玫瑰花渣总黄酮清除活性氧自由基及体外抗氧化活性研究

以玫瑰花渣为原料,将超声波技术和双水相萃取技术耦合用于提取玫瑰花中总黄酮,利用Fenton反应产生羟自基·OH,光照核黄素产生超氧阴离子自由基·O-2,采用分光光度法研究玫瑰花渣提取物体外清除活性氧自由基的作用;用硫代巴比妥酸(TBA)分光光度法研究玫瑰花对·OH诱发卵磷脂脂质过氧化抑制作用。结果表明:玫瑰花渣提取物能有效清除活性氧自由基,对卵磷脂脂质过氧化显著抑制作用。     

山药多糖及其硒多糖抗氧化性的比较研究

目的:比较山药多糖和山药硒多糖的抗氧化活性。方法:采用邻苯三酚自氧化法测定两者对超氧阴离子自由基的清除作用,水杨酸法测定羟自由基清除作用,HPLC法测定DPPH浓度评价对DPPH自由基的清除作用,并与维生素C进行了比较。结果:山药多糖、山药硒多糖和Vc对超氧阴离子自由基清除的IC50值分别为1.852 mg/ml、1.515 mg/ml和0.6124 mg/ml。对羟基自由基清除IC50值分别为1.130 mg/ml、0.988 mg/ml和0.075 mg/ml;对DPPH基清除的IC50值分别为0.68 mg/ml、0.62 mg/ml和0.33 mg/ml。结论:山药硒多糖比山药多糖的抗氧化活性强。     

广枣提取物体外清除活性氧自由基及抗氧化作用研究

利用Fenton反应产生羟自由基.OH,光照核黄素产生超氧阴离子自由基O.-2,分光光度法研究了广枣提取物体外清除活性氧自由基的作用。用硫代巴比妥酸(TBA)分光光度法研究广枣提取物对.OH诱发卵磷脂脂质过氧化损伤的抑制作用。实验结果表明,广枣提取物能有效清除活性氧自由基,对卵磷脂脂质过氧损伤有显著抑制作用。     

草苁蓉多糖红细胞保护作用

目的 研究草苁蓉多糖( BRPS)的红细胞保护作用.方法 常规方法提取BRPS,以硫酸亚铁-水杨酸法测定BRPS对羟基自由基(·OH)的清除能力;以硫代巴比妥酸(TBA)法检测BRPS对红细胞抗脂质过氧化的影响,以分光光度法检测BRPS对红细胞溶血的影响.结果 BRPS具有清除羟基自由基能力,浓度小于0.25 mg/mL时,回归方程为y=170.8x+9.5645,R2=0.993;呈明显浓度依赖性,其对·OH的半数清除浓度为0.24 mg/mL;BRPS明显抑制红细胞脂质过氧化作用和减少红细胞溶血程度,其对·OH诱导的红细胞及纯化红细胞膜体系脂质过氧化作用的半数抑制浓度分别为0.047和0.112 mg/mL,对·OH诱导的红细胞溶血的半数抑制浓度分别为0.068 mg/mL.结论 BRPS具有抗脂质过氧化和红细胞保护作用.     

响应面优化黄皮叶中的活性因子超声提取工艺及其抗氧化活性研究

目的优化黄皮叶中活性因子总黄酮的超声提取工艺条件,并测定其抗氧化活性。方法以乙醇体积分数、超声时间及料液比为影响因子,以黄皮叶总黄酮得率为评价指标,在单因素试验基础上,采用响应面法优选黄皮叶总黄酮超声提取工艺,并测定黄皮叶总黄酮体外清除1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-1-picryl hydrazyl,DPPH)自由基、羟自由基和总抗氧化的活性。结果黄皮叶总黄酮的最佳提取工艺条件为乙醇体积分数18%、超声时间73 min、料液比31∶1(m L/g)。在此条件下,黄皮叶总黄酮得率达到(1.300±0.006)%。黄皮叶总黄酮得率大小的主次因素为乙醇体积分数>超声时间>料液比,其中超声时间与料液比因素之间的交互作用显著。黄皮叶总黄酮体外清除DPPH和羟自由基的IC50值分别为0.282 mg/m L、1.152 mg/m L,用三价铁还原抗氧化能力(ferric-reducing antioxidant power,FRAP)法测得1 mg/m L黄酮的FRAP值为533.3μmol/L。结论该所选工艺合理、可行,可用于黄皮叶总黄酮的超声提取;三种测定方法均说明黄皮叶总黄酮在一定浓度下有抗氧化活性。     

蛋清蛋白酶解物抗氧化与血管紧张素转换酶抑制活性的研究

目的研究三种蛋白酶的蛋清蛋白酶解物(EWPH)的抗氧化及血管紧张素转换酶(ACE)抑制活性。方法分别采用Fenton体系、邻苯三酚自氧化体系和亚油酸自氧化体系测定胰蛋白酶、木瓜蛋白酶及alcalase碱性蛋白酶的EWPH清除羟自由基、超氧阴离子及抑制脂质过氧化的能力。利用高效液相色谱法测定ACE抑制活性。超滤分离上述三种蛋白酶的EWPH,检测各组分的抗氧化和ACE抑制活性。结果抗氧化活性最强的是木瓜蛋白酶的EWPH,在浓度10mg/ml时,对羟自由基和超氧阴离子清除率分别为53.14%和27.87%,在浓度0.8mg/ml时,对亚油酸自氧化的抑制率73.72%(D7)。ACE抑制效果最明显的是胰蛋白酶的EWPH,其IC50值为0.985mg/ml。低分子量(Mw3ku)组分酶解物的活性优于高分子量(Mw3ku)组分。结论三种蛋白酶的EWPHs均具有抗氧化和ACE抑制活性,但两种活性之间无明显的相关,且小分子组分的活性最强。     

番石榴叶提取物对小鼠肝脏抗氧化作用研究

目的研究番石榴叶提取物抗氧化活性。方法干燥的番石榴叶分别用蒸馏水、65%和95%乙醇浸提,浸提液过滤、浓缩、干燥得到3种提取物。测定各提取物对羟自由基清除率和脂质过氧化抑制率。紫外分光光度法分析提取物中总黄酮含量,高效液相色谱(HPLC)和紫外可见吸收光谱法(UV)对黄酮类化合物初步鉴定。结果水、65%和95%乙醇提取物均具有清除羟自由基和抑制脂质过氧化作用,且呈剂量-效应关系,对羟自由基清除作用的半数有效浓度(EC50)分别为0.63、0.47和0.58g/L,对脂质过氧化抑制作用的半数有效浓度(EC50)分别为0.20、0.035和0.18g/L,总黄酮含量分别为3.28、30.71和55.98g/kg。结论番石榴叶水和乙醇提取物具有较强的抗氧化作用,其中黄酮类化合物可能是其功效成分之一。     

葡多酚对活性氧自由基的清除作用研究

目的 :　探讨葡多酚 ( GPC)对活性氧自由基的清除作用。方法 :　采用电子自旋共振 ( ESR)和自旋捕集技术直接测定不同浓度 GPC对 Fenton反应体系产生的羟自由基 (· OH)、光照核黄素 /EDTA体系产生的超氧阴离子 ( O·2 )及 Fe2 + 启动线粒体膜脂质过氧化产生的脂类自由基 ( LOO· )清除作用。结果 :　 GPC浓度为 1 mg/L、1 0 mg/L、1 0 0 mg/L、1 0 0 0 mg/L对·OH的清除率 ( % )依次为 9.0、2 0 .6、47.7、57.7,对 O·2 的清除率 ( % )分别为 1 0 .9、1 7.0、50 .9、72 .1 ,对LOO·的清除率 ( % )依次为 39.8、49.6、65.9、71 .4。葡多酚对· OH、O·2 及 LOO· 50 %的清除浓度 ( IC50 值 )分别为 1 2 8.9mg/L、89.4mg/L、1 0 .4mg/L。结论 :　葡多酚对三种活性氧自由基均有不同程度的清除作用 ,其中 LOO· >O·2 >· OH。     

对海参糖胺聚糖抗氧化性的研究

目的研究海参糖胺聚糖的抗氧化性。方法以K3[Fe（CN）6]为模型,测定海参糖胺聚糖的还原能力。利用邻苯三酚自氧化产生超氧阴离子自由基（·O^2-）且在320nm处有最大吸收,测定海参糖胺聚糖对羟自由基（·OH^-）和超氧阴离子自由基（·O^2-）的清除能力。结果海参糖胺聚糖有较强的还原力,对羟自由基和超氧阴离子自由基的清除能力与浓度成量效关系,有良好的清除羟自由基和超氧阴离子自由基的作用。结论海参糖胺聚糖具有良好的抗氧化作用。     

纯化前后海藻硫酸多糖体外清除自由基的电子自旋共振技术研究

目的对比研究纯化前后海藻硫酸多糖(sulfated polysaccharide from Laminaria japonica,SP)体外自由基清除作用。方法按照不同反应体系分别产生羟自由基·OH、超氧阴离子自由基O2·-与脂质自由基RO·,分别在各体系中加入纯化前后SP,采用电子自旋共振技术(electron spin resonance,ESR)对比研究其自由基清除作用。结果纯化前SP 1.25mg/ml对·OH的清除率为60.78%,但随浓度增加清除作用明显减小;0.8mg/ml基本能够全部清除O2·-;对RO·清除作用不明显。纯化后,SP在一定浓度范围内对·OH的清除作用呈量效关系,12mg/ml基本能全部清除O2·-,4 mg/ml对RO·的清除率为23.65%。结论纯化前低浓度SP虽表现活性氧(ROS)自由基清除作用,但由于成分复杂,其机制难以解释;纯化后SP成分均一性提高,具有一定的ROS和RO·清除作用。     

石榴籽提取物体外抗氧化活性研究

目的研究石榴籽提取物的体外抗氧化作用。方法采用普鲁士蓝法、邻二氮菲-Fe2+氧化法和邻苯三酚自氧化法分别测定石榴籽提取物的总抗氧化能力、石榴籽提取物对羟自由基(.OH)和超氧阴离子(.O2-)的清除作用,并与维生素C抗氧化活性相比较。结果石榴籽提取物对.OH和.O2-具有很强的清除作用,其IC50分别为0.157和0.027mg/ml,与维生素C抗氧化作用相似。结论石榴籽提取物具有较强的清除自由基能力,是一种天然有效的抗氧化剂。     

Radical scavenging, antibacterial, and antiproliferative activities of Melissa officinalis L. extracts

The aromatic herb Melissa officinalis L. can be used as an easily accessible source of natural antioxidants and as a possible food supplement and as a phytochemical. Radical scavenging, antibacterial, and antiproliferative activities of petroleum ether, chloroform, ethyl acetate, n-butanol, and water extracts of M. officinalis L. extracts were investigated. The results of antioxidative activity, obtained by electron spin resonance spectroscopy, confirmed that investigated extracts suppressed the formation of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, and lipid peroxyl radicals in all investigated systems in a dose-dependent manner. The maximum DPPH and hydroxyl radical scavenging activities (SA(DPPH) = SA(OH) = 100%) were achieved in the presence of n-butanol extract at concentrations of 0.4 mg/mL and 0.5 mg/mL, respectively. The highest lipid peroxyl scavenging activity (93.20%) was observed at a higher concentration (5 mg/mL) of n-butanol extract in the lipid peroxidation system. The most effective antibacterial activities were expressed by petroleum ether and ethyl acetate extracts on Sarcina lutea. Chloroform extract showed the strongest antiproliferative effect with 50% inhibitory concentration values of 0.09 mg/mL and 0.10 mg/mL for HeLa and MCF-7 cell lines, respectively. The present study demonstrated the high phenolic content and radical scavenging, antibacterial, and antiproliferative activities of extracts of M. officinalis L. originating from Serbia.     

Antioxidative activity of hen egg ovalbumin hydrolysates

To evaluate the antioxidative activity of the hydrolysates of ovalbumin, the antioxidative activities of the enzymatic extracts were evaluated using three different methodologies scavenging assays such as superoxide anion, hydroxyl radical, and inhibitory oxidation of linoleic acid in vitro, and the activities of SOD, GSH-PX, CAT and the level of MDA were determined in serum and liver of aged mice induced by G-gal. The results showed that the hydrolysates had a distinctly inhibitory action to superoxide anion made by alkaline pyrogallic acid, HO. produced by Fenton reaction, the oxidation of linoleic acid in linoleic acid autoxidation system, and presented a positive correlation. The inhibition capacity of hydrolysates against superoxide anion and HO. were more than 45% and 56% respectively at the concentration 5 mg/mL. And the hydrolysates could significantly (p< 0.01) prevented the activities of SOD, GSH-Px, and CAT against reducing and all three concentrations could significantly (p< 0.01) decrease the MDA contents in the serum and liver of aged mice induced by G-gal. The antioxidative activity of high concentration was similar to that of control group.     

Antioxidant capacity of crude extracts from clones of banana and plane species

Banana and plane are the most important fruits in world trade, behind citric plants. In this work we studied the antioxidant capacity of banana and plane varieties of fruits obtained from interspecies crossed varieties of Musa acuminata and Musa balbisiana, named Harton plane, Cavendish banana, and Manzano banana. With this purpose we evaluated banana and plane crude extracts using the ferrous ion oxidation with xylenol orange method, the thiobarbituric acid method, determination of antioxidant activity, and effect on superoxide anion and hydroxyl radical and the radicals generated by ultraviolet light. The experiments showed that all extracts have the capacity to decrease the concentrations of lipid hydroperoxides and malondialdehyde, produced in the lipid peroxidation process, in a manner comparable to that of other widely studied antioxidants like melatonin and vitamin E. Moreover, all extracts had the capacity to inhibit the generation of superoxide anion, hydroxyl radical, and the radicals generated by ultraviolet light. When antioxidant activity was calculated, a value was found that was equivalent to a concentration of uric acid between 0.20 and 0.30 mM at the highest concentration of extract used, with uric acid being a potent antioxidant at 1 mM.     

Anti-oxidant, anti-glycant, and inhibitory activity against α-amylase and α-glucosidase of selected spices and culinary herbs

Aqueous and methanol extracts of dry sage, rosemary, basil, parsley, chili, garlic and onion were analyzed to investigate their anti-oxidant and anti-glycant activities and in vitro inhibitory potential against enzymes involved in glycemic regulation. The aqueous extracts of rosemary and sage were the richest in phenolic compounds and showed the highest ability in binding iron and inhibiting DPPH, superoxide radicals and advanced glycation end-product production, lipid peroxidation, and the activity of α-glucosidase and α-amylase. On the other hand, the methanol extracts of both these Labiatae were less efficient than those of garlic, onion, parsley and chili in scavenging hydroxyl radicals. As far as protein glycation is concerned, methanol extracts were more effective in inhibiting the production of Amadori compounds and the aqueous ones in preventing advanced glycation end-product formation. Therefore these spices may be preventive not only against cardiovascular diseases but also type 2 diabetes.     

荞麦蛋白和类黄酮提取物清除自由基的ESR研究

目的:探讨荞麦蛋白质提取物(BWPr)和类黄酮提取物(BWF)清除活性氧自由基的作用。方法:采用电子自旋共振(ESR)及自旋捕获技术。结果:BWPr可清除O2,且呈明显的量效关系,在1.4～_?6.0mg/ml浓度范围内,随着蛋白液浓度的增加,清除率近乎直线升高,而再增加蛋白液的浓度,清除率增加幅度下降,甜荞蛋白和苦荞蛋白的IC50分别为4.1mg/ml、3.2mg/ml。而BWF清除O2的作用高于_?甜荞蛋白和苦荞蛋白,当其浓度为58mg/L时清除率就达77.89%,而浓度为293mg/L时清除率达到98.56%。BWPr对·OH也有一定的清除效果,但不及BWF。结论:BWPr和BWF都有清除活性氧自由基的作用,提示除荞麦类黄酮外,荞麦蛋白质也是一种自由基清除剂。     

Antioxidant activity of methanolic extract of emblica fruit (Phyllanthus emblica L.) from six regions in China

The phenolic contents of methanolic extracts of emblica (Phyllanthus emblica L.) fruit from six regions in China were measured in this work. The antioxidant activities of these extracts were also evaluated. Total phenolic content was ranged from 81.5 to 120.9 mg gallic acid equivalents (GAE)/g and the flavonoid content was varied from 20.3 to 38.7 mg quecetin equivalents (QE)/g, while proanthocyanidin content was ranged from 3.7 to 18.7 mg catechin equivalents (CE)/g. Among all the methanolic extracts analyzed, the Huizhou sample exhibited a significantly higher phenolic content than other samples (P<0.05). The antioxidant activities were evaluated by in vitro experiments using scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, hydroxyl radicals, and superoxide anion radicals, chelating ability of ferrous ion, reducing power, and inhibition capability of Fe (II)-induced lipid peroxidation, respectively. The Huizhou sample was found to have the strongest antioxidant activities in scavenging DPPH radicals, superoxide anion radicals, and had the highest reducing power, while the Chuxiong sample showed the best performance in chelating iron and inhibiting lipid peroxidation. Furthermore, the Chuxiong sample exhibited a stronger inhibition activity of the hydroxyl radicals compared with other samples. The high correlation coefficient was existed between the phenolic content and superoxide anion radical scavenging activity, but no significant correlation was found between the former and hydroxyl radical scavenging activity. Methanolic extracts of emblica fruit from some selected regions exhibited stronger antioxidant activities compared to those of the commercial compounds (quercetin and BHA). It might be considered as a potential plant source of antioxidants.     

Resistance of Lactobacillus plantarum KCTC 3099 from Kimchi to oxidative stress

The antioxidative capacity of two lactic acid bacteria isolated from Kimchi, a Korean fermented food, was evaluated by measuring the resistance to reactive oxygen species (ROS) and compared with that of Lactobacillus rhamnosus GG as a positive control. Both intact cells and cell-free extracts of Lactobacillus plantarum KCTC 3099 exhibited higher antioxidative activity in inhibiting lipid peroxidation among the strains evaluated with an inhibitory level of 38.6% and 48.5%, respectively. To evaluate the resistance of the two lactic acid bacteria to ROS, we tested their survival in the presence of 1 mM hydrogen peroxide, 0.4 mM hydroxyl radicals, and superoxide anions induced by 10 mM paraquat. L. plantarum KCTC 3099 was viable even after 8 hours in the presence of both 1 mM hydrogen peroxide and 0.4 mM hydroxyl radicals. Moreover, the survival of L. plantarum KCTC 3099 was not affected by superoxide anions generated by using paraquat, indicating that it has resistance to superoxide anions. To define the antioxidative mechanism, superoxide dismutase (SOD) and metal ion chelating activities were determined. L. plantarum KCTC 3099 presented little SOD activity, but had the higher level of chelating activity for both Fe2+ and Cu2+ metal ions at 13.6 ppm and 23.9 ppm, respectively. These results suggested that the antioxidative capacity of L. plantarum KCTC 3099 is apparently caused by chelating metal ions rather than by SOD activation.     

Evaluation of in vitro antioxidant activity of Sida rhombifolia (L.) ssp. retusa (L.)

Sida rhombifolia (L.) ssp. retusa (L.) is widely used in Ayurvedic medicine for the treatment of fever as well as a diuretic. The comparative antioxidant potentials of ethanol extract of roots, stems, leaves, and whole plant were studied. Estimation of total polyphenolic content and high-performance thin-layer chromatography profile were determined. Further inhibition of oxygen-derived free radicals, viz., assays for free radical scavenging, reducing power, superoxide anion scavenging, nitric oxide scavenging, and anti-lipid peroxidation, were performed. All the antioxidant activities were compared with standard antioxidants such as butylated hydroxyanisole and alpha-tocopherol acetate. Extracts were found to be good scavengers of the 1,1-diphenyl-2-picrylhydrazyl radical in the order root > leaves > whole plant > stem with 50% inhibitory concentrations of 546.1, 852.8, 983.8, and 1,222.5 microg/mL, respectively. All extracts of this plant showed effective free radical scavenging activity, reducing power, and superoxide scavenging activity. Only root extract inhibited lipid peroxidation in rat liver and brain homogenate. All these antioxidant properties were concentration dependent. In addition, total polyphenolic contents of all the extracts were determined as gallic acid equivalents. The highest antioxidant activity was observed in root extract. The results obtained from the current study indicate that S. rhombifolia ssp. retusa is a potential source of natural antioxidants.