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Baba Y, Takihara T, Okamura N. Matcha Does Not Affect Electroencephalography during Sleep but May Enhance Mental Well-Being: A Randomized Placebo-Controlled Clinical Trial. Nutrients 2024; 16:2907. [PMID: 39275223 PMCID: PMC11397442 DOI: 10.3390/nu16172907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2024] [Revised: 08/23/2024] [Accepted: 08/28/2024] [Indexed: 09/16/2024] Open
Abstract
Although theanine in matcha improves sleep quality and cognitive function, the caffeine in green tea is thought to worsen sleep quality. Therefore, this study investigated the factors behind the observed improvements in subjective sleep quality in matcha. A placebo-controlled randomized double-blind parallel-group study was conducted on healthy Japanese men and women aged 27-64 years. After 4 weeks of consuming 2.7 g of matcha daily (containing 50.3 mg theanine, 301.4 mg catechins, and 71.5 mg caffeine), no significant differences were observed between the control and matcha groups on total sleep time, sleep latency, wake after sleep onset, or sleep efficiency measured by electroencephalography (EEG). However, the sleep questionnaire Oguri-Shirakawa-Azumi Sleep Inventory, the Middle-age and Aged version (OSA-MA), administered immediately after waking showed a trend toward increased satisfaction with sleep time (p < 0.1), and EEG measurements indicated significantly shortened wake-up times after waking with matcha intake (p < 0.05). The Beck Depression Inventory-II scores also tended to decrease (p < 0.1). The continuous intake of matcha may offer improved subjective sleep quality and emotional stability despite not offering significant changes in objective sleep parameters.
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Affiliation(s)
- Yoshitake Baba
- Central Research Institute, ITO EN, Ltd., 21 Mekami, Makinohara 421-0516, Shizuoka, Japan
| | - Takanobu Takihara
- Central Research Institute, ITO EN, Ltd., 21 Mekami, Makinohara 421-0516, Shizuoka, Japan
| | - Noritaka Okamura
- Department of Medical Technology, Faculty of Health Sciences, Ehime Prefectural University of Health Sciences, 543 Takoda, Tobe-cho 791-2101, Iyo-Gun, Japan
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Li Y, Jiang Y, Zhang Z, Loake VIP, Bao X, Loake GJ. Improvement of both human and animal memory by synergy between fructooligosaccharide and L-theanine function establishing a safe and effective food supplement. Food Sci Nutr 2024; 12:4966-4980. [PMID: 39055226 PMCID: PMC11266938 DOI: 10.1002/fsn3.4145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/24/2024] [Accepted: 03/19/2024] [Indexed: 07/27/2024] Open
Abstract
Aging is classically associated with a decline of cognitive abilities, especially in relation to memory. While the development of potential treatments for neurodegenerative diseases has been in sharp focus, mild cognitive impairment (MCI), a form of age-related memory loss, in the absence of severe functional impairment, a condition experienced by many healthy adults, has received relatively little attention. Advances in this space would make significant contributions to the goal of healthy aging and may also help promote cognitive performance across the wider population. The individual action of either fructooligosaccharide (FOS) or L-theanine, both natural plant-derived molecules, has been tentatively linked with improvements in cognition, but our understanding remains far from complete. We therefore determined the effect of different dose combinations of FOS and L-theanine (termed MT-01/GBL-Memory1) in mice against FOS and L-theanine monotherapy. FOS and L-theanine were found to synergistically enhance murine memory in our animal tests at a dose of 100 mg/kg (coefficient of drug interaction (CDI) < 1). In a subsequent human trial, we demonstrated that MT-01 improved the memory of healthy adults after 1 month of consumption. Our results suggest that a combination of FOS and L-theanine synergistically enhances murine memory within a specific dose range. We show that this plant natural product regimen also improves human memory in a population of healthy adults. MT-01 therefore represents a novel, safe, and effective dietary supplement to promote human memory and cognition.
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Affiliation(s)
- Yuan Li
- Green Bioactives Limited, Pentland Science ParkPenicuikUK
| | - Yuying Jiang
- Department of Pharmacology, West China School of PharmacySichuan UniversityChengduChina
| | - Zubing Zhang
- Yiping Medical Science & Technology Development Co. LtdChengduChina
| | | | - Xu Bao
- Department of Pharmacology, West China School of PharmacySichuan UniversityChengduChina
| | - Gary J. Loake
- Green Bioactives Limited, Pentland Science ParkPenicuikUK
- Institute of Molecular Plant Sciences, School of Biological SciencesUniversity of EdinburghEdinburghUK
- Centre for Engineering Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
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Nematizadeh M, Ghorbanzadeh H, Moghaddam HS, Shalbafan M, Boroon M, Keshavarz-Akhlaghi AA, Akhondzadeh S. L-theanine combination therapy with fluvoxamine in moderate-to-severe obsessive-compulsive disorder: A placebo-controlled, double-blind, randomized trial. Psychiatry Clin Neurosci 2023; 77:478-485. [PMID: 37169515 DOI: 10.1111/pcn.13565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 04/19/2023] [Accepted: 05/08/2023] [Indexed: 05/13/2023]
Abstract
AIM The main aim of this study was to investigate the additional effects of L-theanine, an amino acid in tea and an analog of glutamate with neuroprotective and anti-depressant properties, on obsessive-compulsive disorder (OCD) symptoms in combination with fluvoxamine. METHODS Patients from either sex aged between 18 and 60 years diagnosed with OCD, based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), who had a Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score of more than 21 were enrolled in a double-blinded, parallel-group, placebo-controlled, clinical trial of 10 weeks to receive either L-theanine (100 mg twice daily) and fluvoxamine (100 mg daily initially followed by 200 mg daily after week 5) or placebo and fluvoxamine. The primary outcome of interest in this study was the Y-BOCS total score decrease from baseline. RESULTS From a total of 95 evaluated patients, 50 completed our study; 30 were randomly assigned to each group. Multivariate analysis (ANOVA) showed a significant effect of time× $$ \times $$ treatment for L-theanine in obsession subscale (F = 5.51, P = 0.008) of the Y-BOCS score but not in the total and compulsion scores. Our results showed significantly more improvement in obsession subscale scores in L-theanine compared to placebo group (P = 0.007, Cohen's d = 0.82). Also, total Y-BOCS scores were lower in L-theanine compared to placebo group at week 5 (P = 0.039, Cohen's d = 0.60) and 10 (P = 0.008, Cohen's d = 0.80). However, there was no significant between-group differences in compulsion subscale scores. Complete response was also more frequent in the L-theanine group (P = 0.0001). CONCLUSION Findings in this study suggest L-theanine as a relatively safe and effective adjuvant therapy for moderate to severe OCD.
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Affiliation(s)
- Mehran Nematizadeh
- Psychiatric Research Center, Roozbeh Psychiatric Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Ghorbanzadeh
- Psychiatric Research Center, Roozbeh Psychiatric Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Sanjari Moghaddam
- Psychiatric Research Center, Roozbeh Psychiatric Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammadreza Shalbafan
- Mental Health Research Center, Psychosocial Health Research Institute (PHRI), Department of Psychiatry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mahsa Boroon
- Mental Health Research Center, Psychosocial Health Research Institute (PHRI), Department of Psychiatry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Amir-Abbas Keshavarz-Akhlaghi
- Mental Health Research Center, Psychosocial Health Research Institute (PHRI), Department of Psychiatry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Shahin Akhondzadeh
- Psychiatric Research Center, Roozbeh Psychiatric Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Baba Y, Takihara T, Okamura N. Theanine maintains sleep quality in healthy young women by suppressing the increase in caffeine-induced wakefulness after sleep onset. Food Funct 2023; 14:7109-7116. [PMID: 37458751 DOI: 10.1039/d3fo01247f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
Energy drinks take advantage of caffeine's effects on wakefulness and performance; however, excessive intake has a negative effect on sleep. Green tea is consumed worldwide and has both a stimulating effect from caffeine and a calming or relaxing effect from theanine. Theanine reduces the excitotoxicity of caffeine. This study evaluated whether theanine improves the sleep quality worsened by caffeine in healthy young women. Sleep latency, sleep time, wake after sleep onset (WASO) time, and the number of WASOs were measured. A crossover study was performed using four treatment groups: theanine (50 mg), caffeine (30 mg), combined theanine and caffeine (TC), and placebo. The sleep stage was determined using electroencephalograms, and cerebral blood flow was measured using near-infrared spectroscopy. The caffeine group showed a significant increase in the WASO time compared with the placebo group; no difference was observed between the theanine or TC group and the placebo group. There were no differences in the sleep-onset latency or number of WASOs between the theanine, caffeine, or TC groups and the placebo group. In combination with theanine, only the caffeine-induced increase in the WASO time was suppressed. Our results suggest that theanine can reduce caffeine's effects on sleep quality.
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Affiliation(s)
- Yoshitake Baba
- Central Research Institute, ITO EN, Ltd, 21 Mekami, Makinohara, Shizuoka 421-0516, Japan.
| | - Takanobu Takihara
- Central Research Institute, ITO EN, Ltd, 21 Mekami, Makinohara, Shizuoka 421-0516, Japan.
| | - Noritaka Okamura
- Ehime Prefectural University of Health Sciences, 543 Takoda, Tobe-Cho, Iyo-Gun, Ehime 791-2101, Japan.
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Jiang N, Ma J, Wang Q, Xu Y, Wei B. Tea intake or consumption and the risk of dementia: a meta-analysis of prospective cohort studies. PeerJ 2023; 11:e15688. [PMID: 37483967 PMCID: PMC10361076 DOI: 10.7717/peerj.15688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/14/2023] [Indexed: 07/25/2023] Open
Abstract
Purpose Dementia affects as many as 130 million people, which presents a significant and growing medical burden globally. This meta-analysis aims to assess whether tea intake, tea consumption can reduce the risk of dementia, Alzheimer's disease (AD) and Vascular dementia (VD). Patients and methods Cochrane Library, PubMed and Embase were searched for cohort studies from inception to November 1, 2022. The Newcastle Ottawa Quality Assessment Scale (NOS) was applied to evaluate the risk of bias of the included studies. We extracted the data as the relative risks (RRs) for the outcome of the interest, and conducted the meta-analysis utilizing the random effect model due to the certain heterogeneity. Sensitivity analysis were performed by moving one study at a time, Subgroup-analysis was carried out according to different ages and dementia types. And the funnel plots based on Egger's and Begger's regression tests were used to evaluate publication bias. All statistical analyses were performed using Stata statistical software version 14.0 and R studio version 4.2.0. Results Seven prospective cohort studies covering 410,951 individuals, which were published from 2009 and 2022 were included in this meta-analysis. The methodological quality of these studies was relatively with five out of seven being of high quality and the remaining being of moderate. The pooling analysis shows that the relationship between tea intake or consumption is associated with a reduced risk of all-cause dementia (RR = 0.71, 95% CI [0.57-0.88], I2 = 79.0%, p < 0.01). Further, the subgroup-analysis revealed that tea intake or consumption is associated with a reduced risk of AD (RR = 0.88, 95% CI [0.79-0.99], I2 = 52.6%, p = 0.024) and VD (RR = 0.75, 95% CI [0.66-0.85], I = 0.00%, p < 0.001). Lastly, tea intake or consumption could reduce the risk of all-cause dementia to a greater degree among populations with less physical activity, older age, APOE carriers, and smokers. Conclusion Our meta-analysis demonstrated that tea (green tea or black tea) intake or consumption is associated with a significant reduction in the risk of dementia, AD or VD. These findings provide evidence that tea intake or consumption should be recognized as an independent protective factor against the onset of dementia, AD or VD.
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Affiliation(s)
- Ning Jiang
- School of Nursing, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong, China
| | - Jinlong Ma
- Yanbian University, Yanbian, Jilin, China
| | - Qian Wang
- Postdoctoral Workstation, Department of Central Laboratory, The Affiliated Taian City Central Hospital of Qingdao University, Taian, Shandong, China
| | - Yuzhen Xu
- The Second Affiliated Hospital, Shandong First Medical University, Taian, Shandong, China
| | - Baojian Wei
- School of Nursing, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong, China
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Simkin DR, Swick S, Taneja KS, Ranjbar N. Complementary and Integrative Medicine for Anxiety in Children, Adolescents, and Young Adults. Child Adolesc Psychiatr Clin N Am 2023; 32:193-216. [PMID: 37147037 DOI: 10.1016/j.chc.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
An integrative approach to treating anxiety in children and adolescents takes a biopsychosocial-spiritual approach. Early life stress may translate into anxiety via epigenetic mechanisms, the adoption of maladaptive coping tendencies (poor eating, sedentary lifestyle, substance use), and dysregulation of central autonomic nervous system function. Each of these mechanisms may increase inflammatory markers. This article will explore the efficacy of CIM interventions that work on these mechanisms through mind-body-medicine, acupuncture, nutrition, and supplements.
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Affiliation(s)
- Deborah R Simkin
- Department of Psychiatry, Emory University School of Medicine, 8955 Highway 98 West, Suite 204, Miramar Beach, FL 32550, USA
| | - Shayna Swick
- University of Arizona College of Medicine, 2800 E Ajo Way, Behavioral Health Pavilion, 3rd Floor, Tucson, AZ 85713, USA
| | - Krishna S Taneja
- Southern Illinois University School of Medicine, 319 E Madison Street, Springfield, IL 62701, USA
| | - Noshene Ranjbar
- Department of Psychiatry, Emory University School of Medicine, 8955 Highway 98 West, Suite 204, Miramar Beach, FL 32550, USA.
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Quan W, Lin Y, Zou H, Li M, Luo J, He Z, Chen J, Liu Z. Can habitual tea drinking be an effective approach against age-related neurodegenerative cognitive disorders: A systematic review and meta-analysis of epidemiological evidence. Crit Rev Food Sci Nutr 2022; 64:5835-5851. [PMID: 36579429 DOI: 10.1080/10408398.2022.2158780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Our present knowledge about the efficacy of tea consumption in improving age-related cognitive disorders is incomplete since previous epidemiological studies provide inconsistent evidence. This unified systematic review and meta-analysis based on updated epidemiological cohort studies and randomized controlled trials (RCTs) evidence aimed to overcome the limitations of previous reviews by examining the efficacy of distinct types of tea consumption. PubMed, Embase, and MEDLINE were searched up to May 20, 2022, and 23 cohorts and 12 cross-sectional studies were included. Random-effects meta-analyses were conducted to obtain pooled RRs or mean differences with 95% CIs. The pooled RRs of the highest versus lowest tea consumption categories were 0.81 (95% CIs: 0.75-0.88) and 0.69 (95% CIs: 0.61-0.77), respectively. The pooled mean difference of four included RCTs revealed a beneficial effect of tea on cognitive dysfunction (MMSE ES: 1.03; 95% CI, 0.14-1.92). Subgroup analyses further demonstrated that green and black tea intake was associated with a lower risk of cognitive disorders in eastern countries, especially in women. The evidence quality was generally low to moderate. The present review provides insight into whether habitual tea consumption can be an effective approach against age-related neurodegenerative cognitive disorders and summarizes potential mechanisms based on currently published literature.
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Affiliation(s)
- Wei Quan
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, China
- National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Yong Lin
- National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
| | - Huiyu Zou
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, China
| | - Maiquan Li
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, China
- National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
| | - Jie Luo
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, China
| | - Zhiyong He
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Jie Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu, China
| | - Zhonghua Liu
- National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, China
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Treatment of refractory obsessive-compulsive disorder with nutraceuticals (TRON): a 20-week, open label pilot study. CNS Spectr 2022; 27:588-597. [PMID: 34165060 DOI: 10.1017/s1092852921000638] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Obsessive-compulsive disorder (OCD) is often challenging to treat and resistant to psychological interventions and prescribed medications. The adjunctive use of nutraceuticals with potential neuromodulatory effects on underpinning pathways such as the glutamatergic and serotonergic systems is one novel approach. OBJECTIVE To assess the effectiveness and safety of a purpose-formulated combination of nutraceuticals in treating OCD: N-acetyl cysteine, L-theanine, zinc, magnesium, pyridoxal-5' phosphate, and selenium. METHODS A 20-week open label proof-of-concept study was undertaken involving 28 participants with treatment-resistant DSM-5-diagnosed OCD, during 2017 to 2020. The primary outcome measure was the Yale-Brown Obsessive-Compulsive Scale (YBOCS), administered every 4 weeks. RESULTS An intention-to-treat analysis revealed an estimated mean reduction across time (baseline to week-20) on the YBOCS total score of -7.13 (95% confidence interval = -9.24, -5.01), with a mean reduction of -1.21 points per post-baseline visit (P ≤ .001). At 20-weeks, 23% of the participants were considered "responders" (YBOCS ≥35% reduction and "very much" or "much improved" on the Clinical Global Impression-Improvement scale). Statistically significant improvements were also revealed on all secondary outcomes (eg, mood, anxiety, and quality of life). Notably, treatment response on OCD outcome scales (eg, YBOCS) was greatest in those with lower baseline symptom levels, while response was limited in those with relatively more severe OCD. CONCLUSIONS While this pilot study lacks placebo-control, the significant time effect in this treatment-resistant OCD population is encouraging and suggests potential utility especially for those with lower symptom levels. Our findings need to be confirmed or refuted via a follow-up placebo-controlled study.
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Borgonetti V, Biagi M, Galeotti N, Manetti F, Governa P. Investigation on the neuroprotective effect of a cannabidiol-enriched non-psychotropic Cannabis sativa L. extract in an in vitro model of excitotoxicity. Fitoterapia 2022; 163:105315. [PMID: 36179898 DOI: 10.1016/j.fitote.2022.105315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 09/19/2022] [Accepted: 09/23/2022] [Indexed: 11/04/2022]
Abstract
The purpose of this study was to evaluate the neuroprotective effect of a cannabidiol-enriched non-psychotropic Cannabis sativa L. extract (CSE) and its main constituents, cannabidiol and β-caryophyllene. An in vitro model of glutamate-induced neuronal excitotoxicity using SH-SY5Y cells was optimized. The impact of CSE on glutamate-impaired cell viability, brain-derived neurotrophic factor release, CB1 protein expression, and ERK levels was evaluated. The involvement of CB1 modulation was verified by the cotreatment with the CB1 antagonist AM4113. CSE was able to significantly protect SH-SY5Y from glutamate-impaired cell viability, and to counteract the changes in brain-derived neurotrophic factor levels, with a mechanism of action involving ERK modulation. Moreover, CSE completely reversed the reduction of CB1 receptor expression induced by glutamate, and the presence of the CB1 antagonist AM4113 reduced CSE effectiveness, suggesting that CBr play a role in the modulation of neuronal excitotoxicity. This work demonstrated the in vitro effectiveness of CSE as a neuroprotective agent, proposing the whole cannabis phytocomplex as a more effective strategy, compared to its main constituents alone, and suggested further investigations by using more complex cell models before moving to in vivo studies.
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Affiliation(s)
- Vittoria Borgonetti
- Department of Neuroscience, Psychology, Pharmacology and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Marco Biagi
- Department of Physical Sciences, Earth and Environment, University of Siena, Siena, Italy
| | - Nicoletta Galeotti
- Department of Neuroscience, Psychology, Pharmacology and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Fabrizio Manetti
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, Siena, Italy
| | - Paolo Governa
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, University of Siena, Siena, Italy.
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A comprehensive review on bioavailability, safety and antidepressant potential of natural bioactive components from tea. Food Res Int 2022; 158:111540. [DOI: 10.1016/j.foodres.2022.111540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/12/2022] [Accepted: 06/18/2022] [Indexed: 11/22/2022]
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Huang Y, Wei Y, Xu J, Wei X. A comprehensive review on the prevention and regulation of Alzheimer's disease by tea and its active ingredients. Crit Rev Food Sci Nutr 2022; 63:10560-10584. [PMID: 35647742 DOI: 10.1080/10408398.2022.2081128] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) has brought a heavy burden to society as a representative neurodegenerative disease. The etiology of AD combines multiple factors, concluding family, gender, head trauma, diseases and social psychology. There are multiple hypotheses explaining the pathogenesis of AD such as β-amyloid (Aβ) deposition and tau hyperphosphorylation, which lead to extracellular amyloid plaques and neurofibrillary tangles in neurons. The existing therapeutic drugs have several disadvantages including single target, poor curative effect, and obvious side effects. Tea contains many bioactive components, such as tea polyphenols (TPP), L-theanine (L-TH), tea pigment, tea polysaccharides and caffeine. The epidemiological investigations have shown that drinking tea can reduce the risk of AD. The mechanisms of tea active ingredients in the prevention and regulation of AD includes reducing the generation and aggregation of Aβ; inhibiting tau aggregation and hyperphosphorylation; inhibiting neuronal apoptosis and regulate neurotransmitters; relieving oxidative stress and neuroinflammation as well as the regulation of intestinal flora. This review summarizes the different signaling pathways that tea active ingredients regulate AD. Furthermore, we propose the main limitations of current research and future research directions, hoping to contribute to the development of natural functional foods based on tea active ingredients in the prevention and treatment of AD.
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Affiliation(s)
- Yi Huang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, PR China
| | - Yang Wei
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, PR China
| | - Jia Xu
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, PR China
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, PR China
| | - Xinlin Wei
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, PR China
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Esmaeilpour-Bandboni M, Seyedpourchafi Z, Kahneh E. The Effect of Green Tea Drinking on the Depression of Elderly People. J Nurse Pract 2021. [DOI: 10.1016/j.nurpra.2021.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Effects of Daily Matcha and Caffeine Intake on Mild Acute Psychological Stress-Related Cognitive Function in Middle-Aged and Older Adults: A Randomized Placebo-Controlled Study. Nutrients 2021; 13:nu13051700. [PMID: 34067795 PMCID: PMC8156288 DOI: 10.3390/nu13051700] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 01/26/2023] Open
Abstract
Matcha, a type of green tea, has a higher amino acid content than other types of tea. We previously examined the ability of matcha to improve cognitive function in older adults and determined that continuous matcha intake improves attention and executive function. This study aimed to compare the effects of matcha and caffeine and clarify the differences between these effects. The study was registered at the University Hospital Medical Information Network (UMIN000036578). The effect of single and continuous intake was compared, and the usefulness of continuous intake was evaluated under the stress condition. The Uchida-Kraepelin test (UKT) was used to induce mild acute stress, and the Cognitrax was used to evaluate cognitive function. A single dose of caffeine improved attentional function during or after stress loading. The reduced reaction time in the Cognitrax, observed following a single dose of matcha, was likely due to caffeine. The matcha group showed an increase in the amount of work after continuous intake, whereas the caffeine group only showed an increase in the amount of work for the UKT after a single dose. Ingesting matcha with caffeine improves both attention and work performance when suffering from psychological stress compared with caffeine alone.
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De Felice M, Renard J, Hudson R, Szkudlarek HJ, Pereira BJ, Schmid S, Rushlow WJ, Laviolette SR. l-Theanine Prevents Long-Term Affective and Cognitive Side Effects of Adolescent Δ-9-Tetrahydrocannabinol Exposure and Blocks Associated Molecular and Neuronal Abnormalities in the Mesocorticolimbic Circuitry. J Neurosci 2021; 41:739-750. [PMID: 33268546 PMCID: PMC7842745 DOI: 10.1523/jneurosci.1050-20.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 09/15/2020] [Accepted: 09/22/2020] [Indexed: 11/21/2022] Open
Abstract
Chronic adolescent exposure to Δ-9-tetrahydrocannabinol (THC) is linked to elevated neuropsychiatric risk and induces neuronal, molecular and behavioral abnormalities resembling neuropsychiatric endophenotypes. Previous evidence has revealed that the mesocorticolimbic circuitry, including the prefrontal cortex (PFC) and mesolimbic dopamine (DA) pathway are particularly susceptible to THC-induced pathologic alterations, including dysregulation of DAergic activity states, loss of PFC GABAergic inhibitory control and affective and cognitive abnormalities. There are currently limited pharmacological intervention strategies capable of preventing THC-induced neuropathological adaptations. l-Theanine is an amino acid analog of l-glutamate and l-glutamine derived from various plant sources, including green tea leaves. l-Theanine has previously been shown to modulate levels of GABA, DA, and glutamate in various neural regions and to possess neuroprotective properties. Using a preclinical model of adolescent THC exposure in male rats, we report that l-theanine pretreatment before adolescent THC exposure is capable of preventing long-term, THC-induced dysregulation of both PFC and VTA DAergic activity states, a neuroprotective effect that persists into adulthood. In addition, pretreatment with l-theanine blocked THC-induced downregulation of local GSK-3 (glycogen synthase kinase 3) and Akt signaling pathways directly in the PFC, two biomarkers previously associated with cannabis-related psychiatric risk and subcortical DAergic dysregulation. Finally, l-theanine powerfully blocked the development of both affective and cognitive abnormalities commonly associated with adolescent THC exposure, further demonstrating functional and long-term neuroprotective effects of l-theanine in the mesocorticolimbic system.SIGNIFICANCE STATEMENT With the increasing trend of cannabis legalization and consumption during adolescence, it is essential to expand knowledge on the potential effects of adolescent cannabis exposure on brain development and identify potential pharmacological strategies to minimize Δ-9-tetrahydrocannabinol (THC)-induced neuropathology. Previous evidence demonstrates that adolescent THC exposure induces long-lasting affective and cognitive abnormalities, mesocorticolimbic dysregulation, and schizophrenia-like molecular biomarkers that persist into adulthood. We demonstrate for the first time that l-theanine, an amino acid analog of l-glutamate and l-glutamine, is capable of preventing long-term THC side effects. l-Theanine prevented the development of THC-induced behavioral aberrations, blocked cortical downregulation of local GSK-3 (glycogen synthase kinase 3) and Akt signaling pathways, and normalized dysregulation of both PFC and VTA DAergic activity, demonstrating powerful and functional neuroprotective effects against THC-induced developmental neuropathology.
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Affiliation(s)
- Marta De Felice
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Justine Renard
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Roger Hudson
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Hanna J Szkudlarek
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Brian J Pereira
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Susanne Schmid
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Walter J Rushlow
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
- Department of Psychiatry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Steven R Laviolette
- Addiction Research Group, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
- Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
- Department of Psychiatry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 3K7, Canada
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Unno K, Furushima D, Nomura Y, Yamada H, Iguchi K, Taguchi K, Suzuki T, Ozeki M, Nakamura Y. Antidepressant Effect of Shaded White Leaf Tea Containing High Levels of Caffeine and Amino Acids. Molecules 2020; 25:molecules25153550. [PMID: 32756488 PMCID: PMC7435365 DOI: 10.3390/molecules25153550] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/21/2020] [Accepted: 07/31/2020] [Indexed: 12/19/2022] Open
Abstract
The young leaves of green tea become lighter in color than usual when protected from sunlight by a shading net for about two weeks while growing. These leaves are called "shaded white leaf tea" or SWLT. In the eluate of SWLT, the amount of amino acids (361 mg/L) was significantly higher than that in regular tea (53.5 mg/L). Since theanine and arginine, the first and second most abundant amino acids in SWLT, have significant antistress effects, we examined the antistress effect of SWLT on humans. SWLT or placebo green tea (3 g) was eluted with room-temperature water (500 mL). Participants consumed the tea for one week prior to pharmacy practice and continued for 10 days in the practice period. The state-trait anxiety inventory, an anxiety questionnaire, tended to be scored lower in the SWLT group than the placebo, but other stress markers showed no differences. The effect of the difference in SWLT components examined with mice showed that aspartic acid and asparagine, which are abundant in SWLT, counteracted the antistress effects of theanine and arginine. Large amounts of caffeine also interfered with SWLT's antistress effect. Thus, SWLT, which is high in caffeine and amino acids, suppressed depressant behavior in mice.
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Affiliation(s)
- Keiko Unno
- Tea Science Center, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan; (K.T.); (Y.N.)
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan;
- Correspondence: ; Tel.: +81-54-264-5822
| | - Daisuke Furushima
- Department of Drug Evaluation & Informatics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan; (D.F.); (Y.N.); (H.Y.)
| | - Yuzuki Nomura
- Department of Drug Evaluation & Informatics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan; (D.F.); (Y.N.); (H.Y.)
| | - Hiroshi Yamada
- Department of Drug Evaluation & Informatics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan; (D.F.); (Y.N.); (H.Y.)
| | - Kazuaki Iguchi
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan;
| | - Kyoko Taguchi
- Tea Science Center, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan; (K.T.); (Y.N.)
| | - Toshikazu Suzuki
- Tea Research Center, Shizuoka Prefectural Research Institute of Agriculture and Forestry, Kikugawa, Shizuoka 439-0002, Japan;
| | - Makoto Ozeki
- Nutrition Division, R&D Group, Taiyo Kagaku Co., Ltd., Yokkaichi, Mie 510-0844, Japan;
| | - Yoriyuki Nakamura
- Tea Science Center, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan; (K.T.); (Y.N.)
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Borgonetti V, Governa P, Biagi M, Galeotti N. Novel Therapeutic Approach for the Management of Mood Disorders: In Vivo and In Vitro Effect of a Combination of L-Theanine, Melissa officinalis L. and Magnolia officinalis Rehder & E.H. Wilson. Nutrients 2020; 12:nu12061803. [PMID: 32560413 PMCID: PMC7353338 DOI: 10.3390/nu12061803] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/19/2020] [Accepted: 06/16/2020] [Indexed: 12/14/2022] Open
Abstract
Mood disorders represent one of the most prevalent and costly psychiatric diseases worldwide. The current therapies are generally characterized by several well-known side effects which limit their prolonged use. The use of herbal medicine for the management of several psychiatric conditions is becoming more established, as it is considered a safer support to conventional pharmacotherapy. The aim of this study was to investigate the possible anxiolytic and antidepressant activity of a fixed combination of L-theanine, Magnolia officinalis, and Melissa officinalis (TMM) in an attempt to evaluate how the multiple modulations of different physiological systems may contribute to reducing mood disorders. TMM showed an anxiolytic-like and antidepressant-like activity in vivo, which was related to a neuroprotective effect in an in vitro model of excitotoxicity. The effect of TMM was not altered by the presence of flumazenil, thus suggesting a non-benzodiazepine-like mechanism of action. On the contrary, a significant reduction in the effect was observed in animals and neuronal cells co-treated with AM251, a cannabinoid receptor type 1 (CB1) antagonist, suggesting that the endocannabinoid system may be involved in the TMM mechanism of action. In conclusion, TMM may represent a useful and safe candidate for the management of mood disorders with an innovative mechanism of action, particularly as an adjuvant to conventional therapies.
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Affiliation(s)
- Vittoria Borgonetti
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology, University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy;
| | - Paolo Governa
- Department of Biotechnology, Chemistry and Pharmacy-Department of Excellence 2018-2022, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy;
| | - Marco Biagi
- Department of Physical Sciences, Earth and Environment, University of Siena, Strada Laterina 8, 53100 Siena, Italy;
| | - Nicoletta Galeotti
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology, University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy;
- Correspondence: ; Tel.: +39-055-275-8391
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Chen Y, Lian F, Lu Q, Peng S, Li J, Huang S, Du X. L-Theanine Attenuates Isoflurane-Induced Injury in Neural Stem Cells and Cognitive Impairment in Neonatal Mice. Biol Pharm Bull 2020; 43:938-945. [PMID: 32188832 DOI: 10.1248/bpb.b19-00790] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The neurodevelopmental toxicity of isoflurane has been proved by many studies, which makes it essential to explore the underline mechanisms and search for protective agents to attenuate its neurotoxcity. Accumulating evidence showed that L-theanine had neuroprotective effects on injured neurons and the developing brain. The present study was designed to investigate whether L-theanine could attenuate isoflurane-induced damage in neural stem cells and cognitive impairment in young mice, and to discuss the role of protein kinase B (Akt)-glycogen synthase kinase 3β (GSK-3β) signaling pathway in this process. Multipotential neural stem cells (NSCs) and C57BL/6J mice were treated with either gas mixture, isoflurane, or L-theanine 30 min prior to isoflurane exposure, respectively. NSC viability was detected by CCK-8 assay. NSC proliferation and apoptosis were assessed by immunofluorescence and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay, respectively. The levels of cleaved caspase-3 and phosphorylated (p)-Akt and p-GSK-3β in NSCs were tested by Western blotting. Cognitive function of mice was tested by Morris Water Maze at postnatal day (P) 30-35. The results indicated that isoflurane exposure inhibited NSC viability and proliferation, promoted NSC apoptosis as well as increased caspase-3 activation and down-regulated the expressions of p-Akt and p-GSK-3β in NSCs, and that isoflurane exposure on neonatal mice would induce late cognitive impairment. Pretreatment with L-theanine could attenuate isoflurane-caused damage in NSCs and cognitive deficits in young mice. Addinonally, the protective effects of L-theanine on isoflurane-injured NSCs could be reversed by Akt inhibitor Triciribine. Our data showed that pretreatment with L-theanine eliminated the NSC damage and cognitive impairment induced by isoflurane exposure, and that the neuroprotective effect of L-theanine was associated with the Akt-GSK-3β signaling pathway.
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Affiliation(s)
- Yong Chen
- Department of Anesthesiology, Second Affiliated Hospital of Nanchang University
| | - Fang Lian
- Department of Anesthesiology, Second Affiliated Hospital of Nanchang University
| | - Qiang Lu
- Department of Anesthesiology, Second Affiliated Hospital of Nanchang University
| | - Shengliang Peng
- Department of Anesthesiology, Second Affiliated Hospital of Nanchang University
| | - Jiahao Li
- Department of Anesthesiology, Second Affiliated Hospital of Nanchang University
| | - Song Huang
- Department of Anesthesiology, Second Affiliated Hospital of Nanchang University
| | - Xiaohong Du
- Department of Anesthesiology, Second Affiliated Hospital of Nanchang University
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18
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Williams J, McKune AJ, Georgousopoulou EN, Kellett J, D’Cunha NM, Sergi D, Mellor D, Naumovski N. The Effect of L-Theanine Incorporated in a Functional Food Product (Mango Sorbet) on Physiological Responses in Healthy Males: A Pilot Randomised Controlled Trial. Foods 2020; 9:foods9030371. [PMID: 32210015 PMCID: PMC7142516 DOI: 10.3390/foods9030371] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/18/2020] [Accepted: 03/18/2020] [Indexed: 12/21/2022] Open
Abstract
Consumption of L-Theanine (L-THE) has been associated with a sensation of relaxation, as well as a reduction of stress. However, these physiological responses have yet to be elucidated in humans where L-THE is compared alongside food or as a functional ingredient within the food matrix. The aim of this study was to determine the physiological responses of a single intake of a potential functional food product (mango sorbet) containing L-THE (ms-L-THE; 200 mgw/w) in comparison to a flavour and colour-matched placebo (ms). Eighteen healthy male participants were recruited in this randomised, double-blind, placebo-controlled trial. The participants were required to consume ms-L-THE or placebo and their blood pressure (BP) (systolic and diastolic), heart rate (HR), and heart rate variability (HRV) were monitored continuously over 90 minutes. Eleven males (age 27.7 ± 10.8 years) completed the study. Changes in area under the curve for systolic and diastolic blood pressure and HRV over the 90 minute observation period indicated no differences between the three conditions (all p > 0.05) or within individual groups (all p > 0.05). The values for heart rate were also not different in the placebo group (p = 0.996) and treatment group (p = 0.066), while there was a difference seen at the baseline (p = 0.003). Based on the findings of this study, L-THE incorporated in a food matrix (mango sorbet) demonstrated no reduction in BP or HR and showed no significant parasympathetic interaction as determined by HRV high-frequency band and low-frequency/high-frequency ratio. Further studies should be focussed towards the comparison of pure L-THE and incorporation within the food matrix to warrant recommendations of L-THE alongside food consumption.
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Affiliation(s)
- Jackson Williams
- Faculty of Health, University of Canberra, Canberra, ACT 2601, Australia; (J.W.); (A.J.M.); (J.K.); (N.M.D.)
| | - Andrew J. McKune
- Faculty of Health, University of Canberra, Canberra, ACT 2601, Australia; (J.W.); (A.J.M.); (J.K.); (N.M.D.)
- Discipline of Biokinetics, Exercise and Leisure Sciences, School of Health Sciences, University of KwaZulu-Natal, Durban, KwaZulu-Natal 4000, South Africa
- Research Institute of Sport and Exercise, University of Canberra, Canberra, ACT 2605, Australia
| | - Ekavi N. Georgousopoulou
- Centre for Health and Medical Research, ACT Health Directorate, Canberra, ACT 2601, Australia;
- Medical School, Australian National University, Canberra, ACT 2601, Australia
- School of Medicine, University of Notre Dame Australia, Sydney, NSW 2000, Australia
| | - Jane Kellett
- Faculty of Health, University of Canberra, Canberra, ACT 2601, Australia; (J.W.); (A.J.M.); (J.K.); (N.M.D.)
| | - Nathan M. D’Cunha
- Faculty of Health, University of Canberra, Canberra, ACT 2601, Australia; (J.W.); (A.J.M.); (J.K.); (N.M.D.)
| | - Domenico Sergi
- Nutrition & Health Substantiation Group, Nutrition and Health Program, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Adelaide, SA 5000, Australia;
| | - Duane Mellor
- Aston Medical School, Aston University, Birmingham B47ET, UK;
| | - Nenad Naumovski
- Faculty of Health, University of Canberra, Canberra, ACT 2601, Australia; (J.W.); (A.J.M.); (J.K.); (N.M.D.)
- Correspondence:
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Selective Upregulation by Theanine of Slc38a1 Expression in Neural Stem Cell for Brain Wellness. Molecules 2020; 25:molecules25020347. [PMID: 31952134 PMCID: PMC7024158 DOI: 10.3390/molecules25020347] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/09/2020] [Accepted: 01/15/2020] [Indexed: 12/22/2022] Open
Abstract
Theanine is an amino acid abundant in green tea with an amide moiety analogous to glutamine (GLN) rather than glutamic acid (Glu) and GABA, which are both well-known as amino acid neurotransmitters in the brain. Theanine has no polyphenol and flavonoid structures required for an anti-oxidative property as seen with catechins and tannins, which are more enriched in green tea. We have shown marked inhibition by this exogenous amino acid theanine of the uptake of [3H]GLN, but not of [3H]Glu, in rat brain synaptosomes. Beside a ubiquitous role as an endogenous amino acid, GLN has been believed to be a main precursor for the neurotransmitter Glu sequestered in a neurotransmitter pool at glutamatergic neurons in the brain. The GLN transporter solute carrier 38a1 (Slc38a1) plays a crucial role in the incorporation of extracellular GLN for the intracellular conversion to Glu by glutaminase and subsequent sequestration at synaptic vesicles in neurons. However, Slc38a1 is also expressed by undifferentiated neural progenitor cells (NPCs) not featuring a neuronal phenotype. NPCs are derived from a primitive stem cell endowed to proliferate for self-renewal and to commit differentiation to several daughter cell lineages such as neurons, astrocytes, and oligodendrocytes. In vitro culture with theanine leads to the marked promotion of the generation of new neurons together with selective upregulation of Slc38a1 transcript expression in NPCs. In this review, we will refer to a possible novel neurogenic role of theanine for brain wellness through a molecular mechanism relevant to facilitated neurogenesis with a focus on Slc38a1 expressed by undifferentiated NPCs on the basis of our accumulating findings to date.
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Solute carrier transporters: the metabolic gatekeepers of immune cells. Acta Pharm Sin B 2020; 10:61-78. [PMID: 31993307 PMCID: PMC6977534 DOI: 10.1016/j.apsb.2019.12.006] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/29/2019] [Accepted: 10/31/2019] [Indexed: 02/06/2023] Open
Abstract
Solute carrier (SLC) transporters meditate many essential physiological functions, including nutrient uptake, ion influx/efflux, and waste disposal. In its protective role against tumors and infections, the mammalian immune system coordinates complex signals to support the proliferation, differentiation, and effector function of individual cell subsets. Recent research in this area has yielded surprising findings on the roles of solute carrier transporters, which were discovered to regulate lymphocyte signaling and control their differentiation, function, and fate by modulating diverse metabolic pathways and balanced levels of different metabolites. In this review, we present current information mainly on glucose transporters, amino-acid transporters, and metal ion transporters, which are critically important for mediating immune cell homeostasis in many different pathological conditions.
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Key Words
- 3-PG, 3-phosphoglyceric acid
- ABC, ATP-binding cassette
- AIF, apoptosis-inducing factor
- AP-1, activator protein 1
- ASCT2, alanine serine and cysteine transporter system 2
- ATP, adenosine triphosphate
- BCR, B cell receptor
- BMDMs, bone marrow-derived macrophages
- CD45R, a receptor-type protein tyrosine phosphatase
- CTL, cytotoxic T lymphocytes
- DC, dendritic cells
- EAATs, excitatory amino acid transporters
- ER, endoplasmic reticulum
- ERRα, estrogen related receptor alpha
- FFA, free fatty acids
- G-6-P, glucose 6-phosphate
- GLUT, glucose transporters
- GSH, glutathione
- Glucose
- Glutamine
- HIF-1α, hypoxia-inducible factor 1-alpha
- HIV-1, human immunodeficiency virus type 1
- Hk1, hexokinase-1
- IFNβ, interferon beta
- IFNγ, interferon gamma
- IKK, IκB kinase
- IKKβ, IκB kinase beta subunit
- IL, interleukin
- LDHA, lactate dehydrogenase A
- LPS, lipopolysaccharide
- Lymphocytes
- Lyn, tyrosine-protein kinase
- MAPK, mitogen-activated protein kinase
- MCT, monocarboxylate transporters
- MS, multiple sclerosis
- Metal ion
- NADPH, nicotinamide adenine dinucleotide phosphate
- NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells
- NO, nitric oxide
- NOD2, nucleotide-binding oligomerization domain containing 2
- PEG2, prostaglandin E2
- PI-3K/AKT, phosphatidylinositol-3-OH kinase/serine–threonine kinase
- PPP, pentose phosphate pathway
- Pfk, phosphofructokinase
- RA, rheumatoid arthritis
- RLR, RIG-I-like receptor
- ROS, reactive oxygen species
- SLC, solute carrier
- SLE, systemic lupus erythematosus
- SNAT, sodium-coupled neutral amino acid transporters
- STAT, signal transducers and activators of transcription
- Solute carrier
- TAMs, tumor-associated macrophages
- TCA, tricarboxylic acid
- TCR, T cell receptor
- TLR, toll-like receptor
- TNF, tumor necrosis factor
- TRPM7, transient receptor potential cation channel subfamily M member 7
- Teffs, effector T cells
- Th1/2/17, type 1/2/17 helper T cells
- Tregs, regulatory T cells
- VEGF, vascular endothelial growth factor
- ZIP, zrt/irt-like proteins
- iNOS, inducible nitric oxide synthase
- iTregs, induced regulatory T cells
- mTORC1, mammalian target of rapamycin complex 1
- α-KG, α-ketoglutaric acid
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Modifiable risk and protective factors in disease development, progression and clinical subtypes of Parkinson's disease: What do prospective studies suggest? Neurobiol Dis 2019; 134:104671. [PMID: 31706021 DOI: 10.1016/j.nbd.2019.104671] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 10/23/2019] [Accepted: 11/05/2019] [Indexed: 12/20/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder whose pathogenesis depends on a combination of genetic and environmental factors. The aim of the present review was to provide an updated description of the findings emerging from prospective longitudinal cohort studies on the possible risk/protective factors underlying the development, progression and clinical subtypes of PD. We reviewed all the environmental, lifestyle, dietary, comorbid and pharmacological factors that have been investigated as possible modifiable protective/risk factors for PD by longitudinal studies. Only a few factors have the epidemiological evidence and the biological plausibility to be considered risk (pesticides, dairy products, β2-adrenoreceptor antagonists) or protective (smoking, caffeine and tea intake, physical activity, gout, vitamin E intake, non-steroidal anti-inflammatory drugs and β2-adrenoreceptor agonists) factors for PD. Caffeine intake and physical activity also seem to slow down the progression of the disease, thus representing good candidates for primary prevention and disease modifying strategies in PD. Possible modifiable risk factors of PD subtypes is almost unknown and this might depend on the uncertain biological and neuropathological reliability of clinical subtypes. The results of the present review suggest that only eleven risk/protective factors may be associated with the risk of PD. It may be possible to target some of these factors for preventive interventions aimed at reducing the risk of developing and the rate of progression of PD.
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Deb S, Dutta A, Phukan BC, Manivasagam T, Justin Thenmozhi A, Bhattacharya P, Paul R, Borah A. Neuroprotective attributes of L-theanine, a bioactive amino acid of tea, and its potential role in Parkinson's disease therapeutics. Neurochem Int 2019; 129:104478. [DOI: 10.1016/j.neuint.2019.104478] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 05/17/2019] [Accepted: 05/26/2019] [Indexed: 10/26/2022]
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Lopes Sakamoto F, Metzker Pereira Ribeiro R, Amador Bueno A, Oliveira Santos H. Psychotropic effects of L-theanine and its clinical properties: From the management of anxiety and stress to a potential use in schizophrenia. Pharmacol Res 2019; 147:104395. [PMID: 31412272 DOI: 10.1016/j.phrs.2019.104395] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/07/2019] [Accepted: 08/08/2019] [Indexed: 12/12/2022]
Abstract
Anxiety disorders are highly prevalent in modern societies, and are ranked the sixth most important contributor of non-fatal negative health outcomes. L-theanine is an amino acid naturally found in green tea (Camellia sinensis) and some other plant extracts, and recent clinical studies have proposed promising adjuvant effects of L-theanine for the negative impact of anxiety and psychological stress on health. In this integrative narrative review, we aimed to appraise and further discuss the effects of L-theanine administration on anxiety disorders and psychological stress. Published data suggests that L-theanine administered at daily doses ranging from 200 to 400 mg for up to 8 weeks are safe and induce anxiolytic and anti-stress effects in acute and chronic conditions. L-theanine at doses lower and higher than these may also show promising therapeutic potential; however, a more thorough investigation through randomized double-blind placebo-controlled crossover clinical trials are necessary to elucidate its effects for longer periods, providing further insights for meta-analyses and the development of recommendation guidelines. Additionally, animal studies investigating a higher dosage, its combination with other pharmacological compounds and associated metabolic comorbidities are recommended, as cases of hepatotoxicity associated with the consumption of green tea extract have been reported.
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Affiliation(s)
| | | | - Allain Amador Bueno
- College of Health, Life and Environmental Sciences, University of Worcester, United Kingdom
| | - Heitor Oliveira Santos
- School of Medicine, Federal University of Uberlândia (UFU), Uberlandia, Minas Gerais, Brazil.
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Yoneda Y, Kuramoto N, Kawada K. The role of glutamine in neurogenesis promoted by the green tea amino acid theanine in neural progenitor cells for brain health. Neurochem Int 2019; 129:104505. [PMID: 31310779 DOI: 10.1016/j.neuint.2019.104505] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 12/15/2022]
Abstract
The green tea amino acid theanine is abundant in green tea rather than black and oolong teas, which are all made of the identical tea plant "Chanoki" (Camellia sinensis). Theanine has a molecular structure close to glutamine (GLN) compared to glutamic acid (Glu), in terms of the absence of a free carboxylic acid moiety from the gamma carbon position. Theanine efficiently inhibits [3H]GLN uptake without affecting [3H]Glu uptake in rat brain synaptosomes. In contrast to GLN, however, theanine markedly stimulates the abilities to replicate and to commit to a neuronal lineage following prolonged exposure in cultured neural progenitor cells (NPCs) prepared from embryonic and adult rodent brains. Upregulation of transcript expression is found for one of the GLN transporter isoforms, Slc38a1, besides the promotion of both proliferation and neuronal commitment along with acceleration of the phosphorylation of mechanistic target of rapamycin (mTOR) and relevant downstream proteins, in murine NPCs cultured with theanine. Stable overexpression of Slc38a1 similarly facilitates both cellular replication and neuronal commitment in pluripotent embryonic carcinoma P19 cells. In P19 cells with stable overexpression of Slc38a1, marked phosphorylation is seen for mTOR and downstream proteins in a manner insensitive to further additional phosphorylation by theanine. Taken together, theanine would exhibit a novel pharmacological property to up-regulate Slc38a1 expression for activation of the intracellular mTOR signaling pathway required for neurogenesis after sustained exposure in undifferentiated NPCs in the brain. In this review, a novel neurogenic property of the green tea amino acid theanine is summarized for embryonic and adult neurogenesis with a focus on the endogenous amino acid GLN on the basis of our accumulating evidence to date.
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Affiliation(s)
- Yukio Yoneda
- Department of Pharmacology, Osaka University Graduate School of Dentistry, Suita, 565-0871, Japan; The Institute of Prophylactic Pharmacology, Kita-Shinagawa, Shinagawa, 140-0001, Tokyo, Japan.
| | - Nobuyuki Kuramoto
- The Institute of Prophylactic Pharmacology, Kita-Shinagawa, Shinagawa, 140-0001, Tokyo, Japan; Laboratory of Molecular Pharmacology, Setsunan University Faculty of Pharmaceutical Sciences, Hirakata, 573-0101, Japan
| | - Koichi Kawada
- The Institute of Prophylactic Pharmacology, Kita-Shinagawa, Shinagawa, 140-0001, Tokyo, Japan; Department of Pharmacology, Chiba Institute of Science Faculty of Pharmaceutical Sciences, Chiba, 288-0025, Japan
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Katasonov AB. [Neurobiological effects of theanine and its possible use in neurology and psychiatry]. Zh Nevrol Psikhiatr Im S S Korsakova 2019; 118:118-124. [PMID: 30585616 DOI: 10.17116/jnevro2018118111118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Theanine is an analog of glutamate and the major aminoacid in green tea. It has received growing attention in recent years because of its beneficial effects on the central nervous system. Theanine was shown to increase levels of brain-derived neurotrophic factor and to stimulate neurogenesis. Anti-stress and calming effects of theanine are the most apparent and well-studied. A number of studies showed neuroprotective effects of theanine after an ischemic cerebral injury or the exposure to toxic chemicals. It also improved cognitive function including attention, memory and learning. Recent studies demonstrated a promising role of theanine in augmentation therapy for major depressive disorder and schizophrenia. Theoretical grounds for using theanine in treatment of bipolar disorder, anxiety disorder and some neurodegenerative disorders are discussed.
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Unno K, Furushima D, Hamamoto S, Iguchi K, Yamada H, Morita A, Pervin M, Nakamura Y. Stress-reducing effect of cookies containing matcha green tea: essential ratio among theanine, arginine, caffeine and epigallocatechin gallate. Heliyon 2019; 5:e01653. [PMID: 31111111 PMCID: PMC6512570 DOI: 10.1016/j.heliyon.2019.e01653] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 04/09/2019] [Accepted: 05/01/2019] [Indexed: 12/31/2022] Open
Abstract
The stress-reducing effect of matcha, a high-quality fine-powdered green tea, has recently been clarified by animal experiments and clinical trials. However, the effect of matcha added to confectioneries is not clear. One aim of this study was to evaluate the relationship between matcha components and their stress-reducing effect in mice that were loaded with territorially-based stress. Adrenal hypertrophy, a marker of stress, was significantly suppressed in stress-loaded mice that had ingested matcha components, displaying a caffeine and epigallocatechin gallate to theanine and arginine (CE/TA) ratio of 2 or less. Another aim was to evaluate, in humans, the stress-reducing effect of matcha in cookies using test-matcha (CE/TA = 1.79) or placebo-matcha (CE/TA = 10.64). Participants, who were fifth year pharmacy college students, consumed 4.5 g of matcha in three pieces of cookie daily for 15 days. Salivary α-amylase activity, a stress marker, was significantly lower in the test-matcha group than in the placebo group. These results indicate that the CE/TA ratio of tea components is a key indicator for the suppression of stress. Moreover, matcha with a CE/TA ratio of 2 or less displays a stress-reducing effect, even if it is included in confectionery products. Such products may also benefit individuals who have no habit of drinking matcha as a beverage.
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Affiliation(s)
- Keiko Unno
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan.,Tea Science Center, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Daisuke Furushima
- Department of Drug Evaluation & Informatics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Shingo Hamamoto
- Department of Drug Evaluation & Informatics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Kazuaki Iguchi
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Hiroshi Yamada
- Department of Drug Evaluation & Informatics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Akio Morita
- Department of Functional Plant Physiology, Faculty of Agriculture, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Monira Pervin
- Tea Science Center, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
| | - Yoriyuki Nakamura
- Tea Science Center, Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, 422-8526, Japan
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L-theanine in the adjunctive treatment of generalized anxiety disorder: A double-blind, randomised, placebo-controlled trial. J Psychiatr Res 2019; 110:31-37. [PMID: 30580081 DOI: 10.1016/j.jpsychires.2018.12.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 12/06/2018] [Accepted: 12/07/2018] [Indexed: 01/21/2023]
Abstract
Partial or non-response to antidepressants in Generalized Anxiety Disorder (GAD) is common in clinical settings, and adjunctive biological interventions may be required. Adjunctive herbal and nutraceutical treatments are a novel and promising treatment option. L-theanine is a non-protein amino acid derived most-commonly from tea (Camellia sinensis) leaves, which may be beneficial in the treatment of anxiety and sleep disturbance as suggested by preliminary evidence. We conducted a 10-week study (consisting of an 8-week double-blind placebo-controlled period, and 1-week pre-study and 2-week post-study single-blinded observational periods) involving 46 participants with a DSM-5 diagnosis of GAD. Participants received adjunctive L-theanine (450-900 mg) or matching placebo with their current stable antidepressant treatment, and were assessed on anxiety, sleep quality, and cognition outcomes. Results revealed that adjunctive L-theanine did not outperform placebo for anxiety reduction on the HAMA (p = 0.73) nor insomnia severity on the Insomnia Severity Index (ISI; p = 0.35). However, LT treated participants reported greater self-reported sleep satisfaction than placebo (ISI item 4; p = 0.015). Further, a separation in favour of L-theanine was noted on the ISI in those with non-clinical levels of insomnia symptoms (ISI ≤ 14; p = 0.007). No significant cognitive effects (trail making time and the modified emotional Stroop) were revealed. While this preliminary study did not support the efficacy of L-theanine in the treatment of anxiety symptoms in GAD, further studies to explore the application of L-theanine in sleep disturbance are warranted.
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Altınkaynak Y, Kural B, Akcan BA, Bodur A, Özer S, Yuluğ E, Munğan S, Kaya C, Örem A. Protective effects of L-theanine against doxorubicin-induced nephrotoxicity in rats. Biomed Pharmacother 2018; 108:1524-1534. [DOI: 10.1016/j.biopha.2018.09.171] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 09/28/2018] [Accepted: 09/28/2018] [Indexed: 12/20/2022] Open
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Xin Y, Ben P, Wang Q, Zhu Y, Yin Z, Luo L. Theanine, an antitumor promoter, induces apoptosis of tumor cells via the mitochondrial pathway. Mol Med Rep 2018; 18:4535-4542. [PMID: 30221698 DOI: 10.3892/mmr.2018.9459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 03/28/2017] [Indexed: 11/06/2022] Open
Abstract
Theanine, an active component of green tea (Camellia sinensis), is considered a modulator of chemotherapy. To further investigate the anticancer activity of theanine, the present study investigated the cytotoxic effect of theanine at the concentration of 600 µg/ml, in the human HepG2 hepatoblastoma and HeLa adenocarcinoma cell lines, in comparison with the normal L02, H9c2 and HEK293 cell lines using a MTT assay. It was found that theanine induced cell death in the tumor cells, but not in the normal cells. Notably, when glutamine was restricted or reduced in the cell culture medium, the cell death induced by theanine was significantly enhanced. A terminal deoxynucleotidyl‑transferase‑mediated dUTP nick end labeling assay indicated that DNA damage was induced in theanine‑treated HepG2 cells. Further experiments demonstrated that theanine caused HepG2 cell apoptosis through the mitochondrial pathway, with a loss of membrane potential and the release of apoptosis‑inducing factor, endonuclease G and cytochrome c. Western blot analysis and caspase activity detection also revealed that caspase‑9 and caspase‑3 were activated, whereas caspase‑8 remained inactive. These observations suggested that theanine exerted potent cytotoxicity on tumor cells when glutamine was restricted.
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Affiliation(s)
- Yinqiang Xin
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Peiling Ben
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Qi Wang
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Yanyan Zhu
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Zhimin Yin
- Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, P.R. China
| | - Lan Luo
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, P.R. China
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Theanine supplementation prevents liver injury and heat shock response by normalizing hypothalamic-pituitaryadrenal axis hyperactivity in mice subjected to whole body heat stress. J Funct Foods 2018. [DOI: 10.1016/j.jff.2018.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Dietz C, Dekker M. Effect of Green Tea Phytochemicals on Mood and Cognition. Curr Pharm Des 2018; 23:2876-2905. [PMID: 28056735 DOI: 10.2174/1381612823666170105151800] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/01/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Green tea is traditionally known to induce mental clarity, cognitive function, physical activation and relaxation. Recently, a special green tea, matcha tea, is rapidly gaining popularity throughout the world and is frequently referred to as a mood- and brain food. Matcha tea consumption leads to much higher intake of green tea phytochemicals compared to regular green tea. Previous research on tea constituents caffeine, L-theanine, and epigallocatechin gallate (EGCG) repeatedly demonstrated benefits on mood and cognitive performance. These effects were observed when these phytochemicals were consumed separately and in combination. METHODS A review was conducted on 49 human intervention studies to summarize the research on acute psychoactive effects of caffeine, L-theanine, and EGCG on different dimensions of mood and cognitive performance. CONCLUSION Caffeine was found to mainly improve performance on demanding long-duration cognitive tasks and self-reported alertness, arousal, and vigor. Significant effects already occurred at low doses of 40 mg. L-theanine alone improved self-reported relaxation, tension, and calmness starting at 200 mg. L-theanine and caffeine combined were found to particularly improve performance in attention-switching tasks and alertness, but to a lesser extent than caffeine alone. No conclusive evidence relating to effects induced by EGCG could be given since the amount of intervention studies was limited. These studies provided reliable evidence showing that L-theanine and caffeine have clear beneficial effects on sustained attention, memory, and suppression of distraction. Moreover, L-theanine was found to lead to relaxation by reducing caffeine induced arousal.
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Affiliation(s)
- Christina Dietz
- Food Quality and Design Group, Wageningen University, Wageningen, Netherlands
| | - Matthijs Dekker
- Food Quality and Design Group, Wageningen University, Wageningen, Netherlands
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Unno K, Yamada H, Iguchi K, Ishida H, Iwao Y, Morita A, Nakamura Y. Anti-stress Effect of Green Tea with Lowered Caffeine on Humans: A Pilot Study. Biol Pharm Bull 2018; 40:902-909. [PMID: 28566632 DOI: 10.1248/bpb.b17-00141] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the effect of theanine was blocked by caffeine and gallate-type catechins, which are the main components in tea. We examined the anti-stress effect of green tea with lowered caffeine, low-caffeine green tea, on humans. The study design was a single-blind group comparison and participants (n=20) were randomly assigned to low-caffeine or placebo tea groups. These teas (≥500 mL/d), which were eluted with room temperature water, were taken from 1 week prior to pharmacy practice and continued for 10 d in the practice period. The participants ingested theanine (ca. 15 mg/d) in low-caffeine green tea. To assess the anxiety of participants, the state-trait anxiety inventory test was used before pharmacy practice. The subjective stress of students was significantly lower in the low-caffeine-group than in the placebo-group during pharmacy practice. The level of salivary α-amylase activity, a stress marker, increased significantly after daily pharmacy practice in the placebo-group but not in the low-caffeine-group. These results suggested that the ingestion of low-caffeine green tea suppressed the excessive stress response of students. This study was registered at the University Hospital Medical Information Network (ID No. UMIN14942).
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Affiliation(s)
- Keiko Unno
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka.,Tea Science Center, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka
| | - Hiroshi Yamada
- Division of Drug Evaluation & Informatics, School of Pharmaceutical Sciences, University of Shizuoka
| | - Kazuaki Iguchi
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Hitoshi Ishida
- Medicinal Chemistry of Natural Products, School of Pharmaceutical Sciences, University of Shizuoka
| | - Yasunori Iwao
- Pharmaceutical Engineering Laboratory, School of Pharmaceutical Sciences, University of Shizuoka
| | - Akio Morita
- Department of Functional Plant Physiology, Faculty of Agriculture, Shizuoka University
| | - Yoriyuki Nakamura
- Tea Science Center, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka
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Chen SQ, Wang ZS, Ma YX, Zhang W, Lu JL, Liang YR, Zheng XQ. Neuroprotective Effects and Mechanisms of Tea Bioactive Components in Neurodegenerative Diseases. Molecules 2018; 23:E512. [PMID: 29495349 PMCID: PMC6017384 DOI: 10.3390/molecules23030512] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 02/23/2018] [Accepted: 02/23/2018] [Indexed: 12/19/2022] Open
Abstract
As the population ages, neurodegenerative diseases such as Parkinson's disease (PD) and Alzheimer's disease (AD) impose a heavy burden on society and families. The pathogeneses of PD and AD are complex. There are no radical cures for the diseases, and existing therapeutic agents for PD and AD have diverse side effects. Tea contains many bioactive components such as polyphenols, theanine, caffeine, and theaflavins. Some investigations of epidemiology have demonstrated that drinking tea can decrease the risk of PD and AD. Tea polyphenols can lower the morbidity of PD and AD by reducing oxidative stress and regulating signaling pathways and metal chelation. Theanine can inhibit the glutamate receptors and regulate the extracellular concentration of glutamine, presenting neuroprotective effects. Additionally, the neuroprotective mechanisms of caffeine and theaflavins may contribute to the ability to antagonize the adenosine receptor A2AR and the antioxidant properties, respectively. Thus, tea bioactive components might be useful for neuronal degeneration treatment in the future. In the present paper, the neuro protection and the mechanisms of tea and its bioactive components are reviewed. Moreover, the potential challenges and future work are also discussed.
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Affiliation(s)
- Shu-Qing Chen
- Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
| | - Ze-Shi Wang
- Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
| | - Yi-Xiao Ma
- Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
| | - Wei Zhang
- Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
| | - Jian-Liang Lu
- Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
| | - Yue-Rong Liang
- Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
| | - Xin-Qiang Zheng
- Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
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Effects of L-theanine on anxiety-like behavior, cerebrospinal fluid amino acid profile, and hippocampal activity in Wistar Kyoto rats. Psychopharmacology (Berl) 2018; 235:37-45. [PMID: 28971241 DOI: 10.1007/s00213-017-4743-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/16/2017] [Accepted: 09/11/2017] [Indexed: 12/11/2022]
Abstract
RATIONALE AND OBJECTIVES The amino acid L-theanine (N-ethyl-L-glutamine) has historically been considered a relaxing agent. In the present study, we examined the effects of repeated L-theanine administration on behavior, levels of amino acids in the cerebrospinal fluid (CSF), and hippocampal activity in Wistar Kyoto (WKY) rats, an animal model of anxiety and depressive disorders. METHODS Behavioral tests were performed after 7-10 days of L-theanine (0.4 mg kg-1 day-1) or saline administration, followed by CSF sampling for high-performance liquid chromatography (HPLC) analysis. An independent set of animals was subjected to [18F]fluorodeoxyglucose positron emission tomography (PET) scanning after the same dose of L-theanine or saline administration for 7 days. RESULTS In the elevated plus maze test, the time spent in the open arms was significantly longer in the L-theanine group than in the saline group (P = 0.035). In addition, significantly lower CSF glutamate (P = 0.039) and higher methionine (P = 0.024) concentrations were observed in the L-theanine group than in the saline group. A significant increase in the standard uptake value ratio was observed in the hippocampus/cerebellum of the L-theanine group (P < 0.001). CONCLUSIONS These results suggest that L-theanine enhances hippocampal activity and exerts anxiolytic effects, which may be mediated by changes in glutamate and methionine levels in the brain. Further study is required to more fully elucidate the mechanisms underlying the effects of L-theanine.
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Sharma E, Joshi R, Gulati A. l-Theanine: An astounding sui generis integrant in tea. Food Chem 2017; 242:601-610. [PMID: 29037735 DOI: 10.1016/j.foodchem.2017.09.046] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 09/06/2017] [Accepted: 09/11/2017] [Indexed: 11/30/2022]
Abstract
l-theanine (l-Th), a non-protein amino acid present in tea, is a valuable nutraceutical product with unique health benefits and used as an additive in food industry. l-Th enhances the umami taste but its use is limited due to its inadequate production. Different extraction approaches from tea shoots, chemical synthesis to microbial transformation have been tried to meet its demand. In vitro, in vivo as well as clinical studies have shown its positive effect in regulating CNS disorders. l-Th has become choice ingredient in CNS active products due to its anti-stress and neuroprotective role in dementias particularly in retrogression of Alzheimer's. l-Th biochemically modulates various anti-neoplastic agents by increasing their bioavailability in tumour cells. The review, is an effort to condense the recent research on l-Th highlighting its biological resource, plausible role in tea plant, production approaches, its physiological role on human health and future prospects.
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Affiliation(s)
- Eshita Sharma
- CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India; Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Robin Joshi
- CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India
| | - Ashu Gulati
- CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, India.
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L-Theanine Administration Modulates the Absorption of Dietary Nutrients and Expression of Transporters and Receptors in the Intestinal Mucosa of Rats. BIOMED RESEARCH INTERNATIONAL 2017; 2017:9747256. [PMID: 28812027 PMCID: PMC5546063 DOI: 10.1155/2017/9747256] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 06/03/2017] [Accepted: 06/15/2017] [Indexed: 01/22/2023]
Abstract
L-theanine has various advantageous functions for human health; whether or not it could mediate the nutrients absorption is unknown yet. The effects of L-theanine on intestinal nutrients absorption were investigated using rats ingesting L-theanine solution (0, 50, 200, and 400 mg/kg body weight) per day for two weeks. The decline of insulin secretion and glucose concentration in the serum was observed by L-theanine. Urea and high-density lipoprotein were also reduced by 50 mg/kg L-theanine. Jejunal and ileac basic amino acids transporters SLC7a1 and SLC7a9, neutral SLC1a5 and SLC16a10, and acidic SLC1a1 expression were upregulated. The expression of intestinal SGLT3 and GLUT5 responsible for carbohydrates uptake and GPR120 and FABP2 associated with fatty acids transport were inhibited. These results indicated that L-theanine could inhibit the glucose uptake by downregulating the related gene expression in the small intestine of rats. Intestinal gene expression of transporters responding to amino acids absorption was stimulated by L-theanine administration.
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An l-Glutamine Transporter Isoform for Neurogenesis Facilitated by l-Theanine. Neurochem Res 2017; 42:2686-2697. [DOI: 10.1007/s11064-017-2317-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 05/25/2017] [Accepted: 05/29/2017] [Indexed: 12/14/2022]
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Unno K, Hara A, Nakagawa A, Iguchi K, Ohshio M, Morita A, Nakamura Y. Anti-stress effects of drinking green tea with lowered caffeine and enriched theanine, epigallocatechin and arginine on psychosocial stress induced adrenal hypertrophy in mice. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2016; 23:1365-1374. [PMID: 27765356 DOI: 10.1016/j.phymed.2016.07.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 07/13/2016] [Accepted: 07/19/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the anti-stress effects of drinking green tea have not yet been elucidated. HYPOTHESIS/PURPOSE The present study aimed to explore anti-stress effects of green tea and roles of tea components in a mouse model of psychosocial stress. STUDY DESIGN We examined anti-stress effects of three types of green teas, theanine-rich "Gyokuro", standard "Sencha", and Sencha with lowered caffeine (low-caffeine green tea). Furthermore, the roles of tea components such as caffeine, catechins, and other amino acids in anti-stress effects were examined. METHODS To prepare low-caffeine green tea, plucked new tea leaves were treated with a hot-water spray. Mice were psychosocially stressed from a conflict among male mice under confrontational housing. Mice consumed each tea that was eluted with room temperature water ad libitum. As a marker for the stress response, adrenal hypertrophy was compared with mice that ingested water. RESULTS Caffeine was significantly lowered by spraying hot-water on tea leaves. While epigallocatechin gallate (EGCG) is the main catechin in tea leaves, epigallocatechin (EGC) was mainly infused into water at room temperature. Adrenal hypertrophy was significantly suppressed in mice that ingested theanine-rich and low-caffeine green tea that were eluted with water at room temperature. Caffeine and EGCG suppressed the anti-stress effects of theanine while EGC and arginine (Arg) retained these effects. CONCLUSION These results suggest that drinking green tea exhibits anti-stress effects, where theanine, EGC and Arg cooperatively abolish the counter-effect of caffeine and EGCG on psychosocial stress induced adrenal hypertrophy in mice.
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Affiliation(s)
- Keiko Unno
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan; Tea Science Center, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
| | - Ayane Hara
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Aimi Nakagawa
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Kazuaki Iguchi
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| | - Megumi Ohshio
- Department of Functional Plant Physiology, Faculty of Agriculture, Shizuoka University, Shizuoka, Japan
| | - Akio Morita
- Department of Functional Plant Physiology, Faculty of Agriculture, Shizuoka University, Shizuoka, Japan
| | - Yoriyuki Nakamura
- Tea Science Center, Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan
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Bae D, Kim J, Oh DR, Kim Y, Choi EJ, Lee H, Jung MA, Lee SY, Jeong C, Lee M, Kang N, Lee J, Kim S. Multifunctional antistress effects of standardized aqueous extracts from Hippophae rhamnoides L. Anim Cells Syst (Seoul) 2016. [DOI: 10.1080/19768354.2016.1250816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Takeshima M, Miyazaki I, Murakami S, Kita T, Asanuma M. l-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes. J Clin Biochem Nutr 2016. [PMID: 27698535 DOI: 10.3164/jcbn.16.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
l-Theanine (γ-glutamylethylamide), a component of green tea, is considered to have regulatory and neuroprotective roles in the brain. The present study was designed to determine the effect of l-theanine on excess dopamine-induced neurotoxicity in both cell culture and animal experiments. The primary cultured mesencephalic neurons or co-cultures of mesencephalic neurons and striatal astrocytes were pretreated with l-theanine for 72 h, and then treated with excess dopamine for further 24 h. The cell viability of dopamine neurons and levels of glutathione were evaluated. Excess dopamine-induced neurotoxicity was significantly attenuated by 72 h preincubation with l-theanine in neuron-astrocyte co-cultures but not in neuron-rich cultures. Exposure to l-theanine increased the levels of glutathione in both astrocytes and glial conditioned medium. The glial conditioned medium from l-theanine-pretreated striatal astrocytes attenuated dopamine-induced neurotoxicity and quinoprotein formation in mesencephalic neurons. In addition, replacement of l-glutamate with l-theanine in an in vitro cell-free glutathione-synthesis system produced glutathione-like thiol compounds. Furthermore, l-theanine administration (4 mg/kg, p.o.) for 14 days significantly increased glutathione levels in the striatum of mice. The results suggest that l-theanine provides neuroprotection against oxidative stress-induced neuronal damage by humoral molecules released from astrocytes, probably including glutathione.
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Affiliation(s)
- Mika Takeshima
- Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Ikuko Miyazaki
- Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Shinki Murakami
- Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; SAIDO Co., Fukuoka 810-0021, Japan
| | - Taizo Kita
- Laboratory of Pharmacology, Kyushu Nutrition Welfare University School of Health Science, Fukuoka 803-8511, Japan
| | - Masato Asanuma
- Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
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Takeshima M, Miyazaki I, Murakami S, Kita T, Asanuma M. l-Theanine protects against excess dopamine-induced neurotoxicity in the presence of astrocytes. J Clin Biochem Nutr 2016; 59:93-99. [PMID: 27698535 PMCID: PMC5018574 DOI: 10.3164/jcbn.16-15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 04/12/2016] [Indexed: 01/05/2023] Open
Abstract
l-Theanine (γ-glutamylethylamide), a component of green tea, is considered to have regulatory and neuroprotective roles in the brain. The present study was designed to determine the effect of l-theanine on excess dopamine-induced neurotoxicity in both cell culture and animal experiments. The primary cultured mesencephalic neurons or co-cultures of mesencephalic neurons and striatal astrocytes were pretreated with l-theanine for 72 h, and then treated with excess dopamine for further 24 h. The cell viability of dopamine neurons and levels of glutathione were evaluated. Excess dopamine-induced neurotoxicity was significantly attenuated by 72 h preincubation with l-theanine in neuron-astrocyte co-cultures but not in neuron-rich cultures. Exposure to l-theanine increased the levels of glutathione in both astrocytes and glial conditioned medium. The glial conditioned medium from l-theanine-pretreated striatal astrocytes attenuated dopamine-induced neurotoxicity and quinoprotein formation in mesencephalic neurons. In addition, replacement of l-glutamate with l-theanine in an in vitro cell-free glutathione-synthesis system produced glutathione-like thiol compounds. Furthermore, l-theanine administration (4 mg/kg, p.o.) for 14 days significantly increased glutathione levels in the striatum of mice. The results suggest that l-theanine provides neuroprotection against oxidative stress-induced neuronal damage by humoral molecules released from astrocytes, probably including glutathione.
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Affiliation(s)
- Mika Takeshima
- Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Ikuko Miyazaki
- Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Shinki Murakami
- Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; SAIDO Co., Fukuoka 810-0021, Japan
| | - Taizo Kita
- Laboratory of Pharmacology, Kyushu Nutrition Welfare University School of Health Science, Fukuoka 803-8511, Japan
| | - Masato Asanuma
- Department of Brain Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan; Department of Medical Neurobiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
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Unno K. Prevention of brain aging by green tea components: Role of catechins and theanine. ACTA ACUST UNITED AC 2016. [DOI: 10.7600/jpfsm.5.117] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Keiko Unno
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka
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Possible activation by the green tea amino acid theanine of mammalian target of rapamycin signaling in undifferentiated neural progenitor cells in vitro. Biochem Biophys Rep 2015; 5:89-95. [PMID: 28955810 PMCID: PMC5600317 DOI: 10.1016/j.bbrep.2015.09.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 09/28/2015] [Accepted: 09/28/2015] [Indexed: 11/23/2022] Open
Abstract
We have shown marked promotion of both proliferation and neuronal differentiation in pluripotent P19 cells exposed to the green tea amino acid theanine, which is a good substrate for SLC38A1 responsible for glutamine transport. In this study, we evaluated the activity of the mammalian target of rapamycin (mTOR) kinase pathway, which participates in protein translation, cell growth and autophagy in a manner relevant to intracellular glutamine levels, in murine neural progenitor cells exposed to theanine. Exposure to theanine promoted the phosphorylation of mTOR and downstream proteins in neurospheres from embryonic mouse neocortex. Although stable overexpression of SLC38A1 similarly facilitated phosphorylation of mTOR-relevant proteins in undifferentiated P19 cells, theanine failed to additionally accelerate the increased phosphorylation in these stable transfectants. Theanine accelerated the formation of neurospheres from murine embryonic neocortex and adult hippocampus, along with facilitation of both 5-bromo-2’-deoxyuridine incorporation and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide reduction in embryonic neurospheres. In embryonic neurospheres previously exposed to theanine, a significant increase was seen in the number of cells immunoreactive for a neuronal marker protein after spontaneous differentiation. These results suggest that theanine activates the mTOR signaling pathway for proliferation together with accelerated neurogenesis in murine undifferentiated neural progenitor cells. Theanine promotes mTOR phosphorylation in neural progenitors. Theanine promotes the formation of embryonic and adult neurospheres. SLC38A1 overexpression promotes mTOR phosphorylation in pluripotent P19 cells. Theanine fails to further promote mTOR phosphorylation in SLC38A1 transfectants. Theanine promotes subsequent neuronal differentiation in embryonic progenitors.
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Abstract
OBJECTIVES Glutamatergic dysfunction in the brain has been implicated in the pathophysiology of schizophrenia. Previous studies suggested that L-theanine affects the glutamatergic neurotransmission and ameliorates symptoms in patients with schizophrenia. The aims of the present study were twofold: to examine the possible effects of L-theanine on symptoms in chronic schizophrenia patients and to evaluate the changes in chemical mediators, including glutamate + glutamine (Glx), in the brain by using 1H magnetic resonance spectroscopy (MRS). METHOD The subjects were 17 patients with schizophrenia and 22 age- and sex-matched healthy subjects. L-theanine (250 mg/day) was added to the patients' ongoing antipsychotic treatment for 8 weeks. The outcome measures were the Positive and Negative Syndrome Scale (PANSS), Pittsburgh Sleep Quality Index scores and MRS results. RESULTS There were significant improvements in the PANSS positive scale and sleep quality after the L-theanine treatment. As for MRS, we found no significant differences in Glx levels before and after the 8 week L-theanine treatment. However, significant correlations were observed between baseline density of Glx and change in Glx density by l-theanine. CONCLUSIONS Our results suggest that L-theanine is effective in ameliorating positive symptoms and sleep quality in schizophrenia. The MRS findings suggest that L-theanine stabilises the glutamatergic concentration in the brain, which is a possible mechanism underlying the therapeutic effect.
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Upregulation of Slc38a1 Gene Along with Promotion of Neurosphere Growth and Subsequent Neuronal Specification in Undifferentiated Neural Progenitor Cells Exposed to Theanine. Neurochem Res 2015; 41:5-15. [PMID: 25957749 DOI: 10.1007/s11064-015-1591-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/23/2015] [Accepted: 04/27/2015] [Indexed: 02/04/2023]
Abstract
We have shown marked promotion of both cluster growth and neuronal specification in pluripotent P19 cells with overexpression of solute carrier 38a1 (Slc38a1), which is responsible for membrane transport of glutamine. In this study, we evaluated pharmacological profiles of the green tea amino acid ingredient theanine, which is a good substrate for glutamine transporters, on proliferation and neuronal specification in neural progenitor cells from embryonic rat neocortex. Sustained exposure to theanine, but not glutamine, accelerated the growth of neurospheres composed of proliferating cells and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) reducing activity at concentrations of 1-100 μM in undifferentiated progenitor cells. Such prior exposure to theanine promoted spontaneous and induced commitment to a neuronal lineage with concomitant deteriorated astroglial specification. Selective upregulation was seen in the expression of Slc38a1 in progenitor cells cultured with theanine. Similarly significant increases in cluster growth and MTT reducing activity were found in P19 cells cultured with theanine for 4 days. Luciferase activity was doubled in a manner sensitive to the deletion of promoter regions in P19 cells with a luciferase reporter plasmid of the Slc38a1 promoter after sustained exposure to theanine for 4 days. Overexpression of X-box binding protein-1 led to a marked increase in luciferase activity in P19 cells transfected with the Slc38a1 reporter plasmid. These results suggest that theanine accelerates cellular proliferation and subsequent neuronal specification through a mechanism relevant to upregulation of Slc38a1 gene in undifferentiated neural progenitor cells.
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Daily oral intake of theanine prevents the decline of 5-bromo-2′-deoxyuridine incorporation in hippocampal dentate gyrus with concomitant alleviation of behavioral abnormalities in adult mice with severe traumatic stress. J Pharmacol Sci 2015; 127:292-7. [DOI: 10.1016/j.jphs.2014.12.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 12/25/2014] [Accepted: 12/28/2014] [Indexed: 01/10/2023] Open
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The Involvement of L-Type Amino Acid Transporters in Theanine Transport. Biosci Biotechnol Biochem 2014; 76:2230-5. [DOI: 10.1271/bbb.120519] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Einöther SJ, Martens VE. Acute effects of tea consumption on attention and mood. Am J Clin Nutr 2013; 98:1700S-1708S. [PMID: 24172303 DOI: 10.3945/ajcn.113.058248] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Tea has historically been associated with mood and performance benefits, such as relaxation and concentration. This review summarizes the research on the acute effects of tea, and its ingredients theanine and caffeine, on attention and mood. Consistent with abundant research on the benefits of caffeine, the performance benefits of tea were identified in a number of studies, with particularly consistent evidence for improved attention. Tea consumption also consistently improved self-reported alertness and arousal, whereas effects on pleasure or relaxation were less consistent. In addition to the research on caffeine in real-life performance, 2 recent studies have provided a broader perspective on tea's effects on psychological function in that they showed beneficial effects in related areas such as work performance and creativity. These studies showed the validity of laboratory findings by supporting the idea that tea consumption has acute benefits on both mood and performance in real-life situations.
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Lardner AL. Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders. Nutr Neurosci 2013; 17:145-55. [PMID: 23883567 DOI: 10.1179/1476830513y.0000000079] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Theanine (n-ethylglutamic acid), a non-proteinaceous amino acid component of green and black teas, has received growing attention in recent years due to its reported effects on the central nervous system. It readily crosses the blood-brain barrier where it exerts a variety of neurophysiological and pharmacological effects. Its most well-documented effect has been its apparent anxiolytic and calming effect due to its up-regulation of inhibitory neurotransmitters and possible modulation of serotonin and dopamine in selected areas. It has also recently been shown to increase levels of brain-derived neurotrophic factor. An increasing number of studies demonstrate a neuroprotective effects following cerebral infarct and injury, although the exact molecular mechanisms remain to be fully elucidated. Theanine also elicits improvements in cognitive function including learning and memory, in human and animal studies, possibly via a decrease in NMDA-dependent CA1 long-term potentiation (LTP) and increase in NMDA-independent CA1-LTP. Furthermore, theanine administration elicits selective changes in alpha brain wave activity with concomitant increases in selective attention during the execution of mental tasks. Emerging studies also demonstrate a promising role for theanine in augmentation therapy for schizophrenia, while animal models of depression report positive improvements following theanine administration. A handful of studies are beginning to examine a putative role in attention deficit hyperactivity disorder, and theoretical extrapolations to a therapeutic role for theanine in other psychiatric disorders such as anxiety disorders, panic disorder, obsessive compulsive disorder (OCD), and bipolar disorder are discussed.
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Feng L, Yan Z, Sun B, Cai C, Jiang H, Kua EH, Ng TP, Qiu C. Tea consumption and depressive symptoms in older people in rural China. J Am Geriatr Soc 2013; 61:1943-7. [PMID: 24117348 DOI: 10.1111/jgs.12496] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVES To examine the association between tea consumption and depressive symptoms in Chinese older people and to explore the mediating role of cerebrovascular disease in the association. DESIGN Population-based cross-sectional study. SETTING A rural community near Qufu in Shandong, China. PARTICIPANTS Community-dwelling individuals aged 60 and older (mean 68.6; 59.3% female) from the Confucius Hometown Aging Project (N = 1,368). MEASUREMENTS Data were collected through interviews, clinical examinations, and psychological testing, following a standard procedure. Presence of high depressive symptoms was defined as a score of 5 or greater on the 15-item Geriatric Depression Scale. RESULTS Of the 1,368 participants, 165 (12.1%) were weekly and 489 (35.7%) were daily tea consumers. Compared with no or irregular tea consumption, controlling for age, sex, education, leisure activities, number of comorbidities, and Mini-Mental State Examination score, the odds ratios of having high depressive symptoms were 0.86 (95% confidence interval (CI) = 0.56-1.32) for weekly and 0.59 (95% CI = 0.43-0.81) for daily tea consumption (P for linear trend = .001); the linear trend of the association remained statistically significant when further controlling for history of stroke, transient ischemic attacks, and presence of carotid plaques. CONCLUSIONS Daily tea consumption is associated with a lower likelihood of depressive symptoms in Chinese older people living in a rural community. The association appears to be independent of cerebrovascular disease and atherosclerosis.
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Affiliation(s)
- Lei Feng
- Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore City, Singapore; Department of Psychological Medicine, National University Health System, Singapore
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