Protective effect of vitamin E on chromium (VI)-induced cytotoxicity and lipid peroxidation in primary cultures of rat hepatocytes.

Pretreatment of primary cultures of rat hepatocytes with alpha-tocopherol succinate (vitamin E) for 20 h prior to exposure to K2Cr2O7 resulted in a marked decrease of chromium (VI)-induced cytotoxicity, as evaluated by the leakage of lactate dehydrogenase, without affecting cellular uptake and the subcellular distribution of chromium. The levels of chromium (VI)-induced lipid peroxidation, as monitored by malondialdehyde formation, were also inhibited by pretreatment with the vitamin. Pretreatment with vitamin E normalized the levels of nonenzymatic antioxidants such as glutathione and vitamin C suppressed by dichromate, and caused a distinct accumulation of vitamin E in hepatocytes. However, vitamin E pretreatment did not affect the activities of enzymatic antioxidants including glutathione reductase, superoxide dismutase, and catalase suppressed by dichromate. These results indicate that the protective effect of vitamin E against chromium (VI)-induced cytotoxicity as well as lipid peroxidation, may be associated more with the level of nonenzymatic antioxidants than the activity of enzymatic antioxidants.