Health protective effects of carotenoids and their interactions with other biological antioxidants

Halophilic Carotenoids and Breast Cancer: From Salt Marshes to Biomedicine

Breast cancer is the leading cause of death among women worldwide. Over the years, oxidative stress has been linked to the onset and progression of cancer. In addition to the classical histological classification, breast carcinomas are classified into phenotypes according to hormone receptors (estrogen receptor-RE-/progesterone receptor-PR) and growth factor receptor (human epidermal growth factor receptor-HER2) expression. Luminal tumors (ER/PR-positive/HER2-negative) are present in older patients with a better outcome. However, patients with HER2-positive or triple-negative breast cancer (TNBC) (ER/PR/HER2-negative) subtypes still represent highly aggressive behavior, metastasis, poor prognosis, and drug resistance. Therefore, new alternative therapies have become an urgent clinical need. In recent years, anticancer agents based on natural products have been receiving huge interest. In particular, carotenoids are natural compounds present in fruits and vegetables, but algae, bacteria, and archaea also produce them. The antioxidant properties of carotenoids have been studied during the last years due to their potential in preventing and treating multiple diseases, including cancer. Although the effect of carotenoids on breast cancer during in vitro and in vivo studies is promising, clinical trials are still inconclusive. The haloarchaeal carotenoid bacterioruberin holds great promise to the future of biomedicine due to its particular structure, and antioxidant activity. However, much work remains to be performed to draw firm conclusions. This review summarizes the current knowledge on pre-clinical and clinical analysis on the use of carotenoids as chemopreventive and chemotherapeutic agents in breast cancer, highlighting the most recent results regarding the use of bacterioruberin from haloarchaea.

Skin colour, carotenogenesis and chlorophyll degradation mutant alleles: genetic orchestration behind the fruit colour variation in tomato

The genetics underlying the fruit colour variation in tomato is an interesting area of both basic and applied research in plant biology. There are several factors, like phytohormones, environmental signals and epistatic interactions between genes, which modulate the ripe fruit colour in tomato. However, three aspects: genetic regulation of skin pigmentation, carotenoid biosynthesis and ripening-associated chlorophyll degradation in tomato fruits are of pivotal importance. Different genes along with their mutant alleles governing the aforementioned characters have been characterized in detail. Moreover, the interaction of these mutant alleles has been explored, which has paved the way for developing novel tomato genotypes with unique fruit colour and beneficial phytonutrient composition. In this article, we review the genes and the corresponding mutant alleles underlying the variation in tomato skin pigmentation, carotenoid biosynthesis and ripening-associated chlorophyll degradation. The possibility of generating novel fruit colour-variants using different combinations of these mutant alleles is documented. Furthermore, the involvement of some other mutant alleles (like those governing purple fruit colour and high fruit pigmentation), not belonging to the aforementioned three categories, are discussed in brief. The simplified representation of the assembled information in this article should not only help a broad range of readers in their basic understanding of this complex phenomenon but also trigger them for further exploration of the same. The article would be useful for genetic characterization of fruit colour-variants and molecular breeding for fruit colour improvement in tomato using the well-characterized mutant alleles.

The histone variant Sl_H2A.Z regulates carotenoid biosynthesis and gene expression during tomato fruit ripening

The conserved histone variant H2A.Z is essential for transcriptional regulation; defense responses; and various biological processes in plants, such as growth, development, and flowering. However, little is known about how H2A.Z affects the developmental process and ripening of tomato fruits. Here, we utilized the CRISPR/Cas9 gene-editing system to generate a sl_hta9 sl_hta11 double-mutant, designated sl_h2a.z, and found that these two mutations led to a significant reduction in the fresh weight of tomato fruits. Subsequent messenger RNA (mRNA)-seq results showed that dysfunction of Sl_H2A.Z has profound effects on the reprogramming of genome-wide gene expression at different developmental stages of tomato fruits, indicating a ripening-dependent correlation between Sl_H2A.Z and gene expression regulation in tomato fruits. In addition, the expression of three genes, SlPSY1, SlPDS, and SlVDE, encoding the key enzymes in the biosynthesis pathway of carotenoids, was significantly upregulated in the later ripening stages, which was consistent with the increased contents of carotenoids in sl_h2a.z double-mutant fruits. Overall, our study reveals a role of Sl_H2A.Z in the regulation of carotenoids and provides a resource for the study of Sl_H2A.Z-dependent gene expression regulation. Hence, our results provide a link between epigenetic regulation via histone variants and fruit development, suggesting a conceptual framework to understand how histone variants regulate tomato fruit quality.

Preliminary Study on Pasta Samples Characterized in Antioxidant Compounds and Their Biological Activity on Kidney Cells

Pasta is one of the basic foods of the Mediterranean diet and for this reason it was chosen for this study to evaluate its antioxidant properties. Three types of pasta were selected: buckwheat, rye and egg pasta. Qualitative-quantitative characterization analyses were carried out by HPLC-DAD to identify antioxidant compounds. The data showed the presence of carotenoids such as lutein and polyphenols such as indoleacetic acid, (carotenoids from 0.08 to 0.16 mg/100 g, polyphenols from 3.7 to 7.4 mg/100 g). To assess the effect of the detected metabolites, in vitro experimentation was carried out on kidney cells models: HEK-293 and MDCK. Standards of β-carotene, indoleacetic acid and caffeic acid, hydroalcoholic and carotenoid-enriched extracts from samples of pasta were tested in presence of antioxidant agent to determine viability variations. β-carotene and indoleacetic acid standards exerted a protective effect on HEK-293 cells while no effect was detected on MDCK. The concentrations tested are likely in the range of those reached in body after the consumption of a standard pasta meal. Carotenoid-enriched extracts and hydroalcoholic extracts showed different effects, observing rescues for rye pasta hydroalcoholic extract and buckwheat pasta carotenoid-enriched extract, while egg pasta showed milder dose depending effects assuming pro-oxidant behavior at high concentrations. The preliminary results suggest behaviors to be traced back to the whole phytocomplexes respect to single molecules and need further investigations.

Carotenoids from persimmon juice processing

The aim of this study was the use and revalorization of two persimmon by-products A and B generated in the juice production process. The by-product B resulting from a pectinase enzymatic treatment of peels and pulp to optimize juice extraction was especially suitable for recovery of valuable bioactive carotenoids. The extraction solvents and solvent combinations used were: ethanol, acetone, ethanol/acetone (50:50 v/v) and ethanol/acetone/hexane (25:25:50 v/v/v). HPLC-DAD analysis detected and identified a total of nine individual carotenoids namely violaxanthin, neoxanthin, antheraxanthin, lutein, zeaxanthin, β-cryptoxanthin 5,6-epoxide, β-cryptoxanthin, α-carotene, and β-carotene. β-cryptoxanthin and β-carotene represented 49.2% and 13.2% of the total carotenoid content (TCC) in the acetone extract from by-product B. TCC contributed greatly to antioxidant activity of acetone extract derived from this by-product. Pectinase enzymatic treatment of persimmon peels and pulp followed by absolute acetone extraction of carotenoids could be an efficient method to obtain a rich extract in these compounds that could be used as nutraceutical ingredient.

Skin carotenoids status as a potential surrogate marker for cardiovascular disease risk determination in middle-aged and older adults

BACKGROUND AND AIMS

Upon consumption, carotenoids, which may attenuate cardiovascular disease (CVD) risk, diffuse from the blood and accumulate in the skin. This study aimed to assess the associations between dietary, plasma, and skin carotenoids with CVD risk indicators and to examine the mediational role of plasma carotenoids in the relationship between skin carotenoids status (SCS) and CVD risk.

METHODS AND RESULTS

Dietary, plasma, and skin carotenoids were assessed in a cross-sectional study from a community in Singapore (n = 103) aged 50 to 75 y. Multiple linear regression and binary logistics regression models were used to examine the associations between the carotenoids status with classical CVD risk factors and composite CVD risk indicators. After controlling for covariates, SCS and plasma carotenoids were inversely associated with systolic blood pressure (skin: P < 0.001; plasma: P < 0.05) and diastolic blood pressure (skin: P < 0.001; plasma: P < 0.005). Additionally, each increment of 1000 in SCS was associated with an odds ratio of 0.924 (P < 0.01) for metabolic syndrome diagnosis and 0.945 (P < 0.05) for moderate to high CVD risk classification. Associations between SCS and composite CVD risk indicators were null when adjusted for the corresponding plasma carotenoids, indicating complete mediation. Dietary carotenoids, however, showed no relationship with the CVD risk indicators.

CONCLUSION

Carotenoids bioavailability may be important for cardiovascular protection. SCS, driven by the corresponding plasma carotenoids, could be a potential noninvasive surrogate marker for CVD risk determination in middle-aged and older adults.

CLINICAL TRIAL REGISTRATION

NCT03554954, https://clinicaltrials.gov/.

TRIAL REGISTRATION DATE

13 June 2018.

Contribution of Tocols to Food Sensorial Properties, Stability, and Overall Quality

This paper reviews the contribution of tocopherols and tocotrienols (tocols) to food quality as well as their bioactivity and health-promoting properties, which have attracted researchers and food technologists. Tocols are lipophilic phenolic antioxidants encompassing tocopherols that are characterized by a saturated side chain and tocotrienols with an unsaturated isoprenoid side chain. Tocols are natural constituents of several foods like dairy, vegetable oils, nuts, and grains. Their presence in foods, namely, as food additives, helps prevent lipid oxidation, which negatively affects the sensorial quality of foods, and even the nutritional value and safety. Supplementation of animals’ diets with tocopherols has proven its effectiveness in preserving fresh color and flavor of the meat. Although alfa-tocopherol displays much higher vitamin E activity than other tocols, health outcomes have been reported for tocotrienols, thus calling for more studies.

Chili Pepper Carotenoids: Nutraceutical Properties and Mechanisms of Action

Chili pepper is a prominent cultivated horticultural crop that is traditionally used for food seasoning and is applied for the treatment and prevention of multiple diseases. Its beneficial health properties are due to its abundance and variety of bioactive components, such as carotenoids, capsaicinoids, and vitamins. In particular, carotenoids have important nutraceutical properties, and several studies have focused on their potential in the prevention and treatment of human diseases. In this article, we reviewed the state of knowledge of general aspects of chili pepper carotenoids (biosynthesis pathway, types and content in Capsicum spp., and the effects of processing on carotenoid content) and recent findings on the effects of carotenoid nutraceuticals, such as antioxidant, cancer preventive, anti-inflammatory, cardiovascular disorder preventive, and anti-obesity effects.

Properties of Carotenoids in Fish Fitness: A Review

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.

A Mechanistic Review of β-Carotene, Lutein, and Zeaxanthin in Eye Health and Disease

Carotenoids are natural lipid-soluble antioxidants abundantly found as colorful pigments in fruits and vegetables. At least 600 carotenoids occur naturally, although about 20 of them, including β-carotene, α-carotene, lycopene, lutein, zeaxanthin, meso-zeaxanthin, and cryptoxanthin, are detectable in the human blood. They have distinct physiological and pathophysiological functions ranging from fetal development to adult homeostasis. β-carotene is a precursor of vitamin A that essentially functions in many biological processes including vision. The human macula lutea and eye lens are rich in lutein, zeaxanthin, and meso-zeaxanthin, collectively known as macular xanthophylls, which help maintain eye health and prevent ophthalmic diseases. Ocular carotenoids absorb light from the visible region (400-500 nm wavelength), enabling them to protect the retina and lens from potential photochemical damage induced by light exposure. These natural antioxidants also aid in quenching free radicals produced by complex physiological reactions and, consequently, protect the eye from oxidative stress, apoptosis, mitochondrial dysfunction, and inflammation. This review discusses the protective mechanisms of macular xanthophylls in preventing eye diseases such as cataract, age-related macular degeneration, and diabetic retinopathy. Moreover, some preclinical animal studies and some clinical trials are discussed briefly to understand carotenoid safety and efficacy.

Recent Advances in Astaxanthin Micro/Nanoencapsulation to Improve Its Stability and Functionality as a Food Ingredient

Astaxanthin is a carotenoid produced by different organisms and microorganisms such as microalgae, bacteria, yeasts, protists, and plants, and it is also accumulated in aquatic animals such as fish and crustaceans. Astaxanthin and astaxanthin-containing lipid extracts obtained from these sources present an intense red color and a remarkable antioxidant activity, providing great potential to be employed as food ingredients with both technological and bioactive functions. However, their use is hindered by: their instability in the presence of high temperatures, acidic pH, oxygen or light; their low water solubility, bioaccessibility and bioavailability; their intense odor/flavor. The present paper reviews recent advances in the micro/nanoencapsulation of astaxanthin and astaxanthin-containing lipid extracts, developed to improve their stability, bioactivity and technological functionality for use as food ingredients. The use of diverse micro/nanoencapsulation techniques using wall materials of a different nature to improve water solubility and dispersibility in foods, masking undesirable odor and flavor, is firstly discussed, followed by a discussion of the importance of the encapsulation to retard astaxanthin release, protecting it from degradation in the gastrointestinal tract. The nanoencapsulation of astaxanthin to improve its bioaccessibility, bioavailability and bioactivity is further reviewed. Finally, the main limitations and future trends on the topic are discussed.

Quantitative kinetics of intracellular singlet oxygen generation using a fluorescence probe

Singlet oxygen (¹O₂) is a type of reactive oxygen species involved in numerous physiological activities. We previously reported that ¹O₂-specific oxidation products are increased in patients with prediabetes, suggesting that measurement of ¹O₂ may be an important indicator of physiological and pathological conditions. The turnover in the generation and quenching of ¹O₂ is extremely rapid during biological activities owing to it high reactivity and short lifetime in solution. However, the dynamic changes in ¹O₂ generation in living cells have not been fully explored. In this study, we investigated whether the kinetics of ¹O₂ generation can be quantified using a far-red fluorescent probe for mitochondrial ¹O₂, Si-DMA, following addition of the ¹O₂ generator, endoperoxide, to mammalian cells. The kinetics of Si-DMA fluorescence intensity dose-dependently increased following treatment of mammalian living cells with endoperoxide. Alternatively, treatment with ¹O₂ quenchers decreased the fluorescence intensities following endoperoxide treatment. Our results indicate that the kinetics of intracellular ¹O₂ can be readily obtained using Si-DMA and time-lapse imaging, which provides new insights into the mechanism of ¹O₂ generation in mammalian cells and the exploration of ¹O₂ generators and quenchers.

Pro-Oxidant Actions of Carotenoids in Triggering Apoptosis of Cancer Cells: A Review of Emerging Evidence

Carotenoids are well known for their potent antioxidant function in the cellular system. However, in cancer cells with an innately high level of intracellular reactive oxygen species (ROS), carotenoids may act as potent pro-oxidant molecules and trigger ROS-mediated apoptosis. In recent years, the pro-oxidant function of several common dietary carotenoids, including astaxanthin, β-carotene, fucoxanthin, and lycopene, has been investigated for their effective killing effects on various cancer cell lines. Besides, when carotenoids are delivered with ROS-inducing cytotoxic drugs (e.g., anthracyclines), they can minimize the adverse effects of these drugs on normal cells by acting as antioxidants without interfering with their cytotoxic effects on cancer cells as pro-oxidants. These dynamic actions of carotenoids can optimize oxidative stress in normal cells while enhancing oxidative stress in cancer cells. This review discusses possible mechanisms of carotenoid-triggered ROS production in cancer cells, the activation of pro-apoptotic signaling by ROS, and apoptotic cell death. Moreover, synergistic actions of carotenoids with ROS-inducing anti-cancer drugs are discussed, and research gaps are suggested.

Carotenoids and Chlorophylls as Antioxidants

Chlorophylls and carotenoids are natural pigments that are present in our daily diet, especially with the increasing tendency towards more natural and healthy behaviors among consumers. As disturbed antioxidant homeostasis capacities seem to be implicated in the progress of different pathologies, the antioxidant properties of both groups of lipophilic compounds have been studied. The objective of this review was to analyze the state-of-the-art advances in this field. We conducted a systematic bibliographic search (Web of Science™ and Scopus®), followed by a comprehensive and critical description of the results, with special emphasis on highly cited and more recently published research. In addition to an evaluative description of the methodologies, this review discussed different approaches used to obtain a physiological perspective, from in vitro studies to in vivo assays using oxidative biomarkers. From a chemical viewpoint, many studies have demonstrated how a pigment's structure influences its antioxidant response and the underlying mechanisms. The major outcome is that this knowledge is essential for interpreting new data in a metabolic networks context in the search for more direct applications to health. A promising era is coming where the term "antioxidant" is understood in terms of its broadest significance.

5-cis-, Trans- and Total Lycopene Plasma Concentrations Inversely Relate to Atherosclerotic Plaque Burden in Newly Diagnosed Type 2 Diabetes Subjects

Diabetic subjects are at increased risk of cardiovascular disease. Atherosclerosis, the common soil of most of the cardiovascular complications, is more prevalent and extensive in this population due not only to hyperglycemia, insulin resistance, and dyslipidemia, but also to inflammation and oxidative stress. Lycopenes are bioactive compounds with antioxidant and anti-inflammatory activities mostly supplied by tomato and tomato byproducts. We investigated the association between circulating lycopenes and carotid plaque burden in diabetic patients, in a cross-sectional study in 105 newly diagnosed diabetic subjects. Atheroma plaque (wall thickness ≥ 1.5 mm), number of plaques, and plaque burden (sum of maximum heights of all plaques) were assessed by sonographic evaluation of carotid arteries. Plasma lycopenes (5-cis-, 9-cis-, 13-cis-, and trans-lycopene) were quantified by high performance liquid chromatography–mass spectrometry HPLC-MS. Atheroma plaque was observed in 75 participants, from which 38 presented one plaque and 37 two or more carotid plaques. No differences were observed in the plasmatic concentrations of lycopenes between subjects with and without atherosclerotic plaque presence. However, plaque burden was inversely associated with 5-cis-lycopene, all cis-lycopene isomers, trans-lycopene, and total lycopene isomers (all, p < 0.05). High plasma levels of lycopenes inversely relate to atherosclerotic burden. We provide novel evidence that suggests that the consumption of compounds found in tomato and tomato byproducts might be beneficial for the prevention of atherosclerosis.

The Beneficial Effects of Alpha Lipoic Acid Supplementation on Lp-PLA2 Mass and Its Distribution between HDL and apoB-Containing Lipoproteins in Type 2 Diabetic Patients: A Randomized, Double-Blind, Placebo-Controlled Trial

Lipoprotein-associated phospholipase A₂ (Lp-PLA2) is a new specific vascular inflammation biomarker that is carried by the lipoproteins in the blood and plays a prominent role in the pathogenesis of atherosclerosis. Increased Lp-PLA2 levels and impaired Lp-PLA2 distribution across high-density lipoprotein (HDL) and non-HDL lipoproteins have been reported in diabetic patients, which is associated with the increase in cardiovascular disease (CVD) risk. This study is aimed at investigating the effect of alpha lipoic acid (ALA), as an antioxidant with potential cardioprotective properties, on the Lp-PLA2 mass and its distribution in diabetic patients. In a double-blind, randomized, placebo-controlled clinical trial, seventy diabetic patients were randomly allocated to ALA (1200 mg ALA as two 600 mg capsules/day) and placebo (two maltodextrin capsules/day) groups. The serum levels of total Lp-PLA2 mass, HDL-Lp-PLA2, oxidized low-density lipoproteins (ox-LDL), apolipoprotein A1 (apo A1), lipid profiles, fasting blood sugar (FBS), and insulin were measured, and apolipoprotein B- (apoB-) associated Lp-PLA2 and homeostasis model of assessment index (HOMA-IR) were calculated at the baseline and after 8 weeks of intervention. ALA significantly decreased the ox-LDL, total Lp-PLA2 mass, apoB-associated Lp-PLA2, and percent of apoB-associated Lp-PLA2 and triglyceride and increased the percent of HDL-Lp-PLA2 compared with the placebo group but had no significant effect on HDL-Lp-PLA2 mass, apo A1, lipid profiles, and glycemic indices. There was a positive correlation between the reduction in the ox-LDL level and total Lp-PLA2 mass in the ALA group. In conclusion, ALA may decrease the CVD risk by reducing the ox-LDL and Lp-PLA2 mass and improving the Lp-PLA2 distribution among lipoproteins in type 2 diabetic patients.

Chemo-metric analysis of carotenoids, chlorophylls, and antioxidant activity of Trifolium hybridum

This work determined carotenoids and chlorophylls profiles, in addition, the antioxidant potential of Trifolium hybridum from different geographical regions. Carotenoids separation and identification were carried out using HPLC-DAD. Result revealed eight carotenoids and nine chlorophylls in all samples. The major carotenoids were 8-apo-carotenal, all-E-neoxanthin, phytofluene, all-E-flavoxanthin, all-E-lutein and all-E-β-carotene. The major chlorophylls were pheophytin a, pyropheophytin a, hydroxyl-pheophytin a', hydroxyl-pheophytin a chlorophyll b and its derivatives, chlorophyll a, hydroxyl-chlorophyll a, pheophytin b, and pyropheophytin a. The highest concentrations of carotenoid were in extracts from Dir samples (382.5 μg/g), and Buner sample (485.1 μg/g), followed by the Malakand (379.6 μg/g) and Swat (375.3 μg/g). The principal component analysis revealed significant correlation in carotenoids and chlorophylls. Significant variations in carotenoids, chlorophylls, total flavonoids, and total phenolic contents were observed among all selected samples. The carotenoid and chlorophylls profile of Trifolium hybridum described herein could be useful for food colourant development in food industries.

A new variety of purple tomato as a rich source of bioactive carotenoids and its potential health benefits

Carotenoid-rich fractions (CRF) from pulp and peel of a new variety of purple tomato were investigated in comparison to a Red Cherry variety regarding carotenoids characterization, antioxidant capacity, and inhibition of proliferation of four tumor cell lines. CRF from peel of Purple tomato contains lutein, lycopene, and β-carotene up to 6, 1.5, and 2.5 times more than that of Red Cherry and it exhibited the highest antioxidant activity at 400 μg/mL, reaching 82% and 97% in DPPH and ABTS^•+ assays, respectively. Besides that, the Purple peel showed the highest scavenging lipoperoxides capacity as well as displayed the highest ferric reducing antioxidant power compared to the other CRF. In turn, the Red Cherry pulp CRF showed the highest antiproliferative activity against four tumor cell lines (MCF-7, NCI-H460, HeLa, and HepG2) at non-toxic concentrations. High concentration of neurosporene, and lycopene in Red Cherry pulp CRF show to be related to the good antiproliferative activity found on it. Therefore, this new variety of nutrient-rich purple tomato could be explored as well as the commercial variety Red Cherry, since both are good sources of dietary carotenoids with health-promoting properties.

The non-homogenous distribution and aggregation of carotenoids in the stratum corneum correlates with the organization of intercellular lipids in vivo

The human stratum corneum (SC) contains an abundant amount of carotenoid antioxidants, quenching free radicals and thereby protecting the skin. For the precise measurements of the depth-dependent carotenoid concentration, confocal Raman microscopy is a suitable method. The quantitative concentration can be determined by the carotenoid-related peak intensity of a Gaussian function approached at ≈1524 cm^-1 using non-linear regression. Results show that the carotenoid concentration is higher at the superficial layers of the SC then decreases to a minimum at 20% SC depth and increases again towards the bottom of the SC. In the present work, two carotenoid penetration pathways into the SC are postulated. The first pathway is from the stratum granulosum to the bottom of the SC, while in the second pathway, the carotenoids are delivered to the skin surface by sweat and/or sebum secretion and penetrate from outside. The carotenoids are aggregated at the superficial layers, which are shown by high correlation between the aggregation states of carotenoids and the lateral organization of lipids. At the 30%-40% SC depths, the ordered and dense lipid molecules intensify the lipid-carotenoid interactions and weaken the carotenoid-carotenoid interaction and thus exhibit the disaggregation of carotenoids. At 90%-100% SC depths, the carotenoid-lipid interaction is weakened and the carotenoids have a tendency to be aggregated. Thus, the molecular structural correlation of carotenoid and SC lipid might be reserved in the intercellular space of the SC and also serves as the skeleton of the intercellular lipids.

Carotenoid Production by Rhodotorula mucilaginosa in Batch and Fed-Batch Fermentation Using Agroindustrial Byproducts

Carotenoids are natural pigments that can be produced through biotechnological processes. However, the costs are relatively high and can be minimized by using lower-cost substrates as alternative nutrient sources. The fed-batch fermentation is one of the techniques used to obtain a high biomass concentration and/or maximum production. Thus, the aim of this work is to produce carotenoids in batch and fed-batch fermentation with the yeast Rhodotorula mucilaginosa CCT 7688 using agroindustrial byproducts in the culture medium. Carotenoid production was increased using experimental designs, which modified the concentration of the agroindustrial medium. In batch production the highest concentrations of total carotenoids (1248.5 μg/L) and biomass (7.9 g/L) were obtained in the medium containing 70 g/L sugar cane molasses and 3.4 g/L corn steep liquor at 25 °C and 180 rpm in 168 h, demonstrating an increase of 17% when compared to the standard yeast malt medium (1200 μg/L). In the fed-batch production, different feeding strategies were tested with 30 g/L sugar cane molasses and 6.5 g/L corn steep liquor, reaching a total carotenoid production of 3726 μg/L and biomass concentration of 16 g/L. Therefore, the strategy of the fed-batch process resulted in an increase in the carotenoid production of approx. 400% compared to that in the batch process (740.3 μg/L). Thus, the R. mucilaginosa strain has the potential to produce carotenoids in agroindustrial medium.

Primary Screening of Antioxidant Activity, Total Polyphenol Content, Carotenoid Content, and Nutritional Composition of 13 Edible Flowers from Japan

Thirteen edible flowers, which are used as food ingredients in Japan, were evaluated as possible sources of antioxidants and biological compounds. The nutritional composition, total polyphenol content (TPC), carotenoid content, and antioxidant activity of the edible flowers were determined based on the oxygen radical absorbance capacity (ORAC). Water was the main constituent of edible flowers, and carbohydrates were the primary macronutrients. The TPC of the edible flowers varied from 1.47 to 13.08 mg gallic acid equivalent/g fresh weight (FW). Carotenoids, including β-carotene and β-cryptoxanthin, were detected mainly in the edible flowers with petal colors ranging from yellow to orange, but especially in primula and cosmos yellow flowers, which have yellow petals. The ORAC value of the hydrophilic extract (HORAC) of edible flowers was higher than the ORAC value of the lipophilic extract (LORAC). The total antioxidant capacity (TAC) ranged from 33.03 to 320.36 μM Trolox equivalent/g FW. The highest TPC and TAC were observed in cosmos yellow flowers. On the basis of Pearson's correlation coefficient, the HORAC value and the TPC of the analyzed edible flowers were highly correlated (r=0.736). This preliminary study indicates that edible flowers are a potential source of antioxidants, and the addition of edible flowers to the human diet may be associated with health benefits.

Glycation of Plant Proteins: Regulatory Roles and Interplay with Sugar Signalling?

Glycation can be defined as an array of non-enzymatic post-translational modifications of proteins formed by their interaction with reducing carbohydrates and carbonyl products of their degradation. Initial steps of this process rely on reducing sugars and result in the formation of early glycation products-Amadori and Heyns compounds via Schiff base intermediates, whereas their oxidative degradation or reactions of proteins with α-dicarbonyl compounds yield a heterogeneous group of advanced glycation end products (AGEs). These compounds accompany thermal processing of protein-containing foods and are known to impact on ageing, pathogenesis of diabetes mellitus and Alzheimer's disease in mammals. Surprisingly, despite high tissue carbohydrate contents, glycation of plant proteins was addressed only recently and its physiological role in plants is still not understood. Therefore, here we summarize and critically discuss the first steps done in the field of plant protein glycation during the last decade. We consider the main features of plant glycated proteome and discuss them in the context of characteristic metabolic background. Further, we address the possible role of protein glycation in plants and consider its probable contribution to protein degradation, methylglyoxal and sugar signalling, as well as interplay with antioxidant defense.

A Simple and Efficient Method for the Partial Synthesis of Pure (3R,3'S)-Astaxanthin from (3R,3'R,6'R)-Lutein and Lutein Esters via (3R,3'S)-Zeaxanthin and Theoretical Study of Their Formation Mechanisms

Carotenoids are natural compounds that have important roles in promoting and maintaining human health. Synthetic astaxanthin is a highly requested product by the aquaculture industry, but natural astaxanthin is not. Various strategies have been developed to synthesize this carotenoid. Nonetheless, these approaches have not only provided limited global yields, but its main commercial source also carries several health risks for humans. In this contribution, the one-pot base-catalyzed reaction of (3R,3'R,6'R)-lutein (1) esters has resulted in a successful isomerization process to easily obtain up to 95% meso-zeaxanthin (2), which in turn is oxidized to (3R,3'S)-astaxanthin (3) with a global yield of 68%. The same oxidation performed with UV irradiation (365 nm) for 5 min provided the highest global yield (76%). These chemical transformations have also been achieved with a significant reduction of the health risks associated with its potential human consumption. Furthermore, this is the first time only one of the configurational isomers has been obtained semisynthetically. The poorly understood formation mechanisms of these two compounds were also investigated using Density-Functional Theory (DFT) calculations. These theoretical studies revealed that the isomerization involves a base-catalyzed deprotonation at C-6', followed by C-4' protonation, while the oxidation occurs via free radical mechanisms.

Beneficial Role of Phytochemicals on Oxidative Stress and Age-Related Diseases

Aging is related to a number of functional and morphological changes leading to progressive decline of the biological functions of an organism. Reactive Oxygen Species (ROS), released by several endogenous and exogenous processes, may cause important oxidative damage to DNA, proteins, and lipids, leading to important cellular dysfunctions. The imbalance between ROS production and antioxidant defenses brings to oxidative stress conditions and, related to accumulation of ROS, aging-associated diseases. The purpose of this review is to provide an overview of the most relevant data reported in literature on the natural compounds, mainly phytochemicals, with antioxidant activity and their potential protective effects on age-related diseases such as metabolic syndrome, diabetes, cardiovascular disease, cancer, neurodegenerative disease, and chronic inflammation, and possibly lower side effects, when compared to other drugs.

Isolation, Identification of Carotenoid-Producing Rhodotorula sp. from Marine Environment and Optimization for Carotenoid Production

Carotenoids are natural pigments found in plants and microorganisms. These important nutrients play significant roles in animal health. In contrast to plant production, the advantages of microbial fermentation of carotenoids are the lower media costs, fast growth rate of microorganisms, and the ease of culture condition control. In this study, a colony of red pigment-producing yeast, Rhodotorula sp. RY1801, was isolated from the sediment of marine environment with the potential to produce carotenoids. Optimization of carotenoid production in Rhodotorula sp. RY1801 was also discussed. The optimum conditions found for carotenoid production were as follows: temperature, 28 °C; pH 5.0; carbon source, 10 g/L glucose, nitrogen source, 10 g/L yeast extract, maximum concentration of 987 µg/L of total carotenoids was obtained. The results of this study show that the isolated yeast strain Rhodotorula sp. RY1801 can potentially be used in future as a promising microorganism for the commercial production of carotenoids.

Health Benefits of Polyphenols and Carotenoids in Age-Related Eye Diseases

Oxidative stress and inflammation play a critical role in the initiation and progression of age-related ocular abnormalities as cataract, glaucoma, diabetic retinopathy, and macular degeneration. Therefore, phytochemicals with proven antioxidant and anti-inflammatory activities, such as carotenoids and polyphenols, could be of benefit in these diseases. We searched PubMed and Web of Science databases for original studies investigating the benefits of different carotenoids and polyphenols in age-related ophthalmic diseases. Our results showed that several polyphenols (such as anthocyanins, Ginkgo biloba, quercetin, and resveratrol) and carotenoids (such as lutein, zeaxanthin, and mezoxanthin) have shown significant preventive and therapeutic benefits against the aforementioned conditions. The involved mechanisms in these findings include mitigating the production of reactive oxygen species, inhibiting the tumor necrosis factor-α and vascular endothelial growth factor pathways, suppressing p53-dependent apoptosis, and suppressing the production of inflammatory markers, such as interleukin- (IL-) 8, IL-6, IL-1a, and endothelial leucocyte adhesion molecule-1. Consumption of products containing these phytochemicals may be protective against these diseases; however, adequate human data are lacking. This review discusses the role and mechanisms of polyphenols and carotenoids and their possible synergistic effects on the prevention and treatment of age-related eye diseases that are induced or augmented by oxidative stress and inflammation.

Synthesis and characterization of segmented poly(ester-urethane)s (PEUs) containing carotenoids

A series of three different xanthophylls such as lutein, zeaxanthin, and astaxanthin were used as chain extender agents in the synthesis of a new family of segmented poly(ester-urethane)s (PEUs) derived from poly(ε-caprolactone) (PCL).

Sensory acceptance and characterization of yoghurt supplemented with yacon syrup and cashew apple extract as a source of bioactive compounds

Abstract Yacon syrup (YS) and cashew apple extract (CAE) are products with high concentrations of bioactive compounds such as fructooligosaccharides and carotenoids, which exhibit prebiotic and antioxidant properties. The objective of this work was to evaluate the impact of YS and CAE on the chemical, physical, physicochemical and sensory properties when these products were incorporated into natural yoghurt. Initially, the YS and CAE were characterized by chemical, physical and physicochemical analyses. The bioactive compounds, such as carotenoids, fructooligosaccharides and phenolic compounds, and the antioxidant activity were also determined. After characterization, natural yoghurt was supplemented with YS and CAE in different concentrations as follows: formulation A (non-supplemented yoghurt, as the control), formulation B (yoghurt with the addition of 20% of YS), formulation C (yoghurt with the addition of 20% of YS and 10% of CAE) and formulation D (yoghurt with the addition of 20% of YS and 20% of CAE). The formulations were evaluated for their sensory acceptance (overall acceptance, texture and appearance) and purchase intent, and were then characterized by chemical, physicochemical and physical analyses. The results indicated that the YS and CAE presented high concentrations of bioactive compounds, such as fructooligosaccharides and carotenoids, respectively. In addition, when the yoghurt was supplemented with these products, this induced changes in the chemical, physicochemical and physical properties of the yoghurt. In the sensory analysis, all the formulations presented good acceptance. The results indicated that yoghurt could be considered as an interesting vehicle for YS and CAE, products with high levels of bioactive compounds that may exert beneficial effects on human health.

Fruit and vegetable consumption and its relation to risk of asthenopia among Chinese college students

AIM

To investigate the associations between fruit and vegetable consumption and risk of asthenopia among Chinese college students.

METHODS

A total of 1022 students were selected from five universities by a multi-stage stratified cluster sampling method. They were surveyed via a self-administered questionnaire including socio-demographic features, dietary and lifestyle habits, eye-related symptoms, eye care habits and history of diseases. Ascertainment of asthenopia was based on participants' subjectively reported symptoms. The associations between fruit and vegetable intake with asthenopia risk were assessed using multivariate logistic regression analysis.

RESULTS

There were no significant associations between total fruit and vegetable, total vegetable, or fruit and the risk of asthenopia. Higher intake of dark-green leafy vegetable was likely to be inversely associated with asthenopia risk [odd ratio (OR): 0.60; 95%CI: 0.37-0.97; P_trend=0.21] after controlling for nondietary and dietary risk factors. Stratified analysis showed that the inverse association between dark-green leafy vegetable intake and asthenopia risk was limited to participants with suboptimal eyesight (OR: 0.45; 95%CI: 0.25-0.82; P_trend=0.05), wearing glasses (OR: 0.35; 95%CI: 0.17-0.72; P_trend=0.03) or using computer ≥3h/d (OR: 0.48; 95%CI: 0.25-0.93; P_trend=0.08).

CONCLUSION

A higher consumption of dark-green leafy vegetable is associated with a lower asthenopia risk among college students with suboptimal eyesight and poor eye care habits.

Consumption of orange fermented beverage improves antioxidant status and reduces peroxidation lipid and inflammatory markers in healthy humans

BACKGROUND

Alcoholic fermentation of fruits has generated novel products with high concentrations of bioactive compounds and moderate alcohol content. The aim of this study was to evaluate the potential effect on cardiovascular risk factors of the regular consumption by healthy humans of a beverage obtained by alcoholic fermentation and pasteurization of orange juice.

RESULTS

Thirty healthy volunteers were enrolled in a randomized controlled study. The experimental group (n = 15) drank 500 mL orange beverage (OB) per day for 2 weeks (intervention phase), followed by a 3-week washout phase. Blood samples were collected at baseline (E-T0) and at the end of the intervention (E-T1) and washout (E-T2) phases. Controls (n = 15) did not consume OB during a 2-week period. OB intake significantly increased oxygen radical absorbance capacity (43.9%) and reduced uric acid (-8.9%), catalase (CAT) (-23.2%), thiobarbituric acid reactive substances (TBARS) (-30.2%) and C-reactive protein (-2.1%) (E-T1 vs. E-T0). These effects may represent longer-term benefits, given the decreased uric acid (-8.9%), CAT (-34.6%), TBARS (-48.4%) and oxidized low-density lipoprotein (-23.9%) values recorded after the washout phase (E-T2 vs. E-T0).

CONCLUSION

The regular consumption of OB improved antioxidant status and decreased inflammation state, lipid peroxidation and uric acid levels. Thus OB may protect the cardiovascular system in healthy humans and be considered a novel functional beverage. © 2017 Society of Chemical Industry.

Carotenoids: From Plants to Food and Feed Industries

In this review, carotenoids from plants are described, and their natural existence is addressed. Carotenoids are 40-carbon isoprenoid molecules that produce the red, yellow, and orange pigmentation found in nature. Various plants, microalgae, bacteria, and fungi are natural sources of carotenoids and are presented in detail. The chemistry of carotenoids and their classification is also described along with the effect of carotenoids on human health which is explained with focus on lutein-zeaxanthin, astaxanthin, canthaxanthin, capsanthin, and lycopene. Clinical studies suggest that carotenoid consumption is associated with lower risk of cardiovascular disease, cancer, and eye disease. Finally, another issue discussed is the role of carotenoids in animals and their feed with focus on birds, fish and crustaceans, livestock, and poultry.