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Journal of Oleo Science 2021The tocopherol contents of unripe and ripe avocado fruit oil extracted from Pinkerton, Hass and Fuerte varieties were determined after drying fruit using air, microwave...
The tocopherol contents of unripe and ripe avocado fruit oil extracted from Pinkerton, Hass and Fuerte varieties were determined after drying fruit using air, microwave or oven drying methods. The α-tocopherol content changed between 13.70 mg/100 g (microwave-dried) and 28.06 mg/100 g (air-dried) in oil from unripe Pinkerton fruit; between 14.86 mg/100 g (microwave-dried) and 88.12 mg/100 g (fresh) in oil from unripe Hass fruit and between 13.31 mg/100 g (microwave-dried) and 17.35 mg/100 g (oven-dried) in oil from unripe Fuerte fruit. The α-tocopherol contents in oil from ripe Fuerte fruit changed between 13.21 mg/100 g (fresh) and 17.61 mg/100 g (oven-dried). In addition, γ-tocopherol contents varied between 11.55 mg/100 g (air-dried) and 14.61 mg/100 g (microwave-dried) unripe "Pinkerton" fruit; between 11.52 mg/100 g (air-dried) and 15.01 mg/100 g (fresh) in unripe Hass fruit and between 12.17 mg/100 g (air-dried) and 15.27 mg/100 g (microwave-dried) unripe Fuerte fruit. The γ-tocopherol contents ranged from 12.71 mg/100 g (fresh) to 17.40 mg/100 g (oven-dried) in ripe Hass fruit; from 10.29 mg/100 g (fresh) and 17.20 mg/100 g (microwave-dried) ripe Fuerte fruit. α-, β-, γ- and δ-tocopherols could not be detected in ripe fresh Pinkerton fruit. In general, β- and δ-tocopherol could not be detected in most of the unripe and ripe avocado fruit oils. α-Tocopherol and γ-tocopherol contents of dried ripe Fuerte fruit oils were found to be higher compared to those of dried unripe Fuerte fruits.
Topics: Chromatography, High Pressure Liquid; Desiccation; Fruit; Microwaves; Persea; Plant Oils; Plant Physiological Phenomena; Tocopherols
PubMed: 33431769
DOI: 10.5650/jos.ess20230 -
Food Technology and Biotechnology Sep 2020Utilization of wheat germ and wheat germ oil is limited due to high enzymatic activity and the presence of unsaturated fatty acids, which require stabilization...
RESEARCH BACKGROUND
Utilization of wheat germ and wheat germ oil is limited due to high enzymatic activity and the presence of unsaturated fatty acids, which require stabilization techniques to overcome this problem.
EXPERIMENTAL APPROACH
In this study, the effects of stabilization methods (dry convective oven heating at 90 and 160 °C, microwave radiation at 180 and 360 W, and autoclave steaming) on both wheat germ and its oil were evaluated.
RESULTS AND CONCLUSIONS
Steaming caused the most dramatic changes in lipoxygenase activity, free fatty acid content, DPPH radical scavenging activity, and mass fractions of tocopherols and tocotrienols. Lower peroxide values were measured in the oil samples treated with convectional heating (160 °C) and steaming at temperatures above 100 °C. However, -anisidine values of samples treated at higher temperatures were considerably greater than those of samples stabilized at lower temperatures. Oven heating at 160 °C was also one of the most effective treatments, after steaming, for the inactivation of lipoxygenase. Steaming significantly reduced mass fraction of total tocopherols, which was directly associated with the greater loss of β-tocopherol content. On the contrary, γ- and δ-tocopherol and tocotrienol homologues were abundant with higher amounts in steamed samples. α-Tocopherol and γ-tocotrienol were the most resistant isomers to stabilization processes.
NOVELTY AND SCIENTIFIC CONTRIBUTION
This study shows that the high temperature oven heating method, which is widely used in the industry for thermal stabilization of wheat germ, does not provide an advantage in oxidative stability compared to steaming and microwave applications. Steaming delayed oxidation in the germ, while further inhibiting lipoxygenase activity. Moreover, tocotrienols were more conservable. In industrial application, low-power microwave (180 instead of 360 W) and oven heating at lower temperature (90 instead of 160 °C) would be preferable.
PubMed: 33281490
DOI: 10.17113/ftb.58.03.20.6638 -
Nature Communications Jun 2018From life science to material science, to pharmaceutical industry, and to food chemistry, polysulfides are vital structural scaffolds. However, there are limited...
From life science to material science, to pharmaceutical industry, and to food chemistry, polysulfides are vital structural scaffolds. However, there are limited synthetic methods for unsymmetrical polysulfides. Conventional strategies entail two pre-sulfurated cross-coupling substrates, R-S, with higher chances of side reactions due to the characteristic of sulfur. Herein, a library of broad-spectrum polysulfurating reagents, R-S-S-OMe, are designed and scalably synthesized, to which the R-S-S source can be directly introduced for late-stage modifications of biomolecules, natural products, and pharmaceuticals. Based on the hard and soft acids and bases principle, selective activation of sulfur-oxygen bond has been accomplished via utilizing proton and boride for efficient unsymmetrical polysulfuration. These polysulfurating reagents are highlighted with their outstanding multifunctional gram-scale transformations with various nucleophiles under mild conditions. A diversity of polysulfurated biomolecules, such as SS-(+)-δ-tocopherol, SS-sulfanilamide, SS-saccharides, SS-amino acids, and SSS-oligopeptides have been established for drug discovery and development.
PubMed: 29875443
DOI: 10.1038/s41467-018-04306-5 -
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 -
Food Chemistry Mar 2021Sacha inchi (Plukenetia volubilis) oil (SI) is appreciated for its nutritional and sensorial characteristics. The aim of this study was to evaluate SI changes during...
Sacha inchi (Plukenetia volubilis) oil (SI) is appreciated for its nutritional and sensorial characteristics. The aim of this study was to evaluate SI changes during French fries deep-frying at 170 °C or 180 °C up to 119 and 50 min, respectively; commercial soybean oil (SO) was tested as control. SI had high α-linolenic acid (53.8%), linoleic acid (33.4%) and total tocopherols (2540.1 mg/kg). During frying tocopherol content, oil stability and antioxidant capacity (ABTS, DPPH) decreased following zero-order kinetics; γ-tocopherol showed the strongest decrease. Notwithstanding the high SI unsaturation and the commercial antioxidant (TBHQ) in SO, SI showed slightly higher or similar hydrolysis (free fatty acids and diacylglycerols), similar primary (K, oxidized-triacylglycerols) and lower secondary (K, triacylglycerol oligopolymers) oxidation. Because of the high tocopherol content, SI showed lower degradation than SO. Thus, SI is suitable for short-term deep-frying; additionally, it may enhance the nutritional value and the flavour of fried foods.
Topics: Antioxidants; Cooking; Euphorbiaceae; Fatty Acids; Oxidation-Reduction; Plant Oils; Tocopherols
PubMed: 32890859
DOI: 10.1016/j.foodchem.2020.127942 -
The Journal of Nutrition, Health & Aging 2013To determine the effects of vitamins and carotenoids on brain white matter lesions (WMLs), we examined the associations between WMLs with vitamin and carotenoid levels...
PURPOSE
To determine the effects of vitamins and carotenoids on brain white matter lesions (WMLs), we examined the associations between WMLs with vitamin and carotenoid levels in Japanese middle-aged and elderly subjects.
SUBJECTS AND METHODS
Four-hundred and sixty-nine healthy participants (male = 317; female = 152) that underwent medical examinations were examined. Deep white matter lesions (DWLs) were detected via magnetic resonance imaging (MRI) in 39 subjects. We evaluated the effects of vitamin and carotenoid levels on DWLs via logistic regression analysis.
RESULTS
Lower gamma-tocopherol levels were significantly associated with DWLs in all subjects. While lower gamma-tocopherol and vitamin C levels were significantly associated with DWLs in males, lower delta-tocopherol levels were associated with DWLs in females. The associations between DWLs and lower gamma- and delta-tocopherol and vitamin C levels were independent of age, hypertension, or smoking. However, the associations between DWLs and lower alfa-tocopherol were not significant following adjustments for smoking.
CONCLUSION
Lower carotenoid and vitamin levels were independently associated with cerebral DWLs in Japanese subjects.
Topics: Aged; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Brain; Brain Diseases; Carotenoids; Deficiency Diseases; Female; Geriatric Assessment; Humans; Japan; Male; Middle Aged; Nutrition Assessment; Nutritional Status; Sex Factors; Tocopherols; Vitamin E Deficiency; Vitamins
PubMed: 23636547
DOI: 10.1007/s12603-012-0419-z -
The Journal of Nutritional Biochemistry Feb 2022Cyclooxygenase (COX-1 and COX-2)- and 5-lipoxygenase (5-LOX)-catalyzed biosynthesis of eicosanoids play important roles in inflammation and chronic diseases. The vitamin...
Different forms of vitamin E and metabolite 13'-carboxychromanols inhibit cyclooxygenase-1 and its catalyzed thromboxane in platelets, and tocotrienols and 13'-carboxychromanols are competitive inhibitors of 5-lipoxygenase.
Cyclooxygenase (COX-1 and COX-2)- and 5-lipoxygenase (5-LOX)-catalyzed biosynthesis of eicosanoids play important roles in inflammation and chronic diseases. The vitamin E family has four tocopherols and tocotrienols. We have shown that the metabolites of δ-tocopherol (δT) and δ-tocotrienol (δTE), i.e., δT-13'-carboxychromanol (COOH) and δTE-13'-COOH, respectively, inhibit COX-1/-2 and 5-LOX activity, but the nature of how they inhibit 5-LOX is not clear. Further, the impact of tocopherols and tocotrienols on COX-1/-2 or 5-LOX activity has not been fully delineated. In this study, we found that tocopherols and tocotrienols inhibited human recombinant COX-1 with IC50s of 1-12 µM, and suppressed COX-1-mediated formation of thromboxane in collagen-stimulated rat's platelets with IC50s of 8-50 µM. None of the vitamin E forms directly inhibited COX-2 activity. 13'-COOHs inhibited COX-1 and COX-2 enzyme activity with IC50s of 3-4 and 4-10 µM, respectively, blocked thromboxane formation in collagen- and ionophore-stimulated rats' platelets with IC50s of 1.5-2.5 µM, and also inhibited COX-2-mediated prostaglandins in stimulated cells. Using enzyme kinetics, we observed that δT-13'-COOH, δTE-13'-COOH and δTE competitively inhibited 5-LOX activity with Ki of 1.6, 0.8 and 2.2 µM, respectively. These compounds decreased leukotriene B from stimulated neutrophil-like cells without affecting translocation of 5-LOX from cytosol to the nucleus. Our study reveals inhibitory effects of vitamin E forms and 13'-COOHs on COX-1 activity and thromboxane formation in platelets, and elucidates mechanisms underlying their inhibition of 5-LOX. These observations are useful for understanding the role of these compounds in disease prevention and therapy.
Topics: A549 Cells; Animals; Arachidonate 5-Lipoxygenase; Benzopyrans; Blood Platelets; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Fatty Acids; Humans; Lipoxygenase Inhibitors; Mice; RAW 264.7 Cells; Thromboxanes; Tocopherols; Tocotrienols; Vitamin E; Vitamins
PubMed: 34710615
DOI: 10.1016/j.jnutbio.2021.108884 -
Proceedings of the National Academy of... Apr 2018Bietti's crystalline dystrophy (BCD) is an intractable and progressive chorioretinal degenerative disease caused by mutations in the gene, resulting in blindness in...
Bietti's crystalline dystrophy (BCD) is an intractable and progressive chorioretinal degenerative disease caused by mutations in the gene, resulting in blindness in most patients. Although we and others have shown that retinal pigment epithelium (RPE) cells are primarily impaired in patients with BCD, the underlying mechanisms of RPE cell damage are still unclear because we lack access to appropriate disease models and to lesion-affected cells from patients with BCD. Here, we generated human RPE cells from induced pluripotent stem cells (iPSCs) derived from patients with BCD carrying a mutation and successfully established an in vitro model of BCD, i.e., BCD patient-specific iPSC-RPE cells. In this model, RPE cells showed degenerative changes of vacuolated cytoplasm similar to those in postmortem specimens from patients with BCD. BCD iPSC-RPE cells exhibited lysosomal dysfunction and impairment of autophagy flux, followed by cell death. Lipidomic analyses revealed the accumulation of glucosylceramide and free cholesterol in BCD-affected cells. Notably, we found that reducing free cholesterol by cyclodextrins or δ-tocopherol in RPE cells rescued BCD phenotypes, whereas glucosylceramide reduction did not affect the BCD phenotype. Our data provide evidence that reducing intracellular free cholesterol may have therapeutic efficacy in patients with BCD.
Topics: Animals; Cholesterol; Corneal Dystrophies, Hereditary; Cytochrome P450 Family 4; Humans; Mice; Mutation; Phenotype; Retinal Diseases; Retinal Pigment Epithelium
PubMed: 29581279
DOI: 10.1073/pnas.1717338115 -
Experimental Cell Research Oct 2021Mucopolysaccharidosis type IIIB (MPS IIIB) is a lysosomal disease caused by mutations in the NAGLU gene encoding α-N-acetylglucosaminidase (NAGLU) which degrades...
Mucopolysaccharidosis type IIIB (MPS IIIB) is a lysosomal disease caused by mutations in the NAGLU gene encoding α-N-acetylglucosaminidase (NAGLU) which degrades heparan sulfate in lysosomes. Deficiency in NAGLU results in lysosomal accumulation of glycosaminoglycans (GAGs) and neurological symptoms. Currently, there is no effective treatment or cure for this disease. In this study, induced pluripotent stem cell lines were established from two MPS IIIB patient fibroblast lines and differentiated into neural stem cells and neurons. MPS IIIB neural stem cells exhibited NAGLU deficiency accompanied with GAG accumulation, as well as lysosomal enlargement and secondary lipid accumulation. Treatments with recombinant NAGLU, δ-tocopherol, and 2-hydroxypropyl-b-cyclodextrin significantly reduced the disease phenotypes in these cells. These results indicate the MPS IIIB neural stem cells and neurons have the disease relevant phenotype and can be used as a cell-based disease model system for evaluation of drug efficacy and compound screening for drug development.
Topics: Acetylglucosaminidase; Cell Differentiation; Heparitin Sulfate; Humans; Induced Pluripotent Stem Cells; Lysosomes; Mucopolysaccharidosis III; Neural Stem Cells; Neurons; Phenotype
PubMed: 34411609
DOI: 10.1016/j.yexcr.2021.112785 -
The Journal of Nutrition Jan 2018Few studies have previously assessed how pre-existing vitamin E status is associated with risk of tuberculosis (TB) disease progression.
BACKGROUND
Few studies have previously assessed how pre-existing vitamin E status is associated with risk of tuberculosis (TB) disease progression.
OBJECTIVE
We evaluated the association between baseline plasma concentrations of 3 vitamin E isomers (α-tocopherol, γ-tocopherol, and δ-tocopherol) and TB disease risk.
METHODS
We conducted a case-control study nested within a longitudinal cohort of household contacts (HHCs) of pulmonary TB cases in Lima, Peru. We defined cases as HHCs who developed active TB disease ≥15 d after the diagnosis of the index patient, and we matched each case to 4 control cases who did not develop active TB based on age by year and gender. We used univariate and multivariate conditional logistic regression to calculate ORs for incident TB disease by plasma concentrations of α-tocopherol, γ-tocopherol, and δ-tocopherol.
RESULTS
Among 6751 HIV-negative HHCs who provided baseline blood samples, 180 developed secondary TB during follow-up. After controlling for possible confounders, we found that baseline α-tocopherol deficiency conferred increased risk of incident TB disease (adjusted OR: 1.59; 95% CI: 1.02, 2.50; P = 0.04). Household contacts in the lowest tertile of δ-tocopherol were also at increased risk of progression to TB disease compared to those in the highest tertile (tertile 1 compared with tertile 3, adjusted OR: 2.29; 95% CI: 1.29, 4.09; P-trend = 0.005). We found no association between baseline concentration of γ-tocopherol and incident TB disease.
CONCLUSIONS
Vitamin E deficiency was associated with an increased risk of progression to TB disease among HHCs of index TB cases. Assessment of vitamin E status among individuals at high risk for TB disease may play a role in TB control efforts.
Topics: Adolescent; Adult; Case-Control Studies; Child; Disease Progression; Family Characteristics; Female; Humans; Incidence; Logistic Models; Male; Peru; Risk Factors; Socioeconomic Factors; Tuberculosis, Pulmonary; Vitamin E; Vitamin E Deficiency; Young Adult
PubMed: 29378042
DOI: 10.1093/jn/nxx006