Introduction. Docosahexaenoic acid (DHA) has been shown to be immunosuppres
sive in the fetus, and fish oil diets are thought to be beneficial in autoi
mmune disease and transplantation. This effect may be mediated through nitr
ic oxide (NO), Here, we investigate the effect of DHA on murine macrophages
,
Methods. Peritoneal macrophages were subjected to stimulation with various
concentrations of interferon gamma-(IFN-gamma) and tumor necrosis factor al
pha (TNF-alpha). NO production was assessed by measuring nitrite (Greiss re
action),
Results. At all doses of IFN-gamma and TNF-alpha, DHA was found to be inhib
itory to NO production,
Conclusions. DHA inhibits macrophage-stimulated NO production in response t
o IFN-gamma and TNF-alpha. As NO is thought to be important in several dise
ase processes, DHA may be a useful agent in the treatment of conditions suc
h as autoimmune disease. (C) 1999 Academic Press.