TY - JOUR
T1 - Green tea polyphenol epigallocatechin-3-gallate differentially modulates oxidative stress in PC12 cell compartments
AU - Raza, Haider
AU - John, Annie
N1 - Funding Information:
Authors wish to acknowledge the supports from the Terry Fox Cancer Research Fund and a grant from FMHS Research Committee, UAE University (HR). Thanks are also due to Ms Salama-Al-Mansouri and Ms Lekha Kumar for their help in preparation of the manuscript.
PY - 2005/9/15
Y1 - 2005/9/15
N2 - Tea polyphenols have been reported to be potent antioxidants and beneficial in oxidative stress related diseases. Prooxidant effects of tea polyphenols have also been reported in cell culture systems. In the present study, we have studied oxidative stress in the subcellular compartments of PC12 cells after treatment with different concentrations of the green tea polyphenol, epigallocatechin-3-gallate (EGCG). We have demonstrated that EGCG has differentially affected the production of reactive oxygen species (ROS), glutathione (GSH) metabolism and cytochrome P450 2E1 activity in the different subcellular compartments in PC12 cells. Our results have shown that although the cell survival was not inhibited by EGCG, there was, however, an increased DNA breakdown and activation of apoptotic markers, caspase 3 and poly- (ADP-ribose) polymerase (PARP) at higher concentrations of EGCG treatment. Our results suggest that the differential effects of EGCG might be related to the alterations in oxidative stress, GSH pools and CYP2E1 activity in different cellular compartments. These results may have implications in determining the chemopreventive therapeutic use of tea polyphenols in vivo.
AB - Tea polyphenols have been reported to be potent antioxidants and beneficial in oxidative stress related diseases. Prooxidant effects of tea polyphenols have also been reported in cell culture systems. In the present study, we have studied oxidative stress in the subcellular compartments of PC12 cells after treatment with different concentrations of the green tea polyphenol, epigallocatechin-3-gallate (EGCG). We have demonstrated that EGCG has differentially affected the production of reactive oxygen species (ROS), glutathione (GSH) metabolism and cytochrome P450 2E1 activity in the different subcellular compartments in PC12 cells. Our results have shown that although the cell survival was not inhibited by EGCG, there was, however, an increased DNA breakdown and activation of apoptotic markers, caspase 3 and poly- (ADP-ribose) polymerase (PARP) at higher concentrations of EGCG treatment. Our results suggest that the differential effects of EGCG might be related to the alterations in oxidative stress, GSH pools and CYP2E1 activity in different cellular compartments. These results may have implications in determining the chemopreventive therapeutic use of tea polyphenols in vivo.
KW - Apoptosis
KW - GSH metabolism
KW - Oxidative stress
KW - PC12 cells
KW - Tea polyphenol -EGCG
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U2 - 10.1016/j.taap.2005.01.004
DO - 10.1016/j.taap.2005.01.004
M3 - Article
C2 - 16129114
AN - SCOPUS:23944513613
SN - 0041-008X
VL - 207
SP - 212
EP - 220
JO - Toxicology and Applied Pharmacology
JF - Toxicology and Applied Pharmacology
IS - 3
ER -