PT  - JOURNAL ARTICLE
AU  - TAKASHI YAMAZAKI
AU  - ATSUSHI YAMAZAKI
AU  - HIROYUKI ONUKI
AU  - YASUSHI HIBINO
AU  - YOSHIKO YOKOTE
AU  - HIROSHI SAKAGAMI
AU  - HIROSHI NAKAJIMA
AU  - JUN SHIMADA
TI  - Effect of Saliva, Epigallocatechin Gallate and Hypoxia on Cu-induced Oxidation and Cytotoxicity
DP  - 2007 Jul 01
TA  - In Vivo
PG  - 603--607
VI  - 21
IP  - 4
4099  - http://iv.iiarjournals.org/content/21/4/603.short
4100  - http://iv.iiarjournals.org/content/21/4/603.full
SO  - In Vivo2007 Jul 01; 21
AB  - We have previously reported that contact with copper (Cu) induced immediate cell death via an oxidation-involved mechanism in human promyelocytic leukemic HL-60 cells, whereas contact with other metals (Au, Ag, Pd) produced no discernible effect. In the present study, we investigated the conditions under which Cu-induced oxidative stress can be reduced. Contact with a Cu plate in the absence of cells enhanced the rate of consumption of cystine to the greatest extent, followed by that of methionine and histidine. Under hypoxic conditions, the consumption of all these amino acids was significantly reduced. On the other hand, the addition of saliva slightly, but not significantly, reduced the amino acid oxidation. The addition of epigallocatechin gallate (EGCG) slightly, but significantly reduced the consumption of cystine and histidine. The inhibitory effect of EGCG on the methionine consumption was more prominent, especially at higher concentrations. The Cu-induced cell death was significantly inhibited when freshly-prepared human gingival fibroblasts were incubated under hypoxic conditions. The present study demonstrates for the first time that the Cu-induced oxidation and cell death were effectively alleviated under hypoxic conditions. Copyright © 2007 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved