[Biological activity of fish oil].

Omega-3 fatty acids (n-3) found specially on fish oil are represented by the acid alfa-linolenic, eicosapeniaenoic and docosahexaenoic. After 72 hours of n-3 fatty acids intake there are changes on membrane composition and decrease of synthesis of prostaglandin (PG), leucotriens (LT) and thromboxanes (TX) of the 2 and 4 series production and substitution for prostaglandin, thromboxanes and leucotriens of 3 and 5 series respectively. These alterations can modulate the inflammatory response in some diseases. N-3 fatty acid have been used in cardiology on hypercholesterolemy and hypertension control and on immunologic diseases as psoriasis, rheumatoid arthritis and Crohn disease. Experimentally the n-3 fatty acid inhibit tumor growth and metastasis. The authors consider the biophysiological actions of n-3 fatty acids and discuss the results of its use on clinical results.