Effects of Scutellaria baicalensis on chronic cerebral hypoperfusion-induced memory impairments and chronic lipopolysaccharide infusion-induced memory impairments

J Ethnopharmacol. 2011 Sep 1;137(1):681-9. doi: 10.1016/j.jep.2011.06.025. Epub 2011 Jun 21.


Ethnopharmacological relevance: Extracts of the roots of Scutellaria baicalensis Georgi (Labiatae) have been widely used to relieve fever related to bacterial infection and inflammatory diseases in traditional Korean medicine and have been reported to be effective in brain diseases. These experiments were conducted to examine the effects of oral administration of Scutellaria baicalensis extracts on the rescue of memory impairments induced by chronic cerebral hypoperfusion or chronic lipopolysaccharide (LPS) infusion. In addition, the underlying mechanisms of these effects were investigated.

Materials and methods: In the first experiment, chronic cerebral hypoperfusion was induced in male Wister rats by bilateral common carotid artery occlusion (BCCAo). Daily administration of Scutellaria baicalensis extracts was started on 20 day after BCCAo and given for 40 days. A Morris water maze was then used to evaluate the status of the hippocampal-dependent spatial learning and hippocampal mitogen-activated protein kinase (MAPK) signaling was examined in control rats, rats with chronic cerebral hypoperfusion, and rats with chronic cerebral hypoperfusion that was administered Scutellaria baicalensis. In the second experiment, hippocampal microglial activation was induced by chronic infusions of LPS into the fourth ventricle of Fisher-344 rat brains. Daily administration of Scutellaria baicalensis extracts was started on 7 day after the surgery of LPS infusion and given for 32 days. Spatial memory and hippocampal microglial activation was then examined in control rats with an artificial cerebrospinal fluid infusion, rats with chronic LPS infusion, and rats with chronic LPS infusion that were administered Scutellaria baicalensis.

Results: Rats that received chronic cerebral hypoperfusion or chronic LPS infusion showed spatial memory impairments relative to their control rats; however, these symptoms were reduced by daily administration of Scutellaria baicalensis. Administration of Scutellaria baicalensis mitigated alterations of hippocampal MAPK signaling by chronic cerebral infusion and microglial activation by chronic LPS infusion.

Conclusions: These results indicate that Scutellaria baicalensis may possess therapeutic potential for the prevention of Alzheimer's disease and vascular dementia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Brain Ischemia / complications*
  • Brain Ischemia / physiopathology
  • Brain Ischemia / psychology
  • Carotid Artery, Common / surgery
  • Cerebrovascular Circulation*
  • Chronic Disease
  • Hippocampus / drug effects*
  • Hippocampus / metabolism
  • Hippocampus / physiopathology
  • Ligation
  • Lipopolysaccharides
  • MAP Kinase Signaling System / drug effects
  • Male
  • Maze Learning / drug effects
  • Memory / drug effects*
  • Memory Disorders / drug therapy*
  • Memory Disorders / etiology
  • Memory Disorders / metabolism
  • Memory Disorders / physiopathology
  • Memory Disorders / psychology
  • Microglia / drug effects
  • Microglia / metabolism
  • Nootropic Agents / administration & dosage
  • Nootropic Agents / pharmacology*
  • Plant Extracts / administration & dosage
  • Plant Extracts / pharmacology*
  • Plant Roots
  • Plants, Medicinal
  • Rats
  • Rats, Inbred F344
  • Rats, Wistar
  • Scutellaria baicalensis
  • Time Factors


  • Lipopolysaccharides
  • Nootropic Agents
  • Plant Extracts
  • Scutellaria baicalensis extract