Atividade neuroprotetora do extrato etanólico de aristolochia cymbifera sobre o sistema nervoso central e periférico de vertebrados

Abstract

Brazil detains the richest biodiverity in the world, with several species of plant presenting medicinal properties. Brazil has the highest rate of accidents by venomous animals. And the main treatment for these accidents is the use of antiofidic serum, wich many times do not prevent peripheral and central neurotoxic effects. Among the several medicinal plants known for their activity on the central nervous system is Aristolochia cymbifera, a plant popularly known as a neuroprotective agent, because it presents terpenoids, lignoids, flavonoids in its composition, already known for such an effect. In this way, in this work we propose to prove the neuroprotective activity of the ethanolic extract of Aristolochia cymbifera against venom of the Brazilian rattlesnake on the central nervous system by means of hippocampal cell viability assays of mice using the MTT method, which consists in the reduction of salt MTT to the formazan salt, and long-duration potentiation (LTP) assays were also performed using rat hippocampus, analyzing field post-synaptic excitatory potentials. And to evaluate the neuroprotection on the peripheral nervous system was used to neuromuscular junction preparations, using biventer cervicis of chicks. Our results demonstrated that neuroprotection occurred in the central nervous system. When the extract was incubated with the treatment as opposed to the venom, an increase in the cellular viability was observed, as the concentrations of ethanolic extract of Aristolochia cymbifera increased, 30% ± 1, 55% ± 1 and 75% ± 2 for the concentrations of 200, 400 and 800 μg / ml, respectively. In the LTP assays, without the addition of the extract, the amplitude of the excitatory potentials was 190.6 ± 10mV. The infusion of EAAC (200μg / ml) for 5 minutes on the hippocampal slices reduced to 140 ± 0.7mV. However, in the neuromuscular junction preparations the ethanolic extract did not present neuroprotection to the peripheral nervous system. Based on these results we can infer that the ethanolic extract of Aristolochia cymbifera was beneficial to the central nervous system and that probably due considerably concentration of the venom of rattlesnake can not be observed the peripheral neuroprotection.