Gomisin N isolated from Schisandra chinensis augments pentobarbital-induced sleep behaviors through the modification of the serotonergic and GABAergic system.

The fruits of Schisandra chinensis have been used for the treatment of insomnia in oriental countries for more than thousands of years. However, the pharmacological properties and the mechanism of sedative and hypnotic effects have not yet been studied. Gomisin N is one of the major bioactive constituents from the fruits of Schisandra chinensis, and in this paper we reported a detailed study on the effects and mechanisms of Gomisin N on its sedative and hypnotic activity for the first time. These results implied that Gomisin N possessed weak sedative effects on locomotion activity in normal mice, and produced a dose-dependent(5-45 mg/kg, i.p.) increase in sleep duration in pentobarbital-treated mice, thus, itself did not induce sleep at higher dose which was used in this experiment (45 mg/kg, i.p.). It also can reverse the rodent models of insomnia induced by p-chlorophenylalanine (PCPA) and caffeine, which could exhibit a synergistic effect with 5-hydroxytryptophan (5-HTP) as well; furthermore, the hypnotic effects of Gomisin N were inhibited by flumazenil (a specific GABAA-BZD receptor antagonist). Altogether, these results indicated that Gomisin N produced beneficial sedative and hypnotic bioactivity, which might be mediated by the modification of the serotonergic and GABAergic system.