Influence of dietary n-6 and n-3 lipids upon the development of pulmonary granulomas induced by Schistosoma mansoni eggs

Pulmonary granuloma development was studied in mice injected with 2x103 Schistosoma mansoni eggs through the main tail vein. Mice were divided into three groups and fed with a laboratory manipulated diet differing among them only in the source of fatty acids. Control group (CT) was fed with a soya oil diet; n-6 deficient animals (low n-6 group) received a supplemented coconut fat diet; and the third group, high n-3, was fed with a cod liver oil diet. The expected anti-inflammatory actions associated with essential fatty acids deficiency was noticed in our system. When compared with CT, animals fed with the n-6 deficient diet presented significantly reduced pulmonary granulomas 32 days after egg injection. Mice fed with high n-3 diet had pulmonary granulomas reduced as soon as 16 days post egg injection. Mean granuloma measurements for CT at days 8, 16 and 32 were, in 103μ2, respectively 7.52 5.92, 32.70 18.09, 32.22 19.87; for n-6 deficient animals 17.65 18.85, 36.14 29.14, 24.45 14.06; and for high n-3 group were 11.60 12.67, 9.97 12.34, 25.54 16.66