凤仙花不同部位乙醇提取物多酚、黄酮含量测定及抗氧化活性研究

采用55%的乙醇分别回流提取凤仙花的茎、叶、花中的活性物质,采用比色法测定各部位的多酚及总黄酮含量,测定各提取物对DPPH、羟自由基、超氧阴离子自由基的清除能力和还原力等抗氧化活性指标。结果表明,凤仙花各部位的多酚(以没食子酸计)、总黄酮(以芦丁计)含量由高到低依次为凤仙花的叶、花、茎,多酚含量分别为72.81、66.07、33.07 mg/m L,总黄酮含量分别为112.13、108.06、30.62 mg/m L。各种提取物均有不同程度的抗氧化活性,且抗氧化活性与提取物浓度存在量效关系,其中叶提取物清除DPPH自由基、羟自由基、超氧阴离子自由基活性以及还原力均最高,本研究为凤仙花作为低毒高效的天然抗氧化剂应用提供了依据。     

沙棘茶水溶性多糖抗氧化活性的研究

通过还原力、清除超氧阴离子自由基、清除羟自由基和抑制H2O2诱导红细胞氧化溶血实验来评价沙棘茶水溶性多糖(WPHT)体外抗氧化能力,并与Vc进行了比较.结果表明,WPHT具有较强的还原能力,对O-·2和·OH具有较强的清除作用,IC50分别为:394 μg/mL、182 μg/mL;对H2O2诱导红细胞氧化溶血及MDA生成有很强的抑制作用,IC50分别为:221 μg/mL、202 μg/mL.说明WPHT在一定浓度范围内具有较强的抗氧化能力.     

散沫花叶总黄酮、多酚含量测定及体外抗氧化活性研究

用55%乙醇回流提取散沫花叶中的活性物质,采用比色法测定提取物中的总黄酮及多酚含量,测定了其对DPPH、羟自由基、超氧阴离子自由基的清除能力和还原力等抗氧化活性指标。结果表明,散沫花叶提取物中的总黄酮(以芦丁计)、多酚(以没食子酸计)含量分别为39.42 mg/g、116.20 mg/g,提取物具有一定的抗氧化活性,且抗氧化活性与提取物浓度存在量效关系,本研究为散沫花叶作为低毒高效的天然抗氧化剂应用提供了依据。     

西藏红景天提取物延长线虫寿命和抗氧化活性探索

探讨红景天苷和西藏红景天粗提物对延长线虫寿命的影响及其体外抗氧化活性的比较。以红景天苷、红景天粗提物为研究对象、以Vc为阳性对照,分别检测以上三种物质对自由基的清除作用。结果表明红景天能够显著延长秀丽隐杆线虫的寿命;在相同浓度下,红景天苷清除DPPH自由基的EC50约为1291.53μg/mL,红景天提取物溶液约为489.76μg/mL;红景天苷清除羟自由基的EC50约为1120.94μg/mL,红景天提取物约为1068.37μg/mL;红景天苷清除超氧阴离子自由基的EC50约为55.57μg/mL,红景天提取物溶液约为40.49μg/mL。中药红景天中含有显著延长线虫寿命的抗氧化物质,而这种成分并非是红景天苷。     

微生物源性抗氧化剂体外抗氧化能力的初步研究

目的:研究微生物源性抗氧化剂的体外抗氧化能力.方法:在体外分别测定微生物源性抗氧化剂、α-生育酚(Vε)、抗坏血酸(VC)、L-硫辛酸、表没食子酸儿茶素的还原能力,羟自由基、超氧阴离子自由基和DPPH自由基清除能力及抗脂质过氧化能力,比较微生物源性抗氧化剂与其他抗氧化剂抗氧化能力.结果:微生物源性抗氧化剂有较强的抗氧化能力,体外清除羟自由基、超氧阴离子自由基、DPPH自由基能力的半数有效量(EC50)分别为184.5μg、48.7μg、66.1 μg.与常见抗氧化剂相比,微生物源性抗氧化剂对氧自由基及氮自由基都有较好的清除自由基作用.结论:微生物源性抗氧化剂体外抗氧化作用明显,有进一步开发的价值.     

家蝇幼虫提取物清除氧自由基的作用

探讨了家蝇Musca domesticaL.幼虫提取物对氧自由基的清除作用。采用脱氧核糖-铁体系和邻苯三酚自氧化体系分别测定了不同浓度的提取物对羟自由基和超氧阴离子自由基的清除率,同时采用H2O2氧化体系测定了提取物的抗氧化值。结果显示家蝇幼虫提取物对羟自由基和超氧阴离子自由基的IC50分别为1.93 mg/mL和3.26 mg/mL;浓度为0.5%的提取物的抗氧化值为9.01 mg/g,为同浓度维生素C抗氧化值的1.29倍。     

南瓜醇提物的体外抗氧化活性(英文)

采用化学体系模拟法体外测定南瓜醇提物((pumpkin ethanol extract,PEE)对1,1-二苯基-2-苦苯肼自由基(DPPH·)、超氧阴离子自由基(O2)和羟自由基(·OH)的清除能力,总还原力,对β-胡萝卜素/亚油酸自氧化体系的总抗氧化能力以及脂质过氧化的抑制能力.结果显示PEE对DPPH·、02-和·OH均有较强的清除能力,IC50值分别为18.8 mg/mL、29.0 ms/mL和44.9μg/mL,有显著的还原力和总抗氧化力,对脂质过氧化有一定的抑制作用.PEE的体外抗氧化活性均有良好的量效关系.上述结果为南瓜作为抗氧化的保健食品或功能食品开发利用提供了依据.     

樟子松乙醇提取物体外抗氧化活性研究

测定了樟子松球果、树皮、树叶、木质部4个部位提取物的总抗氧化能力、总还原力、二苯代苦味酰基（DPPH·）清除能力、羟基自由基（·OH）清除能力、超氧阴离子（O^·₂）清除能力5个指标,并以抗坏血酸（Vc）为阳性对照评价从樟子松4个部位提取的松多酚体外抗氧化活性。结果表明：（1）从樟子松树皮中提取的樟子松多酚表现出较强的抗氧化能力,在较高浓度下与抗氧化剂（Vc）相差较小;从樟子松球果中提取的樟子松多酚也表现出较强的还原力,甚至超过阳性对照抗氧化剂Vc;（2）从樟子松树皮中提取的樟子松多酚在二苯代苦味酰基（DPPH·）清除能力、羟基自由基（·OH）清除能力上均为三者之中最高的,但都不超过抗氧化剂（Vc）的抗氧化能;（3）超氧阴离子（O^·₂）清除能力。三者的清除率均为负值,说明该方法测定超氧阴离子（O^·₂）清除率存在干扰因素,无法比较三者在这一指标上的能力大小。上述结果表明樟子松乙醇提取物具有较强的抗氧化能力,可作为天然的抗氧化剂。     

两株乳酸杆菌SY13和LJJ对活性氧的耐受性

【目的】从传统发酵乳制品中筛选具有抗氧化能力的乳酸菌菌株并对其抗氧化特性进行评价。【方法】分别利用乳酸杆菌SY13和LJJ完整细胞和无细胞提取物对亚油酸过氧化的抑制效果,对DPPH自由基、羟自由基、超氧阴离子自由基清除能力,对过氧化氢的耐受性以及对亚铁离子的螯合能力和还原活性进行了研究。【结果】结果表明,SY13和LJJ对亚油酸过氧化的最大抑制率分别达到了62.95%和66.16%;两菌株的无细胞提取物清除超氧阴离子和羟自由基的的效果较好,LJJ完整细胞对超氧阴离子和羟自由基没有清除能力;SY13和LJJ对DPPH自由基的清除能力及对亚铁离子的螯合能力都是完整细胞优于无细胞提取物,还原活性分别相当于305 μmol/L和294 μmol/L的L-cysteine。【结论】以上指标测定的结果说明,这两株乳酸杆菌具有较好的抗氧化能力,具有潜在的应用价值。     

褐蘑菇水溶性多糖抗氧化活性研究

采用水提醇沉以及sevag去蛋白的方法获得褐蘑菇水溶性多糖(WPPA)。通过测定还原力、超氧阴离子清除率、羟基自由基清除率和抑制H2O2诱导红细胞氧化溶血实验评价WPPA抗氧化活性。结果表明:WPPA具有较强的还原力,对O2-.和.OH具有较强的清除作用,IC50分别为527μg/mL、310μg/mL;对H2O2诱导红细胞氧化溶血及MDA生成有很强的抑制作用,IC50分别为700μg/mL和541μg/mL。说明WPPA在一定浓度内具有较强的抗氧化能力。     

川芎粗多糖抗氧化和细胞毒活性研究

通过川芎粗多糖(LCP)对DPPH离子、超氧阴离子、.OH、总抗氧化能力、螯合能力、还原性和脂质过氧化能力的抗氧化效果和对肝癌细胞HepG2的抑制作用研究。结果显示:LCP具有较强的还原力,对超氧阴离子自由基、脂质过氧化产物有良好的抑制作用,其对肝癌细胞HepG2也具有一定的抑制作用。LCP有望作为天然抗氧化剂及功能性食品得到开发与应用。     

Antioxidant Activity of Purified Protein Hydrolysates from Northern Whiting Fish (Sillago sihama) Muscle

In the present study, northern whiting fish (Sillago sihama) muscle was hydrolyzed with gastrointestinal enzymes (pepsin, trypsin and α-chymotrypsin) separately and the resulted protein hydrolysates were tested for antioxidant activities using DPPH radical scavenging activity and reducing power assays. The protein hydrolysate obtained from trypsin exhibited highest antioxidant activity. Further, it was fractionated by consecutive chromatography using anion exchange and gel filtration chromatography; the separated fractions were collected and evaluated for antioxidant activity. The results showed that fraction 2 exhibited high chelating activity (73.15 % at 0.5 mg/mL) and best radical scavenging activity for DPPH radical (55.16 % at 0.5 mg/mL), ABTS radical (57.98 % at 50 μg/mL), superoxide radical (39.55 % at 200 μg/mL) and hydroxyl radical (51.33 % at 100 μg/mL). In addition, the active fraction showed strong antioxidant activity in the inhibition of linoleic acid autooxidation (60 % at 0.5 mg/mL) and also it exhibited significant protective effect on DNA damage caused by hydroxyl radicals. The size of the active fraction was found to be <360.2 Da using mass spectroscopy. These results demonstrate that muscle protein hydrolysate from northern whiting fish could be a best alternative to produce natural antioxidant peptides.     

印度块菌提取物抗氧化活性的研究

对印度块菌Tuber indicum子实体的提取物,包括55%乙醇粗提物(ECE)、石油醚提取物(PEF)和乙酸乙酯提取物(EAF)的清除DPPH自由基和羟基自由基能力、铁离子鳌合能力以及各提取物的总酚含量等进行了研究和测定,结果显示,3种提取物的清除自由基能力和铁离子鳌合能力具有显著差异(P0.05);ECE对DPPH自由基的清除活性最高,其EC50值为1.61g/L;EAF对羟基自由基及铁离子表现出较强的清除或螯合的能力,其EC50值分别为3.31g/L和0.70g/L;EAF的总酚含量(2.964mg GAE/g提取物)最高,其次是ECE,总酚含量为(2.618mg GAE/g提取物);PEF的清除自由基和铁离子鳌合能力较差,其总酚含量也最低(1.124mg GAE/g提取物);总酚含量与印度块菌提取物清除自由基以及鳌合铁离子的能力密切相关。     

In vitro antioxidant activity of Hedyotis corymbosa (L.) Lam. aerial parts

The methanolic extract of the aerial part of Hedyotis corymbosa (L.) Lam. (Rubiaceae) was screened for antioxidant activity using 1,1-diphenyl-2-picryl hydroxyl (DPPH) quenching assay, 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid (ABTS) cation decolorization test, ferric reducing power (FRP), scavenging capacity towards hydroxyl ion (OH*) radicals and nitric oxide (NO) radical inhibition activity using established assay procedures. Total phenolics and total flavonoid contents were, also determined. The plant yielded 210 mg gallic acid equivalent/100 g phenolic content and 55 mg quercetin equivalent/100 g flavonoid content. The extract exhibited high antiradical activity against DPPH, ABTS, nitric oxide and hydroxyl radicals with EC50 value of 82, 150, 130, and 170 microg/ml, respectively. The FRP increased with increasing concentration of the sample. The antioxidant activity of the extract was comparable with that of the standard butylated hydroxyl toluene (BHT). High correlation between total phenolic/flavonoid contents and scavenging potential of different reactive oxygen species (R2 = 0.785-0.998) indicated the polyphenols as the main antioxidants.     

Total phenolics, flavonoids and antioxidant activity of Saptarangi (Salacia chinensis L.) fruit pulp

Salacia chinensis L. has various beneficial properties including antidiabetic and antioxidant activity. The S. chinensis fruit pulp (SCFP) was extracted with four different solvents (Methanol, ethanol, acetone and water) and was screened for total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity (AOA). The AOA was assessed by evaluating the 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and metal chelating assay. Methanolic SCFP extract exhibited the highest phenolic content (3.20?±?0.12 mg GAE/g FW) whereas, ethanolic extract showed highest flavonoid content (0.31?±?0.68 mg RE/g FW). The methanolic extract possesses highest antioxidant activity towards DPPH (92.44 %), FRAP (1.939 O.D) and metal chelating activity (74.16 %). AOA (DPPH and FRAP) was significantly correlated with TPC. The results indicated that SCFP is a good natural source of antioxidant compounds for use in food and pharmaceutical industry.     

Phytochemical analysis and evaluation of antioxidant activities of methanolic extracts of Maytenus emarginata

Reactive oxygen species (ROS) is a metabolic side product of oxidative stress process, which causes several diseases like atherosclerosis, cancer, etc. In defense of ROS, antioxidants play a key role in combating them. As the process of aging increases, the level of antioxidants in our body decreases and thereby needs utmost attention for its repair process, which is generally administered externally. Plant products serve a best source for controlling these activities by its own metabolic pathway. Studies on the antioxidant activities of Maytenus emarginata leaf extracts are lacking. Antioxidant activity of the methanol extract of Maytenus emarginata was determined by DPPH free radical nitric oxide scavenging assays, superoxide ion scavenging assays, ABTS, and iron chelating methods. Preliminary phytochemical screening revealed that the extract of Maytenus emarginata leaves possesses phenols, flavonoids, steroids, glycosides, saponins, tannins, and triterpenoids. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant (ascorbic acid) in a dose-dependent manner, and remarkable activities to scavenge ROS may be attributed by the presence of the above active compounds in the leaves. The amount of total phenolics and flavonoid contents were also estimated. The DPPH, ABTS, Nitric oxide, superoxide, and iron chelating IC(50) values of the methanolic extracts were 12.44, 24.27, 22.41, 5.85, and 2.74?μg/mL, respectively. The total phenolic content of the methanolic extract was 10.69?mg CA/g, whereas the total flavonoid was 1.56?mg CAE/g. The antioxidant activities were correlated with the total phenolic content. This result suggests that the relatively high antioxidant activity of the methanolic extract compared to standard could be possibly be due to its high phenolic content.     

Antioxidant and antiradical activities of L-carnitine

L-carnitine plays an important regulatory role in the mitochondrial transport of long-chain free fatty acids. In this study, the antioxidant activity of L-carnitine was investigated as in vitro. The antioxidant properties of the L-carnitine were evaluated by using different antioxidant assays such as 1, 1-diphenyl-2-picryl-hydrazyl free radical (DPPH.) scavenging, total antioxidant activity, reducing power, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities. Total antioxidant activity was measured according to ferric thiocyanate method. alpha-tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference antioxidant compounds. At the concentrations of 15, 30 and 45 microg/mL, l-carnitine showed 94.6%, 95.4% and 97.1% inhibition on lipid peroxidation of linoleic acid emulsion, respectively. On the other hand, 45 microg/mL of standard antioxidant such as alpha-tocopherol and trolox indicated an inhibition of 88.8% and 86.2% on peroxidation of linoleic acid emulsion, respectively. In addition, L-carnitine had an effective DPPH. scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, total reducing power and metal chelating on ferrous ions activities. Also, those various antioxidant activities were compared to alpha-tocopherol and trolox as references antioxidants.     

乌鳖黑色素理化性质及其抗氧化活性研究

本试验以乌鳖肌肉为原料,采用“脱脂-酶解-酸解”三步法制备乌鳖黑色素,研究其结构特性、理化性质和抗氧化活性。采用紫外分光光度计、傅里叶红外光谱仪和元素分析仪对乌鳖肌肉黑色素结构特性进行分析,并进行了颜色检测、溶解性试验、稳定性试验、总抗氧化能力试验、羟基自由基清除能力试验、DPPH自由基清除能力试验、超氧阴离子自由基清除能力试验等理化性质和抗氧化活性检测分析。结果表明:乌鳖黑色素粉末呈黑色(L=45.04),略带红色和黄色(a=1.92,b=5.27);具有与其他黑色素相似的溶解性,溶于碱性溶液,不溶于水、有机溶剂和酸性溶液等;乌鳖黑色素在1 h内具有较强光稳定性和热稳定性;乌鳖黑色素具有较强的抗氧化能力,其中2.0 mg/mL浓度的黑色素溶液羟自由基清除率、超氧阴离子自由基清除率和DPPH自由基清除率均在40%以上。     

青橄榄浸膏的提取及其抗氧化活性研究

为优化青橄榄浸膏提取工艺,并探讨其抗氧化性。以茂名盛产的青橄榄为原料,采用超声波辅助乙醇提取法,以总黄酮和总多酚得率为评价指标,考察各因素对青橄榄浸膏提取效果的影响。采用邻苯三酚自氧化法、结晶紫法和DPPH清除能力评价青橄榄浸膏的抗氧化活性。结果显示,浸膏的最佳提取工艺为:乙醇体积分数70%,料液比1∶18 (g∶mL),超声提取温度50℃,时间6 min(超声提取阶段);单纯有机溶剂提取温度60℃,时间45 min(有机溶剂浸提阶段);此条件下总黄酮得率为1. 76%,总多酚得率为15. 53%。终产物浸膏在0. 3 mg/mL浓度下对超氧阴离子自由基抑制率为22. 74%,相当于同等质量浓度的抗坏血酸抑制效果的23. 47%;在0. 02 mg/mL浓度下对羟基自由基的清除率为67. 32%,相当于同等质量浓度的抗坏血酸清除效果的112. 58%;在0. 2 mmol/mL的DPPH溶液体系中,0. 15 mg/mL的浸膏对DPPH的清除率为95. 40%,相当于同等质量浓度的抗坏血酸清除效果的140. 83%;总体来讲,浸膏具有良好的抗氧化能力,虽然对超氧阴离子自由基抑制率弱于抗坏血酸,但羟基自由基的清除率及DPPH清除率均优于抗坏血酸。