Vitamin K has the potential to protect neurons from methylmercury-induced cell death in vitro

J Neurosci Res. 2011 Jul;89(7):1052-8. doi: 10.1002/jnr.22630. Epub 2011 Apr 12.


Vitamin K (VK) has a protective effect on neural cells. Methylmercury is a neurotoxicant that directly induces neuronal death in vivo and in vitro. Therefore, in the present study, we hypothesized that VK inhibits the neurotoxicity of methylmercury. To prove our hypothesis in vitro, we investigated the protective effects of VKs (phylloquinone, vitamin K(1); menaquinone-4, vitamin K(2) ) on methylmercury-induced death in primary cultured neurons from the cerebella of rat pups. As expected, VKs inhibited the death of the primary cultured neurons. It has been reported that the mechanisms underlying methylmercury toxicity involve a decrement of intracellular glutathione (GSH). Actually, treatment with GSH and a GSH inducer, N-acetyl cysteine, inhibited methylmercury-induced neuronal death in the present study. Thus, we investigated whether VKs also have protective effects against GSH-depletion-induced cell death by employing two GSH reducers, L-buthionine sulfoximine (BSO) and diethyl maleate (DEM), in primary cultured neurons and human neuroblastoma IMR-32 cells. Treatment with VKs affected BSO- and DEM-induced cell death in both cultures. On the other hand, the intracellular GSH assay showed that VK(2), menaquinone-4, did not restore the reduced GSH amount induced by methylmercury or BSO treatments. These results indicate that VKs have the potential to protect neurons against the cytotoxicity of methylmercury and agents that deplete GSH, without increasing intracellular GSH levels. The protective effect of VKs may lead to the development of treatments for neural diseases involving GSH depletion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Cell Death / drug effects
  • Cell Death / physiology
  • Cell Line, Tumor
  • Disease Models, Animal
  • Humans
  • In Vitro Techniques
  • Mercury Poisoning, Nervous System / metabolism
  • Mercury Poisoning, Nervous System / pathology
  • Mercury Poisoning, Nervous System / prevention & control*
  • Methylmercury Compounds / antagonists & inhibitors*
  • Methylmercury Compounds / toxicity
  • Nerve Degeneration / chemically induced
  • Nerve Degeneration / drug therapy*
  • Nerve Degeneration / pathology
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Neuroprotective Agents / pharmacology*
  • Neuroprotective Agents / therapeutic use
  • Rats
  • Rats, Wistar
  • Vitamin K / analogs & derivatives
  • Vitamin K / pharmacology*
  • Vitamin K / therapeutic use


  • Methylmercury Compounds
  • Neuroprotective Agents
  • Vitamin K