title: Cajaninstilbene acid prevents corticosterone-induced apoptosis in PC12 cells by inhibiting the mitochondrial apoptotic pathway.
abstract: OBJECTIVE
  Cajaninstilbene acid (3-hydroxy-4-prenyl-5-methoxystilben-2 -carboxylic acid, CSA), a natural stilbene isolated from the leaves of Cajanus cajan, has attracted considerable attention for its wide range of pharmacological activities. This study investigated whether CSA protects against corticosterone (CORT)-induced injury in PC12 cells and examined the potential mechanisms underlying this protective effect.
  
  
  METHODS
  Cell viability and cytotoxicity were detected using a 3-(4,5-desethyithiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) assay kit, respectively. PC12 cell apoptosis was measured using Hoechst 33342 staining and a DNA fragmentation assay kit, and intracellular Ca(2+) concentrations were assessed by fluorescent labelling. Next, the mitochondrial permeability transition pores (mPTPs) and mitochondrial membrane potentials (∆Ψm) were detected using a colorimetric mPTP detection kit and a 5,5',6,6'-tetrachloro-1,1',3,3'- tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) kit, respectively. Finally, cytochrome c, caspase-3 and inhibitor of caspase-activated deoxyribonuclease (ICAD) expression levels were monitored by western blot analysis.
  
  
  RESULTS
  Treatment with 100 µmol/l CORT induced cytotoxicity in PC12 cells. However, CSA dose-dependently increased cell viability and decreased LDH release as well as CORT-induced apoptosis. Mechanistically, compared with the CORT-treated group, CSA strongly attenuated intracellular Ca(2+) overload and restored mitochondrial functions, including mPTPs and ∆Ψm. Furthermore, the down-regulation of cytochrome c and ICAD protein expression and the blockage of caspase-3 activity were observed upon CSA treatment.
  
  
  CONCLUSIONS
  In summary, our data are the first to show that the in vitro antidepressant-like effect of CSA may be attributed to the cytoprotection of neurons and that such neuroprotective mechanisms are correlated with intracellular Ca(2+) homeostasis and mitochondrial apoptotic pathways.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Science, Peking Union Medical College, Beijing, China.
authors.forename: Bao-Ping
authors.initials: BP
authors.lastname: Jiang
authors.forename: Ya-Min
authors.initials: YM
authors.lastname: Liu
authors.forename: Liang
authors.initials: L
authors.lastname: Le
authors.forename: Zong-Yang
authors.initials: ZY
authors.lastname: Li
authors.forename: Jian-Yong
authors.initials: JY
authors.lastname: Si
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Liu
authors.forename: Qi
authors.initials: Q
authors.lastname: Chang
authors.forename: Rui-Le
authors.initials: RL
authors.lastname: Pan
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D003345:Corticosterone / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D053938:DNA Fragmentation / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects*; D016716:PC12 Cells; D051381:Rats; D012459:Salicylates / Q000494:pharmacology*; D013267:Stilbenes / Q000494:pharmacology*
chemical_list: C549543:3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid; D012459:Salicylates; D013267:Stilbenes; D003345:Corticosterone