ABSTRACT
This research was designed to identify whether Gastrodiae Rhizoma ethanol extract (GREE) enhances pentobarbital-induced sleep via γ-aminobutyric acid- (GABA-) ergic systems and modulated sleep architectures in animals. GREE (25, 50, and 100 mg/kg, p.o.) inhibited locomotor activity in mice, in a dose-dependent manner. GREE not only prolonged total sleep time, but also reduced sleep latency time in pentobarbital (42 mg/kg)-treated mice. Subhypnotic pentobarbital (28 mg/kg, i.p.) also increased the number of total sleeping animals in concomitant administration of GREE. GREE (100 mg/kg) alone reduced the count of sleep-wake cycles in electroencephalogram. Furthermore, GREE increased total sleep time and rapid eye movement (REM) sleep. From the in vitro experiments, GREE increased intracellular chloride level in primary cultured cerebellar granule cells. Protein expressions of glutamine acid decarboxylase (GAD) and GABAA receptors subtypes by western blot were increased. Therefore, our study suggested that GREE enhances pentobarbital-induced sleeping behaviors and increased REM via the activation of GABAA-ergic transmission in rodents.
ABSTRACT
ETHNOPHARMACOLOGICAL RELEVENCE: The ginseng root has been traditionally used as a sedative in oriental countries. However, the condition "ginseng abuse syndrome" (GAS), defined as hypertension, nervousness, sleeplessness, skin eruption, and morning diarrhea, was coined as a result of a study of people who had been using a variety of ginseng preparations. However, we reported that administration of RGE increased rapid eye movement (REM) and non rapid eye movement (NREM) sleep via GABAergic systems in animals. Therefore, this study was performed to investigate how red ginseng extract (RGE) affects sleeping behaviors in human volunteers. MATERIALS AND METHODS: RGE (1500 mg) was orally administered to young male healthy volunteers (from 15 to 37 years old ages, n=15) three times a day for 7 days. Overnight polysomnographic (PSG) studies were performed two times, 1 day before and 7 days after RGE administration. We investigated differences in sleep architecture parameters such as total sleep time (TST), sleep efficacy (SE: total sleep time/time in bed), proportion of each sleep stage, and wakefulness after sleep onset (WASO) between baseline PSG and PSG after RGE administration. RESULTS: Total wake time (TWT) was significantly reduced (P<0.05) and SE was increased (P<0.05), although slow wave sleep stage 1 (N1) was reduced (P<0.01) and non-rapid eye movement (REM) sleep was increased (P<0.03) after administration. CONCLUSION: From these results, it is presumed that RGE intake would improve the quality of sleep, thus having beneficial effects on sleep disturbed subjects.