The ameliorative effect of L-theanine on chronic unpredictable mild stress-induced depression in rats and the possible mechanism were investigated. The model of chronic unpredictable mild stress (CUMS) rats was established, and the antidepressant effect of L-theanine was evaluated through sucrose preference test, open-field test and light/dark box test. Then, the contents of the 5-hydroxytryptamine (5-HT), noradrenaline (NA), adrencocorticotropic hormone (ACTH) and corticosterone (CORT) in the hippocampus and prefrontal cortex were determined by ELISA analysis for exploring the underlying mechanism. Also, the enzyme activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in the serum and hippocampus were measured. The results showed that, compared with control group, the percentage of sucrose preference, the numbers of crossing and rearing, and the number of entries into light box and total duration time in model group were very significantly lower, which demonstrated the model was successfully established. Compared to the model group, the behavior of CUMS-induced depression was significantly ameliorated by the administration of L-theanine, especially that with high dose. Meanwhile, L-theanine could significantly increase the contents of 5-HT and NA, decrease the contents of ACTH and CORT in the hippocampus and prefrontal cortex of rats, increase the activities of SOD and GSH-Px in serum and prefrontal cortex, which further demonstrated the antidepressant function of L-theanine. The underlying mechanism might be mainly related to the enhanced secretion of monoamine neurotransmitter.
PENG Bin
,
LIU Zhonghua
,
LIN Yong
,
LIN Haiyan
,
HUANG Jian'an
. The Ameliorative Effect of L-theanine on Chronic Unpredictable Mild Stress-induced Depression in Rats[J]. Journal of Tea Science, 2014
, 34(4)
: 355
-363
.
DOI: 10.13305/j.cnki.jts.2014.04.006
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