A Study on the Protective Effects of Glutathione on Cytotoxicity of Mercury and Cadmium

Jeong, Jae Ho; Kim, Jun Youn; Koh, Dai Ha

Abstract

OBJECTIVES
To evaluate the protective effects of glutathione (GSH) on the cytotoxicity of mercurial compounds(CH3HgCl, HgCl2) or cadmium chloride(CdCl2) in EMT-6 cells.
METHODS
The compounds investigated were CH3HgCl, HgCl2, CdCl2, GSH, buthionine sulfoximine(BSO), L-2-oxothiazolidine-4-carboxylic acid(OTC). Cytotoxicity analysis consist of nitric oxide(NO) production, ATP production and cell viability.
RESULTS
Mercurial compounds and cadmium chloride significantly decreased cell viability and the synthesis of NO and cellular ATP in EMT-6 cells. GSH was not toxic at concentrations of 0 - 1.6 mM. In the presence of GSH, mercurial compounds and cadmium did not decrease the production of ATP and nitrite in EMT-6 cells. The protective effects of GSH against the cytotoxicity of mercurial compounds and cadmium depended on the concentration of added GSH to the culture medium for EMT-6 cells. We evaluated the effects of intracellular GSH level on mercury- or cadmium-induced cytotoxicity by the pretreatment experiments. Pretreatment of GSH was not changed NO2- and ATP production, and pretreatment of BSO was decreased in dose- and time-dependent manner. Pretreatment of OTC was increased NO2- and ATP production in dose- and time-dependent manner. Because intracellular GSH level was increased by OTC pretreatment, the protective effect on mercury- and cadmium-induced cytotoxicity was increased.
CONCLUSIONS
These results indicated that sulfhydryl compounds had the protective effects against mercury-induced cytotoxicity by the intracellular GSH levels.