The alkaloid extract (AE) of Huperzia saururus is constituted by a mixture of alkaloids, three of which occur as a majority: sauroine, sauroxine and 6-OH-lycopodine. In previous investigations we demonstrated that AE shows a facilitating effect on the LTP generation, as well as it was proved for sauroine, so this alkaloids it is one of the responsible for the AE activity. On the contrary, we reported that sauroxine inhibits the LTP phenomena at a concentration of 1 µg/mL. Literature references indicate that there are compounds that inhibit the LTP generation at certain concentrations whereas at lesser ones they produce facilitation.
In view of these antecedents we evaluate sauroxine at a lesser concentration (0,5 µg/mL). Results showed that at this dose the alkaloid is still inhibiting the LTP. Controls showed an average threshold of 75±11.0 Hz, whereas when it was perfused with sauroxine not LTP generation was achieved, even stimulating until 200 Hz.
Further experiments at other doses will be assayed in order to determine whether sauroxine has a dual effect or definitely produce an inhibition on the LTP generation.
