Through their non-catalityc domains, they interfere with platelet functions and cell adhesion molecules [13]. (EAhy926). Patterns of cytokine and chemokine production by cells exposed Bornyl acetate to the venoms were highly pro-inflammatory. Thus, the results presented here show that venom toxins share important antigenic similarities with South American species toxins, although their proteases have acquired particular substrate specificity. Moreover, the venom displays important cytotoxic and pro-inflammatory action on human cell types such as keratinocytes and endothelial cells, which are important players in the local and systemic Bornyl acetate compartments affected by the envenomation. species account for the majority of venomous ophidian accidents. Envenomation by these snakes has a complex pathophysiology, characterized by prominent local effects (edema, pain, hemorrhage, and necrosis) and systemic effects such as coagulation disturbances, hemorrhage, and renal failure [1,2]. year [3]. venom induces local and systemic effects comparable to bothropic syndrome, but the envenomation is characterized by a predominant prothrombotic profile. Systemic thrombosis development can lead to cerebral, myocardial, or pulmonary infarctions that only rapid treatment with the monospecific commercial antivenom (Bothrofav?, Sanofi-Pasteur, France) can prevent [2,3,4,5]. venom contains five major types of enzymes; zinc-dependent snake venom metalloproteases (SVMPs), snake venom serine proteinases (SVSPs), phospholipases A2 (PLA2), L-amino acid oxidases, and a specific C-type lectin-like molecule [6,7]. SVMPs are particularly abundant in venoms [8,9]. They all share a highly conserved zinc-dependent active site but vary in their non-catalytic domains composition, an important factor in the classification of these toxins [10]. Class I SVMPs (PI-SVMPs) are only composed of the catalytic protease domain. Class II proteins also present a disintegrin domain, whereas class III SVMPs have both a disintegrin-like and a cysteine-rich domain. In addition to the class III structure, CRLF2 some PIII-SVMPs present two C-type lectin-like domains [11,12]. SVMPs induce hemorrhage, myonecrosis, cutaneous lesions and inflammation, and degradation of coagulation factors and extracellular matrix components. Through their non-catalityc domains, they interfere with platelet functions and cell adhesion molecules [13]. SVSPs have a serine residue in their active site. They were shown to disturb haemostasis by affecting platelet function and degrading coagulation cascade components [14]. PLA2s hydrolyse glycerophospholipids in the sn-2 position. Bornyl acetate They are present in enzymatically active or inactive forms in venoms. They display a wide range of biological effects such as neurotoxicity, cardiotoxicity, myotoxicity, hemolysis, and, anti-coagulating, anti-platelet, and edema-forming activities [15]. Three enzymes have already been purified and characterized from venom; a hemorrhagic PI-SVMP, an acidic phospholipase, and a potent fibrinogenolytic enzyme [16,17]. Inflammation induced by venom has been described in rat and mouse models [18,19,20,21]. venom-induced edema is accompanied by local hemorrhage, involves neutrophil infiltration, mast cell degranulation, and the release of arachidonic acid metabolites, bradykinin, histamine, and serotonin in the first hours after inoculation [18,19,21]. Intraperitoneal injection of the venom was followed by intense neutrophil migration, a chemotactic process in which macrophages and lipoxygenase metabolites were involved [20]. Intravenous administration of the specific commercial antivenom shows low efficacy at inhibiting venom-induced rat hind paw edema [19]. The mechanism of thrombosis observed in envenomation by has not yet been elucidated. The venom cleaves purified human fibrinogen but is unable to clot citrated human plasma, and almost normal coagulation profile can be observed in patients developing thrombosis, suggesting that the thrombosis mechanism could involve vascular endothelial cells or platelet activation [2]. It is deprived of defibrinating activity in mice [22,23]. The venom thrombotic syndrome observed in cases of human envenomations is not reproducible in mice [6]. Like the monospecific antivenom raised against venom, the therapeutic Costa Rican polyvalent antivenom (Clodomiro Picado Institute, Costa Rica) was shown to recognize venom toxic compounds in vitro and to be fully effective in mice in neutralizing the lethal, hemorrhagic, edema-forming, myotoxic, and indirect hemolytic activities of the venom [6,22]. The commercial Brazilian bothropic antivenom is obtained from the hyperimmune sera of horses immunized with a pool of five Brazilian.

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