Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study.

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.

Effect of L-theanine on glutamatergic function in patients with schizophrenia.

Objectives: Glutamatergic dysfunction in the brain has been implicated in the pathophysiology of schizophrenia. Previous studies suggested that L-theanine affects the glutamatergic neurotransmission and ameliorates symptoms in patients with schizophrenia. The aims of the present study were twofold: to examine the possible effects of L-theanine on symptoms in chronic schizophrenia patients and to evaluate the changes in chemical mediators, including glutamate + glutamine (Glx), in the brain by using 1H magnetic resonance spectroscopy (MRS).

Effect of L-theanine on sensorimotor gating in healthy human subjects.

Aim: l-Theanine (N-ethyl-l-glutamine) is an amino acid uniquely found in green tea. Growing evidence has suggested the possible effects of l-theanine on cognition. Previously, we found that l-theanine attenuates MK-801-induced deficit in prepulse inhibition (PPI) in mice.

Anti-stress effect of theanine on students during pharmacy practice: positive correlation among salivary α-amylase activity, trait anxiety and subjective stress.

Purpose: Theanine, an amino acid in tea, has significant anti-stress effect on experimental animals under psychosocial stress. Anti-stress effect of theanine on humans was evaluated in 5th-year university students during pharmacy practice.

Method: The study design was a single-blind group comparison and participants (n=20) were randomly assigned to theanine or placebo groups.

Syntheses of mucin-type O-glycopeptides and oligosaccharides using transglycosylation and reverse-hydrolysis activities of Bifidobacterium endo-alpha-N-acetylgalactosaminidase.

Endo-alpha-N-acetylgalactosaminidase catalyzes the release of Galbeta1-3GalNAc from the core 1-type O-glycan (Galbeta1-3GalNAcalpha1-Ser/Thr) of mucin glycoproteins and synthetic p-nitrophenyl (pNP) alpha-linked substrates. Here, we report the enzymatic syntheses of core 1 disaccharide-containing glycopeptides using the transglycosylation activity of endo-alpha-N-acetylgalactosaminidase (EngBF) from Bifidobacterium longum. The enzyme directly transferred Galbeta1-3GalNAc to serine or threonine residues of bioactive peptides such as PAMP-12, bradykinin, peptide-T and MUC1a when Galbeta1-3GalNAcalpha1-pNP was used as a donor substrate.

Characterization of two different endo-alpha-N-acetylgalactosaminidases from probiotic and pathogenic enterobacteria, Bifidobacterium longum and Clostridium perfringens.

Endo-alpha-N-acetylgalactosaminidase (endo-alpha-GalNAc-ase) catalyzes the hydrolysis of the O-glycosidic bond between alpha-GalNAc at the reducing end of mucin-type sugar chains and serine/threonine of proteins to release oligosaccharides. Previously, we identified the gene engBF encoding endo-alpha-GalNAc-ase from Bifidobacterium longum, which specifically released the disaccharide Gal beta 1-3GalNAc (Fujita K, Oura F, Nagamine N, Katayama T, Hiratake J, Sakata K, Kumagai H, Yamamoto K. 2005.