Toxic activities of Brazilian centipede venoms.
ABSTRACT Centipedes have a venom gland connected to a pair of forceps, which are used to arrest preys. Human victims bitten by centipedes usually manifest burning pain, paresthesia and edema, which may develop into superficial necrosis. The aim of this work was to characterize and compare toxic activities found in venoms of three species of Brazilian centipedes-Otostigmus pradoi, Cryptops iheringi and Scolopendra viridicornis. By SDS-PAGE (4-20%), important differences were noticed among venoms (between 7 and 205kDa). Few bands showed feeble caseinolytic, fibrinogenolytic and gelatinolytic activities by zymography, but strong hyaluronidase activity was observed in S. viridicornis and O. pradoi venoms. In addition, such activities could be inhibited by o-phenanthroline, indicating that these enzymes are metalloproteinases. All venoms induced nociception, edema and myotoxicity in mice, but only S. viridicornis induced mild hemorrhagic activity. No coagulant activity was detected in centipede venoms. Low phospholipase A(2) activity was observed exclusively in S. viridicornis and O. pradoi venoms, but these venoms had intense direct hemolytic activity on human erythrocytes. Cross-reactivity among venoms was observed using species-specific sera raised in rabbits. Differences were noticed among centipede venoms, but S. viridicornis is indeed the most toxic venom and thereby it could induce a more severe envenomation.