title: [Baicalin increases the antioxidant capacity via promoting the nuclear translocation of NF-E2-related factor 2 (Nrf2) in N2a/APPswe cells].
abstract: OBJECTIVE
  To investigate the protective effect and related mechanism of baicalin in murine neuroblastoma N2a cells stably expressing human Swedish mutant amyloid precursor protein (APP) (N2a/APPswe cells), a cellular model of Alzheimer' s disease (AD).
  
  
  METHODS
  MTT assay was performed to observe the effect of baicalin (0.1, 0.5, 1, 5, 10, 20) μmol/L on the viability of N2a/APPswe cells. After N2a/APPswe cells were incubated with (1, 5, 10) μmol/L baicalin for 48 hours, xanthine oxidase assay was used to test superoxide dismutase (SOD) activity and thiobarbituric acid method to detect malondialdehyde (MDA) content in each group. Real-time quantitative PCR was applied to determine nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA, and Western blotting to examine protein levels of total Nrf2, nuclear Nrf2 and nuclear factor κB (NF-κB) in N2a/APPswe cells exposed to different doses of baicalin. Immunofluorescence staining was also used to observe the distribution of Nrf2.
  
  
  RESULTS
  We found that baicalin pretreatment increased cell viability. Compared with the control group (N2a/wt cells), SOD activity in N2a/APPswe cells significantly decreased, and MDA content significantly increased; but SOD activity was improved and MDA production was inhibited after pretreatment with baicalin, especially with 10 μmol/L bacalin. Both mRNA and total protein expression of Nrf2 were not significantly changed in baicalin treatment group compared with N2a/APPswe group, but the nuclear protein of Nrf2 distinctly increased after treatment with baicalin. In addition, baicalin decreased the level of nuclear NF-κB protein. Furthermore, immunofluorescence staining revealed that baicalin promoted the translocation of Nrf2 to the nucleus.
  
  
  CONCLUSIONS
  Baicalin has the protection against oxidative stress via activation of Nrf2 in N2a/APPswe cells.
authors.affiliation: Department of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Cao
authors.affiliation: Department of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Yushuang
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Neurology, First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China. *Corresponding author, E-mail: gangyuw2013@126.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002460:Cell Line; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D008315:Malondialdehyde / Q000378:metabolism; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism
chemical_list: D016564:Amyloid beta-Protein Precursor; D000975:Antioxidants; D005419:Flavonoids; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; C038044:baicalin; D008315:Malondialdehyde; D013482:Superoxide Dismutase; D005978:Glutathione