title: Supplementation with tocotrienol-rich fraction alters the plasma levels of Apolipoprotein A-I precursor, Apolipoprotein E precursor, and C-reactive protein precursor from young and old individuals.
abstract: OBJECTIVE
  Tocotrienol possess beneficial effects not exhibited by tocopherol. In vitro studies using animal models have suggested that these effects are caused via modulation of gene and protein expression. However, human supplementation studies using tocotrienol-rich isomers are limited. This study aims to identify plasma proteins that changed in expression following tocotrienol-rich fraction (TRF) supplementation within two different age groups.
  
  
  METHODS
  Subjects were divided into two age groups-32 ± 2 (young) and 52 ± 2 (old) years old. Four subjects from each group were assigned with TRF (78% tocotrienol and 22% tocopherol, 150 mg/day) or placebo capsules for 6 months. Fasting plasma were obtained at 0, 3, and 6 months. Plasma tocopherol and tocotrienol levels were determined. Plasma proteome was resolved by 2DE, and differentially expressed proteins identified by MS. The expressions of three proteins were validated by Western blotting.
  
  
  RESULTS
  Six months of TRF supplementation significantly increased plasma levels of tocopherols and tocotrienols. Proteins identified as being differentially expressed were related to cholesterol homeostasis, acute-phase response, protease inhibitor, and immune response. The expressions of Apolipoprotein A-I precursor, Apolipoprotein E precursor, and C-reactive protein precursor were validated. The old groups showed more proteins changing in expression.
  
  
  CONCLUSIONS
  TRF appears to not only affect plasma levels of tocopherols and tocotrienols, but also the levels of plasma proteins. The identity of these proteins may provide insights into how TRF exerts its beneficial effects. They may also be potentially developed into biomarkers for the study of the effects and effectiveness of TRF supplementation.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur City Campus, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia.
authors.forename: Eng Chee
authors.initials: EC
authors.lastname: Heng
authors.forename: Saiful Anuar
authors.initials: SA
authors.lastname: Karsani
authors.forename: Mariati
authors.initials: M
authors.lastname: Abdul Rahman
authors.forename: Noor Aini
authors.initials: NA
authors.lastname: Abdul Hamid
authors.forename: Zalina
authors.initials: Z
authors.lastname: Hamid
authors.forename: Wan Zurinah
authors.initials: WZ
authors.lastname: Wan Ngah
mesh_terms: D000210:Acute-Phase Reaction; D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D016632:Apolipoprotein A-I / Q000097:blood*; D001057:Apolipoproteins E / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D019587:Dietary Supplements; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006706:Homeostasis; D006801:Humans; D008875:Middle Aged; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D024505:Tocopherols / Q000097:blood; D024508:Tocotrienols / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D016632:Apolipoprotein A-I; D001057:Apolipoproteins E; D024508:Tocotrienols; D002097:C-Reactive Protein; D002784:Cholesterol; D024505:Tocopherols