The seaweed Prasiola crispa (Chlorophyta) neutralizes toxic effects of Bothrops jararacussu snake venom

In Brazil, the snake genus Bothrops has many venomous species with 90 % of cases of accidents. Snake bites by Bothrops jararacussu result in moderate to severe envenoming, characterized by hemorrhage, coagulation disorders, tissue necrosis, and death. Antivenom has been regularly used for more than a century but poorly neutralizes myonecrosis. And, as a consequence, victims may have their affected limbs amputated. Thus, the production of antivenom must be improved as well as alternative treatments investigated. Thus, the ability of four extracts of the green alga Prasiola crispa to neutralize some toxic effects of B. jararacussu venom was tested. P. crispa was collected in Antarctica, then extracted using four solvents, dichloromethane (DCM), ethyl acetate (ETA), n-hexane (HEX), or methanol (MET). The extracts were incubated with B. jararacussu venom, and in vivo (hemorrhagic, lethal, and edematogenic) or in vitro (coagulating and proteolytic) activities were performed. Moreover, B. jararacussu venom was injected into mice before or after the injection of alga extracts. Overall, extracts inhibited all activities. The MET extract inhibited less and HEX, DCM and ETA inhibited more efficiently the activities. These latter extracts fully protected mice from B. jararacussu-induced hemorrhage and delayed death of mice. Edema was partially inhibited (20 %) by all extracts. Neutralization of hemorrhage was also observed when the extracts of P. crispa were administered after or before the venom injection. These results indicate that the extracts of P. crispa have potential to treat or to prevent some toxic effects of B. jararacussu venom, thus aiding in the antivenom therapy.