Effects of glucose and α-tocopherol on low-density lipoprotein oxidation and glycation

Chun Jen Chang, Rong Hong Hsieh, Hui Fang Wang, Mei Yun Chin, Shih Yi Huang

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Glycation of blood proteins is considered to be a major contributor to hyperglycemic complications in diabetes mellitus patients. In this study, we demonstrate the efficacy of α-tocopherol in reducing low-density lipoprotein (LDL) oxidation and glycation in vitro. Native LDL isolated from healthy subjects was exposed to various concentrations of glucose and malondialdehyde (MDA) with or without α-tocopherol enrichment for 7 days in sealed vacuum ampoules. The degree of glycation, copper-induced lag time, content of thiobarbituric acid-reactive substances (TBARS), and α-tocopherol levels in LDL were then assessed. LDL lag time was significantly reduced with high levels of glucose and MDA. α-Tocopherol enrichment dramatically inhibited the oxidation of LDL in the lag-time assay. However, the length of incubation time was inversely related to the LDL lag time. Longer incubation time resulted in shorter LDL lag time, with or without α-tocopherol enrichment. The level of TBARS associated with LDL oxidation was highest in native, MDA-supplemented, and high-glucose samples. The α-tocopherol levels were inversely related to glucose levels and incubation times. In conclusion, high-glucose concentrations heightened the oxidative susceptibility of LDL. α-Tocopherol enrichment reduced this trend and prevented LDL from undergoing architectural modification.

Original languageEnglish
Pages (from-to)294-302
Number of pages9
JournalAnnals of the New York Academy of Sciences
Volume1042
DOIs
Publication statusPublished - 2005

    Fingerprint

Keywords

  • α-tocopherol
  • Glucose
  • Glycation
  • LDL
  • Oxidation

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • History and Philosophy of Science

Cite this