Uptake of α-linolenic acid and its conversion to long chain omega-3 fatty acids in rats fed microemulsions of linseed oil.

The present work was designed to prepare linseed oil (LSO) microemulsion and explore the possibility of enhancing the uptake and utilization of α-linolenic acid (ALA) present in LSO. The bioavailability of encapsulated LSO as against native oil was monitored in rats by measuring the uptake in vitro using the intestinal everted sac model and in-vivo administration of microemulsions of LSO to rats for a period of 30 days. Microemulsions were prepared by using different binding materials such as gum acacia, whey protein and lipoid. When LSO was encapsulated with gum acacia, whey protein and lipoid, the levels of ALA uptake into intestinal sacs was increased by 6, 17 and 28% as compared to oil given without encapsulation. EPA and DHA were not observed in the oil absorbed by intestinal everted sacs when given as emulsions with gum acacia or whey protein. When LSO was given as microemulsions with lipoid, EPA + DHA was observed in oil absorbed by intestinal sacs. Similarly when LSO was given as a lipoid emulsion by intubation to rats, the EPA and DHA in serum lipids were found to be 41 and 34 μg/ml, respectively while rats given LSO without encapsulation contained EPA and DHA at 9.1 and 8.8 μg/ml, respectively. Similar changes in omega-3 fatty acid content in liver lipids were observed when LSO was given as a microemulsion with lipoid. This study indicated that ALA was taken up and metabolized to long chain omega-3 PUFA when given as microemulsion with lipoid.