title: Canthaxanthin and excess vitamin A alter alpha-tocopherol, carotenoid and iron status in adult rats.
abstract: beta-Carotene and excess vitamin A have been shown to reduce plasma alpha-tocopherol when fed to young rats. The present study assessed the effects of beta-carotene, excess vitamin A and canthaxanthin (4,4'-diketo-beta-carotene) on carotenoid, alpha-tocopherol and iron status in adult retired breeder rats. Male 8- to 10-mo-old rats (10/group) were fed varying levels of vitamin A as retinyl palmitate, beta-carotene and canthaxanthin ad libitum for 8 wk. The AIN-76A diet was modified to contain 16% (wt/wt) fat and 50% carbohydrate (control) plus beta-carotene or canthaxanthin at 0, 0.048 (BC1 or CX1) and 0.2% (BC2 or CX2) of the diet. These compounds were fed with and without excess retinyl palmitate (RP, 220 mg/kg). Higher relative liver weights were observed in CX- and RP-fed groups. Plasma retinyl esters were detected in all RP-fed groups. Plasma retinyl palmitate was 1.6- and 1.5-fold higher in RP-BC and RP-CX groups, respectively, than in the RP groups. Plasma and liver beta-carotene and canthaxanthin were 11-54% and 26-74% lower, respectively, with excess retinyl palmitate feeding. Feeding canthaxanthin and retinyl palmitate but not beta-carotene, resulted in lower levels of plasma alpha-tocopherol. Liver non-heme iron levels were also lower in CX-fed rats irrespective of retinyl palmitate feeding. These results extend to adult rats previous findings that excess retinyl palmitate alters vitamin E and carotenoid status prior to the manifestation of clinical signs of hypervitaminosis A. Additionally, canthaxanthin feeding lowers alpha-tocopherol and iron status in adult rats.
authors.affiliation: Division of Nutrition, Food and Drug Administration, Washington, DC 20204.
authors.forename: S R
authors.initials: SR
authors.lastname: Blakely
authors.forename: G V
authors.initials: GV
authors.lastname: Mitchell
authors.forename: M Y
authors.initials: MY
authors.lastname: Jenkins
authors.forename: E
authors.initials: E
authors.lastname: Grundel
authors.forename: P
authors.initials: P
authors.lastname: Whittaker
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D016644:Canthaxanthin / Q000008:administration & dosage / Q000494:pharmacology*; D002338:Carotenoids / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D007501:Iron / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014280:Triglycerides / Q000097:blood; D014801:Vitamin A / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D014810:Vitamin E / Q000378:metabolism*
chemical_list: D014280:Triglycerides; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids; D016644:Canthaxanthin; D002784:Cholesterol; D007501:Iron