(-)-Epigallocatechin gallate attenuates glutamate-induced cytotoxicity via intracellular Ca modulation in PC12 cells.
1. The effects of (-)-epigallocatechin gallate (EGCG), a green tea polyphenol, on glutamate-induced increases in intracellular Ca2+ concentrations ([Ca2+]i) and cytotoxicity in PC12 cells were investigated. 2. Changes in [Ca2+]i were measured using Fura-2/AM calcium indicator dye and cellular viabilities were determined by a viable cell count and a 3-(4,4-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. 3. Glutamate increased [Ca2+]i in PC12 cells in a dose-dependent manner. (-)-Epigallocatechin gallate attenuated this glutamate (30 mmol/L)-induced [Ca2+]i increase and EGCG (50 micromol/L) increased the viability of PC12 cells against glutamate-induced cytotoxicity. The EGCG effect was also found to be independent of its general anti-oxidant mechanism. In contrast, EGCG directly suppressed both N-methyl-D-aspartate (50 mmol/L)- and kainate (20 mmol/L)-mediated Ca2+ influx, but not metabotropic receptor-mediated Ca2+ release. 4. These results suggest that EGCG reduces the glutamate-induced [Ca2+]i increase by attenuating ionotropic Ca2+ influx and that this promotes the viability of PC12 cells.
Department of Psychiatry, Catholic University of Daegu School of Medicine, Daegu, South Korea.
Jong-Hun
JH
Lee
Dae-Kyu
DK
Song
Chul-Ho
CH
Jung
Dong-Hoon
DH
Shin
JongWook
J
Park
Taeg Kyu
TK
Kwon
Byeong-Churl
BC
Jang
Kyo-Cheol
KC
Mun
Sang-Pyo
SP
Kim
Seong-Il
SI
Suh
Jae Hoon
JH
Bae
D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D018698:Glutamic Acid / Q000633:toxicity*; D007424:Intracellular Fluid / Q000187:drug effects* / Q000378:metabolism*; D016716:PC12 Cells; D051381:Rats
D018691:Excitatory Amino Acid Antagonists; D018698:Glutamic Acid; D002392:Catechin; C045651:epigallocatechin gallate; D002118:Calcium