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Antioxidants (Basel, Switzerland) Jun 2020In this study, we investigated the formation of stable radicals and compounds related to antioxidants in seeds using high performance liquid chromatography (HPLC) and...
In this study, we investigated the formation of stable radicals and compounds related to antioxidants in seeds using high performance liquid chromatography (HPLC) and X-band electron paramagnetic resonance imaging (EPRI). The seed coat extracts exhibited antioxidant activity in both in vitro and cell-based studies. The extracts inhibited reactive oxygen and reactive nitrogen species production in cell-based studies. HPLC chromatograms indicated that hydrophilic antioxidant compounds-namely, gallic acid, gallocatechin, epigallocatechin, caffeine, catechin, epicatechin, and epicatechin gallate-were found in the methanolic extract. Lipophilic antioxidant compounds-including α-tocopherol, γ-tocopherol, β-tocopherol, δ-tocopherol, α-tocotrienol, γ-tocotrienol, and δ-tocotrienol-were found in the hexane extract. EPRI primarily detected paramagnetic species in seed coats. These radical species were stable organic radicals based on the peak-to-peak line width and -values. The signals from these stable radicals were strong and stable with a -value of 2.002. Noninvasive EPRI of the radicals present in seeds indicated that the stable radicals were essentially located in the seed coats. The EPRI of the cotyledon demonstrated that additional radicals were localized at an apex of the cotyledon. The results indicated that the stable radicals detected by EPRI and the hydrophilic and lipophilic antioxidant compounds analyzed by HPLC were related to antioxidant reactants and products.
PubMed: 32516915
DOI: 10.3390/antiox9060493 -
Oxidative Medicine and Cellular... 2020It remains unknown how different glucose tolerance status affects the relationships between dietary intake of different tocopherol isoforms (-, -, -, and -tocopherol)...
Potential Protective Effect of Dietary Intake of Non--Tocopherols on Cellular Aging Markers Mediated by Tumor Necrosis Factor- in Prediabetes: A Cross-Sectional Study of Chinese Adults.
It remains unknown how different glucose tolerance status affects the relationships between dietary intake of different tocopherol isoforms (-, -, -, and -tocopherol) and cellular aging, oxidative stress, and inflammatory markers. The authors conducted a cross-sectional study among 582 Chinese adults with different glucose tolerance status to explore the association between dietary intake of different tocopherol isoforms and cellular aging, oxidative stress, and inflammatory markers. The inverse correlations between non--tocopherols and tumor necrosis factor-alpha (TNF-) varied substantially across different glucose tolerance status, with the strongest observed in prediabetes ( = -0.33 for -/-tocopherol, = -0.37 for -tocopherol, < 0.01), followed by normal glucose tolerance (NGT). While such correlations were abolished in established diabetes. Furthermore, within prediabetes, the strongest inverse correlations between non--tocopherols and TNF- were observed in impaired fasting glucose (IFG) ( = -0.42 for -/-tocopherol, = -0.55 for -tocopherol, < 0.01), while such correlations were significantly attenuated in individuals with impaired glucose tolerance (IGT) and IFG+IGT. And mediation model analysis displayed that TNF- mediated the protective effect of non--tocopherols on leukocyte telomere length and mitochondrial DNA copy number, which was uniquely observed in prediabetes, while such mediation effect was statistically nonsignificant in NGT and established diabetes. In conclusion, our findings indicate that dietary intake of non--tocopherols might protect against cellular aging markers mediated by TNF- in prediabetes. Individuals with prediabetes, especially for IFG, might benefit from increasing dietary intake of non--tocopherol in alleviating inflammation and cellular aging, which might provide a new dietary avenue for delaying diabetes onset.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Blood Glucose; Cellular Senescence; China; Cross-Sectional Studies; DNA Copy Number Variations; Dietary Supplements; Humans; Middle Aged; Prediabetic State; Tocopherols; Tumor Necrosis Factor-alpha; Young Adult
PubMed: 32509152
DOI: 10.1155/2020/7396801 -
Food Science and Biotechnology Apr 2020Effects of 1,2-dioleoyl--glycero-3-phosphocholine (DOPC) on the oxidative stability were determined in soybean oil-water system at different locations including at the...
Effects of 1,2-dioleoyl--glycero-3-phosphocholine (DOPC) on the oxidative stability were determined in soybean oil-water system at different locations including at the interface of air-oil, in the middle of oil, and at the interface of oil-water. Also, profile changes of tocopherols were determined during UV irradiation for 18 days. Although no significant changes in tocopherol profiles were observed at three different locations irrespective of DOPC from 0 to 1250 μmol/kg oil, addition of DOPC increased total tocopherols, α-tocopherol, and δ-tocopherol whereas content of β + γ tocopherols did not increase at any locations. Moisture content in water-oil interface was higher than other locations while those were not consistent at different DOPC concentration. Added DOPC significantly decreased oxidative stability from 250 to 830 μmol/kg oil compared to controls (< 0.05) whereas 1250 μmol/kg oil DOPC increased oxidative stability. Stabilities of tocopherols especially α-tocopherol were lower in oil-water system than those in bulk oil at UV irradiation.
PubMed: 32296558
DOI: 10.1007/s10068-019-00676-8 -
Antioxidants (Basel, Switzerland) Feb 2020Most of the biological impacts of Vitamin E, including the redox effects, have been raised from studies with α-tocopherol only, despite the fact that...
Most of the biological impacts of Vitamin E, including the redox effects, have been raised from studies with α-tocopherol only, despite the fact that tocopherol-containing foods carry mixed tocopherol isomers. Here, we investigated the cellular mechanisms involved in the immediate antioxidant responses evoked by α-, γ- and δ-tocopherol in Caco-2 cells. In order to track the cytosolic redox impact, we performed imaging on cells expressing HyPer, a fluorescent redox biosensor, while cytosolic calcium fluctuations were monitored by means of Fura-2 dye and imaging. With this approach, we could observe fast cellular responses evoked by the addition of α-, γ- and δ-tocopherol at concentrations as low as 2.5 μM. Each isomer induced rapid and consistent increases in cytosolic calcium with fast kinetics, which were affected by chelation of extracellular Ca, suggesting that tocopherols promoted a calcium entry upon the contact with the plasma membrane. In terms of redox effects, δ-tocopherol was the only isomer that evoked a significant change in the HyPer signal at 5 μM. By mimicking Ca entry with ionomycin and monensin, a decline in the HyPer signal was induced as well. Finally, by silencing calcium with 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), an intracellular Ca chelator, none of the isomers were able to induce redox changes. Altogether, our data indicate that an elevation in cytoplasmic Ca is necessary for the development of a tocopherol-induced antioxidant impact on the cytoplasm of Caco-2 cells reported by HyPer biosensor.
PubMed: 32075011
DOI: 10.3390/antiox9020155 -
Molecules (Basel, Switzerland) Dec 2019Avocado (a fruit that represents a billion-dollar industry) has become a relevant crop in global trade. The benefits of eating avocados have also been thoroughly...
Avocado (a fruit that represents a billion-dollar industry) has become a relevant crop in global trade. The benefits of eating avocados have also been thoroughly described as they contain important nutrients needed to ensure biological functions. For example, avocados contain considerable amounts of vitamins and other phytonutrients, such as carotenoids (e.g., β-carotene), which are fat-soluble. Hence, there is a need to assess accurately these types of compounds. Herein we describe a method that chromatographically separates commercial standard solutions containing both fat-soluble vitamins (vitamin A acetate and palmitate, Vitamin D and D, vitamin K, α-, δ-, and γ-vitamin E isomers) and carotenoids (β-cryptoxanthin, zeaxanthin, lutein, β-carotene, and lycopene) effectively (i.e., analytical recoveries ranging from 80.43% to 117.02%, for vitamins, and from 43.80% to 108.63%). We optimized saponification conditions and settled at 80 °C using 1 mmol KOH L ethanol during 1 h. We used a non-aqueous gradient that included methanol and methyl -butyl ether (starting at an 80:20 ratio) and a C chromatographic column to achieve analyte separation (in less than 40 min) and applied this method to avocado, a fruit that characteristically contains both types of compounds. We obtained a method with good linearity at the mid to low range of the mg L (determination coefficients 0.9006-0.9964). To determine both types of compounds in avocado, we developed and validated for the simultaneous analysis of carotenoids and fat-soluble vitamins based on liquid chromatography and single quadrupole mass detection (LC/MS). From actual avocado samples, we found relevant concentrations for cholecalciferol (ranging from 103.5 to 119.5), δ-tocopherol (ranging from 6.16 to 42.48), and lutein (ranging from 6.41 to 15.13 mg/100 g dry weight basis). Simmonds cultivar demonstrated the higher values for all analytes (ranging from 0.03 (zeaxanthin) to 119.5 (cholecalciferol) mg/100 g dry weight basis).
Topics: Carotenoids; Chromatography, Liquid; Green Chemistry Technology; Humans; Mass Spectrometry; Persea; Reproducibility of Results; Solubility; Vitamins
PubMed: 31835535
DOI: 10.3390/molecules24244517 -
Food Science and Biotechnology Dec 2019Interaction between tocopherol homologs and peppermint extract added to oil-in-water emulsions was studied during iron-catalyzed oxidation. Emulsions consisted of...
Interaction between tocopherol homologs and peppermint extract added to oil-in-water emulsions was studied during iron-catalyzed oxidation. Emulsions consisted of tocopherol-stripped soybean oil and citrate buffer (4:6, w/w) with/without addition of peppermint extract (400 mg/kg) and α-, γ-, or δ-tocopherol (600 mg/kg), and were oxidized in the iron presence at 25 °C. Lipid oxidation of emulsions was evaluated based on hydroperoxide contents and -anisidine values. Lipid oxidative stability of emulsions was improved by added peppermint extract, and co-added γ- and δ-tocopherols further reduced lipid oxidation, however, α-tocopherol increased it. Tocopherol contents did not change during oxidation. Polyphenol degradation in the emulsion with added peppermint extract was lower and slower by γ- and δ-tocopherols, however, α-tocopherol showed opposite results. The results suggest that co-addition of tocopherols to the emulsion containing peppermint extract shift a major role of polyphenols as antioxidants from scavenging lipid (peroxy) radicals to tocopherol radical scavenging.
PubMed: 31807340
DOI: 10.1007/s10068-019-00613-9 -
Journal of Food Science and Technology Oct 2019Sacha inchi oil (SIO) is one of the largest vegetable oil exports in Peru, used for consumption, in the food industry, cosmetics, and pharmaceuticals; it represents a...
Sacha inchi oil (SIO) is one of the largest vegetable oil exports in Peru, used for consumption, in the food industry, cosmetics, and pharmaceuticals; it represents a significant economic income for producers. This study addresses the characterization and quantification of fatty acids, tocopherols, sterols, and alcohols of commercial Sacha inchi oils from Peru. Some of the SIO samples received had a high substance consistency, while others differed in the compounds studied. The results showed that some of the commercialized oils present high levels of γ-tocopherol and δ-tocopherol, while other samples had variable fatty acid compositions; especially in α-linolenic, linoleic, oleic and palmitic acids. Fourteen sterols and eleven alcohols were identified (β-sitosterol, stigmasterol, campesterol, Δ5-avenasterol, triterpene alcohol, lanosterol isomer 1 and cycloartenol) being the major components. Some SIO samples presented the following ratios: The δ-tocopherol/γ-tocopherol ratio was 0.33-0.81, ω-6/ω-3 ratio was 0.77 and a stigmasterol/campesterol ratio of 3.13. The presence of brassicasterol in some commercial oils indicates the addition of rapeseed or canola oil. Tocopherols, fatty acids, sterols and alcohol data provided a classification of SIO samples, by an efficient k-means clustering algorithm analysis. The ANOVA found significant differences between clusters for palmitic acid, oleic acid, γ-tocopherol, δ-tocopherol, campesterol and stigmasterol; these compounds could be used as markers of authenticity in commercial Sacha inchi oils.
PubMed: 31686682
DOI: 10.1007/s13197-019-03938-9 -
Plant Physiology Nov 2019Tocopherols are lipid-soluble antioxidants synthesized in plastids of plants and other photosynthetic organisms. The four known tocopherols, α-, β-, γ-, and...
Tocopherols are lipid-soluble antioxidants synthesized in plastids of plants and other photosynthetic organisms. The four known tocopherols, α-, β-, γ-, and δ-tocopherol, differ in number and position of methyl groups on their chromanol head group. In unstressed Arabidopsis () leaves, α-tocopherol constitutes the main tocopherol form, whereas seeds predominantly contain γ-tocopherol. Here, we show that inoculation of Arabidopsis leaves with the bacterial pathogen induces the expression of genes involved in early steps of tocopherol biosynthesis and triggers strong accumulation of γ-tocopherol, moderate production of δ-tocopherol, and generation of the benzoquinol precursors of tocopherols. The pathogen-inducible biosynthesis of tocopherols is promoted by the immune regulators ENHANCED DISEASE SUSCEPTIBILITY1 and PHYTOALEXIN-DEFICIENT4. In addition, tocopherols accumulate in response to bacterial flagellin and reactive oxygen species. By quantifying tocopherol forms in inoculated wild-type plants and biosynthetic pathway mutants, we provide biochemical insights into the pathogen-inducible tocopherol pathway. Notably, () mutant plants, which are compromised in both tocopherol and benzoquinol precursor accumulation, exhibit increased susceptibility toward compatible and possess heightened levels of markers of lipid peroxidation after bacterial infection. The deficiency of triunsaturated fatty acids in () quadruple mutants prevents increased lipid peroxidation in the background and restores pathogen resistance to wild-type levels. Therefore, the tocopherol biosynthetic pathway positively influences salicylic acid accumulation and guarantees effective basal resistance of Arabidopsis against compatible , possibly by protecting leaves from the pathogen-induced oxidation of trienoic fatty acid-containing lipids.
Topics: Arabidopsis; Arabidopsis Proteins; Carboxylic Ester Hydrolases; DNA-Binding Proteins; Gene Expression Regulation, Plant; Plant Immunity; Plant Leaves; Pseudomonas syringae; Tocopherols
PubMed: 31515446
DOI: 10.1104/pp.19.00618 -
The Journal of Nutrition Feb 2020Vitamin E α-, γ-, or δ-tocopherol (αT, γT, δT) and γ- or δ-tocotrienol (γTE, δTE) are metabolized to hydroxychromanols and carboxychromanols including...
BACKGROUND
Vitamin E α-, γ-, or δ-tocopherol (αT, γT, δT) and γ- or δ-tocotrienol (γTE, δTE) are metabolized to hydroxychromanols and carboxychromanols including 13'-carboxychromanol (13'-COOH), 11'-COOH, and carboxyethyl hydroxychroman (CEHC), some of which have unique bioactivities compared with the vitamers. However, the bioavailability of these metabolites has not been well characterized.
OBJECTIVE
We investigated the pharmacokinetics (PK) of vitamin E forms and metabolites in rats.
METHODS
Six-week-old male Wistar rats received 1-time gavage of γT-rich tocopherols (50 mg/kg) containing γT/δT/αT (57.7%, 21.9%, and 10.9%, respectively) or δTE-rich tocotrienols (35 mg/kg) containing δTE/γTE (8:1). We quantified the time course of vitamin E forms and metabolites in the plasma and their 24-h excretion to the urine and feces. The general linear model repeated measure was used for analyses of the PK data.
RESULTS
In the rats' plasma, Cmax of γT or δTE was 25.6 ± 9.1 μM (Tmax = 4 h) or 16.0 ± 2.3 μM (Tmax = 2 h), respectively, and sulfated CEHCs and sulfated 11'-COOHs were the predominant metabolites with Cmax of 0.4-0.5 μM (Tmax ∼5-7 h) or ∼0.3 μM (Tmax at 4.7 h), respectively. In 24-h urine, 2.7% of γT and 0.7% of δTE were excreted as conjugated CEHCs. In the feces, 17-45% of supplemented vitamers were excreted as unmetabolized forms and 4.9-9.2% as unconjugated carboxychromanols, among which 13'-COOHs constituted ∼50% of total metabolites and the amount of δTE-derived 13'-COOHs was double that of 13'-COOH derived from γT.
CONCLUSIONS
PK data of vitamin E forms in rats reveal that γT, δT, γTE, and δTE are bioavailable in the plasma and are mainly excreted as unmetabolized forms and long-chain metabolites including 13'-COOHs in feces, with more metabolites from tocotrienols than from tocopherols.
Topics: Animals; Biological Availability; Chromans; Feces; Male; Rats; Rats, Wistar; Tocopherols; Tocotrienols
PubMed: 31495894
DOI: 10.1093/jn/nxz217 -
Molecules (Basel, Switzerland) Aug 2019Plants and animals are sources of various bioactive compounds that exhibit a broad spectrum of health-promoting effects. Scientists continue studies on the chemical...
Plants and animals are sources of various bioactive compounds that exhibit a broad spectrum of health-promoting effects. Scientists continue studies on the chemical composition of many products in search of foods with high nutritional value. The pumpkin ( sp.) is unquestionably a source of valuable nutrients. This vegetable is well-known all over the world and it is appreciated due to its high content of carotenoids, but it is still not much used in the processing industry. The aim of present study was to compare the flesh of 15 pumpkin varieties belonging to the and species in terms of the bioactive compound content (carotenoids, phenolic acids, flavonols, minerals and vitamins) and to demonstrate whether the variety has an effect on the chemical composition. To date, no such extensive research has been carried out in this area. The research revealed that the pumpkin pulp had high content of carotenoids. In nearly all cases lutein was the most abundant carotenoid. Numerous phenolic acids and flavonols were also identified. All the cultivars contained gallic acid, protocatechuic acid, 4-hydroxybenzoic acid, vanillic acid, chlorogenic acid, caffeic acid, and rutin. The pumpkin pulp also contained alpha- and gamma-tocopherol. No beta- or delta-tocopherol was found. Potassium, calcium, and sodium were the most abundant minerals. The research also proved that the profile of bioactive compounds in the pumpkin pulp was considerably diversified and depended on the species and cultivar.
Topics: Antioxidants; Carotenoids; Chromatography, High Pressure Liquid; Cluster Analysis; Cucurbita; Metabolome; Metabolomics; Minerals; Nutritive Value; Phytochemicals; Plant Extracts; Polyphenols; Secondary Metabolism
PubMed: 31416184
DOI: 10.3390/molecules24162945