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Caffeine L-Theanine

Xin Li, Golam J Ahammed, Zhi-Xin Li, Lan Zhang, Ji-Peng Wei, Chen Shen, Peng Yan, Li-Ping Zhang, Wen-Yan Han
Summer grown green tea is less popular due to bitterness and high astringency, which are attributed to high levels of tea polyphenols (TP) and low levels of amino acids (AA) in tea leaves (Camellia sinensis L.). Brassinosteroids (BRs), a group of steroidal plant hormones can regulate primary and secondary metabolism in a range of plant species under both normal and stress conditions. However, specific effects of BRs on the photosynthesis of tea plants and the quality of summer green tea are largely unknown...
2016: Frontiers in Plant Science
Yuchen Li, Changsong Chen, Yusheng Li, Zhaotang Ding, Jiazhi Shen, Yu Wang, Lei Zhao, Meng Xu
BACKGROUND: The tea plant, Camellia sinensis (L.) O. Kuntz, is a perennial woody plant widely cultivated for the production of a popular non-alcoholic beverage. To rapidly identify and evaluate two different color tea varieties (yellowish and purplish), the main phenotypic traits and quality components were tested in this study. Then the metabolic profiles of tea shoots and leaves were analyzed using LC-MS/MS. RESULTS: The yellowish variation had higher active level in catechins metabolism, and contents of luteolin and kaempferol 3-α-D-glucoside were much higher than others...
July 13, 2016: Journal of the Science of Food and Agriculture
Weidong Wang, Huahong Xin, Mingle Wang, Qingping Ma, Le Wang, Najeeb A Kaleri, Yuhua Wang, Xinghui Li
The tea plant [Camellia sinensis (L.) O. Kuntze] is an important commercial crop rich in bioactive ingredients, especially catechins, caffeine, theanine and other free amino acids, which the quality of tea leaves depends on. Drought is the most important environmental stress affecting the yield and quality of this plant. In this study, the effects of drought stress on the phenotype, physiological characteristics and major bioactive ingredients accumulation of C. sinensis leaves were examined, and the results indicated that drought stress resulted in dehydration and wilt of the leaves, and significant decrease in the total polyphenols and free amino acids and increase in the total flavonoids...
2016: Frontiers in Plant Science
Klára Boros, Nikoletta Jedlinszki, Dezső Csupor
BACKGROUND: Caffeine and L-theanine are pharmacologically important constituents of tea, especially due to their effects on the central nervous system. The effects of these two compounds are opposite: While caffeine is a well-known stimulant, theanine has a relaxing effect. Tea processing may influence the caffeine and theanine content of tea leaves. OBJECTIVE: The aim of our work was to quantify these constituents from a set of commercial products to reveal the possible correlations of caffeine and theanine content and processing methods...
January 2016: Pharmacognosy Magazine
Tânia R Dias, Marco G Alves, Susana Casal, Branca M Silva, Pedro F Oliveira
Caffeine, epigallocatechin-3-gallate (EGCG) and L-theanine are the major components of tea (Camellia sinensis L.) and the main representatives of the classes of methylxanthines, catechins and free amino acids present in this beverage. There are many studies reporting tea's health benefits, however it is not clear if those effects are mediated by a single component or a synergistic action. This study aimed to evaluate the individual and synergistic effects of tea's major components on rat epididymal spermatozoa survival and oxidative profile during 3-day storage at room temperature (RT)...
March 2016: Food & Function
Chanaka N Kahathuduwa, Tharaka L Dassanayake, A M Tissa Amarakoon, Vajira S Weerasinghe
Objective l-theanine is a constituent of tea which is claimed to enhance cognitive functions. We aimed to determine whether theanine and theanine-caffeine combination have acute positive effects on cognitive and neurophysiological measures of attention, compared to caffeine (a positive control) and a placebo in healthy individuals. Design In a placebo-controlled, five-way crossover trial in 20 healthy male volunteers, we compared the effects of l-theanine (200 mg), caffeine (160 mg), their combination, black tea (one cup) and a placebo (distilled water) on cognitive (simple [SVRT] and recognition visual reaction time [RVRT]) and neurophysiological (event-related potentials [ERPs]) measures of attention...
February 11, 2016: Nutritional Neuroscience
Jianchang Jin, Hao Ying, Meirong Huang, Qizhen Du
The Chinese commonly believe that tea helps maintain clear vision. This viewpoint has been recorded in Chinese medical books also. The key bioactive compounds in green tea leaves, (-)-epigallocatechin gallate (EGCG), L-theanine (theanine) and caffeine, were investigated for their abilities to attenuate the injury of retinal ganglion cells (RGC-5) induced by H2O2 and ultraviolet radiation. Theanine and caffeine promoted cell growth while concentrations of EGCG greater than 10μg/ml inhibited cell growth. The nine and caffeine both protected RGC-5 cells from injury as well as enhanced their recovery, while EGCG only protected the cells from injury and did not help them to recover...
November 2015: Pakistan Journal of Pharmaceutical Sciences
Duygu Türközü, Nevin Şanlier
Tea has been a very popular beverage around the world for centuries. The reason that it is delicious, enabling hydration, showing warming and relaxing effect can be mentioned why it is consumed so much in addition to its prominent health effects. Although the catechins and caffeine are the primary bioactive components that are related with the health effects of the tea, the health effects of theanine amino acid, which is a non-proteinic amino acid special to tea, has become prominent in recent years. It has been known that the theanine amino acid in tea has positive effects especially on relaxing, cognitive performance, emotional status, sleep quality, cancer, cardiovascular diseases, obesity and common cold...
July 20, 2015: Critical Reviews in Food Science and Nutrition
Alemu Tadesse, Ariaya Hymete, Adnan A Bekhit, Salahuddin Farooq Mohammed
OBJECTIVE: In this study four tea samples Gumero black, Wushwush black and Wushwush green from Agri- Ceft Plc and East Africa black tea leaves from East African Agribusiness Plc were investigated for total polyphenols, caffeine, catechin and L-theanine content. MATERIALS AND METHODS: The aqueous extracts were investigated for their antioxidant and antileishmanial property and effect on amphotericin B, miltefocine and sodium stibogluconate, the commonly used antileishmanial drugs...
June 2015: Pharmacognosy Research
Wei-Wei Deng, Hiroshi Ashihara
Caffeine (1,3,7-trimethyl xanthine) and theanine (γ-glutamyl-L-ethylamide) are the major nitrogen-containing secondary metabolites in tea leaves. The aim of the present study was to elucidate the relative concentration and amounts of these compounds and the de novo biosynthetic activity in different parts of tea seedlings grown for 27-, 106- and 205 days. The results indicated that caffeine and its biosynthetic activity occur only in leaves and stems, while theanine is distributed in all organs, including roots...
May 2015: Natural Product Communications
Ana R Nunes, Marco G Alves, Paula I Moreira, Pedro F Oliveira, Branca M Silva
Diabetes mellitus (DM) is a metabolic disease that is rapidly increasing and has become a major public health problem. Type 2 DM (T2DM) is the most common type, accounting for up to 90-95% of the new diagnosed DM cases. The brain is very susceptible to glucose fluctuations and hyperglycemia-induced oxidative stress (OS). It is well known that DM and the risk of developing neurodegenerative diseases are associated. Tea, Camellia sinensis L., is one of the most consumed beverages. It contains several phytochemicals, such as polyphenols, methylxanthines (mainly caffeine) and L-theanine that are often reported to be responsible for tea's health benefits, including in brain...
December 2014: Current Neuropharmacology
F L Dodd, D O Kennedy, L M Riby, C F Haskell-Ramsay
RATIONALE: Evidence suggests interactive effects of the tea components caffeine and L-theanine on behaviour, yet no data exists exploring the impact of the two on cerebral blood flow (CBF). OBJECTIVES: The current placebo-controlled, double-blind, counterbalanced, crossover study examined the effects of caffeine and L-theanine on CBF and extended previous cognitive and mood findings by using lower doses than previous studies of a similar methodology, which more closely reflect the ratios present in tea...
July 2015: Psychopharmacology
Vanessa R Conde, Marco G Alves, Pedro F Oliveira, Branca M Silva
The leaves of Camellia sinensis (L.) are the source of tea, the second most consumed beverage worldwide. Tea contains several chemical compounds such as polyphenols (mainly catechins), caffeine, theophylline, L-theanine, among many others. Polyphenolic compounds are the main responsible for its significant antioxidant properties and anticarcinogenic potential. Bladder cancer is one of the most common types of cancer, and its progression and onset are thought to be controlled by dietary and lifestyle factors...
December 3, 2014: Anti-cancer Agents in Medicinal Chemistry
Vanessa R Conde, Marco G Alves, Pedro F Oliveira, Branca M Silva
The leaves of Camellia sinensis (L.) are the source of tea, the second most consumed beverage worldwide. Tea contains several chemical compounds such as polyphenols (mainly catechins), caffeine, theophylline, L-theanine, among many others. Polyphenolic compounds are mainly responsible for its significant antioxidant properties and anticarcinogenic potential. Bladder cancer is one of the most common types of cancer, and its progression and onset are thought to be controlled by dietary and lifestyle factors. Epidemiological studies showed that the regular consumption of tea can be a preventive factor for this type of cancer, and several in vivo and in vitro studies reported that tea and its components may interfere in the cancer cells' signaling, preventing the bladder tumor progression...
2015: Anti-cancer Agents in Medicinal Chemistry
Lindsay B Baker, Ryan P Nuccio, Asker E Jeukendrup
Performance in many sports is at least partially dependent on motor control, coordination, decision-making, and other cognitive tasks. This review summarizes available evidence about the ingestion of selected nutrients or isolated compounds (dietary constituents) and potential acute effects on motor skill and/or cognitive performance in athletes. Dietary constituents discussed include branched-chain amino acids, caffeine, carbohydrate, cocoa flavanols, Gingko biloba, ginseng, guarana, Rhodiola rosea, sage, L-theanine, theobromine, and tyrosine...
December 2014: Nutrition Reviews
David A Camfield, Con Stough, Jonathon Farrimond, Andrew B Scholey
A systematic review and meta-analysis was conducted on 11 randomized placebo-controlled human studies of acute effects of tea constituents L-theanine and epigallocatechin gallate, administered alone or in combination with caffeine, on cognitive function and mood. The outcome measures of mood were alertness, calmness, and contentedness, derived from the Bond-Lader scales, and state anxiety, from the State-Trait Anxiety Inventory. Cognitive measures assessed were attentional switch, intersensory attention, and rapid visual information processing...
August 2014: Nutrition Reviews
Peigen Yu, Angelin Soo-Lee Yeo, Mei-Yin Low, Weibiao Zhou
Thirty-nine non-volatile compounds in seven ready-to-drink (RTD) green tea samples were analysed and quantified using liquid chromatography. Taste reconstruction experiments using thirteen selected compounds were conducted to identify the key non-volatile tastants. Taste profiles of the reconstructed samples did not differ significantly from the RTD tea samples. To investigate the taste contribution and significance of individual compounds, omission experiments were carried out by removing individual or a group of compounds...
July 15, 2014: Food Chemistry
Ai Yoto, Mao Motoki, Sato Murao, Hidehiko Yokogoshi
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...
2012: Journal of Physiological Anthropology
Laura E Wise, Ishani D Premaratne, Thomas F Gamage, Aron H Lichtman, Larry D Hughes, Louis S Harris, Mario D Aceto
l-theanine, 2-amino-4-(ethylcarbamoyl) butyric acid, an amino acid found in green tea (Camellia sinensis), is sold in the United States as a dietary supplement to reduce stress and improve cognition and mood. The observations that l-theanine has been shown to inhibit caffeine's stimulatory effects and that caffeine produces precipitated withdrawal signs in opioid-addicted monkeys and some opioid withdrawal signs in some normal monkeys, suggest that l-theanine may suppress opioid withdrawal signs. Additionally, l-theanine produces anxiolytic effects in humans indicating that it has anti-anxiety properties...
December 2012: Pharmacology, Biochemistry, and Behavior
John J Foxe, Kristen P Morie, Peter J Laud, Matthew J Rowson, Eveline A de Bruin, Simon P Kelly
Caffeine and L-theanine, both naturally occurring in tea, affect the ability to make rapid phasic deployments of attention to locations in space as reflected in behavioural performance and alpha-band oscillatory brain activity (8-14 Hz). However, surprisingly little is known about how these compounds affect an aspect of attention that has been more popularly associated with tea, namely vigilant attention: the ability to maintain focus on monotonous tasks over protracted time-periods. Twenty-seven participants performed the Sustained Attention to Response Task (SART) over a two-hour session on each of four days, on which they were administered caffeine (50 mg), theanine (100 mg), the combination, or placebo in a double-blind, randomized, cross-over fashion...
June 2012: Neuropharmacology
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