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In this trial, the interaction between two different light resource and different levels of two pigments was investigated in order to determine their effects on growth and reproductive performance of the ornamental fish swordtail (Xiphophorus helleri) broodstock. Fish were fed with different levels of 50, 100 and 200 mg · kg-1 of astaxanthin or canthaxanthin, under two different light conditions (natural and artificial). The obtained results were more evident in animals fed with astaxanthin in comparison to canthaxanthin. Furthermore, swordtails reared under artificial light in comparison to the natural light source showed better performance. Overall the greatest effect was for the fish treated with medium dose of astaxanthin (100 mg.kg-1), under the artificial light conditions of rearing. Results indicated the important effects of all three factors (light source, dosage and carotenoids type), with significant interactions between the carotenoid dosage with carotenoid type and light source. [ABSTRACT FROM AUTHOR]

Canthaxanthin is a reddish-orange xanthophyll with strong antioxidant activity and higher bioavailability than carotenes, primarily used in food, cosmetics, aquaculture, and pharmaceutical industries. The spiking market for natural canthaxanthin promoted researchers toward genetic engineering of heterologous hosts for canthaxanthin production. Mucor circinelloides is a dimorphic fungus that produces β-carotene as the major carotenoid and is considered as a model organism for carotenogenic studies. In this study, canthaxanthin-producing M. circinelloides strain was developed by integrating the codon-optimized β-carotene ketolase gene (bkt) of the Haematococcus pluvialis into the genome of the fungus under the control of strong promoter zrt1. First, a basic plasmid was constructed to disrupt crgA gene, a negative regulator of carotene biosynthesis resulted in substantial β-carotene production, which served as the building block for canthaxanthin by further enzymatic reaction of the ketolase enzyme. The genetically engineered strain produced a significant amount (576 ± 28 μg/g) of canthaxanthin, which is the highest amount reported in Mucor to date. Moreover, the cell dry weight of the recombinant strain was also determined, producing up to more than 9.0 g/L, after 96 h. The mRNA expression level of bkt in the overexpressing strain was analyzed by RT-qPCR, which increased by 5.3-, 4.1-, and 3-folds at 24, 48, and 72 h, respectively, compared with the control strain. The canthaxanthin-producing M. circinelloides strain obtained in this study provided a basis for further improving the biotechnological production of canthaxanthin and suggested a useful approach for the construction of more valuable carotenoids, such as astaxanthin.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Today’s global problems and challenges have given rise to a new field of interest – bioeconomics. It is strongly related to phycoprospecting, or searching for specific algal strains of commercial importance. There has been growing interest in the small algal class Eustigmatophyceae in recent years. These microscopic stramenopilic algae, which have all the advantages of microalgal cultivation, have proved to be promising commercial sources of valuable compounds (e.g. carotenoids, unsaturated fatty acids, amino acids) in aquaculture, agriculture, biofuels production, medicine, pharmaceutics, cosmetics, wastewater treatment, environmental control, etc. The present review shows the main genera and strains of commercial importance, outlines their main fields of application and some gaps in our knowledge in this aspect. Today, the great promising bioeconomical potential of these algae has generally been recognized, but in the present state of its infancy, it is far from being fully exploited.

A bacterial strain was isolated from an oil-contaminated site and on its' further characterization, exhibited the potential of synthesising metabolites and the ability to degrade crude oil. Its' morphological, biochemical and 16S rRNA analysis suggested that the bacterium belongs to Dietzia maris AURCCBT01. This strain rapidly grew in the medium supplemented with n-alkanes C14, C18, C20, C28 and C32 utilizing them as a sole carbon source and produced a maximum canthaxanthin pigment of 971.37 µg/L in the n-C14 supplemented medium and produced the lowest pigment yield of 389.48 µg/L in the n-C-32 supplemented medium. Moreover, the strain effectively degraded 91.87% of crude oil in 7 days. The emulsification activity of the strain was 25% with the highest cell surface hydrophobicity (70.26%) and it showed a decrease in surface tension, indicating that the biosurfactant production lowers the surface tension. This is the first report on the characterization of the strain, Dietzia maris AURCCBT01 and its' novelty of alkane degradation and simultaneous production of canthaxanthin pigment. [ABSTRACT FROM AUTHOR]

Aim: Nano‐biotechnologically synthesizing silver nanoparticles via canthaxanthin pigment extracted from Dietzia maris AURCCBT01 and assessing their cytotoxic therapeutic potential against human keratinocyte cell line (HaCaT) were the key objectives of this study. Methods and Results: The pigment extracted from D. maris AURCCBT01 was identified as canthaxanthin using UV‐VIS spectroscopy, FTIR, NMR (1H NMR and 13C NMR) and MS. Canthaxanthin, treated with silver nitrate solution, produced canthaxanthin‐mediated silver nanoparticles and they were characterized by UV‐VIS spectroscopy, FTIR, XRD, FESEM‐EDX and TEM‐SAED techniques. UV‐VIS spectroscopy pointed out an absorption band at 420 nm, relating to the surface plasmon resonance of silver nanoparticles. FTIR findings suggested that the diverse functional groups of canthaxanthin bio‐molecules played a significant task in capping the silver nanoparticles. XRD analysis exhibited 40·20 nm for the crystal size of nanoparticles. FESEM and TEM exhibited that the biosynthesized silver nanoparticles were spherical in shape with crystalline nature and the particle size was 40–50 nm. Moreover, the cytotoxicity assessment of the synthesized nanoparticles in HaCaT revealed significant cytotoxicity in the cultured cells with an IC50 value of 43 µg ml−1. Conclusion: Stable silver nanoparticles synthesized using canthaxanthin from D. maris AURCCBT01 were found effective for application in wound healing activity. Significance and Impact of the Study: Biosynthesized silver nanoparticles via canthaxanthin bacterial pigment exhibited their cytotoxicity effect in HaCaT and testified their eventual therapeutic potential in the wound healing activity with no side effects in a cost effective and eco‐friendly process. [ABSTRACT FROM AUTHOR]

Background: Vitiligo is an autoimmune skin condition that affects people globally anywhere, from <0.1% to more than 8% of individuals. The disease destroys skin melanocytes, resulting in a patchy depigmentation of the skin. About 50% of all patients develop the disease before their 20s. Methods: We systematically searched the literature and reviewed the evidence for the use of nutritional supplements and diet in the management of vitiligo. Embase and Medline were searched for diet, herbal, and nutrition-based clinical studies. Additional filters were applied that looked for controlled trial or randomized controlled trial and article or article in press or letter and English and clinical study. We selected clinical studies in humans that showed how diet or natural supplements can improve the symptoms of vitiligo in all of our searches. Results: There were 62 manuscripts that resulted from the PubMed search and 259 from the Embase search. A final of 26 studies were reviewed, and other supplemental case and case-control studies were used to introduce diet components that may influence either exacerbation or amelioration of vitiligo. Possible mechanisms of action are introduced for natural and supplemental interventions. Conclusion: Some of the supplements reviewed include Gingko biloba, oral Polypodium leucotomos, alpha lipoic acid, vitamins B12, D, and E, folic acid, phenylalanine, canthaxanthin, Nigella sativa oil, and other combined herbal bio-actives. Overall, the growing evidence is promising, but more studies are needed in this area to further explore the impact that supplements and diet can have on vitiligo management. The most promising therapies included oral phenylalanine as adjuvant therapy with UVA therapy, oral G. biloba as monotherapy, both of which can be used with other traditional therapies, and oral P. leucotomos with phototherapy or photochemotherapy. [ABSTRACT FROM AUTHOR]

In this study, we studied the levels of both of the main pigments in Salmonidae—astaxanthin (Ax) and canthaxanthin (Cx)—accumulated in the liver, female gonads, and male gonads of rainbow trout (Oncorhynchus mykiss) reared in water containing the fungicide mancozeb (MZ) in concentration levels permitted by European legislation. Experimental fish were divided into three groups: the first was a control group, the second was fed with market feed (containing Ax and Cx), and the third was fed with market feed (containing Ax and Cx) and reared in environmental water containing permissible MZ levels. The diet preparation followed the manufacturer’s recommendations. The accumulated pigment quantities were measured using an HPLC-PDA method after selective extraction: Ax ranged from 2.490 ± 0.247 mg/kg (female gonads, second group) to 0.176 ± 0.007 mg/kg (liver, control group), and Cx—from 2.406 ± 0.166 mg/kg (female gonads, second group) to 0.103 ± 0.010 mg/kg (liver, control group). The pattern of the accumulation of both pigments in the three organs in the specimens of the three groups was sustainable: the amount of Ax was always greater than that of Cx, and the correlation between their concentrations was very high. The pigments were accumulated most intensively in the female gonads, followed by the male gonads and the liver. This trend was confirmed for all three experimental groups. However, the differences in the last third group were very small, and the levels of the xanthophylls accumulated were the lowest. A particular cause of the latter findings was the ongoing detoxification reactions and the disposal of MZ, in which Ax and Cx were involved as antioxidants.

The carotenogenic thraustochytrid Thraustochytrium sp. RT2316-16 was grown in batch and repeated-batch cultures using different feeds containing glucose, or glycerol, and yeast extract, for the production of lipids, phospholipids and carotenoids. RT2316-16 produced canthaxanthin, astaxanthin and β-carotene. The effects of biotin, ascorbic acid, light and temperature were evaluated in some of the experiments. In 2-day-old batch cultures, the combined mass percentage of eicosapentaenoic acid and docosahexaenoic acid in total lipids was between 16.5% (glycerol-based medium in the dark; biomass concentration = 4.2 ± 1.1 g L−1) and 42.6% (glucose-based medium under light; biomass concentration = 3.3 ± 0.1 g L−1), decreasing to 3.8% and 6.1%, respectively, after day 4. In repeated-batch cultures, the total lipids in the biomass increased after glucose or glycerol was fed alone, whereas the total carotenoids (168 ± 7 μg g−1 dry weight (DW)) and phospholipids in the biomass increased after feeding with yeast extract. The biomass with the highest content of phospholipids (28.7 ± 4.3 mg g−1 DW) was obtained using a feed medium formulated with glycerol, yeast extract and ascorbic acid. Glycerol was the best carbon source for the production of a biomass enriched with total lipids (467 ± 45 mg g−1 DW). The composition of carotenoids depended strongly on the composition of the feed. Repeated-batch cultures fed with yeast extract contained canthaxanthin as the main carotenoid, whereas in the cultures fed only with glucose, the biomass contained mainly β-carotene.

Featured Application: Marine biomass of Rhodotorula could be used as an alternative source of PUFAs and carotenoids for human and animal nutrition, using raw glycerol for their culture. Due to the overexploitation of industrial fisheries, as the principal source of fish oil, as well as the increasing replacement of synthetic pigments for animal nutrition, we need to find sustainable sources for these essential nutrient productions. Marine Rhodotorula strains NCYC4007 and NCYC1146 were used to determine the biosynthesis of docosahexaenoic acid (DHA) and carotenoids by biotransforming raw glycerol, a waste product of biodiesel. To evaluate the presence of inhibitory substances in raw glycerol, both strains were also grown in the presence of analytical grade glycerol and glucose as the main carbon source separately. With raw glycerol, NCYC4007 showed a significant correlation between DHA production and intracellular phosphorous concentrations. NCYC1146, a new Rhodotorula strain genetically described in this work, can produce canthaxanthin but only when glycerol is used as a main carbon source. Then, NCYC4007 could synthesize DHA as a phospholipid, and the production of canthaxanthin depends on the kind of carbon source used by NCYC1146. Finally, malate dehydrogenase activity and glucose production can be used as a proxy of the metabolisms in these marine Rhodotorula. This is the first evidence that marine Rhodotorula are capable of synthesizing DHA and canthaxanthin using an alternative and low-cost source of carbon to potentially scale their sustainable production for animal nutrition. [ABSTRACT FROM AUTHOR]

Canthaxanthin is a colourant widely used in medicine, food and cosmetics, which is closely related to human eye dysfunction. The EU determines that the daily acceptable intake of canthaxanthin (ADI) is 0.03 mg canthaxanthin per kg body weight. In order to protect people's diet health and avoid the occurrence of food safety accidents, this paper measured the content of canthaxanthin in 114 egg samples sourced from different regions of China using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The dietary exposure assessment method was used to evaluate the dietary risk to Chinese consumers. Results showed that the content of canthaxanthin varies significantly across regions of origin, with eggs produced in Beijing having a lower amount than those from other regions. The average dietary exposure of children (2–10 years old) was 0.242 ~ 0.653 μg/(kg bw∙d), and the dietary exposure of 95/97.5/99 percentile was 0.246 ~ 1.779 μg/(kg bw∙d). The maximum exposure was 3.089 μg/(kg bw∙d), and its risk quotient was 0.103 (<1), which was an acceptable risk. For the teenager group (11–18 years old), the average dietary exposure was 0.141 ~ 0.247 μg/(kg bw∙d), and the dietary exposure at the 95/97.5/99 percentile was 0.143 ~ 0.671 μg/(kg bw∙d), presenting an acceptable risk. For adults, the dietary risk of eating eggs with canthaxanthin is the lowest among the three age groups. [ABSTRACT FROM AUTHOR]

Currently, there is a dearth of in-depth analysis and research on the impact of canthaxanthin on the production performance, egg quality, physical characteristics, and offspring health of laying hens. Furthermore, the metabolic mechanism of cantharidin in the body remains unclear. Therefore, to solve the above issues in detail, our study was conducted with a control group (C group), a low-dose canthaxanthin group (L group), and a high-dose canthaxanthin group (H group), each fed for a period of 40 days. Production performance was monitored during the experiment, in which L and H groups showed a significant increase in ADFI. Eggs were collected for quality analysis, revealing no significant differences in qualities except for yolk color (YC). The YC of the C group almost did not change, ranging from 6.08 to 6.20; however, the trend in YC change in other groups showed an initial intense increase, followed by a decrease, and eventually reached dynamic equilibrium. By detecting the content of canthaxanthin in the yolk, the YC change trend was found to be correlated with canthaxanthin levels in the yolk. The content of unsaturated fatty acid increased slightly in L and H groups. Following the incubation period, the physical characteristics and blood biochemical indices of chicks were evaluated. It was observed that the shank color of chicks in the L and H groups was significantly higher than that in the C group at birth. However, by the 35th day, there were no significant differences in shank color among the three groups. Further investigation into the metabolic mechanism involving canthaxanthin revealed that the substance underwent incomplete metabolism upon entering the body, resulting in its accumulation as well as metabolic by-product accumulation in the yolk. In summary, this study highlighted the importance of understanding canthaxanthin's role in production performance, egg quality, and offspring health, providing valuable insights for breeders to optimize feeding strategies., Competing Interests: The authors declare no conflicts of interest.

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.)

The objective of this study was to evaluate productive performance and egg quality of Japanese quails (Cortunix japonica) fed with synthetic and natural pigments. The treatments used were: 0.8% paprika extract (Capsicum annuum), 0.8% marigold flower extract, 4% paprika extract and 4% marigold flower extract and 0.045% synthetic pigment (Canthaxanthin) in feed. A total of 240 Japanese quails at 20 weeks of age were distributed in a completely randomized experimental design with five treatments and six replicates, with eight quails per experimental unit (30 experimental units). There was no difference (p > 0.05) for the evaluated parameters, except for yolk color which showed significant difference (p < 0.05) between the treatments used. The inclusion of 0.8% natural pigments in diet of Japanese quails can be used to substitute canthaxathin because it is effective on improving yolk color without affect performance and the quails egg quality.

Considering the importance of microalgae as a promising feedstock for the production of both low- and high-value products, such as lipids and pigments, it is desirable to isolate strains which simultaneously accumulate these two types of products and grow in various conditions in order to widen their biotechnological applicability. A novel freshwater strain from the genus Coelastrella was isolated in Belgium. Compared to other Coelastrella species, the isolate presented rapid growth in phototrophy, dividing 3.5 times per day at a light intensity of 400 µmol·m−2·s−1 and 5% CO2. In addition, nitrogen depletion was associated with the accumulation of astaxanthin, canthaxanthin, and fatty acids, which reached ~30% of dry weight, and a majority of SFAs and MUFAs, which are good precursors for biodiesel. This strain also accumulated astaxanthin and canthaxanthin in heterotrophy. Although the content was very low in this latter condition, it is an interesting feature considering the biotechnological potential of the microalgal heterotrophic growth. Thus, due to its rapid growth in the light, its carotenogenesis, and its fatty acids characteristics, the newly identified Coelastrella strain could be considered as a potential candidate for biorefinery purposes of both low- and high-values products.

In the present study, canthaxanthin was produced by biofermentation from Dietzia natronolimnaea HS-1 (D. natronolimnaea) and was loaded in phospholipid vesicles prepared with natural component using an easy and low dissipative method. Indeed, glycerosomes, hyalurosomes, and glycerohyalurosomes were prepared by direct hydration of both phosphatidylcholine and the biotechnological canthaxanthin, avoiding the use of organic solvents. Vesicles were sized from 63 nm to 87 nm and highly negatively charged. They entrapped a high number of the biomolecules and were stable on storage. Canthaxanthin-loaded vesicles incubated with fibroblasts did not affect their viability, proving to be highly biocompatible and capable of inhibiting the death of fibroblasts stressed with hydrogen peroxide. They reduced the nitric oxide expression in macrophages treated with lipopolysaccharides. Moreover, they favoured the cell migration in an in vitro lesion model. Results confirmed the health-promoting potential of canthaxanthin in skin cells, which is potentiated by its suitable loading in phospholipid vesicles, thus suggesting the possible use of these natural bioformulations in both skin protection and regeneration, thanks to the potent antioxidant, anti-inflammatory and antiageing effects of canthaxanthin.

Copyright of Journal of Animal & Poultry Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Transmembrane 16A (TMEM16A), also known as anoctamin 1, is the molecular basis of the calcium‐activated chloride channels. TMEM16A is present in interstitial cells of Cajal, which are the pacemaker cells that control smooth muscle contraction. TMEM16A is implicated in gastrointestinal disorders. Activation of TMEM16A is believed to promote the gastrointestinal muscle contraction. Here, we report a highly efficient, nontoxic, and selective activator of TMEM16A, canthaxanthin (CX). The study using molecular docking and site‐directed mutation revealed that CX‐specific binging site in TMEM16A is K769. CX was also found to promote the contraction of smooth muscle cells in gastrointestinal tract through activation of TMEM16A channels, which provides an excellent basis for development of CX as a chemical tool and potential therapeutic for gastrointestinal dysfunction. [ABSTRACT FROM AUTHOR]

Over the past decades, nutraceuticals have attracted considerable interest because of their potential nutritional, safety and therapeutic effects. Carotenoid molecules are potent nutraceuticals with an attractive colour and have been shown to play crucial roles in the immune system and susceptibility of organisms to certain diseases. Reactive oxygen species (ROS) are considered to be a major threat to cellular components and lead to protein oxidation, lipid peroxidation and DNA damage. In the present study, canthaxanthin (CX), an orange-red keto-carotenoid, was extracted from Dietzia maris NITD. Carbonyl content measurement showed that the presence of CX can prevent protein oxidation in D. maris NITD. The inhibition of protein oxidation in vitro revealed a high correlation coefficient of the extracted CX with positive controls. Both the linoleic acid model (IC50 = 932.48 µg/ml) and the goat liver model experiments showed that CX can also inhibit lipid peroxidation in vitro. CX from D. maris NITD was also proved to be effective in maintaining the observable intactness of a model DNA (pBR322). The present study indicated that bacterial CX can be a useful bioactive compound to prevent oxidative damage incurred by cellular macromolecules in terms of pharmaceutical and nutraceutical aspects. [ABSTRACT FROM AUTHOR]

In this study, a novel route for the total synthesis of canthaxanthin is described. The synthesis is firstly based on an epoxidation of α-ionone with metachloroperbenzoic acid to afford the epoxide, followed by conversion of the epoxide to 3-hydroxyl-β-ionone in the presence of sodium methoxide. Next, 3-hydroxyl-C14-aldehyde was obtained by a Darzens condensation with 4-hydroxyl-β-ionone and methyl chloroacetate, which can be converted to 3-hydroxyl-C15-phophonate via a Wittig–Horner condensation with tetraethyl methylenebisphosphonate. Then, a Wittig–Horner condensation with 3-hydroxyl-C15-phosphonate and C10-trienedial resulted in 4,4′-dihydroxyl-β-carotene, followed by an oxidation afforded the target product canthaxanthin. The overall yield of this route is 37% from α-ionone. The synthetic steps are easily operated and are practical for the large-scale production. [ABSTRACT FROM AUTHOR]

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. [Display omitted] • Low phase transition temperature increases xanthophyll storage in liposomes. • Liposome-to-protein carotenoid transfer is efficient with PG or unsaturated PC lipids. • Liposome-to-protein transfer is much faster for canthaxanthin than for echinenone. [ABSTRACT FROM AUTHOR]

Abstract. In this study the rate of accumulation of both main pigments in Salmonidae - astaxanthin (AX) and canthaxanthin (CX) in different muscle tissues of Rainbow trout (Oncorhynchus mykiss W.) and their distribution in flesh and heart was researched. Experimental fish were reared 100 days in two tanks as two -1 -1 parallel experimental groups and fed with market feed, containing 40 mg.kg AX and 25 mg.kg CX. The diet was according to the manufacturer's recommendations, which are consistent with fish size and water temperature. The accumulated pigment quantities in the muscle tissues, were measured every twenty days by high performance liquid chromatography with photodiode array detection after selective xanthophyll extraction. The highest rates of AX th th -1 and CX deposition were recorded on the 60 and 80 day. The average contents of AX and CX were at the end of the trial 1.943 ± 0.167 mg.kg and 0.807 ± -1 -1 -1 0.021 mg.kg in skeletal muscle and 0.683 ±0.055mg.kg and 0.280 ±0.017 mg.kg in cardio muscle, respectively.

Background: The number of older people in the world is increasing year by year; studies have shown that more than 90% of cardiovascular disease occurs in the older people population, indicating that aging is one of the major risks involved in the development of cardiovascular disease. Therefore, retarding the development of cardiac aging is an important strategy to prevent aging-related cardiovascular diseases., Methods: In the current study, we examined the anti-cardiovascular aging potential of canthaxanthin in vitro and in vivo experiments. For this, a model of cardiomyocyte senescence induced by D-galactose was established, which was used to investigate the canthaxanthin's effect on cardiac premature aging., Results: We found that canthaxanthin obviously mitigated the cardiomyocyte senescence in vitro . Further mechanistic studies revealed that canthaxanthin seems to alleviate cardiomyocyte senescence by regulating the autophagy process. Furthermore, the effects of canthaxanthin on cardiovascular senescence were further evaluated. We also observed that canthaxanthin mitigated cardiac aging and fibrosis in the aged mice model., Conclusions: To sum up, the current work showed that canthaxanthin could obviously alleviate cardiac premature aging, indicating that canthaxanthin could be used as a biologically active molecule for the treatment of cardiac aging and fibrosis., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s). Published by IMR Press.)

The increased interest in sequencing cyanobacterial genomes has allowed the identification of new homologs to both the N-terminal domain (NTD) and C-terminal domain (CTD) of the Orange Carotenoid Protein (OCP). The N-terminal domain homologs are known as Helical Carotenoid Proteins (HCPs). Although some of these paralogs have been reported to act as singlet oxygen quenchers, their distinct functional roles remain unclear. One of these paralogs (HCP2) exclusively binds canthaxanthin (CAN) and its crystal structure has been recently characterized. Its absorption spectrum is significantly red-shifted, in comparison to the protein in solution, due to a dimerization where the two carotenoids are closely placed, favoring an electronic coupling interaction. Both the crystal and solution spectra are red-shifted by more than 50 nm when compared to canthaxanthin in solution. Using molecular dynamics (MD) and quantum mechanical/molecular mechanical (QM/MM) studies of HCP2, we aim to simulate these shifts as well as obtain insight into the environmental and coupling effects of carotenoid–protein interactions.

Today's global problems and challenges have given rise to a new field of interest – bioeconomics. It is strongly related to phycoprospecting, or searching for specific algal strains of commercial importance. There has been growing interest in the small algal class Eustigmatophyceae in recent years. These microscopic stramenopilic algae, which have all the advantages of microalgal cultivation, have proved to be promising commercial sources of valuable compounds (e.g. carotenoids, unsaturated fatty acids, amino acids) in aquaculture, agriculture, biofuels production, medicine, pharmaceutics, cosmetics, wastewater treatment, environmental control, etc. The present review shows the main genera and strains of commercial importance, outlines their main fields of application and some gaps in our knowledge in this aspect. Today, the great promising bioeconomical potential of these algae has generally been recognized, but in the present state of its infancy, it is far from being fully exploited. [ABSTRACT FROM AUTHOR]

Farmed trout are commonly fed carotenoid-enriched diets during the finishing period to acquire typical red-to-pink flesh color in salmonid muscle. The aim of this study was to examine the effects of two xanthophylls, astaxanthin (Ax) or canthaxanthin (Cx), administered individually or in combination, on oxidative stress biomarkers in kidney and liver of rainbow trout. Specimens were fed Ax (75 mg/kg) or Cx (25 mg/kg) individually or in combination in the diets for 8 weeks. Changes in concentration of oxidative stress biomarkers, including total glutathione, superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione S-transferase, were recorded in Ax- and Cx-dosed trout. These two carotenoids, predominantly Cx, initiated enzymatic responses in rainbow trout. It is noteworthy that lipid peroxidation processes were not apparent in all Ax or Cx-dosed trout. Further, both combined xanthophylls did not exert significant synergistic effects in liver and kidney. Biomarker responses were generally altered in both tissues through the 4 and 8 weeks suggesting that different time-dependent mechanisms led to enhanced antioxidant defense in Ax and/or Cx-fed trout. Data demonstrated that these two xanthophylls did not exert detrimental effects on rainbow trout. [ABSTRACT FROM AUTHOR]

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The cyanobacterium Synechocystis sp. PCC 6803 is a model species commonly employed for biotechnological applications. It is naturally able to accumulate zeaxanthin (Zea) and echinenone (Ech), but not astaxanthin (Asx), which is the highest value carotenoid produced by microalgae, with a wide range of applications in pharmaceutical, cosmetics, food and feed industries. With the aim of finding an alternative and sustainable biological source for the production of Asx and other valuable hydroxylated and ketolated intermediates, the carotenoid biosynthetic pathway of Synechocystis sp. PCC 6803 has been engineered by introducing the 4,4′ β‐carotene oxygenase (CrtW) and 3,3′ β‐carotene hydroxylase (CrtZ) genes from Brevundimonas sp. SD‐212 under the control of a temperature‐inducible promoter. The expression of exogenous CrtZ led to an increased accumulation of Zea at the expense of Ech, while the expression of exogenous CrtW promoted the production of non‐endogenous canthaxanthin and an increase in the Ech content with a concomitant strong reduction of β‐carotene (β‐car). When both Brevundimonas sp. SD‐212 genes were coexpressed, significant amounts of non‐endogenous Asx were obtained accompanied by a strong decrease in β‐car content. Asx accumulation was higher (approximately 50% of total carotenoids) when CrtZ was cloned upstream of CrtW, but still significant (approximately 30%) when the position of genes was inverted. Therefore, the engineered strains constitute a useful tool for investigating the ketocarotenoid biosynthetic pathway in cyanobacteria and an excellent starting point for further optimisation and industrial exploitation of these organisms for the production of added‐value compounds. [ABSTRACT FROM AUTHOR]

The remarkable drought-resistance of the terrestrial cyanobacterium Nostoc flagelliforme (N. flagelliforme) has attracted attention for many years. In this study, we purified a group of red proteins that accumulate in dried field samples of N. flagelliforme. These red proteins contain canthaxanthin as the bound chromophore. Native-PAGE analysis revealed that the purified red proteins resolved into six visible red bands and were composed of four helical carotenoid proteins (HCPs), HCP1, HCP2, HCP3, and HCP6 (homologs to the N-terminal domain of the orange carotenoid protein (OCP)). Seven genes encode homologs of the OCP in the genome of N. flagelliforme: two full-length ocp genes (ocpx1 and ocpx2), four N-terminal domain hcp genes (hcp1, hcp2, hcp3, and hcp6), and one C-terminal domain ccp gene. The expression levels of hcp1, hcp2, and hcp6 were highly dependent on the water status of field N. flagelliforme samples, being downregulated during rehydration and upregulated during subsequent dehydration. Transcripts of ocpx2 were dominant in the dried field samples, which we confirmed by detecting the presence of OCPx2-derived peptides in the purified red proteins. The results shed light on the relationship between carotenoid-binding proteins and the desiccation resistance of terrestrial cyanobacteria, and the physiological functions of carotenoid-binding protein complexes in relation to desiccation are discussed. [ABSTRACT FROM AUTHOR]

Highlights • Astaxanthin biosynthetic genes bkt and crtR-B were transformed into 'Brookfield Gala' apple. • Novel ketocarotenoids including astaxanthin and canthaxanthin were synthesized and accumulated in transgenic apple plants. • Transgenic plants with pink color have hither antioxidant activity and stronger photooxidation resistance compared to wide-type lines. Abstract Apples may suffer sunburn during growing season because of photooxidation damage. Astaxanthin have a stronger antioxidant activity against photooxidation compared to its precursors zeaxanthin and β-carotene. Here, we transferred β-carotene ketolase (bkt) and β-carotene hydroxylase (crtR-B), two genes encoding key enzymes for astaxanthin biosynthesis, into "Brookfield Gala" apple plants using pCAMBIA1302- bkt - crtR - B via transformation mediated by Agrobacterium tumefaciens EHA105. We aimed to confer a stronger antioxidant ability against sunburn to apple plants by regulating metabolic pathways of carotenoids. RT-PCR and qPCR analysis confirmed that bkt and crtR-B genes were expressed simultaneously in transgenic plants. Southern blotting analysis confirmed that the transgene was stably integrated and determined transgene copy number. Transgenic plants synthesized novel ketocarotenoids, resulting in an accumulation of astaxanthin up to 12.06 μg/g and of canthaxanthin up to 6.38 μg/g per leaf fresh weight. The light antioxidant ability of transgenic plantlets was stronger than that of non-transgenic ones in high light conditions. We speculate that the transgenic apples accumulating astaxanthin are resistant to photooxidation and can therefore prevent sunburn. [ABSTRACT FROM AUTHOR]

Abstract 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. [ABSTRACT FROM AUTHOR]

Due to the overexploitation of industrial fisheries, as the principal source of fish oil, as well as the increasing replacement of synthetic pigments for animal nutrition, we need to find sustainable sources for these essential nutrient productions. Marine Rhodotorula strains NCYC4007 and NCYC1146 were used to determine the biosynthesis of docosahexaenoic acid (DHA) and carotenoids by biotransforming raw glycerol, a waste product of biodiesel. To evaluate the presence of inhibitory substances in raw glycerol, both strains were also grown in the presence of analytical grade glycerol and glucose as the main carbon source separately. With raw glycerol, NCYC4007 showed a significant correlation between DHA production and intracellular phosphorous concentrations. NCYC1146, a new Rhodotorula strain genetically described in this work, can produce canthaxanthin but only when glycerol is used as a main carbon source. Then, NCYC4007 could synthesize DHA as a phospholipid, and the production of canthaxanthin depends on the kind of carbon source used by NCYC1146. Finally, malate dehydrogenase activity and glucose production can be used as a proxy of the metabolisms in these marine Rhodotorula. This is the first evidence that marine Rhodotorula are capable of synthesizing DHA and canthaxanthin using an alternative and low-cost source of carbon to potentially scale their sustainable production for animal nutrition.

In this study, the pH-shifting method was used for the encapsulation of microbial canthaxanthin with soy protein hydrolysates to increase its antioxidant activity. Enzymatic hydrolysis improved the functional and structural properties of soy protein hydrolysates in comparison to native ones. Reducing power and radical quenching activity of hydrolysates were raised respectively from 14.6 and 0.05 to 92.9 and 0.19 and their bioactive loading properties were significantly increased more than five times. Encapsulation parameters, structural attributes, and antioxidant activity were also studied after complexation. Fourier transform infrared spectroscopy findings indicated the formation of hydrogen bonds between canthaxanthin and hydrolysates. The crystalline nature of canthaxanthin was changed to amorphous, according to the X-ray diffraction assay. Reducing power and radical quenching activity increased (respectively 2.3-fold and 1.5-fold). The results showed the positive effects of enzymatic hydrolysis of soy protein and the pH-driven method of encapsulation on improvement in the antioxidant activity of canthaxanthin. • Canthaxanthin was produced by Dietzia natronolimnaea HS-1. • Soy protein hydrolyzed using trypsin which improved its bioactive-loading capacity. • Canthaxanthin encapsulated with soy protein hydrolysates using pH-driven method. • pH-driven method increased dissolved canthaxanthin and its availability. • Results showed higher antioxidant activity after encapsulation. [ABSTRACT FROM AUTHOR]

Carotenoids are well-known bioactive compounds and high-value nutritional molecules. Chromochloris zofingiensis , a unicellular green alga, is a promising source of commercial carotenoids owing to its robust growth, easy cultivation, and facile scale-up. However, this microalga has a very rigid three-layered cell wall that hinders extraction. Meanwhile, traditional extraction methods are complicated and cause serious pollution. To address these issues, a eutectic solvent (ES) was identified from 15 candidates for the ultrasonic-assisted extraction of canthaxanthin from C. zofingiensis for the first time. Remarkably, this hydrophobic ES comprising octanoic and decanoic acid displayed novel dual functions of breaking the cell wall and carotenoid extraction. Under the optimised extraction conditions obtained using a response surface methodology (ultrasound at 50 ℃ for 49 min, octanoic acid-to-decanoic acid molar ratio of 2.3:1, and solid-to-solvent ratio of 66.2 mg/mL), the maximum yield of canthaxanthin (60.5 μg/mL) was equal or superior to that using traditional organic extractant after grinding to break the cell wall. Furthermore, only the ES was employed as the extraction solvent, and the canthaxanthin content obtained by pre-grinding under the same condition (70.4 μg/mL) was much higher than that of grinding and extraction with ethanol (62.2 μg/mL). Possible mechanisms of cell wall breakage and component extraction were investigated based on extraction kinetic analysis, molecular dynamics simulation, and scanning electron microscopy observation. This ES is non-volatile and environmentally friendly, making it a simple, sustainable, and effective alternative extractant for carotenoids in microalga. There is considerable potential for its industrial-scale development and applications in various fields such as food, medicine, and cosmetics. • 15 eutectic solvents were tested for extracting canthaxanthin in microalgae. • The system consisting of octanoic and decanoic acids showed the best performance. • Extraction parameters were optimised using response surface methodology. • This solvent both breaks the microalgal cell wall and extracts carotenoid. • The possible extraction mechanism was investigated and discussed for the first time. [ABSTRACT FROM AUTHOR]

Carotenoids, one of the most common types of natural pigments, can influence the colors of living organisms. More than 750 kinds of carotenoids have been identified. Generally, carotenoids occur in organisms at low levels. However, the total amount of carotenoids in nature has been estimated to be more than 100 million tons. There are two major types of carotenoids: carotene (solely hydrocarbons that contain no oxygen) and xanthophyll (contains oxygen). Carotenoids are lipid-soluble pigments with conjugated double bonds that exhibit robust antioxidant activity. Many carotenoids, particularly astaxanthin (ASX), are known to improve the antioxidative state and immune system, resulting in providing disease resistance, growth performance, survival, and improved egg quality in farmed fish without exhibiting any cytotoxicity or side effects. ASX cooperatively and synergistically interacts with other antioxidants such as α-tocopherol, ascorbic acid, and glutathione located in the lipophilic hydrophobic compartments of fish tissue. Moreover, ASX can modulate gene expression accompanying alterations in signal transduction by regulating reactive oxygen species (ROS) production. Hence, carotenoids could be used as chemotherapeutic supplements for farmed fish. Carotenoids are regarded as ecologically friendly functional feed additives in the aquaculture industry.

Carotenoids are a class of pigments with a biological role in light capture and antioxidant activities. High value ketocarotenoids, such as astaxanthin and canthaxanthin, are highly appealing for applications in human nutraceutical, cosmetic, and animal feed industries due to their color- and health-related properties. In this review, recent advances in metabolic engineering and synthetic biology towards the production of ketocarotenoids, in particular the red-orange canthaxanthin, are highlighted. Also reviewed and discussed are the properties of canthaxanthin, its natural producers, and various strategies for its chemical synthesis. We review the de novo synthesis of canthaxanthin and the functional β-carotene ketolase enzyme across organisms, supported by a protein-sequence-based phylogenetic analysis. Various possible modifications of the carotenoid biosynthesis pathway and the present sustainable cost-effective alternative platforms for ketocarotenoids biosynthesis are also discussed.

This article reviews the excited-state quenching, pro-vitamin A activity and anticarcinogenicity of carotenes and xanthophylls in relation to their chemical structures. Excited-state quenching improved with the length of the conjugated chain structure. Pro-vitamin A activity was dependent on the presence of at least one beta-ionyl ring structure. The effectiveness of carotenoids as antioxidants depended on their ability to trap peroxyl radicals with production of resonance-stabilized carotenyl radicals. The products identified from oxidations of carotenes and xanthophylls with molecular oxygen and other oxidizing agents are presented. The free radical-mediated mechanisms that have been proposed to account for the different classes of products are reviewed.

The aim of this study was to evaluate the use of an additive canthaxanthin based and annatto extract (Bixa orellana L.) in diets of laying hens and its effect on the color of the yolk and the egg shelf life. Position 864 hens 34 to 45 weeks old, distributed in a completely randomized design with six replicates per treatment were used. Treatments were T0 (control diet), T1 (T0 + 30 g of canthaxanthin and annatto extract) and T2 (T0 + 60 g of canthaxanthin and annatto extract). The results were 88.6; 91.9 and 90.8% for laying percentage; 60.5; 61.6 and 61.5 g for egg weight; 53.6; 56.4 and 55.7 g for egg mass. The yolk color temperature 7 °C for Roche scale was 6, 9 and 12 and colorimetric Minolta was to "L" of 42.10; 40.24 and 39.65; for "a" of 0.07; 3.68 and 6.44 and for "b" of 19.35; 18.36 and 18.18. Shelf life at room temperature 7 °C was 81, 86 and 90 UH. Lipid peroxidation was 0.10; 0.07 and 0.05 μmol MDA.g-1 yolk; for T0, T1 and T2 respectively. In all variables indicated statistically significant differences between treatments (p < 0.05). Food consumption was 103.9; 109.2 and 107.5 g and feed conversion of 1.94; 1.93 and 1.92. It is concluded that the addition of canthaxanthin and annatto extract to 30 and 60 g t-1 feed than the control, improved performance parameters, yolk color and egg shelf life.