title: Protective effect of caffeic acid against beta-amyloid-induced neurotoxicity by the inhibition of calcium influx and tau phosphorylation.
abstract: OBJECTIVE
  The progressive accumulation of beta-amyloid peptide (Abeta), in the form of senile plaques, has been recognized as one of the major causes of Alzheimer's disease (AD) pathology. Increased production of Abeta and the aggregation of Abeta to oligomers have been reported to trigger neurotoxicity, oxidative damage and inflammation. Furthermore, Abeta-induced tau hyperphosphorylation and neurotoxicity are downstream of Abeta. Therefore, we studied the possible neuroprotective effects of caffeic acid against Abeta-induced toxicity.
  
  
  METHODS
  Treatment of PC12 cells with 10 microM Abeta (25-35) for 24 h significantly decreased the cell viability; this was accompanied by an increase in intracellular calcium levels and tau phosphorylation with GSK-3beta (glycogen synthase kinase-3beta) activation (phosphorylation).
  
  
  RESULTS
  However, pretreatment of the PC12 cells with 10 and 20 microg/ml of caffeic acid, for 1 h prior to Abeta, significantly reversed the Abeta-induced neurotoxicity by attenuating the elevation of intracellular calcium levels and tau phosphorylation.
  
  
  CONCLUSIONS
  Taken together, these results suggest that caffeic acid protected the PC12 cells against Abeta-induced toxicity. In addition, the neuroprotective mechanisms of caffeic acid against Abeta attenuated intracellular calcium influx and decreased tau phosphorylation by the reduction of GSK-3beta activation.
authors.affiliation: Environmental Toxico-Genomic and Proteomic Center, College of Medicine, Korea University, Anamdong 5, Sungbuk-Ku, Seoul 136-701, Republic of Korea.
authors.forename: Donggeun
authors.initials: D
authors.lastname: Sul
authors.forename: Hyo-Shin
authors.initials: HS
authors.lastname: Kim
authors.forename: Dongho
authors.initials: D
authors.lastname: Lee
authors.forename: Seong Soo
authors.initials: SS
authors.lastname: Joo
authors.forename: Kwang Woo
authors.initials: KW
authors.lastname: Hwang
authors.forename: So-Young
authors.initials: SY
authors.lastname: Park
mesh_terms: D016229:Amyloid beta-Peptides / Q000378:metabolism / Q000633:toxicity; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002109:Caffeic Acids / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D016716:PC12 Cells; D010446:Peptide Fragments / Q000378:metabolism / Q000633:toxicity; D010766:Phosphorylation; D051381:Rats; D016875:tau Proteins / Q000378:metabolism*
chemical_list: D016229:Amyloid beta-Peptides; D000975:Antioxidants; D002109:Caffeic Acids; D010446:Peptide Fragments; C074636:amyloid beta-protein (25-35); D016875:tau Proteins; D002118:Calcium; C040048:caffeic acid