GABA and l-theanine mixture decreases sleep latency and improves NREM sleep

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.

Psychotropic effects of L-theanine and its clinical properties: From the management of anxiety and stress to a potential use in schizophrenia

“…Beta waves are common in alert, awake adults, but also predominant in situations which demand intense mental effort. Corroborating such findings, studies employing animal models have found that the administration of L-theanine seems to increase GABA levels in the brain [43,49].…”

“…however, despite the acknowledged debate in the topic, some researchers suggest that the blood brain barrier is permeable to GABA [41,42]. In that sense, Kim and colleagues showed that there is a synergistic sleep enhancement effect of orally administered GABA/L-theanine mixture, whose combination has led to decreased sleep latency and improved NREM sleep in mice, when compared to their individual administration [43]. Taking into account the combination of L-theanine administration with other supplements which claim sleep-promoting effects, GABA for example, further studies are required to prove or disprove its clinical relevance.…”

A New Hypothesis on Anxiety, Sleep Insufficiency, and Viral Infections; Reciprocal Links to Consider in Today's “World vs. COVID-19” Endeavors

“…Valerenic acid, in particular, has a high binding affinity for the GABA A receptor in neurons, similarly as the benzodiazepine class of tranquilizer drugs (75). GABA A receptor activation promotes NREM sleep and significantly increases REM sleep (76). Recent studies also show that velerenic acid mitigates physical and psychological stress by reducing serum corticosterone levels and turnover of serotonin and norepinephrine, in addition to increasing BDNF levels in neuronal cells (77,78).…”

Creatine and taurine mixtures alleviate depressive-like behaviour in Drosophila melanogaster and mice via regulating Akt and ERK/BDNF pathways

“…The cycling conditions were 50 °C for 2 min, 95 °C for 10 min, followed by 40 cycles of 95 °C for 15 s, and 60 °C for 1 min. Quantitative analysis was conducted using the Step-One-Plus Software version 2.0 (Applied Biosystems) 61 . The endogenous housekeeping gene, GAPDH, was used for result normalisation.…”