Schisandra chinensis is a
traditional Chinese medicine that has been used for treating
insomnia and
neurasthenia for centuries.
Lignans, which are considered to be the bioactive components, are
apt to be extracted by supercritical
carbon dioxide. This study was conducted to investigate the
sedative and hypnotic activities of the supercritical
carbon dioxide fluid extraction of S. chinensis (SFES) in mice and the possible mechanisms. SFES exhibited an obvious
sedative effect on shortening the locomotor activity in mice in a dose-dependent (10-200 mg/kg) manner. SFES (50 mg/kg, 100 mg/kg, and 200 mg/kg, intragstrically) showed a strong
hypnotic effect in synergy with
pentobarbital in mouse sleep, and reversal of
insomnia induced by
caffeine,
p-chlorophenylalanine and
flumazenil by decreasing sleep latency, sleep recovery, and increasing sleeping time. In addition, it produced a synergistic effect with
5-hydroxytryptophan (2.5 mg/kg, intraperitoneally). The behavioral pharmacological results suggest that SFES has significant
sedative and hypnotic activities, and the mechanisms might be relevant to the serotonergic and γ-
aminobutyric acid (
GABA)ergic system.