title: Cinnamon polyphenols attenuate the hydrogen peroxide-induced down regulation of S100β secretion by regulating sirtuin 1 in C6 rat glioma cells.
abstract: OBJECTIVE
  It is well established that the brain is particularly susceptible to oxidative damage due to its high consumption of oxygen. The objective of this study was to investigate the protective effects of a water soluble polyphenol-rich extract of cinnamon and the possible mechanisms, under conditions of oxidative stress-induced by hydrogen peroxide, in rat C6 glioma cells.
  
  
  METHODS
  After 24h of H2O2 incubation, the secretion and intracellular expression of S100β were determined by immunoprecitation/immunoblotting and immunofluorescence imaging.
  
  
  RESULTS
  Cinnamon polyphenols (CP) counteracted the oxidative effects of H2O2 on S100β secretion and expression. CP also enhanced the impaired protein levels of sirtuins 1, 2, and 3, which are deacetylases important in cell survival. H2O2 also induced the overexpression of the proinflammatory factors, TNF-α, phospho-NF-κB p65, as well as of Bcl-xl, Bax and Caspase-3, which are all the members of the Bcl-2 family. CP not only suppressed the expression of these proteins but also attenuated the phosphorylation induced by H2O2. CP also upregulated the decreased Bcl-2 protein levels in H2O2 treated C6 cells. The effects of CP on H2O2-induced downregulation of S100β secretion were blocked by SIRT1 siRNA demonstrating that SIRT1 plays a regulatory role in CP-mediated prevention by H2O2.
  
  
  CONCLUSIONS
  These data demonstrate that Cinnamon polyphenols may exert neuroprotective effects in glial cells by the regulation of Bcl-2 family members and enhancing SIRT1 expression during oxidative stress.
authors.affiliation: IN Ingredients Inc, Columbia, TN 38401, USA(1); United States Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, Beltsville, MD 20705, USA. Electronic address: Bolin.Qin@ars.usda.gov.
authors.forename: Bolin
authors.initials: B
authors.lastname: Qin
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, Beltsville, MD 20705, USA; Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Kiran S
authors.initials: KS
authors.lastname: Panickar
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, Beltsville, MD 20705, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Anderson
mesh_terms: D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002935:Cinnamomum zeylanicum / Q000737:chemistry*; D015536:Down-Regulation / Q000187:drug effects; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation / Q000187:drug effects; D005910:Glioma / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000633:toxicity; D047468:Immunoprecipitation; D018384:Oxidative Stress / Q000187:drug effects*; D059808:Polyphenols / Q000302:isolation & purification / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D064568:S100 Calcium Binding Protein beta Subunit / Q000235:genetics* / Q000378:metabolism; D056564:Sirtuin 1 / Q000378:metabolism*
chemical_list: D059808:Polyphenols; D019253:Proto-Oncogene Proteins c-bcl-2; D064568:S100 Calcium Binding Protein beta Subunit; C579158:S100b protein, rat; D006861:Hydrogen Peroxide; D056564:Sirtuin 1
keywords: Oxidative stress; Polyphenols; S100β; SIRT1