High Levels Of Β-carotene Research Articles

Maximizing saffron apocarotenoid production in varied tomato fruit carotenoid contexts.

Saffron spice owes its commercial appreciation to its specific apocarotenoids: crocins, picrocrocin, and safranal. In Crocus sativus, these compounds are biosynthesized from zeaxanthin through oxidative cleavage by the carotenoid cleavage dioxygenase 2 (CCD2). Transgenic tomato plants expressing CsCCD2 in the fruit, named Tomaffron, accumulate high levels of saffron apocarotenoids despite the low substrate availability for CsCCD2. In the present study, CsCCD2 has been introduced into Xantomato; this tomato variety accumulates high levels of zeaxanthin and β-carotene in ripe fruit due to a combination of four mutant alleles. Xantomato and Tomaffron genotypes have been combined to optimize apocarotenoid production. The best transgenic lines accumulated 15 and 14 times more crocins and picrocrocin than Tomaffron, alongside a fourfold increase in β-carotene compared to Xantomato, albeit at a cost in fruit yield. Segregation of the four mutations has been carried out to find the best combination for obtaining high levels of saffron apocarotenoids without adverse effects on fruit yield. Plants harboring the high-pigmented 3 (hp3) and BETA (BSh) mutations accumulated 6 and 15 times more crocins and picrocrocin than Tomaffron, without observable pleiotropic effects. Additionally, those high levels of saffron apocarotenoids were obtained in fruit accumulating high levels of both lycopene and β-carotene independently or in combination, suggesting a regulatory role for the apocarotenoids produced and indicating that it is possible to increase the levels of both types of healthy promoting molecules simultaneously.

Characterization of Lipid Extracts from Different Colors of Peach Palm Fruits-Red, Yellow, Green, and White-Obtained through Ultrasound-Assisted Green Extraction.

This study represents a pioneering investigation and comparative analysis of lipid extracts from four different colors of peach palm (Bactris gasipaes Kunt) fruits-red, yellow, green, and white-by employing a green method based on ethanolic ultrasound-assisted extraction. This study examined the extraction yield, physico-chemical-quality attributes, chromatographic profiles (GC), color measurements, total carotenoid content, differential thermogravimetry (TG/DTA), and infrared spectroscopy (FTIR). The obtained lipid extracts displayed a high quality, considering the physico-chemical parameters of the Codex Alimentarius, and a fatty acids profile characterized by unsaturated fatty acids, notably omegas (ω-3, ω-6, and ω-9). The indices of atherogenicity (A.I.), thrombogenicity (I.T.), and hypocholesterolemic and hypercholesterolemic ratios revealed superior outcomes for the red peach palm lipid extract (approximately 0.35, 0.52, and 2.75, respectively), along with higher levels of β-carotene (748.36 µg of β-carotene per 100 g-1 of lipid extract) compared to the yellow, green, and white counterparts. Consequently, this research successfully demonstrates the efficacy of using a green extraction method in preserving the lipid's quality, which can display cardiovascular functionality and thermal stability. These findings underscore the considerable potential of peach palm lipid extract as a valuable raw material for diverse industrial applications across various sectors. The results support its utilization in the production of functional food products and nutraceuticals due to its favorable fatty acid composition, potent antioxidant properties exhibited by its high β-carotene content, and notable cardiovascular functionality indices.

Dunaliella β-Carotene Productivity Comparison Under In Vitro Conditions.

Some species of Dunaliella produce high levels of β-carotene, which is the largest natural Vitamin A source. β-carotene production in Dunaliella is expensive due to low yields obtained under culture conditions used. Since three decades ago synthetic β-carotene has dominated 98% of world market, even when synthetic is less bioactive than Dunaliella β-carotene molecule. In vitro experiments have been performed to increase β-carotene productivity in Dunaliella and some useful results have been obtained. In this review, culture conditions used in those experiments were compared to identify parameters that improved β-carotene productivity in Dunaliella. Comparison results show that β-carotene in vitro production can be increased regulating some specific culture conditions.

Research Progress in Heterologous Crocin Production.

Crocin is one of the most valuable components of the Chinese medicinal plant Crocus sativus and is widely used in the food, cosmetics, and pharmaceutical industries. Traditional planting of C. sativus is unable to fulfill the increasing demand for crocin in the global market, however, such that researchers have turned their attention to the heterologous production of crocin in a variety of hosts. At present, there are reports of successful heterologous production of crocin in Escherichia coli, Saccharomyces cerevisiae, microalgae, and plants that do not naturally produce crocin. Of these, the microalga Dunaliella salina, which produces high levels of β-carotene, the substrate for crocin biosynthesis, is worthy of attention. This article describes the biosynthesis of crocin, compares the features of each heterologous host, and clarifies the requirements for efficient production of crocin in microalgae.

Antioxidant and Biological Activities of Mahajanaka Mango Pulp Extract in Murine Models

Mahajanaka mango, a hybrid cultivar of Mangifera indica Linn., is a highly nutritional fruit that is popularly consumed in Thailand. It has been used in traditional medicine due to its abundance of phytonutrients. The present study aimed to investigate the chemical compositions and antioxidant activity of Mahajanaka mango pulp extract (MPE) in vitro. Additionally, we examined its biological activities, including the analgesic, anti-inflammatory, gastroprotective, and hepatoprotective effects of MPE, in murine models. MPE exhibited high levels of phenolic compounds, mangiferin, β-carotene, and vitamin C, and it potentially showed antioxidant properties in an ABTS scavenging assay. The animal results have revealed that oral administration of MPE (1000 mg/kg body weight (BW)) significantly decreased acetic acid-induced writhing responses in mice. Interestingly, local applications of MPE at 1 mg/ear ameliorated ethyl phenylpropiolate (EPP)-induced ear edema, while gavage of MPE at 1000 mg/kg BW significantly decreased carrageenan-induced hind paw edema in rats. MPE can also protect against gastric ulcers induced by stress, hydrochloric acid/ethanol, and indomethacin in rats. Indeed, MPE (250 mg/kg BW) markedly lowered the level of serum alanine aminotransferase activity and hepatic lipid accumulation in rats with CCl4- and paracetamol-induced hepatotoxicity. Taken together, the findings suggested that MPE exerts potent antioxidant, analgesic, anti-inflammatory, gastroprotective, and hepatoprotective effects.

Comparison of carotenoid, chlorophyll concentrations and their biosynthetic transcript levels in different coloured cauliflower

Carotenoids and chlorophylls are among the most widely distributed pigments in nature that play essential roles in the photosynthetic apparatus and confer diverse colours in plants. Among all vegetables, cauliflower (Brassica oleracea L. ssp. var. botrytis) is rich in phytochemicals and is an important crop grown all over the world. This study investigates carotenoid and chlorophyll concentrations in differently pigmented cultivars and elucidates the role of transcriptional regulation of carotenoid accumulation including lutein and β-carotene. Here, we characterised changes in pigments by UHPLC-DAD-ToF-MS and changes in transcript levels of carotenoid metabolic genes by qRT-PCR in florets and leaves of orange (‘Jaffa’ and ‘Sunset’), purple (‘Di Sicilia Violetto’ and ‘Graffiti’), green (‘Trevi’) and white (‘Clapton’) cultivars. Transcript levels of all carotenoid metabolic genes showed different transcript level patterns in the leaves and florets. Compared to the other cultivars, the orange cultivars had the highest levels of β-carotene in the florets and lutein in the leaves resulting in changes lutein/β-carotene ratios. In the green cultivar, higher transcript levels were also found, especially for phytoene synthase and phytoene desaturase genes of the core biosynthesis pathway. However, no increased carotenoid concentrations were observed, possibly due to a higher carotenoid turnover induced by the carotenoid cleavage dioxygenase 4 in the green cultivar. In the white (‘Clapton’) and purple (‘Di Sicilia Violetto’ and ‘Graffiti’) cultivars the phytoene desaturase transcript levels as well as carotenoid concentrations were low. Chlorophyll concentrations changed in trend comparable to the carotenoid concentrations and were only significantly lower in the leaves of the orange cultivar ‘Jaffa’. Also, the chlorophyll a/b ratio changed in ‘Jaffa’. In florets the highest chlorophylls concentrations were observed for the green cultivar (‘Trevi’) and the purple cultivar (‘Di Sicilia Violetto’). Taken together, the study demonstrates the complex source-sink relationship of carotenoid accumulation in different coloured cauliflower.

Formulation and Physical Stability Test of Red Fruit Oil (Pandanus conoideus Lam.) Emulgel Using Carbopol 940 Base as Wound Treatment

Red fruit ( Lam.) contains high levels of fatty acids, α-tocopherol, and β-carotene which can accelerate wound healing. Red fruit oil (RFO) is formulated as an emulgel because it is comfortable to use, has high penetration, and has a low risk of irritation. Emulgel RFO must meet the standards for physical properties and stability of topical preparations.The purpose of this study was to determine the effect of variations in RFO concentration on the physical properties and physical stability of the RFO emulgel. Emulgel was made with various RFO concentrations of 5% w/v (F1), 10% w/v (F2), and 15% w/v (F3). Then there was a physical evaluation and tested for physical stability after storage for 28 days at room temperature (30ºC±2ºC). Variations in RFO concentration decreased dispersion and adhesion values in the evaluation of physical qualities. In the 28-day storage stability test, variations in RFO concentration decreased the pH value, dispersion and increased adhesion. Emulgel RFO before and after the cycling test did not change. After performing the mechanical test, all the RFO emulgels did not occur in phase separation. It can be concluded that the variation of RFO concentration affects the physical properties, namely, dispersion and adhesion. However, it did not affect the organoleptic, homogeneity, and pH of the emulgel. After 28-day storage, variations in RFO concentration significantly affected pH, spreadability, and adhesion, while homogeneity and organoleptic had no significant effect. Variations in RFO concentration did not affect the stability of the cycling test and mechanical test.

The Tomato Juhwang Mutant Accumulates a High Level of β-Carotene and has a Long Shelf-Life

The Tomato Juhwang Mutant Accumulates a High Level of β-Carotene and has a Long Shelf-Life

Novel Insight into the Volatile Profile and Antioxidant Properties of Crocus sativus L. Flowers.

The current production system of saffron spice generates hundreds of tons of waste. Thus, the aim of this study was to value both saffron and its floral by-products as a source of natural bioactive extracts, studying the in vitro antioxidant capacity, the composition of the volatile fraction by GC-MS/MS, and the determination of crocetins esters by HPLC-PDA. Saffron stigmas and floral by-products showed a high content of polyphenols and different antioxidant properties. Floral bio-residues (tepals, stamens, and styles) presented a high concentration of anthocyanins, and stigmas had high levels of flavonoids, β-carotene, and total crocins. In stigmas, 25 different volatile components were found, with safranal the most relevant. Floral by-products volatile composition consisted of 55 compounds with varying amounts depending on the drying treatment; all the samples presented acetic acid, 2(5H)-furanone, and phenylethyl alcohol. Therefore, saffron stigmas and flower by-products represent a sustainable source of bioactive ingredients for innovative healthy food formulations.

Characterization of 75 Cultivars of Four Capsicum Species in Terms of Fruit Morphology, Capsaicinoids, Fatty Acids, and Pigments

Fruit quality has long been well known as an important prerequisite for evaluating pepper resources. In the study, 75 cultivars belonging to four Capsicum species were investigated on the bases of fruit morphology and concentrations of fruit secondary metabolites. The results showed that C. annuum had a greater variation than C. chinense and C. frutescens in terms of fruit weight, size and contents of carotenoids, anthocyanidins, and capsaicinoids. Moreover, there were significant differences in the concentrations of total phenol, total soluble sugar, total soluble solids, titratable acid, and total soluble protein of all samples. Capsaicin and dihydrocapsaicin were the most important capsaicinoids components in pepper fruits, of which C. chinense both had the highest levels, whereas some accessions of C. annuum were not detected. Eighteen fatty acids were detected in pepper fruits, and the dominant member was linoleic acid (a polyunsaturated fatty acid) therein. We integrated a set of methods for metabolites, and the results indicated that there was a positive correlation between concentrations of capsaicinoids and fatty acids. Four accessions had the highest contents of quality-related compounds, two of which belonged to C. chinense (S23 and S24) and possessed high levels of capsaicin. However, S67 had a high level of β-carotene and S68 contained higher contents of total fatty acid and ascorbic acid, and both of them belonged to C. annuum. This work could provide a valid experimental basis for the potential application value of the four accessions mentioned above.

Genome-Wide Identification of the B-Box Gene Family and Expression Analysis Suggests Their Potential Role in Photoperiod-Mediated β-Carotene Accumulation in the Endocarp of Cucumber (Cucumis sativus L.) Fruit.

Carotenoids are indispensable to plants and essential for human nutrition and health. Carotenoid contents are strongly influenced by light through light-responsive genes such as B-Box (BBX) genes. BBX proteins, a class of zinc-finger transcription factors, mediate many light-signaling pathways, leading to the biosynthesis of important metabolites in plants. However, the identification of the BBX gene family and expression analysis in response to photoperiod-mediated carotenoid accumulation in cucumber remains unexplored. We performed a genome-wide study and determined the expression of cucumber BBX genes (hereafter referred to as CsaBBXs genes) in the endocarp of Xishuangbanna cucumber fruit (a special type of cucumber accumulating a high level of β-carotene in the endocarp) using an RNA-seq analysis of plants previously subjected to two photoperiodic conditions. Here, 26 BBX family genes were identified in the cucumber genome and named serially CsaBBX1 through CsaBBX26. We characterized CsaBBX genes in terms of their phylogenetic relationships, exon-intron structures, cis-acting elements, and syntenic relationships with Arabidopsis thaliana (L.) Heynh. RNA-seq analysis revealed a varied expression of CsaBBX genes under photoperiod treatment. The analysis of CsaBBXs genes revealed a strong positive correlation between CsaBBX17 and carotenoid biosynthetic pathway genes (phytoene synthase, ζ-carotene desaturase, lycopene ε-cyclase, β-carotene hydroxylase-1), thus suggesting its involvement in β-carotene biosynthesis. Additionally, nine CsaBBX genes (CsaBBX 4,5,7,9,11, 13,15,17 and 22) showed a significant positive correlation with β-carotene content. The selected CsaBBX genes were verified by qRT-PCR and confirmed the validity of RNA-seq data. The results of this study established the genome-wide analysis of the cucumber BBX family and provide a framework for understanding their biological role in carotenoid accumulation and photoperiodic responses. Further investigations of CsaBBX genes are vital since they are promising candidate genes for the functional analysis of carotenoid biosynthesis and can provide genetic tools for the molecular breeding of carotenoids in plants.

Beta-carotene exerted anti-proliferative and apoptotic effect on malignant mesothelioma cells.

High blood levels of β-carotene and increased intake in the diets are inversely proportional to incidence of many cancer types. Antioxidant activity of β-carotene was proposed to be related with its antitumor effect. Despite this plant derivative substance being sought in many cancer types, the effectiveness of β-carotene against malignant mesothelioma remained unclear. Therefore, the present study aims to explore the impact of β-carotene on cell viability, apoptosis, and oxidative stress in mesothelioma cells. Human mesothelioma cell SPC212 were treated with β-carotene (3.125-200μM) for 24, 48, 72, and 96h. Cytotoxicity was measured with the MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide). Annexin-V/propidium iodide (PI) and caspase 3/7 biomarkers were used to identify apoptotic cells. Finally, the oxidative stress was evaluated with flow cytometry. The results of the measurements indicated a significant decline in viable mesothelioma cancer cell numbers upon β-carotene treatment in time- and concentration-dependent manner when compared to control cells. Furthermore, β-carotene treatment led to apoptosis induction according to both annexin V/PI and caspase 3/7 assays. Furthermore, β-carotene increased oxidative stress in SPC212 cells. These results show how β-carotene affects proliferative, apoptotic, and oxidative properties in SPC212 malignant pleural mesothelioma cells and provide useful insights into future studies.

Molecular Research Progress on Xishuangbanna Cucumber (Cucumis sativus L. var. Xishuangbannesis Qi et Yuan): Current Status and Future Prospects

The Xishuangbanna (XIS) cucumber is an important botanical variety, accumulating high levels of β-carotene (700 μg/100 g) in the endocarp of mature fruit compared with normal green/white flesh types (25–50 μg/100 g, fresh weight). β-carotene is an essential precursor of provitamin A synthesis required for human health, thus XIS cucumber is an appealing germplasm for vitamin A breeding programs. In this review, we highlighted the molecular research progress of XIS cucumber as well as the bottlenecks undermining its utilization in genetic breeding. The XIS cucumber was first reported in 1983; thereafter, the literature on XIS cucumber was sporadic until 2012 and 2013 following QTL mapping of the Ore gene and subsequent cloning of the CsaBCH1 gene, respectively. Whereas QTL mapping studies underlying its flowering time and fruit quality related traits have been reported, fine mapping of their candidate genes remains unknown. Cucumber fruits are mainly consumed at fresh immature stage; however, XIS cucumber accumulates β-carotene at mature fruit state, thus limiting the utilization of β-carotene derived from it. In our opinion, we believe that the production and commercialization of immature orange-fleshed cucumber would gain wider acceptance among consumers. Additionally, we highlighted a comprehensive breeding strategy, precisely for enhanced β-carotene accumulation based on prior studies of XIS cucumber coupled with those from other crops. In MAS, we proposed schematic molecular backcross breeding strategy using lines possessing both ore and fft1.1 loci. This review, therefore, provides insights of XIS cucumber research and opportunities for further genetic breeding.

An Evaluation of Phenolic Compounds, Carotenoids, and Antioxidant Properties in Leaves of South African Cultivars, Peruvian 199062.1 and USA's Beauregard.

In this study, leaves of sweet potato cultivars from South Africa (“Ndou,” “Bophelo,” “Monate,” and “Blesbok”), “Beauregard,” a sweet potato cultivar from the USA, and a Peruvian cultivar “199062. 1” were analyzed using UPLC/QTOF/MS and chemometrics, with the aim of characterizing the locally developed sweet potato cultivars and comparing them with already well-known established varieties on the market. A set of 13 phenolic compounds was identified. A partial least squares discriminant analysis, a hierarchical cluster analysis, and variables importance in projection were used to successfully distinguish sweet potato varieties based on their distinct metabolites. Caffeic acid enabled to distinguish Cluster 1 leaves of varieties (“Beauregard” and “Ndou”) from Cluster 2 (“199062.1,” “Bophelo,” “Monate,” and “Blesbok”). The leaves of “Bophelo” contained the highest concentrations of rutin, quercetin 3-O-galactoside, 3-caffeoylquinic acid (3-CQA), (5-CQA), 1,3 dicaffeoylquinic acid (1,3-diCQA), 1,4-diCQA, and 3,5-diCQA. Furthermore, Bophelo leaves showed the highest antioxidant activities (FRAP 19.69 mM TEACg−1 and IC50 values of (3.51 and 3.43 mg ml−1) for DPPH and ABTS, respectively, compared to the other varieties. Leaves of “Blesbok” contained the highest levels of β-carotene (10.27 mg kg−1) and zeaxanthin (5.02 mg kg−1) on a dry weight basis compared to all other varieties. This study demonstrated that the leaves of local cultivars “Bophelo” and “Blesbok” have the potential to become functional ingredients for food processing.

Analysis of Lipophilic Antioxidants in the Leaves of Kaempferia parviflora Wall. Ex Baker Using LC-MRM-MS and GC-FID/MS.

Lipophilic metabolites such as carotenoids, fatty acids, vitamin K1, phytosterols, and tocopherols are important antioxidants that are used in the cosmetics, foods, and nutraceutical industries. Recently, there has been a growing demand for the use of byproducts (wastes) as a potential source of industrially important compounds. The leaves of Kaempferia parviflora (black ginger) (KP-BG) are major byproducts of KP-BG cultivation and have been reported to contain several bioactive metabolites; however, the composition of lipophilic metabolites in KP-BG leaves has not been examined. In this study, the lipophilic antioxidant profile was analyzed in the leaves of KP-BG plants grown in vitro and ex vitro. Lipophilic compounds, namely carotenoids (80.40–93.84 µg/g fresh weight (FW)), tocopherols (42.23–46.22 µg/g FW), phytosterols (37.69–44.40 µg/g FW), and vitamin K1 (7.25–7.31 µg/g FW), were quantified using LC–MRM–MS. The fatty acid profile of the KP-BG leaves was identified using GC–FID/MS. The content of individual lipophilic compounds varied among the KP-BG leaves. Ex vitro KP-BG leaves had high levels of lutein (44.38 µg/g FW), α-carotene (14.79 µg/g FW), neoxanthin (12.30 µg/g FW), β-carotene (11.33 µg/g FW), violaxanthin (11.03 µg/g FW), α-tocopherol (39.70 µg/g FW), α-linolenic acid (43.12%), palmitic acid (23.78%), oleic acid (12.28%), palmitoleic acid (3.64%), total carotenoids (93.84 µg/g FW), and tocopherols (46.22 µg/g FW) compared with in vitro KP-BG leaves. These results indicate that ex-vitro-grown KP-BG leaves could be used as a valuable natural source for extracting important lipophilic antioxidants.

Assessing the Fatty Acid, Carotenoid, and Tocopherol Compositions of Seeds from Apple Cultivars (Malus domestica Borkh.) Grown in Norway.

Apple production generates large amounts of apple pomace including seeds, leading to high transportation costs, public health hazards and undesirable odor. A new reuse strategy of this kind of waste could solve environmental issues and/or create unconventional sources of health beneficial products. In total, seeds from 75 apple cultivars grown in Norway (both domestic and international) have been analyzed for the first time for oil content and fatty acid profile together with tocopherols and carotenoids quantification in defatted seeds. Seeds from cultivar Håkonseple had the highest oil content (22.10%), with linoleic, oleic acid, and palmitic acid as the most abundant fatty acids. The levels of β-carotene and lycopene carotenoids and α-tocopherol were the highest in defatted seeds of the cultivar Sureple Grøn. Principal component analysis separated cultivars according to the total oil content. The Norwegian apple cultivars Håkonseple, Kviteple, Tolleivseple, Vinterrosenstrips, and Tokheimseple are recommended for obtaining vegetable oil due to their high oil contents, while cultivar Sureple Grøn can be separated due to its high levels of β-carotene, lycopene and total tocopherols.

Bioavailability Studies of Vitamin A and E in Indigenous Vegetables and their Potential Use in the Management of HIV and AIDS

Levels of vitamins in selected indigenous vegetables in Butula, western Kenya were determined and foods containing high levels of vitamin A and E were used to make food formulation. The bioavailability of these vitamins in food formulation was estimated using algorithm procedure.
 Determination of β-carotene and α-tocopherol content was done using HPLC procedure. Fresh blanched vegetables contained high levels of β-carotene; 4000 − 9700 µg/100g and α-tocopherol levels; 3000 − 7350 µg/100g. Solar dried vegetables contained β-carotene levels ranging from 572 − 854 µg/g and α-tocopherol levels ranging from 281 to 673 µg/g dry weights. Solar dried vegetables contained significantly lower (P<0.05) amounts of β-carotene and α-tocopherol as compared with fresh vegetables. The mean serum retinol α-tocopherol and β-carotene levels were 0.937, 0.144 and 17.787µmol/l respectively. Bioavailability estimated using algorithm indicated a +2.17 change in serum β-carotene and +7.776 changes in serum α-tocopherol, a positive indication that consumption of indigenous vegetables can meet the recommended dietary allowances of vitamins A (750 µg retinol equivalent/day) and E (8 mg/day). The bioavailable vitamins are capable of boosting the immune system and therefore delay early use of ARV’S.

Determination of β-carotene and α-tocopherol Content in Selected Fresh and Dry Vegetables in Butula in Busia County

The study involved the determination of β-carotene and α-tocopherol content in selected fresh and dry vegetables (amaranthus, cowpea leaves, nightshade, slender leaf, pumpkin leaves and frying spider) using High Performance Liquid Chromatography (HPLC) procedure. Fresh blanched vegetables contained high levels of β-carotene; 4000-9700µg/100g and α-tocopherol levels; 3000-7360µg/100g (WW). The solar dried vegetables contained β- carotene levels ranging from 572 to 854µg g-1 dry weight (DW) and α-tocopherol levels ranging from 281 to 673µg g-1 (DW). Solar dried vegetables contained significantly lower (P<0.05) amounts of β-carotene and α-tocopherol which were moderately bioavailable when mixed in good proportion to meet Recommended Dietary Allowance (RDA) of vitamins A and E; which are 750µg retinol equivalent/day and 8mg/day respectively. The results will provide nutritional information on the indigenous vegetables grown in Butula in Busia County.

Plant apocarotenoid metabolism utilizes defense mechanisms against reactive carbonyl species and xenobiotics.

Carotenoid levels in plant tissues depend on the relative rates of synthesis and degradation of the molecules in the pathway. While plant carotenoid biosynthesis has been extensively characterized, research on carotenoid degradation and catabolism into apocarotenoids is a relatively novel field. To identify apocarotenoid metabolic processes, we characterized the transcriptome of transgenic Arabidopsis (Arabidopsis thaliana) roots accumulating high levels of β-carotene and, consequently, β-apocarotenoids. Transcriptome analysis revealed feedback regulation on carotenogenic gene transcripts suitable for reducing β-carotene levels, suggesting involvement of specific apocarotenoid signaling molecules originating directly from β-carotene degradation or after secondary enzymatic derivatizations. Enzymes implicated in apocarotenoid modification reactions overlapped with detoxification enzymes of xenobiotics and reactive carbonyl species (RCS), while metabolite analysis excluded lipid stress response, a potential secondary effect of carotenoid accumulation. In agreement with structural similarities between RCS and β-apocarotenoids, RCS detoxification enzymes also converted apocarotenoids derived from β-carotene and from xanthophylls into apocarotenols and apocarotenoic acids in vitro. Moreover, glycosylation and glutathionylation-related processes and translocators were induced. In view of similarities to mechanisms found in crocin biosynthesis and cellular deposition in saffron (Crocus sativus), our data suggest apocarotenoid metabolization, derivatization and compartmentalization as key processes in (apo)carotenoid metabolism in plants.

Association of serum levels of antioxidant micronutrients with mortality in US adults: National Health and Nutrition Examination Survey 1999-2002.

To examine associations between serum antioxidant levels and mortality (all-cause, cancer and CVD) among US adults. We examined the risk of death from all-cause and cause-specific mortality associated with serum antioxidant (vitamin E and carotenoids) and vitamin A levels using Cox regression models to estimate hazards ratios (HR) and 95 % CI. The National Health and Nutrition Examination Survey (NHANES) 1999-2002 was followed up through 31 December 2015. The NHANES 1999-2002 cohort included 8758 participants aged ≥ 20 years. Serum carotenoid levels were only assessed for the 1999-2000 cycle. Therefore, sample size for each assessed antioxidant ranged from 4633 to 8758. Serum vitamin E level was positively associated with all-cause mortality (HR = 1·22, 95 % CI 1·04, 1·43, highest v. lowest quartile). No other antioxidants were associated with mortality in overall analysis. In race/ethnicity-specific analyses, high vitamin E and α-tocopherol levels were associated with increased risk of all-cause mortality among non-Hispanic Whites. Among non-Hispanic Blacks, serum α-tocopherol level was associated with decreased risk of cancer mortality (HR = 0·30, 95 % CI 0·12, 0·75, third v. first quartile) and total carotenoid levels with reduced risk of CVD mortality (HR = 0·26; 95 % CI 0·07, 0·97, second v. lowest quartile). Hispanics with high β-carotene levels had reduced risk of CVD mortality. Serum antioxidant levels may be related to mortality; these associations may differ by race/ethnicity and appeared to be non-linear for all-cause and cause-specific mortality. Further studies are needed to confirm our results.