Behavioral and molecular evidence for psychotropic effects in l-theanine

Wakabayashi, Chisato; Numakawa, Tadahiro; Ninomiya, Midori; Chiba, Shuichi

doi:10.1016/j.neures.2011.07.858

Cited by 11 publications

(18 citation statements)

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“…Moreover, an epidemiological investigation in older adults has demonstrated an association between poor diet and reduced hippocampal volume (15) . In addition to possessing antioxidant and anti-inflammatory properties, nutrients, such as n-3 fatty acids (32) , polyphenols (33) , l-theanine (34) and vitamin E (35) , can also stimulate neurogenesis while energy-dense diets high in fat and sugar impair this process (21,36,37) .…”

Section: Brain Plasticitymentioning

confidence: 99%

Nutritional psychiatry: the present state of the evidence

et al. 2017

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Mental illness, including depression, anxiety and bipolar disorder, accounts for a significant proportion of global disability and poses a substantial social, economic and heath burden. Treatment is presently dominated by pharmacotherapy, such as antidepressants, and psychotherapy, such as cognitive behavioural therapy; however, such treatments avert less than half of the disease burden, suggesting that additional strategies are needed to prevent and treat mental disorders. There are now consistent mechanistic, observational and interventional data to suggest diet quality may be a modifiable risk factor for mental illness. This review provides an overview of the nutritional psychiatry field. It includes a discussion of the neurobiological mechanisms likely modulated by diet, the use of dietary and nutraceutical interventions in mental disorders, and recommendations for further research. Potential biological pathways related to mental disorders include inflammation, oxidative stress, the gut microbiome, epigenetic modifications and neuroplasticity. Consistent epidemiological evidence, particularly for depression, suggests an association between measures of diet quality and mental health, across multiple populations and age groups; these do not appear to be explained by other demographic, lifestyle factors or reverse causality. Our recently published intervention trial provides preliminary clinical evidence that dietary interventions in clinically diagnosed populations are feasible and can provide significant clinical benefit. Furthermore, nutraceuticals including n-3 fatty acids, folate, S-adenosylmethionine, N-acetyl cysteine and probiotics, among others, are promising avenues for future research. Continued research is now required to investigate the efficacy of intervention studies in large cohorts and within clinically relevant populations, particularly in patients with schizophrenia, bipolar and anxiety disorders.

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Section: Brain Plasticitymentioning

confidence: 99%

Nutritional psychiatry: the present state of the evidence

et al. 2017

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“…In mouse models of depression, green tea triggers antidepressive‐like and antioxidant activity effects (Di Lorenzo et al, ), and theanine is accounted for improvements in two standard antidepressive screening tests, namely, forced swim test (FST) and tail suspension test (Takarada et al, ; Yin et al, ). L ‐theanine administration increases brain‐derived neurotrophic factor expression in the hippocampus (HIP) and modulates the activity of brain neurotransmitters, such as 5‐HT, DA, and γ‐aminobutyric acid (Tamano et al, ; Wakabayashi, Numakawa, Ninomiya, Chiba, & Kunugi, ; Yamada et al, ; Yokogoshi, Kobayashi, Mochizuki, & Terashima, ; Yokogoshi et al, ). Although previous findings have indicated that l ‐theanine is a potent antidepressant, the detailed mechanisms of its effects remain poorly understood.…”

Section: Introductionmentioning

confidence: 99%

L‐theanine ameliorate depressive‐like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic–cortical–striatal–pallidal–thalamic‐circuit related brain regions

Shen

Yang

Ying

et al. 2018

Phytotherapy Research

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L-theanine, originally found in green tea, elicits various physiological effects, such as promoting relaxation, improving concentration and learning ability, and providing antianxiety-like and antidepressant-like properties. This study aims to investigate the effects of L-theanine (2 mg/kg) on monoamine levels in an animal model of depression. The effect of L-theanine on the symptoms of depression was examined through the open-field test, sucrose preference test, and forced swim test. The monoamine neurotransmitters that involve serotonin (5-HT), norepinephrine (NE), and dopamine (DA) were measured in the limbic-cortical-striatal-pallidal-thalamic (LCSPT)-circuit related brain regions, including the prefrontal cortex (PFC), nucleus accumbens (NAC), striatum (ST), amygdala, and hippocampus (HIP). L-theanine ameliorated the depressive-like behaviors in the chronic unpredictable mild stress (CUMS)rat model. In the PFC, NAC, and HIP, L-theanine administration significantly increased the levels of 5-HT, NE, and DA. In the ST, the levels of 5-HT and DA were increased after the administration of L-theanine. However, in the HIP, only the level of DA significantly changed after the treatment of L-theanine. Taken together, these results indicated that L-theanine has possibly antidepressant-like effects in the CUMS rat model, which could be mediated by the monoamine neurotransmitters in the LCSPT-circuit related brain regions.

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“…In this line, it has been shown that the excitatory action of L-theanine on cortical neurons can be blocked by NMDA receptor antagonists. 14 This could explain the beneficial action of L-theanine in a rodent model of schizophrenia induced by NMDA receptor hypofunction. Indeed, NMDA receptors are widely expressed on inhibitory interneurons.…”

Section: ■ Introductionmentioning

confidence: 99%

Characterization of l-Theanine Excitatory Actions on Hippocampal Neurons: Toward the Generation of Novel N-Methyl-d-aspartate Receptor Modulators Based on Its Backbone

Sebih

Rousset

Bellahouel

et al. 2017

ACS Chem. Neurosci.

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l-Theanine (or l-γ-N-ethyl-glutamine) is the major amino acid found in Camellia sinensis. It has received much attention because of its pleiotropic physiological and pharmacological activities leading to health benefits in humans, especially. We describe here a new, easy, efficient, and environmentally friendly chemical synthesis of l-theanine and l-γ-N-propyl-Gln and their corresponding d-isomers. l-Theanine, and its derivatives obtained so far, exhibited partial coagonistic action at N-methyl-d-aspartate (NMDA) receptors, with no detectable agonist effect at other glutamate receptors, on cultured hippocampal neurons. This activity was retained on NMDA receptors expressed in Xenopus oocytes. In addition, both GluN2A and GluN2B containing NMDA receptors were equally modulated by l-theanine. The stereochemical change from l-theanine to d-theanine along with the substitution of the ethyl for a propyl moiety in the γ-N position of l- and d-theanine significantly enhanced the biological efficacy, as measured on cultured hippocampal neurons. l-Theanine structure thus represents an interesting backbone to develop novel NMDA receptor modulators.

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Behavioral and molecular evidence for psychotropic effects in l-theanine

Cited by 11 publications

References 0 publications

Nutritional psychiatry: the present state of the evidence

Nutritional psychiatry: the present state of the evidence

L‐theanine ameliorate depressive‐like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic–cortical–striatal–pallidal–thalamic‐circuit related brain regions

Characterization of l-Theanine Excitatory Actions on Hippocampal Neurons: Toward the Generation of Novel N-Methyl-d-aspartate Receptor Modulators Based on Its Backbone

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