EGCG attenuates AMPA-induced intracellular calcium increase in hippocampal neurons.
We have investigated the protective effect of (-)-epigallocatechin gallate (EGCG) on alpha-amino-3-hydroxy-5-methyl-4-isoxazolo propionate (AMPA)-induced toxicity in cultured rat hippocampal neurons. Treatment of 24 h AMPA (10 microM) reduced the neuronal viability in both survival neuron counting and MTT reduction assay compared with control, with increase in cellular concentrations of hydrogen peroxide and malondialdehyde. These responses to AMPA were significantly blocked by co-treatments with EGCG (10 microM), which effect was very similar to the protective ability of a known antioxidant catalase (2000 U/ml). AMPA (50 microM) elicited the increase in intracellular calcium concentration ([Ca(2+)]i) on which EGCG significantly attenuated both peak amplitude and sustained nature of that [Ca(2+)]i increase in a dose-dependent manner. These data suggest that EGCG has a neuroprotective effect against AMPA through inhibition of AMPA-induced [Ca(2+)]i increase and consequent attenuation of reactive oxygen species production and lipid peroxidation as an antioxidant and a radical scavenger.
Bae
Jae Hoon
JH
Department of Physiology, Keimyung University School of Medicine, 194 Dongsan-Dong, Choong-Gu, Daegu, 700-712, South Korea.
Mun
Kyo Cheol
KC
Park
Won Kyun
WK
Lee
Seung-Ryong
SR
Suh
Seong-Il
SI
Baek
Won Ki
WK
Yim
Man-Bin
MB
Kwon
Taeg Kyu
TK
Song
Dae-Kyu
DK
D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology*; D002413:Cations, Divalent / Q000037:antagonists & inhibitors / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D013997:Time Factors; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000037:antagonists & inhibitors / Q000633:toxicity*
D002413:Cations, Divalent; D018696:Neuroprotective Agents; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D002392:Catechin; D006861:Hydrogen Peroxide; C045651:epigallocatechin gallate; D002118:Calcium