Central Nervous System Effects of Iso-6-spectaline Isolated from Senna Spectabilis var. Excelsa (Schrad) in Mice

The central nervous system (CNS) depressant and anticonvulsant activities of iso-6-spectaline (SPEC) were investigated in animal models. The SPEC from Senna spectabilis var. excelsa (Schrad) (0.1, 0.5 and 1.0 mg/ kg) injected by oral route (p.o.) in mice caused a significant decrease in the motor activity up to 30 days after the administration and in the dose of 1.0 mg/kg significantly reduced the remaining time on the Rota-rod apparatus. Additionally, SPEC (0.1, 0.5 and 1.0 mg/kg, p.o.) was also capable of promoting increase of latency for development of convulsions induced by pentylenetetrazole. This SPEC was also capable of promoting an increase of latency for development of convulsions induced by picrotoxin at highest dose. In the same way, the anticonvulsant effect of SPEC was affected by pretreatment with flumazenil, a selective antagonist of the benzodiazepine site of the GABA(A) receptor. These results suggest possible CNS depressant and anticonvulsant activities in mice that needs further investigation.