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At least 19 recordsLinked to original sources
PubMed1992

Antioxidant activity of xanthophylls on peroxyl radical-mediated phospholipid peroxidation.

The ability of xanthophylls (canthaxanthin, zeaxanthin, and astaxanthin) as chain-breaking antioxidants was investigated in peroxyl radical-mediated peroxidation of phosphatidylcholine (PC) liposomes under atmospheric conditions using lipid-soluble and water-soluble radical generators. These xanthophylls retarded the chain propagation reaction of phosphatidylcholine hydroperoxides (PC-OOH) formation, although their activities to trap chain-carrying peroxyl radical were much less than that of alpha-tocopherol. In chick plasma studies, it was observed that endogenious xanthophylls participated in the antioxidant defenses against the attack of aqueous peroxyl radical. It was concluded that xanthophylls possess the ability to act as chain-breaking antioxidants in the peroxidation of membraneous phospholipids. Dietary xanthophylls may, therefore, be helpful in resisting membraneous phospholipids against oxidative damage in vivo.

Animals↗
PubMed1992

Dietary supplementation with xanthophyll as an effective way of identifying low-producing broiler breeder hens.

The relationship between dietary levels of xanthophyll, the degree of pigmentation in the hen, and egg production rate was studied in commercial broiler breeders (Anak 2000). In the first study, the degree of shank and beak coloration, measured with a 15-grade Roche yolk color fan, was determined in broiler breeder pullets until 34 wk of age. Although overall body coloration decreased with age following initiation of egg production, the degree of shank coloration was two- to threefold higher than that of the beak. In the second study, Roche Carophyll-red (canthaxanthin, 10%) was supplemented at levels of 0, 10, and 20 mg/kg in a corn and soybean diet containing xanthophyll, and given to hens for a period of 4 wk beginning at 55 wk of age. Increasing dietary canthaxanthin levels increased pigmentation of beak and egg yolk in a quadratic manner, whereas pigmentation increased linearly in the shank. The production rate was inversely related to the degree of shank and beak pigmentation. In a third study, the relationship between hen pigmentation (using Carophyll-red, 30 mg/kg of diet) and production rate was examined in a commercial flock of broiler breeder hens. Hens were sampled according to shank coloration (Grades 1 to 3) and egg production was monitored. The production rate of hens with high coloration was significantly lower (by approximately 33%) than the flock average. At peak production, shank pigmentation was too low to differentiate visually between degrees of coloration. Dietary supplementation of 5% corn gluten meal increased shank pigmentation and enabled efficient identification of the nonlaying hens.

Animal Feed↗
PubMed1990

Orientation of xanthophylls in phosphatidylcholine multibilayers.

Oriented multibilayers of dimyristoyl phosphatidylcholine (DMPC) modified with violaxanthin or zeaxanthin were examined by X-ray diffractometry and linear dichroism. It appears that pigment molecules and the normal to the bilayer plane form an angle of 24-25 degrees. It was also observed that rather small concentrations of added xanthophylls (molar fraction up to 3%) increase the pigmented bilayer thickness by a value of about 2 A as compared with that of the pure DMPC bilayer. The observed nonzero linear dichroism at normal incidence of light suggests the possibility of nonhomogeneous orientation of transition dipoles in the plane of the bilayer.

Carotenoids↗
PubMed1991

A simple model describing the kinetics of the xanthophyll cycle.

A new kinetic model of the xanthophyll cycle is proposed. The model is based on the assumption that the light-dependent interconversion of the so-called available and unavailable violaxanthin constitutes the rate-limiting process of the cycle at intermediate, non-saturating light intensities. This assumption, together with the known properties of violaxanthin de-epoxidase, explains all specific features of the experimental facts.

Carotenoids↗
PubMed1991

Relationship between serum xanthophyll levels and the consumption of cigarettes, alcohol or foods in healthy inhabitants of Japan.

The relationship between serum concentrations of beta-cryptoxanthin and zeaxanthin and the consumption of cigarettes and alcohol or the intake frequencies of foods was investigated in 775 Japanese inhabitants. Serum concentrations of beta-cryptoxanthin and beta-carotene in healthy Japanese aged 40-70 years were higher in females than in males. Serum beta-cryptoxanthin levels were inversely associated with the consumption of cigarettes and alcohol, as were the serum beta-carotene levels. Serum zeaxanthin (including lutein) levels were associated with cigarette consumption. The levels of serum beta-cryptoxanthin were positively correlated with the intake frequency of some fruits, and those of zeaxanthin, with the intake frequency of green vegetables, milk and eggs. These xanthophylls may play a role with beta-carotene in smoking-related cancer prevention.

Adult↗
PubMed1988

Influence of source and physical form of xanthophyll pigment on broiler pigmentation and performance.

Two experiments were conducted using 21-day-old, commercial-strain broilers to determine the effect of various commercial pigmentation products on pigmentation and bird performance. Birds received finisher/withdrawal diets that included 8% corn gluten meal or either a 2.5 or 5.0% substitution of gluten meal with Liquid OroGlo5, Dry Oroglo10, or Cromophyl-oro. When birds were slaughtered at either 48 or 51 days of age there were no differences in the birds' breast skin hue (dominant wavelength) or brightness (luminosity). Data indicated similar levels of pigmentation among birds in all treatments. Color intensity (excitation purity) values of shank and breast skin samples suggested that the liquid form of OroGlo was more effective than the dry form in pigmenting broiler skin when both forms were fed at equal calculated levels. Data indicated that actual xanthophyll intake was higher when the liquid source was fed. Body weight gain and feed efficiency among the treatments, in general, indicated that commercial pigment sources can be substituted for corn gluten meal without appreciably altering broiler performance.

Animals↗
PubMed1990

A lack of fluctuation in xanthophyll concentrations in blood in laying hens at night and absence of pigmentation rings in the yolk.

Alternate white and yellow layers in the yolk are described in most textbooks. However, it was impossible to distinguish the presence of these layers when hard-cooked yolks from hens fed commercial type diets were examined. Serum xanthophyll concentrations were measured at different times during a 24-h period. Concentrations did not vary significantly due to time of day.

Animals↗
PubMed1991

Galactolipid multibilayers modified with xanthophylls: orientational and diffractometric studies.

Oriented multibilayers of chloroplast galactolipids: monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) modified with violaxanthin and zeaxanthin were examined by X-ray diffractometry and linear dichroism. The results obtained suggest that zeaxanthin, in contrast to violaxanthin, has a significant ordering effect on galactolipid bilayers. The best ordered system consists of DGDG and zeaxanthin. In this case, the angle between the long axis of zeaxanthin molecule and the normal to the plane of bilayers amounts to 9 degrees and system has a periodicity of 61.7 A. The analogous angles in systems MGDG + violaxanthin, MGDG + zeaxanthin and DGDG + violaxanthin are clearly wider (35 degrees, 17 degrees and 28 degrees, respectively) but diffractograms show no distinct maxima.

Chloroplasts↗