title: Neuroprotective and anti-oxidant effects of caffeic acid isolated from Erigeron annuus leaf.
abstract: BACKGROUND
  Since oxidative stress has been implicated in a neurodegenerative disease such as Alzheimer's disease (AD), natural antioxidants are promising candidates of chemopreventive agents. This study examines antioxidant and neuronal cell protective effects of various fractions of the methanolic extract of Erigeron annuus leaf and identifies active compounds of the extract.
  
  
  METHODS
  Antioxidant activities of the fractions from Erigeron annuus leaf were examined with [2,2-azino-bis(3-ethylbenz thiazoline-6-sulfonic acid diammonium salt)] (ABTS) and ferric reducing antioxidant power (FRAP) assays. Neuroprotective effect of caffeic acid under oxidative stress induced by H2O2 was investigated with [3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) and lactate dehydrogenase (LDH) assays.
  
  
  RESULTS
  This study demonstrated that butanol fraction had the highest antioxidant activity among all solvent fractions from methanolic extract E. annuus leaf. Butanol fraction had the highest total phenolic contents (396.49 mg of GAE/g). Caffeic acid, an isolated active compound from butanol fraction, showed dose-dependent in vitro antioxidant activity. Moreover, neuronal cell protection against oxidative stress induced cytotoxicity was also demonstrated.
  
  
  CONCLUSIONS
  Erigeron annuus leaf extracts containing caffeic acid as an active compound have antioxidative and neuroprotective effects on neuronal cells.
authors.affiliation: Department of Food Science and Technology, Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 660-701, Korea. hjher@gnu.ac.kr.
authors.forename: Chang-Ho
authors.initials: CH
authors.lastname: Jeong
authors.forename: Hee Rok
authors.initials: HR
authors.lastname: Jeong
authors.forename: Gwi Nam
authors.initials: GN
authors.lastname: Choi
authors.forename: Dae-Ok
authors.initials: DO
authors.lastname: Kim
authors.forename: Uk
authors.initials: U
authors.lastname: Lee
authors.forename: Ho Jin
authors.initials: HJ
authors.lastname: Heo