HPLC Separation of Vitamin E and Its Oxidation Products and Effects of Oxidized Tocotrienols on the Viability of MCF-7 Breast Cancer Cells in Vitro

J Agric Food Chem. 2015 Oct 14;63(40):8930-9. doi: 10.1021/acs.jafc.5b04388. Epub 2015 Oct 2.


Tocotrienols, a vitamin E subgroup, exert potent anticancer effects, but easily degrade due to oxidation. Eight vitamin E reference compounds, α-, β-, γ-, or δ-tocopherols or -tocotrienols, were thermally oxidized in n-hexane. The corresponding predominantly dimeric oxidation products were separated from the parent compounds by diol-modified normal-phase HPLC-UV and characterized by mass spectroscopy. The composition of test compounds, that is, α-tocotrienol, γ-tocotrienol, or palm tocotrienol-rich fraction (TRF), before and after thermal oxidation was determined by HPLC-DAD, and MCF-7 cells were treated with both nonoxidized and oxidized test compounds for 72 h. Whereas all nonoxidized test compounds (0-100 μM) led to dose-dependent decreases in cell viability, equimolar oxidized α-tocotrienol had a weaker effect, and oxidized TRF had no such effect. However, the IC50 value of oxidized γ-tocotrienol was lower (85 μM) than that of nonoxidized γ-tocotrienol (134 μM), thereby suggesting that γ-tocotrienol oxidation products are able to reduce tumor cell viability in vitro.

Keywords: HPLC-DAD; alamarBlue assay; dimeric oxidation products; human MCF-7 breast cancer cells; tocopherols; tocotrienols; viability; vitamin E.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / physiopathology
  • Cell Division / drug effects
  • Cell Survival / drug effects*
  • Chromatography, High Pressure Liquid
  • Female
  • Humans
  • MCF-7 Cells
  • Oxidation-Reduction
  • Tocotrienols / chemistry*
  • Tocotrienols / pharmacology
  • Vitamin E / chemistry*
  • Vitamin E / isolation & purification
  • Vitamin E / pharmacology*


  • Tocotrienols
  • Vitamin E