Effects of Chronic Administration of Green Tea Ethanol Extract on Sleep Architecture in Mice: A Comparative Study with a Representative Stimulant Caffeine

Nutrients. 2023 Feb 20;15(4):1042. doi: 10.3390/nu15041042.


Wakefulness is defined as a state in which individuals can react to a change in situations. The number of people staying awake and compensating for lack of sleep has increased in recent years. Caffeine, a representative stimulant, is the most extensively consumed compound globally and is mainly consumed through coffee. Although green tea (Camellia sinensis L.) contains high caffeine content like coffee, its arousal-inducing effects have not yet been studied. In the present study, we aimed to identify the arousal-inducing effect of GT during a chronic administration period (three weeks) using analysis of sleep architecture. Treatment with GT (1500 mg/kg) significantly elevated the sleep latency and wakefulness throughout the treatment period, and chronic administration of GT consistently maintained an increase in wakefulness for up to 3 h. During the treatment period, the arousal-inducing effect of GT (1500 mg/kg) occurred without any change in the tolerance phenomenon or withdrawal symptoms, similar to that observed with caffeine (25 mg/kg). GT (1500 mg/kg) containing 95.6 mg/kg of caffeine did not produce a better arousal-inducing effect than caffeine at 25 mg/kg. These results indicate that the arousal-inducing effect of GT persisted for three weeks without adverse effects and that GT can control the arousal-inducing effects of caffeine due to the hypnotic effects of its other constituents.

Keywords: Camellia sinensis L.; arousal-inducing effect; caffeine; green tea ethanol extract; polysomnographic recording.

MeSH terms

  • Animals
  • Caffeine* / pharmacology
  • Camellia sinensis*
  • Central Nervous System Agents
  • Coffee
  • Ethanol / pharmacology
  • Mice
  • Plant Extracts / pharmacology
  • Sleep
  • Tea


  • Caffeine
  • Coffee
  • Ethanol
  • Tea
  • Central Nervous System Agents
  • Plant Extracts