Roe-derived phospholipid administration enhances lymphatic docosahexaenoic acid-containing phospholipid absorption in unanesthetized rats

Plasma n-3 fatty acids are important as the supplying pool of n-3 fatty acids to various tissues including the brain, although the relationship between dietary n-3 fatty acids and their molecular species in the plasma are not fully clarified. We investigated the intestinal absorption of docosahexaenoic acid (DHA) derived from fish roe phospholipid (Roe-PL) and compared it with fish oil triacylglycerol and free DHA using unanesthetized lymph-cannulated rats. The DHA absorption from intraduodenally administered three samples were not significantly different, whereas Roe-PL administration resulted in a significantly higher level of DHA in the phospholipid fraction than the other two samples administrations. DHA in Roe-PL at the sn–2 position was less hydrolyzed by pancreatin than by purified phospholipase A2 in vitro and simultaneous administration of free DHA and lysophosphatidylcholine did not produce the same results as the Roe-PL administration. Our results indicate that dietary DHA-containing phospholipid is effective to increase the systemic DHA incorporated into phospholipids via intestinal absorption and biosynthesis. •Intestinal absorption of DHA as phospholipid, triacylglycerol and free fatty acids were compared in lymph-cannulated rats.•The total DHA absorptions were not significantly different among three chemical forms of DHA.•DHA-containing phospholipid administration significantly increased DHA in lymphatic phospholipids among three samples.•Administration of free DHA with lysoPC did not mimic the results of DHA-containing phospholipid administration.•DHA at the sn-2 position of phospholipid was less subject to digestion with pancreatin than with purified pancreatic PLA2.•The low digestibility was suggested to increase the intestinal biosynthesis of DHA-containing phospholipids.