Sauroxine impairs the memory retention in step-down test.

MARIANA VALLEJOS; GABRIELA ORTEGA; VALERIA PAOLA CARLINI; JOSE CABRERA; SUSANA RUBIALES DE BARIOGLIO; MARIEL AGNESE

Saô Paulo, Brasil

Congreso; XX Symposium of Brazilian Medicinal Plants and X Internacional Congreso of Ethnopharmacology.; 2008

INTRODUCTION: Huperzia saururus (Lam.) Trevis. (Lycopodiaceae)is reported in Argentinean popular medicine as an aphrodisiac and memory improver. Sauroine and sauroxine (Sx) are two of the majority alkaloids of the H. saururus alkaloid extract (AE). In previous studies we demonstrated that AE increases the memory retention in the step-down test (Vallejo M. et al., 2007, Biocell 31, 102) as well as sauroine being therefore one of the responsible alkaloids of the activity proved for AE. In this opportunity the Sx effects on memory retention was assayed. METHODOLOGY: Sx was obtained by means of extractive and combination of chromatographic techniques. Its identification was achieved by Vallejo M. et al., 2007, Biocell 31, 101. Posterior, a solution of Sx 1mg/mL in artificial cerebro spinal fluid (ACSF) was used. Male Wistar rats were implanted bilaterally into the hippocampus and injected immediately post training with ACSF (controls, n=8) or Sx (1ng/rat; n=6). Twenty hours after the animals were tested for memory retention. Results are expressed as latency time mean ± the interquartil range (the time that the animals step down placing the four paws on the grid) in seconds (sec) and analyzed by a non parametric ANOVA followed by a post hoc analysis (Kruskal Wallis). RESULTS: Sx significantly decrease the latency time in relation to control animals (Sx: 8.01± (2.99 ? 14.75) vs. ACSF: 24.0± (14.5 ? 40.0) sec). DISCUSSION: Our results showing that Sx 1mg/mL impair memory retention in the behavioral paradigm are in accordance with previous our studies in vitro that demonstrated that Sx (at 0.5 and 1 µg/mL)induces blockage in Long Term Potentiation (LTP) ), in rat hippocampal slices