Alpha-tocotrienol provides the most potent neuroprotection among vitamin E analogs on cultured striatal neurons

Neuropharmacology. 2004 Nov;47(6):904-15. doi: 10.1016/j.neuropharm.2004.06.029.

Abstract

Oxidative stress and apoptosis play pivotal roles in the pathogenesis of neurodegenerative diseases. We investigated the effects of vitamin E analogs on oxidative stress and apoptosis using primary neuronal cultures of rat striatum. A tocotrienol-rich fraction of edible oil derived from palm oil (Tocomin 50%), which contains alpha-tocopherol, and alpha-, gamma- and delta-tocotrienols, significantly inhibited hydrogen peroxide (H2O2)-induced neuronal death. Each of the tocotrienols, purified from Tocomin 50% by high-performance liquid chromatography, significantly attenuated H2O2-induced neurotoxicity, whereas alpha-tocopherol did not. alpha-, gamma- and delta-Tocotrienols also provided significant protection against the cytotoxicity of a superoxide donor, paraquat, and nitric oxide donors, S-nitrosocysteine and 3-morpholinosydnonimine. Moreover, tocotrienols blocked oxidative stress-mediated cell death with apoptotic DNA fragmentation caused by an inhibitor of glutathione synthesis, L-buthionine-[S,R]-sulfoximine. In addition, alpha-tocotrienol, but not gamma- or delta-tocotrienol, prevented oxidative stress-independent apoptotic cell death, DNA cleavage and nuclear morphological changes induced by a non-specific protein kinase inhibitor, staurosporine. These findings suggest that alpha-tocotrienol can exert anti-apoptotic neuroprotective action independently of its antioxidant property. Among the vitamin E analogs examined, alpha-tocotrienol exhibited the most potent neuroprotective actions in rat striatal cultures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimetabolites / antagonists & inhibitors
  • Antimetabolites / toxicity
  • Antioxidants / pharmacology*
  • Apoptosis / drug effects
  • Bisbenzimidazole
  • Buthionine Sulfoximine / antagonists & inhibitors
  • Buthionine Sulfoximine / toxicity
  • Carcinogens / antagonists & inhibitors
  • Carcinogens / toxicity
  • Cell Survival / drug effects
  • Cells, Cultured
  • Chromatography, High Pressure Liquid
  • Fluorescent Dyes
  • Hydrogen Peroxide / antagonists & inhibitors
  • Hydrogen Peroxide / toxicity
  • Immunohistochemistry
  • In Situ Nick-End Labeling
  • L-Lactate Dehydrogenase / metabolism
  • Neostriatum / cytology*
  • Neostriatum / drug effects
  • Neurons / drug effects*
  • Neuroprotective Agents / pharmacology*
  • Oxidative Stress / drug effects
  • Rats
  • Rats, Wistar
  • Staurosporine / antagonists & inhibitors
  • Staurosporine / toxicity
  • Tetrazolium Salts
  • Thiazoles
  • Tocotrienols
  • Vitamin E / analogs & derivatives*
  • Vitamin E / pharmacology*

Substances

  • Antimetabolites
  • Antioxidants
  • Carcinogens
  • Fluorescent Dyes
  • Neuroprotective Agents
  • Tetrazolium Salts
  • Thiazoles
  • Tocotrienols
  • Vitamin E
  • Buthionine Sulfoximine
  • tocotrienol, alpha
  • Hydrogen Peroxide
  • L-Lactate Dehydrogenase
  • thiazolyl blue
  • Staurosporine
  • Bisbenzimidazole