Zeaxanthin-Rich Extract from Superfood Lycium barbarum Selectively Modulates the Cellular Adhesion and MAPK Signaling in Melanoma versus Normal Skin Cells In Vitro.

The concern for implementing bioactive nutraceuticals in antioxidant-related therapies is of great importance for skin homeostasis in benign or malignant diseases. In order to elucidate some novel insights of Lycium barbarum (Goji berry) activity on skin cells, the present study focused on its active compound zeaxanthin. By targeting the stemness markers CD44 and CD105, with deep implications in skin oxidative stress mechanisms, we revealed, for the first time, selectivity in zeaxanthin activity. When applied in vitro on BJ human fibroblast cell line versus the A375 malignant melanoma cells, despite the moderate cytotoxicity, the zeaxanthin-rich extracts 1 and 2 were able to downregulate significantly the CD44 and CD105 membrane expression and extracellular secretion in A375, and to upregulate them in BJ cells. At mechanistic level, the present study is the first to demonstrate that the zeaxanthin-rich Goji extracts are able to influence selectively the mitogen-activated protein kinases (MAPK): ERK, JNK and p38 in normal BJ versus tumor-derived A375 skin cells. These results point out towards the applications of zeaxanthin from L. barbarum as a cytoprotective agent in normal skin and raises questions about its use as an antitumor prodrug alone or in combination with standard therapy.

Recovery and recycling of solvent of counter-current chromatography: The sample of isolation of zeaxanthin in the Lycium barbarum L. fruits.

An efficient method of recovering and recycling solvent for counter-current chromatography was established by which zeaxanthin was separated from Lycium barbarum L. fruits. A column with activated carbon combined with high performance counter-current chromatography formed the recovering and recycling solvent system. Using the solvent system of n-hexane-ethyl acetate-ethanol-water (8:2:7:3, v/v) from the references, five injections were performed with an almost unchanged purity of zeaxanthin (80.9, 81.2, 81.5, 81.3, and 80.2% respectively) in counter-current chromatography separation. Meanwhile, the mobile phase reduced by half than conventional counter-current chromatography. By this present method, an effective improvement of counter-current chromatography solvent utilization was achieved.

Optimization of Ultrasonic-Assisted Extraction and Purification of Zeaxanthin and Lutein in Corn Gluten Meal.

Zeaxanthin and lutein have a wide range of pharmacological applications. In this study, we conducted systematic experimental research to optimize antioxidant extraction based on detection, extraction, process amplification, and purification. An ultrasonic-assisted method was used to extract zeaxanthin and lutein with high efficiency from corn gluten meal. Firstly, the effects of solid-liquid ratio, extraction temperature, and ultrasonic extraction time on the extraction of zeaxanthin were investigated in single-factor experiments. The optimization extraction parameters of zeaxanthin and lutein with ethanol solvent were obtained using the response surface methodology (RSM) as follows: liquid-solid ratio of 7.9:1, extraction temperature of 56 °C, and extraction time of 45 min. The total content of zeaxanthin and lutein was 0.501%. The optimum extraction experimental parameters were verified by process amplification, and we confirmed that the parameters of the extraction process optimized using the RSM design are reliable and precise. Zeaxanthin and lutein from crude extract of corn gluten were separated and purified using silica gel column chromatography with the purity of zeaxanthin increasing from 0.28% to 31.5% (about 110 times) and lutein from 0.25% to 16.3% (about 65 times), which could be used for large-scale industrial production of carotenoids.

Zeaxanthin Isolated from Dunaliella salina Microalgae Ameliorates Age Associated Cardiac Dysfunction in Rats through Stimulation of Retinoid Receptors.

Retinoids are essential during early cardiovascular morphogenesis. However, recent studies showed their important role in cardiac remodeling in rats with hypertension and following myocardial infarction. The present study aimed to investigate the effect of zeaxanthin heneicosylate (ZH); a carotenoid ester isolated from Dunaliella salina microalgae, on cardiac dysfunction ensuing d-galactose injection in rats. Rats injected with d-GAL (200 mg/kg; I.P) for 8 weeks were orally treated with ZH (250 µg/kg) for 28 consecutive days. Results showed that d-GAL injection caused dramatic electrocardiographic changes as well as marked elevation in serum levels of homocysteine, creatinine kinase isoenzyme and lactate dehydrogenase. A reduction in the cardiac contents of glucose transporter-4 and superoxide dismutase along with the elevation of inducible nitric oxide synthetase and interleukin-6 was also noticed. Oral administration of ZH significantly improved the above mentioned cardiac aging manifestations; this was further emphasized through histopathological examinations. The effect of ZH is mediated through the interaction with retinoid receptor alpha (RAR-α) as evidenced through a significant elevation of RAR-α expression in cardiac tissue following the lead of an in silico molecular docking study. In conclusion, zeaxanthin heneicosylate isolated from D. salina ameliorated age-associated cardiac dysfunction in rats through the activation of retinoid receptors.

Marigold carotenoids: Much more than lutein esters.

Carotenoids constitute a large group of lipophilic pigments whose health-promoting benefits have been widely recognized. Hydroxy-containing carotenoids can be found in both free form or esterified with fatty acids in several plant matrices, but the native carotenoid profile is overall poorly explored due to the difficulty of analyzing carotenoid esters. One of the main natural sources of carotenoids is the marigold flower, which has been extensively used by the industry for the production of food colorants or supplements, both often manufactured with no saponification process. Although lutein esters are well established as the major compounds naturally found in marigold petals and their products, carotenoid esters other than the lutein ones have not been extensively examined. We carried out a comprehensive identification of carotenoids and carotenoid esters from marigold petals by LC-DAD-(APCI+)MS/MS. Whereas 18 carotenoids were identified in the saponified extract, 56 were identified when no saponification procedure was carried out: 6 free carotenoids, 20 monoesters and 30 diesters. This is the first time that esters of zeaxanthin, violaxanthin, auroxanthin, zeinoxanthin and ß-cryptoxanthin are identified in marigold. The structural information obtained through characteristic fragmentation patterns and diagnostic fragments in MS and MS/MS spectra (APCI+) sustained the differentiation between carotenoid esters with similar characteristics. Therefore, the separation of carotenoids by reversed-phase liquid chromatography using C30 columns in combination with DAD and APCI-MS/MS detection allowed high sensitivity and selectivity for carotenoid ester analysis.

Effect of refining on bioactive composition and oxidative stability of hazelnut oil.

In this study, the effect of refining process on the content of phytochemicals, antioxidant capacity and oxidative stability of hazelnut oil was investigated. The oil samples were taken at the consecutive steps of hazelnut refining process and analyzed for some compositional properties along with the antioxidant capacity and oxidative stability. The results have shown that, carotenoid content of the hazelnut oil was decreased during the refining process. The main carotenoids of hazelnut oil were found to be lutein and zeaxanthin and these compounds were lost completely during bleaching step of the refining. On the other hand, phenolic compounds and tocopherols were also partly removed from hazelnut oil to a degree. Loses in antioxidant compounds caused a clear decrease in antioxidant capacity measured in either the oils or polar extract of oils. Oxidative stability of the oil samples was measured by Rancimat method and it was found that neutralization caused an increase in oxidative stability compared to the crude oil. However, deodorization step caused a slight decrease in oxidative stability probably as a result of partial removal of tocopherols at this stage.

Screening, Isolation, and Identification of Zeaxanthin-Producing Bacteria.

Zeaxanthin is a yellow xanthophyll, dihydroxy-carotenoid, that is naturally found in some of the green, orange, and yellow vegetables and fruits and has a powerful antioxidant activity. Epidemiological evidences suggest that increasing the consumption of zeaxanthin in the diet is associated with a lower risk of age-related macular degeneration (ARMD) and cataracts, two of the leading causes of blindness in the world. Zeaxanthin is a promising nutraceutical/colorant with many applications in feed, food, and pharmaceutical industries. Currently, the commercial production of zeaxanthin is dependent on synthetic routes with limitation in production from biological sources. However, the biotechnological production of natural zeaxanthin is favored due to its safety, potential large-scale production and consumers' preference for natural additives. In this chapter, we describe a rapid screening method based on 16S rRNA gene sequencing and effective HPLC with diode array detector/MS methods for the isolation and identification of zeaxanthin-producing bacteria and their carotenoid analysis.

Extraction and Analysis of Carotenes and Xanthophylls Produced by Xanthophyllomyces dendrorhous.

Xanthophyllomyces dendrorhous, a heterobasidiomycetous yeast that represents the teleomorphic state of Phaffia rhodozyma, is used as a natural source of several carotenoids, such as the xanthophyll astaxanthin. Here, we describe the culture procedure for the production of carotenoids in X. dendrorhous and a simple and rapid analytical method for the optimized extraction and HPLC determination of intracellular ß-carotene, astaxanthin, canthaxanthin, and zeaxanthin.

Virgin Olive Oil Enriched with Lutein-Zeaxanthin from Spinacia oleracea.

The aim of this work consists of developing a technological process for elaborating a virgin olive oil enriched in lutein-zeaxanthin extracted from spinach, studying different parameters like temperature, time of extraction and different ratios (spinach-oil). It was observed that the amount of carotenoids extracted increased up to a maximum after 24 hours and decreased as the maceration time progressed up to 60 hours, resulting of biological degradation. It was also observed that as more spinach we added, as more lutein-zeaxanthin in the enriched virgin olive oil was obtained. The best results were obtained after 24 hours by using a 75:25 ratio at 30°C. Values of oxidative stability decreased drastically, as well as other parameters such as acidity; peroxides index and Ks were modified when the enriched virgin olive oil was subjected to 45°C for 24 hours of maceration. Thus, the present procedure constitutes a way to achieve an increase in the daily intake of beneficial compounds.

Macular pigment carotenoids in the retina and occipital cortex are related in humans.

OBJECTIVES: Lutein and zeaxanthin are dietary carotenoids that preferentially accumulate in the macular region of the retina. Together with meso-zeaxanthin, a conversion product of lutein in the macula, they form the macular pigment. Lutein is also the predominant carotenoid in human brain tissue and lutein status is associated with cognitive function in adults. The study objective was to evaluate the relationship between retinal and brain lutein and zeaxanthin in humans. METHODS: Donated brain tissue (occipital cortex and hippocampus) and matched retina were obtained from the National Disease Research Interchange, a national human tissue resource center which adheres to strict consent and confidentiality procedures. Decedents were men and women aged >50 years who either had normal cognitive function or Alzheimer's disease. Tissues were analyzed using standard lipid extractions followed by analysis on reverse-phase high performance liquid chromatography (HPLC) and normal-phase HPLC (for meso-zeaxanthin). RESULTS: Macular pigment carotenoids (lutein, meso-zeaxanthin, and zeaxanthin combined) in the retina were significantly related to the combined concentrations of lutein and zeaxanthin in the occipital cortex. When analyzed separately, only retinal lutein (plus meso-zeaxanthin), not zeaxanthin, was significantly related to lutein in the occipital cortex. No correlations were observed with lutein and zeaxanthin in the hippocampus. DISCUSSION: Total macular pigment density measured via non-invasive, psychophysical techniques can be used as a biomarker to ascertain brain lutein and zeaxanthin status in clinical studies.

Accelerated solvent extraction of carotenoids from: Tunisian Kaki (Diospyros kaki L.), peach (Prunus persica L.) and apricot (Prunus armeniaca L.).

Extraction of carotenoids from biological matrices and quantifications remains a difficult task. Accelerated solvent extraction was used as an efficient extraction process for carotenoids extraction from three fruits cultivated in Tunisia: kaki (Diospyros kaki L.), peach (Prunus persica L.) and apricot (Prunus armeniaca L.). Based on a design of experiment (DoE) approach, and using a binary solvent consisting of methanol and tetrahydrofuran, we could identify the best extraction conditions as being 40°C, 20:80 (v:v) methanol/tetrahydrofuran and 5 min of extraction time. Surprisingly and likely due to the high extraction pressure used (103 bars), these conditions appeared to be the best ones both for extracting xanthophylls such as lutein, zeaxanthin or ß-cryptoxanthin and carotenes such as ß-carotene, which present quite different polarities. Twelve surface responses were generated for lutein, zeaxanthin, ß-cryptoxanthin and ß-carotene in kaki, peach and apricot. Further LC-MS analysis allowed comparisons in carotenoids profiles between the fruits.