PREVENTION OF EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS IN LEWIS RATSBY A NOVEL FUNGAL SOURCE OF GAMMA-LINOLENIC ACID

The effects of oral administration of linoleic- and gamma-linolenic-ac id-rich oils on the clinical and histopathological manifestations of e xperimental autoimmune encephalomyelitis (EAE) were investigated in Le wis rats 7 d post-inoculation. gamma-linolenic-acid-rich fungal (Mucor javanicus) oil at 500 mg/kg body weight abrogated clinical and histol ogical signs of EAE although at doses of 200 and 1000 mg/kg body weigh t it was only effective in delaying the onset of clinical disease. Lin oleic-acid-rich safflower-seed (Carthamus tinctorius) oil at 500, 750 and 1000 mg/kg body weight decreased the severity of clinical EAE dise ase in a dose-dependent manner. The effects in healthy animals of oral ly administered gamma-linolenic-acid-rich fungal oil (500 mg/kg body w eight) and linoleic-acid-rich safflower-seed oil (1000 mg/kg body weig ht) on splenic lymphocyte proliferative responses to the T-cell mitoge n concanavalin-A (Con A), membrane fatty acid composition and lymphocy te sub-sets were also studied. Both treatments enhanced the T-cell pro liferative response to Con A. There was no significant effect on the p roportion of splenic CD8(+) or CD4(+) lymphocytes. Compositional studi es on splenic phosphoglyceride fatty acids of oil-treated animals sugg est the above responses were associated with increases in spleen dihom o-gamma-linolenic and arachidonic acids.