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Bothrops moojeni snake venom was fractionated on a CM-Sepharose column which was previously equilibrated with 0.05M ammonium bicarbonate buffer at pH 8.0 and subsequently eluted with an ammonium bicarbonate concentration gradient from 0.05 to 0.5M at constant pH (8.0) and temperature (25°C). The fraction which eluted last (M-VI) showed, after direct lyophilization, a single band by polyacrylamide...
Polyanionic substances are known to inhibit the myotoxic effects of some crotalide snake venoms. Bothropstoxin-I (BthTX-I), a basic Lys49 phospholipase (PLA 2 ) homologue from Bothrops jararacussu venom, besides inducing muscle damage, also promotes the blockade of both directly and indirectly evoked contractions in mouse neuromuscular preparation. In this work, we evaluated the ability of...
Local and systemic skeletal muscle degeneration is a common consequence of envenomations due to snakebites and mass bee attacks. Phospholipases A 2 (PLA 2 ) are important myotoxic components in these venoms, inducing a similar pattern of degenerative events in muscle cells. Myotoxic PLA 2 s bind to acceptors in the plasma membrane, which might be lipids or proteins and which...
Gas gangrene is an acute and devastating infection most frequently caused by Clostridium perfringens and characterized by severe myonecrosis, intravascular leukocyte accumulation, and significant thrombosis. Several lines of evidence indicate that C. perfringens phospholipase C (Cp-PLC), also called alpha-toxin, is the major virulence factor in this disease. This toxin is a Zn 2+ metalloenzyme...
Although much is known about the pathogenesis of crotoxin-induced muscle damage, the initial site and action of the toxin is still not clear. In this study we used an electrochromic fluorescent dye, Di-4-ANEPPS, to measure the changes in membrane potential of isolated murine omohyoid muscle to determine if depolarization could be one of the initial effects of crotoxin. Omohyoid isolates were pre-loaded...
The role of the cytokines TNF-α, IL-1β and IL-6 in the acute local pathological effects induced by Bothrops asper snake venom was assessed in mice. Intramuscular injection of this venom induced increments in IL-1β and IL-6 in muscle, but no elevations of TNF-α were detected. Pentoxifylline (PTX), a methylxanthine derivative that inhibits the synthesis of TNF-α, and antibodies against these three cytokines...
Lys49 phospholipase A 2 homologues are highly myotoxic and cause extensive tissue damage but do not display hydrolytic activity towards natural phospholipids. The binding of heparin, heparin derivatives and polyanionic compounds such as suramin result in partial inhibition (up to 60%) of the myotoxic effects due to a change in the overall charge of the interfacial surface. In vivo experiments...
In a previous study, we showed that the Polybia paulista wasp venom causes strong myonecrosis. This study was undertaken to characterize the myotoxic potency of mastoparan (Polybia-MPII) isolated from venom (0.25μg/μl) and injected in the tibial anterior (TA) muscle (i.m.) of Balb/c mice. The time course of the changes was followed at muscle degenerative (3 and 24h) and regenerative (3, 7, and 21...
The patterns of myotoxicity induced in mice by crotoxin, crotoxin B and a Lys49 phospholipase A 2 (PLA 2 ) homologue were compared. Lys49 PLA 2 -induced local myotoxicity is reflected by creatine kinase (CK) loss in injected gastrocnemius muscle, and by a profile of CK increase in plasma characterized by a rapid increment and drop after intramuscular injection, and by a lack...
Fucoidan, a natural polysaccharide extracted from brown seaweed, inhibits the myotoxic phospholipases A 2 present in the venoms of crotalid snakes. This study evaluated the influence of molecular weight on the ability of fucoidan to prevent muscle necrosis when rapidly administered after injection of a purified myotoxin or crude venom of Bothrops asper, in a mouse model. It was hypothesized...
l-Amino acid oxidases (LAAOs) are widely distributed in snake venoms, which contribute to the toxicity of venoms. However, LAAO from Bungarus fasciatus (B. fasciatus) snake venom has not been isolated previously. In the present study, LAAO from B. fasciatus snake venom was purified by SP-Sepharose HP anion exchange chromatography followed by Heparin–Sepharose FF affinity chromatography procedure and...
Envenomations by Bothrops asper are often associated with complex and severe local pathological manifestations, including edema, blistering, dermonecrosis, myonecrosis and hemorrhage. The pathogenesis of these alterations has been investigated at the experimental level. These effects are mostly the consequence of the direct action of zinc-dependent metalloproteinases (SVMPs) and myotoxic phospholipases...
Ca 2+ ions are essential to myonecrosis, a serious complication of snake envenomation, and heparin seems to counteract this effect. We investigated the effect of local injection of Bothrops jararacussu venom in mouse fast-twitch extensor digitorum longus (EDL) muscle, without or with heparin, on functional/molecular alterations of two central proteins involved in intracellular Ca 2+ ...
Mastoparan firstly described as an inducer of mast cell granules exocytosis has been also related to many essential mechanisms of cell function. In skeletal muscle tissue the best characterization of mastoparan effect was induction of myonecrosis. We examined the ability of mastoparan Polybia-MPII from Polybia paulista wasp venom to induce apoptosis and inflammation in mouse tibial anterior muscle...
We show that ethyl 2-oxo-2H-chromene-3-carboxylate (EOCC), a synthetic coumarin, irreversibly inhibits phospholipase A 2 (sPLA2) from Crotalus durissus ruruima venom (sPLA2r) with an IC 50 of 3.1 ± 0.06 nmol. EOCC strongly decreased the V max and K m , and it virtually abolished the enzyme activity of sPLA2r as well as sPLA2s from other sources. The edema induced by...
Osteopontin (OPN) is a chemotactic, adhesive protein whose receptors include some integrins and matrix proteins known to have role in inflammatory and repair processes. We examined the time course of OPN expression at acute and chronic stages after intramuscular injection of Bothrops lanceolatus venom in rats. Additionally, we examined the expression of CD68 (a marker for phagocytic macrophages) and...
Snake venoms often contain toxins that cause a rapid necrosis of skeletal muscle fibers, referred to as myotoxins. The most common among them are phospholipases A 2 (PLA 2 s), enzymes that have two independent evolutionary origins in snake venoms. Within the group II PLA 2 s found in viperid venoms, a particular subgroup emerged, in which the otherwise conserved Asp49 of their...
Protobothrops flavoviridis serum proteins precipitated with ammonium sulfate were chromatographed on a DEAE-Toyopearl 650M column at pH 7.5 with stepwise increase or with linear gradient of NaCl concentration. Peaks 3 and 4 serum proteins, obtained by linear gradient elution and named Fr de3 and Fr de4 , contained Habu serum factors (HSF) and phospholipase A 2 (PLA 2 ...
Injuries caused by freshwater stingray are common in several regions of South America, although they are underreported. The riverside inhabitants are the main victims in the Amazonian and Midwest regions of South America. The fishermen are injured mainly in the new focus of colonization of the rivers by freshwater stingrays. With the increasing population in these regions, where freshwater stingrays...
During 45 years, the Instituto Clodomiro Picado (ICP, University of Costa Rica) has developed an ambitious scientific, technological, productive, and social program aimed at providing a better understanding of snakes and their venoms, contributing to the development, production and distribution of antivenoms, improving the prevention and management of snakebite envenomings, and strengthening human...
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