VITAMIN E DISSOLUTION IN SULFOBETAINE ZW1TTERIONIC SURFACTANT SOLUTION AND ENHANCEMENT OF DIS SOLUTION BY ADDING SODIUM CHLORIDE

Vitamin E is widely used in pharmaceutical, food and cosmetic preparations.This paper discusses methods of preparing vitamin E emulsions by using sulfobetaine (SB) zwitterionic surfactants which have high electrolyte tolerance. The amount of vitamin E dissolved in water was analyzed by turbidity and UV absorption measurements. The emulsion droplet size was determined by laser light scattering. Microemulsions with small particle size and high resistance to oxidation in air can be obtained by solubilizing vitamin E in SB solutions at high concentrations (above %) The performance of a series of SB surfactants is compared in 1.5% solutions. A SB surfactant with a 12 carbon chain seems to be the most effective in dissolving vitamin E. The saturation value of vitamin E is increased about one order of magnitude by adding NaCl to the SB surfactant solutions. Emulsions formed in surfactant solutions containing NaCl (0 4-0.6 M) are stable at low surfactant concentrations such as 0.2-0.4 % The emulsion droplet sizes are below or around 200nm.     

Size and charge characterization of polymeric drug delivery systems by Taylor dispersion analysis and capillary electrophoresis

In this work, Taylor dispersion analysis and capillary electrophoresis were used to characterize the size and charge of polymeric drug delivery nanogels based on polyglutamate chains grafted with hydrophobic groups of vitamin E. The hydrophobic vitamin E groups self-associate in water to form small hydrophobic nanodomains that can incorporate small drugs or therapeutic proteins. Taylor dispersion analysis is well suited to determine the weight average hydrodynamic radius of nanomaterials and to get information on the size polydispersity of polymeric samples. The effective charge was determined either from electrophoretic mobility and hydrodynamic radius using electrophoretic modeling (three different approaches were compared), or by indirect UV detection in capillary electrophoresis. The influence of vitamin E hydrophobicity on the polymer effective charge has been studied. The presence of vitamin E leads to a drastic decrease in polymer effective charge in comparison to non-modified polyglutamate. Finally, the electrophoretic behavior of polyglutamate backbone grafted with hydrophobic vitamin E (pGVE) nanogels according to the ionic strength was investigated using the recently proposed slope plot approach. It was deduced that the pGVE nanogels behave electrophoretically as polyelectrolytes which is in good agreement with the high water content of the nanogels.

高硒及高硒高维生素E合用对十二月龄大鼠血清MDA和ALT的影响

给动物喂食高Se、高vitaminE、高Se高vitaminE合用饲料 ,探讨单独及合用高Se、高vitaminE对十二月龄动物血清中MDA和ALT的影响。结果显示 ,与对照组比较 ,单独及合用高Se、高vitaminE均可显著降低血清中MDA的含量 (P <0 0 1 ) ,高vitaminE尚能使血清中ALT水平升高 (P <0 0 5 ) ,而高Se高vitaminE合用则可纠正高vitaminE引起的血清中ALT水平的升高     

高硒情况下维生素E对幼龄大鼠抗氧化作用的研究

研究了高Se或高维生系E下,幼龄大鼠体内抗氧化活性的变化以及高Se下,维生素E对其体内抗氧化水平的影响。将三月龄Wistar大鼠32只随机分成4组：正常饲料组、高Se高维生素E饲料组、高Se饲料组和高维生素E饲料组。饲至十周末,处死大鼠,按试剂盒要求分别取其血液、心、肝、肾制成标本测SOD、CAT活性及MDA、GSH含量。结果表明,高Se或高维生素E下饲养下的大鼠与对照组比较,血液中SOD活性明显下降;维生素E能明显抑制高Se大鼠血液中SOD活性的下降。结论：单独高Se或高维生素E会降低幼龄大鼠的抗氧化活性,而维生素E能明显提高高Se下幼龄大鼠体内抗氧化活性。     

高硒情况下维生素E对老龄大鼠血清中抗氧化作用的影响

研究了高Se或高维生素E下，老龄大鼠体内抗氧化活性的变化以及高Se下维生素E对其体内抗氧化水平的影响。将十二月龄Wistar大鼠32只随机分成4组：（1）正常饲料组；（2）高Se饲料组；（3）高维生素E饲料组；（4）高Se高维生素E饲料组。饲至十周末，处死大鼠，按试剂盒要求取其血液制成血清测GSH－Px,SOD活性，MDA含量。结果表明，高Se或高维生素E下饲养下的大鼠与对照组比较，血清中GSH－Px活性升高（P＜0．05）。SOD活性未见改变，MDA含量分别减少50％和56％，有显著差异（P＜0．01）；维生素E与高Se合用与高Se组比较能进一步同GSH－Px,SOD活性（P＜0．01）。结论：高Se会升高老龄大鼠的抗氧化活性，而与维生素E合用更加升高老龄大鼠血液中抗氧化活性。     

A CIDEP and fluorescence study of the oxidation of vitamin E: The vitamin E radical cation

The photochemical and thermal oxidations of vitamin E in trifluoroacetic acid were investigated by the combination of electron spin resonance, chemically induced dynamic electron polarization, and fluorescence techniques. Two independent thermal pathways led to the formation of the vitamin E radical cation in which one of the paths involved the intermediate neutral semiquinone radical. Photo-oxidation, however, did not involve the neutral radicals. The fluorescence spectra of both the neutral and the charged forms of the vitamin E radicals are reported here for the first time. Some model charge transfer reactions involving the vitamin E radical cation were reported.     

Transport of topical anesthetics in vitamin E loaded silicone hydrogel contact lenses

Transport of surface active anesthetic drugs through silicone hydrogel contact lenses containing nanosized vitamin E aggregates is explored for achieving extended anesthetics delivery. Commercial silicone hydrogel contact lenses release most ophthalmic drugs including local anesthetics for only a few hours, which is not adequate. Here we focus on creating dispersion of highly hydrophobic vitamin E aggregates in the lenses as barriers for drug diffusion for increasing the release durations. This approach has been shown previously to be successful in extending the release durations for some common hydrophilic ophthalmic drugs. The topical anesthetic drugs considered here (lidocaine, bupivacaine, and tetracaine) are hydrophilic at physiologic pH due to the charge, and so these cannot partition into the vitamin E barriers. However, these surface active drug molecules adsorb on the surface of the vitamin E barriers and diffuse along the surface, leading to only a small decrease in the effective diffusivity compared to non-surface-active hydrophilic drugs. The drug adsorption can be described by the Langmuir isotherm, and measurements of surface coverage of the drugs on the vitamin E provide an estimate of the available surface area of vitamin E, which can then be utilized to estimate the size of the aggregates. A diffusion controlled transport model that includes surface diffusion along the vitamin E aggregates and diffusion in the gel fit the transport data well. In conclusion, the vitamin E loaded silicone contact lens can provide continuous anesthetics release for about 1-7 days, depending on the method of drug loading in the lenses, and thus could be very useful for postoperative pain control after corneal surgery such as the photorefractive keratectomy (PRK) procedure for vision correction.     

Measurements of the major isoforms of vitamins A and E and carotenoids in the blood of people with spinal-cord injuries

We used reversed-phase HPLC with diode array detection to simultaneously measure the major isoforms of vitamins A, E, and the carotenoids in serum from 55 healthy people with spinal cord injuries. Typically, the method measured retinol (vitamin A), alpha-tocopherol (vitamin E) and beta-carotene, alpha-carotene, lutein, lycopene, and cryptoxanthin (carotenoids). gamma-Tocopherol (vitamin E), 25-hydroxycalciferol (vitamin D), and the carotenoid zeaxanthin could also be measured when they were present in high concentrations. Healthy people with spinal cord injuries were more likely than similar people without injuries to have low concentrations of alpha-tocopherol, and to a lesser extent retinol and beta-carotene.     

Determination of vitamin E and carotenoid pigments by high performance liquid chromatography in shell of Chionoecetes opilio

This study reports the optimization of a method for the determination of vitamin E and carotenoids in shells of Chionoecetes opilio samples by online HPLC coupled with UV-vis and fluorescence detectors. The carotenoids were determined with diode-array detector (lambda 450 nm) and vitamin E with fluorescence detection (lambda(ex) 288, lambda(em) 331 nm). Two extractions methods were compared, saponification followed by an extraction step and a simple extraction with acetone. The last one was selected because allows to determine all compounds. Linearity, precisions and recoveries achieved for all compounds were satisfactory. Mean concentrations (mg per 100 g dry weight) were; 23.3 for vitamin E, 9.49 for astaxanthin and 0.2 mg for beta-carotene.     

Rapid dissolution of vitamin E by using sodium N-lauroylsarcosinate ionic surfactant

Vitamin E is widely used in pharmaceutical, food and cosmetic preparations. This paper discusses methods of preparing a vitamin E emulsion by using sodium N-lauroylsarcosinate (SNLS) ionic surfactant. The amount of vitamin E dissolved in water was analyzed by turbidity and UV absorption measurements. The emulsion droplet size was determined by laser light scattering. Microemulsions with small particle size and high resistance to oxidation in air can be obtained by solubilizing vitamin E in SNLS solution. The dissolution is rapid and the surfactant solution has high solubilization power. At 0.7% surfactant concentration, the saturation value is 1 g vitamin E per gram of surfactant. The micellar dissociation concentration (MDC) of the surfactant can be estimated from a vitamin saturation—surfactant concentration curve. Dissolution mechanisms at different surfactant concentrations are interpreted by use of the MDC and CMC (critical micellar concentration) concepts.     

Antioxidant vitamins and their use in preventing cardiovascular disease

Atherosclerosis remains one of the leading causes of death in Western populations. Subsequent to the discovery that oxidative stress plays a pivotal role in the development and progression of atherosclerosis, vitamins C and E, along with other antioxidants, were studied as potential therapies for the disease. However, while in vitro and in vivo studies showed promising antiatherogenic effects for vitamins C and E, clinical trials in which patients were given high doses of vitamin E or C showed no benefit and even possible harm. This review will attempt to summarize the known mechanistic data regarding the biochemical effects of vitamins C and E and their relevance to atherosclerosis, and offer an explanation for the failure of clinical trials to show that supplementation with these vitamins provides any benefit when given indiscriminately. We provide one example of how pharmacogenomics may be used to identify a sub-population which may indeed benefit from antioxidant supplementation.     

Countercurrent chromatography separation of vitamin E isomers in a co-current mode

Vitamin E represents a group of lipophilic phenolic compounds, including α-tocopherol, β-tocopherol, γ-tocopherol, and δ-tocopherol, and α-tocotrienol, β-tocotrienol, γ-tocotrienol, and δ-tocotrienol isomers. Different forms of vitamin E have been proven to exhibit varying biological activities. However, due to their structural similarities, the separation of vitamin E isomers is a challenging task. Therefore, it is crucial to establish an efficient method for isolating individual isomers. In this study, co-current countercurrent chromatography was employed to isolate vitamin E isomers from commercial capsules using a n-heptane-methanol-water (10:9.5:0.5, v/v) solvent system. The partition coefficients of the main constituents in the capsules ranged from 0.94 to 6.23, requiring over 450 min for a complete separation. To improve separation efficiency, a co-current elution mode was implemented and the flow rates of the two liquid phases as well as sample amount were examined. The results suggested that increasing the flow rate of the stationary phase and sample size could result in more effective separation, shorter separation time, and higher yield. It proved that co-current countercurrent chromatography was an effective method for the separation of vitamin E isomers.     

Surface modification of poly(lactide-co-glycolide) nanoparticles by d-α-tocopheryl polyethylene glycol 1000 succinate as potential carrier for the delivery of drugs to the brain

The potential health benefits of vitamin E (d-α-tocopheryl polyethylene glycol 1000 succinate, TPGS), particularly, in curing of the neurological symptoms associated with vitamin E deficiency have been reported. Hence, vitamin E containing carriers for delivery of drugs to the brain might be useful from different points of view. Herein, in order to obtain desired surface morphology and particle size of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) and high emulsifying effects, TPGS-modified PLGA NPs were optimized as a potential carrier for the delivery of drugs to the brain. The particle sizes, surface morphology, phase composition correlated with different emulsifiers and different stirring times were characterized. Also, the in vitro cytotoxicity of the samples using PC12 cell line was investigated. According to the obtained results, by increasing the percentages of TPGS, the average particle size decreased and the distribution of particle diameters came closer by further addition, and the larger particles did not create. In addition, no obvious cytotoxicity was observed at various TPGS amounts, and the modified PLGA NPs were considered biocompatible since they show little decrease in cellular viability. With the increase of TPGS ratio, more effective in vitro therapeutic effects could be observed, which achieved the highest cell viability, because the degradation of NPs may release the most amounts of TPGS components that have synergistic activity. Furthermore, it was found that TPGS as a water-soluble derivative of natural source of vitamin E could be a perfect emulsifier for making PLGA NPs as potential carrier for delivery of drugs to the brain.     

An electrophoretic study of vitamin E status and expression of heat shock proteins in alveolar type II and liver cells

Vitamin E is the most important lipophilic antioxidant. Oxidative injuries are prevented or minimized by vitamin E supplementation. Various physiological and pathological situations are accompanied by vitamin E deficiency. However, it is not clear whether alimentary vitamin E deficiency in itself constitutes oxidant stress that induces appropriate responses, which, in turn, can be avoided by adequate vitamin E supplies, or whether the remaining cellular antioxidants compensate a temporary vitamin E deficiency. We studied effects of the dietary vitamin E status on cellular vitamin E levels and on the expression of heat shock proteins (HSPs) in alveolar type II cells and liver. The expression of HSPs, representing an early and very sensitive marker of cellular stress, was compared with the activity of antioxidative enzymes. Vitamin E depletion caused a substantial increase in HSP32 in alveolar type II cells, whereas in liver there was a marked increase in HSP70. The activity of the antioxidant enzymes, however, did not change significantly. A reversal of HSP expression to almost normal levels was seen after vitamin E resupplementation. These results indicate that, under normal conditions, a suboptimal supply of vitamin E to rats exposes the alveolar type II cells and the liver to reversible cellular stress.     

天然维生素E制品中杂质的分离与鉴定

利用高效液相色谱、气相色谱-质谱联用与高分辨质谱对天然维生素E制品中的杂质进行了分离分析与结构鉴定。采用正相高效液相色谱法分离天然维生素E的4种异构体及2种杂质,并对杂质馏分进行富集纯化。将气相色谱-质谱联用与高分辨质谱检测相结合,用于获得杂质的结构信息。通过比较杂质精确相对分子质量和解析质谱碎片离子,推断杂质为芝麻素及其同分异构体表芝麻素。经与芝麻素对照品保留时间及碎片离子数据比对,确证了对杂质结构的推断。所建立的杂质鉴定方法快捷、有效,可应用于天然维生素E制品的食品安全控制。     

正相高效液相色谱法测定食物中8种维生素E异构体及维生素A

建立了正相高效液相色谱测定食物中8种维生素E异构体及维生素A的方法。样品中的维生素E异构体和维生素A经皂化和液液萃取,Waters ACQUITY^TM UPLC BEH Amide色谱柱(150 mm×3.0 mm, 1.7 μm)分离,体积比为90 : 10的正己烷与叔丁基甲基醚-四氢呋喃-甲醇(20:10:1, v/v/v)为流动相,荧光检测器和紫外检测器串联检测。4种生育酚在5.0~60.0 mg/L(r²≥0.9999)、维生素A和4种三烯生育酚在0.5~6.0 mg/L(r²≥0.9996)范围内具有良好的线性,各基质中目标物的检出限在20~60 μg/kg之间;9个组分在各基质中的加标回收率为79.2%~114.2%,相对标准偏差(RSD)为1%~12%。该方法简便、灵敏、可靠、环保,可用于食物中8种维生素E异构体以及维生素A含量的同时测定。     

天然维生素E分析的样品前处理方法研究新进展

维生素E是一种天然抗氧化剂,有重要的生理功能,其含量的分析检测至关重要。样品前处理在维生素E的分析检测过程中耗时最长,作用也最重要,并在一定程度上决定了样品中天然维生素E分析过程的效率和分析结果的信度。近年来,该领域的研究人员在样品前处理方面做了大量工作,开发出众多简捷、高效、可靠的维生素E提取方法。该文综述了皂化法、溶剂提取法、加压溶剂提取法、超临界流体萃取法和固相萃取法等近年发展起来的天然维生素E提取方法,介绍和评述了其应用及优缺点,并提出了发展方向。     

Determination of Vitamins E,D3, and K1 in Plasma by Liquid Chromatography-Atmospheric Pressure Chemical Ionization-Mass Spectrometry Utilizing a Monolithic Column

This paper reports a rapid, simple, and sensitive method for determination of vitamin D3, vitamin E acetate, and vitamin K1 in plasma using atmospheric pressure chemical ionization –high performance liquid chromatography–mass spectrometry. Plasma samples were prepared using solid phase extraction. The separation of compounds was achieved using a C₁₈ monolithic column and a mobile phase composed of methanol and 0.1% formic acid in gradient elution mode at a flow rate of 1.0 mL min^?1. Analytes were ionized using atmospheric chemical ionization in positive mode. Mass spectra were recorded at m/z = 385.23, 473.47, and 451.41 for vitamin D3, vitamin E, and vitamin K1, respectively. Vitamin D2 was used as an internal standard and its mass spectra was recorded at 397.28 m/z. The method was validated using ICH guidelines. The system suitability responses were calculated for retention time, number of theoretical plates, capacity factor, resolution, and the selectivity factor. System validation was evaluated for precision, specificity, and linearity of all compounds. The limits of detection for vitamin D3, vitamin E, and vitamin K1 were determined to be 0.1, 1.36, and 0.052 ng mL^?1, respectively. The accuracy, evaluated as % of recovery, was in the range of 96.4 to 102.4% and precision determined as the coefficient of variation was between 1.24 and 3.6%. The validated method was applied to real plasma samples.     

镁离子、维生素E抗氧化作用的研究

为研究镁离子、维生素E体内外抗氧作用,探讨镁离子抗氧化作用的机制,将3月龄昆明种小鼠70只随机分7组,设正常对照组、氧化对照组、63、42、21mmol／L镁保护组,镁和维生素E保护组,维生素E保护组,饲养10d,腹腔注射0．15％CCl4致小鼠肝损伤,观察镁离子、维生素E对小鼠肝匀浆中MDA、SOD、GSH含量的影响;在肝匀浆中加入FeSO4和H2O2诱导自由基的生成,观察镁离子、维生素E的抗氧化作用。结果表明,镁离子、维生素E能显著降低肝匀浆中脂质过氧化物MDA的含量,对SOD、GSH无明显影响。提示镁离子、维生素E能抑制自由基的生成,促进自由基清除作用。     

Design,synthesis and cytotoxic activity of vitamin E bearing selenium compounds against human breast cancer cell line (MCF-7)

A new series of vitamin E/selenated pyridine, vitamin E/selenated pyridazine, vitamin E/selenated coumarine and vitamin E/selenated nicotine moieties were synthesized and their cytotoxic activity is investigated using the human breast cancer cell line. The newly synthesized compounds were characterized using spectroscopic tools (IR, ¹H NMR, ¹³C NMR, and mass spectroscopy) as well as microanalysis. Our study reveals that compound vitamin E/selenated nicotine moiety has the highest cytotoxic effect than the other synthesized compounds.