Steep rise of docosahexaenoic acid in phosphatidylethanolamines of heart and liver of rats fed native olive oil or rapeseed oil

Abstract

It is not known so far whether the beneficial effects of dietary olive oil are solely due to high levels of oleic acid. Male Wistar rats were fed isocaloric diets containing 120 g/kg diet of three oleic acid-rich plant oils, i.e. high-oleic sunflower oil (HOS), olive oil (OLI), and Canola-type rapeseed oil (RAP), for 10 wk and the pattern of long-chain polyunsaturated fatty acids in total lipids, phosphatidylethanolamines and phosphatidylcholines in heart and liver lipids was studied. In the total lipids of heart and liver the proportion of docosahexaenoic (DHA) acid was significantly higher (2 to 3 fold) after feeding OLI and RAP as compared to HOS. The proportion of arachidonic acid was significantly higher (about 1.5 fold) in the total lipids of heart after feeding OLI and HOS as compared to RAP, but its level in the total liver lipids was not affected by the dietary oils. In rats fed OLI and RAP the proportions of individual long-chain polyunsaturated fatty acids were changed more extensively in the phosphatidylethanolamines of heart and liver than in the corresponding phosphatidylcholines. Especially, after feeding OLI and RAP a steep increase (3 to 4 fold) was found in the proportions of DHA in the phosphatidylethanolamines of heart and liver, whereas the percentage of arachidonic acid remained almost unchanged in the phosphatidylethanolamines of these organs irrespective of the dietary oil. The data indicate that both OLI and RAP may have beneficial effects on the prevention of atherosclerotic alterations by increasing the proportions of DHA in the membrane lipids, in particular phosphatidylethanolamines, of heart.