(-)-Epigallocatethin-3-O-gallate counteracts caffeine-induced hyperactivity: evidence of dopaminergic blockade.
This experiment was designed to know whether (-)-epigallocatethin-3-O-gallate (EGCG) counteracts caffeine-induced hyperactivity, and its potential mechanisms in mice. EGCG inhibited methamphetamine-induced, cocaine-induced and caffeine-induced horizontal hyperlocomotion and rearing activity. EGCG also inhibited hyperlocomotion and rearing activity induced by apomorphine, a D1/D2-like agonist. Moreover, EGCG inhibited climbing behavior, a typical stereotyped behavior induced by stimulation of dopamine receptors through the activation of those receptors by apomorphine. From this experiment, we suggest that EGCG inhibits hyperactivity induced by psychostimulants including caffeine, in part by modulating dopaminergic transmission, and these inhibitory effects of EGCG counteract the stimulant actions of caffeine in green tea.
Park
Kwang-Soon
KS
College of Pharmacy, Chungbuk National University, Cheongju, Korea.
Eun
Jae Soon
JS
Kim
Hyoung-Chun
HC
Moon
Dong-Cheul
DC
Hong
Jin-Tae
JT
Oh
Ki-Wan
KW
D000818:Animals; D002110:Caffeine / Q000633:toxicity*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000633:toxicity*; D006948:Hyperkinesis / Q000139:chemically induced / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D017447:Receptors, Dopamine D1 / Q000187:drug effects / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000378:metabolism; D013239:Stereotyped Behavior / Q000187:drug effects; D013662:Tea / Q000737:chemistry
D000697:Central Nervous System Stimulants; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D013662:Tea; D002110:Caffeine; D002392:Catechin; C045651:epigallocatechin gallate