A preclinical assessment of d.l-govadine as a potential antipsychotic and cognitive enhancer

Int J Neuropsychopharmacol. 2012 Nov;15(10):1441-55. doi: 10.1017/S146114571100157X. Epub 2011 Nov 10.

Abstract

Tetrahydroprotoberberines (THPBs) are compounds derived from traditional Chinese medicine and increasing preclinical evidence suggests efficacy in treatment of a wide range of symptoms observed in schizophrenia. A receptor-binding profile of the THPB, d.l-govadine (d.l-Gov), reveals high affinity for dopamine and noradrenaline receptors, efficacy as a D2 receptor antagonist, brain penetrance in the 10-300 ng/g range, and thus motivated an assessment of the antipsychotic and pro-cognitive properties of this compound in the rat. Increased dopamine efflux in the prefrontal cortex and nucleus accumbens, measured by microdialysis, is observed following subcutaneous injection of the drug. d.l-Gov inhibits both conditioned avoidance responding (CAR) and amphetamine-induced locomotion (AIL) at lower doses than clozapine (CAR ED50: d.l-Gov 0.72 vs. clozapine 7.70 mg/kg; AIL ED50: d.l-Gov 1.70 vs. clozapine 4.27 mg/kg). Catalepsy is not detectable at low biologically relevant doses, but is observed at higher doses. Consistent with previous reports, acute d-amphetamine disrupts latent inhibition (LI) while a novel finding of enhanced LI is observed in sensitized animals. Treatment with d.l-Gov prior to conditioned stimulus (CS) pre-exposure restores LI to levels observed in controls in both sensitized animals and those treated acutely with d-amphetamine. Finally, possible pro-cognitive properties of d.l-Gov are assessed with the spatial delayed win-shift task. Subcutaneous injection of 1.0 mg/kg d.l-Gov failed to affect errors at a 30-min delay, but decreased errors observed at a 12-h delay. Collectively, these data provide the first evidence that d.l-Gov may have antipsychotic properties in conjunction with pro-cognitive effects, lending further support to the hypothesis that THPBs are a class of compounds which merit serious consideration as novel treatments for schizophrenia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antipsychotic Agents / chemistry
  • Antipsychotic Agents / pharmacology*
  • Avoidance Learning / drug effects*
  • Avoidance Learning / physiology
  • Berberine Alkaloids / chemistry
  • Berberine Alkaloids / pharmacology*
  • Cognition / drug effects*
  • Cognition / physiology
  • Drug Evaluation, Preclinical / methods
  • Male
  • Motor Activity / drug effects*
  • Motor Activity / physiology
  • Nootropic Agents / chemistry
  • Nootropic Agents / pharmacology*
  • Rats
  • Rats, Long-Evans

Substances

  • Antipsychotic Agents
  • Berberine Alkaloids
  • Nootropic Agents
  • govadine