Lipofuscins prepared by modification of photoreceptor cells via glycation or lipid peroxidation show the similar phototoxicity

AIM To investigate the effect of two ways of lipofuscin production(lipid peroxidation and glycation) on lipofuscin fluorescence characteristics and phototoxicity and to compare them with the properties of natural lipofuscin.METHODS Model lipofuscins were prepared on the basis of bovine photoreceptor outer segments(POS) with bisretinoid A2 E addition. One set of samples was prepared from POS modified by lipid peroxidation,while another set from POS modified by glycation with fructose. Fluorescent properties and kinetics of photoinduced superoxide generation of model lipofuscins and human retinal pigment epithelium(RPE) lipofuscin were compared. The fluorescence spectra of samples were measured at 365 nm excitation wavelength and 380-650 emission wavelength. RESULTS The fluorescence spectra of model lipofuscins are almost the same as the spectrum of natural lipofuscin. Visible light irradiation of both model lipofuscins and natural lipofuscin isolated from RPE cells leads to decrease of a fluorescence maximum at 550 nm and to appearance of a distinct,new maximum at 445-460 nm. The rate of photogeneration of reactive oxygen forms by both model lipofuscins was almost the same and approximately two times less than that of RPE lipofuscin granules.CONCLUSION These data suggest that fluorescent characteristics and phototoxicity of lipofuscin granules depend only to an insignificant degree on the oxidative modification of POS proteins and lipids,and generally are defined by the bisretinoid fluorophores contained in them.

Ameliorative Action of Mn-Salen Derivatives on CCl₄-Induced Destructive Effects and Lipofuscin-Like Pigment Formation in Rats’ Liver and Brain: Post-Treatment of Young Rats with EUKs

Lipofuscin-like pigments (LFPs) are highly oxidized cross-linked aggregates of oxidized protein and lipids which are formed under oxidative state conditions by free radicals produced. The present study aimed to evaluate the probable ameliorative effects of some of the Mn-salens namely EUKs 8, 134, 15, 115, 122 and 132 (compounds 1-6) and vitamin C against carbon tetrachloride (CCl4)-induced acute damage on rats’ livers and brains. Exposure to CCl4 is believed to induce oxidative stress and cause tissue damage due to the formation of trichloromethyl (·CCl3) and peroxy trichloromethyl (·OOCCl3) radicals. In this study, 54 rats were randomly divided into 9 groups of six each: normal group received only vehicle (olive oil;2 ml/kg b.w.) for 6 consecutive days;CCl4- intoxicated group received the vehicle and CCl4 (50% solution of CCl4 in olive oil, 2 ml/kg b.w.) on the first and second days and the vehicle on the third to sixth days;test rats received Mn-salens or vitamin C (20 mg/kg b.w.) and CCl4 (2 ml/kg b.w.) on the first and second days and Mn-salens or vitamin C (20 mg/kg b.w.) on the third to sixth days. Mn-salens administration ameliorated the effects of CCl4 by decreasing the levels of ROS, lipid and protein oxidations and LFPs formation on liver and brain as well as cholesterol and triglycerides, aminotransferases and alkaline phosphatase contents in sera of rats whereas increased the activities of catalase, superoxide dismutase,glutathione reductase, glutathione peroxidase and reduced glutathione in liver and brain tissues. Histopathological studies confirmed the toxic effects of CCl4 and ameliorative action of Mn-salens on tissues. These results suggest that the evaluated EUKs were able to attenuate LFPs accumulation and morphological changes caused by CCl4 in rats and thus, confirming the ameliorative role of Mn-salens against CCl4-induced oxidative damage and age-related diseases.

Lipofuscin-and Melanin-related Fundus Autofluorescence in Patients with Submacular Idiopathic Choroidal Neovascularization

Purpose:.To compare melanin-related near-infrared fundus autofluorescence (NIA; excitation 787 nm, emission> 800 nm) with lipofuscin-related fundus autofluorescence (FAF; excitation 488 nm, emission > 500 nm) in patients with idiopathic choroidal neovascularization (ICNV). Methods: FAF, NIA, fundus fluorescein angiography (FFA) and indocyanine green angiography.(ICGA).were obtained using a confocal scanning laser Ophthalmoscope HRA2 (Heidelberg Retina Angiograph 2).in 18 eyes of 18 patients with ICNV. Results:.Eighteen eyes had classic CNV, and autofluorescence imaging showed hypoautofluorescence at the site of CNV..A well-defined hyperautofluorescent ring was detected surrounding the CNV in all 18 eyes with NIA imaging. In our sample,.the FAF patterns around the CNV were classified as normal (n=1,.5.56%), well-defined hyperautofluorescent ring (n=7,.38.89%), or ill-defined hyperautofluorescent ring (n=10, 55.56%). Conclusion:.The patterns of FAF and NIA indicated different involvement of lipofuscin and melanin in the pathophysiological process of ICNV. Compared to FAF imaging, NIA imaging appears to be a superior noninvasive method for in vivo visualization of retinal pigment epithelium (RPE) abnormalities in ICNV patients.

Structures and biogenetic analysis of lipofuscin bis-retinoids

Age-related macular degeneration (AMD) is still an incurable blinding eye disease because of complex pathogenic mechanisms and unusual diseased regions.With the use of chemical biology tools,great progress has been achieved in improving the understanding of AMD pathogenesis.The severity of AMD is,at least in part,linked to the non-degradable lipofuscin bis-retinoids in retinal pigment epithelial (RPE).This material is thought to result from the lifelong accumulation of lysosomal residual bodies containing the end products derived from the daily phagocytosis of rod outer segments by RPE cells.Here,we present previously recognized bis-retinoids with focus on structures and biosynthetic pathways.In addition to a brief discussion on the mutual conversion relationships of bis-retinoids,future perspectives and the medical relevance of such studies on these lipofuscin constituents are also highlighted.

Effects of organic solvents on two retinal pigment epithelial lipofuscin fluorophores, A2E and all-trans-retinal dimer

Gene and drug therapies are being developed to al eviate vision loss in patients with Stargardt’s disease and age-related macular degeneration （AMD）. To evaluate the therapeutic effects of these treatments, organic sol-vents are routinely used to extract and quantify bisretinoid lipofuscin constituents, such as N-retinylidene-N-retinyl-ethanolamine （A2E） and all-trans-retinal dimer （ATR-dimer）. By high-performance liquid chromatography （HPLC）, we found that A2E and ATR-dimer were both altered by tetrahydrofuran （THF） and chloroform, but were stable in dimethyl sulfoxide （DMSO） or methanol （MeOH）. In addition, cyclohexane and ethanol （EtOH） did not alter ATR-dimer, whereas an alteration of A2E occurred in EtOH. On the basis of these findings, we designed processes II-IV, generated by modifications of process I, a routine method to measure bisretinoid compounds in vivo. Extra amounts of either ATR-dimer or A2E in mouse eyecups were released by processes II-IV versus process I. Efforts to clarify the effects of organic solvents on lipofuscin pigments are important because such studies can guide the handling of these fluoro-phores in related experiments.

益生菌发酵对姜制天麻活性成分及其抗氧化活性的影响

该文采用产乳酸芽孢杆菌Bacillus sp.DU-106和植物乳杆菌Lactobacillus plantarum复合菌种发酵姜制天麻,对比发酵前后主要活性成分含量变化,并利用体外抗氧化实验和秀丽隐杆线虫模型进一步探讨益生菌发酵姜制天麻抗氧化活性的变化。实验结果显示,经发酵能够显著的提高发酵姜天麻(Fermented Gastrodia elata with ginger,FGEG)的对羟基苯甲醇和总酚含量(P<0.05),分别为5.78 mg/g和10.15 mg/g,两种物质相较于未发酵对照组分别增加了2.54倍和1.74倍。在秀丽隐杆线虫实验中,FGEG能够显著延长正常生长条件下和急性应激条件下线虫的寿命(P<0.01),同时降低线虫体内活性氧自由基含量和提高线虫体内过氧化氢酶活性、谷胱甘肽的含量,并呈现一定剂量依赖效应。同时,FGEG能够显著降低线虫体内MDA的含量和脂褐素相对含量(P<0.001),与空白组相比分别降低了87.21%和82.53%。与未发酵对照组相比,FGEG的体内体外抗氧化活性显著提高(P<0.05)。综上,经发酵后天麻对羟基苯甲醇和总酚含量显著提高,FGEG相较于未发酵样品抗氧化活性显著提升,为FGEG的开发和利用提供理论支撑。

牡蛎提取物对秀丽隐杆线虫的抗衰老作用研究

为了比较牡蛎酶解提取物(enzymolysis extract of oyster,EPO)、牡蛎肽(oyster peptide,OP)和牡蛎水提取物(oyster water extract,WPO)的抗衰老作用,首先进行了基本成分的测定,继而以秀丽隐杆线虫(Caenorhabditis elegans)为动物模型,研究3种牡蛎提取物对线虫的寿命、生殖、脂褐素积累、运动能力、急性氧化应激损伤及体内氧化还原水平等指标的影响。结果表明,EPO、OP和WPO的基本成分有一定的差异,但主要成分均为蛋白质,其中OP的总蛋白质含量最高,为(66.59±0.57)g/100 g干基;与空白组相比,低中高浓度(50、200、800μg/mL)的EPO、OP和WPO均能延长线虫寿命,但低浓度作用不显著,仅OP能呈浓度依赖性地显著增加线虫的产卵量(P<0.05),最高可增加80.2%;3种提取物均能显著降低线虫体内脂褐素的积累(P<0.05),并呈剂量依赖性,最高可达98.15%;高浓度的3种提取物均能显著改善衰老线虫的运动能力(P<0.05),还能显著提高百草枯损伤线虫的存活率及线虫体内谷胱甘肽过氧化物酶和超氧化物歧化酶活力,降低丙二醛含量(89.2%~98.2%)(P<0.05),其作用大小顺序为OP>EPO>WPO。因此,3种不同牡蛎提取物均表现出抗衰老作用,但作用强度有差异,OP的表现最好,研究结果可为进一步开发牡蛎抗衰老食品提供参考。

Characteristics of normal human retinal pigment epithelium cells with extremes of autofluorescence or intracellular granule count

Background:Cells of the retinal pigment epithelium(RPE)accumulate different kinds of granules(lipofuscin,melanolipofuscin,melanosomes)within their cell bodies,with lipofuscin and melanolipofuscin being autofluorescent after blue light excitation.High amounts of lipofuscin granules within the RPE have been associated with the development of RPE cell death and age-related macular degeneration(AMD);however,this has not been confirmed in histology so far.Here,based on our previous dataset of RPE granule characteristics,we report the characteristics of RPE cells from human donor eyes that show either high or low numbers of intracellular granules or high or low autofluorescence(AF)intensities.Methods:RPE flatmounts of fifteen human donors were examined using high-resolution structured illumination microscopy(HR-SIM)and laser scanning microscopy(LSM).Autofluorescent granules were analyzed regarding AF phenotype and absolute number of granules.In addition,total AF intensity per cell and granule density(number of granules per cell area)were determined.For the final analysis,RPE cells with total granule number below 5th or above the 95th percentile,or a total AF intensity±1.5 standard deviations above or below the mean were included,and compared to the average RPE cell at the same location.Data are presented as mean±standard deviation.Results:Within 420 RPE cells examined,42 cells were further analyzed due to extremes regarding total granule numbers.In addition,20 RPE cells had AF 1.5 standard deviations below,28 RPE cells above the mean local AF intensity.Melanolipofuscin granules predominate in RPE cells with low granule content and low AF intensity.RPE cells with high granule content have nearly twice(1.8 times)as many granules as an average RPE cell.Conclusions:In normal eyes,outliers regarding autofluorescent granule load and AF intensity signals are rare among RPE cells,suggesting that granule deposition and subsequent AF follows intrinsic control mechanisms at a cellular level.The AF of a cell is related to the composition of intracellular granule types.Ongoing studies using AMD donor eyes will examine possible disease related changes in granule distribution and further put lipofuscin´s role in aging and AMD further into perspective.

肉苁蓉总甙对小鼠组织的抗氧化作用

目的：研究肉苁蓉总甙（ＧＣＳ）对小鼠组织的抗氧化作用。方法：采用邻苯三酚自氧化、硫代巴比妥酸（ＴＢＡ）和荧光法，分别测定小鼠心、肝、脑、肾组织中ＳＯＤ活性、ＭＤＡ及脂褐质含量。结果：ＧＣＳ（１２５ｍｇ／ｋｇ，２５０ｍｇ／ｋｇ）组能显著提高脑、肾组织中ＳＯＤ活性，２５０ｍｇ／ｋｇ时提高心、肝组织中ＳＯＤ活性，并显著降低各组织ＭＤＡ及脂褐质含量。结论：结果提示ＧＣＳ能有效地提高机体组织抗氧化能力，防止组织脂质过氧化损伤。

有氧运动对老年小鼠骨骼肌抗氧化能力的影响

以C5 7BL/6J雄性小鼠跑转笼为运动方式 ,研究了从 5月龄开始为期 8个月 (小鼠达 13月龄 )或 15个月 (小鼠达 2 0月龄 )的长期有氧运动对小鼠骨骼肌氧化与抗氧化水平的影响。结果发现 ,小鼠骨骼肌细胞浆GSH -Px活性随增龄而升高 ,CuZnSOD活性在衰老早期升高 ,而后下降 ;脂褐素含量随增龄明显增多。提示衰老过程中自由基生成速率可能增加 ,机体氧化与抗氧化水平失衡。长期有氧运动通过适当的增加机体的氧化应激 ,诱导细胞抗氧化酶的增加 ,削弱自由基对机体的氧化损伤 ,延缓与年龄相关的退行性变的发生。

蜂蜜对小白鼠脂质过氧化影响的研究

目的 研究蜂蜜对成年小白鼠体内脂质过氧化作用的影响。方法 将 4 8只健康成年昆明种小白鼠随机分为A(对照组 )、B(过氧化油组 )、C(浅色蜂蜜组 )、D(深色蜂蜜组 )。A组用蒸溜水 0 3ml/d灌胃 ,B组用过氧化油和蒸馏水按 1∶1比例 0 3ml/d灌胃 ,C组用洋槐蜂蜜与过氧化油按 1∶1混合后 0 30ml/d灌胃 ,D组用枣花蜂蜜与过氧化油按1∶1混合后 0 30ml/d灌胃。测定血清SOD活力、MDA含量及肝脏中脂褐质含量。结果 蜂蜜组MDA含量、脂褐质含量低于过氧化油组 (P <0 0 5 ) ,SOD活力高于过氧化油组 (P <0 0 5 ) ,深色蜂蜜组与浅色蜂蜜组SOD活力、MDA含量无差异 (P >0 0 5 ) ,脂褐质含量两组差异有显著性意义 (P <0 0 5 )。结论 蜂蜜可提高小鼠血清SOD活力 ,降低血清MDA及肝脏脂褐质含量 ,具有一定的抗脂质过氧化作用。

牛蒡根抗衰老作用的实验研究

目的 :探讨牛蒡根的抗衰老作用及其机理。方法 :牛蒡根水煎浓缩灌胃给药 30 d后 ,观察大鼠肝组织、脑组织、血清中超氧化物歧化酶 (SOD)活力、丙二醛 (MDA)、脂褐质含量。结果 :牛蒡根组肝组织、血清中 SOD活力明显提高 (P<0 .0 5 ,P<0 .0 5 ) ;脑组织、血清中 MDA含量明显降低 (P<0 .0 1)。结论 :牛蒡根抗衰老作用的主要作用机制是提高 SOD活性 ,降低 MDA、脂褐质含量。

山药及盾叶薯蓣对家蚕寿命和小鼠LPO、LF的影响

研究了山药稀醇提取物及盾叶薯蓣皂甙对家蚕寿命及老龄小鼠血浆过氧化脂质 (LPO)、肝脏脂褐素 (LF)的影响。结果表明 :(1)山药稀醇提取物能明显提高家蚕的平均寿命 ;(2 )山药稀醇提取物和盾叶薯蓣皂甙能明显降低老龄小鼠血浆LPO和肝脏LF的含量。

淫羊藿有效成分抗氧化作用研究

实验结果发现巫山淫羊藿多糖多相脂质体（ＥＳＰＳ）能明显提高老龄动物红细胞及肝组织中ＳＯＤ的活性，提高老龄小鼠红细胞ＧＳＨＰｘ的活性；能明显降低老龄动物血清及肝组织中ＬＰＯ的含量，降低老龄小鼠心肌脂褐质的含量。

籽粒苋延缓衰老作用的研究

本文以BALB／C小鼠为对象，研究籽粒苋对小鼠七项衰老指标的影响，结果表明籽粒苋可以使血清及肝脏中过氧化脂质（LPO）分别降低12．9％及12．1％（P＜0．01）；显著降低心肌脂褐素（LF）含量达25．4％（P＜0．01）；显著升高血红细胞及肝中超氧化物歧化酶（SOD）活性分别为12．1％和14．5％（P＜0．05或P＜0．01）；还可以明显提高血中谷胱甘肽过氧化物酶（GSH-Px）活性达39．4％（P＜0．01）；显著增加皮肤羟脯氨酸（Hyp含量18．1％（P＜0．01）；对血中过氧化氢酶（CAT）活性可以提高11．8％，与老龄对照组比较，尚未有显著差异。籽粒苋还能显著抑制脑中B型单胺氧化酶（MAO－B）活性29．8％（P＜0．01），同时对肝内MAO－B活性无影响。以上结果证明，籽粒苋能提高体内抗氧化酶活性，抑制脂质的过氧化反应，具有良好的抗衰老作用，是一种理想的功能性食品。

何首乌的抗衰老作用研究

目的探讨何首乌对抗D -半乳糖所致亚急性衰老的机制。方法将小鼠 30只随机分为 3组 :对照组、衰老模型组和何首乌治疗组。衰老模型组、何首乌治疗组用D 半乳糖皮下注射 ,1次 /d ,连续 6周造成小鼠衰老。第 3周时 ,何首乌治疗组给小鼠灌胃何首乌。第 6周末处死。测定不同组织脂褐质 (lipofuscin ,LPF)、Na+ /K+ ATP酶 (Na+ /K+ ATPase)、超氧化物歧化酶 (superoxidedismutase ,SOD)和丙二醛含量。结果何首乌可降低小鼠脑组织和肾组织的LPF含量 ,升高心肌Na+ /K+ ATPase活性和肝脏SOD活性。结论何首乌具有抗衰老作用 。

玫瑰花提取物抗衰老作用的研究

以果蝇为动物模型,对玫瑰花提取物(F_(21))进行抗氧化防衰老的研究.通过大样本、高重复的寿命实验,证明了 F_(21)能显著提高果蝇的平均寿命和最高寿命.用 F_(21)饲养(培养基给药浓度0.2%)果蝇后,其处理组果蝇体内的脂褐素含量明显下降、飞行频率有明显的升高趋势;同时,果蝇体内抗氧化酶 CAT 和 SOD 的活力均有明显提高.

贮藏温度和物料初始含水量对山核桃油脂氧化及类脂褐素生成的影响

以山核桃为研究对象,探讨不同温度和初始含水量对山核桃贮藏过程中油脂氧化、类脂褐素(LFLP)积累、多酚含量及醇提物还原力的影响。结果表明:类脂褐素的积累量随着贮藏时间的延长呈上升趋势,多酚含量及醇提物还原力呈下降趋势。在40℃贮藏时,含水量高(12%和16%)的山核桃原料类脂褐素积累速度略低于含水量低(4%和6%)的山核桃;但贮藏温度为25℃时,含水量高的类脂褐素积累速度高于含水量低的山核桃。油脂初级氧化产物和二级氧化产物与贮藏温度和初始含水量呈现复杂关系,40℃贮藏时,含水量高(12%和16%)的山核桃原料油脂氧化程度低于含水量低(4%和6%)的,但贮藏温度为25℃时,含水量高的油脂氧化程度高于含水量低的。多酚含量随含水量的增加和温度的升高损失速度加快,醇提物的还原力变化规律与此类似。总的来说,较低的贮藏温度和低初始含水量能有效地抑制类脂褐素的生成,延缓山核桃的衰老进程。

蜈蚣延缓衰老作用的研究

蜈蚣水提取物能显著降低大鼠血清中过氧化脂质及肝、脑组织中脂褐质含量，对心脏脂褐质无明显影响；可使红细胞中超氧化物歧化酶和血中谷胱甘肽过氧化物酶活力明显升高；使胸腺和脾脏重量明显增加。

2450MHz微波辐射对大鼠海马长时程增强和脑组织脂褐素的影响

目的探讨微波对学习记忆影响的作用机制。方法对海马诱发电位的长时程增强 (LTP)和脑脂褐素含量进行研究 ,用 2 4 5 0MHz微波理疗机为照射源 ,以大鼠为实验对象 ,分别采用在体海马诱发电位法和分光光度法。结果 1 0 2 5mW/cm2 强度范围内的连续微波 ,可以对弱条件刺激和强条件刺激引发的LTP的群峰电位 (PS)峰值产生抑制作用 ,并存在强度 -效应关系 ,在 2 5mW/cm2 时脂褐素含量显著高于对照组和 1 0mW/cm2 组 (P <0 .0 5 )。结论 1 0 2 5mW/cm2 强度范围内的 2 4 5 0MHz连续微波可以通过抑制海马LTP的生成和脑脂褐素含量增加 ,造成学习记忆损害。