Valproic acid treatment results in increased accumulation of prion proteins.

PrP(Sc), the only identified component of the prion, is an aberrant isoform of PrP(C), a glycoprotein of unknown function. In this study, it was shown that valproic acid, a widely used antiepileptic drug, can cause an increase of several orders of magnitude in the accumulation of PrP(C) in normal neuroblastoma cells (N2a), and of both PrP isoforms in scrapie infected neuroblastoma cells (ScN2a). Although preliminary results indicate that valproic acid administration to hamsters inoculated with prions had no significant effect on disease incubation time, it is suggested that administration of valproic acid to humans at risk of developing Creutzfeldt-Jakob disease should be evaluated with caution.