title: Antidepressant-like activity of Chaihu-Shugan-San aqueous extract in rats and its possible mechanism.
abstract: BACKGROUND
  Chaihu-Shugan-San (CHSGS), a traditional Chinese medicinal formula, is commonly used for the treatment of depression in China. However, the molecular mechanism underlying its antidepressant action is unknown.
  
  
  OBJECTIVE
  The objective of this study is to evaluate the antidepressant-like effects of CHSGS and further explore the possible molecular mechanism implicated in its actions.
  
  
  METHODS
  THE RATS WERE RANDOMLY DIVIDED INTO FOUR GROUPS: The normal control group, the model control group, the CHSGS group and the fluoxetine control group. The antidepressant-like effects of CHSGS aqueous extract were assessed in rats exposed to chronic mild stress (CMS) using the open-field test and sucrose water consumption test, its underlying mechanism of anti-depression was explored by determining the effect of CHSGS on the extracellular signal-regulated kinase (ERK) and phospho-ERK (P-ERK) in the hippocampus using western blot. The aqueous extract of CHSGS at a dose of standard (5.9 g/kg·d) was administered intragastrically for 14 days during the CMS model while the fluoxetine control group was given at the same time using fluoxetine hydrochloride (1.8 mg/kg·d).
  
  
  RESULTS
  The stressed rats demonstrated decreased locomotor activity in open field test and reduction in sucrose consumption and decreased levels of P-ERK1/2 and the ratio of P-ERK1/2 to total ERK1/2 in the hippocampus. CHSGS alleviated the depressive-like behaviors and increased levels of P-ERK1/2 and the ratio of P-ERK1/2 to total ERK1/2 in stressed rats as well as fluoxetine.
  
  
  CONCLUSIONS
  In summary, these results suggest that CHSGS aqueous extract possesses an antidepressant-like activity in CMS induced depression model rats, which might be mediated, at least in part, by reversing the stress-induced disruption of ERK activity.
authors.affiliation: Department of Integrative Medicine, Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China ; Department of Integrative Medicine, Key Unit of State Administration of Traditional Chinese Medicine of the People's Republic of China, Changsha, Hunan, China.
authors.forename: Sue
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Integrative Medicine, Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China ; Department of Integrative Medicine, Key Unit of State Administration of Traditional Chinese Medicine of the People's Republic of China, Changsha, Hunan, China.
authors.forename: Suiyu
authors.initials: S
authors.lastname: Hu
authors.affiliation: Department of Integrative Medicine, Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China ; Department of Integrative Medicine, Key Unit of State Administration of Traditional Chinese Medicine of the People's Republic of China, Changsha, Hunan, China.
authors.forename: Chunhu
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Nuclear Medicine, Xiangya 3rd Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Qiu
authors.affiliation: Department of Integrative Medicine, Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China ; Department of Integrative Medicine, Key Unit of State Administration of Traditional Chinese Medicine of the People's Republic of China, Changsha, Hunan, China.
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Li
keywords: Antidepressant-like activity; Chaihu-Shugan-San; extracellular signal-regulated kinase; hippocampus