Docosahexaenoic Acid (DHA) Bioavailability in Humans after Oral Intake of DHA-Containing Triacylglycerol or the Structured Phospholipid AceDoPC®

Abstract

AceDoPC^® is a structured glycerophospholipid that targets the brain with docosahexaenoic acid (DHA) and is neuroprotective in the experimental ischemic stroke. AceDoPC^® is a stabilized form of the physiological 2-DHA-LysoPC with an acetyl group at the sn1 position; preventing the migration of DHA from the sn2 to sn1 position. In this study we aimed to know the bioavailability of ¹³C-labeled DHA after oral intake of a single dose of ¹³C-AceDoPC^®, in comparison with ¹³C-DHA in triglycerides (TAG), using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) to assess the ¹³C enrichment of DHA-containing lipids. ¹³C-DHA enrichment in plasma phospholipids was significantly higher after intake of AceDoPC^® compared with TAG-DHA, peaking after 24 h in both cases. In red cells, ¹³C-DHA enrichment in choline phospholipids was comparable from both sources of DHA, with a maximum after 72 h, whereas the ¹³C-DHA enrichment in ethanolamine phospholipids was higher from AceDoPC^® compared to TAG-DHA, and continued to increase after 144 h. Overall, our study indicates that DHA from AceDoPC^® is more efficient than from TAG-DHA for a sustained accumulation in red cell ethanolamine phospholipids, which has been associated with increased brain accretion.

Keywords: brain; gas chromatography combustion isotope ratio mass spectrometry; plasma phospholipids.

Figure 1

¹³C-DHA in plasma phospholipids from AceDoPC compared to TAG-DHA after 50 mg DHA intake in both esterified forms, at different times post-intake (A). Results are expressed in pmol of ¹³C-DHA per mL of plasma, presented as means ± SEM from three values. (B) represents area under curves (AUC) from Figure 1A. Stars indicate significant differences within each time, according to the student t test.

Figure 2

¹³C-DHA in red cell phospholipids after intake of ¹³C-DHA esterified in either AceDoPC or TAG. Fifty milligrams of ¹³C-DHA source were ingested, and blood samples collected at the different times shown in figures. PE & PC were separated as described in Materials & Methods. Results are expressed in pmol of ¹³C-DHA per mL of blood, presented as ± SEM from three values. (A) relates to ¹³C-DHA incorporation into red cell PC+PE. (B,C) relate to separate phospholipids PC and PE, respectively.