Use of a C tracer to quantify the plasma appearance of a physiological dose of lutein in humans

Auteur(s) :
Liang Y., Serfass RE., Trahavovsky WS., White WS., Yao LH.
Date :
Mar, 2000
Source(s) :
LIPIDS. #35:3 p339-348
Adresse :
Department of food science and human nutrition, center for designing foods to improve nutrition, and department of chemistry, iowa state university, ames, iowa 50011

Sommaire de l'article

Increased intake of lutein from vegetables promotes increased density of the macular pigment and therefore may protect against age-related macular degeneration.

Our objective was to use a C-tracer and high-precision gas chromatography-combustion interfaced-isotope ratio mass spectrometry (GC-C-IRMS) to investigate metabolism of lutein dose equivalent to that absorbed from vegetables.

Biosynthetic per-labeled (>99% C) lutein was purified from a commercially available extract of of algal biomass. Subjects (n=4) ingested 3 mg of [C] lutein with a standardized low-carotenoid breakfast. Blood samples were collected at baseline and then hourly for 12 h ; additional blood samples were drawn at 16, 24, 48, 72, 96, 192, 360, and 528 h. To produce parhydro-beta-carotene suitable for analysis by GC-C-IRMS, the plasma lutein fraction was hydrogenated on palladium-on-carbon catalyst with acid-catalyzed hydrogenolysis. The stable carbon isotope (C/C) ratio mesasured by GC-C-IRMS was used to calculate the plasma concentration of [C] lutein. There was a rapid increase in [C] lutein in plasma until peak enrichment at 16 h followed by by a decline to the next measurement at 24 h. At 528 h, small changes in C enrichment from baseline could still be measured in plasma lutein. High-precision GC-C-IRMS enables complete definition of the appearance and disappearance of [C] lutein in plasma after ingestion of a dose similar to that absorbed from foods.

Source : Pubmed