Treatment Of Snakebite Envenoming Research Articles

Triterpenoid saponins, new metalloprotease snake venom inhibitors isolated from Pentaclethra macroloba

We report here the antiproteolytic and antihemorrhagic properties of triterpenoid saponin inhibitors, named macrolobin-A and B, from Pentaclethra macroloba, against Bothrops snake venoms. The inhibitors were able to neutralize the hemorrhagic, fibrin(ogen)olytic, and proteolytic activities of class P-I and P-III metalloproteases isolated from B. neuwiedi and B. jararacussu venoms. Clotting and fibrinogenolytic activities induced by snake venoms and isolated thrombin-like enzymes were partially inhibited. Furthermore, the potential use of these inhibitors to complement antivenom therapy as an alternative treatment and/or used as molecular models for development of new therapeutical agents in the treatment of snake bite envenomations needs to be evaluated in future studies.

Anti-human erythrocyte antibodies in horse-derived antivenoms used in the treatment of snakebite envenomations

This work examined the presence of antibodies reacting with human erythrocytes in horse-derived antivenoms used in the treatment of snakebite envenomations, and assessed the efficacy of various fractionation protocols in the elimination of agglutinating antibodies. A number of antivenoms produced by various fractionation protocols were tested for direct agglutination of human erythrocytes. Reactions were observed visually and microscopically, and an indirect anti-equine globulin test was also used. In addition, rabbits and mice were injected intravenously with antivenoms to observe possible intravascular hemolysis and erythrocyte sequestration. All tested antivenoms agglutinated human erythrocytes, albeit to different extent, and also gave a positive anti-globulin test. Agglutination was due to IgG(T) subclass of antibodies. Pepsin digestion of horse IgG, to obtain F(ab′) 2 fragments, reduced the direct agglutination, but not the indirect anti-globulin test. Ion-exchange chromatography of IgG in a strongly basic quaternary ammonium cellulose membrane abrogated direct agglutination and reduced the indirect anti-globulin test. Binding of antivenom antibodies to erythrocytes in vivo was demonstrated in rabbits, although there was no evidence of intravascular hemolysis or erythrocyte sequestration in rabbits and mice. It is concluded that anti-human erythrocyte antibodies are present in horse-derived antivenoms, and that fractionation of horse plasma by pepsin digestion, and especially by anion-exchange chromatography, reduces the titer of these antibodies. Our in vivo experimental results do not support a role for these antibodies in early adverse reactions occurring after antivenom administration.

The use of therapeutic plasmapheresis in the treatment of poisoned and snake bite victims: An academic emergency department's experiences

The objective of this study is to describe the clinical status, procedural interventions, and outcomes of critically ill patients with poisoning and snake bite injuries presenting to a tertiary-care emergency department for treatment with therapeutic plasmapheresis. Records of 20 patients who presented to our academic emergency department over a 2-year period and who underwent plasmapheresis for poisoning or snake bite were retrospectively reviewed. Plasmapheresis was performed using centrifugation technology via an intravenous antecubital venous or subclavian vein catheter access. Human albumin or fresh frozen plasma were used as replacement fluids. Data extracted from the patient record included demographic data, clinical status, and outcome measures. Sixteen patients underwent plasmapheresis because of toxicity from snake bite. Three patients were treated for drug poisoning (phenytoin, theophylline, bipyridene HCl) and one patient for mushroom poisoning. Haematologic parameters such as platelet count, PT, and INR resolved rapidly in victims of snake bite injuries after treatment with plasmapheresis. Loss of limbs did not occur in these cases. Seven patients required admission to the intensive care unit. One patient with mushroom poisoning died. Mean length of hospital stay was 14.3 days (range 3-28 days) for all cases. Plasmapheresis was a clinically effective and safe approach in the treatment of snake bite envenomation and other drug poisoning victims especially in the management of hematologic problems and in limb preservation/salvage strategies. In addition to established conventional therapies, emergency physicians should consider plasmapheresis among the therapeutic options in treatment strategies for selected toxicologic emergencies.

Neo-clerodane diterpenoid, a new metalloprotease snake venom inhibitor from Baccharis trimera (Asteraceae): anti-proteolytic and anti-hemorrhagic properties

Many plants are used in traditional medicine as active agents against various effects induced by snakebite. Few attempts have been made however to identify the nature of plant natural products with anti-ophidian properties. Baccharis trimera (Less) DC (Asteraceae), known in Brazil as carqueja, has been popularly used to treat liver diseases, rheumatism, diabetes, as well as digestive, hepatic and renal disorders. The active component was identified as 7α-hydroxy-3,13-clerodadiene-16,15:18,19-diolide, C 20H 28O 5, (clerodane diterpenoid, Bt-CD). We report now the anti-proteolytic and anti-hemorrhagic properties against snake venoms of a Bt-CD inhibitor from B. trimera. Bt-CD exhibited full inhibition of hemorrhage and proteolytic activity caused by Bothrops snake venoms. The inhibitor was able to neutralize the hemorrhagic, fibrinogenolytic and caseinolytic activities of class P-I and III metalloproteases isolated from B. neuwiedi and B. jararacussu venoms. No inhibition of the coagulant activity was observed. Bt-CD also partially inhibited the edema induced by other crude venoms, metalloproteases, basic and acidic phospholipases A 2. To further elucidate the inhibitory specificity of Bt-CD against metalloproteases isolated from snake venoms, a deeper understanding of its structure and function is necessary. Furthermore, the potential use of these inhibitors to complement anti-venom as an alternative treatment of snakebite envenomations needs to be evaluated in future studies.

Evaluation of the neutralizing ability of antivenoms for the treatment of snakebite envenomations in central America

Evaluation of the neutralizing ability of antivenoms for the treatment of snakebite envenomations in central America

Evaluation of trypsin treatment for snakebite envenomation

Evaluation of trypsin treatment for snakebite envenomation