GABA and l-theanine mixture decreases sleep latency and improves NREM sleep. (1st January 2019)

• Record Type: Journal Article
• Authors: Kim, Suhyeon; Jo, Kyungae; Hong, Ki-Bae; Han, Sung Hee; Suh, Hyung Joo
• Is Part Of: Pharmaceutical biology. Volume 57:Number 1(2019)
• Page Start: 64
• Page End: 72
• Publication Date: 2019-01-01
• Subjects: γ-Aminobutyric acid -- insomnia -- pentobarbital-induced sleep test -- electroencephalography; Pharmacognosy -- Periodicals; Materia medica, Vegetable -- Periodicals; 615.321
• DOI: 10.1080/13880209.2018.1557698
• Languages: English
• ISSNs: 1388-0209

Abstract

Abstract: Context: γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter and it is well established that activation of GABAA receptors favours sleep. l -Theanine, a naturally occurring amino acid first discovered in green tea, is a well-known anti-anxiety supplement with proven relaxation benefits. Objective: This study investigated the potential synergistic sleep enhancement effect of GABA/l -theanine mixture. Materials and methods: Pentobarbital-induced sleep test was applied to find proper concentration for sleep-promoting effect in ICR mice. Electroencephalogram (EEG) analysis was performed to investigate total sleeping time and sleep quality in normal SD rats and caffeine-induced awareness model. Real-time polymerase chain reaction (RT-PCR) was applied to investigate whether the sleep-promoting mechanism of GABA/l -theanine mixture involved transcriptional processes. Results: GABA/l -theanine mixture (100/20 mg/kg) showed a decrease in sleep latency (20.7 and 14.9%) and an increase in sleep duration (87.3 and 26.8%) compared to GABA or theanine alone. GABA/l -theanine mixture led to a significant increase in rapid eye movement (REM) (99.6%) and non-REM (NREM) (20.6%) compared to controls. The use of GABA/l -theanine mixture rather than GABA or l -theanine alone restored to normal levels sleep time and quality in the arousal animal model. The administration of GABA/l -theanine led to increased expression of GABA and the glutamate GluN1 receptor subunit. Conclusions: GABA/l -theanine mixture has a positive synergistic effect on sleep quality and duration as compared to the GABA or l -theanine alone. The increase in GABA receptor and GluN1 expression is attributed to the potential neuromodulatory properties of GABA/l -theanine combination, which seems to affect sleep behaviour.