Caracterização da resposta inflamatória local induzida pela peçonha do peixe-escorpião Scorpaena plumieri

Abstract

Envenomation with Scorpaena plumieri fish venom causes immediate, local, and intense pain, and tissue edema in humans. The aim of the present study was to characterize experimentally the local acute inflammatory response induced by S. plumieri venom (SpV). Mouse paw edema bioassays have showed that SpV (7.5 - 100 µg of protein) induce intense local edema and nociception. The edema intensity and its persistence were dose-dependent. It was also demonstrated that previous administration of serine-protease inhibitor (aprotinin) or bradykinin B2 receptor antagonist (HOE-140) significantly reduces the edematogenic response to venom. These results demonstrate a direct involvement of the Kallikrein-Kinin System in the edema formation. However, the pre-treatment with other anti-inflammatory drugs (antihistamine and inhibitor of COX-2) had less effect on this response. Elevated levels of proinflammatory mediators (cytokines TNF and IL-6 and the chemokine MCP-1) were detected in supernatants of paw tissue extracts by flow cytometric analyses 2h after SpV (15 µg of protein) injection. This proinflammatory mediators release could be associated with histopathological changes observed into paw tissue, characterized by cellular infiltration, mainly neutrophils (6h) followed later by mononuclear cell recruitment (12h after injection). It was also observed edema at strong dermis of the tissue injected. Thus, kinins, in concert with cytokines, may regulate leucocytes interstitial accumulation and trafficking to the inflammatory site. Partial purification of a proteic proinflammatory fraction, which reproduced the edematogenic response induced by crude venom, was achieved by gel filtration and anion exchange chromatographies. In addition also was demonstrated that stonefish antivenom (SFAV) is able to neutralize in vivo nociceptive and edematogenic activities of the venom of S. plumieri. Western immunoblotting analysis confirmed the cross reactivity, since SpV proteins with MW in the range of ~ 98 kDa were recognized by SFAV. These experiments suggest that the SpV compound responsible for the inflammatory effects possesses similar antigenic properties to those found in stonefish venom. In conclusion, this work described for the first time the pattern of local inflammatory reaction elicited by S. plumieri venom. It was also reported structural similarities between venom proteins from Indo-Pacific (stonefish) and Atlantic Ocean fish (scorpionfish).