Enhanced incorporation of docosahexaenoic acid in serum, heart, and brain of rats given microemulsions of fish oil

Long-chain n-3 fatty acids are essential for the development of cognitive functions and reducing the risk factor for cardiovascular diseases. The present study was undertaken to prepare fish oil (FO) microemulsion and explore the possibility of enhancing the enrichment of long-chain n-3 PUFA in the heart and brain lipids. The bioavailability of encapsulated FO was compared with that of native oil in rats by utilizing the intestinal sac method and by an in vivo study giving microemulsions of FO through intubation for a period of 30 days. Microemulsions were prepared using chitosan, gum acacia, whey protein, and lipoid. The bioavailability of eicosapentaenoic acid and docosahexaenoic acid (DHA) from FO encapsulated in chitosan, gum acacia, whey protein, and lipoid was increased by 7, 9, 23, and 68 %, respectively, as compared to oil given without encapsulation in the everted intestinal sacs model. The DHA levels in serum lipids when FO was given as lipoid emulsion to rats were found to be 56 μg/ml, while rats given FO without encapsulation had a DHA level of 22 μg/ml. In the heart and brain lipids, the DHA levels were increased by 77 and 41 %, respectively, in rats given FO encapsulated with lipoid compared to those given native oil. These studies indicated that DHA from FO was taken up in a more efficient manner when given in an encapsulated form with lipoid. Thus, phospholipid-based binding materials such as Lipoid provide a good delivery system for FO and significantly enhance DHA levels in the serum, liver, heart, and brain tissues.