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BioMed Research International 2022Oxidative stress is one of the common factors leading to age-related eye diseases in older adults. Factors such as high oxygen consumption, high concentration of... (Review)
Review
Oxidative stress is one of the common factors leading to age-related eye diseases in older adults. Factors such as high oxygen consumption, high concentration of polyunsaturated fatty acids, and cumulative exposure to high-energy visible light in the eyes, lead to excessive generation of reactive oxygen species, hence triggering apoptosis of ocular cells and giving rise to ophthalmic diseases. Dietary supplements such as carotenoids, anthocyanins, and vitamins have antioxidant properties which may be of benefit in retaining better vision or reversing vision impairment; thus, studies have been conducted to understand the role of dietary supplements in the treatment or prevention of ophthalmic diseases. While high concentration of carotenoids such as lutein and zeaxanthin decrease the risk of developing age-related macular disease, anthocyanins and vitamins play a role in the treatment and prevention of other ophthalmic diseases: saffron extract reduced intraocular pressure in glaucoma patients; bilberry extract prevented impairments in lenses and retina, as well as alleviate symptoms of dry eye disease; high concentration of beta-carotene may reduce the risk of developing cataract. Further studies with clinical measurements are required to investigate the effectiveness of antioxidants on visual function and ophthalmic diseases.
Topics: Aged; Aging; Anthocyanins; Antioxidants; Carotenoids; Dietary Supplements; Humans; Lutein; Reactive Oxygen Species; Retina; Vitamin A; Vitamins; Zeaxanthins; beta Carotene
PubMed: 36225983
DOI: 10.1155/2022/5810373 -
ELife Sep 2020Carotenoids are essential in oxygenic photosynthesis: they stabilize the pigment-protein complexes, are active in harvesting sunlight and in photoprotection. In plants,...
Carotenoids are essential in oxygenic photosynthesis: they stabilize the pigment-protein complexes, are active in harvesting sunlight and in photoprotection. In plants, they are present as carotenes and their oxygenated derivatives, xanthophylls. While mutant plants lacking xanthophylls are capable of photoautotrophic growth, no plants without carotenes in their photosystems have been reported so far, which has led to the common opinion that carotenes are essential for photosynthesis. Here, we report the first plant that grows photoautotrophically in the absence of carotenes: a tobacco plant containing only the xanthophyll astaxanthin. Surprisingly, both photosystems are fully functional despite their carotenoid-binding sites being occupied by astaxanthin instead of β-carotene or remaining empty (i.e. are not occupied by carotenoids). These plants display non-photochemical quenching, despite the absence of both zeaxanthin and lutein and show that tobacco can regulate the ratio between the two photosystems in a very large dynamic range to optimize electron transport.
Topics: Photosynthesis; Plants, Genetically Modified; Nicotiana; Xanthophylls; beta Carotene
PubMed: 32975516
DOI: 10.7554/eLife.58984 -
Molecules (Basel, Switzerland) Feb 2022Carotenoids represent a class of pigmented terpenoids. They are distributed in all taxonomic groups of fungi. Most of the fungal carotenoids differ in their chemical... (Review)
Review
Carotenoids represent a class of pigmented terpenoids. They are distributed in all taxonomic groups of fungi. Most of the fungal carotenoids differ in their chemical structures to those from other organisms. The general function of carotenoids in heterotrophic organisms is protection as antioxidants against reactive oxygen species generated by photosensitized reactions. Furthermore, carotenoids are metabolized to apocarotenoids by oxidative cleavage. This review presents the current knowledge on fungal-specific carotenoids, their occurrence in different taxonomic groups, and their biosynthesis and conversion into trisporic acids. The outline of the different pathways was focused on the reactions and genes involved in not only the known pathways, but also suggested the possible mechanisms of reactions, which may occur in several non-characterized pathways in different fungi. Finally, efforts and strategies for genetic engineering to enhance or establish pathways for the production of various carotenoids in carotenogenic or non-carotenogenic yeasts were highlighted, addressing the most-advanced producers of each engineered yeast, which offered the highest biotechnological potentials as production systems.
Topics: Biological Evolution; Biological Transport; Biosynthetic Pathways; Carotenoids; Fatty Acids, Unsaturated; Fungi; Gene Expression Regulation, Fungal; Genetic Engineering; Mutagenesis; beta Carotene
PubMed: 35209220
DOI: 10.3390/molecules27041431 -
Food Research International (Ottawa,... Mar 2021The 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...
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.
Topics: Carotenoids; Diospyros; Fruit; Lutein; Zeaxanthins
PubMed: 33641941
DOI: 10.1016/j.foodres.2020.109882 -
Nature Communications May 2022The endoperoxides of β-carotene (βCar-EPOs) are regarded as main products of the chemical deactivation of O by β-carotene, one of the most important antioxidants,...
The endoperoxides of β-carotene (βCar-EPOs) are regarded as main products of the chemical deactivation of O by β-carotene, one of the most important antioxidants, following a concerted singlet-singlet reaction. Here we challenge this view by showing that βCar-EPOs are formed in the absence of O in a non-concerted triplet-triplet reaction: O + β-carotene → βCar-EPOs, in which β-carotene manifests a strong biradical character. Thus, the reactivity of β-carotene towards oxygen is governed by its excited triplet state. βCar-EPOs, while being stable in the dark, are photochemically labile, and are a rare example of nonaromatic endoperoxides that release O, again not in a concerted reaction. Their light-induced breakdown triggers an avalanche of free radicals, which accounts for the pro-oxidant activity of β-carotene and the puzzling swap from its anti- to pro-oxidant features. Furthermore, we show that βCar-EPOs, and carotenoids in general, weakly sensitize O. These findings underlie the key role of the triplet state in determining the chemical and photophysical features of β-carotene. They shake up the prevailing models of carotenoid photophysics, the anti-oxidant functioning of β-carotene, and the role of O in chemical signaling in biological photosynthetic systems. βCar-EPOs and their degradation products are not markers of O and oxidative stress but of the overproduction of extremely hazardous chlorophyll triplets in photosystems. Hence, the chemical signaling of overexcitation of the photosynthetic apparatus is based on a chlorophyll-β-carotene relay, rather than on extremely short-lived O.
Topics: Carotenoids; Chlorophyll; Oxygen; Photosynthesis; Reactive Oxygen Species; beta Carotene
PubMed: 35513374
DOI: 10.1038/s41467-022-30095-z -
Molecules (Basel, Switzerland) Dec 2022Carotenoid compounds are ubiquitous in nature, providing the characteristic colouring of many algae, bacteria, fruits and vegetables. They are a critical component of... (Review)
Review
Carotenoid compounds are ubiquitous in nature, providing the characteristic colouring of many algae, bacteria, fruits and vegetables. They are a critical component of the human diet and play a key role in human nutrition, health and disease. Therefore, the clinical importance of qualitative and quantitative carotene content analysis is increasingly recognised. In this review, the structural and optical properties of carotenoid compounds are reviewed, differentiating between those of carotenes and xanthophylls. The strong non-resonant and resonant Raman spectroscopic signatures of carotenoids are described, and advances in the use of Raman spectroscopy to identify carotenoids in biological environments are reviewed. Focus is drawn to applications in nutritional analysis, optometry and serology, based on in vitro and ex vivo measurements in skin, retina and blood, and progress towards establishing the technique in a clinical environment, as well as challenges and future perspectives, are explored.
Topics: Humans; Lutein; Spectrum Analysis, Raman; beta Carotene; Carotenoids; Xanthophylls; Zeaxanthins
PubMed: 36558154
DOI: 10.3390/molecules27249017 -
Nutrients Jul 2022Paraoxonase 1 (PON1) is an antioxidant enzyme attached to HDL with an anti-atherogenic potential. It protects LDL and HDL from lipid peroxidation. The enzyme is... (Review)
Review
Paraoxonase 1 (PON1) is an antioxidant enzyme attached to HDL with an anti-atherogenic potential. It protects LDL and HDL from lipid peroxidation. The enzyme is sensitive to various modulating factors, such as genetic polymorphisms as well as pharmacological, dietary (including carotenoids), and lifestyle interventions. Carotenoids are nutritional pigments with antioxidant activity. The aim of this review was to gather evidence on their effect on the modulation of PON1 activity and gene expression. Carotenoids administered as naturally occurring nutritional mixtures may present a synergistic beneficial effect on PON1 status. The effect of carotenoids on the enzyme depends on age, ethnicity, gender, diet, and PON1 genetic variation. Carotenoids, especially astaxanthin, β-carotene, and lycopene, increase PON1 activity. This effect may be explained by their ability to quench singlet oxygen and scavenge free radicals. β-carotene and lycopene were additionally shown to upregulate PON1 gene expression. The putative mechanisms of such regulation involve PON1 CpG-rich region methylation, Ca(2+)/calmodulin-dependent kinase II (CaMKKII) pathway induction, and upregulation via steroid regulatory element-binding protein-2 (SREBP-2). More detailed and extensive research on the mechanisms of PON1 modulation by carotenoids may lead to the development of new targeted therapies for cardiovascular diseases.
Topics: Antioxidants; Aryldialkylphosphatase; Carotenoids; Gene Expression; Lycopene; beta Carotene
PubMed: 35889799
DOI: 10.3390/nu14142842 -
Marine Drugs Sep 2021Acute inflammation is a key component of the immune system's response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed... (Review)
Review
Acute inflammation is a key component of the immune system's response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.
Topics: Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Aquatic Organisms; Carotenoids; Microalgae
PubMed: 34677429
DOI: 10.3390/md19100531 -
PloS One 2015Many epidemiologic studies have investigated the association between carotenoids intake and risk of Prostate cancer (PCa). However, results have been inconclusive. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Many epidemiologic studies have investigated the association between carotenoids intake and risk of Prostate cancer (PCa). However, results have been inconclusive.
METHODS
We conducted a systematic review and dose-response meta-analysis of dietary intake or blood concentrations of carotenoids in relation to PCa risk. We summarized the data from 34 eligible studies (10 cohort, 11 nested case-control and 13 case-control studies) and estimated summary Risk Ratios (RRs) and 95% confidence intervals (CIs) using random-effects models.
RESULTS
Neither dietary β-carotene intake nor its blood levels was associated with reduced PCa risk. Dietary α-carotene intake and lycopene consumption (both dietary intake and its blood levels) were all associated with reduced risk of PCa (RR for dietary α-carotene intake: 0.87, 95%CI: 0.76-0.99; RR for dietary lycopene intake: 0.86, 95%CI: 0.75-0.98; RR for blood lycopene levels: 0.81, 95%CI: 0.69-0.96). However, neither blood α-carotene levels nor blood lycopene levels could reduce the risk of advanced PCa. Dose-response analysis indicated that risk of PCa was reduced by 2% per 0.2mg/day (95%CI: 0.96-0.99) increment of dietary α-carotene intake or 3% per 1mg/day (95%CI: 0.94-0.99) increment of dietary lycopene intake.
CONCLUSIONS
α-carotene and lycopene, but not β-carotene, were inversely associated with the risk of PCa. However, both α-carotene and lycopene could not lower the risk of advanced PCa.
Topics: Carotenoids; Dose-Response Relationship, Drug; Humans; Lycopene; Male; Observational Studies as Topic; Prostatic Neoplasms; Risk
PubMed: 26372549
DOI: 10.1371/journal.pone.0137427 -
Postepy Higieny I Medycyny... Apr 2015Human organisms have many defence mechanisms able to neutralise the harmful effects of the reactive species of oxygen. Antioxidants play an important role in reducing... (Review)
Review
Human organisms have many defence mechanisms able to neutralise the harmful effects of the reactive species of oxygen. Antioxidants play an important role in reducing the oxidative damage to the human organism. Carotenoids are among the strongest antioxidants. They have 11 coupled double bonds, so they can be classified as polyisoprenoids, show low polarity and can occur in acyclic, monocyclic or bicyclic forms. The carotenoids of the strongest antioxidant properties are lycopene, lutein, astaxanthin and β-carotene. Carotenoids with strong antioxidant properties have found wide application in medical, pharmaceutical and cosmetic industries. These compounds are highly active against both reactive oxygen species and free radicals. Comparing β-carotene, astaxanthin and lycopene with other antioxidants (e.g. vitamin C and E), it can be concluded that these compounds have higher antioxidant activity, e.g. against singlet oxygen. Astaxanthin is a stronger antioxidant compared to β-carotene, vitamin E and vitamin C, respectively 54, 14 and 65 times. Carotenoids have a salutary effect on our body, making it more resistant and strong to fight chronic diseases. The purpose of this article is to review the literature concerning free radicals and their adverse effects on the human body and carotenoids, as strong, natural antioxidants.
Topics: Antioxidants; Carotenoids; Free Radicals; Humans; Oxidative Stress; Reactive Oxygen Species
PubMed: 25897101
DOI: 10.5604/17322693.1148335