Canthaxanthin and Excess Vitamin A Alter α-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.

Canthaxanthin Supplementation Alters Antioxidant Enzymes and Iron Concentration in Liver of Balb/c Mice

“…A significantly greater iron concentration was observed in liver of mice treated with canthaxanthin than in controls. This is inconsistent with the observation of Blakely et al (1991), who reported that canthaxanthin feeding lowered liver nonheme iron concentrations in rats. This difference may be due to the different doses of canthaxanthin as well as to the different animal model.…”

“…This difference may be due to the different doses of canthaxanthin as well as to the different animal model. Blakely et al (1991) supplemented canthaxanthin to the diet of rats for 8 wk, but at a much higher canthaxanthin concentration [2 g/kg diet, which corresponds to an oral dose of ϳ100 g/(g body wt⅐d) estimated from food intakes and body weights] than that administered by gavage to mice in this study. In contrast, it has been shown recently that vitamin A (from 0.37 to 2.78 mol/100 g cereal) and ␤-car-…”

“…Although oral carotenoid supplementation can reduce or increase plasma and tissue levels of tocopherols in animals (Bendich and Shapiro 1986, Blakely et al 1991, Lambert et al 1994, Mayne and Parker 1989, Tang et al 1995, Woodall et al 1996, Xu et al 1992) and humans (Mobarhan et al 1994, Xu et al 1992, few studies exist on the effect of carotenoids on cell antioxidant status in vivo.…”

High dietary vitamin A interferes with tissue α-tocopherol concentrations in fattening pigs: a study that examines administration and withdrawal times

“…On the other hand, there is evidence that high dietary vitamin A (dVitA) levels may affect vitamin E absorption and accumulation in chicks (Abawi and Sullivan, 1989;Blakely et al, 1991), young humans (Drott et al, 1993) and weanling pigs (Ching et al, 2002). However, no consistent information exists in growing-finishing pigs.…”

Effect of injected vitamin A and level of dietary vitamin E on α-tocopherol status in gestating swine

“…There is evidence from studies with chicks and laboratory rats that very high dietary vitamin A (eg, 100 x requirement) may interfere with both vitamin E absorption and blood a-tocopherol concentration (Abawi and Sullivan, 1989;Blakely et al, 1991). The (Jensen et al, 1988;Asghar et al, 1991;Mahan, 1991;Anderson et al, 1995a, b (Blomhoff et al, 1990).…”