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Karunaratne UW, Dassanayake TL. Effect of L-theanine on selective attention in a traffic-related reaction task in sleep-deprived young adults: a double-blind placebo-controlled, crossover study. Nutr Neurosci 2024:1-10. [PMID: 39052627 DOI: 10.1080/1028415x.2024.2383080] [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: 07/27/2024]
Abstract
BACKGROUND L-theanine is a non-protein-forming amino acid found in tea. Limited evidence suggests that it improves selective attention. Sleep deprivation impairs attention and psychomotor reactions, affecting automobile driving. We aimed to determine whether L-theanine improves neurobehavioral measures of visual attention in acutely sleep-deprived healthy adults in a traffic-scene-based attention task. METHODS In a double-blind, placebo-controlled, counterbalanced, two-way crossover study, we compared the effects of a 200-mg dose of L-theanine with a placebo (150 ml of distilled water) on a computerised, traffic-scene-based visual recognition reaction task in 24 healthy volunteers (age 20-25 years; 13 males) sleep-deprived overnight. The participants made speeded button-presses to imminent accident scenes (i.e. hits), while ignoring safe scenes. They were tested pre-dose and 45 min post-dose, each treatment administered one week apart. RESULTS Hit rates were more than 90% in all sessions, and were similar in two treatments, pre- vs post-dose. L-theanine significantly reduced false alarms (i.e. responses to safe scenes) (p = 0.014) and increased A' (i.e. target-distractor discriminability) (p = 0.009), whereas placebo did not (p > 0.05). L-theanine reduced hit reaction time by 38.65 ms (p = 0.007), and placebo by 19.08 ms (p = 0.016), however reaction time changes from baseline were not significantly different between treatments (p > 0.05). CONCLUSIONS L-theanine in high doses appears to improve selective visual attention by concurrently improving information processing speed and target-distractor discriminability in acutely sleep-deprived individuals. This is consistent with previous functional neuroimaging findings, where L-theanine suppressed distractor-processing and default-mode-network activity in visual selective attention tasks.
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Affiliation(s)
- Umangi W Karunaratne
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
| | - Tharaka L Dassanayake
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
- School of Psychological Sciences, The University of Newcastle, Callaghan, Australia
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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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Yamaura S, Sadamori K, Konishi R, Majima T, Mukai A, Uno K, Kinjo T, Komori K, Kuramoto N, Kawada K. Pharmacokinetics of L-theanine and the effect on amino acid composition in mice administered with L-theanine. Amino Acids 2024; 56:29. [PMID: 38583116 PMCID: PMC10999383 DOI: 10.1007/s00726-024-03389-3] [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: 09/01/2023] [Accepted: 03/12/2024] [Indexed: 04/08/2024]
Abstract
L-theanine, an amino acid component of the tea leaves of Camellia sinensis, is sold in Japan as a supplement for good sleep. Although several studies in humans and mice have reported the effects of L-theanine on brain function, only a few reports have comprehensively clarified the disposition of theanine administered to mice and its effects on concentrations of other blood amino acids. In this study, we aimed to determine the changes in the blood levels of L-theanine administered to mice and amino acid composition of the serum. L-theanine were administered to four-week-old Std-ddY male mice orally or via tail vein injection. L-theanine and other amino acids in serum prepared from blood collected at different time points post-dose were labeled with phenylisothiocyanate and quantified. The serum concentration of orally administered L-theanine peaked 15 min after administration. The area under the curve for tail vein injection revealed the bioavailability of L- theanine to be approximately 70%. L-theanine administration did not affect any amino acid levels in the serum, but a significant increase in the peak area overlapping the Glycine (Gly) peak was observed 30 min after administration. L-theanine administered to mice was rapidly absorbed and eliminated, suggesting that taking L-theanine as a supplement is safe without affecting its own levels or serum levels of other amino acids. However, considering that Gly, similar to L-theanine, is used as a dietary supplement for its anxiolytic effects and to improve sleep, determining the effects of L-theanine administration on Gly is important and needs further research.
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Affiliation(s)
- Shinnosuke Yamaura
- Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Koki Sadamori
- Department of Bioactive Molecules, Pharmacology, Gifu Pharmaceutical University, Gifu, Japan
| | - Reiko Konishi
- Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Takashi Majima
- Department of Nursing, Faculty of Allied Health Sciences, Yamato University, Suita, Osaka, Japan
| | - Akira Mukai
- Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Kyosuke Uno
- Laboratory of Molecular Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Toshihiko Kinjo
- Laboratory of Molecular Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Koji Komori
- Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan.
| | - Nobuyuki Kuramoto
- Laboratory of Molecular Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Kou Kawada
- Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
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McAllister MJ, Martaindale MH, Dillard CC, McCullough R. Impact of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality based active shooter training drill. Stress 2024; 27:2375588. [PMID: 38975711 DOI: 10.1080/10253890.2024.2375588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 06/25/2024] [Indexed: 07/09/2024] Open
Abstract
Ingestion of L-theanine and L-tyrosine has been shown to reduce salivary stress biomarkers and improve aspects of cognitive performance in response to stress. However, there have been no studies to concurrently examine the impact of both L-theanine and L-tyrosine ingestion during a mental stress challenge (MSC) involving a brief cognitive challenge and a virtual reality based active shooter training drill. Thus, the purpose of this study was to determine the impact of ingestion of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality active shooter drill and cognitive challenge. The cognitive challenge involved a Stroop challenge and mental arithmetic. Eighty subjects (age = 21 ± 2.6 yrs; male = 46; female = 34) were randomly assigned L-tyrosine (n = 28; 2000 mg), L-theanine (n = 25; 200 mg), or placebo (n = 27) prior to MSC exposure. Saliva samples, state-anxiety inventory (SAI) scales, and heart rate (HR) were collected before and after exposure to the MSC. Saliva was analyzed for stress markers α-amylase (sAA) and secretory immunoglobulin A (SIgA). The MSC resulted in significant increases in sAA, SIgA, HR, and SAI. Ingestion of L-theanine and L-tyrosine did not impact markers of stress. However, the L-tyrosine treatment demonstrated significantly lower missed responses compared to the placebo treatment group during the Stroop challenge. These data demonstrate that ingestion of L-theanine or L-tyrosine does not impact markers of stress in response to a MSC but may impact cognitive performance. This study was pre-registered as a clinical trial ("Impact of supplements on stress markers": NCT05592561).
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Affiliation(s)
- Matthew J McAllister
- Metabolic & Applied Physiology Laboratory, Department of Health & Human Performance, Texas State University, San Marcos, TX, USA
| | | | - Courtney C Dillard
- Metabolic & Applied Physiology Laboratory, Department of Health & Human Performance, Texas State University, San Marcos, TX, USA
| | - Rory McCullough
- Metabolic & Applied Physiology Laboratory, Department of Health & Human Performance, Texas State University, San Marcos, TX, USA
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Luo Q, Luo L, Zhao J, Wang Y, Luo H. Biological Potential and Mechanisms of Tea's Bioactive Compounds in Tea: An Updated Review. J Adv Res 2023:S2090-1232(23)00378-8. [PMID: 38056775 DOI: 10.1016/j.jare.2023.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/28/2023] [Accepted: 12/02/2023] [Indexed: 12/08/2023] Open
Abstract
BACKGROUND Tea (Camellia sinensis) has a rich history and is widely consumed across many countries, and is categorized into green tea, white tea, oolong tea, yellow tea, black tea, and dark tea based on the level of fermentation. Based on a review of previous literature, the commonly recognized bioactive substances in tea include tea polyphenols, amino acids, polysaccharides, alkaloids, terpenoids, macro minerals, trace elements, and vitamins, which have been known to have various potential health benefits, such as anticancer, antioxidant, anti-inflammatory, anti-diabetes, and anti-obesity properties, cardiovascular protection, immune regulation, and control of the intestinal microbiota. Most studies have only pointed out the characteristics of tea's bioactivities, so a comprehensive summary of the pharmacological characteristics and mechanisms of tea's bioactivities and their use risks are vital. AIM of Review The aim of this paper is to summarize the bioactive substances of tea and their pharmacological characteristics and mechanisms, providing a scientific basis for the application of bioactive substances in tea and outlining future research directions for the study of bioactive substances in tea. Key Scientific Concepts of Review This review summarizes the main biologically active substances, pharmacological effects, and mechanisms and discusses the potential risks. It may help researchers to grasp more comprehensive progress in the study of tea bioactive substances to further promote the application of tea as a natural bioactive substance in the medical field.
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Affiliation(s)
- Qiaoxian Luo
- Macau Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, 999078, P. R. China; These authors contributed equally to this work
| | - Longbiao Luo
- Macau Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, 999078, P. R. China; These authors contributed equally to this work
| | - Jinmin Zhao
- College of Pharmacy, Guangxi Medical University, Nanning, 530021, P. R. China
| | - Yitao Wang
- Macau Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, 999078, P. R. China.
| | - Hua Luo
- Macau Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, 999078, P. R. China; College of Pharmacy, Guangxi Medical University, Nanning, 530021, P. R. China.
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6
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Yilmaz U, Buzdagli Y, Polat ML, Bakir Y, Ozhanci B, Alkazan S, Ucar H. Effect of single or combined caffeine and L-Theanine supplementation on shooting and cognitive performance in elite curling athletes: a double-blind, placebo-controlled study. J Int Soc Sports Nutr 2023; 20:2267536. [PMID: 37815006 PMCID: PMC10566444 DOI: 10.1080/15502783.2023.2267536] [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: 08/06/2023] [Accepted: 10/03/2023] [Indexed: 10/11/2023] Open
Abstract
PURPOSE Previous studies have investigated the effect of single or combined caffeine (CAF) and L-theanine (THE) intake on attention performance. However, its effect on shooting performance and cognitive performance in a sport is unknown. The aim of this study was to investigate the hypothesis "Does single or combined CAF and THE supplementation have an effect on shooting and cognitive performance in elite curling athletes?." It is predicted that over the next decade, studies based on nutritional ergogenic supplements in the developing sport of curling will continue to increase, leading to a significant increase in studies examining the effects of CAF and THE supplementation, alone or in combination, on throwing and cognitive performance in elite curling athletes. METHODS In this double-blind, randomized controlled crossover study, twenty-two elite national curling athletes (age 20.20 ± 1.61 and sports age 6.20 ± 0.51 years, height 174.10 ± 7.21 cm, BMI 21.80 ± 3.47 kg/m2) were randomly assigned to CAF (6 mg/kg single dose CAF), THE (6 mg/kg single dose THE), CAF*THE (6 mg/kg CAF and 6 mg/kg THE combined) and PLA (400 mg maltodextrin) groups at each of four sessions. 60 minutes after taking the supplement, the athletes were first given the Stroop test and then asked to shoot. RESULTS Our main findings have shown that the performance of athletes in guard (F=3.452, P < .001, ηp2 = .842), draw (F=1.647, P < .001, ηp2 = .485), and take-out (F=3.121, P < .001, ηp2 = .743) shot styles significantly improved when comparing the combined intake of CAF and THE to the PLA. Regarding cognitive performance evaluation through the Stroop test, during the NR task (F=4.743, P = .001, ηp2 = .653), the combined intake of CAF and THE significantly improved reaction times compared to the intake of single CAF, THE, or PLA. The best reaction times during the CR and ICR (respectively; F=2.742, P = .004, ηp2 = .328; F = 1.632, P < .001, ηp2 = .625) tasks were achieved with the combined CAF and THE intake, showing a significant improvement compared to PLA. During the NER (F=2.961, P < .001, ηp2 = .741), task, the combined intake of CAF and THE significantly improved error rates compared to the intake of CAF, THE, or PLA single. The best accuracy rates during the CER and ICER (respectively; F=4.127, P < .001, ηp2 = .396; F=3.899, P < .001, ηp2 = .710) tasks were achieved with the combined CAF and THE intake, leading to a significant reduction in error rates compared to PLA. Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE. CONCLUSIONS Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE. The combined use of these supplements has been found to be more effective on shooting and cognitive performance than their single use.
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Affiliation(s)
- Umut Yilmaz
- Hakkâri University, Department of Physical Education and Sports, Faculty of Education, Hakkâri, Turkey
| | - Yusuf Buzdagli
- Erzurum Technical University, Department of Coaching Education, Faculty of Sport Sciences, Erzurum, Turkey
| | | | - Yusuf Bakir
- Erzurum Technical University, Institute of Health Sciences, Erzurum, Turkey
| | - Burak Ozhanci
- Erzurum Technical University, Institute of Health Sciences, Erzurum, Turkey
| | - Sena Alkazan
- Erzurum Technical University, Institute of Health Sciences, Erzurum, Turkey
| | - Halil Ucar
- Atatürk University, Institute of Winter Sports and Sport Sciences, Erzurum, Turkey
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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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Matcha Tea Powder's Antidepressant-like Effect through the Activation of the Dopaminergic System in Mice Is Dependent on Social Isolation Stress. Nutrients 2023; 15:nu15030581. [PMID: 36771286 PMCID: PMC9921318 DOI: 10.3390/nu15030581] [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: 12/09/2022] [Revised: 01/02/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023] Open
Abstract
Matcha tea powder is believed to have various physiological benefits; however, its detailed mechanism of action has been poorly understood. Here, we investigated whether the mental state of mice, due to social isolation stress, affects the antidepressant-like effect of Matcha tea powder by using the tail suspension test. Oral administration of Matcha tea powder reduced the duration of immobility in the stress-susceptible C57BL/6J strain, but not in BALB/c strain. In C57BL/6J mice, SCH23390, a dopamine D1 receptor blocker, prevented Matcha tea powder from exerting its antidepressant-like effect. Matcha tea powder also increased the number of c-Fos-positive cells in the prefrontal cortex (PFC) region and the nucleus accumbens (NAc) region in C57BL/6J mice, but not in BALB/c mice. In contrast, Matcha tea powder did not change the number of c-Fos-positive cells in the ventral tegmental area (VTA) region. Notably, C57BL/6J mice with a shorter immobility time had a higher number of c-Fos-positive cells in the PFC, NAc, and VTA regions. However, no such correlation was observed in the stress-tolerant BALB/c mice. These results suggest that Matcha tea powder exerts an antidepressant-like effect through the activation of the dopaminergic system including the PFC-NAc-VTA circuit and that mental states are important factors affecting the physiological benefits of Matcha tea powder.
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Unno K, Nakamura Y. Green Tea Suppresses Brain Aging. Molecules 2021; 26:molecules26164897. [PMID: 34443485 PMCID: PMC8401650 DOI: 10.3390/molecules26164897] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/06/2021] [Accepted: 08/10/2021] [Indexed: 12/20/2022] Open
Abstract
Epidemiological studies have demonstrated that the intake of green tea is effective in reducing the risk of dementia. The most important component of green tea is epigallocatechin gallate (EGCG). Both EGCG and epigallocatechin (EGC) have been suggested to cross the blood–brain barrier to reach the brain parenchyma, but EGCG has been found to be more effective than EGC in promoting neuronal differentiation. It has also been suggested that the products of EGCG decomposition by the intestinal microbiota promote the differentiation of nerve cells and that both EGCG and its degradation products act on nerve cells with a time lag. On the other hand, the free amino acids theanine and arginine contained in green tea have stress-reducing effects. While long-term stress accelerates the aging of the brain, theanine and arginine suppress the aging of the brain due to their anti-stress effect. Since this effect is counteracted by EGCG and caffeine, the ratios between these green tea components are important for the anti-stress action. In this review, we describe how green tea suppresses brain aging, through the activation of nerve cells by both EGCG and its degradation products, and the reductions in stress achieved by theanine and arginine.
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Evans M, Sulley AM, Crowley DC, Langston J, Guthrie N. Pain Bloc-R Alleviates Unresolved, Non-Pathological Aches and Discomfort in Healthy Adults—A Randomized, Double-Blind, Placebo-Controlled, Crossover Study. Nutrients 2020; 12:nu12061831. [PMID: 32575480 PMCID: PMC7353407 DOI: 10.3390/nu12061831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 11/25/2022] Open
Abstract
The lack of effective treatment for chronic discomfort without negative side effects highlights the need for alternative treatments. Pain Bloc-R is a natural health product composed of vitamins B6, B12, D, white willow bark extract, Angelica root extract, acetyl L-carnitine HCl, caffeine, L-theanine, Benfotiamine, and L-tetrahydropalmatine. The objective of this study was to compare the effects of Pain Bloc-R, acetaminophen, and placebo on unresolved aches and discomfort as assessed by the brief pain inventory (BPI) and modified Cornell musculoskeletal discomfort questionnaires. This randomized, double-blind, placebo-controlled, crossover study consisted of three 7-day periods with Pain Bloc-R, acetaminophen, or placebo, each separated by a 7-day washout. Twenty-seven healthy adults (ages 22–63 years) were randomized to receive the three interventions in different sequences. The BPI “pain at its worst” scores were significantly lower when participants took Pain Bloc-R than when they took acetaminophen (21.8% vs. 9.8% decrease, p = 0.026) after seven days of supplementation. Pain Bloc-R achieved a significant improvement in the “pain at its least” score, significantly decreased the interference of discomfort in walking, and significantly decreased musculoskeletal discomfort total scores (34%, p = 0.040) after seven days. In a post hoc subgroup analysis based on age and gender, male participants ≤45 years taking Pain Bloc-R reported significant reductions in pain severity and pain interference vs. acetaminophen. Pain Bloc-R performed as well as acetaminophen in managing unresolved non-pathological pain in otherwise healthy individuals.
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Affiliation(s)
- Malkanthi Evans
- KGK Science Inc., London, ON N6A 5R8, Canada; (A.M.S.); (D.C.C.); (N.G.)
- Correspondence:
| | - Abdul M. Sulley
- KGK Science Inc., London, ON N6A 5R8, Canada; (A.M.S.); (D.C.C.); (N.G.)
| | - David C. Crowley
- KGK Science Inc., London, ON N6A 5R8, Canada; (A.M.S.); (D.C.C.); (N.G.)
| | | | - Najla Guthrie
- KGK Science Inc., London, ON N6A 5R8, Canada; (A.M.S.); (D.C.C.); (N.G.)
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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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Hidese S, Ogawa S, Ota M, Ishida I, Yasukawa Z, Ozeki M, Kunugi H. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients 2019; 11:nu11102362. [PMID: 31623400 PMCID: PMC6836118 DOI: 10.3390/nu11102362] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/26/2019] [Accepted: 09/29/2019] [Indexed: 01/10/2023] Open
Abstract
This randomized, placebo-controlled, crossover, and double-blind trial aimed to examine the possible effects of four weeks L-theanine administration on stress-related symptoms and cognitive functions in healthy adults. Participants were 30 individuals (nine men and 21 women; age: 48.3 ± 11.9 years) who had no major psychiatric illness. L-theanine (200 mg/day) or placebo tablets were randomly and blindly assigned for four-week administration. For stress-related symptoms, Self-rating Depression Scale, State-Trait Anxiety Inventory-trait, and Pittsburgh Sleep Quality Index (PSQI) scores decreased after L-theanine administration (p = 0.019, 0.006, and 0.013, respectively). The PSQI subscale scores for sleep latency, sleep disturbance, and use of sleep medication reduced after L-theanine administration, compared to the placebo administration (all p < 0.05). For cognitive functions, verbal fluency and executive function scores improved after L-theanine administration (p = 0.001 and 0.031, respectively). Stratified analyses revealed that scores for verbal fluency (p = 0.002), especially letter fluency (p = 0.002), increased after L-theanine administration, compared to the placebo administration, in individuals who were sub-grouped into the lower half by the median split based on the mean pretreatment scores. Our findings suggest that L-theanine has the potential to promote mental health in the general population with stress-related ailments and cognitive impairments.
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Affiliation(s)
- Shinsuke Hidese
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
| | - Shintaro Ogawa
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
| | - Miho Ota
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
| | - Ikki Ishida
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
| | - Zenta Yasukawa
- Department of Research and Development, Nutrition Division, Taiyo Kagaku Co. Ltd, 1-3, Takara-machi, Yokkaichi, Mie 510-0844, Japan.
| | - Makoto Ozeki
- Department of Research and Development, Nutrition Division, Taiyo Kagaku Co. Ltd, 1-3, Takara-machi, Yokkaichi, Mie 510-0844, Japan.
| | - Hiroshi Kunugi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan.
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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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15
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Pyke RE. Sexual Performance Anxiety. Sex Med Rev 2019; 8:183-190. [PMID: 31447414 DOI: 10.1016/j.sxmr.2019.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Sexual performance anxiety (SPA) is one of the most prevalent sexual complaints; yet, no diagnosis is recognized for either gender. Thus, research into treatment has been minimal. AIM Review the prevalence of SPA and its relation to sexual dysfunctions and anxiety disorders. Compare SPA to (non-sexual) performance anxiety and social anxiety (PA/SA). Apply pharmacologic principles to the known properties of drugs and phytotherapies to hypothesize treatments for SPA. METHODS Review SPA and PA/SA through PubMed searches for relevant literature from 2000 to 2018. MAIN OUTCOME MEASURE Prevalence was estimated using population-representative surveys. For treatment results, controlled clinical trial results were prioritized over open-label trial results. RESULTS SPA affects 9-25% of men and contributes to premature ejaculation and psychogenic erectile dysfunction (ED). SPA affects 6-16% of women and severely inhibits sexual desire. Cognitive behavior therapy and mindfulness meditation training have been proven effective for PA/SA and are recommended for SPA, but controlled studies are lacking. Phosphodiesterase type 5 inhibitors are effective for psychogenic ED and premature ejaculation, both of which include SPA as a major element. Drugs proven for PA/SA have adverse sexual and sedative effects, but serotonergic anxiolytics with prosexual effects (buspirone ± testosterone, trazodone ± bupropion) may have potential, and sage, passionflower, l-theanine, and bitter orange are anxiolytic. Nitric oxide boosters (l-citrulline, l-arginine, Panax ginseng) have the potential for increasing genital tumescence and lubrication, and plant-based alpha-adrenergic antagonists may aid sexual arousal (yohimbine/yohimbe, Citrus aurantium/p-synephrine). CONCLUSION SPA causes or maintains most common sexual dysfunction. No treatments are well proven, although cognitive behavior therapy, mindfulness meditation training, and serotonergic anxiolytics (buspirone, trazodone, gepirone) have potential, and phosphodiesterase type 5 inhibitors are effective for psychogenic ED and premature ejaculation. Several phytotherapies also appear to have potential. Pyke RE. Sexual Performance Anxiety. J Sex Med 2020;8:183-190.
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16
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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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17
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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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18
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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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19
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Williams J, Sergi D, McKune AJ, Georgousopoulou EN, Mellor DD, Naumovski N. The beneficial health effects of green tea amino acid l
-theanine in animal models: Promises and prospects for human trials. Phytother Res 2019; 33:571-583. [DOI: 10.1002/ptr.6277] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 11/29/2018] [Accepted: 12/10/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Jackson Williams
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
| | - Domenico Sergi
- Commonwealth Scientific and Industrial Research Organisation (CSIRO)-Health and Biosecurity; Adelaide SA Australia
| | - Andrew J. McKune
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
- University of Canberra Research Institute for Sport and Exercise (UCRISE); Bruce ACT Australia
- Discipline of Biokinetics, Exercise and Leisure Sciences, School of Health Sciences; University of KwaZulu-Natal; Durban South Africa
| | - Ekavi N. Georgousopoulou
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
- Department of Nutrition and Dietetics, School of Health Science and Education; Harokopio University; Athens Greece
| | - Duane D. Mellor
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
| | - Nenad Naumovski
- Faculty of Health; University of Canberra; Canberra ACT Australia
- Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, University of Canberra; Bruce ACT Australia
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20
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Zhu G, Yang S, Xie Z, Wan X. Synaptic modification by L-theanine, a natural constituent in green tea, rescues the impairment of hippocampal long-term potentiation and memory in AD mice. Neuropharmacology 2018; 138:331-340. [DOI: 10.1016/j.neuropharm.2018.06.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 06/21/2018] [Accepted: 06/22/2018] [Indexed: 02/08/2023]
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21
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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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22
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Blum K, Modestino EJ, Gondré-Lewis M, Downs BW, Baron D, Steinberg B, Siwicki D, Giordano J, McLaughlin T, Neary J, Hauser M, Fried L, Badgaiyan RD. "Dopamine homeostasis" requires balanced polypharmacy: Issue with destructive, powerful dopamine agents to combat America's drug epidemic. ACTA ACUST UNITED AC 2017; 3. [PMID: 30197787 PMCID: PMC6128292 DOI: 10.15761/jsin.1000183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The well-researched pro-dopamine regulator KB220 and variants result in increased functional connectivity in both animal and human brains, and prolonged neuroplasticity (brain cell repair) having been observed in rodents. Moreover, in addition to increased functional connectivity, recent studies show that KB220Z increases overall brain connectivity volume, enhances neuronal dopamine firing, and eliminates lucid dreams in humans over a prolonged period. An unprecedented number of clinical studies validating this patented nutrigenomic technology in re-balancing brain chemistry and optimizing dopamine sensitivity and function have been published. On another note, it is sad that unsuspecting consumers could be deceived and endangered by false promises of knock-off marketers with look- and- sound-alike products. Products containing ingredients having potential dangers (i.e., combinations of potent D2 agonists including L-Dopa and L-Theanine) threaten the credibility and reputation of validated, authentic, and ethical products. We encourage clinicians and neuroscientists to continue to embrace the concept of “dopamine homeostasis” and search for safe, effective, validated and authentic means to achieve a lifetime of recovery, instead of reverting to anti-dopaminergic agents doomed to fail in the war against the devastating drug epidemic, or promoting powerful D2 agonists that compromise needed balance.
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Affiliation(s)
- Kenneth Blum
- Department of Psychiatry, University of Florida & McKnight Brain Institute, College of Florida, Gainesville, FL, USA.,Department of Psychiatry, Human Integrated Services Unit University of Vermont Center for Clinical & Translational Science, College of Medicine, Burlington, VT, USA.,Dominion Diagnostics, LLC, North Kingstown, RI, USA.,Department of Psychiatry, Wright State University, Boonshoft School of Medicine, Dayton, OH USA.,Division of Genetic Testing, Geneus Health LLC, San Antonio, Texas, USA.,Center for Genomics and Applied Gene Technology, Institute of Integrative Omics and Applied Biotechnology (IIOAB), Nonakuri, Purba Medinipur, West Bengal, India.,Institute of Psychology, Eötvös Loránd University Budapest, Hungary.,Department of Psychiatry, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA.,Division of Addiction Research & Therapy, The Shores Treatment & Recovery Center, Port St Lucie, Fl, USA.,Victory Nutition International, Inc., Lederach, PA, USA.,John Giordano's Life Enhancement Aftercare Recovery Center, Ft. Lauderdale, FL, USA
| | | | - Marjorie Gondré-Lewis
- Departments of Anatomy and Psychiatry and Behavioral Sciences, Howard University, Washington, DC, USA
| | | | - David Baron
- Department of Psychiatry, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA
| | | | - David Siwicki
- Division of Genetic Testing, Geneus Health LLC, San Antonio, Texas, USA
| | - John Giordano
- John Giordano's Life Enhancement Aftercare Recovery Center, Ft. Lauderdale, FL, USA
| | | | - Jennifer Neary
- Division of Genetic Testing, Geneus Health LLC, San Antonio, Texas, USA
| | - Mary Hauser
- Dominion Diagnostics, LLC, North Kingstown, RI, USA
| | - Lyle Fried
- Division of Addiction Research & Therapy, The Shores Treatment & Recovery Center, Port St Lucie, Fl, USA
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Kahathuduwa CN, Dhanasekara CS, Chin SH, Davis T, Weerasinghe VS, Dassanayake TL, Binks M. l-Theanine and caffeine improve target-specific attention to visual stimuli by decreasing mind wandering: a human functional magnetic resonance imaging study. Nutr Res 2017; 49:67-78. [PMID: 29420994 DOI: 10.1016/j.nutres.2017.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 10/31/2017] [Accepted: 11/12/2017] [Indexed: 11/17/2022]
Abstract
Oral intake of l-theanine and caffeine supplements is known to be associated with faster stimulus discrimination, possibly via improving attention to stimuli. We hypothesized that l-theanine and caffeine may be bringing about this beneficial effect by increasing attention-related neural resource allocation to target stimuli and decreasing deviation of neural resources to distractors. We used functional magnetic resonance imaging (fMRI) to test this hypothesis. Solutions of 200mg of l-theanine, 160mg of caffeine, their combination, or the vehicle (distilled water; placebo) were administered in a randomized 4-way crossover design to 9 healthy adult men. Sixty minutes after administration, a 20-minute fMRI scan was performed while the subjects performed a visual color stimulus discrimination task. l-Theanine and l-theanine-caffeine combination resulted in faster responses to targets compared with placebo (∆=27.8milliseconds, P=.018 and ∆=26.7milliseconds, P=.037, respectively). l-Theanine was associated with decreased fMRI responses to distractor stimuli in brain regions that regulate visual attention, suggesting that l-theanine may be decreasing neural resource allocation to process distractors, thus allowing to attend to targets more efficiently. l-Theanine-caffeine combination was associated with decreased fMRI responses to target stimuli as compared with distractors in several brain regions that typically show increased activation during mind wandering. Factorial analysis suggested that l-theanine and caffeine seem to have a synergistic action in decreasing mind wandering. Therefore, our hypothesis is that l-theanine and caffeine may be decreasing deviation of attention to distractors (including mind wandering); thus, enhancing attention to target stimuli was confirmed.
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Affiliation(s)
- Chanaka N Kahathuduwa
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA; Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka; Department of Human Development and Family Studies, Texas Tech University, Lubbock, TX, USA
| | - Chathurika S Dhanasekara
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA
| | - Shao-Hua Chin
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA
| | - Tyler Davis
- Department of Human Development and Family Studies, Texas Tech University, Lubbock, TX, USA; Department of Psychological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Vajira S Weerasinghe
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka
| | - Tharaka L Dassanayake
- Department of Physiology, Faculty of Medicine, University of Peradeniya, Sri Lanka; School of Psychology, The University of Newcastle, New South Wales, Australia
| | - Martin Binks
- Behavioral Medicine and Translational Research Lab, Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, USA.
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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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25
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L-theanine prevent quinolinic acid induced motor deficit and striatal neurotoxicity: Reduction in oxido-nitrosative stress and restoration of striatal neurotransmitters level. Eur J Pharmacol 2017. [DOI: 10.1016/j.ejphar.2017.06.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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26
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Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatr 2017; 29:72-79. [PMID: 27396868 DOI: 10.1017/neu.2016.33] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE l-theanine, an amino acid uniquely contained in green tea (Camellia sinensis), has been suggested to have various psychotropic effects. This study aimed to examine whether l-theanine is effective for patients with major depressive disorder (MDD) in an open-label clinical trial. METHODS Subjects were 20 patients with MDD (four males; mean age: 41.0±14.1 years, 16 females; 42.9±12.0 years). l-theanine (250 mg/day) was added to the current medication of each participant for 8 weeks. Symptoms and cognitive functions were assessed at baseline, 4, and 8 weeks after l-theanine administration by the 21-item version of the Hamilton Depression Rating Scale (HAMD-21), State-Trait Anxiety Inventory (STAI), Pittsburgh Sleep Quality Index (PSQI), Stroop test, and Brief Assessment of Cognition in Schizophrenia (BACS). RESULTS HAMD-21 score was reduced after l-theanine administration (p=0.007). This reduction was observed in unremitted patients (HAMD-21>7; p=0.004) at baseline. Anxiety-trait scores decreased after l-theanine administration (p=0.012) in the STAI test. PSQI scores also decreased after l-theanine administration (p=0.030) in the unremitted patients at baseline. Regarding cognitive functions, response latency (p=0.001) and error rate (p=0.036) decreased in the Stroop test, and verbal memory (p=0.005) and executive function (p=0.016) were enhanced in the BACS test after l-theanine administration. CONCLUSION Our study suggests that chronic (8-week) l-theanine administration is safe and has multiple beneficial effects on depressive symptoms, anxiety, sleep disturbance and cognitive impairments in patients with MDD. However, since this is an open-label study, placebo-controlled studies are required to consolidate the effects.
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Yu XC, Wu BL, Gao JC, Yang W. Theanine enhanced both the toxicity of strychnine and anticonvulsion of pentobarbital sodium. Drug Chem Toxicol 2015; 39:217-23. [DOI: 10.3109/01480545.2015.1080264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Inoue K, Miyazaki Y, Unno K, Min JZ, Todoroki K, Toyo'oka T. Stable isotope dilution HILIC-MS/MS method for accurate quantification of glutamic acid, glutamine, pyroglutamic acid, GABA and theanine in mouse brain tissues. Biomed Chromatogr 2015; 30:55-61. [DOI: 10.1002/bmc.3502] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 04/16/2015] [Accepted: 04/28/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Koichi Inoue
- Laboratory of Clinical and Analytical Chemistry, College of Pharmaceutical Sciences; Ritsumeikan University; 1-1-1 Nojihigashi Kusatsu Shiga 525-8577 Japan
- Laboratory of Analytical and Bio-Analytical Chemistry, School of Pharmaceutical Sciences; University of Shizuoka; 52-1 Yada Suruga-ku Shizuoka 422-8526 Japan
| | - Yasuto Miyazaki
- Laboratory of Analytical and Bio-Analytical Chemistry, School of Pharmaceutical Sciences; University of Shizuoka; 52-1 Yada Suruga-ku Shizuoka 422-8526 Japan
| | - Keiko Unno
- Department of Neurophysiology, School of Pharmaceutical Sciences; University of Shizuoka; 52-1 Yada Shizuoka 422-8526 Japan
| | - Jun Zhe Min
- Laboratory of Analytical and Bio-Analytical Chemistry, School of Pharmaceutical Sciences; University of Shizuoka; 52-1 Yada Suruga-ku Shizuoka 422-8526 Japan
| | - Kenichiro Todoroki
- Laboratory of Analytical and Bio-Analytical Chemistry, School of Pharmaceutical Sciences; University of Shizuoka; 52-1 Yada Suruga-ku Shizuoka 422-8526 Japan
| | - Toshimasa Toyo'oka
- Laboratory of Analytical and Bio-Analytical Chemistry, School of Pharmaceutical Sciences; University of Shizuoka; 52-1 Yada Suruga-ku Shizuoka 422-8526 Japan
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The neuroprotective effect of L-Theanine and its inhibition on nicotine dependence. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s11434-014-0529-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Yoto A, Murao S, Nakamura Y, Yokogoshi H. Intake of green tea inhibited increase of salivary chromogranin A after mental task stress loads. J Physiol Anthropol 2014; 33:20. [PMID: 25034805 PMCID: PMC4118660 DOI: 10.1186/1880-6805-33-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 06/30/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Green tea has become renowned for its health benefits. In this study, we investigated the anti-stress effect of two kinds of green tea against a mental stress task load. METHODS Warm water, ordinary green tea (Sagara), and shaded white tea, which contains more amino acid components than Sagara, were used as test samples in a randomized cross-over design study. Eighteen students (nine male and nine female) participated in three experimental trials on different days at intervals of seven days. Saliva was collected before beverage intake and after performing the mental stress load tasks. Concentration of chromogranin A (CgA) in the saliva was used as an index of autonomic nervous system activity. RESULTS CgA level increased after the mental tasks, but intake of green tea inhibited this increase; the anti-stress effect was even greater after consumption of shaded white tea. Intake of shaded white tea also lowered Total Mood Disturbance (TMD) score on the Profile of Mood States (POMS); subjects in this condition tended to perform more calculations in the arithmetic task than those in the warm water treatment condition. CONCLUSIONS Salivary CgA concentration levels increased after mental stress load tasks, but ingestion of green tea inhibited this increase. This anti-stress effect was larger after the consumption of shaded white tea than after Sagara. Shaded white tea intake also lowered TMD score (POMS) and tended to improve performance on an arithmetic task compared to warm water, suggesting that shaded white tea might also improve mood during and after mental stress load.
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Affiliation(s)
- Ai Yoto
- School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan.
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Administration of Theanine, a Unique Amino Acid in Tea Leaves, Changed Feeding-Relating Components in Serum and Feeding Behavior in Rats. Biosci Biotechnol Biochem 2014; 72:1352-5. [DOI: 10.1271/bbb.70668] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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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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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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Li Y, Zou L, Song G, Li K, Ye B. Electrochemical behavior of sophoridine at a new amperometric sensor based on l-Theanine modified electrode and its sensitive determination. J Electroanal Chem (Lausanne) 2013. [DOI: 10.1016/j.jelechem.2013.09.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Yoto A, Motoki M, Murao S, Yokogoshi H. Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. J Physiol Anthropol 2012; 31:28. [PMID: 23107346 PMCID: PMC3518171 DOI: 10.1186/1880-6805-31-28] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 10/08/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND L-theanine, an amino acid contained in green tea leaves, is known to block the binding of L-glutamic acid to glutamate receptors in the brain, and has been considered to cause anti-stress effects by inhibiting cortical neuron excitation. Both L-theanine and caffeine, which green tea contains, have been highlighted for their beneficial effects on cognition and mood. METHODS In this study, we investigated the effects of orally administered L-theanine or caffeine on mental task performance and physiological activities under conditions of physical or psychological stress in humans. Fourteen participants each underwent three separate trials, in which they orally took either L-theanine + placebo, caffeine + placebo, or placebo only. RESULTS The results after the mental tasks showed that L-theanine significantly inhibited the blood-pressure increases in a high-response group, which consisted of participants whose blood pressure increased more than average by a performance of a mental task after placebo intake. Caffeine tended to have a similar but smaller inhibition of the blood-pressure increases caused by the mental tasks. The result of the Profile of Mood States after the mental tasks also showed that L-theanine reduced the Tension-Anxiety scores as compared with placebo intake. CONCLUSIONS The findings above denote that L-theanine not only reduces anxiety but also attenuates the blood-pressure increase in high-stress-response adults.
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Affiliation(s)
- Ai Yoto
- Laboratory of Nutritional Biochemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
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SUZUKI Y, MIYOSHI N, ISEMURA M. Health-promoting effects of green tea. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2012; 88:88-101. [PMID: 22450537 PMCID: PMC3365247 DOI: 10.2183/pjab.88.88] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Green tea is manufactured from the leaves of the plant Camellia sinensis Theaceae and has been regarded to possess anti-cancer, anti-obesity, anti-atherosclerotic, anti-diabetic, anti-bacterial, and anti-viral effects. Many of the beneficial effects of green tea are related to the activities of (-)-epigallocatechin gallate (EGCG), a major component of green tea catechins. For about 20 years, we have engaged in studies to reveal the biological activities and action mechanisms of green tea and EGCG. This review summarizes several lines of evidence to indicate the health-promoting properties of green tea mainly based on our own experimental findings.
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Affiliation(s)
- Yasuo SUZUKI
- Faculty of Human Life Sciences, Nagoya Keizai University, Inuyama, Japan
| | - Noriyuki MIYOSHI
- Graduate School of Nutritional and Environmental Sciences and Global COE Program, University of Shizuoka, Shizuoka, Japan
| | - Mamoru ISEMURA
- Graduate School of Nutritional and Environmental Sciences and Global COE Program, University of Shizuoka, Shizuoka, Japan
- Correspondence should be addressed: M. Isemura, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan (e-mail: )
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Activation of ERK1/2 and PI3K/Akt by IGF-1 on GAP-43 expression in DRG neurons with excitotoxicity induced by glutamate in vitro. Cell Mol Neurobiol 2011; 32:191-200. [PMID: 21822733 DOI: 10.1007/s10571-011-9746-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 07/28/2011] [Indexed: 10/17/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) is a neurotrophic factor and plays an important role in promoting axonal growth from dorsal root ganglion (DRG) neurons. Whether IGF-1 influences growth-associated protein 43 (GAP-43) expression and activates the extracellular signal-regulated protein kinase (ERK1/2) and the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways in DRG neurons with excitotoxicity induced by glutamate (Glu) remains unknown. In this study, embryonic 15-day-old rat DRG explants were cultured for 48 h and then exposed to IGF-1, Glu, Glu + IGF-1, Glu + IGF-1 + PD98059, Glu + IGF-1 + LY294002, Glu + IGF-1 + PD98059 + LY294002 for additional 12 h. The DRG explants were continuously exposed to growth media as control. The levels of GAP-43 mRNA were detected by real time-PCR analysis. The protein levels of GAP-43, phosphorylated ERK1/2, phosphorylated Akt, total ERK1/2, and total Akt were detected by Western blot assay. GAP-43 expression in situ was determined by immunofluorescent labeling. Apoptotic cell death was monitored by Hoechst 33342 staining. IGF-1 alone increased GAP-43 and its mRNA levels in the absence of Glu. The decreased GAP-43 and its mRNA levels caused by Glu could be partially reversed by the presence of IGF-1. IGF-1 rescued neuronal cell death caused by Glu. Neither the ERK1/2 inhibitor PD98059 nor the PI3K inhibitor LY294002 blocked the effect of IGF-1, but both inhibitors together were effective. To validate the impact of GAP-43 expression by IGF-1, GAP-43 induction was blocked by administration of dexamethasone (DEX). IGF-1 partially rescued the decrease of GAP-43 and its mRNA levels induced by DEX. DEX induced an increase of cell apoptosis. IGF-1 may play an important role in neuroprotective effects on DRG neurons through regulating GAP-43 expression with excitotoxicity induced by Glu and the process was involved in both ERK1/2 and PI3K/Akt signaling pathways.
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Neuregulin-1β Prevents Ca2+ Overloading and Apoptosis Through PI3K/Akt Activation in Cultured Dorsal Root Ganglion Neurons with Excitotoxicity Induced by Glutamate. Cell Mol Neurobiol 2011; 31:1195-201. [DOI: 10.1007/s10571-011-9721-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Accepted: 05/30/2011] [Indexed: 10/18/2022]
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Liu Z, Liu H, Yang X, Xu X, Zhang W, Li Z. Effects of insulin-like growth factor-1 on expression of sensory neuropeptides in cultured dorsal root ganglion neurons in the absence or presence of glutamate. Int J Neurosci 2011; 120:698-702. [PMID: 20942583 DOI: 10.3109/00207454.2010.513463] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) is a neurotrophic factor and plays an important role in promoting axonal growth from dorsal root ganglion (DRG) neurons. Whether IGF-1 could influence expression of sensory neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) of the cultured DRG neurons with excitotoxicity induced by glutamate (Glu) remains unknown. In the present study, primary cultured DRG neurons were used to determine the effects of IGF-1 on expression of SP and CGRP of the neurons with Glu-induced excitotoxicity. The DRG neurons were dissociated and cultured for 48 hr and then exposed to Glu (0.2 mmol/L), IGF-1 (20 nmol/L), and Glu (0.2 mmol/L) plus IGF-1 (20 nmol/L) for additional 12 hr. The DRG neurons were continuously exposed to growth media as control. After that, all the above cultured DRG neurons were processed for detecting SP and CGRP expression by Western blot analysis. The expression of SP and CGRP increased significantly in primary cultured DRG neurons in the presence of IGF-1. The ability of IGF-1 on SP and CGRP expression may play a role in neurogenic inflammation or nociception.
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Affiliation(s)
- Zhen Liu
- Department of Anatomy, Shandong University School of Medicine, Jinan, China
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Kim NH, Jeong HJ, Kim HM. Theanine is a candidate amino acid for pharmacological stabilization of mast cells. Amino Acids 2011; 42:1609-18. [DOI: 10.1007/s00726-011-0847-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Accepted: 02/08/2011] [Indexed: 11/29/2022]
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Gong HC, Yang XD, Liu Z, Xing ZY, Wang HJ, Li ZZ. Regulatory effects of insulin-like growth factor-1 on the expression of sensory neuropeptide mRNAs in cultured dorsal root ganglion neurons with excitotoxicity induced by glutamate. Neurosci Bull 2010; 26:126-32. [PMID: 20332817 DOI: 10.1007/s12264-010-9142-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE To determine the effects of insulin-like growth factor-1 (IGF-1) on the expression of preprotachykinin (PPT) mRNA encoding substance P (SP) and calcitonin gene-related peptide (CGRP) mRNA in cultured dorsal root ganglion (DRG) neurons with excitotoxicity induced by glutamate (Glu). METHODS DRGs were dissected from embryonic day 15 Wistar rats. DRG neurons were dissociated and cultured for 48 h and then exposed to Glu (0.2 mmol/L) or Glu (0.2 mmol/L) plus IGF-1 (5 nmol/L, 10 nmol/L and 20 nmol/L) for 12 h. The DRG neurons in control group were exposed to only growth media throughout the experiment. After that, the living DRG neurons were observed under inverted phase contrast microscope and microphotographs were taken. The expression levels of PPT and CGRP mRNAs were detected by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS IGF-1 could inhibit Glu-induced shortening of neurite. Besides, IGF-1 could significantly increase the levels of PPT mRNA and CGRP mRNA in primary cultured DRG neurons with Glu-induced excitotoxicity, in a dose-dependent manner. CONCLUSION IGF-1 may exert neuroprotective effects on DRG neurons against Glu-induced excitotoxicity, probably through regulating the expression levels of PPT and CGRP mRNAs.
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Affiliation(s)
- Hui-Cui Gong
- Department of Anatomy, Shandong University School of Medicine, Jinan 250012, China
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Dimpfel W, Kler A, Kriesl E, Lehnfeld R. Theogallin and L-theanine as active ingredients in decaffeinated green tea extract: I. electrophysiological characterization in the rat hippocampus in-vitro. J Pharm Pharmacol 2010; 59:1131-6. [PMID: 17725856 DOI: 10.1211/jpp.59.8.0011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
The in-vitro hippocampus slice preparation was used to mimic a physiological situation where nervous tissue is exposed directly to the water soluble extract of green tea and some of its constituents. This investigation provides evidence that L-theanine- and theogallin-enriched decaffeinated green tea extract is able to change the physiological pattern of electrical hippocampus activity in a concentration dependent manner (EC50 3 mg L−1). Of the seven fractions or single components tested (fraction containing all amino acids without L-theanine, fractions containing all amino acids plus L-theanine, glutamic acid, theogallin, its metabolites quinic acid and gallic acid, and L-theanine alone), glutamic acid produced the strongest changes in terms of increased population spike amplitude after single stimuli and increased long-term potentiation, commonly taken as representative for enhancement of spatial and time dependent memory. The presence of theogallin alone shifted the activity in the same direction. Similar results as with theogallin were obtained in the presence of quinic acid. No effect was seen with gallic acid. Opposite changes (decrease of population spike amplitude and attenuated long-term potentiation) were observed in the presence of L-theanine alone. No effects were detected during the addition of the amino acid mixture unless L-theanine was added, leading to a decrease of the responses as observed for the action of L-theanine alone. The results provide evidence for the involvement of several active principles in the action of enriched green tea extract on electrical brain activity. The overall enhancement of hippocampal pyramidal cell responses as observed for the crude extract seems to be due to the combined action of glutamic acid and theogallin (or its presumable metabolite quinic acid), whereas L-theanine seems to have an opposite effect. However, this action was not strong enough to antagonize the effects of glutamic acid and theogallin. The results are in line with the observation that the tested green tea extract improves cognition at concomitant mental relaxation in man.
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Affiliation(s)
- Wilfried Dimpfel
- University of Giessen c/o NeuroCode AG D 35578 Wetzlar, Sportpark-Str. 9, Germany.
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Standardized capsule of Camellia sinensis lowers cardiovascular risk factors in a randomized, double-blind, placebo-controlled study. Nutrition 2009; 25:147-54. [DOI: 10.1016/j.nut.2008.07.018] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 07/02/2008] [Accepted: 07/18/2008] [Indexed: 12/25/2022]
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Affiliation(s)
- Chris D. Meletis
- Executive director of the Institute for Healthy Aging, a nonprofit educational group, in Carson City, Nevada, and an associate professor of natural pharmacology at the National College of Natural Medicine, in Portland, Oregon
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Effects of theanine, a unique amino acid in tea leaves, on memory in a rat behavioral test. Biosci Biotechnol Biochem 2008; 72:1356-9. [PMID: 18460792 DOI: 10.1271/bbb.70669] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We identified an effect of theanine on memory functions in a novel object test. Rats were fed theanine for 3 weeks ad libitum, and then they performed the object test. The theanine-fed group performed search behavior for the novel object in the test session. The results suggest that theanine-fed rats showed improved recognition, and that theanine affected learning and memory.
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Huang F, Liu Z, Liu H, Wang L, Wang H, Li Z. GM1 and NGF modulate Ca2+ homeostasis and GAP43 mRNA expression in cultured dorsal root ganglion neurons with excitotoxicity induced by glutamate. Nutr Neurosci 2008; 10:105-11. [PMID: 18019391 DOI: 10.1080/10284150701406752] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Monosialoganglioside (GM1) has been considered to have a neurotrophic factor-like activity. Nerve growth factor (NGF), a member of the neurotrophin family, is essential for neuronal survival, differentiation and maturation. The aim of the present study was to investigate whether co-administration of GM1 and NGF reverses glutamate (Glu) neurotoxicity in primary cultured rat embryonic dorsal root ganglion (DRG) neurons. DRG neurons were exposed to Glu (2 mmol/1), Glu (2 mmol/1) plus GM1 (10 microg/ml), Glu (2 mmol/l) plus NGF (10 ng/ml), Glu (2 mmol/l) plus GM1 (5 microg/ml) and NGF (5 ng/ml) and then processed for detecting intracellular concentrations of Ca2+ ([Ca2+] i) by confocal laser scanning microscopy and growth-associated protein 43 (GAP43) mRNA by RT-PCR. The fluorescent intensity in Glu plus GM1 and NGF incubated neurons was the lowest as compared with that in other groups. The expression of GAP43 mRNA in Glu plus GM1 and NGF incubated neurons was the highest as compared with that in other groups. These results implicated that GM1 and NGF have synergistic neuroprotective effects on DRG neurons with excitotoxicity induced by Glu in vitro.
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Affiliation(s)
- Fei Huang
- Department of Anatomy, Shandong University School of Medicine, Jinan 250012, People's Republic of China
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Theanine, γ-glutamylethylamide, a unique amino acid in tea leaves, modulates neurotransmitter concentrations in the brain striatum interstitium in conscious rats. Amino Acids 2008; 36:21-7. [DOI: 10.1007/s00726-007-0020-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Accepted: 12/17/2007] [Indexed: 10/22/2022]
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Rogers PJ, Smith JE, Heatherley SV, Pleydell-Pearce CW. Time for tea: mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together. Psychopharmacology (Berl) 2008; 195:569-77. [PMID: 17891480 DOI: 10.1007/s00213-007-0938-1] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Accepted: 09/03/2007] [Indexed: 11/29/2022]
Abstract
RATIONALE Although both contain behaviourally significant concentrations of caffeine, tea is commonly perceived to be a less stimulating drink than coffee. At least part of the explanation for this may be that theanine, which is present in tea but not coffee, has relaxing effects. There is also some evidence that theanine affects cognitive performance, and it has been found to reduce blood pressure in hypertensive rats. OBJECTIVES To study the subjective, behavioural and blood pressure effects of theanine and caffeine administered alone and together, in doses relevant to the daily tea consumption of regular tea drinkers. MATERIALS AND METHODS In a randomised, double-blind, placebo-controlled study, healthy adult participants (n = 48) received either 250-mg caffeine, 200-mg theanine, both or neither of these. They completed ratings of mood, including anxiety, and alertness, and had their blood pressure measured before and starting 40 min after drug administration. Anxiety was also assessed using a visual probe task. RESULTS Caffeine increased self-rated alertness and jitteriness and blood pressure. Theanine antagonised the effect of caffeine on blood pressure but did not significantly affect jitteriness, alertness or other aspects of mood. Theanine also slowed overall reaction time on the visual probe task. CONCLUSIONS Theanine is a physiologically and behaviourally active compound and, while it is unclear how its effects might explain perceived differences between tea and coffee, evidence suggests that it may be useful for reducing raised blood pressure.
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Affiliation(s)
- Peter J Rogers
- Department of Experimental Psychology, University of Bristol, 12a Woodland Road, Bristol, BS8 1TU, UK.
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