title: Interactions in the postprandial appearance of beta-carotene and canthaxanthin in plasma triacylglycerol-rich lipoproteins in humans.
abstract: We investigated the plasma appearance of beta-carotene and canthaxanthin, an oxycarotenoid, in normolipidemic premenopausal women (n = 9) who ingested beta-carotene alone, canthaxanthin alone, and a combined dose. Blood samples were taken hourly for 12 h; additional blood samples were collected over 528 h. In a subset of the women (n = 5), plasma lipoproteins were separated into chylomicrons, very-low-density-lipoproteins (VLDL) subfractions, intermediate-density lipoproteins (IDLs), and low-density lipoproteins (LDLs). The appearance of beta-carotene in plasma was biphasic, with a minor peak at 5 h followed by a sustained peak at 24-48 h. The plasma appearance of canthaxanthin was monophasic, with a rapid increase to the final hourly measurement at 12 h and a steady decrease from the next measurement at 24 h. At 6 h, 23.4 +/- 2.9% of the increase in plasma canthaxanthin was associated with LDL, in contrast with 2.4 +/- 1.4% of the increase in plasma beta-carotene (P < 0.005). Ingestion of a combined dose of beta-carotene and canthaxanthin inhibited the appearance of canthaxanthin in plasma, chylomicrons, and each VLDL subfraction (P < 0.05), but did not significantly affect the rapid accumulation of canthaxanthin in LDL within 10 h. In contrast, ingestion of the combined dose did not significantly affect the appearance of beta-carotene in plasma or plasma lipoproteins. These findings suggest distinct mechanisms of incorporation into lipoproteins and specific interactions of beta-carotene and canthaxanthin during intestinal absorption in humans.
authors.affiliation: Department of Food Science and Human Nutrition, Iowa State University, Ames 50011-1120, USA.
authors.forename: I
authors.initials: I
authors.lastname: Paetau
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: N M
authors.initials: NM
authors.lastname: Goh
authors.forename: W S
authors.initials: WS
authors.lastname: White
mesh_terms: D000284:Administration, Oral; D000328:Adult; D016644:Canthaxanthin / Q000008:administration & dosage / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D002914:Chylomicrons / Q000378:metabolism; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008074:Lipoproteins / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D010316:Particle Size; D019518:Postprandial Period / Q000502:physiology*; D017697:Premenopause / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism; D019207:beta Carotene / Q000008:administration & dosage / Q000097:blood*
chemical_list: D002914:Chylomicrons; D008074:Lipoproteins; D014280:Triglycerides; D019207:beta Carotene; D016644:Canthaxanthin