title: Antidepressant-like effects of L-theanine in the forced swim and tail suspension tests in mice.
abstract: L-theanine (γ-glutamylethylamide), an amino acid component of green tea, has been shown to reduce mental and physical stress, and to improve memory function. In this study, the antidepressant effect of L-theanine was investigated in mice using the forced swim test, tail suspension test, open-field test and reserpine test. L-theanine produced an antidepressant-like effect, since the administration of L-theanine at doses of 1, 4 and 20 mg/kg for 10 successive days significantly reduced the immobility time in both the forced swim test and tail suspension test, compared with the control group, without accompanying changes in ambulation in the open-field test. Moreover, L-theanine significantly antagonized reserpine-induced ptosis and hypothermia. Taken together, these results indicate that L-theanine possessed an antidepressant-like effect in mice, which may be mediated by the central monoaminergic neurotransmitter system.
authors.affiliation: School of Pharmacy, Xuzhou Medical College, 84 West Huai'hai Road, Xuzhou, Jiangsu 221002, China.
authors.forename: Cui
authors.initials: C
authors.lastname: Yin
authors.forename: Lingshan
authors.initials: L
authors.lastname: Gou
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Yin
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Genguang
authors.initials: G
authors.lastname: Jia
authors.forename: Xuemei
authors.initials: X
authors.lastname: Zhuang
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects*; D005971:Glutamates / Q000494:pharmacology*; D019417:Hindlimb Suspension; D007035:Hypothermia / Q000188:drug therapy; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D013315:Stress, Psychological / Q000188:drug therapy*; D013550:Swimming
chemical_list: D000928:Antidepressive Agents; D005971:Glutamates; C026166:theanine