In vitro comparative study of cytolysis mediated by natural killer cells towards malignant cells preincubated with antioxidants.

We have previously reported that antioxidants such as beta-carotene, were able to enhance cytolytic activity of NK cells. The aim of the present study was to investigate whether preincubating YAC-1 tumor cells in culture with different antioxidants, affected their NK cell-mediated cytolysis. The antioxidants studied were enzymes (superoxide dismutase and catalase), hydroxyl radical scavengers (thiourea, mannitol, dimethyl sulfoxide) and a singlet oxygen quencher: beta-carotene.