Antidepressant-like effects of water extract of Gastrodia elata Blume in rats exposed to unpredictable chronic mild stress via modulation of monoamine regulatory pathways.
BACKGROUND
Gastrodia elata Blume (GE) is a traditional herbal medicine belonging to the Orchidaceae family, and has been used to manage neurological disorders for centuries. We have previously reported that its water extract (WGE) could improve the depressive-like behaviours in the forced swimming test (FST), an animal model of depression.


OBJECTIVE
To investigate the antidepressant-like effects of WGE in rats exposed to unpredictable chronic mild stress (UCMS) model, and to explore its possible molecular mechanisms.


METHODS
UCMS rats were orally administered with WGE (0.5g/kg body weight) daily within the 4 weeks UCMS procedure. The sucrose preference test and the open field test were conducted to assess anhedonia and spontaneous behaviours, respectively. The cerebral turnover rates of monoamine neurotransmitters and the serum corticosterone levels were measured. In vitro direct and indirect monoamine oxidase A (MAO-A) inhibitory assays were employed to assess the possible antidepressant-like mechanisms of WGE (0.5mg/mL) and its major component, gastrodin (GAS, 15, 30 and 60μg/mL). Western blot was used to examine the expression of protein related to monoamine regulation, such as MAO-A and tyrosine hydroxylase (TH).


RESULTS
WGE significantly reversed the sucrose preference and other abnormal behaviours induced by 4 weeks of UCMS. WGE significantly restored the cerebral turnover rates of serotonin and dopamine and decreased serum corticosterone levels. WGE and gastrodin inhibited the activity and protein expression of MAO-A, and increased TH levels in PC12 cells.


CONCLUSIONS
The antidepressant-like effects of WGE and gastrodin might be mediated by the regulation of monoamine neurotransmitters, and therefore were beneficial in depression treatment as a complementary approach.
Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
Yu-En
YE
Lin
Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
Shih-Hang
SH
Lin
Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
Wei-Cheng
WC
Chen
Department of Food Science, Rutgers University, New Brunswick, NJ 08901-8520, USA.
Chi-Tang
CT
Ho
Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
Yi-Syuan
YS
Lai
Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
Suraphan
S
Panyod
Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan. Electronic address: lysheen@ntu.edu.tw.
Lee-Yan
LY
Sheen
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001592:Benzyl Alcohols / Q000494:pharmacology / Q000627:therapeutic use*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D003345:Corticosterone / Q000097:blood; D003863:Depression / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D031668:Gastrodia; D005960:Glucosides / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D016716:PC12 Cells; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D027343:Rhizome; D012701:Serotonin / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D013315:Stress, Psychological / Q000097:blood / Q000188:drug therapy / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D014867:Water / Q000737:chemistry
D000928:Antidepressive Agents; D001592:Benzyl Alcohols; D005960:Glucosides; D008996:Monoamine Oxidase Inhibitors; D010936:Plant Extracts; D012997:Solvents; D014867:Water; D012701:Serotonin; C045345:gastrodin; D014446:Tyrosine 3-Monooxygenase; D008995:Monoamine Oxidase; D004298:Dopamine; D003345:Corticosterone
Depression; Gastrodia elata Blume; Gastrodin; Monoamines; Unpredictable chronic mild stress