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Poster 258. Congresso da Sociedade Brasileira de Toxinologia, 8., Symposium of the Pan American Section of the International Society on Toxinology, 8., 2004, Angra dos Reis, Brasil. Abstracts... J. Venom. Anim. Toxins incl.Trop. Dis., 2004, 10, 3, p.617. |
Anticonvulsant and behavioral effects of the denatured venom the socialwasp Polybia occidentalis on Chemically Induced Seizures
Márcia Renata Mortari, Alexandra Olimpo Siqueira Cunha, Luciana de Oliveira, Wagner Ferreira dos Santos
Neurobiology and Venoms Laboratory – Department of Biology - FFCLRP/USP
The objectives of this work were to evaluate the anticonvulsant and behavioral effects due to i.c.v. injections of the denatured venom of the social wasp P. occidentalis. in rats. Venom sacs were dissecated from the wasps crushed and centrifuged at 5000 g for 10 min, the supernatant was collected, added acetonitrile (1:1), boiled for 10 min, lyophilized and weighted. There were made progressive dilutions in saline solution (0,9%) to perform the denatured venom (PoDv) bioassays. Bioassays were conducted using Male Wistar rats (200-250g), which were anaesthetized, placed in a stereotaxic frame where stainless steel guide cannulas were implanted into the lateral ventricle. The animals were allowed to recover 5-7 days from surgery, after which they were injected with PoDv and convulsant agents in a volume of 3 ml/min. Diazepam was used as positive control and saline alone was used before the convulsant drugs. Behaviors were grouped in four categories (inactivity, grooming, rearing and exploratory). It was also determined the spontaneous locomotor activity of the animals by counting the line crossings along 4 time windows (0-5; 5-10; 10-15 and 15-20 min) in the open field. Seizures were evaluated by Racine (1972) score modified by Pinel and Rovner (1978). The duration of behaviors were compared with the control group (saline) by ANOVA followed by Tukey test (n = 6-8/dose). Anticonvulsant activity was measured as the frequency of protected animals and it was analyzed using the chi-square test (p<0.05 and p<0.001). When injected via i.c.v., PoDv inhibited the locomotor activity and decreased the exploratory, grooming and rearing. The denatured venom demonstrated to be anticonvulsive against acute chemical induced seizures as PoDv blocked seizures induced by the i.c.v. injection of bicuculline and picrotoxina (both, CD97).This anticonvulsant effect was dose dependent.
These findings indicate that the venom of P. occidentalis might contain active neurotoxins that can be used as pharmacological sources for anticonvulsant drug design.
Correspondence to: mmortari@usp.br