Korean Red Ginseng attenuates anxiety-like behavior during ethanol withdrawal in rats.
BACKGROUND
Korean Red Ginseng (KRG) is known to have antianxiety properties. This study was conducted to investigate the anxiolytic effects of KRG extract (KRGE) during ethanol withdrawal (EW) and the involvement of the mesoamygdaloid dopamine (DA) system in it.


METHODS
Rats were treated with 3 g/kg/d of ethanol for 28 d, and subjected to 3 d of withdrawal. During EW, KRGE (20 mg/kg/d or 60 mg/kg/d, p.o.) was given to rats once/d for 3 d. Thirty min after the final dose of KRGE, anxiety-like behavior was evaluated in an elevated plus maze (EPM), and plasma corticosterone (CORT) levels were determined by a radioimmunoassay (RIA). In addition, concentrations of DA and 3,4-dihydroxyphenylacetic acid (DOPAC) in the central nucleus of the amygdala (CeA) were also measured by high performance liquid chromatography (HPLC).


RESULTS
The EPM test and RIA revealed KRGE inhibited anxiety-like behavior and the over secretion of plasma CORT during EW. Furthermore, the behavioral effect was blocked by a selective DA D2 receptor (D2R) antagonist (eticlopride) but not by a selective DA D1 receptor (D1R) antagonist (SCH23390). HPLC analyses showed KRGE reversed EW-induced decreases of DA and DOPAC in a dose-dependent way. Additionally, Western blotting and real-time polymerase chain reaction (PCR) assays showed that KRGE prevented the EW-induced reductions in tyrosine hydroxylase (TH) protein expression in the CeA and TH mRNA expression in the ventral tegmental area (VTA).


CONCLUSIONS
These results suggest that KRGE has anxiolytic effects during EW by improving the mesoamygdaloid DA system.
Department of Pharmacology, Mudanjiang Medical University, Mudanjiang, China ; Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
ZhengLin
Z
Zhao
Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
Young Woo
YW
Kim
Department of Pharmacology, Mudanjiang Medical University, Mudanjiang, China.
YiYan
Y
Wu
Department of Pharmacology, Mudanjiang Medical University, Mudanjiang, China.
Jie
J
Zhang
Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
Ju-Hee
JH
Lee
Department of Pharmacology, Mudanjiang Medical University, Mudanjiang, China.
XiaoHua
X
Li
Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
Il Je
IJ
Cho
Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
Sang Mi
SM
Park
Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
Dae Hwa
DH
Jung
Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
Chae Ha
CH
Yang
Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
Sang Chan
SC
Kim
Department of Pharmacology, Mudanjiang Medical University, Mudanjiang, China ; Medical Research Center, College of Oriental Medicine, Daegu Haany University, Daegu, Korea.
RongJie
R
Zhao
Panax ginseng; amygdala; anxiety; dopamine; ethanol withdrawal