Neuroprotection Effects Of The Extract And Srtx1 Fraction From Scaptocosa Raptoria Spider Venom (Lycosidae; Araneae).

Alessandra Mussi Ribeiro, Márcia Renata Mortari, Andrea Baldochi Pizzo, and Wagner Ferreira dos Santos.

Laboratory of Neurobiology and Venoms, Department of Biology, FFCLRP-University of São Paulo, Brazil. 

In this study we chose to interfere with hippocampal function by inducing epileptic seizures with pilocarpine, because these seizures exclusively damage the hippocampal neurons. We investigated the behavioral effects of the crude denatured venom and fraction from the spider S. raptoria in the Morris water maze task. Wistar rats were cannulated in the dorsal hippocampus by means of stereotaxic surgery (AP: -3,8 mm; ML: -1,6 mm; DV: -2,2 mm). The experimental groups were injected with pilocarpine (2,4 mg/ml), and the control group was injected with saline (0,9%; 1 ml). After 180 min of status epilepticus all animals were injected thionembutal (40 mg/kg). After 60 min animals were injected with boiled denatured S. raptoria crude venom (AbSr) or SrTx1.3 (obtained by HPLC). After one week rats were submitted to daily sessions of six trials per day for 4 days to find the submerged platform that was located in the center of a quadrant of the tank and remained there throughout the training. We observed that all animals of the saline, AbTx and SrTx1.3 groups were able to swim in a normal way during all trials. On each trial, the rat was placed in the water, facing the edge of the tank, in one of the four standard start locations. The order of the start locations varied in a quasi-random sequence. Latency to find the platform (escape latency) was measured in each trial. Once the rat located the platform, it was allowed to remain there for 30 s. If the rat could not find the platform within 90 s, it was guided to it and allowed to stand there for 30 s. After each trial, the rats were removed, dried with a towel and put back in their home cages. Animals injected only with pilocarpine were not able to find the platform. It can be seen that AbSr and SrTx1.3 groups had better water maze acquisition performance, i.e., decreased the latency [F (6, 37) = 13.72; p < 0,001], to find the platform. On the probe trial, with platform removed, AbTx and SrTx1.3 groups were able to remember the location of the platform, spending the same period of time in the training quadrant as the normal non-injected individuals [F (3, 111) = 43.07; p < 0.001]. These results showed the animals of the groups AbTx and SrTx1.3 preferentially remained in the training quadrant. The venom described in this work seems a potential source for new neuroprotector drugs.

Financial Support: CNPq.

Correspondence to: mmortari@usp.br