Use of freeze-dried trivalent antivenom to neutralize the toxic activities of Bothrops atrox snake venoms from the Amazon

Ability of brazilian Bothrops-Lachesis-Crotalus antivenom in neutralizing some biological activities of Crotalus durissus ruruima rattlesnake venom

We evaluated the efficacy of freeze-dried Bothrops-Lachesis-Crotalus antivenom and liquid Crotalus antivenoms to neutralize Crotalus durissus ruruima (Cdr) venom (Roraima, Brazil) comparing with C. d. terrificus (Cdt) venom. Lethal and phospholipase A2 activities were similar between both spp. Crotamine was negative and individual Cdr venoms induced hemorrhage in mice. It was lower coagulant than Cdt venom. Only Bothrops-Lachesis-Crotalus antivenom neutralized all biological activities evaluated, suggesting that it could be used in snakebites in this region.

A First Look at the Inhibitory Potential of Urospatha sagittifolia (Araceae) Ethanolic Extract for Bothrops atrox Snakebite Envenomation

Bothrops atrox snakebites are a relevant problem in the Amazon basin. In this biodiverse region, the ethnomedicinal approach plays an important role as an alternative to antivenom therapy. Urospatha sagittifolia (Araceae) is a plant used for this purpose; however, its neutralizing properties have not been scientifically accessed. To fill this gap, we investigated the ability of U. sagittifolia to modulate the catalytic activity of Bothrops atrox venom, and their toxic consequences, such as local damage and lethality. The venom profile of B. atrox was assessed by chromatography and electrophoresis. Inhibition of the three main enzymatic and medically important toxins from the venom was evaluated using synthetic substrates and quantified by chromogenic activity assays. Additionally, the neutralization of lethality, hemorrhage and edema were investigated by in vivo assays. The possible interactions between venom proteins and plant molecules were visualized by polyacrylamide gel electrophoresis. Finally, the phytochemical constituents present in the ethanolic extract were determined by qualitative and quantitative analyses. The ethanolic extract reduced the activity of the three main enzymes of venom target, achieving ranges from 19% to 81% of inhibition. Our in vivo venom neuralizations assays showed a significant inhibition of edema (38.72%) and hemorrhage (42.90%). Additionally, lethality was remarkably counteracted. The highest extract ratio evaluated had a 75% survival rate. Our data support the biomedical value of U. sagittifolia as a source of natural enzyme inhibitors able to neutralize catalytically active B. atrox venom toxins and their toxic effects.