Suppression of human T-cell growth in vitro by cis-unsaturated fatty acids: relationship to free radicals and lipid peroxidation.

Cis-unsaturated fatty acids such as dihomogamma-linolenic acid (DGLA), arachidonic acid (AA) and eicosapentaenoic acid (EPA), which form precursors to 1, 2 and 3 series prostaglandins (PGs), have been shown to suppress human T-cell growth in vitro by a prostaglandin E (PGE)-independent mechanism. In an earlier study, we showed that these fatty acids can induce free radical generation in human neutrophils and tumor cells. Here we show that cis-unsaturated fatty acids augment free radical generation and lipid peroxidation in human T-cells. The growth suppressive action of cis-unsaturated fatty acids on human T-cells could be blocked by anti-oxidant, vitamin E and the superoxide anion quencher superoxide dismutase. These results suggest that c-UFAs-induced cell growth suppression is a free radical dependent process.