25 resultados para wasp venom mastoparan


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Context: Sapindus saponaria L. (Sapindaceae) bark, root, and fruits are used as sedatives and to treat gastric ulcer and also demonstrate diuretic and expectorant effects. Objective: The anti-snake venom properties of callus of S. saponaria are investigated here for the first time. Materials and methods: In vitro cultivated callus of Sapindus saponaria were lyophilized, and the extracts were prepared with different solvents, before submitting to phytochemical studies and evaluation of the anti-ophidian activity. Crude extracts were fractionated by liquid-liquid partition and the fractions were monitored by thin layer chromatography (TLC). Subsequently, anti-ophidian activities were analyzed toward Bothrops jararacussu Lacerda (Viperidae), B. moojeni Hoge (Viperidae), B. alternates Dumeril (Viperidea) and Crotalus durissus terrificus Lineu (Viperidae) venoms and isolated myotoxins and phospholipase A(2) (PLA(2)). Results: Fractions A1, A2 and the extract in MeOH:H2O (9:1) significantly inhibited the toxic and pharmacological activities induced by snake venoms and toxins, when compared to other extracts and fractions. The lethal, clotting, phospholipase, edema-inducing, hemorrhagic and myotoxic activities were partially inhibited by the different extracts and fractions. TLC profiles of the crude extracts (B and C) and fractions (A1 and A2) showed beta-sitosterol and stigmasterol as their main compounds. Stigmasterol exhibited inhibitory effects on enzymatic and myotoxic activities of PLA(2). Discussion and conclusion: Sapindus saponaria extracts and fractions presented anti-ophidian activity and could be used as an adjuvant to serum therapy or for its supplementation, and in addition, as a rich source of potential inhibitors of enzymes involved in several pathophysiological human and animal diseases.

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In Brazil, the species Tityus serrulatus is responsible for the most severe cases of scorpion envenomation. There is currently a need for new scorpion anti-venoms that are more effective and less harmful. This study attempted to produce human monoclonal antibodies capable of inhibiting the activity of T. serrulatus venom (TsV), using the Griffin.1 library of human single-chain fragment-variable (scFv) phage antibodies. Four rounds of phage antibody selection were performed, and the round with the highest phage antibody titer was chosen for the production of monoclonal phage antibodies and for further analysis. The scFv 2A, designated serrumab, was selected for the production and purification of soluble antibody fragments. In a murine peritoneal macrophage cell line (J774.1), in vitro assays of the cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, and IL-10 were performed. In male BALB/c mice, in vivo assays of plasma urea, creatinine, aspartate transaminase, and glucose were performed, as well as of neutrophil recruitment and leukocyte counts. It was found that serrumab inhibited the TsV-induced increases in the production of IL-6, TNF alpha, and IL-10 in J774.1 cells. The in vivo inhibition assay showed that serrumab also prevented TsV-induced increases in the plasma levels of urea, creatinine, aspartate transaminase, and glucose, as well as preventing the TsV-induced increase in neutrophil recruitment. The results indicate that the human monoclonal antibody serrumab is a candidate for inclusion in a mixture of specific antibodies to the various toxins present in TsV. Therefore, serrumab shows promise for use in the production of new anti-venom.

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We show that BJcuL, a lectin purified from Bothrops jararacussu venom, exerts cytotoxic effects to gastric carcinoma cells MKN45 and AGS. This effect was due to the direct interaction with specific glycans on the cells surface and was observed by cell viability decrease, disorganization of actin filaments and apoptosis. In addition, BJcuL was able to reduce tumor cell adhesion to matrigel, what was inhibited by specific carbohydrate or partially inhibited when cells were pre-incubated with matrigel. Our results suggest that BJcuL was able to promote apoptosis in both tumor cells lines and therefore has a prospect for potential use in cancer therapy. (C) 2011 Elsevier Ltd. All rights reserved.

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This study reports the isolation and biochemical characterization of two different serine proteases from Bothrops pirajai snake venom, thus providing a comparative analysis of the enzymes. The isolation process consisted of three consecutive chromatographic steps (Sephacryl S-200, Benzamidine Sepharose and C2/C18), resulting in two serine proteases, named BpirSP27 and BpirSP41 after their molecular masses by mass spectrometry (27,121 and 40,639 Da, respectively). Estimation by SDS-PAGE under denaturing conditions showed that, when deglycosylated with PNGase F, BpirSP27 and BpirSP41 had their molecular masses reduced by approximately 15 and 42%, respectively. Both are acidic enzymes, with pI of approximately 4.7 for BpirSP27 and 3.7 for BpirSP41, and their N-terminal amino acid sequences showed 57% identity to each other, with high similarity to the sequences of other snake venom serine proteases (SVSPs). The enzymes showed different actions on bovine fibrinogen, with BpirSP27 acting preferentially on the B beta chain and BpirSP41 on both A alpha and B beta chains. The two serine proteases were also able to degrade fibrin and blood clots in vitro depending on the doses and incubation periods, with higher results for BpirSP41. Both enzymes coagulated the human plasma in a dose-dependent manner, and BpirSP41 showed a higher coagulant potential, with minimum coagulant dose (MCD) of similar to 3.5 mu g versus 20 mu g for BpirSP27. The enzymes were capable of hydrolyzing different chromogenic substrates, including S-2238 for thrombin-like enzymes, but only BpirSP27 acted on the substrate S-2251 for plasmin. They also showed high stability against variations of temperature and pH, but their activities were significantly reduced after preincubation with Cu2+ ion and specific serine protease inhibitors. In addition. BpirSP27 induced aggregation of washed platelets to a greater extent than BpirSP41. The results showed significant structural and functional differences between B. pirajai serine proteases, providing interesting insights into the structure-function relationship of SVSPs. (C) 2012 Elsevier Masson SAS. All rights reserved.

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Bee venom (BV) allergy is potentially dangerous for allergic individuals because a single bee sting may induce an anaphylactic reaction, eventually leading to death. Currently, venom immunotherapy (VIT) is the only treatment with long-lasting effect for this kind of allergy and its efficiency has been recognized worldwide. This therapy consists of subcutaneous injections of gradually increasing doses of the allergen. This causes patient lack of compliance due to a long time of treatment with a total of 30-80 injections administered over years. In this article we deal with the characterization of different MS-PLGA formulations containing BV proteins for VIT. The PLGA microspheres containing BV represent a strategy to replace the multiple injections, because they can control the solute release. Physical and biochemical methods were used to analyze and characterize their preparation. Microspheres with encapsulation efficiencies of 49-75% were obtained with a BV triphasic release profile. Among them, the MS-PLGA 34 kDa-COOH showed to be best for VIT because they presented a low initial burst (20%) and a slow BV release during lag phase. Furthermore, few conformational changes were observed in the released BV. Above all, the BV remained immunologically recognizable, which means that they could continuously stimulate the immune system. Those microspheres containing BV could replace sequential injections of traditional VIT with the remarkable advantage of reduced number of injections. (C) 2011 Elsevier B.V. All rights reserved.

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A hyaluronidase (CdtHya1) from Crotalus durissus terrificus snake venom (CdtV) was isolated and showed to exhibit a high activity on hyaluronan cleavage. However, surveys on this enzyme are still limited. This study aimed at its isolation, functional/structural characterization and the evaluation of its effect on the spreading of crotoxin and phospholipase A(2) (PLA(2)). The enzyme was purified through cation exchange, gel filtration and hydrophobic chromatography. After that, it was submitted to a reverse-phase fast protein liquid chromatography (RP-FPLC) and Edman degradation sequencing, which showed the first N-terminal 44 amino acid residues whose sequence evidenced identity with other snake venom hyaluronidases. CdtHya1 is a monomeric glycoprotein of 64.5 kDa estimated by SDS-PAGE under reducing conditions. It exhibited maximum activity in the presence of 0.2 M NaCl, at 37 degrees C, pH 5.5 and a specificity to hyaluronan higher than that to chondroitin-4-sulphate, chondroitin-6-sulphate or dermatan. Divalent cations (Ca2+ and Mg2+) and 1 M NaCl significantly reduced the enzyme activity. The specific activity of CdtHya1 was 5066 turbidity reducing units (TRU)/mg, against 145 TRU/mg for the soluble venom, representing a 34.9-fold purification. The pure enzyme increased the diffusion of crotoxin and PLA (2) through mice tissues. CdtHya1 (32 TRU/40 mu L) potentiated crotoxin action, as evidenced by mice death, and it decreased the oedema caused by subplantar injections of buffer, crotoxin or PLA(2), thus evidencing the relevance of hyaluronidase in the crotalic envenoming. This work yielded a highly active antiedematogenic hyaluronidase from CdtV, the first one isolated from rattlesnake venoms. (C) 2012 Elsevier Masson SAS. All rights reserved.

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Two myotoxic and noncatalytic Lys49-phospholipases A2 (braziliantoxin-II and MT-II) and a myotoxic and catalytic phospholipase A2 (braziliantoxin-III) from the venom of the Amazonian snake Bothrops brazili were crystallized. The crystals diffracted to resolutions in the range 2.562.05 angstrom and belonged to space groups P3121 (braziliantoxin-II), P6522 (braziliantoxin-III) and P21 (MT-II). The structures were solved by molecular-replacement techniques. Both of the Lys49-phospholipases A2 (braziliantoxin-II and MT-II) contained a dimer in the asymmetric unit, while the Asp49-phospholipase A2 braziliantoxin-III contained a monomer in its asymmetric unit. Analysis of the quaternary assemblies of the braziliantoxin-II and MT-II structures using the PISA program indicated that both models have a dimeric conformation in solution. The same analysis of the braziliantoxin-III structure indicated that this protein does not dimerize in solution and probably acts as a monomer in vivo, similar to other snake-venom Asp49-phospholipases A2.

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Abstract Background Swarm-founding epiponine wasps are an intriguing group of social insects in which colonies are polygynic (several queens share reproduction) and differentiation between castes is often not obvious. However, caste differences in some may be more pronounced in later phases of the colony cycle. Results Using morphometric analyses and multivariate statistics, it was found that caste differences in Metapolybia docilis are slight but more distinct in latter stages of the colony cycle. Conclusions Because differences in body parts are so slight, it is proposed that such variation may be due to differential growth rates of body parts rather than to queens being larger in size, similar to other previously observed epiponines.

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Background: Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation. Methodology/Principal Findings: Female Lewis rats (7 weeks old) were subjected to VRA and root replantation. The animals were divided into two groups: 1) avulsion only and 2) replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera). Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group. Conclusions/Significance: In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the astroglial reaction and increased mRNA levels to neurotrophins and anti-inflammatory cytokines that may in turn, contribute to improving recovery of motor function.

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Surprisingly little is known of the toxic arsenal of cnidarian nematocysts compared to other venomous animals. Here we investigate the toxins of nematocysts isolated from the jellyfish Olindias sambaquiensis. A total of 29 unique ms/ms events were annotated as potential toxins homologous to the toxic proteins from diverse animal phyla, including conesnails, snakes, spiders, scorpions, wasp, bee, parasitic worm and other Cnidaria. Biological activities of these potential toxins include cytolysins, neurotoxins, phospholipases and toxic peptidases. The presence of several toxic enzymes is intriguing, such as sphingomyelin phosphodiesterase B (SMase B) that has only been described in certain spider venoms, and a prepro-haystatin P-IIId snake venom metalloproteinase (SVMP) that activates coagulation factor X, which is very rare even in snake venoms. Our annotation reveals sequence orthologs to many representatives of the most important superfamilies of peptide venoms suggesting that their origins in higher organisms arise from deep eumetazoan innovations. Accordingly, cnidarian venoms may possess unique biological properties that might generate new leads in the discovery of novel pharmacologically active drugs.