title: All-trans beta-carotene is absorbed preferentially to 9-cis beta-carotene, but the latter accumulates in the tissues of domestic ferrets (Mustela putorius puro).
abstract: The algae Dunaliella bardawil and Dunaliella salina naturally contain large concentrations of all-trans and 9-cis beta-carotene (betaC). The purpose of this study was to compare the relative serum and tissue accumulation of all-trans and 9-cis betaC in ferrets fed different ratios of all-trans/9-cis betaC derived from two commercial sources, D. bardawil or D. salina (Betatene). Male ferrets (7 wk old) were fed carotene-free, pelleted diets for 27 d. Beginning on d 18, groups of ferrets (n = 6 or 7) received daily, one of six oral supplements varying in ratios of 9-cis and all-trans betaC mixed with approximately 1.0mL of Ensure. Four supplements containing 5.2-8.3 micromol total betaC were prepared from a 20% Betatene preparation, D. bardawil, a high-cis Betatene preparation, and Betatene further enriched in 9-cis betaC with all-trans betaC/9-cis betaC ratios of 2.2, 1.5, 0.6 and 0.4, respectively. Two control supplements, high and low betaC, were prepared from commercial betaC beadlets. The high control supplement had an all-trans/9-cis ratio of 19.0, whereas 9-cis betaC was not detected in the low supplement. On d 27, serum and tissues were obtained for HPLC analysis of betaC and its isomers. Analysis of livers showed that all-trans betaC was the primary isomer present, but 9-cis and other isomers were also detected in all groups. The hepatic all-trans/9-cis ratios were 5.9, 4.9, 2.5, 1.4, 52.2 and47.5, respectively, for the groups listed above. Lower amounts of all-trans and 9-cis betaC were found in kidneys compared with the liver, but ratios of all-trans/9-cis were not different among groups. Only trace amounts of 9-cis betaC were found in serum. These results demonstrate that the algae D. bardawil and D. salina provide a bioavailable source of betaC isomers, but, as in humans, absorption of 9-cis betaC is poor and any 9-cis betaC absorbed is apparently cleared by the liver.
authors.affiliation: Department of Food Science and Human Nutrition and Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Erdman
authors.forename: A J
authors.initials: AJ
authors.lastname: Thatcher
authors.forename: N E
authors.initials: NE
authors.lastname: Hofmann
authors.forename: J D
authors.initials: JD
authors.lastname: Lederman
authors.forename: S S
authors.initials: SS
authors.lastname: Block
authors.forename: C M
authors.initials: CM
authors.lastname: Lee
authors.forename: S
authors.initials: S
authors.lastname: Mokady
mesh_terms: D000042:Absorption; D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D000460:Chlorophyta / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements; D005289:Ferrets / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D013237:Stereoisomerism; D019207:beta Carotene / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism
chemical_list: D019207:beta Carotene