RESUMO
Aedes aegypti is the main vector that transmits viral diseases such as dengue, hemorrhagic dengue, urban yellow fever, zika, and chikungunya. Worldwide, many cases of dengue have been reported in recent years, showing significant growth. The best way to manage diseases transmitted by Aedes aegypti is to control the vector with insecticides, which have already been shown to be toxic to humans; moreover, insects have developed resistance. Thus, the development of new insecticides is considered an emergency. One way to achieve this goal is to apply computational methods based on ligands and target information. In this study, sixteen compounds with acceptable insecticidal activities, with 100% larvicidal activity at low concentrations (2.0 to 0.001 mg·L−1), were selected from the literature. These compounds were used to build up and validate pharmacophore models. Pharmacophore model 6 (AUC = 0.78; BEDROC = 0.6) was used to filter 4793 compounds from the subset of lead-like compounds from the ZINC database; 4142 compounds (dG < 0 kcal/mol) were then aligned to the active site of the juvenile hormone receptor Aedes aegypti (PDB: 5V13), 2240 compounds (LE < −0.40 kcal/mol) were prioritized for molecular docking from the construction of a chitin deacetylase model of Aedes aegypti by the homology modeling of the Bombyx mori species (PDB: 5ZNT), which aligned 1959 compounds (dG < 0 kcal/mol), and 20 compounds (LE < −0.4 kcal/mol) were predicted for pharmacokinetic and toxicological prediction in silico (Preadmet, SwissADMET, and eMolTox programs). Finally, the theoretical routes of compounds M01, M02, M03, M04, and M05 were proposed. Compounds M01−M05 were selected, showing significant differences in pharmacokinetic and toxicological parameters in relation to positive controls and interaction with catalytic residues among key protein sites reported in the literature. For this reason, the molecules investigated here are dual inhibitors of the enzymes chitin synthase and juvenile hormonal protein from insects and humans, characterizing them as potential insecticides against the Aedes aegypti mosquito.
Assuntos
Aedes , Dengue , Inseticidas , Infecção por Zika virus , Zika virus , Animais , Biologia Computacional , Inibidores do Crescimento , Humanos , Insetos , Inseticidas/química , Inseticidas/farmacologia , Larva , Simulação de Acoplamento Molecular , Mosquitos VetoresRESUMO
Inflammation is a complex reaction involving cellular and molecular components and an unspecific response to a specific aggression. The use of scientific and technological innovations as a research tool combining multidisciplinary knowledge in informatics, biotechnology, chemistry and biology are essential for optimizing time and reducing costs in the drug design. Thus, the integration of these in silico techniques makes it possible to search for new anti-inflammatory drugs with better pharmacokinetic and toxicological profiles compared to commercially used drugs. This in silico study evaluated the anti-inflammatory potential of two benzoylpropionic acid derivatives (MBPA and DHBPA) using molecular docking and their thermodynamic profiles by molecular dynamics, in addition to predicting oral bioavailability, bioactivity and toxicity. In accordance to our predictions the derivatives proposed here had the potential capacity for COX-2 inhibition in the human and mice enzyme, due to containing similar interactions with the control compound (ibuprofen). Ibuprofen showed toxic predictions of hepatotoxicity (in human, mouse and rat; toxicophoric group 2-arylacetic or 3-arylpropionic acid) and irritation of the gastrointestinal tract (in human, mouse and rat; toxicophoric group alpha-substituted propionic acid or ester) confirming the literature data, as well as the efficiency of the DEREK 10.0.2 program. Moreover, the proposed compounds are predicted to have a good oral bioavailability profile and low toxicity (LD50 < 700 mg/kg) and safety when compared to the commercial compound. Therefore, future studies are necessary to confirm the anti-inflammatory potential of these compounds.
Assuntos
Anti-Inflamatórios não Esteroides/química , Benzoatos/química , Simulação por Computador , Inibidores de Ciclo-Oxigenase 2/química , Ciclo-Oxigenase 2/química , Ibuprofeno/química , Simulação de Acoplamento Molecular , Propionatos/química , Animais , Humanos , Camundongos , RatosRESUMO
Snake venom toxins are related not only in detention, death and the promotion of initial digestion of prey but also due to their different biochemical, structural and pharmacological effects they can result in new drugs. Among these toxins snake venom serine proteases (SVSPs) should be highlighted because they are responsible for inducing changes in physiological functions such as blood coagulation, fibrinolysis, and platelet aggregation. This article presents the first serine protease (SP) isolated from Bothrops brazili: BbrzSP-32. The new SP showed 36 kDa of relative molecular mass and its absolute mass was confirmed by mass spectrometry as 32,520 Da. It presents 79.48% identity when compared to other SVSPs and was able to degrade the α-chain of fibrinogen, in in vitro models, because of this it is considered a SVTLE-A. It showed dose-dependent activity in the process of degradation of fibrin networks demonstrating greater specificity for this activity when compared to its thrombolytic action. BbrzSP-32 demonstrated proteolytic activity on gelatin and chromogenic substrates for serine proteases and thrombin-like enzymes (S-2288 and S-2238 respectively), besides having coagulant activity on human plasma. After pre-incubation with PMSF and benzamidine the coagulant and proteolytic activities on the S-2288 and S-2238 substrates were reduced. BbrzSP-32 shows stability against pH and temperature variations, demonstrating optimum activity between 30 and 40 °C and in the pH range 7.5 to 8.5. A new SP with potential biotechnological application was isolated.
Assuntos
Venenos de Crotalídeos/química , Serina Proteases/isolamento & purificação , Sequência de Aminoácidos , Animais , Bothrops , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Serina Proteases/químicaRESUMO
BACKGROUND: The Combretum leprosum Mart. plant, popularly known as mofumbo, is used in folk medicine for inflammation, pain and treatment of wounds. From this species, it is possible to isolate three triterpenes: (3ß, 6ß, 16ß-trihydroxylup-20(29)-ene) called lupane, arjunolic acid and molic acid. In this study, through preclinical tests, the effect of lupane was evaluated on the cytotoxicity and on the ability to activate cellular function by the production of TNF-α, an inflammatory cytokine, and IL-10, an immuno regulatory cytokine was assessed. The effect of lupane on the enzymes topoisomerase I and II was also evaluated. METHODS: For this reason, peripheral blood mononuclear cells (PBMCs) were obtained and cytotoxicity was assessed by the MTT method at three different times (1, 15 and 24 h), and different concentrations of lupane (0.3, 0.7, 1.5, 6, 3 and 12 µg/mL). The cell function was assessed by the production of TNF-α and IL-10 by PBMCs quantified by specific enzyme immunoassay (ELISA). The activity of topoisomerases was assayed by in vitro biological assays and in silico molecular docking. RESULTS: The results obtained showed that lupane at concentrations below 1.5 µg/mL was not toxic to the cells. Moreover, lupane was not able to activate cellular functions and did not alter the production of IL-10 and TNF-α. Furthermore, the data showed that lupane has neither interfered in the action of topoisomerase I nor in the action of topoisomerase II. CONCLUSION: Based on preclinical results obtained in this study, we highlight that the compound studied (lupane) has moderate cytotoxicity, does not induce the production of TNF-α and IL-10, and does not act on human topoisomerases. Based on the results of this study and taking into consideration the reports about the anti-inflammatory and leishmanicidal activity of 3ß, 6ß, 16ß-trihydroxylup-20(29)-ene, we suggest that this compound may serve as a biotechnological tool for the treatment of leishmaniasis in the future.
Assuntos
Anti-Inflamatórios/toxicidade , Combretum , Leucócitos Mononucleares/efeitos dos fármacos , Triterpenos/toxicidade , Anti-Inflamatórios/farmacologia , DNA Topoisomerases/metabolismo , Flores , Humanos , Interleucina-10/biossíntese , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Triterpenos/farmacologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The pursuit of novel treatment alternatives to address the accumulated resistance to antimicrobials over the years has prompted the scientific community to explore biodiversity, particularly animal venom, as a potential source of new antimicrobial drugs. Snake venoms, with their complex mixtures of components, are particularly promising targets for investigation in this regard. The search for novel molecules exhibiting antimicrobial activity against multidrug-resistant strains is of paramount importance for public health and numerous research groups worldwide. High expectations within the healthcare field are supported by the scientific literature, which highlights the potential development of innovative drugs through in vivo and in vitro application, depending on dose titration. Snake venoms and their molecules and peptides offer exponential possibilities for biotechnological applications as antimicrobial agents. However, many uncertainties and unexplored avenues remain, presenting opportunities for discoveries and research.
RESUMO
Snakebite envenoming is characterized by the injection of a mixture of proteins/toxins present in venom following the bite of a venomous snake. The toxins have potent bioactivity capability to impact different aspects of envenomation evolution. The cascade of immune responses initiated by the participation of venom and/or toxins isolated from snake venom can contribute to the systemic and local inflammatory effects observed in victims of envenomation. To understand envenomation, a deeper comprehension of the numerous cells, mediators, and components that comprise the immune system reaction to the venom components is required. Thus, activities related to the immune response are highlighted in this study, including the initial line of defense of the innate immune response as signals for the complicated reaction led by specialized cells.
Assuntos
Mordeduras de Serpentes , Toxinas Biológicas , Animais , Alarminas , Venenos de Serpentes/toxicidade , Antivenenos/uso terapêutico , SerpentesRESUMO
Animal venoms and their chemical compounds have aroused both empirical and scientific attention for ages. However, there has been a significant increase in scientific investigations in recent decades, allowing the production of various formulations that are helping in the development of many important tools for biotechnological, diagnostic, or therapeutic use, both in human and animal health, as well as in plants. Venoms are composed of biomolecules and inorganic compounds that may have physiological and pharmacological activities that are not related to their principal actions (prey immobilization, digestion, and defense). Snake venom toxins, mainly enzymatic and non-enzymatic proteins, and peptides have been identified as potential prototypes for new drugs and/or models for the development of pharmacologically active structural domains for the treatment of cancer, cardiovascular diseases, neurodegenerative and autoimmune diseases, pain, and infectious-parasitic diseases. This minireview aims to provide an overview of the biotechnological potential of animal venoms, with a focus on snakes, and to introduce the reader to the fascinating world of Applied Toxinology, where animal biodiversity can be used to develop therapeutic and diagnostic applications for humans.
Assuntos
Neoplasias , Venenos de Serpentes , Animais , Humanos , Venenos de Serpentes/química , Serpentes/metabolismo , Proteínas/química , Peptídeos/farmacologia , Neoplasias/tratamento farmacológicoRESUMO
Bothrops venom contains a high amount of secreted phospholipase A2 (sPLA2s) enzymes responsible for the inflammatory reaction and activation of leukocytes in cases of envenoming. PLA2s are proteins that have enzymatic activity and can hydrolyze phospholipids at the sn-2 position, thereby releasing fatty acids and lysophospholipids precursors of eicosanoids, which are significant mediators of inflammatory conditions. Whether these enzymes have a role in the activation and function of peripheral blood mononuclear cells (PBMCs) is not known. Here we show for the first time how two secreted PLA2s (BthTX-I and BthTX-II) isolated from the venom of Bothrops jararacussu affect the function and polarization of PBMCs. Neither BthTX-I nor BthTX-II exhibited significant cytotoxicity to isolated PBMCs compared with the control at any of the time points studied. RT-qPCR and enzyme-linked immunosorbent assays were used to determine changes in gene expression and the release of pro-inflammatory (TNF-α, IL-6, and IL-12) and anti-inflammatory (TGF-ß and IL-10) cytokines, respectively, during the cell differentiation process. Lipid droplets formation and phagocytosis were also investigated. Monocytes/macrophages were labeled with anti-CD14, -CD163, and -CD206 antibodies to assay cell polarization. Both toxins caused a heterogeneous morphology (M1 and M2) on days 1 and 7 based on immunofluorescence analysis, revealing the considerable flexibility of these cells even in the presence of typical polarization stimuli. Thus, these findings indicate that the two sPLA2s trigger both immune response profiles in PBMCs indicating a significant degree of cell plasticity, which may be crucial for understanding the consequences of snake envenoming.
Assuntos
Bothrops , Venenos de Crotalídeos , Fosfolipases A2 Secretórias , Mordeduras de Serpentes , Humanos , Animais , Antivenenos , Leucócitos Mononucleares , Venenos de Serpentes , Poliésteres , Venenos de Crotalídeos/toxicidadeRESUMO
L-Amino acid oxidase (LAAO) is an enzyme found in snake venom that has multifaceted effects, including the generation of hydrogen peroxide (H2O2) during oxidative reactions, leading to various biological and pharmacological outcomes such as apoptosis, cytotoxicity, modulation of platelet aggregation, hemorrhage, and neutrophil activation. Human neutrophils respond to LAAO by enhancing chemotaxis, and phagocytosis, and releasing reactive oxygen species (ROS) and pro-inflammatory mediators. Exosomes cellular nanovesicles play vital roles in intercellular communication, including immune responses. This study investigates the impact of Calloselasma rhodostoma snake venom-derived LAAO (Cr-LAAO) on human neutrophil exosome release, including activation patterns, exosome formation, and content. Neutrophils isolated from healthy donors were stimulated with Cr-LAAO (100 µg/mL) for 3 h, followed by exosome isolation and analysis. Results show that Cr-LAAO induces the release of exosomes with distinct protein content compared to the negative control. Proteomic analysis reveals proteins related to the regulation of immune responses and blood coagulation. This study uncovers Cr-LAAO's ability to activate human neutrophils, leading to exosome release and facilitating intercellular communication, offering insights into potential therapeutic approaches for inflammatory and immunological disorders.
Assuntos
Exossomos , L-Aminoácido Oxidase , Humanos , L-Aminoácido Oxidase/farmacologia , L-Aminoácido Oxidase/metabolismo , Neutrófilos , Exossomos/metabolismo , Peróxido de Hidrogênio/farmacologia , Proteômica , Venenos de SerpentesRESUMO
Bothrops species trigger an acute inflammatory response in victims, with activated leukocytes releasing several mediators that may contribute to local and systemic effects. The effects of BjcuL, a lectin isolated from B. jararacussu snake venom, on mast cells and vasopermeability were investigated in this study. BjcuL activates mast cells and increases vasopermeability through the involvement of histamine and platelet activating factor, which may play a role in the victims' acute inflammatory reaction.
Assuntos
Bothrops , Animais , Permeabilidade Capilar , Modelos Animais de Doenças , Lectinas , Mastócitos , Venenos de SerpentesRESUMO
Photobiomodulation therapy associated with conventional antivenom treatment has been shown to be effective in reducing the local effects caused by bothropic venoms in preclinical studies. In this study, we analyzed the influence of photobiomodulation using light emitting diode (LED) on the oxidative stress produced by murine macrophages stimulated with Bothrops jararacussu venom and it isolated toxins BthTX-I and BthTX-II. Under LED treatment, we evaluated the activity of the antioxidant enzymes catalase, superoxide dismutase, and peroxidase as well as the release of hydrogen peroxide and the enzyme lactate dehydrogenase. To investigate whether NADPH oxidase complex activation and mitochondrial pathways could contribute to hydrogen peroxide production by macrophages, we tested the effect of two selective inhibitors, apocynin and CCCP3, respectively. Our results showed that LED therapy was able to decrease the production of hydrogen peroxide and the liberation of lactate dehydrogenase, indicating less cell damage. In addition, the antioxidant enzymes catalase, superoxide dismutase, and peroxidase increased in response to LED treatment. The effect of LED treatment on macrophages was inhibited by CCCP3, but not by apocynin. These findings show that LED photobiomodulation treatment protects macrophages, at least in part, by reducing oxidative stress caused B. jararacussu venom and toxins.
Assuntos
Venenos de Crotalídeos , Macrófagos , Animais , Antioxidantes/farmacologia , Bothrops , Catalase , Venenos de Crotalídeos/farmacologia , Peróxido de Hidrogênio/farmacologia , Lactato Desidrogenases , Macrófagos/efeitos dos fármacos , Camundongos , Oxirredução , Estresse Oxidativo , Superóxido DismutaseRESUMO
Phospholipases A2 (PLA2s) are proteins found in snake venoms with hemolytic, anticoagulant, myotoxic, edematogenic, bactericidal and inflammatory actions. In Bothrops jararacussu snake venom were isolated a Lys49-PLA2 (BthTX-I) and an Asp49-PLA2 (BthTX-II) with myotoxic and inflammatory actions. Both PLA2s can activate the NLRP3 inflammasome, an intracytoplasmic platform that recognizes molecules released when tissue is damaged liberating IL-1ß that contributes to the inflammatory response observed in envenoming. The dynamic of action of BthTX-I and BthTX-II in both thioglycollate (TG)-elicited macrophages and C2C12 myoblasts and the involvement of EP1 and EP2 receptors, and PGE2 in NLRP3 inflammasome activation were evaluated. Both toxins induced PGE2 liberation and inflammasome components (NLRP3, Caspase-1, ASC, IL-1ß, and IL18), IL-6, P2X7, COX-1, COX-2, EP2 and EP4 gene expression in TG-elicited macrophages but not in C2C12 myoblasts. EP2 (PF04418948) and EP4 (GW627368X) inhibitors abolished this effect. Both PLA2s also induced NLRP3 inflammasome protein expression that was abolished with the inhibitors used. Immunofluorescence and IL-1ß assays confirmed the NLRP3 activation in TG-elicited macrophages with the participation of both EP2 and EP4 receptors confirming their involvement in this effect. All in all, BthTX-I and BthTX-II activate macrophages and induce the NLRP3 inflammasome complex activation with the participation of the PGE2 via COX pathway and EP2 and EP4, both PGE2 receptors, contributing to the local inflammatory effects observed in envenoming.
Assuntos
Bothrops , Venenos de Crotalídeos , Animais , Camundongos , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Ciclo-Oxigenase 2/genética , Tioglicolatos , Interleucina-18 , Interleucina-6 , Fosfolipases A2 , Venenos de Serpentes , Macrófagos , Caspase 1 , Dinoprostona , Anticoagulantes , PoliésteresRESUMO
Bothropic venoms contains high amount of secreted phospholipases A2 (sPLA2s) that play a significant role in leukocyte activation and inflammation. Monocytes and lymphocytes are highly functional immune system cells that mediate and provide efficient responses during the inflammation. NLRP3 inflammasome is a multiprotein complex found in immune system cells that is triggered by pathogen- and damage-associated molecular patterns, PAMPs and DAMPs, respectively. PLA2s' effect on human peripheral blood mononuclear cells (PBMCs) is still incompletely understood. PBMCs were isolated by density gradient and incubated with RPMI (control), LPS, BthTX-I (PLA2-Lys49) or BthTX-II (PLA2-Asp49) isolated from Bothrops jararacussu venom, to evaluate viability, and the results showed that there was no cell death. RT-qPCR and immunoblot were used to assess the gene and protein expression of NLRP3 components. Results indicated that there was substantial amplification of ASC, Caspase-1, IL-6, and IL-1ß in 1 h and NLRP3 in 2 h. Protein expression was measured, and the results revealed substantial expression of the NLRP3 inflammasome complex after 4 h. IL-1ß and LDH was quantified in the supernatant of the cells. Taken together, the findings demonstrate that BthTX-I and BthTX-II activate the NLRP3 inflammasome complex in human PBMCs and contribute to the inflammatory response seen in envenoming.
Assuntos
Bothrops , Venenos de Crotalídeos , Animais , Bothrops/metabolismo , Venenos de Crotalídeos/farmacologia , Humanos , Inflamassomos/metabolismo , Leucócitos/metabolismo , Leucócitos Mononucleares/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismoRESUMO
In order to address the global antivenom crisis, novel antivenoms need to present high therapeutic efficacy, broad neutralization ability against systemic and local damage, sufficient safety, and cost-effectiveness. Due to biological characteristics of camelid single-domain antibodies (VHH) such as high affinity, their ability to penetrate dense tissues, and facility for genetic manipulation, their application in antivenoms has expanded considerably. VHHs that are active against the metalloprotease BjussuMP-II from the snake Bothrops jararacussu were selected. After isolation of BjussuMP-II, a camelid was immunized with the purified toxin in order to construct the recombinant phage library. Following a round of biopanning, 52% of the selected clones were able to recognize BjussuMP-II in an ELISA assay. After sequencing, seven sequence profiles were identified. One selected clone (VHH61) showed cross-reactivity to B. brazili venom, but did not recognize the Crotalus and Lachesis genera, indicating specificity for the Bothrops genus. Through in vitro tests, the capacity to neutralize the toxicity triggered by BjussuMP-II was observed. Circular dichroism spectroscopy indicated a robust secondary structure for VHH61, and the calculated melting temperature (T M) for the clone was 56.4°C. In silico analysis, through molecular docking of anti-BjussuMP-II VHHs with metalloprotease, revealed their potential interaction with amino acids present in regions critical for the toxin's conformation and stability. The findings suggest that anti-BjussuMP-II VHHs may be beneficial in the development of next-generation antivenoms.
Assuntos
Bothrops , Venenos de Crotalídeos , Anticorpos de Domínio Único , Mordeduras de Serpentes , Animais , Antivenenos/uso terapêutico , Bothrops/metabolismo , Metaloproteases/metabolismo , Simulação de Acoplamento Molecular , Testes de Neutralização , Anticorpos de Domínio Único/farmacologia , Mordeduras de Serpentes/tratamento farmacológicoRESUMO
Convulxin (CVX), a C-type lectin-like protein isolated from the venom of the snake species, Crotalus durissus terrificus, stimulates platelet aggregation by acting as a collagen receptor agonist for glycoprotein VI found in the platelets. The effect of CVX on platelets has been studied, but its effect on human peripheral blood mononuclear cells (PBMCs) remains unclear. Given the significance of PBMCs in inflammation, this study explored the effect of CVX on PBMCs, specifically regarding NLRP3 inflammasome activation by assessing cell viability, ability to induce cell proliferation, reactive oxygen species (ROS) and nitric oxide production, interleukin (IL)-2 and IL-10 secretion, NLRP3 complex activation, and the role of C-type lectin-like receptors (CTLRs) in these. CVX was not toxic to PBMCs at the investigated concentrations and did not increase PBMC growth or IL-2 release; however, CVX induced IL-10 release and ROS generation via monocyte activation. It also activated the NLRP3 complex, resulting in IL-1ß induction. Furthermore, the interaction between CVX and Dectin-2, a CTLR, induced IL-10 production. CVX interaction with CTLR has been demonstrated by laminarin therapy. Because of the involvement of residues near the Dectin-2 carbohydrate-recognition site, the generation of ROS resulted in inflammasome activation and IL-1ß secretion. Overall, this work helps elucidate the function of CVX in immune system cells.
Assuntos
Venenos de Crotalídeos , Crotalus , Animais , Venenos de Crotalídeos/química , Crotalus/metabolismo , Humanos , Inflamassomos , Interleucina-10 , Interleucina-1beta , Lectinas Tipo C/metabolismo , Leucócitos Mononucleares/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Espécies Reativas de OxigênioRESUMO
Photobiomodulation using light-emitting diode (LED) treatment has analgesic and anti-inflammatory effects which can be an effective therapeutic associated with serum therapy for local treatment of snakebites. Here we explored the effects of LED treatment on isolated macrophage under Bothrops jararacussu venom. Results showed that LED induced IL-6 and TNF-α genes down-regulation and, TGF and ARG1 genes up-regulation which indicates a polarization of macrophages to an M2 phenotype contributing to both tissue repair and resolution of inflammation.
Assuntos
Bothrops , Venenos de Crotalídeos , Terapia com Luz de Baixa Intensidade , Animais , Macrófagos , Camundongos , FenótipoRESUMO
Several reports have suggested that photobiomodulation, owing to its analgesic, anti-inflammatory, and healing effects, may be an effective therapeutic option for local effects of snakebites when the availability and accessibility of conventional serum therapy are inefficient and far from medical care centers. Although there have been studies that demonstrate the application of photobiomodulation in the treatment of local adverse events due to snakebites from snakes of the genus Bothrops, its role in the activation of leukocytes, particularly macrophages, has not been evaluated. Here, we assessed the effect of light-emitting diode (LED) treatment on macrophage activation induced by B. jararacussu venom (BjV). LED treatment caused an increase in the viability of macrophages incubated with BjV. This treatment reduced reactive oxygen species (ROS) and nitric oxide (NO) production by macrophages after incubation with BjV. However, LED treatment did not interfere with IL-1ß and IL-10 production by macrophages after incubation with BjV. In conclusion, this study showed that LED treatment has the potential to be used in combination with conventional serum therapy to prevent or minimize the progression of local to severe symptoms after Bothrops envenomation.
Assuntos
Bothrops , Venenos de Crotalídeos/toxicidade , Terapia com Luz de Baixa Intensidade/instrumentação , Macrófagos/efeitos da radiação , Semicondutores , Mordeduras de Serpentes/imunologia , Mordeduras de Serpentes/radioterapia , Animais , Sobrevivência Celular/efeitos dos fármacos , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Espaço Intracelular/efeitos da radiação , Macrófagos/imunologia , Masculino , Camundongos , Óxido Nítrico/biossíntese , Espécies Reativas de Oxigênio/metabolismo , Mordeduras de Serpentes/metabolismo , Mordeduras de Serpentes/patologia , Superóxidos/metabolismoRESUMO
Given the magnitude of the global snakebite crisis, strategies to ensure the quality of antivenom, as well as the availability and sustainability of its supply are under development by several research groups. Recombinant DNA technology has allowed the engineering of monoclonal antibodies and recombinant fragments as alternatives to conventional antivenoms. Besides having higher therapeutic efficacy, with broad neutralization capacity against local and systemic toxicity, novel antivenoms need to be safe and cost-effective. Due to the biological and physical chemical properties of camelid single-domain antibodies, with high volume of distribution to distal tissue, their modular format, and their versatility, their biotechnological application has grown considerably in recent decades. This article presents the most up-to-date developments concerning camelid single-domain-based antibodies against major toxins from snake venoms, the main venomous animals responsible for reported envenoming cases and related human deaths. A brief discussion on the composition, challenges, and perspectives of antivenoms is presented, as well as the road ahead for next-generation antivenoms based on single-domain antibodies.
Assuntos
Anticorpos de Domínio Único/farmacologia , Mordeduras de Serpentes/tratamento farmacológico , Venenos de Serpentes/antagonistas & inibidores , Animais , Camelídeos Americanos , Humanos , Modelos Moleculares , Engenharia de Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacologia , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/genética , Mordeduras de Serpentes/imunologia , Distribuição TecidualRESUMO
Snakebite envenoming is the cause of an ongoing health crisis in several regions of the world, particularly in tropical and neotropical countries. This scenario creates an urgent necessity for new practical solutions to address the limitations of current therapies. The current study investigated the isolation, phytochemical characterization, and myotoxicity inhibition mechanism of gallic acid (GA), a myotoxin inhibitor obtained from Anacardium humile. The identification and isolation of GA was achieved by employing analytical chromatographic separation, which exhibited a compound with retention time and nuclear magnetic resonance spectra compatible with GA's commercial standard and data from the literature. GA alone was able to inhibit the myotoxic activity induced by the crude venom of Bothrops jararacussu and its two main myotoxins, BthTX-I and BthTX-II. Circular dichroism (CD), fluorescence spectroscopy (FS), dynamic light scattering (DLS), and interaction studies by molecular docking suggested that GA forms a complex with BthTX-I and II. Surface plasmon resonance (SPR) kinetics assays showed that GA has a high affinity for BthTX-I with a KD of 9.146 × 10-7 M. Taken together, the two-state reaction mode of GA binding to BthTX-I, and CD, FS and DLS assays, suggest that GA is able to induce oligomerization and secondary structure changes for BthTX-I and -II. GA and other tannins have been shown to be effective inhibitors of snake venoms' toxic effects, and herein we demonstrated GA's ability to bind to and inhibit a snake venom PLA2, thus proposing a new mechanism of PLA2 inhibition, and presenting more evidence of GA's potential as an antivenom compound.
Assuntos
Anacardium/química , Ácido Gálico/farmacologia , Miotoxicidade/tratamento farmacológico , Inibidores de Fosfolipase A2/farmacologia , Fosfolipases A2/metabolismo , Venenos de Serpentes/enzimologia , Animais , Modelos Animais de Doenças , Ácido Gálico/química , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Miotoxicidade/enzimologia , Miotoxicidade/etiologia , Inibidores de Fosfolipase A2/química , Fosfolipases A2/química , Caules de Planta/química , Proteínas de Répteis/química , Proteínas de Répteis/metabolismo , Ressonância de Plasmônio de SuperfícieRESUMO
Polymorphonuclear neutrophils are the most abundant leukocytes in the blood and constitute key components of the innate immunity. Upon infection or tissue damage, neutrophils are recruited to tissues, where they exert a variety of effects, such as microbicidal activity, phagocytosis, degranulation, formation of reactive oxygen species (ROS), release of inflammatory mediators, and formation of neutrophil extracellular traps (NETs). In addition to microbial killing and removal of damaged tissue components, neutrophils play a role in the resolution of inflammation and, in some circumstances, they stimulate chronic inflammation and may contribute to tissue damage. The participation of neutrophils in snakebite envenoming has been explored in the clinical and experimental settings. Clinically, envenomings are associated with increases in the numbers of circulating neutrophils, with a left shift. Experimentally, neutrophils are the first inflammatory cells to reach tissue injected with venoms or tissue-damaging toxins. Venoms and toxins induce several effects on neutrophils in vitro, including chemotaxis, activation, degranulation, synthesis of inflammatory mediators, generation of ROS, and formation of NETs. The role of neutrophils in the pathogenesis of venom-induced tissue damage has been explored, with variable results depending on the venom. In some cases, neutrophils play a key role in muscle regeneration following venom-induced myonecrosis. The processes involved in the recruitment and activation of neutrophils after injection of snake venoms and toxins, and the possible role of these leukocytes in envenomings, are discussed in this review.