Neuropharmacological profile of FRPB11, purified from the venom of the social spider Parawixia bistriata (Araneae, Araneidae), in Wistar rats

Abstract

Conventional anticonvulsant drugs induce untoward side effects that limit the chronic treatment of some brain pathologies. That is the main reason for the continuous need of novel neuroactive compounds as those found in arthropod venoms. These molecules interact with a wide range of biological systems, including the central nervous system. In the light of these facts, our laboratory has isolated two compounds from the venom of the spider Parawixia bistriata, which act over transporters for GABA and glutamate; PbTx1.2.3 (Parawixin I) and FrPbAII. Parawixin I exerts its actions by inhibiting EAAT2 expressed in COS cells, and it is neuroprotective in a model of retina lesion. FrPbAII, in turn inhibits GABA and Glycine uptakes in cerebrocortical synatossomes, but does not interfere with receptor binding and synaptic enzymes. Both compounds have remarkable pharmacological potential, since they both act over transporter and thus, they may function in physiological concentrations of released neurotransmitter. This approach is thought to induce milder side-effects. Although encouraging, the results obtained from the studies using low molecular weight compounds from P. bistriata spider venom are still in the beginning. There are many other interesting compounds in this venom in the phase of structural elucidation, whose actions should be investigated. Therefore, the main goal of the present study is to evaluate the neuropharmacological profile of fraction FrPb11, recently isolated in our laboratory, using Wistar rats submitted to consolidated models of anticonvulsant screening.