Green tea has been consumed as the most popular drink in East Asia for centuries, and is believed to have a wide range of health benefits. L-Theanine, the major component of the free amino acids in green tea, has been reported to display neuronal protection and tumor inhibition in vitro, but its physiological effects on animal development and behavior remain elusive. In this report, we used Dro...

Theanine is the major amino acid present in Camellia sinensis or green tea. A method for determining theanine in its native state using liquid chromatography with positive-mode electrospray ionization mass spectrometric detection was developed. Quantitation of theanine was achieved using theanine-[(2)H(5)] as an internal standard. This approach was utilized on different green tea matrix materia...

umami (the fifth taste sensation)-component of tea and is contained 2—3% in tea leaves. Theanine is a glutamate derivative and is used extensively as supplements and beverages, because it has a brain nerve function such as a relaxing effect due to inducing alpha waves. But there are few reports about pharmacological action of theanine in comparison with catechin or caffeine, major tea component...

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 w...

L-Theanine has favorable physiological effects in terms of human health, but the mechanisms that transport it to its target organs or cells are not completely defined. To identify the major transport mechanisms of L-theanine, we screened for candidate transporters of L-3H-theanine in several mammal cell lines that intrinsically express multiple transporters with various specificities. All of th...

As a natural analogue of glutamate, l-theanine is the unique amino acid derivative in green tea. Although its underlining mechanisms are not yet clear, it has been suggested that l-theanine treatment may prove beneficial to patients with neurodegenerative diseases. In this study, we investigated the neuroprotective effect and its mechanism of l-theanine in an in vitro model of Alzheimer's disea...

To date quality and selling price of a tea mainly depends on its flavour, taste and texture but not on its medicinal properties though a Chinese scientist in 780 AD suggested and acclaimed tea as a divine remedy and supreme gift of God for preserving mental tranquillity. Different studies have been showed that L-theanine is the key component of tea which can make us mentally calm, cool and rela...

The effect of theanine, one of the components of green tea, on the blood pressure and brain 5-hydroxyindoles in spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) was investigated by intraperitoneally administering theanine. The effect of glutamine, which is structurally similar to theanine, was also examined. When SHR were injected with various amounts of theanine (0, 500, 1000,...

Forty weanling piglets (5.6±0.5 kg and 26 to 30 d of age) were used in a 28-d experiment to determine the effects of βglucan from Paenibacillus polymyxa and L-theanine on growth performance. Piglets were randomly allotted to four groups (n = 10, 2 animals per pen) provided with the basal feed (control), β-glucan 400 mg/kg feed, L-theanine 80 mg/kg feed or β-glucan plus l-theanine (combination o...

Theanine is a peculiar amino acid existing in green tea leaves, which was previously indicated to enhance the antitumor activity of doxorubicin. In the present study, the effect of combination of theanine with doxorubicin against hepatic metastasis of M5076 ovarian sarcoma was investigated. The primary tumor was significantly reduced by the combined treatment on M5076 transplanted (s.c.) mice. ...