Comparison of the effect of lipoxygenase metabolites of arachidonic acid and eicosapentaenoic acid on human natural killer cell cytotoxicity.

We compared in vitro effect of lipoxygenase (LO) products derived from arachidonic acid (AA) and eicosapentaenoic acid (EPA) on cytotoxic activity of human natural killer (NK) cell against human erythroleukemia cell line K-562. Leukotriene B4 (LTB4) derived from AA was found to significantly augment NK cell activity compared to the control level (in the absence of LTB). LTB5 showed a weak, but not significant, enhancing effect on NK cell activity. LTB4 was significantly more potent than LTB5 in the enhancement of NK cell activity. On the other hand, both 5- and 15-hydroperoxy fatty acids derived from AA and EPA significantly enhanced NK cell activity compared to the control level with similar potencies.