Neuroprotective action of Rs5 from Rhinella schneideri poison
Mateus Amaral Baldo Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences, Ribeirão Preto USP. Department of Biology, Faculty of Philosophy, Sciences and Letters, Ribeirão Preto - USP, Ribeirão Preto-SP, Brazil
Abstract:
Parotoid gland secretions from toads are useful source of chemical compounds with potential medical-pharmaceutical applications. The aim of this study was to isolate and characterize the component from Rhinella schneideri (Rs) poison with anticonvulsivant activity. The poison was obtained by compression of parotoid glands, filtered and low molecular mass components were submitted to chromatography in HPLC system using C2C18 column. Five fractions were obtained and Rs5 showed neuroprotective action. Male Wistar rats (250 g) were cannulated in the right lateral ventricle, following stereotactic coordinates. After recovery, rats were divided into groups (n=6) and the control animals received injections of saline (0.9%; i.c.v.) followed by the convulsant PTZ (80 mg/kg,i.p.) or NMDA (20 µg/µL, i.c.v.). Experimental groups were treated with Rs5 at different concentrations (0.05, 0.1, 0.25, 0.5, 1, 1.5 and 2 µg/µL; i.c.v.). Data showed that pretreatment with Rs5 at concentrations of 0.5, 1, 1.5 and 2 µg/µL protected 40, 60, 84 and 100% of rats against tonic-clonic seizures induced by PTZ, respectively. Additionally, 50, 62, 62, 83 e 100% of those treated with Rs5 at concentrations of 0.05, 0.1, 0.5, 1 and 2 µg/µL, respectively, were protected of seizures induced by NMDA.
