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Keiko Unno, Ayane Hara, Aimi Nakagawa, Kazuaki Iguchi, Megumi Ohshio, Akio Morita, Yoriyuki Nakamura
BACKGROUND: Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the anti-stress effects of drinking green tea have not yet been elucidated. HYPOTHESIS/PURPOSE: The present study aimed to explore anti-stress effects of green tea and roles of tea components in a mouse model of psychosocial stress. STUDY DESIGN: We examined anti-stress effects of three types of green teas, theanine-rich "Gyokuro", standard "Sencha", and Sencha with lowered caffeine (low-caffeine green tea)...
November 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Dong Bok Jeon, Young Shin Hong, Ga Hyun Lee, Yu Min Park, Cheong Mi Lee, Eun Yeong Nho, Ji Yeon Choi, Nargis Jamila, Naeem Khan, Kyong Su Kim
Tea contains characteristic volatile organic compounds, polyphenols, caffeine and catechins, and is therefore among the most widely consumed beverages all over the world. In this study, fresh Jukro tea leaves collected from Damyang-gun (Jeollanam-do) at 40, 60 and 90day growth stages, were semi-fermented. The volatile organic compounds (VOCs) were extracted by simultaneous distillation-solvent extraction (SDE) and analyzed by gas chromatography/mass spectrometry (GC/MS). Catechins, caffeine and theanine were analyzed by high performance liquid chromatography (HPLC)...
March 15, 2017: Food Chemistry
Mika Takeshima, Ikuko Miyazaki, Shinki Murakami, Taizo Kita, Masato Asanuma
l-Theanine (γ-glutamylethylamide), a component of green tea, is considered to have regulatory and neuroprotective roles in the brain. The present study was designed to determine the effect of l-theanine on excess dopamine-induced neurotoxicity in both cell culture and animal experiments. The primary cultured mesencephalic neurons or co-cultures of mesencephalic neurons and striatal astrocytes were pretreated with l-theanine for 72 h, and then treated with excess dopamine for further 24 h. The cell viability of dopamine neurons and levels of glutathione were evaluated...
September 2016: Journal of Clinical Biochemistry and Nutrition
Huajun Zheng, Dejiang Ni, Zhi Yu, Pei Liang
A kind of graphene oxide/silver (GO/Ag) nanocomposites with high Surface enhanced Raman scattering (SERS) activity were fabricated via a facile and green liquid phase reduction method. The synthesized materials were characterized in detail using various microscopic and spectroscopic techniques. In this method, the GO sheets worked as a holder which makes silver nanoparticles (AgNPs) aggregate to a particular morphology, and under a suitable dosage of silver ions, well-dispersed AgNPs on the surface of GO were obtained, which could generate more "hot spots" of SERS...
February 15, 2017: Food Chemistry
Peiling Ben, Zhengping Zhang, Yanyan Zhu, Aiying Xiong, Yanhong Gao, Jianyun Mu, Zhimin Yin, Lan Luo
Cadmium (Cd) has long been known to induce neurological degenerative disorders. We studied effects of l-theanine, one of the major amino acid components in green tea, on Cd-induced brain injury in mice. Male ICR mice were intraperitoneally injected with l-theanine (100 or 200mg/kg/day) or saline and after one hour these mice were orally administrated with CdCl2 (3.75-6mg/kg). The treatment was conducted for 8 weeks. l-Theanine significantly reduced Cd level in the mouse brain and plasma. Cd-induced neuronal cell death in the mouse cortex and hippocampus were apparently inhibited by l-theanine treatment...
September 17, 2016: Neurotoxicology
Maria Ofitserova, Sareeta Nerkar
An HPLC method with postcolumn derivatization was developed and validated for the determination of theanine content in tea dietary ingredients and supplements. A variety of common commercially available supplement forms such as powders, liquid tinctures, tablets, softgels, and gelcaps, as well as three National Institute of Standards and Technology Camellia sinensis Standard Reference Materials were investigated in the study. A simple extraction procedure using citrate buffer at pH 2.2 allowed for the analysis of theanine without additional cleanup or concentration steps, even at low ppm levels...
September 15, 2016: Journal of AOAC International
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
Rubia C G Corrêa, Rosane M Peralta, Charles W I Haminiuk, Giselle Maria Maciel, Adelar Bracht, Isabel C F R Ferreira
Aging is an inevitable process influenced by genetic, lifestyle and environmental factors. Indirect evidence shows that several phytochemicals can have anti-aging capabilities, although direct evidence in this field is still limited. This report aims to provide a critical review on aspects related to the use of novel phytochemicals as anti-aging agents, to discuss the obstacles found when performing most anti-aging study protocols in humans, and to analyze future perspectives. In addition to the extensively studied resveratrol, epicatechin, quercetin and curcumin, new phytochemicals have been reported to act as anti-aging agents, such as the amino acid L-theanine isolated from green tea, and the lignans arctigenin and matairesinol isolated from Arctium lappa seeds...
September 13, 2016: Critical Reviews in Food Science and Nutrition
Jiannan Liu, Yuping Sun, Huarong Zhang, Dexin Ji, Fei Wu, Huihui Tian, Kun Liu, Ying Zhang, Benhao Wu, Guoying Zhang
Cervical cancer is the third most prevalent cancer among women worldwide. Theanine from tea and its derivatives show some anticancer activities. However, the role of theanine and its derivatives against human cervical cancer and the molecular mechanisms of action remain unclear. Thus, in this study, we aim to investigate the anticancer activities and underlying mechanisms of theanine and a theanine derivative, ethyl 6-bromocoumarin-3- carboxylyl L-theanine (TBrC), against human cervical cancer. In vitro and in vivo assays for cancer cell growth and migration have confirmed the inhibition of the cell growth and migration by TBrC and theanine in highly-metastatic human cervical cancer...
September 6, 2016: European Journal of Pharmacology
Chun-Fang Li, Yan-Xia Xu, Jian-Qiang Ma, Ji-Qiang Jin, Dan-Juan Huang, Ming-Zhe Yao, Chun-Lei Ma, Liang Chen
BACKGROUND: The new shoots of the albino tea cultivar 'Anji Baicha' are yellow or white at low temperatures and turn green as the environmental temperatures increase during the early spring. 'Anji Baicha' metabolite profiles exhibit considerable variability over three color and developmental stages, especially regarding the carotenoid, chlorophyll, and theanine concentrations. Previous studies focused on physiological characteristics, gene expression differences, and variations in metabolite abundances in albino tea plant leaves at specific growth stages...
2016: BMC Plant Biology
Guoying Zhang, Zheng Li, Xiaochun Wan, Ying Zhang, Rongqin Zhu, Zhenzhen Liu, Dexin Ji, Huarong Zhang, Fei Wu, Huihui Tian, Kun Liu, Benhao Wu
To explore the potential of theanine against cancer, we have studied the anticancer activities of theanine from tea and its semisynthesized derivative, (R)-2-(6,8-dibromo-2-oxo-2H-chromene-3-carboxamido)-5-(ethylamino)-5-oxopentanoic ethyl ester (DTBrC), in in vitro, ex vivo, and in vivo models of human hepatocellular carcinoma (HHC). Theanine and DTBrC displayed inhibitory effects on the growth and migration of HHC cells in vitro, ex vivo, and in vivo. Theanine and DTBrC significantly enhanced the repression of HHC cell growth in combination with anticancer drug pirarubicin...
September 21, 2016: Journal of Agricultural and Food Chemistry
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
Shinsuke Hidese, Miho Ota, Chisato Wakabayashi, Takamasa Noda, Hayato Ozawa, Tsutomu Okubo, Hiroshi Kunugi
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...
July 11, 2016: Acta Neuropsychiatrica
Takashi Tsuchiya, Hiroshi Honda, Masaya Oikawa, Tetsuya Kakita, Atsushi Oyama, Hidekazu Oishi, Katsuyuki Tochikubo, Takanao Hashimoto, Shigekazu Kurihara, Tetsuro Shibakusa, Takashi Kayahara
BACKGROUND: Nutritional therapy is used to reduce the adverse events (AEs) of anticancer drugs. Here, we determined whether the amino acids cystine and theanine, which provide substrates for glutathione, attenuated the AEs of S-1 adjuvant chemotherapy. METHODS: Patients scheduled to receive S-1 adjuvant chemotherapy were randomized to the C/T or the control groups. The C/T group received 700 mg cystine and 280 mg theanine orally 1 week before the administration of S-1, which then continued for 5 weeks...
June 15, 2016: International Journal of Clinical Oncology
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
Jianwei Liu, Qunfeng Zhang, Meiya Liu, Lifeng Ma, Yuanzhi Shi, Jianyun Ruan
The sensory quality of green tea changes greatly within a single spring season, but the mechanism is not clearly elucidated. Young shoots of the early, middle, and late spring season were subjected to metabolite profiling using gas chromatography-time-of-flight mass spectrometry (TOF/MS) and ultraperformance liquid chromatography-quadrupole-TOF/MS. Multivariate analyses revealed largely different metabolite phenotypes in young shoots among different periods. The contents of amino acids decreased, whereas carbohydrates, flavonoids and their glycosides, tricarboxylic acid cycle, and photorespiration pathways were strongly reinforced in the late spring season, which were well reflected in the sensory quality of made teas...
April 27, 2016: Journal of Agricultural and Food Chemistry
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
Wu Bi, Chunnian He, Yunyun Ma, Jie Shen, Linghua Harris Zhang, Yong Peng, Peigen Xiao
To find novel functional beverages from folk teas, 33 species of frequently used non-Camellia tea (plants other than Camellia) were collected and compared with Camellia tea (green tea, pu-erh tea and black tea) for the first time. Data are reported here on the quantities of 20 free amino acids (FAAs) and three purine alkaloids (measured by UHPLC), total polyphenols (measured by Folin-Ciocalteu assay), and antioxidant activity (DPPH). The total amounts of FAAs in non-Camellia tea (0.62-18.99 mg/g) are generally less than that of Camellia tea (16...
March 2016: Acta Pharmaceutica Sinica. B
Sumit Jamwal, Puneet Kumar
L-theanine is unique amino acid which readily crosses blood brain barrier and possesses neuroprotective potential against neurodegenerative disorders including Huntington disease (HD). HD is characterized by selective loss of GABAergic medium spiny neurons. 3-nitropropionic acid (3-NP) induces a spectrum of HD-like neuropathology in rat striatum and widely used as experimental tool to study HD. Therefore, the present study was intended to investigate the effect of L-theanine against 3-NP-induced striatal toxicity and to explore its possible mechanism...
March 9, 2016: Molecular Neurobiology
Chengjian Li, Haiou Tong, Qiongxian Yan, Shaoxun Tang, Xuefeng Han, Wenjun Xiao, Zhiliang Tan
BACKGROUND This study aimed to investigate the regulatory effects of L-theanine on secretion of immune cytokines, hormones, and neurotransmitters, and mRNA expression of phospholipase C (PLC) in rats, and to explore its regulatory mechanism in immune function. MATERIAL AND METHODS Sixty-four Sprague-Dawley rats received daily intragastric infusion of different doses of L-theanine solution [0, 50 (LT), 200 (MT), and 400 (HT) mg/kg BW]. Cytokines, immunoglobulins, and hormones in the serum, neurotransmitters, and mRNA expression of PLC in the relevant tissues were assayed...
2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
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