Alpha-tocopherol supplementation on chromium toxicity: a study on rat liver and kidney cell membrane

Membrane damage is one of the important consequence of chromium, an environmental toxicant, to produce cytotoxicity. α-tocopherol, a membrane protectant can be used to reduce the chromium-induced membrane damage. In the present study, the impact of chromium in presence and absence of α-tocopherol was studied on plasma membrane of liver and kidney in male Wistar rats (80—100 g body weight). Significant increase in membrane cholesterol level as well as significant decrease in membrane phospholipid level in chromium exposed ( 0.8 mg /100 g body weight/d, i.p., for 4 weeks) animals suggest structural alteration of both liver and kidney plasma memebrane. The alkaline phosphatase, total ATPase and Na +-K +-ATPase activities of plasma membrane were significantly decreased in both liver and kidney after chromium treatment. However, α-tocopherol (30 mg/100 g diet) supplementation can restrict the changes in these membrane-bound enzyme activities. Thus, the usefulness of dietary supplementation of α-tocopherol to restrain the chromium-induced membrane damage is suggested.

Synthesis of d,l-α-Tocopherol Catalyzed by Heteropoly Acids

,d,l-a-Tocopherol (vitamin E) isfound to be synthesized by condensingtrimethylhydroquinone with isophytol catalyzed by heteropoly acids (HPA) H3:PW12O40 andH3PMo12O40 at room temperature. These HPA are efficient catalysts for the synthesis of d l-a-Tocopherol and can easily be separated from the reaction mixture and roused,

Protective Effects of α-Tocopherol against Brain Tissue Damage Induced by Intracerebral Hemorrhage in SD Rats

Lipid peroxidation mediated by oxygen radical is one of the main mechanisms underlying secondary brain injury. Among all vitamin E compounds, α-tocopherol shows the most prominent antioxidative effects. It plays an important role in cell aging and injury. However, there has been no report regarding the effects of α-tocopherol on changes in brain tissue morphology after intracerebral hemorrhage (ICH), cerebral edema, or the expression of Bax and Bcl-2 proteins. We use SD rats to carry out the related studies;based on the atlas of SD rats, the caudate nucleus was positioned using a stereotaxic apparatus, and 50 μl autologous tail artery blood was injected to caudate nucleus in the ICH and α-tocopherol groups to establish ICH model. Rats in the sham surgery group received the same volume of saline in the caudate nucleus. Rats in the α-tocopherol group received intraperitoneal injections of α-tocopherol at 600 mg/kg every day. Rats in the ICH group and sham surgery group received the same amount of saline at the same times as those in the α-tocopherol group. We observed some interesting results: comparisons of brain tissue sections of rats from different groups showed that brain tissue damage and functional neurological deficits among rats from the α-tocopherol group were less pronounced than in the ICH group. Wet weight/ dry weight measurement showed that rats from the α-tocopherol group exhibited less cerebral edema than those in the ICH group. Rats from the α-tocopherol group showed less Bax expression and more Bcl-2 expression than those in the ICH group.

Influence of a-tocopherol on nickel induced alteration of serum lipid profile in male albino rats

We studied the effect of the simultaneous treatment withα-tocopherol(100 mg / kg;im) and nickel sulfate (20 mg/kg,ip) on nickel-induced changes in serum lipid profiles.Nickel-treated rats showed a significant increase in serum LDL cholesterol,total cholesterol,triglycerides,and a significant decrease in serum HDL cholesterol. Simultaneous administration ofα-tocopherol with nickel sulfate improved LDL-cholesterol and HDLcholesterol level when compared with rats receiving nickel sulfate alone.The results indicate thatα-tocopherol is beneficial in preventing nickel-induced lipid profile alterations.

Reduced expression of α-tocopherol-associated protein is associated with tumor cell proliferation and the-increased risk of prostate cancer recurrence

Aim： To examine the impact and prognostic significance of α-tocopherol associated protein （TAP） expression in a series of prostate cancer patients. Methods： Tissues from 87 patients underwent radical prostatectomy were examined for TAP expression by immunohistochemistry. The relationships of the staining results, the clinic pathological characteristics and the recurrence times were analyzed. Results： Compared with the adjacent areas of normal and benign glands, immunoreactivity of TAP was reduced in areas of prostate cancer. A lower TAP-positive cell number per mm^2 of the largest cancer area （defined as TAP-PN） was associated with higher clinical stage （r = -0.248, P = 0.0322）. Inverse associations were found among the TAP-PN and positive lymph nodes （r = -0.231, P = 0.0325）, preoperative prostatespecific antigen （PSA） levels （r = -0.423, P = 0.0043）, tumor size （r = -0.315, P = 0.0210） and elevated tumor cell proliferation, which was indicated by the staining of Ki-67 （r = -0.308, P = 0.0026）. TAP-PN was a significant predictor of recurrence univariately （P = 0.0006）, as well as multivariately, adjusted for known markers including preoperative PSA, clinical stage, Gleason score, surgical margin, extra-prostatic extension, seminal vesicle invasion and lymph node metastasis （P = 0.0012）. Conclusion： Reduced expression of TAP was associated with the cell proliferation status of prostate cancer, adverse pathological parameters and the increased risk of recurrence.

Maternal reproductive health: Expression patterns of antioxidant enzyme selenoproteins of post-implantation embryos conceived by ethanol-treated murine mothers supplemented with α-tocopherol

Objective:To investigate if the protective effect ofα-tocopherol against the impact of ethanol on brain morphogenesis involved the activity of the selenoproteins phospholipid hydroperoxide glutathione peroxidase (PHGPx;GPx4) and selenoprotein P (SelPP) that have roles against oxidative stress.Methods:Forty female mice were randomly assigned into natural control (CON), positive control (ETOH), low-, medium-, and high-α-tocopherol-supplemented-ethanol groups (LTOC, MTOC, HTOC, respectively). CON received drinking water without ethanol while ETOH, LTOC, MTOC and HTOC groups received 20% ethanol in drinking water. The supplemented groups were given respective dosages ofα-tocopherol, 0.410, 0.819, and 1.640 mg/g body weight, at day 14 before mating onwards to the day 9 of gestation. At 10.5 ED of gestation (1100 h), the pregnant females were sacrificed by cervical dislocation and the embryos were harvested. Total RNA were extracted, cDNA synthesis and qRT- PCR analyses were carried out.Results: The level of expression of PHGPx in the positive control was significantly lower than that of the natural control. Among the threeα-tocopherol-supplemented groups, only the medium dose- group was significantly higher than the positive control. The level of expression of SelPP in the positive control was significantly lower than those of the natural control, the low- and medium- dose -tocopherol supplemented groups. In the high dose-α-tocopherol supplemented group, the level of expression was not significantly different from the positive control but significantly lower than the natural control.Conclusions: The activity of the selenoproteins PHGPx and SelPP are involved in the internetwork of antioxidative enzymes with vitamin E when given up to a medium dose only and is one of the possible pathways of shielding embryonic development against the impact of ethanol on brain morphogenesis. This study strengthens the impact of dietaryα-tocopherol and Selenium supplement during the critical period of pregnancy.

Neuroprotective effects of low-concentration alpha-tocopherol Confocal laser microscopy observations

BACKGROUND： Alpha-tocopherol （ α-tocopherol） can effectively relieve neuronal damage induced by oxygen-centered free radicals. However, the effective dose remains controversial. OBJECTIVE： To evaluate the protective effects of low-concentration α-tocopherol on neuronal membranes. DESIGN, TIME AND SETTING： Contrast observation and in vitro study, performed at Laboratory of Neurosurgery, Tianjin Huanhu Hospital between April and September 2006. MATERIALS： Fetal cortical neurons were derived from two 14-day pregnant SD rats, and α-tocopherol was provided by Sigma, USA. METHODS： The neurons were randomly assigned to six groups： （1） normal： neurons were cultured under normal conditions; （2） oxidative damage： oxidative free radicals was damaged using the Fenton reaction; （3） α-tocopherol： neurons were cultured in different concentrations of -tocopherol 10, 20, 40, and 80 mg/L for 2 hours, respectively. MAIN OUTCOME MEASURES： Neuronal membrane damage was observed using a confocal laser microscope, and malonaldehyde production was detected using the thiobarbituric acid method. RESULTS： At normal, biological concentrations （10 mg/L）, α-tocopherol induced no change in the damaged neurons （P 〉 0.05）. However, at a concentration of 80 mg/L, the number of damaged neurons was significantly reduced, compared with the damage group （P 〈 0.05）. Malonaldehyde levels following 80 mg/L α-tocopherol treatment were less than the oxygen free radical damage group （P 〈 0.05）, but greater than the control group （P 〈 0.01）. CONCLUSION： A concentration of 80 mg/L α-tocopherol can effectively protect the neuronal cell membrane from oxidative damage

A Methodological Approach to Study Almond Oil Stability in Relation to <i>α</i>-Tocopherol Supplementation

The objectives of the present study were to identify a suitable parameter to assess the oil oxidation and to study the possibilities of delaying the oxidation of moderately oxidized unrefined almond oil by adding supplementary amounts of α-tocopherol. Three oil samples, with initial peroxide values of 13.3, 19.5 (moderately oxidized oils), and 28.9 (oxidized oil), were supplemented with 100, 250 and 500 ppm of α-tocopherol and subjected to the oxidation at 50°C for 9 days. The level of oxidation was determined by measuring peroxide value (PV), conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS). Chemometric analysis indicated that, under the conditions of the present study, PV was the most suitable indicator of oil oxidation. The results have shown that the α-tocopherol could have an anti- oxidant or pro-oxidant effects, depending on its concentration and initial level of oil oxidation. Results also show that α-tocopherol addition at all the concentrations tested resulted in pro-oxidation of the moderately oxidized oils;hence additional supplementation with α-tocopherol could not be recommended to delay oxidation of unrefined almond oil.

Influence of Glutaraldehyde on the Properties and Release Kinetic of α-Tocopherol from Chitosan-based Film

A crosslinked chitosan film with α-tocopherol was produced by a solution casting method. The appearance, mechanical properties, morphology, barrier properties and release kinetics of the α-tocopherol were evaluated. The addition of glutaraldehyde and α-tocopherol decreased the lightness and greenness and increased the yellowness of the chitosan-based film. Moreover, it also affected the compatibility of the film due to a decrease in the opacity values. The elongation at break(EB) and tensile strength(TS) values of the film decreased when the glutaraldehyde and α-tocopherol were added. In contrast, the Young’s modulus(YM) values increased. SEM micrographs showed coarse spots and pores on the surface and cross-section of the film when compared with the chitosan film. Based on the results, it was indicated that the chitosan structure was disconnected by the α-tocopherol, and the glutaraldehyde as a crosslinking agent generated a link between the chitosan network, which could be the cause of the reduced flexibility and the increased surface roughness of the film. However, the glutaraldehyde and α-tocopherol did not result in a significant difference in water vapour permeability(WVP) values. The glutaraldehyde influenced the release kinetics of the α-tocopherol as seen by the decrease of the diffusion coefficient values that were calculated using the Fickian diffusion model.

Photooxidation of α-Tocopherol in Micelles. A New Singlet Oxygen Oxidation Product

Methylene blue sensitized singlet oxygen oxidation of dl-α-tocopherol in dodecylsulfate (SDS) or cetyl trimethyl ammonium brondde (CTAB) ndcelles led to the formation, besidesα-tocopherol quinone and its epoxide, of a hitherto unknown spiro compound 6-hydroxy-2,6,8,9-tetramethyl-2-phytyl- 1-oxaspiro [4, 5] dec -8 - en - 7, 10-dione.

Effect of Polysaccharide Species on Storage Stability of Alginate Capsules Containing <i>α</i>-Tocopherol

Alginate capsules containing α-tocopherol were prepared adding polysaccharide species such as κ-carrageenan, gellan gum, pectin, curdlan and ghatti gum. The effects of polysaccharide species and the diameters of α-tocopherol on storage stability of the capsules were investigated and characterized in detail. As the contact angle of α-tocopherol to the capsule shell strongly affected storage stability, the contact angle was measured on the model sheet made of calcium alginate with polysaccharide species. The leakage ratio decreased with the contact angle and increased with the diameter of α-tocopherol. The capsules made of calcium alginate with gellan gum showed the largest contact angle and the highest storage stability. The capsules made of calcium alginate with curdlan, ghatti gum and pectin were harder than other capsules and showed higher storage stability. All the capsules showed the almost similar swelling ratio in the acidic solution with pH 4, but showed the different swelling ratios according to the polysaccharide species in the alkali solution with pH 9. The tablets were prepared with the wet and the dried capsules. The tablets prepared with the dried capsules showed higher storage stability.

添加剂对多花黑麦草青贮发酵品质、α-生育酚和β-胡萝卜素含量的影响

为提高多花黑麦草青贮发酵品质,减少α-生育酚、β-胡萝卜素含量损失,以无添加为对照,研究了添加剂:0.4%丙酸(PA)、植物乳杆菌(LP)、环状芽孢杆菌(BC)、植物乳杆菌和环状芽孢杆菌菌株混合添加(LP+BC)对青贮发酵品质、α-生育酚和β-胡萝卜素的影响,在青贮3、7、35和70 d后开窖取样,检测发酵品质、营养成分、α-生育酚和β-胡萝卜素含量。结果表明:添加剂对多花黑麦草发酵品质有显著影响(P<0.05),LP+BC组提高青贮发酵品质的效果最好,其次为LP组。青贮70 d后,与对照组相比,添加剂组均降低了饲料的pH,且pH都在4.0以下。LP、BC和LP+BC组提高了乳酸含量和乳酸乙酸比(P<0.05);PA组在青贮初期抑制了乳酸发酵,后期提高了青贮发酵品质,但提高效果不如其余3种添加剂。在各个青贮时期,PA组的α-生育酚含量均显著高于其余4组(P<0.05);在青贮35和70 d时,除PA组外,LP组α-生育酚含量最高(P<0.05)。青贮7 d后,各添加剂组β-胡萝卜素含量均显著高于对照组(P<0.05),LP组在青贮7和35 d时β-胡萝卜素含量最高(P<0.05)。综上所述,LP组处理下多花黑麦草青贮发酵品质良好且减少了α-生育酚含量损失,增加了β-胡萝卜素含量。

温度和添加剂对象草青贮发酵品质、α-生育酚和β-胡萝卜素的影响

为提高青贮饲料的发酵品质,降低α-生育酚和β-胡萝卜素的损失,研究了温度(45,30和15℃)和添加剂(无添加:CK;纤维素酶:E;植物乳杆菌:LP)对象草青贮饲料的影响。试验结果表明,在所有温度水平,象草青贮饲料的发酵品质良好,但30℃时产生了少量丁酸,发酵品质略有下降;添加LP和E降低了pH(P<0.05),增加了乳酸含量和乳酸乙酸比(P<0.05),提高了发酵品质。象草青贮饲料贮藏在45和15℃时的α-生育酚含量显著高于30℃(P<0.05),β-胡萝卜素含量显著低于30℃(P<0.05)。LP和E添加组在所有温度水平的α-生育酚和β-胡萝卜素含量均较低(P<0.05)。E组在45℃的α-生育酚含量显著高于LP组,E组在30和15℃的β-胡萝卜素含量显著高于LP组。

添加剂对象草青贮发酵品质、α-生育酚和β-胡萝卜素的影响

为提高青贮饲料的发酵品质,降低α-生育酚和β-胡萝卜素的损失,研究了添加剂(无添加,CK;邻叔丁基对苯二酚,T;植物乳杆菌,L;植物乳杆菌和邻叔丁基对苯二酚组合添加,TL)和贮藏时间(35d和70d)对象草(Pennisetum purpureum Schumach.)青贮品质的影响。结果表明:在两个贮藏时间,象草青贮饲料发酵品质都良好;L和TL组降低了饲料pH(P<0.05),增加了乳酸含量和乳酸乙酸比(P<0.05);T组在两个贮藏时间的所有发酵品质参数与CK组无显著差异。L和TL组在两个贮藏时间的α-生育酚显著低于CK组和T组(P<0.05),T和TL组在贮藏70天的β-胡萝卜素含量显著低于CK组(P<0.05)。综上所述,无添加剂的象草低温15℃贮藏70d后的青贮发酵品质良好,α-生育酚和β-胡萝卜素的损失较小。

β-胡萝卜素和α-生育酚协同抗氧化作用的微环境效应

分别用水溶性和脂溶性的偶氮引发剂2，2＇－偶氮二（2－眯基丙烷）二盐酸盐（AAPH）和连二次硝酸二叔丁酯（DBHN）引发亚油酸的过氧化，用氧气吸收法研究了β-胡萝卜素（β－C）和α-生育酚（VE）在负离子胶束十二烷基硫酸钠（SDS）、非离子胶束辛基苯基聚氧乙烯醚（TritonX－100）和正离子胶束十六烷基三甲基溴化铵（CTAB）中对亚油酸自动氧化的抗氧化和协同抗氧化作用．发现它们的抗氧化活性强烈地依赖于介质的微观环境及引发剂的亲脂性．β-C仅在SDS胶束中对DBHN引发的亚油酸过氧化有明显的抗氧化作用，但在SDS和TritonX－100中β-C可以和VE协同作用，显著加强VE对AAPH和DBHN引发的亚油酸过氧化的抑制作用．讨论了抗氧化活性与介质微环境的关系．

超声波辅助提取植物油中甾醇和生育酚

为优化食用植物油中主要营养物质的定量分析方法,建立了超声波辅助萃取LC-MS/MS测定食用油中植物甾醇和生育酚分析方法。在单因素实验的基础上,采取中心组合设计优化实验中超声时间和超声温度。通过优化分析得到食用油皂化提取豆甾醇、β-谷甾醇和δ-生育酚最优实验条件为：超声反应温度75℃,超声反应时间40min,功率100%。本方法中豆甾醇、β-谷甾醇、δ-生育酚的定量限分别为10.0ng/m L、10.0ng/m L和8.1ng/m L,相关系数均≥0.990 4,加标回收率在87.2%～97.8%之间,相对标准偏差为2.3%～8.6%。将建立的方法应用于茶籽油、紫苏子油、橄榄油、大豆油样品分析,结果表明本方法前处理操作简单且用时短、结果准确可靠,适用于食用植物油中主要甾醇和生育酚定量分析。

β-胡萝卜素、甾醇、磷脂、生育酚对油脂回色的影响

以中链脂肪酸甘油酯(MCT)为研究体系,采用105℃烘箱加热、30 d见光储存、30 d避光储存回色实验方法,系统研究了β-胡萝卜素、甾醇、磷脂和生育酚对油脂回色的影响。结果表明:β-胡萝卜素和甾醇不会对油脂回色造成影响;磷脂虽能加深油脂颜色,但不能造成油脂颜色可逆变化,因此也不是油脂回色的主要原因;生育酚是油脂回色的主要因素,微量的生育酚损失即可引起油脂颜色显著变化。

反相高效液相色谱法同时测定中成药保健食品中4种生育酚含量

目的建立同时测定中成药保健品中4种生育酚含量的反相高效液相色谱法。方法色谱柱为YMCCarotenoid-C30柱(250mm×4.6mm,5μm),流动相为甲醇-水(梯度洗脱),流速为0.8mL/min,检测波长为294nm,柱温为20℃,进样量为10μL。结果α,β,γ,δ-生育酚质量浓度线性范围分别为5.28~63.36,5.42~65.09,5.23~62.77,5.10~61.15μg/mL(r>0.999),精密度、稳定性、重复性试验的RSD均小于2%;平均加样回收率分别为95.77%,95.23%,97.43%,94.83%,RSD值分别为1.13%,1.86%,1.34%,1.73%(n=6)。结论该方法操作简便,准确,精密度、稳定性、重复性、耐用性均较好,可用于同时测定中成药保健品中4种生育酚含量。

3种天然抗氧化剂对菜籽油储藏稳定性影响的研究

采用Schaal烘箱法结合油脂氧化稳定性测定仪研究在不同添加量(50、100、150 mg/kg)下,3种天然抗氧化剂α-生育酚、番茄红素和β-胡萝卜素对菜籽油储藏过程中氧化稳定性的影响。结果表明:在国家允许添加量范围内,添加150 mg/kgα-生育酚的菜籽油货架期最长,储藏稳定性最好,色泽最为接近空白油样;α-生育酚在菜籽油中比较稳定,能更有效地延缓菜籽油氧化酸败,其效果优于番茄红素和β-胡萝卜素。

HPLC同时测定保健食品中维生素A、D_3、E和β-胡萝卜素

建立了一种同时测定保健食品中维生素A、D3、E、β-胡萝卜素的高效液相色谱法。样品皂化后乙醚提取，旋转蒸干，流动相溶解，HPLC紫外检测。实验结果显示，VA、VD3、VE和β-胡萝卜素的线性范围分别为0．012～500、0．030～500、0．12～500和0．015～500μg／mL，且浓度范围内线性良好；检出限分别为0．24、0．60、2．40和0．30μg/g；相对标准偏差分别为1．9％、3．4％、4．6％和2．9％；VA、VD、VE和β-胡萝卜素的加标回收率为84．8％-119．0％。分析周期在20min以内，方法适合保健食品样品的分析。