Neuroprotective effects of Ptychopetalum olacoides Bentham (Olacaceae) on oxygen and glucose deprivation induced damage in rat hippocampal slices Ionara R. Siqueira a,b, * , Helena Cimarosti c , Cı ´ntia Fochesatto c , Domingos S. Nunes d , Christianne Salbego c , Elaine Elisabetsky a,e , Carlos A. Netto a,c a Programa de Po ´s-Graduac ßa ˜o em Cie ˆncias Biolo ´gicas-Fisiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil b Centro Universita ´rio UNIVATES, Lajeado, RS, Brazil c Departamento de Bioquı ´mica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil d Departamento de Quı ´mica, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil e Departamento de Farmacologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil Received 18 January 2004; accepted 3 June 2004 Abstract Alcoholic infusions of Ptychopetalum olacoides Bentham (PO, Olacaceae) are used in traditional medicine by patients presenting age associated symptoms and those recovering from stroke. The aim of this study is to evaluate the neuroprotective properties of PO ethanol extract (POEE) using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation). Mitochondrial activity, an index of cell viability, was assessed by the MTT assay; in addition, the free radicals content was estimated by the use of dichlorofluorescein diacetate as probe. The OGD ischemic condition significantly impaired cellular viability, and increased free radicals generation. In non-OGD slices, incubation with POEE (0.6 Ag/ml) increased (c 40%) mitochondrial activity, without affecting free radicals levels. In comparison to OGD controls, slices incubated with POEE (0.6 Ag/ml) during and after OGD exposure had significantly increased cellular viability. In addition, at this same concentration, POEE prevented the increase of free radicals content induced by OGD. In view of the fact that respiratory chain inhibition and increased generation of free radicals are major consequences of the ischemic injury, this 0024-3205/$ - see front matter D 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.lfs.2004.06.001 * Corresponding author. Departamento III, Centro Universita ´rio UNIVATES, Rua Barbedo 426, 03, 90110-260, Porto Alegre, RS, Brazil. Tel.: +55-51-3316-3664; fax: +55-51-3316-4085. E-mail address: ionara@ufrgs.br (I.R. Siqueira). www.elsevier.com/locate/lifescie Life Sciences 75 (2004) 1897 – 1906