found in South American countries. Seven patients were confirmed appendicitis due to PCM through biopsy, whereas one had confirmed PCM at another site. Two patients were initially misdiagnosed with Crohn's. Most studies have reported favorable outcomes. Conclusion: Appendicitis caused by PCM is rare, even in endemic countries. It has a benign course when properly treated with both clinical and surgical management. This should be considered in the differential diagnosis of acute abdomen with lymphadenopathy in endemic regions.

Abstract in English:

Abstract Background: This study examines the impact of Phα1β, a spider peptide derived from the venom of Phoneutria nigriventer, on the Kv11.1 potassium channel in HEK293 cells transfected with the human ERG potassium channel. Phα1β inhibits high-voltage calcium channels and acts as an antagonist of the TRPA1 receptor, both of which play crucial roles in pain transduction pathways. Over the past 15 years, our research has demonstrated the potential of Phα1β, in both its native and recombinant forms, as a promising analgesic drug through preclinical tests conducted on rodent pain models. Regulatory agencies require the evaluation of new drugs on human ERG channels. Methods: To assess hERG potassium channel inhibition, we utilized the FLIPR® Potassium Assay, a commercially available kit. The assay involved testing the effects of Phα1β alongside the well-established hERG potassium channel blocker dofetilide, which served as a positive control. The viability of HEK-293 cells was assessed using the colorimetric MTT reduction test (3-(4, dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), whereby viable cells reduce the MTT salt, forming a formazan complex within their mitochondria, as previously described. Results: Phα1β was tested at concentrations of 56, 225, 450, and 900 pMol, resulting in a discreet inhibition of hERG potassium channel activity at higher concentrations, approximately 13.47%, with an IC50 value exceeding 900 pMol. Dofetilide, administered at concentrations ranging from 0.0001 to 10 µM, displayed a concentration-dependent inhibition of the hERG potassium channel, with a mean IC50 value of 0.1642 µM (0.1189-0.2282 µM). To evaluate cytotoxicity, HEK293-hERG cells were exposed to Phα1β concentrations of 56/900 pMol for 24 hours, resulting in no significant alteration in cell viability. Conclusion: Our findings indicate that even at high concentrations, Phα1β does not impede the functionality of the hERG potassium channel nor affect cell viability.