Theanine prevents memory impairment induced by repeated cerebral ischemia in rats

Phytother Res. 2008 Jan;22(1):65-8. doi: 10.1002/ptr.2261.


The present study investigated the neuroprotective effect of gamma-glutamylethylamide (theanine), a component Japanese green tea (Camellia sinensis), on memory impairment induced by twice-repeated cerebral ischemia in rats. Theanine was injected i.p. immediately after the first occlusion. Theanine (0.3 and 1 mg/kg) significantly prevented the impairment of spatial memory in rats subjected to repeated cerebral ischemia, 7 days after the second reperfusion. Moreover, theanine (1 mg/kg) significantly inhibited the decrease in the number of surviving cells in the hippocampal CA1 field in the same rats. These results suggest that theanine prevents memory impairment induced by repeated cerebral ischemia, in part by protecting against neuronal cell death, and that it might be useful for preventing cerebrovascular disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Ischemia / complications*
  • Cell Death / drug effects
  • Dose-Response Relationship, Drug
  • Glutamates / administration & dosage
  • Glutamates / pharmacology*
  • Injections, Intraperitoneal
  • Male
  • Maze Learning / drug effects
  • Memory Disorders / etiology
  • Memory Disorders / prevention & control*
  • Neuroprotective Agents / administration & dosage
  • Neuroprotective Agents / pharmacology*
  • Rats
  • Rats, Wistar
  • Tea / chemistry


  • Glutamates
  • Neuroprotective Agents
  • Tea
  • theanine