This was in contrast to Ts6, which inhibited TNF-α release at 25 and 50 μg/mL. When cells were pre-stimulated with LPS, TsV at all concentrations (Fig. 3B) and Ts1 (Fig. 3D) or Ts6 (Fig. 3H) at 100 μg/mL were also able to induce TNF-α release compared to LPS alone. On the other hand, Ts2 inhibited the release of TNF-α at all concentrations in the presence of LPS (Fig. 3F). Fig. 4 shows the IL-6 release induced by venom and its toxins. Compared to RPMI-c alone, GW-572016 nmr TsV (Fig. 4A) or Ts1 (Fig. 4C) at all concentrations

or Ts6 at 50 or 100 μg/mL (Fig. 4G) stimulated the cells to release of IL-6. In the presence of LPS, more IL-6 was released after addition of TsV (at all concentrations) or Ts1 or Ts6 (100 μg/mL) compared to LPS alone. Likewise, it should be noted that Ts2 (from 25 to 100 μg/mL) induced a marked decrease in IL-6 release compared to LPS alone (P < 0.05). This result suggests an anti-inflammatory Pictilisib manufacturer activity of Ts2 at these concentrations. The same behavior was not observed for IL-1β, which was not detected by the method used (data not shown). The release of IL-10, an immunoregulatory cytokine is shown in

Fig. 5. Only Ts2 (100 μg/mL), in the absence of LPS, promoted an increase in IL-10 release compared to RPMI-c (Fig. 5A). Cells pre-stimulated with LPS did not release IL-10 when stimulated with any concentration of Ts2 (Fig. 5B). TsV, Ts1 and Ts6 also did not induce IL-10 production (data not shown). Taken together, these results indicate an anti-inflammatory activity for Ts2. Scorpion envenomation is an important public health problem (Chippauxa and Goyffonb, 2008); therefore, we analyzed the macrophage cytokine production and NO release induced

by scorpion venom and its constituent PLEK2 toxins. Following envenomation, the released cytokines may contribute to inflammation and the activation of macrophages, as well as the induction of the immune response (Commins et al., 2010). In cases of severe envenomation by T. serrulatus, a systemic inflammatory response-like syndrome is triggered, with the release of inflammatory cytokines, that contributes to immunological imbalance, multiple organ dysfunction and death ( Magalhães et al., 1999 and Petricevich, 2010). Here, we showed that TsV, Ts1 and Ts6 stimulated the release of NO, IL-6 and TNF-α by J774.1 cells and that Ts2, in the presence of LPS, inhibited the release of these inflammatory mediators. Further, in the absence of LPS, Ts2 stimulated increased IL-10 production. First, it was important to determine if venom and its component toxins constituted a cytotoxic stimulus per se. Low cytotoxicity was only observed using 100 μg/mL of Ts2; this phenomenon does not interfere with macrophage activation and production of mediators because similar results were observed at 25 and 50 μg/mL.