EFFECTS OF SCHIZANDROL A ON THE CENTRAL NERVOUS SYSTEM

Schizandrol A is one of the active constituents isolated from the ethanol extract of the dried fruit of Schizandra chinensis Baill(Fructus schizandras). Intraperitoneal injection of a dose of 1/10 LD₅₀ of schizandrol A in mice prolonged the sleeping time induced by pentobarbital or barbital. In doses of 1/50 LD₅₀, schizandrol A decreased the mice spontaneous motor activity (SMA). Schizandrol A also enhanced the inhibiting effects of chlorpromazine, reserpine and pentobarbital, and antagonisted the stimulating effects of amphetamine and coffeine on SMA in mice. The ID_50s of schizandrol A on tonic convulsion induced by electric shock (MES), metrazol, nicotine and hydrastine were 55, 51, 58, and 82 mg/Kg respectively, and those on foot shock aggression and isolated aggression in mice were 99 mg/Kg and 35 mg/Kg. The specific avoidance-blocking activity produced by neuroleptics was also produced by schizandrol A in rats. When schizandrol A was given at higher doses to rats, catalepsy was observed which could be prevented by prior intraventricular injection of dopamine. These experimental results indicate that schizandrol A posseses extensive inhibiting effects on the CNS which is charateristic for neuroleptics.