title: Effects of epigallocatechin-3-gallate on behavioral impairments induced by psychological stress in rats.
abstract: This study was conducted to explore the effects of epigallocatechin-3-gallate (EGCG) on cognitive performances in psychological stress rats. An animal model of psychological stress was developed by restraint stress for three weeks. Male Wistar rats were randomly assigned to four groups as follows: normal control group, stress control group and two stress groups with green tea polyphenols (GTPs) and EGCG modulation, respectively. The changes of behavioral performances of rats were examined by the open-field test and step-through test. Results showed that behavioral performances of stress control group were changed abnormally, and they were improved in GTPs and EGCG modulation groups. In addition, plasma levels of cortisol, dopamine, norepinephrine, 5-hydroxytryptamine, interleukin-6 and interleukin-2 were detected. Stress control group had increased contents of cortisol, interleukin-6 and interleukin-2, and meanwhile had declined levels of 5-hydroxytryptamine and catecholamines. These changes in GTPs and EGCG modulation groups were similar to that of the normal control group. The expressions of metallothioneins in the hippocampus were detected by reverse transcription polymerase chain reaction. In contrast with the normal control group, their expressions in all the three stress groups were enhanced clearly. The results suggested that GTPs and EGCG modulation could improve the cognitive impairments induced by psychological stress. The related mechanisms may be involved with the changes of catecholamines, 5-hydroxytryptamine, cytokines and expressions of metallothioneins.
authors.affiliation: Department of Nutrition, Institute of Health and Environmental Medicine, Tianjin 300050, China. tjchenwq@sohu.com
authors.forename: Wei-Qiang
authors.initials: WQ
authors.lastname: Chen
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Zhao
authors.forename: Dong-Lan
authors.initials: DL
authors.lastname: Wang
authors.forename: Shu-Tian
authors.initials: ST
authors.lastname: Li
authors.forename: Yue
authors.initials: Y
authors.lastname: Hou
authors.forename: Yan
authors.initials: Y
authors.lastname: Hong
authors.forename: Yi-Yong
authors.initials: YY
authors.lastname: Cheng
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D002395:Catecholamines / Q000097:blood; D005786:Gene Expression Regulation / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood; D007376:Interleukin-2 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism; D008517:Phytotherapy; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000097:blood; D013315:Stress, Psychological / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology*
chemical_list: D002395:Catecholamines; D007376:Interleukin-2; D015850:Interleukin-6; D012701:Serotonin; D002392:Catechin; D008668:Metallothionein; C045651:epigallocatechin gallate; D006854:Hydrocortisone