The ameliorating effect of oroxylin A on scopolamine-induced memory impairment in mice

Neurobiol Learn Mem. 2007 May;87(4):536-46. doi: 10.1016/j.nlm.2006.11.005. Epub 2006 Dec 28.


Oroxylin A is a flavonoid and was originally isolated from the root of Scutellaria baicalensis Georgi., one of the most important medicinal herbs in traditional Chinese medicine. The aim of this study was to investigate the ameliorating effects of oroxylin A on memory impairment using the passive avoidance test, the Y-maze test, and the Morris water maze test in mice. Drug-induced amnesia was induced by administering scopolamine (1 mg/kg, i.p.) or diazepam (1 mg/kg, i.p.). Oroxylin A (5 mg/kg) significantly reversed cognitive impairments in mice by passive avoidance and the Y-maze testing (P<.05). Oroxylin A also improved escape latencies in training trials and increased swimming times and distances within the target zone of the Morris water maze (P<.05). Moreover, the ameliorating effects of oroxylin A were antagonized by both muscimol and diazepam (0.25 mg/kg, i.p., respectively), which are GABA(A) receptor agonists. Furthermore, oroxylin A (100 microM) was found to inhibit GABA-induced inward Cl(-) current in a single cortical neuron. These results suggest that oroxylin A may be useful for the treatment of cognitive impairments induced by cholinergic dysfunction via the GABAergic nervous system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amnesia / chemically induced
  • Amnesia / prevention & control
  • Analysis of Variance
  • Animals
  • Avoidance Learning / drug effects*
  • Avoidance Learning / physiology
  • Cognition Disorders / drug therapy
  • Cognition Disorders / physiopathology
  • Drugs, Chinese Herbal / pharmacology*
  • Female
  • Flavonoids / pharmacology*
  • Male
  • Maze Learning / drug effects*
  • Maze Learning / physiology
  • Memory / drug effects*
  • Memory / physiology
  • Mice
  • Mice, Inbred ICR
  • Muscarinic Antagonists
  • Rats
  • Rats, Sprague-Dawley
  • Reaction Time / drug effects
  • Reaction Time / physiology
  • Receptors, GABA-A / drug effects*
  • Receptors, GABA-A / physiology
  • Scopolamine
  • Statistics, Nonparametric


  • Drugs, Chinese Herbal
  • Flavonoids
  • Muscarinic Antagonists
  • Receptors, GABA-A
  • 5,7-dihydroxy-6-methoxy-2-phenylchromen-4-one
  • Scopolamine