微生物源性抗氧化剂对小鼠抗氧化性能及免疫功能的影响

旨在探究不同剂量的微生物源性抗氧化剂对小鼠抗氧化性能及免疫功能的影响。将60只28日龄雌性昆明小鼠随机分为4组,每组15只。试验组分别以0.5 g/kg bw*d(低)、1.0 g/kg bw*d(中)、1.5 g/kg bw*d(高)的剂量灌喂微生物源性抗氧化剂,每天1次,连续30 d,灌胃容量为0.2 mL/10 g bw*d,对照组灌喂等容量的蒸馏水。30 d后,测定微生物源性抗氧化剂对小鼠抗氧化性能及免疫功能的影响。结果表明,1.0 g/kg bw*d的微生物源性抗氧化剂可以极显著地提高血清中GSH-Px的活力(P<0.01),显著提高T-SOD活力(P<0.05),降低MDA的含量(P>0.05)。而1.5g/kg bw*d的微生物源性抗氧化剂可以极显著地提高血清中IgA的含量(P<0.01)和IL-2水平,以及ConA刺激的脾淋巴细胞转化率(P<0.01),促进脾脏和胸腺的发育(P>0.05)。提示1.0g/kg bw*d的微生物源性抗氧化剂可以显著增强小鼠的抗氧化能力,1.5 g/kg bw*d的微生物源性抗氧化剂可以增强免疫功能。     

鸟苷酸二钠体外抗氧化能力的研究

本文研究了鸟苷酸二钠（GMPNa2）对羟自由基和DPPH&#183;自由基的清除效果,同时建立了H2O2氧化损伤体外培养脾细胞模型,用MTT法检测GMPN％的修复及增殖作用,并分析了GMPNa2对细胞抗氧化体系及抗氧化能力的影响,以评价其抗氧化活性。结果表明：GMPNa2具有剂量依赖性的体外抗氧化和清除活性氧能力,10mmol／LGMPNa2的羟自由基清除能力高达96．644％,但DPPH清除率为6．589％。GMPNa2清除羟自由基与同浓度Vc相近,而其清除DPPH自由基的能力很弱。添加0．5、1、5和10mmol／LGMPNa2均能显著修复H2O2诱导的脾细胞氧化损伤（P〈0．05）,提高总抗氧化能力和抗氧化酶类活力（P〈0．01）。GMPNa2添加量大于1mmol／L时,可显著降低MDA含量（P〈0．01）。说明GMPNa2具有显著的抗氧化作用。     

微生物能力验证样品均匀性试验的研究

目的：对人工制备的微生物能力验证样品进行均匀性试验,验证是否符合能力验证的要求。方法：随机抽取能力验证样品,采用AOAC990.12测试方法,菌落总数的结果经单因素方差分析评价其均匀性。结果：样品D均匀性试验结果为样品间变异较小,样品足够均匀;样品C均匀性试验统计学结果显示样品间差异存在显著性,通过借鉴方法的重复性和再现性的标准差对能力验证总体标准差进行评估,计算Sσ,该值小于能力验证的推荐值,该样品的均匀性可能满足能力验证的对样品要求。     

连翘叶黄酮的体外抗氧化作用

为研究连翘叶黄酮(Forsythia suspenseleaves flavonoids,FLF)的体外抗氧化作用,用水杨酸法研究FLF清除.OH的效果,并测定了FLF对连苯三酚自氧化体系的抑制作用。用硫代巴比妥酸(TBA)法测定了小鼠4种器官及肝线粒体、微粒体中的丙二醛(MDA)含量,用分光光度法测定了小鼠红细胞溶血和肝线粒体膨胀程度。结果表明,FLF可以清除.OH,抑制连苯三酚自氧化,并抑制.OH所致丙二醛的产生,减少红细胞溶血,减轻肝线粒体膨胀程度。说明FLF具有明显的抗氧化活性。     

益智有效抗氧化成分的分离条件的研究

探讨了干柱层析法分离益智渣及益智乙醇提取物的抗氧化成分。实验中采用乙酸乙酯/环己烷(3∶7)、氯仿/甲醇(9∶1)为展开剂依次二次干柱层析分离出抗氧化物质。结果表明,益智渣及益智乙醇提取物均有较强的抗氧化性,益智渣的H2O2清除能力强于益智乙醇提取物。     

金樱子提取液体外抗氧化作用研究

目的:探讨金樱子(Rosa Laevigata Mickx.,RLM)提取液的体外抗氧化活性,以更好的评估金樱子的作用。方法:通过体外实验研究金樱子提取液对羟自由基(-OH)、超氧阴离子(O2-)的清除作用;研究金樱子水提取液对正常大鼠肝、肾组织匀浆脂质过氧化产物丙二醛(Malondialdehyde,MDA)生成的影响以及金樱子水提取液对过氧化氢(H2O2)诱导的红细胞氧化溶血的保护作用。结果:金樱子提取液清除-OH及O2-作用呈现出明显的剂量依赖性,可显著抑制大鼠离体肝、肾组织中MDA的生成,还可以明显抑制H2O2诱导的大鼠红细胞氧化性溶血。结论:金樱子提取液体外具有明显的抗氧化活性。     

抗氧化剂与自由基清除剂对硒性白内障形成的影响

本文观察了8种化合物(抗氧化剂及自由基清除剂)对大鼠亚硒酸钠性白内障的影响。实验分为正常对照组,亚硒酸钠组及药物对抗组。亚硒酸钠组系给13日龄大鼠皮下注射亚硒酸钠(6μmoles/kg体重),间日一次,逐次递增1μmole/kg体重,连续5次,药物对抗组则同时腹腔注射抗氧化剂或自由基清除剂,每日观察并记录白内障的发生频率及程度,实验表明,一些抗氧化剂及自由基清除剂能够有效的对抗亚硒酸钠性白内障的发生发展,其中AC1、AC3及AC3的效果尤为明显。本文的结果为探讨白内障形成机理及防治提供了实验依据。     

山楂原花色素的抗氧化作用研究

本文用比色法测定山楂原色素（Proanthocyanidins from the fruits of hawthorn,HPA)的抗氧化作用,即对羟自由基、超氧负离子的清除作用以及抗脂质过氧化的作用,并且通过细胞学实验验证其对上皮细胞的抗氧化损伤的保护作用。试验表明：山楂原色素有很强的抗氧化作用,其作用在浓度为0．1mg/ml-1.0mg/ml之间随着浓度的增大而增强,对超氧负离子的清除和抗脂质过氧化作用尤为明显。在浓度为1mg/ml时,对羟自由基和超氧负离子的清除率分别为59．8％和90．0％,对细胞氧化损伤的保护率为41．96％;浓度为0．5mg/ml时对脂质过氧化的抑制率达91．9％。试验同时还比较了葡萄籽原花色素（Proanthocyanidins from the fruts of grape,GPA)和Vc的抗氧化作用,结果表明：山楂原花色素与葡萄素（Proanthocyanidins from the fruits of grape,GPA)和Vc的抗氧化作用,结果表明：山楂原色素与葡萄籽原花色素效应相当,并远远高于Vc的效应。     

双酚A对雄性大鼠抗氧化能力影响的初步研究

目的：探讨双酚A（BPA）对成年大鼠抗氧化能力的影响。方法：将健康成年雄性SD大鼠84只随机分为5个双酚A染毒剂量组（200、50、5、0.5、0.0005 mg/kg）和1个对照组,连续灌胃染毒8周,并监测体重变化,染毒结束后测定血浆超氧化物歧化酶（SOD）和谷胱甘肽-过氧化物酶（GSH-Px）含量;此外,提取肝脏组织RNA,用荧光实时定量PCR测定肝脏硫氧还原蛋白过氧化物酶2（prdx2）mRNA的表达水平。结果：随着染毒时间的延长,50 mg/kg及200 mg/kg剂量组的动物体重增长速度逐渐减慢,自4周开始,与对照组相比有显著差异（P〈0.05）;染毒结束时,其体重分别为对照组的90.52%和91.61%（p〈0.05）,而其它低剂量组间则无明显差异;大鼠血浆GSH-Px含量总体上呈下降趋势,且5 mg/kg以上剂量组与对照组相比差别均有统计学意义（p〈0.01）;染毒组血浆SOD水平虽也低于对照组,但无统计显著性;此外,大鼠肝脏组织prdx2 mRNA水平随双酚A剂量增高呈剂量依赖性降低,与对照组相比,其在最低剂量组（0.0005 mg/kg）即有显著差异（p〈0.01）。结论：双酚A可造成大鼠抗氧化酶系统失衡,导致氧化损伤效应,prdx2可能是反映其氧化损伤敏感的生物学标志。     

Antioxidant Enzyme Activities during in vitro Morphogenesis of Gladiolus and the Effect of Application of Antioxidants on Plant Regeneration

Activity of antioxidant enzymes was evaluated during somatic embryogenesis and shoot organogenesis from cultured leaf segments of Gladiolus hybridus Hort. The effect of exogenous antioxidants on somatic embryogenesis and shoot organogenesis has also been monitored. Activity of superoxide dismutase (SOD) gradually increased during somatic embryogenesis. while activities of catalase (CAT) and peroxidase (POX) decreased. In contrast, increase in CAT and POX activity and a concomitant decrease in SOD activity were noted during shoot organogenesis. Exogenous application of antioxidants such as glutathione (GSH), α-tocopherol and ascorbate (AA) inhibited somatic embryogenesis but stimulated shoot organogenesis. The frequency of somatic embryogenesis increased with the addition of H₂O₂. However, H₂O₂ inhibited shoot organogenesis. This revised version was published online in July 2006 with corrections to the Cover Date.     

双酚A 对雄性大鼠抗氧化能力影响的初步研究

目的:探讨双酚A(BPA)对成年大鼠抗氧化能力的影响。方法:将健康成年雄性SD大鼠84只随机分为5个双酚A染毒剂量组(200、50、5、0.5、0.0005 mg/kg)和1个对照组,连续灌胃染毒8周,并监测体重变化,染毒结束后测定血浆超氧化物歧化酶(SOD)和谷胱甘肽-过氧化物酶(GSH-Px)含量;此外,提取肝脏组织RNA,用荧光实时定量PCR测定肝脏硫氧还原蛋白过氧化物酶2(prdx2)mRNA的表达水平。结果:随着染毒时间的延长,50 mg/kg及200 mg/kg剂量组的动物体重增长速度逐渐减慢,自4周开始,与对照组相比有显著差异(P<0.05);染毒结束时,其体重分别为对照组的90.52%和91.61%(p<0.05),而其它低剂量组间则无明显差异;大鼠血浆GSH-Px含量总体上呈下降趋势,且5 mg/kg以上剂量组与对照组相比差别均有统计学意义(p<0.01);染毒组血浆SOD水平虽也低于对照组,但无统计显著性;此外,大鼠肝脏组织prdx2 mRNA水平随双酚A剂量增高呈剂量依赖性降低,与对照组相比,其在最低剂量组(0.0005 mg/kg)即有显著差异(p<0.01)。结论:双酚A可造成大鼠抗氧化酶系统失衡,导致氧化损伤效应,prdx2可能是反映其氧化损伤敏感的生物学标志。     

Micro- and Nanoforaminifera from Abyssal Northeast Atlantic Sediments: A Preliminary Report

Rose Bengal stained benthic foraminifera which pass through a 63 μm mesh (microforaminifera and nanoforaminifera) have been extracted by handsorting the fine sieve residues (> 45 μm, 31 μm, 28 μm, 20 μm, 15 μm) of abyssal sediment samples. The samples were collected using a multiple corer in four areas of the northeast Atlantic between 31° N and 59° N. The abundance of these minute foraminifera varied from 2 specimens per 1 cm² (Madeira Abyssal Plain) to > 110 per 1 cm² (BIOTRANS area). They include a variety of taxa, the most common being certain rotaliid species, hormosinaceans and other multilocular agglutinated forms, the unilocular agglutinated genus Lagenammina, soft-bodied agglutinated sphaeres and flasks (saccamminids and psammosphaerids) and allogromiids. Some specimens are < 63 μm in maximum dimension but others belonging to elongate taxa are longer. Two samples taken 10 cm apart on the Porcupine Abyssal Plain suggest that minute foraminifera may be patchily distributed on a small scale. One sample, which was overlain by substantial amounts of phytodetritus, contained > 100 stained specimens (> 30 per 1 cm²) while the other, in which much less phytodetritus was present, yielded only 10 specimens (2.9 per 1 cm²). This observation suggests that some micro- and nanoforaminifera may flourish in the presence of decaying organic matter, perhaps consuming the associated bacteria. The presence of phytodetritus may also explain why two of our samples from the Madeira Abyssal Plain (MAP) contained an order of magnitude more stained tiny foraminifera than two other MAP samples in which phytodetritus was absent.     

Limited Effectiveness of Antioxidants in the Protection of Yeast Defective in Antioxidant Proteins

Efficacy of several antioxidants in the protection of the yeast Saccharomyces cerevisiae mutants deficient in CuZnSOD and deficient in glutaredoxin 5 to growth restriction induced by oxidants was studied. Ascorbate and glutathione protected the Δsod1 and Δgrx5 mutants against the effects of t-butyl hydroperoxide and cumene hydroperoxide, Δsod1 mutants against oxytetracycline and Δgrx5 mutants against menadione and 2,2′-azobis-(2-amidinopropane). However, Tempol, Trolox and melatonin were much less effective, showing prooxidative effects and, at high concentrations, hampering the growth of the mutants in the absence of exogenous oxidants. These results point to a complication of cellular effects of antioxidants by their prooxidative effects and to the usefulness of cellular tests to evaluate the biological effectiveness of antioxidants.     

Antioxidant activity of wheat extracts as affected by in vitro digestion

Phenolic compounds from soft wheat and its milling fractions were extracted and their in vitro antioxidant activity evaluated. Non-hydrolyzed extracts were prepared by extracting phenolics into distilled deionized water. To make hydrolyzed extracts samples were first subjected to pH adjustments in order to simulate gastrointestinal pH conditions. Total phenolic content (TPC) was determined using Folin-Ciocalteu's procedure. Total antioxidant activity (TAA) was determined using Trolox equivalents antioxidant capacity (TEAC) assay and expressed as Trolox equivalents (TE). Antioxidant activity of wheat extracts was determined using the procedures of inhibition of beta-carotene bleaching, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and inhibition of oxidation of human low density lipoprotein (LDL) cholesterol. The TPC and TAA of wheat extracts tested were significantly increased following hydrolysis. Similarly, the antioxidant activity, as determined by different procedures, was considerably increased when the samples were subjected to simulated digestion conditions.     

Antioxidant activity of thiosulfinates derived from garlic

Garlic extract significantly inhibited the oxidation of methyl linoleate in homogeneous acetonitrile solution, whereas the antioxidant effect of allicin-free garlic extract, prepared by removing allicin by prepared by removing allicin by preparative HPLC, was much lower than that of the garlic extract. These results suggest that the antioxidant properties are mostly attributed to the presence of allicin in the garlic extract. Allicin a major component of the thiosulfinates in garlic extract, was found to be effective for inhibiting methyl linoleate oxidation, but its efficiency was less than that of alpha-tocopherol. Next, the reactivity of allicin toward the peroxyl radical, which is a chain-propagating species, was investigated by direct ESR detection. The addition allicin to 2,2'-azobis(2,4-dimethylvaleronitrile)-peroxyl radical solution caused the signal intensity of the peroxyl radical to dose-dependently decrease, indicating that allicin is capable of scavenging the the peroxyl radical and acting as an antioxidant. Finally, we studied the structure-anioxidant activity relationship for thiosulfinates and suggested that the combination of the allyl group (-CH2CH=CH2) and the -S(O)S- group is necessary for the antioxidant action of thiosulfinates in the garlic extract. In addition, one of the two possible combinations, -S(O)S-CH2CH=CH2, was found to make a much larger contribution to the antioxidant activity of the thiosulfinates than the other, CH2=CH-CH2-S(O)S-.     

Influence of Antioxidants on the Peroxidative Swelling of Mitochondria in vitro

To clarify the role of prooxidative processes during in vitro swelling of freshly isolated rat liver mitochondria, the influence of different antioxidants and free-radical scavengers was tested. Ascorbate below 10 mmol/L without externally added Fe²⁺ acted as a prooxidant and enhanced swelling. Higher concentrations in the presence of Fe²⁺ showed antioxidant properties and a decrease in swelling and lipid peroxidation. Swelling was abolished by -tocopherol and reduced to 50% by butylated hydroxytoluene. Glutathione supplementation decreased both swelling and lipid peroxidation. Oxidized glutathione caused swelling without any effect on peroxidation. Hydrogen peroxide, cumene hydroperoxide and t-butyl hydroperoxide caused progressive decreases in glutathione and reduced niacinamide coenzyme levels, suggesting prooxidative changes. Dithiothreitol was found to abolish this effect. Thus, antioxidants reverse superoxide-induced mito chondrial swelling and lipid peroxidation in vitro.     

抗氧化剂对皮肤角质细胞体外寿命的影响

考察了抗氧化剂对鼠角质细胞体外培养寿命的影响。实验发现在角质细胞的体外培养过程中添加抗氧化剂有利于延长细胞的寿命,其中效果最好的是巯基乙醇,其次为过氧化氢酶和SOD,但在体外培养过程中,角质细胞生长速率仍然逐渐下降。实验还发现,添加抗氧化剂可在一定程度上提高角质细胞的克隆形成率,减缓细胞衰老速率。同时,通过考察鼠表皮角质细胞衰老动力学,获得了对应于不同抗氧化剂的细胞衰老动力学常数。 