TY - JOUR
T1 - Antioxidant properties of (-)-epicatechin-3-gallate and its inhibition of Cr(VI)-induced DNA damage and Cr(IV)- or TPA-stimulated NF-κB activation
AU - Shi, Xianglin
AU - Ye, Jianping
AU - Leonard, Stephen S.
AU - Ding, Min
AU - Vallyathan, Val
AU - Castranova, Vincent
AU - Rojanasakul, Yon
AU - Dong, Zigang
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2000
Y1 - 2000
N2 - Electron spin resonance (ESR) spin trapping was utilized to investigate the scavenging effects on hydroxyl radicals (OH) and superoxide radicals (O2-) by (-)-epigallocatechin-3-gallate (EGCG), one of the major anticancer compounds in tea. The spin trap used was 5,5-dimethyl-pyrroline N-oxide (DMPO). The Fenton reaction (Fe2+ + H2O2 → Fe3+ + OH + OH-) was used as a source of OH radicals. EGCG efficiently scavenges OH radicals with reaction rate of 4.62 x 1011 M-1 sec-1, which is an order of magnitude higher than several well recognized antioxidants, such as ascorbate, glutathione and cysteine. It also scavenges O2-radicals as demonstrated by using xanthine and xanthine oxidase system as a source of O2- radicals. Through its antioxidant properties, EGCG exhibited a protective effect against DNA damage induced by Cr(VI). EGCG also inhibited activation of nuclear transcription factor NF-κB induced by Cr(IV) and 12-o- tetradecanoylphorbol-13-acetate (TPA). The present studies provide a mechanistic basis for the reported anticarcinogenic properties of EGCG and related tea products.
AB - Electron spin resonance (ESR) spin trapping was utilized to investigate the scavenging effects on hydroxyl radicals (OH) and superoxide radicals (O2-) by (-)-epigallocatechin-3-gallate (EGCG), one of the major anticancer compounds in tea. The spin trap used was 5,5-dimethyl-pyrroline N-oxide (DMPO). The Fenton reaction (Fe2+ + H2O2 → Fe3+ + OH + OH-) was used as a source of OH radicals. EGCG efficiently scavenges OH radicals with reaction rate of 4.62 x 1011 M-1 sec-1, which is an order of magnitude higher than several well recognized antioxidants, such as ascorbate, glutathione and cysteine. It also scavenges O2-radicals as demonstrated by using xanthine and xanthine oxidase system as a source of O2- radicals. Through its antioxidant properties, EGCG exhibited a protective effect against DNA damage induced by Cr(VI). EGCG also inhibited activation of nuclear transcription factor NF-κB induced by Cr(IV) and 12-o- tetradecanoylphorbol-13-acetate (TPA). The present studies provide a mechanistic basis for the reported anticarcinogenic properties of EGCG and related tea products.
KW - Antiooxidants
KW - Cancer
KW - Epigallocatechin- 3-gallate
KW - Oxygen derived free radicals
KW - Tea
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U2 - 10.1023/a:1007012403691
DO - 10.1023/a:1007012403691
M3 - Article
C2 - 10839202
AN - SCOPUS:0034100482
SN - 0300-8177
VL - 206
SP - 125
EP - 132
JO - Molecular and Cellular Biochemistry
JF - Molecular and Cellular Biochemistry
IS - 1-2
ER -
