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ABSTRACT: This study was conducted to evaluate the effects of common canthaxanthin (CC) or microencapsulated canthaxanthin (MC) combined with apo-ester (AE) on productive performance, egg yolk color and antioxidant capacity in laying hens. A total of 270 Hyline Brown laying hens at 56 wk of age were allocated to 3 groups with 6 replicates, and fed a wheat-soybean meal basal diet or the same diet supplemented with CC+AE or MC+AE at 5 mg/kg feed for each supplement. The productive performance was not affected by dietary treatments. The 2 test groups had higher (P < 0.05) yolk color score in fresh eggs than the control group, but the yolk color score of CC+AE group significantly declined (P < 0.05) with time, and a slight decline was also observed in the MC+AE group at 36 d. The MC+AE group had higher (P < 0.05) yolk color score of fried and boiled eggs than the other 2 groups. Higher (P < 0.05) feed canthaxanthin concentration was found in the MC+AE group at the end of experiment, which also had higher yolk canthaxanthin concentration in fresh eggs at 24 and 36 d as well as in fried, boiled and stored (4°C and 25°C) eggs. The 2 test groups had higher (P < 0.05) total antioxidant capacity in serum than the control group, and lower (P < 0.05) MDA content was observed in the MC+AE group. The mRNA level of cluster determinant 36 in jejunum was increased by the 2 test groups, and the same increase was also found in liver only in the MC+AE group. In conclusion, MC was more efficient in promoting yolk color and antioxidant capacity than CC when combined with AE.

ABSTRACT: Canthaxanthin is widely used as a feed additive to improve skin and yolk color in poultry. It is insoluble in water and sensitive to oxidation, so commercial canthaxanthin is often microencapsulated with wall materials to improve its solubility and stability. The objective of this study was to evaluate the effects of canthaxanthin microencapsulation on yolk color and canthaxanthin deposition in egg yolk of laying hens. A total of 288 Hyline Brown laying hens (48 wk of age) were allocated to 4 groups with 6 replicates of 12 hens each, and fed a basal diet or the basal diet supplemented with 5 mg/kg canthaxanthin microencapsulated with modified starch (CMMS), gelatin (CMG), and sodium lignosulfonate (CMSL), respectively. Canthaxanthin supplementation did not affect laying performance of hens, but improved (P < 0.05) yolk color of fresh, fried, boiled, and stored (4 and 25°C) eggs. The improvement of yolk color of fresh eggs was greatest in the CMSL group and least in the CMG group (P < 0.05). Both CMMS and CMSL resulted in higher (P < 0.05) yolk canthaxanthin concentration than CMG. The CMSL resulted in higher (P < 0.05) yolk color score of fried eggs than CMMS and CMG and higher (P < 0.05) yolk color score of boiled eggs than CMG, but no difference was observed in stored eggs among three canthaxanthin groups. In conclusion, CMMS and CMSL were more effective in yolk pigmentation than CMG, and CMSL was slightly better than CMMS.

This study was conducted to evaluate the effects of common canthaxanthin (CC) or microencapsulated canthaxanthin (MC) combined with apo-ester (AE) on productive performance, egg yolk color and antioxidant capacity in laying hens. A total of 270 Hyline Brown laying hens at 56 wk of age were allocated to 3 groups with 6 replicates, and fed a wheat-soybean meal basal diet or the same diet supplemented with CC+AE or MC+AE at 5 mg/kg feed for each supplement. The productive performance was not affected by dietary treatments. The 2 test groups had higher (P < 0.05) yolk color score in fresh eggs than the control group, but the yolk color score of CC+AE group significantly declined (P < 0.05) with time, and a slight decline was also observed in the MC+AE group at 36 d. The MC+AE group had higher (P < 0.05) yolk color score of fried and boiled eggs than the other 2 groups. Higher (P < 0.05) feed canthaxanthin concentration was found in the MC+AE group at the end of experiment, which also had higher yolk canthaxanthin concentration in fresh eggs at 24 and 36 d as well as in fried, boiled and stored (4°C and 25°C) eggs. The 2 test groups had higher (P < 0.05) total antioxidant capacity in serum than the control group, and lower (P < 0.05) MDA content was observed in the MC+AE group. The mRNA level of cluster determinant 36 in jejunum was increased by the 2 test groups, and the same increase was also found in liver only in the MC+AE group. In conclusion, MC was more efficient in promoting yolk color and antioxidant capacity than CC when combined with AE., Competing Interests: DISCLOSURES We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the content of this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Carotenoids perform multifaceted roles in life ranging from coloration over light harvesting to photoprotection. The Orange Carotenoid Protein (OCP), a light-driven photoswitch involved in cyanobacterial photoprotection, accommodates a ketocarotenoid vital for its function. OCP extracts its ketocarotenoid directly from membranes, or accepts it from homologs of its C-terminal domain (CTDH). The CTDH from Anabaena (AnaCTDH) was shown to be important for carotenoid transfer and delivery from/to membranes. The C-terminal tail of AnaCTDH is a critical structural element likely serving as a gatekeeper and facilitator of carotenoid uptake from membranes. We investigated the impact of amino acid substitutions within the AnaCTDH-CTT on echinenone and canthaxanthin uptake from DOPC and DMPG liposomes. The transfer rate was uniformly reduced for substitutions of Arg-137 and Arg-138 to Gln or Ala, and depended on the lipid type, indicating a weaker interaction particularly with the lipid head group. Our results further suggest that Glu-132 has a membrane-anchoring effect on the PC lipids, specifically at the choline motif as inferred from the strongly different effects of the CTT variants on the extraction from the two liposome types. The substitution of Pro-130 by Gly suggests that the CTT is perpendicular to both the membrane and the main AnaCTDH protein during carotenoid extraction. Finally, the simultaneous mutation of Leu-133, Leu-134 and Leu-136 for alanines showed that the hydrophobicity of the CTT is crucial for carotenoid uptake. Since some substitutions accelerated carotenoid transfer into AnaCTDH while others slowed it down, carotenoprotein properties can be engineered toward the requirements of applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Photodamage to the photosynthetic apparatus by excessive light radiation has led to the evolution of a variety of energy dissipation mechanisms. A mechanism that exists in some cyanobacterial species, enables non-photochemical quenching of excitation energy within the phycobilisome (PBS) antenna complex by the Orange Carotenoid Protein (OCP). The OCP contains an active N-terminal domain (NTD) and a regulatory C-terminal domain (CTD). Some cyanobacteria also have genes encoding for homologs to both the CTD (CTDH) and the NTD (referred to as helical carotenoid proteins, HCP). The CTDH facilitates uptake of carotenoids from the thylakoid membranes to be transferred to the HCPs. Holo-HCPs exhibit diverse functionalities such as carotenoid carriers, singlet oxygen quenchers, and in the case of HCP4, constitutive OCP-like energy quenching. Here, we present the first crystal structure of the holo-HCP4 binding canthaxanthin molecule and an improved structure of the apo-CTDH from Anabaena sp. PCC 7120. We propose here models of the binding of the HCP4 to the PBS and the associated energy quenching mechanism. Our results show that the presence of the carotenoid is essential for fluorescence quenching. We also examined interactions within OCP-like species, including HCP4 and CTDH, providing the basis for mechanisms of carotenoid transfer from CTDH to HCPs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Carotenoids are pigments of diverse functions ranging from coloration over light-harvesting to photoprotection. Yet, the number of carotenoid-binding proteins, which mobilize these pigments in physiological media, is limited, and the mechanisms of carotenoid mobilization are still not well understood. The same applies for the determinants of carotenoid uptake from membranes into carotenoproteins, especially regarding the dependence on the chemical properties of membrane lipids. Here, we investigate xanthophyll uptake capacity and kinetics of a paradigmatic carotenoid-binding protein, the homolog of the Orange Carotenoid Protein's C-terminal domain from Anabaena sp. PCC 7120 (AnaCTDH), using liposomes formed from defined lipid species and loaded with canthaxanthin (CAN) and echinenone (ECN), respectively. Phospholipids with different chain length and degree of saturation were investigated. The composition of carotenoid-loaded liposomes directly affected the incorporation yield and storage ratio of CAN and ECN as well as the rate of carotenoid uptake by AnaCTDH. Generally, saturated PC lipids were identified as unsuitable, and a high phase transition temperature of the lipids negatively affected the carotenoid incorporation and storage yield. For efficient carotenoid transfer, the velocity increases with increasing chain length or membrane thickness. An average transfer yield of 93 % and 43 % were obtained for the formation of AnaCTDH(CAN) and AnaCTDH(ECN) holoproteins, respectively. In summary, the most suitable lipids for the formation of AnaCTDH(CAN/ECN) holoproteins by carotenoid transfer from artificial liposomes are phosphatidylcholine (18:1) and phosphatidylglycerol (14:0). Thus, these two lipids provide the best conditions for further investigation of lipid-protein interaction and the carotenoid uptake process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Cyanobacterial blooms are increasing in frequency and intensity globally, impacting lake ecosystem health and posing a risk to human and animal health due to the toxins they can produce. Cyanobacterial pigments preserved in lake sediments provide a useful means of understanding the changes that have led to cyanobacterial blooms in lakes. However, there is some uncertainty as to whether specific carotenoids are unique to certain genera or types of cyanobacteria. To fill this knowledge gap, we analyzed pigments in 34 cyanobacteria cultures and applied the findings to sediments from three New Zealand lakes. The cyanobacterial carotenoids canthaxanthin, echinenone and zeaxanthin were detected in all cultures, whereas myxoxanthophyll was only detected in ten cultures (Microcoleus, Planktothrix and the picocyanobacteria cultures; Synechococcaceae). The sum of the individual carotenoid concentrations provided the strongest relationship with cyanobacterial biomass (R 2  = 0.58) and could be used in paleolimnology studies to evaluate general cyanobacterial abundance. Ratios of canthaxanthin, zeaxanthin and myxoxanthophyll relative to echinenone indicated that carotenoid ratios could be used to differentiate picocyanobacteria and bloom-forming cyanobacteria, to some degree. High zeaxanthin/echinenone ratios were measured in picocyanobacteria and low zeaxanthin/echinenone ratios were measured in bloom-forming cyanobacteria. The zeaxanthin/echinenone ratio was applied to sediment core samples where the cyanobacterial community was also evaluated by 16S rRNA gene metabarcoding, with the zeaxanthin/echinenone ratios showing similar patterns to those observed in the cultures. The preliminary assessment described here suggests that zeaxanthin/echinenone ratios could provide a valuable paleoecological proxy for evaluating historical shifts in cyanobacterial communities and warrants further exploration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The contents of astaxanthin, canthaxanthin and astaxanthin esters were studied in natural populations of the copepod Acartia bifilosa from the Pomeranian Bay and Gulf of Gdansk in the southern Baltic Sea. Samples dominated by any one of three developmental groups: (1) nauplii, (2) copepodids I-III and (3) copepodids IV-V and adults of Acartia bifilosa were analysed by means of high performance liquid chromatography (HPLC). As ontogenetic development progressed, significant changes occurred in the proportion of particular pigments in the total pigment pool of the various developmental groups. Astaxanthin and canthaxanthin occurred in all the groups, the former being clearly dominant. However, an increasing percentage of astaxanthin esters was recorded in the copepodids I-III, and even more in the copepodids IV-V and adults group. Most probably, astaxanthin is the main pigment active in copepod lipid metabolism. Carotenoid pigments in copepods very likely act as efficient free-electron quenchers and may be involved as antioxidants in rapid lipid metabolism. The exogenously feeding stages (late nauplii and copepodids) transform plant carotenoids taken from food and are evidently capable of metabolising astaxanthin by esterification and further degradation. It is emphasised that, according to literature data, astaxanthin esters may have an even higher quenching ability. It is suggested that crustacean carotenoid pigments, with their electron donor-acceptor abilities, may replace oxygen in peroxidation processes connected with lipid metabolism. The consequences of such a physiological role of astaxanthin for present-day estimations of energy balances in zooplankton communities are mentioned.

Canthaxanthin is widely used as a feed additive to improve skin and yolk color in poultry. It is insoluble in water and sensitive to oxidation, so commercial canthaxanthin is often microencapsulated with wall materials to improve its solubility and stability. The objective of this study was to evaluate the effects of canthaxanthin microencapsulation on yolk color and canthaxanthin deposition in egg yolk of laying hens. A total of 288 Hyline Brown laying hens (48 wk of age) were allocated to 4 groups with 6 replicates of 12 hens each, and fed a basal diet or the basal diet supplemented with 5 mg/kg canthaxanthin microencapsulated with modified starch (CMMS), gelatin (CMG), and sodium lignosulfonate (CMSL), respectively. Canthaxanthin supplementation did not affect laying performance of hens, but improved (P < 0.05) yolk color of fresh, fried, boiled, and stored (4 and 25°C) eggs. The improvement of yolk color of fresh eggs was greatest in the CMSL group and least in the CMG group (P < 0.05). Both CMMS and CMSL resulted in higher (P < 0.05) yolk canthaxanthin concentration than CMG. The CMSL resulted in higher (P < 0.05) yolk color score of fried eggs than CMMS and CMG and higher (P < 0.05) yolk color score of boiled eggs than CMG, but no difference was observed in stored eggs among three canthaxanthin groups. In conclusion, CMMS and CMSL were more effective in yolk pigmentation than CMG, and CMSL was slightly better than CMMS., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Canthaxanthin (CX) is an orange-red keto-carotenoid with high antioxidant activity. This functional pigment is sensitive to oxygen, light, pH and heat. In this study, CX was produced by the Dietzia natronolimnaea HS-1 and was encapsulated in Alginate (Alg) and Alg-high methoxyl pectin (HMP) through O/W/O multiple emulsion/external gelation method to developed resistant microparticles among acidic and neutral pHs. Results showed that initial CX concentration had a significant influence on total CX (TCX), surface CX (SCX), microencapsulation efficiency (EE) and particles size. The highest EE% for Alg (60.21 ± 0.18) and Alg-HMP (70.60 ± 0.68) were obtained with CX initial concentration of 11 and 18 μg/mg, respectively. Alg microparticles showed smaller size compare to Alg-HMP microcapsules. Presence of CX in microparticles and good antioxidant activity was confirmed by FT-IR spectroscopy and DPPH assay, respectively. CX in vitro release was 66% and 49% in acidic condition and 76% and 50% in neutral condition for Alg and Alg-HMP, respectively. Thus, Alg-HMP-CX 18 microparticles were selected to be used in both neutral and acidic foods such as milk and fermented milks products as an antioxidant and a colorant agent., (Copyright © 2018. Published by Elsevier B.V.)

Cellulosic nanocrystals from different origins were made to stabilize the canthaxanthin (CTX) in pickering emulsion. Nanocrystals were obtained by hydrochloric acid hydrolysis. Dynamic light scattering (DLS) demonstrated that the length of solid particles were in the range of 112nm-4000nm. AFM indicated the needle-like shape of the cotton cellulose nanocrystals (CCNs) and bacterial cellulose nanocrystals (BCNs) and also illustrated the thickness of the particles to be 6 and 7nm respectively. The crystallinity of both BCNs and CCNs was higher than the cellulose source they were isolated (CL: 75.4%, CCNs: 86.6; BC: 79.2%, BCNs: 88.5%). Effects of different factors such as temperature, pH and ionic concentration on stability were investigated. The results revealed that an increase in both temperature and pH was accompanied by an improvement in emulsion stability in all tested samples. However, increase in ionic concentration resulted in emulsions with less stability. In all the samples, CCN emulsions had better stability than the BCN emulsions, which was associated to smaller particle size and more coverage ability. Test of stability to light showed that CCN emulsions can preserve CTX better than BCN against the light., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A meta-analysis was conducted to evaluate the effect of the carotenoid canthaxanthin on production performance in layer hens. The data set contained 576 performance measurements from 34 trials. The trials were all conducted according to a similar experimental protocol from 1997 to 2012. The age of the animals ranged from 21 to 65 weeks. The experimental diets were predominantly wheat/SBM based, fed in mash form ad libitum. Depending on the trial and the treatment group considered, canthaxanthin supplementation was in the range of 0 to 8 mg/kg of feed.Using a linear mixed model regression applied to all 34 trials simultaneously, significant dose-dependent increases were found in egg yolk mass (+0.53% per ppm of canthaxanthin inclusion in the feed, P < 0.001), in egg mass (+0.47% per ppm, P = 0.0132), egg weight (+0.17% per ppm, P = 0.046), and in feed intake (+0.32% per ppm, P = 0.0054). A numerical increase was found in egg production (+0.28%, P = 0.14). The FCR decreased numerically (-0.24% per ppm, P = 0.36). The deposition of canthaxanthin in the egg yolk was 2.25 ppm per ppm of canthaxanthin in the feed (P < 0.001). It is concluded that in addition to egg yolk pigmentation, antioxidant effect, enhanced reproduction, and immune-modulation, canthaxanthin can significantly increase egg mass, thereby enhancing the productivity of the flock. Mechanisms relating to carotenoid metabolism and functions in avian species are a new research area that will require further investigation to explain the observed effects., (© 2017 Poultry Science Association Inc.)

Hen age and nutrition influence chick innate immunity. The immunomodulatory antioxidant carotenoid canthaxanthin is transferred from the hen diet to the egg. Antioxidants could protect the chick from bactericidal oxidative species produced by the immune system. Broiler breeder hen diets were supplemented with 0 (Control), 6 (Low), or 12 (High) mg/kg canthaxanthin. Chick early growth and ex vivo innate immunity were measured at 31 to 33 (Early), 45 to 47 (Mid), and 57 to 59 (Late) wk of hen age. Escherichia coli (E. coli) bactericidal capacity, phagocyte activation (number of phagocytes containing at least one E. coli), phagocytic capacity (number of phagocytes containing one or more E. coli), and oxidative burst at 1 and 4 d of age were determined. Egg and chick liver canthaxanthin and chick plasma total antioxidant capacity were measured. Differences were considered significant at P ≤ 0.05. Breeder productivity was greatest for the Low hens; diet did not affect egg yolk, albumen, or shell proportions. Egg canthaxanthin increased with maternal supplementation and plateaued after 28 days, but was not affected by hen age. Chick liver canthaxanthin increased with maternal supplementation, but decreased as hens aged. Hen diet did not affect broiler chick performance to 21 days of age. Maternal canthaxanthin at 6 mg/kg increased chick E. coli bactericidal capacity and d 1 oxidative burst; phagocytosis was unaffected. E. coli bactericidal capacity decreased as hens aged, but increased from 1 to 4 d, indicating maturation of chick innate immunity. Plasma total antioxidant capacity at d 1 increased with maternal canthaxanthin in chicks from Mid and Late hens. Canthaxanthin possesses immuno-modulatory and antioxidant properties, and hen age affected chick innate immune development. Single-comb White Leghorn hens were fed the same levels of canthaxanthin to determine the rate of incorporation into eggs. Egg canthaxanthin reached a plateau after 7 d. Canthaxanthin in the hen diet at 6 mg/kg resulted in the greatest positive effect on hen performance, with little effect on the chick., (© 2016 Poultry Science Association Inc.)

The aim of study was to evaluate the effect on broiler breeders fed with corn or sorghum diets and canthaxanthin on lipid peroxidation, fatty acid, and offspring's performance. A total of 440 females with similar body weight (BW) (3.77 ± 0.11 kg) and 60 roosters were placed in an open-sided house with 20 pens, randomly distributed in a factorial arrangement (2 × 2). There were 4 diets of 2 ingredients; corn (CO) or sorghum (SO) and 2 levels of canthaxanthin; 6 mg/kg (CX) and 0 mg/kg (NCX) totaling five replicate pens of 22 females and 3 males each, from 45 to 65 wk old. The BW was measured every 28 days, carotenoid concentration, thiobarbituric acid reactive substances (TBARS), fatty acid profile (%) in egg yolks, and the performance from two incubations and their offspring were evaluated. The study had the same statistical design as broiler breeders, making a total of 4 groups with 10 replicate pens of 8 chicks each. The BW and mortality were not affected (P > 0.05) by diets. Egg yolks coming from the CO diet had the highest (P < 0.05) lutein (3.8 vs. 0.49 mg/kg) and zeaxanthin (4.25 vs. 0.22 mg/kg) concentration compared to SO diet. The SO+CX diet had the highest CX concentration (P < 0.0001). The SO+CX diet showed the lowest TBARS (P = 0.0002) in the egg yolk compared to the CO+CX diet. Egg yolks coming from breeders fed with CO showed a higher concentration of saturated fatty acids (23.36 vs. 21.44%) and monounsaturated fatty acids (27.17 vs. 24.96%). Egg yolks arising from broiler breeders fed with SO diets showed a higher concentration of polyunsaturated fatty acids compared (15.29 vs. 12.88%). The CX reduced the offspring CO diets mortality and improved their viability at 64 wk-old for the broiler breeders (P < 0.05). CX was well absorbed from the diet and effectively transferred to the egg yolk, thereby increasing its concentration in the yolk. This conferred resistance to oxidative stress to the yolk and also later to the developing embryo and its ultimate performance., (© 2016 Poultry Science Association Inc.)

This study evaluated the effects of dietary canthaxanthin (CX) and 25-hydroxycholecalciferol (25-OH-D3) supplementation on the antioxidant status and tibia quality of duck breeders and newly hatched ducklings. In total, 780 female and 156 male duck breeders were randomly allotted to 2 treatments. Duck breeders were fed either a commercial diet (containing 3,000 IU/kg vitamin D3) or the same diet plus a mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg) for 40 wk. The antioxidant status of duck breeders, egg yolk, and ducklings; tibia quality of duck breeders and ducklings; and shell quality of breeder eggs were investigated. The total antioxidant capacity of breeder female liver (P = 0.028), breeder male testis (P = 0.049), egg yolk (P = 0.032), one-day-old duckling liver (P = 0.024), and one-day-old duckling yolk sac (P = 0.012) were increased by dietary supplementation of the mixture of CX and 25-OH-D3 The inclusion of CX and 25-OH-D3 decreased liver protein carbonyl of breeder females (P = 0.030), and liver malonaldehyde (P = 0.050) and protein carbonyl (P = 0.030) of breeder males. Yolk (P < 0.001), shank (P < 0.001), and yolk sac pigmentation (P < 0.001) of one-day-old ducklings were increased by the supplementation of the CX and 25-OH-D3 mixture. No differences (P > 0.05) were observed in tibia quality or eggshell quality between treatments. In conclusion, the inclusion of the mixture of CX and 25-OH-D3 in a diet sufficient in vitamin D3 increased antioxidant status but not tibia quality of duck breeders and newly hatched ducklings., (© 2016 Poultry Science Association Inc.)

This trial studied the effects of maternal dietary vitamin premixes, and the mixture of canthaxanthin (CX) and 25-hydroxycholecalciferol (25-OH-D3) on the performance of progeny ducklings. Four maternal diets were used under a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes (Regular and High; High premix had higher levels of all vitamins except K3 than the Regular premix), and with or without the addition of the mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg). Cherry Valley duck breeders (38-wk-old) were fed with corn-wheat flour-soybean meal-based diets for 8 wk, and then eggs were collected and hatched. Healthy ducklings (equal number of female and male) from each maternal group were randomly selected and received the same commercial starter (1 to 14 d) and grower (15 to 35 d) pellet diet for 35 d. Maternal High vitamin premix increased shank pigmentation (1 d, P = 0.001), BW (1 d, P < 0.001 and 14 d, P = 0.006), BW gain (1 to 14 d, P = 0.008), G:F ratio (1 to 14 d, P = 0.007), superoxide dismutase (SOD; 1 d liver, P = 0.027 and 14 d serum, P = 0.031), and total antioxidant capacity (1 d liver, P < 0.001); and decreased protein carbonyl (14 d serum, P = 0.011) of ducklings. The mixture of CX and 25-OH-D3 increased yolk pigmentation (P < 0.001); increased shank pigmentation (1 d, P < 0.001 and 14 d, P < 0.001), BW (1 d, P < 0.001), feed intake (15-35 d, P = 0.014), SOD (1 d liver, P = 0.032), and tibia ash (14 d, P = 0.010) of ducklings; and decreased malondialdehyde (P < 0.001) and protein carbonyl (P = 0.044) of yolks, and malondialdehyde (14 d serum, P < 0.001) of ducklings. In conclusion, either maternal High vitamin premix or maternal supplementation of the CX and 25-OH-D3 mixture improves growth performance and antioxidant status of ducklings., (© 2016 Poultry Science Association Inc.)

In order to discuss the effect of chemical structure on photocatalysis efficiency, the photocatalytic degradation of three commercial textile dyes (C.I. Acid Orange 10 (AO10), C.I. Acid Orange 12 (AO12) and C.I. Acid Orange 8 (AO8)) with different structure and different substitute groups has been investigated using supported TiO(2) photocatalyst under UV light irradiation. All the experiments were performed in a circulation photochemical reactor equipped with a 15-W UV lamp emitted around 365nm. The investigated photocatalyst was industrial Millennium PC-500 (crystallites mean size 5-10nm) immobilized on glass plates by a heat attachment method. SEM images of the immobilized TiO(2) nanoparticles showed the good coating on the plates, after repeating the deposition procedure three times. Our results indicated that the photocatalytic decolorization kinetics of the dyes were in the order of AO10>AO12>AO8. Photocatalytic mineralization of the dyes was monitored by total organic carbon (TOC) decrease, changes in UV-vis spectra and ammonium ion formation. The dye solutions could be completely decolorized and effectively mineralized, with an average overall TOC removal larger than 94% for a photocatalytic reaction time of 6h. The nitrogen-to-nitrogen double bond of the azo dyes was transformed predominantly into NH(4)(+) ion. The kinetic of photocatalytic decolorization of the dyes was found to follow a first-order rate law. The photocatalysis efficiency was evaluated by figure-of-merit electrical energy per order (E(EO)).

Using benzo(a)pyrene (BaP) metabolism as a probe for chemical carcinogenesis, in vitro and in vivo effects of palm-oil carotenoid [beta-carotene (BC), alpha-carotene (AC), or canthaxanthin (CTX)] on BaP metabolism in the rat hepatic cytochrome P450-mediated monooxygenase system were studied. Apparent Michaelis-Menten constants (Km) for formation of the precursor carcinogen, 7,8-dihydrodiol BaP, were found to be 14.4 (BC), 1.74 (AC), and 0.7 (CTX) mumol/L. The order of anticarcinogenic strength established in this study was BC much greater than AC greater than CTX. Increased formation of the detoxification intermediate, 3-hydroxy BaP, with increased carotenoid concentration was observed. The order of detoxification strength was BC greater than AC = CTX. The presence of carotenoids in vivo inhibited BaP metabolism. Using 9,10-dihydrodiol BaP as an indicator for inhibition, the order of the antioxidative activity was palm oil (with carotenoids) greater than BC greater than CTX greater than palm oil (without carotenoids). BC and AC may selectively modify the rat-liver microsomal enzymes, thus providing a biochemical mechanism for the inhibitory effect of palm carotenoids on chemical carcinogenesis.

Serum concentrations of alpha-carotene (AC), beta-carotene (BC), lycopene (LY), beta-cryptoxanthin (CR), zeaxanthin (including lutein. ZX), canthaxanthin (CX), retinol (RE), and alpha-tocopherol (TO) in healthy persons (618 males and 1,196 females) aged 7-86 years were determined by HPLC. Serum concentrations of BC among persons aged 20-49 years were higher with increasing age in females, but not in males. Serum CR concentrations decreased with age ranging from 7 to 39 years, while ZX concentrations rose in the age group of 20 to 59 years for both sexes. In contrast, serum RE concentrations and ratios of RE/BC and RE/CR, especially in males aged 20-49, were higher with age. Serum TO values in both sexes rose with age and were similar.

The absorption and distribution of [14C]-canthaxanthin and [14C]lycopene were studied in rats and in rhesus monkeys following the oral administration of [14C]canthaxanthin or [14C]lycopene in olive oil supplemented with 1 mg alpha-tocopherol/mL. For canthaxanthin and lycopene, peak accumulation of radioactivity in plasma occurred between 4 and 8 h in rats and between 8 and 48 h in monkeys. In rats, the liver contained the largest amount of both kinds of radioactive pigments. In monkeys, with the exception of one stomach sample, liver was also the major depot organ for both canthaxanthin and lycopene. The other organs tested accumulated various amounts of pigment. No labeled metabolic products of either canthaxanthin or lycopene were found.

Antioxidants were found to protect against the genotoxic effects of chemical and physical mutagenic and clastogenic agents. This study focused on the capacity of antioxidants to reduce an intrinsic and persistent chromosome instability. As a model system, strains of C127 cells, which were transformed by bovine papillomavirus (BPV) DNA and which carry BPV DNA varying from 20 to 160 copies, were used. Transformed cells of 10 different strains showed a persistently high incidence of mitotic irregularities detectable at anaphase and telophase (27.3-58.9%), an elevated frequency of cells with micronuclei (6.6-34.7%), and a broad spectrum of nuclear sizes, as measured by image analysis. A 3-day exposure to retinoic acid, retinol, beta-carotene, canthaxanthin, ascorbic acid and ellagic acid greatly reduced the degree of chromosome instability, whereas catechin, eugenol and pyrogallol showed a smaller inhibitory effect, and curcumin had no detectable effect on the frequency of mitotic irregularities. After withdrawal of retinoic acid treatment, the high levels of chromosome instability reappeared. The possibility that the protective effect of the retinoids and carotenoids examined in the model system points to their beneficial administration to human cells with an intrinsic or acquired chromosome instability is discussed.

Beta-carotene and canthaxanthin at concentrations of 70 or 300 microM were shown to inhibit the proliferation of cultured human squamous cells (SK-MES lung carcinoma and SCC-25 oral carcinoma) in a 5 hr cell density assay. Responses were similar for both tumor cell lines, ranging from 71-84% inhibition. In contrast, equimolar concentrations of alpha-tocopherol gave only 19-36% inhibition of SCC-25, but 50-75% inhibition of SK-MES cell density. Equimolar reduced glutathione resulted in 4-15% stimulation of SCC-25 and 22-25% inhibition of SK-MES cell proliferation. With cultured normal keratinocytes, treated final cell densities did not differ significantly from those of controls. Two additional assays measuring the metabolic generation of formazan (MTT assay) and [5-3H]thymidine incorporation were in substantial agreement with the growth inhibition pattern. Thus both continuous and cyclic cellular processes are involved in the tumor-specific response. Onset of the response to beta-carotene alone or in combination with alpha-tocopherol is signalled within 1-2 hours of treatment by the appearance of a unique 70 kD heat-shock protein.

Canthaxanthine, a non-provitamin A carotenoid, has been marketed in Canada since March 1979 as a skin-tanning agent. Fifty-one individuals who ingested from 3.6 to 66 g of the drug within a 24-month period were ophthalmologically evaluated. Six of them had deposits in the ocular fundus that appeared to be related to ingestion of the substance, but no functional impairment could be detected.

This article describes two patients with a bilateral maculopathy due to the presence of numerous glistening yellow particles located mainly around the edge of the macular pit. This picture has apparently not been reported before. Further studies are needed to confirm a possibly toxic origin.

A retrospective study of 14 cases of retinopathy due to canthaxanthine, a carotenoid recently used as a skin-tanning agent, revealed that several clinical factors were associated with an increased susceptibility to retinal deposits: focal epitheliopathy, ocular hypertension and, possibly, the concurrent use of beta-carotene. Age has already been established as such a factor.

A white corn-soy diet amended with varying levels (0, 5, 10, 20, 40, and 80 ppm) of canthaxanthin, a red diketocarotenoid available by chemical synthesis, and fed to young broiler chickens for 3 weeks has the attributes of a useful experimental model for the study of absorption, transport, and deposition of oxycarotenoids. On high pressure liquid chromatography of extracts of the diet and tissues of the birds, canthaxanthin predominated over the background level of nonspecific carotenoids. The concentrations of canthaxanthin found in the contents of the jejunum and large intestine and in the serum, liver, and toe web were directly proportional to the dietary concentration. Departure from such linear relationships would signal loci of action for factors affecting pigmentation. Analysis of toe webs, an integumentary depot site for carotenoids, revealed that the concentrations of canthaxanthin and two other compounds, one more polar and the other less polar than canthaxanthin, were proportional to the dietary concentration of canthaxanthin. Saponification converted the less polar compound to the more polar compound. The behavior of these compounds in response to dietary canthaxanthin, to chromatography, and to saponification can be explained by assuming that canthaxanthin, a diketocarotenoid, was partly reduced to a ketohydroxy carotenoid (hydroxyechinenone) whose hydroxyl group is acylated to form an ester. These products represent new metabolic reactions in poultry.

Canthaxanthin, (4,4'-diketo-beta,beta-carotene), a red carotenoid used to extend the dominant wavelength of the yellow pigments in the skin and egg yolk of chickens, was fed (70 micrograms/g diet) to chicks depleted of normal tissue oxycarotenoids. High performance liquid chromatography analysis of tissues from such chicks revealed that a portion of canthaxanthin was reduced to 4-hydroxyechinenone (4-hydroxy-4'-keto-beta,beta-carotene) that in turn was reduced in part to isozeaxanthin (4,4'-dihydroxy-beta,beta-carotene). The alcohols thus formed were acylated in part to 4-hydroxyechinenone monoester and isozeaxanthin monoester and diester. Individual metabolites were identified by retention times, ratios A470/A430, and stopped-flow spectral analyses, which were identical in each case to authentic standards. Ratios of canthaxanthin to metabolites varied with the tissue, but in general metabolites were concentrated in the integument.

Male Wistar Kyoto rats were fed diets containing either 2 g/kg (0.2%) beta-carotene, canthaxanthin or basal diet for up to 66 wk. Plasma and tissues were analyzed for vitamin A, vitamin E, beta-carotene or canthaxanthin levels. In vitro immune responses of splenocytes to T- and B-lymphocyte mitogens were determined. T- and B-lymphocyte responses were consistently enhanced in the groups fed beta-carotene or canthaxanthin. Since canthaxanthin cannot be converted to vitamin A, the immunoenhancement seen in these experiments is attributed to a carotenoid effect.