Effect of potassium sorbate on cellular GSH level and lipid peroxidation in cultured rat hepatocytes

Change in cellular reduced glutathione (GSH) level was examined after the addition of 1-10 mM potassium sorbate (SA-K) to cultured rat hepatocytes. The cellular GSH content was decreased to the lowest level at 6 h after the addition of SA-K, and then gradually returned to the normal level except for hepatocytes exposed to 10 mM SA-K. Although the decrease in GSH level was not associated with lactate dehydrogenase (LDH) leakage in hepatocytes exposed to SA-K up to the concentration of 5 mM, cell injury was caused in cells exposed to 10 mM SA-K. When eicosapentaenoic acid was added in conjunction with various concentrations of SA-K to hepatocytes, peroxidation of the fatty acid was accelerated in parallel with the decrease in cellular GSH level. The enhanced lipid peroxidation in the hepatocytes co-exposed to SA-K and eicosapentaenoic acid (EPA) induced the development of cell injury. These results suggest that hepatocytes exposed to SA-K become susceptible to oxidative stress such as lipid peroxidation.