title: Cinnamic aldehyde treatment alleviates chronic unexpected stress-induced depressive-like behaviors via targeting cyclooxygenase-2 in mid-aged rats.
abstract: BACKGROUND
  COX-2 has been considered as a potent molecular target for prevention and therapy of depression. However, a recent study showed that COX-2 inhibitor does not improve depressive symptoms in persons aged 70 and over. Therefore, whether treatments targeting COX-2 have a clinical efficacy in depression, especially elderly individuals, remains unclear. Cinnamic aldehyde is a major constituent of Cinnamomum cassia, which has exhibited excellent anti-inflammatory activities as a COX-2 inhibitor. To investigate the potential antidepressant effect of cinnamic aldehyde in mid-aged rats.
  
  
  METHODS
  The depressive-like behaviors were measured after the rats exposed to chronic unexpected mild stress (CUMS). Cinnamic aldehyde was administrated by oral gavage to stressed rats (22.5, 45, 90 mg/kg, respectively) for 21 days. The mRNA, protein expression and activity of cyclooxygenase-2 (COX-2), as well as prostaglandin E2 (PGE2) levels were measured in the frontal cortex and hippocampus of stressed animals.
  
  
  RESULTS
  We found that CUMS procedure not only decreased the sucrose preference, but also elevated the COX-2 activity, mRNA and protein levels, and increased PGE2 concentration in rat brain regions. Treatment with high doses of cinnamic aldehyde (45, 90 mg/kg) reversed the behavioral abnormalities, and decreased the COX-2 protein and activity (but not COX-2 mRNA expression) and PGE2 concentration in frontal cortex and hippocampus of stressed rats.
  
  
  CONCLUSIONS
  Cinnamic aldehyde exerted antidepressant-like effects in stressed mid-aged rats, and its mechanism of action appears to decrease COX-2 protein and activity. The current findings suggest that targeting COX-2 system might be benefit to the depression, especially elderly individuals and cinnamic aldehyde might be a promising medicine to treat the subjects in the depression.
authors.affiliation: Pharmacy Department, Zhejiang Medical College, Hangzhou 310053, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yao
authors.affiliation: School of Pharmacy, Henan University of Traditional Chinese Medicine, Zhengzhou 450046, China.
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: Huang
authors.affiliation: School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China.
authors.forename: Yuan-Xiao
authors.initials: YX
authors.lastname: Yang
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 16# Lincui Road, Chaoyang District, Beijing 100101, China. Electronic address: guojy@psych.ac.cn.
authors.forename: Jian-You
authors.initials: JY
authors.lastname: Guo
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D000375:Aging; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D001522:Behavior, Animal / Q000187:drug effects; D002908:Chronic Disease; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D003863:Depression / Q000188:drug therapy* / Q000378:metabolism; D015232:Dinoprostone / Q000235:genetics / Q000378:metabolism; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008517:Phytotherapy; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000188:drug therapy* / Q000378:metabolism
chemical_list: D000928:Antidepressive Agents; D012333:RNA, Messenger; D000171:Acrolein; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; D015232:Dinoprostone; C012843:cinnamaldehyde
keywords: Aged; Cinnamic aldehyde; Cyclooxygenase-2; Depression; Prostaglandin E2