Effect of Long-Term Feeding of Dietary Docosahexaenoic Acid and Egg-Phosphatidylcholine on the Fatty Acid Composition of Plasma, Brain Total Lipids and Phospholipids in Adult and Old Mice

Abstract

The effect of long-term feeding of dietary docosahexaenoic acid (DHA, 22:6n-3) and egg-phosphatidylcholine (egg-PC) on changes in the fatty acid composition of plasma, brain total lipids and phospholipids was studied in adult and old mice. Male Crj:CD-1 mice aged either 3 weeks or 14 months were fed a diet containing 2% DHA and 3% palm oil (DHA Group), 5% egg-PC (Egg-PC Group), 1% DHA, 2.5% egg-PC and 1.5% palm oil (DHA + egg-PC Group), 5% palm oil (Palm oil Control Group) or MF laboratory chow (MF Control Group) for 8 months. After the feeding trials, all mice were sacrificed and plasma samples and brain homogenates were analyzed for fatty acid composition. The changes in fatty acid composition followed a similar pattern in each diet group in both adult and old mice. In the plasma and brain homogenates of the mice fed the DHA diet, a significant increase in DHA levels was accompanied by a concomitant decrease in arachidonic acid (AA, 20:4n-6) (p < 0.05). Similar changes in fatty acid composition were also observed in brain PC and phosphatidylethanolamine in mice in this diet group. However, this pattern of change in brain fatty acids was not evident in mice which had been fed the egg-PC diet. This latter group had the highest level of AA of all diet groups in the plasma lipids of both adult and old mice but this difference was not evident in brain lipids. Old mice exhibited a lower DHA level in brain PC than adult mice (p < 0.05) in all diet groups.

Keywords:

• Brain
• Docosahexaenoic acid (DHA)
• Fatty acid composition
• Phosphatidylcholine (PC)
• Plasma