, 2006). These accidents frequently result in severe and fatal envenomation. As the antilonomic serum produced by Instituto Butantan in Brazil is the only clinical recourse to revert the dramatic hemorrhagic syndrome in poisoned patients, the limitations in effective treatments, has motivated the increase of knowledge on the biological effects of the whole venom in

experimental models, and also on the molecular mechanisms enrolled in the particular effects of its numerous toxic active principles (for reviews: Berger et al., 2010; Alvarez Flores et al., 2010). The accidents with the caterpillar L. obliqua occurs when the whole animal is crushed by the victim, and the insect’s chitinous bristles are broken and the venomous

hemolymph penetrate in the human skin, reaching blood vessels ( Veiga et al., 2001). The most charactheristic and severe symptoms described for of L. obliqua envenomation are related to hemostatic disturbances, characterized by consumptive p38 protein kinase coagulopathy, a C646 datasheet secondary fibrinolysis ( Kelen et al., 1995), and depending on severity, a compromised renal function ( Burdmann et al., 1996; Fan et al., 1998), which can lead to a poor outcome ( Kowacs et al., 2006; Garcia and Danni-Oliveira, 2007). In vivo and in vitro studies have shown that the L. obliqua venom contains several toxins with pro-coagulant, anticoagulant and antithrombotic activities. Toxic components isolated from L. obliqua’s venom have shown to be responsible for many features of the hemorrhagic syndrome, contributing for the apparently paradoxical actions of the venom on the coagulation system, expressed as simultaneous pro- and anti-clotting effects ( Pinto et al., 2010). In addition to hemorrhagic syndrome, L. obliqua envenomation is characterized by many local effects at (-)-p-Bromotetramisole Oxalate the contact site, such as burning sensation, pain and erythematic signs, which start immediately after contact. Edema formation and leukocyte migration to the site of injury was also described in animal models, characterizing the inflammatory response ( Fan et al., 1998; Correa et al., 2004; Ramos et al.,

2004). Most of inflammatory effects during envenomation rely on the production or release of humoral factors (bradykinin, prostaglandins, histamine), but L. obliqua venomous proteins have been also proposed to induce activation of cellular responses through the up-regulation of several genes that could be involved in the generation and/or amplification of clinical manifestations ( Pinto et al., 2008 and Pinto et al., 2010). Lopap, a prothrombin activator ( Reis et al., 2006) and Losac, a factor X activator ( Chudzinski-Tavassi and Alvarez Flores, 2006), two active proteins isolated from L. obliqua venom, besides their effects on coagulation system, were shown to stimulate endothelial cells, affecting expression of mediators involved in coagulation, fibrinolysis and inflammation ( Carrijo-Carvalho and Chudzinski-Tavassi, 2007).