Effect of selenium supplementation on the activities of glutathione metabolizing enzymes in human hepatoma Hep G2 cell line

Cell culture is an important tool for studying injury to cells exposed to o xidative stress. The human hepatoblastoma derived Hep G2 cells retain their morphology and most of their Function in culture and are therefore widely used as an in vitro model of human hepatocytes. Conventional cell culture m edia are deficient in selenium, which is essential for activation of glutat hione peroxidase (GPx), a key enzyme in the defense against oxidative stres s. Supplementation of the culture media with 1 mu M sodium selenite increas ed the activities of total GPx by threefold and the selenium-dependent GPx by fourfold as compared to cells cultured in control media. The non-seleniu m-dependent GPx activity was unchanged. The activities of the other glutath ione (GSH)-related enzymes were practically unchanged despite a tendency to ward elevation. The activities of oxidized glutathione (GSSG) reductase and catalase increased by 22.4 and 27.4%, respectively. These relatively small increases did not carry statistical significance. Supplementation of tissu e culture media with selenium may prove important, particularly for cell pr otection against oxidative stress. (C) 2000 Elsevier Science Ireland Ltd. A ll rights reserved.