Curcumin and linseed oil co-delivered in phospholipid nanoemulsions enhances the levels of docosahexaenoic acid in serum and tissue lipids of rats

Docosahexaenoic acid (DHA) is an important long chain omega-3 polyunsaturated fatty acid (PUFA) primarily found in marine fishes. The diets of vegetarian population do not contain preformed DHA, but they can derive it from shorter chain α-linolenic acid (ALA) found in plant oils. However, the conversion efficiency of ALA to DHA is minimal in human adults. This may cause insufficiency of DHA in the vegetarian population. Curcumin, diferuloyl methane found in the spice turmeric, has the potential to increase the formation of DHA from ALA by activating the enzymes FADS2 and elongase 2. The present study was designed to prepare curcumin nanoemulsion using phospholipid core material (Lipoid™) and exploring the possibility of enhancing its bioavailability and its impact on DHA levels in rats. Curcumin was dissolved in coconut oil (CNO, MCFA rich), Sunflower oil (SNO, n-6 PUFA rich) or Linseed oil (LSO, n-3 PUFA rich) and nanoemulsions were prepared after mixing with Lipoid™ using high pressure homogenizer. The nanoemulsions were fed to weaning rats for 60 days along with AIN-93 diets. Rats fed nanoemulsion containing curcumin in LSO showed high levels of curcumin in serum liver, heart and brain. Significant increase in DHA levels of serum and tissue lipids were observed in rats given LSO with curcumin in nanoemulsions. Therefore, supplementation of diets with ALA rich LSO and curcumin could increase DHA concentrations in serum, liver, heart and brain lipids which have implications for meeting the DHA requirements of vegetarian populations.