Neurotoxicity of pyridoxine analogs is related to coenzyme structure

Neurochem Pathol. Fall 1985;3(3):159-67. doi: 10.1007/BF02834268.


In very high doses, pyridoxine is neurotoxic in humans and other animals. Using morphometry and a model system of dorsal root ganglion neurons in culture, we found that several analogs of pyridoxine were neurotoxic in vitro. Those that may be converted into active coenzymes--pyridoxal, pyridoxine, and pyridoxamine--were almost equal in toxicity. Pyridoxic acid, which is not active, was nontoxic. Pyridoxamine 5-phosphate, which cannot enter cells, also was nontoxic. Several hypotheses that link coenzyme function to toxic effect are described.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Biotransformation
  • Cells, Cultured
  • Coenzymes / metabolism
  • Ganglia, Spinal / cytology
  • Ganglia, Spinal / drug effects*
  • Ganglia, Spinal / metabolism
  • Neurons / cytology
  • Neurons / drug effects
  • Neurons / metabolism
  • Pyridoxine / analogs & derivatives*
  • Pyridoxine / metabolism
  • Pyridoxine / toxicity*
  • Rats


  • Coenzymes
  • Pyridoxine