黄体素和β-胡萝卜素清除超氧阴离子和羟自由基能力的比较

利用抑制邻苯三酚自氧化法和番红花红漂白法分别检测离体条件下黄体素和β-胡萝卜素（从紫苜蓿叶片中提取的）对超氧阴离子（O2^-·）、羟自由基（·OH）清除作用的结果表明：黄体素清除O2^-·能力为β-胡萝卜素的2．78倍,清除·OH的能力是β-胡萝卜素的3.46倍。     

白细胞介素6和病毒感染与免疫

白细胞介素6(Interleukin 6,IL-6)是一种多效性细胞因子，对机体免疫系统和非免疫系统的细胞均有较大影响，可发挥促炎或抗炎作用，影响机体生理平衡。病毒感染致病往往包括直接损伤和免疫病理机制，免疫调节是影响疾病进程和临床结果的重要干预靶点。IL-6拮抗剂的临床应用经验提示，靶向该细胞因子可改善疾病结局，但如何以及何时阻断是仍需进一步研究的重要领域。为增加对IL-6在疾病进程中的作用机制的理解，我们对IL-6主要功能、信号转导途径以及在病毒感染与免疫中的作用进行了初步的综述分析。     

北京鸭血清HDL主要载脂蛋白的高效液相层析分离及其理化性质

用高效液相层析(HPLC)对北京鸭血清高密度脂蛋白(HDL)的所有载脂蛋白(apo)分离纯化,得五个主要apo峰,经SDS-PAGE鉴定,均为单一带;并做了IEF、糖基含量分析;对其中含量高的四个apo峰样进行了氨基酸组成测定和N-端部分氨基酸序列分析;从所做理化性质的研究,发现北京鸭血清HDL中的主要apo为:A-Ⅰ、C-Ⅲ_o、apoC-Ⅲ_s(s=1,2)、apoC's及可能的A-Ⅲ,几乎不含E和A-Ⅱ_o北京鸭HDL中apo的上述组成特点明显不同于易患动脉粥样硬化(As)的人及兔等动物,在一定程度上决定了北京鸭HDL的形成与代谢具有其特点,该特点与北京鸭不易形成As密切相关。     

RNA激活效应研究

RNAa(RNA activation)即RNA激活效应,是指某些小分子非编码RNA(non-coding RNA,ncRNA)在转录水平上激活基因表达的现象,这种发挥激活作用的小RNA分子又叫激活小RNA(small activating RNA,saRNA)。saRNA与干扰小RNA(small interfer-ing RNA,siRNA)同属小分子双链非编码RNA家族,既有相似的分子特征,在靶序列、作用动力学和调控方式等方面又有显著差别。虽然RNAa的作用机制尚未完全明了,但其在肿瘤治疗中的应用前景吸引了人们的关注。本文就RNAa近年的研究进展进行了简要综述。     

筼筜湖浮游植物细胞裂解率的时空变化

酶测定法作为现场测定浮游植物裂解速率的方法已被广泛应用于各种水体环境中。本论文对厦门市筼筜湖的浮游植物裂解速率的时空变化展开调查,探讨了浮游植物裂解速率的时空变化及其影响因素。调查期间,测定了内湖与外湖的溶解性酯酶活性,颗粒态酯酶活性及浮游植物裂解速率,同时测定了水体的叶绿素浓度及其他环境参数。综合分析各种指标,结果显示:浮游植物细胞裂解速率在空间上变化不大,时间上变化较大。在七月份由于水体中的病毒含量较高,浮游植物裂解速率较高。裂解速率在八月份与九月份降低,并且其数值变化不大。     

一氧化氮对豆科植物结瘤及固氮的影响机制

豆科植物-根瘤菌共生过程受双方基因复杂且精细的调控, 能够产生特异的根瘤结构并可将大气中的惰性氮气(N₂)转化为可被植物直接利用的氨态氮。结瘤与固氮受多种因素影响, 其中, 一氧化氮(NO)作为一种自由基反应性气体信号分子, 可参与调节植物的许多生长发育过程, 如植物的呼吸、光形态建成、种子萌发、组织和器官发育、衰老以及响应各种生物及非生物胁迫。在豆科植物中, NO不仅影响寄主与菌共生关系的建立, 还参与调控根瘤菌对氮气的固定并提高植株氮素营养利用效率。该文主要从豆科植物及共生菌内NO的产生、降解及其对结瘤、共生固氮的影响和对环境胁迫的响应, 阐述了NO调控豆科植物共生体系中根瘤形成和共生固氮过程的作用机制, 展望了NO信号分子在豆科植物共生固氮体系中的研究前景。     

SPINDLY 与赤霉素的信号转导

SPINDLY(SPY)作为一负调节子参与GA的信号转导,34肽重复结构(TPR)与C-端区域对其正常功能都十分重要。SPY基因在植物中呈组成型表达,其蛋白主要出现在细胞核部位。SPY蛋白与动物中的氧连N-乙酰葡萄糖胺转移酶(OGT)具有广泛的同源性,两者可能有着类似的作用机制。本文主要介绍GA突变体、SPY基因、SPY蛋白及其在大麦中的同源物HvSPY的结构与功能相关方面的一些研究进展。     

盐胁迫下三色苋甜菜碱及有关酶含量的变化

三色苋(Amaranthus tricolor)不同器官中的甜菜碱(GB)含量显著不同.除子叶外,根、茎和叶的GB含量和茎、叶中的胆碱单加氧酶(CMO)含量都因300 mmol/L的NaCl处理而增加.甜菜碱醛脱氢酶(BADH)的表达无论盐处理与否在所有器官中都能检测到,其含量变化不大.当种子发芽时,具备合成GB的能力,CMO含量增加;在此之前未能检测到CMO,也不能合成GB.研究结果表明三色苋响应盐胁迫而合成GB的关键酶是CMO.     

Visfatin在非酒精性脂肪性肝病发展过程中的表达及意义

观察血清及肝脏组织中内脂素(Visfatin)的表达情况,探讨其在非酒精性脂肪性肝病(nonalcoholic fattyliver disease,NAFLD)发生、发展过程中的作用.以高脂饮食构建NAFLD大鼠模型,应用酶联免疫吸附法、RT-PCR及免疫组织化学等方法,动态检测大鼠NAFLD发展过程中血清Visfatin的含量及其在肝组织中的表达.结果显示:在模型组大鼠由单纯性脂肪肝(SS)发展为非酒精性脂肪性肝炎(NASH)的过程中,Visfatin在大鼠血清和肝组织中的表达均呈现由高到低的变化趋势,SS组大鼠Visfatin的表达显著高于正常对照组和NASH组(P<0.01),而正常对照组和NASH组之间无明显差异;SS组大鼠Visfatin主要表达于小叶中央静脉周围脂肪变性相对较轻的肝细胞内.由此认为,Visfatin在血清和肝组织中的高表达作为早期事件,可能在NAFLD发展过程中起重要作用.     

核仁小RNA源性小RNA

最新研究结果表明,一些与RNA介导基因沉默相关的小RNA由核仁小RNA(small nucleolar RNA,snoRNA)加工产生,这种小RNA被称为核仁小RNA源性小RNA(snoRNA derived small RNA,sdRNA)。sdRNA现象分布物种广;涉及的snoRNA种类全,数量多;产生的小RNA分子大小不一、数量、种类多。表明这种小RNA在生物中存在着广泛的普遍性。sdRNA的发现拓展了snoRNA的功能,揭示了snoRNA与RNA介导的基因沉默之间的紧密关系,增强了snoRNA在RNA调控网络中的重要性,并为进一步研究RNA调控网络开启了一扇门。     

叶黄素酯的皂化工艺研究

本文研究了以金盏菊提取物为原料,通过皂化反应将其中叶黄素酯类衍生物转化为游离态叶黄素的皂化工艺。考察了溶剂类型、KOH浓度、反应时间、反应温度和KOH溶液加入量对衍生效果的影响。     

Changes in Macular Pigment Optical Density and Serum Lutein Concentration in Japanese Subjects Taking Two Different Lutein Supplements

Purpose

To investigate macular pigment optical density (MPOD) and serum concentration changes of lutein in Japanese subjects participating in a clinical trial in which two formulations of lutein and zeaxanthin supplements with different physiochemical properties are used.

Methods

Thirty-six healthy volunteers were recruited into this prospective, randomized, parallel-group, double-masked comparative study at a single institute. Two products were used, FloraGLO® (Kemin Japan) and XanMax® (Katra Phytochem). The lutein particle size and zeaxanthin concentrations differed between the formulations. The subjects consumed one of the two supplements for a duration of up to 6 months. MPOD levels were measured by resonance Raman spectrometry at baseline and once a month until the end of the study. Serum lutein concentration was measured at baseline, month 3, and month 6. The subjects were also tested for contrast sensitivity, glare sensitivity, visual acuity, and in addition had a focal electroretinogram measured.

Results

The mean serum lutein concentrations increased significantly after the first three months, but the mean MPOD levels in either supplement group did not show any statistically significant increase. A detailed analysis, however, revealed three response patterns in both groups for the increase of MPOD levels and serum lutein concentration, i.e. “retinal responders”, who had an increase of both MPOD levels and serum lutein concentrations (n = 13), “retinal non-responders”, who had only increased serum concentrations and no change in MPOD levels (n = 20), and “retinal and serum non-responders”, who had neither MPOD level nor plasma concentration increases (n = 3). The subjects with low MPOD levels at baseline appeared to show increased MPOD levels at the 6 month time point upon lutein supplementation (r = -0.4090, p = 0.0133). Glare sensitivity improved in retinal responders in both supplement groups, while there were no remarkable changes in contrast sensitivity.

Conclusions

No statistically significant differences could be detected for MPOD levels and serum lutein concentrations between the two investigated lutein supplement formulations. Responses to lutein supplementation regarding MPOD levels and serum lutein concentrations varied between subjects. Subjects with lower MPOD levels at baseline responded well to lutein supplementation. However, since the number of subjects was low, a further study with more subjects is needed to prove that subjects with low MPOD levels will benefit from lutein supplementation.

Trial Registration

UMIN-CTR UMIN000004593     

Lutein and cataract: from bench to bedside

Cataract is one of the most important leading causes of blindness in the world. Extensive research showed that oxidative stress may play an important role in the initiation and progression of a cataract and other age-related eye diseases. Extra-generation of reactive oxygen and nitrogen species in the eye tissue has been shown as one of the most important risk factors for cataracts and other age-related eye diseases. With respect to this, it can be hypothesized that dietary antioxidants may be useful in the prevention and/or mitigation of cataract. Lutein is an important xanthophyll which is widely found in different vegetables such as spinach, kale and carrots as well as some other foods such as eggs. Lutein is concentrated in the macula and suppresses the oxidative stress in the eye tissues. A plethora of literature has shown that increased lutein consumption has a close correlation with reduction in the incidence of cataract. Despite this general information, there is a negligible number of review articles considering the beneficial effects of lutein on cataracts and age-related eye diseases. The present review is aimed at discussing the role of oxidative stress in the initiation and progression of a cataract and the possible beneficial effects of lutein in maintaining retinal health and fighting cataract. We also provide a perspective on the chemistry, sources, bioavailability and safety of lutein.     

Lutein, zeaxanthin, and the macular pigment

The predominant carotenoids of the macular pigment are lutein, zeaxanthin, and meso-zeaxanthin. The regular distribution pattern of these carotenoids within the human macula indicates that their deposition is actively controlled in this tissue. The chemical, structural, and optical characteristics of these carotenoids are described. Evidence for the presence of minor carotenoids in the retina is cited. Studies of the dietary intake and serum levels of the xanthophylls are discussed. Increased macular carotenoid levels result from supplementation of humans with lutein and zeaxanthin. A functional role for the macular pigment in protection against light-induced retinal damage and age-related macular degeneration is discussed. Prospects for future research in the study of macular pigment require new initiatives that will probe more accurately into the localization of these carotenoids in the retina, identify possible transport proteins and mechanisms, and prove the veracity of the photoprotection hypothesis for the macular pigments.     

叶黄素的抗癌作用及其研究现状

叶黄素是自然界广泛存在的类胡萝卜素,可以提高人体的免疫能力,也是一种抗氧化剂,对老年视黄斑退行性变化有很好的预防作用,但更重要的是研究表明,叶黄素对一些类型的癌症具有预防效果。本综述了近年来有关叶黄素预防癌症作用的流行病学调查、分析,以及与癌症关系的实验研究及作用机制等方面的研究进展。     

OVARIAN STEROID CELLS : II. The Lutein Cell

The lutein cells of the rabbit exhibit fine structural variations during their life-span of 28 to 30 days. A systematic examination of the corpus luteum reveals that cellular distinctions may be recognized during the first, second, and third stages of pregnancy. The agranular endoplasmic reticulum reveals vesicular, tubular, and cisternal profiles after fixation with each of the following fixatives: glutaraldehyde, osmium tetroxide, and permanganate. The osmolality of the fixing solutions was varied with sucrose and recorded with an osmometer in order to determine the effect of osmotic concentration on the intracellular membranous profiles. It was determined that vesicles and short, branched tubules of similar structure are present in the agranular reticulum when the osmolalities are 300 to 800 milliosmols (iso-osmotic considered 300 milliosmols). At 900 milliosmols, the vesicular or tubular lumen is obliterated. Intracellular membrane profiles do not exhibit interconversions due to hyperosmotic fixative solutions. The agranular endoplasmic reticulum is randomly distributed as short tubular profiles during the first third of pregnancy. A continuity between these membranes and irregular, electron-opaque lipid masses is evident. When physiological and histochemical data indicate that the lutein cell may be storing sterol precursors, cytological observations show that the agranular endoplasmic reticulum exists in a more organized pattern within the cytoplasmic matrix. Vesicular and short tubular, circular aggregations as well as whorled cisternal patterns surround the larger, less electron-opaque lipid droplets. Surface views of cisternal agranular endoplasmic reticulum exhibit tubular extensions, accentuating the continuity between these two profiles. During the progress of pregnancy, the lutein cell increases in diameter, and accumulates both lipid inclusions and aggregations of intracellular membranes. The agranular endoplasmic reticulum may be peripherally packed and arranged parallel to the cell surface during later stages. In the postpartum, degenerating lutein cell, large myelin figures are present which form from the agranular endoplasmic reticulum. These cellular events are discussed in relation to lutein cell activity, including both secretion of product and storage of precursors.     

Lutein effect on retina and hippocampus of diabetic mice

Oxidative stress markers and functional tests were studied to confirm early biochemical and functional changes in retina and hippocampus of diabetic mice. The effects of lutein treatment were also tested. Mice were induced diabetic by alloxan injection and divided into subgroups: control, control+lutein, diabetic, diabetic+lutein, diabetic+insulin, and diabetic+insulin+lutein. Treatments started on Day 4 after alloxan injection and animals were sacrificed on Day 14. Malondialdehyde and glutathione concentrations and glutathione peroxidase activity were measured as oxidative stress markers. The following functional tests for retina and hippocampus were performed: electroretinogram and Morris water maze test. NFkappaB activity was also measured. Oxidative stress and NFkappaB activity increase in the retina and hippocampus after 15 days of diabetes. Impairment of the electroretinogram and a correlation between latencies of the water maze test and glycated hemoglobin (HbA1c) levels were observed. Lutein prevented all these changes even under hyperglycemic conditions. Retina appears to be affected earlier than hippocampus by diabetes-induced oxidative stress. Although a proper glycemic control is desirable in preventing the development of diabetic complications, it is not sufficient to prevent them completely. Lutein could be an appropriate coadjuvant treatment for the changes observed in this study.     

由天然叶黄素转化为玉米黄素的工艺参数的研究

本文通过碱催化反应使叶黄素异构化为玉米黄素,并对实验中的主要影响因素进行了优化.实验结果表明,以1,2-丙二醇为溶剂,氢氧化钾为催化剂,1,2-丙二醇/叶黄素(v/m)为20,氢氧化钾/叶黄素为6,反应温度为110℃,反应时间为168 h时,叶黄素转化为玉米黄素的转化率最高,达93％.     

Absorption and Ocular Deposition of Dietary Lutein in Marine Mammals

Cataracts and ocular disease are common lesions of marine mammals in zoological collections. Lutein, an oxygenated carotenoid, may have therapeutic or prophylactic effects on ocular disorder. Therefore, this study examined the ability of marine mammals to absorb dietary lutein. Two preliminary trials examined lutein in two forms (beadlet or ester) in a small sample size of marine mammals representing pinnipeds and cetaceans. Lutein was fed daily in tablets providing 0.89–3.6 mg lutein/kg body weight^0.75 per day for 15 days to 2 years. A third study was conducted using lutein beadlet fed at 3.6 mg lutein/kg body weight^0.75 per day for 15–21 days. Blood was analyzed for lutein pre‐ and postsupplementation. In the preliminary trials, lutein beadlet was observed to result in greater blood lutein levels than lutein esters, and cetaceans had more noticeable responses than pinnipeds. In Study 3, serum lutein and zeaxanthin increased postsupplementation in beluga whales (P < 0.05), and serum lutein tended to increase postsupplementation in dolphins (P < 0.10), but little change was seen in serum lutein in pinnipeds or manatee. Opportunistic retinal samples demonstrated some detectable lutein in the retina of a dolphin and several harp seals. The lutein levels in dolphins after supplementation are similar to those reported in free‐ranging animals. Ocular lutein in harp seals demonstrates that ocular deposition occurs despite low circulating lutein levels. Zoo Biol. 32:316–323, 2013. © 2012 Wiley Periodicals, Inc.     

微胶囊叶黄素理化性质及其稳定性研究

本文研究了微胶囊叶黄素产品的理化性质及其在光、热、pH值及氧气条件下的稳定性。结果表明,微胶囊叶黄素含水率为3．0％、密度0．39g／cm^3、粒径8—10μm、溶解度90s;叶黄素经微胶囊化后可明显提高叶黄素的光稳定性和热稳定性,减弱了pH值的影响和氧气对叶黄素的氧化降解。