桂花子提取物体外抗氧化和抑菌活性的研究

研究桂花子黄酮和多糖清除DPPH自由基、羟自由基和ABTS+自由基的能力,以及桂花子黄酮对大肠杆菌、金黄色葡萄球菌及枯草芽孢杆菌的抑菌活性,为桂花子提取物的保健功能应用提供理论基础。抗氧化活性试验结果表明：在试验范围内,多糖对DPPH自由基、羟自由基和ABTS+自由基最高清除率分别为55.8%、48.5%、77.9%;黄酮对DPPH自由基、羟自由基和ABTS+自由基最高清除率分别为90.2%、40.3%、93.4%,桂花子黄酮和多糖对DPPH自由基、ABTS+自由基有较强的清除能力,对羟自由基的清除能力较弱。抑菌试验结果表明,桂花子黄酮对金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌皆有抑制作用,对大肠杆菌和金黄色葡萄球菌的最低抑菌浓度为0.5 mg/mL,低于苯甲酸钠的最低抑菌浓度（0.625 mg/mL）;对枯草芽孢杆菌的最低抑菌浓度为0.25 mg/mL;明显低于苯甲酸钠的最低抑菌浓度（1.25 mg/mL）。     

红凤菜花色苷提取物的热降解动力学与抗氧化活性研究

对红凤菜花色苷水提取物的粗提物和纯化物分别进行了热稳定性的研究,并以DPPH法、ABTS法、邻二氮菲-Fe2+法评价了它们的抗氧化活性。结果表明:红凤菜花色苷提取物的热降解遵循一级反应动力学规律。在65～95℃范围内,红凤菜花色苷粗提物和纯化物的半衰期t1/2分别为3.55～1.73 h和26.52～2.92 h,反应活化能Ea分别为45.45 kJ/mol和101.31 kJ/mol。红凤菜花色苷提取物清除不同自由基的能力由大到小依次为羟自由基 DPPH自由基 ABTS自由基,其中对羟自由基清除率优于维生素C对照。粗提物、纯化物和维生素C清除羟自由基的EC50分别为1.17 mg/mL、0.57 mg/mL、2.65 mg/mL,清除DPPH自由基的EC50分别为0.50 mg/mL、0.15 mg/mL、49.50μg/mL,清除ABTS自由基的EC50分别为0.72 mg/mL、0.24 mg/mL、49.62μg/mL。纯化后的花色苷提取物热稳定性和抗氧化活性均优于粗提物。     

牛至精油成分分析及其抗氧化性和抑菌活性研究

该研究采用水蒸气蒸馏法提取牛至精油,利用气相色谱-质谱联用(GC-MS)技术分析牛至精油组成成分。通过测定牛至精油对DPPH·和ABTS+·的清除能力,研究牛至精油的抗氧化活性,并采用抑菌圈法研究牛至精油对大肠杆菌和金黄色葡萄球菌的抗菌性能。结果表明,水蒸气蒸馏法提取牛至精油的提取率为0.15%,GC-MS共检测到54种精油组分,占精油总含量的91.04%,百里香酚(26.63%)、香芹酚(14.44%)、2-异丙基-1-甲氧基-4-甲基苯(11.75%)和松油烯(9.23%)为相对含量较高的成分。牛至精油对DPPH·和ABTS~+·均具有清除能力,对ABTS+·的清除能力远强于对DPPH·的清除能力,其IC50值分别为1.41μg/mL和0.0103μg/mL,抗氧化性比化学合成的抗氧化剂BHT强。牛至精油对大肠杆菌和金黄色葡萄球菌均具有抑菌活性,其抑菌圈直径分别为9.5mm和6.5mm。     

紫苏叶活性成分及抗氧化性研究

研究紫苏叶提取物活性成分及抗氧化性。以乙醇为溶剂浸提紫苏叶活性物质,采用分光光度法测定其活性成分含量,并测定该提取液对羟自由基(·OH)、超氧阴离子自由基(O-2·)及DPPH·有机自由基的清除能力,以VC为阳性对照,比较其抗氧化能力。结果表明,紫苏叶提取物总黄酮含量为32.51%,多糖含量为9.43%,迷迭香酸含量为22.8%。紫苏叶提取物对·OH、O-2·、DPPH·均有一定清除能力,但比同浓度Vc的清除能力弱。     

神经网络优化紫苏叶黄酮微波提取及抗氧化活性比较研究

紫苏是一种珍贵的药食两用植物.为确定紫苏叶黄酮类物质的微波提取工艺,分析其抗氧化活性,采用动量梯度下降神经网络研究微波功率、乙醇体积分数、料液比和提取时间对黄酮提取率的影响,对反应条件进行训练仿真和网络预测.采用DPPH·自由基、羟自由基、超氧阴离子和ABTS+·自由基比较分析紫苏叶的水、醇提取物的抗氧化性质.研究结果表明:经过训练的网络可以很好地模拟微波提取条件,当微波功率480 W,乙醇体积分数80%,固液比1:25g/mL,提取时间25min时,黄酮提取率达6.2mg/g.随着提取物浓度的增大,清除自由基能力增强.高含量(0.5 mL/mL)的紫苏叶醇提物具有良好的清除自由基能力,清除率90%以上.叶水提物对自由基清除能力较差,在其含量为0.5mL/mL时,对DPPH自由基的清除率仅36%.     

大果沙棘总黄酮体外抗氧化和抑菌作用研究

研究大果沙棘总黄酮的体外抗氧化和抑菌活性。采用DPPH和ABTS自由基清除率检测大果沙棘总黄酮体外抗氧化活性;通过测定抑菌圈直径和最低抑菌浓度检测大果沙棘总黄酮的抑菌作用。100μg/m L的大果沙棘总黄酮对DPPH和ABTS自由基的清除率分别为65.1%和92.3%,接近芦丁和儿茶素对照品;抑菌试验结果显示:0.125 mg/m L~1.0 mg/m L的大果沙棘总黄酮对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌有显著的抑菌效果。     

石榴籽多酚的体外抗氧化活性

目的:为拓展石榴籽开发用途,了解其多酚粗提物和纯化物的体外抗氧化活性作用强弱。方法:本实验采用有机溶剂浸提法提取石榴籽中的多酚物质并以有机溶剂萃取法进行纯化,采用ABTS法、邻苯三酚自氧化法、Fenton法和DPPH法测定了石榴籽粗提液及纯化液对ABTS自由基、羟基自由基、超氧阴离子和DPPH自由基的清除能力。结果表明,石榴籽中的多酚粗提液和纯化液对ABTS、DPPH自由基均有较强的清除能力,而对超氧阴离子自由基和羟基自由基的清除能力较弱;多酚粗提液清除ABTS、DPPH自由基的IC₅₀值分别为37.13 191.82 μg/mL,多酚纯化液清除ABTS、DPPH自由基的IC₅₀值分别为29.11、143.26 μg/mL;纯化液对ABTS自由基、羟基自由基及DPPH自由基的清除能力强于粗提液。     

青麦仁麸皮中阿魏酸的抗氧化性和抑菌活性研究

通过铁离子还原法、DPPH自由基清除法、羟基自由基清除法、ABTS自由基清除法来探索阿魏酸的体外抗氧化活性;采用试探性试验与牛津杯法、琼脂培养基稀释法和液体培养法分别测定青麦麸阿魏酸对部分食品腐败菌的敏感性、最小抑菌浓度和最小杀菌浓度.试验结果表明,随着阿魏酸的质量浓度升高,其铁离子还原能力逐渐增大;随着摩尔浓度升高,其对DPPH自由基、羟基自由基和ABTS自由基清除能力逐渐增大.同时,阿魏酸对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌有抑制效果,随着阿魏酸浓度的提升,其相对应的抑制作用逐渐增强,最低抑菌浓度分别为12.5 mg/mL、6.25 mg/mL、6.25 mg/mL,最低杀菌浓度分别为200 mg/mL、>400 mg/mL、200 mg/mL.     

牛油果中植物甾醇的鉴定及抗氧化、抑菌活性

以牛油果为原料,采用皂化法提取牛油果中植物甾醇,并对牛油果中植物甾醇种类、含量、抗氧化活性及抑菌活性进行分析研究。采用气相色谱-串联质谱联用法鉴定出牛油果中4?种主要植物甾醇：β-谷甾醇、菜油甾醇、胆固醇、豆甾醇,其含量分别为59.47、30.36、15.34、2.72?mg/100?g。以VE为对照,测定并分析了牛油果中植物甾醇对自由基（1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、羟自由基（·OH）及超氧阴离子自由基（O2－·））的清除能力。植物甾醇对DPPH自由基、·OH、O2－·具有明显的清除效果,半数抑制浓度分别为6.82、35.92、17.08?μg/mL。采用抑菌圈法分析了甾醇粗提物对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌和沙门氏菌的抑菌活性。抑制作用强度依次为枯草芽孢杆菌＞金黄色葡萄球菌＞沙门氏菌＞大肠杆菌,表明牛油果植物甾醇具有较好的抑菌活性。     

黄精多酚的闪式提取及抗氧化活性研究

采用闪式提取的方法提取黄精中的多酚类化合物,研究其最佳的提取工艺,同时探讨黄精粗多酚的抗氧化活性。结果显示,闪式提取法提取黄精多酚的最佳工艺为:以50%乙醇为提取剂、料液比为1:20、电压为150 V、提取时间为35 s、提取2次,黄精多酚的提取率较高,为(0.4788±0.0023)%。抗氧化实验表明,黄精多酚粗提物具有较好的总还原能力以及清除DPPH、ABTS自由基的能力,且呈现出良好的量效关系,其总还原能力、清除DPPH和ABTS自由基能力的IC_(50)值分别为27.48、5.21、4.89μg/m L,且均较Vc小。结果提示黄精多酚粗提物具有较好的抗氧化能力。     

The effect of in vitro gastrointestinal simulation on bioactivities of kefir

Kefir is a fermented milk beverage and known to have positive effects on gut microbial diversity and human health. In this study, digested and undigested kefir samples were compared for changes in their antihypertensive, antidiabetic, antioxidant and antimicrobial activities. Results showed that the amount of total phenolic substances, 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) activity, and the angiotensin-converting enzyme inhibitor (ACE-I) activity increased from 43.76 ± 0.005 mg gallic acid equivalents (GAE)/L, 4.20 ± 0.55%, and 9.91 ± 3.90% in undigested kefir to 668.16 ± 3.332 mg GAE/L, 63.06 ± 0.64%, and 98.88 ± 0.42% in digested kefir, respectively. While the dipeptidyl peptidase IV-inhibitory (DPPIV-I) activity of undigested kefir increased by 19.11 ± 7.35% after digestion, the optical density of the ferric-reducing antioxidant power (FRAP) decreased from 1.188 ± 0.05 to 0.278 ± 0.009, and the protein amount decreased from 101.4 mg L⁻¹ to 12.42 mg L⁻¹ in digested kefir. No antimicrobial effect was observed in undigested kefir, whereas, digested kefir samples were active, but only against Escherichia coli. These results show that the gastrointestinal digestion processes of kefir generally increase the number of bioactive molecules, and the digestion process must be taken into account to determine the biological capability of foods.     

驴乳的营养成分及其保健作用的研究进展

驴乳作为营养品广泛使用已有数千年的历史,因其含有多种营养成分和生物活性,是婴幼儿、老年及体弱者补充营养物质的重要来源。该文综述驴乳的营养成分和抗菌、抗炎、抗氧化、抗过敏等保健作用,以期为驴乳产业提供新的方向和理论支持。     

Antioxidant, antimicrobial and anticancer activities of three Parmelia species

BACKGROUND: Lichens are symbiotic organisms consisting of algae and fungi. They are used for human and animal nutrition and in the production of colours, perfumes and alcohol. Lichens have also been used in traditional medicine to treat diseases such as jaundice, pulmonary, stomach and cranial diseases. In this study the acetone extracts of three lichens, Parmelia caperata, Parmelia sulcata and Parmelia saxatilis, were tested for their antioxidant, antimicrobial and anticancer potential. RESULTS: Of the lichens tested, P. saxatilis had the highest free radical‐scavenging activity (55.3% inhibition). Moreover, all tested extracts showed effective reducing power and superoxide anion radical scavenging. Strong relationships between total phenolic and flavonoid contents and antioxidant effects of the tested extracts were observed. The extract of P. sulcata was most active in terms of antimicrobial ability, with minimum inhibitory concentration values ranging from 0.78 to 12.5 mg L^?1. All extracts were found to have strong anticancer activity, with IC₅₀ values ranging from 9.55 to 22.95 µg mL^?1. CONCLUSION: The present study showed that the tested lichen extracts exhibited strong antioxidant, antimicrobial and anticancer effects. This suggests that lichens may be used as possible natural antioxidant, antimicrobial and anticancer agents. Copyright © 2012 Society of Chemical Industry     

Antioxidant, antimicrobial, and anticancer activity of 3 Umbilicaria species

Abstract: The aim of this study is to investigate in vitro antioxidant, antimicrobial, and anticancer activity of the acetone extracts of the lichens Umbilicaria crustulosa, U. cylindrica, and U. polyphylla. Antioxidant activity was evaluated by 5 separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds, and determination of total flavonoid content. Of the lichens tested, U. polyphylla had largest free radical scavenging activity (72.79% inhibition at a concentration of 1 mg/mL), which was similar as standard antioxidants in the same concentration. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. Total content of phenol and flavonoid in extracts was determined as pyrocatechol equivalent, and as rutin equivalent, respectively. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. The most active was extract of U. polyphylla with minimum inhibitory concentration values ranging from 1.56 to 12.5 mg/mL. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. All extracts were found to be strong anticancer activity toward both cell lines with IC₅₀ values ranging from 28.45 to 97.82 μg/mL. The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial, and anticancer effects. That suggests that lichens may be used as possible natural antioxidant, antimicrobial, and anticancer agents.     

Antioxidant and antimicrobial activities of propolis from several regions of Korea

Biological activities of different propolis extracts in Korea were examined for the evaluation of quality comparison with that from Brazil (BZ). Total polyphenol and flavonoid contents of propolis extracts from Yeosu (YS) and Cheorwon (CW), whose values were higher than BZ, were also shown to be more aboudant. The extracts of YS and CW also showed strong antioxidant activities, using the linoleic acid peroxidation and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity. However, the extract from BZ had less active antioxidant activity on linoleic acid peroxidation and DPPH free radical-scavenging activity of less than 70% than other extracts. The DPPH free radical-scavenging activity seems to relate with the antioxidant activity of linoleic acid peroxidation. The propolis with antioxidant activity also had DPPH free radical-scavenging activity. The extracts of YS and CW had effective antimicrobial activities on Staphilococcus aureus, Bacillus subtilis, Salmonella typhimurium and Candida albicans. Strong antioxidant, radical-scavenging and antimicrobial activities of YS and CW seemed to relate with high values, total polyphenol, and flavonoid contents.     

Antioxidant,Antibacterial, and Antiproliferative Activities of Free and Bound Phenolics from Peel and Flesh of Fuji Apple

This study was conducted to investigate the antioxidant, antibacterial, and antiproliferative activities of flesh free (FF), flesh bound (FB), peel free (PF), and peel bound (PB) phenolics from Fuji apple. The PB, which had highest total phenolic contents (126.15 ± 2.41 mg/100 g wet weight) and lowest total carbohydrate contents (34.68 ± 2.78 mg/100 g wet weight), showed the strongest 2,2’‐azinobis‐(3‐ethylbenthiazoline‐6‐sulphonate) (ABTS) radical scavenging activity (EC₅₀ = 0.36 ± 0.02 mg/mL), 1,1‐diphenyl‐2‐picryhydrazyl (DPPH) radical scavenging activity (EC₅₀ = 0.26 ± 0.01 mg/mL), and ferric reducing antioxidant power (Ferric reducing antioxidant power; EC₅₀ = 0.19 ± 0.02 mg/mL) compared with those of FF, FB, and PF. The PB also showed the strongest antibacterial activities on Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes and it also showed the highest antiproliferative effects on Caco‐2 human colonic cancer cell (EC₅₀ = 1.44 ± 0.01 mg/mL) and Hela human cervical cell (EC₅₀ = 2.81 ± 0.01 mg/mL). Both free and bound phenolics from Fuji apple showed good antioxidant, antibacterial, and antiproliferative activities in our study, and bound phenolics had significantly higher activities compared with those of free phenolics.     

4种海南诺丽果内生细菌多样性及其关键生物活性研究

诺丽果富含生物活性成分,具有较强抑菌性和抗氧化能力。为探讨海南诺丽果中内生菌多样性的区别及其关键活性与多样性之间的联系,通过高通量测序技术(HTS),从4种诺丽果(长果标号为L、圆果标号为R、连体果标号为C、大溪地诺丽果标号为T)中发现了它们共同的优势菌属为短波单胞菌属(Brevundimonas)、泛菌属(Pantoea)和芽孢杆菌属(Bacillus),并测定内生细菌抑菌性,对具有抑菌活性的内生细菌进行总抗氧化性测定,发现具有抑菌性的诺丽果内生细菌均具有抗氧化性,抗氧化值在3.07～20.78U·mL-1,同时内生细菌的抗氧化性和抑菌活性呈正相关性。挑选4个品种诺丽果中2种关键活性较高的内生菌8株,进行16S rDNA和gyrA分子生物学鉴定,鉴定结果均为芽孢杆菌属(Bacillus),并分别属于枯草芽孢杆菌(Bacillus subtilis)、摩加夫芽孢杆菌(Bacillus mojavensis)和短小芽孢杆菌(Bacillus pumilus)。研究结果从微生物学角度比较了不同品种诺丽果内生细菌群落多样性差异,并探讨了内生细菌功能性之间以及与内生群落之间的关联,证实了植物-微生物相互作用学说。希望研究可为今后研究内生菌和宿主功能的协调性和统一性提供帮助,为具有特定功能的诺丽果内生菌的筛选应用提供理论基础,为内生菌在食品工业中的应用及植物与微生物互作研究提供更多思路。     

姜黄素的抗氧化及抗肿瘤活性研究

本文采用分光光度法测定姜黄素对ABTS和DPPH自由基的清除能力;运用AAPH诱导红细胞氧化性溶血考察姜黄素对AAPH诱导人血红细胞损伤的抑制作用。通过MTT方法考察姜黄素对A375恶性黑色素瘤生长状态的影响,并用流式细胞仪检测细胞凋亡数量;运用Western blot测定姜黄素对JNK和Akt蛋白表达的影响。结果表明,姜黄素对DPPH和ABTS自由基具有较好的清除能力,呈浓度和时间依赖性;同时,姜黄素能有效抑制AAPH诱导红细胞溶血,当姜黄素为40μM时,溶血抑制率达到52.78±1.03%。MTT结果表明,随着姜黄素浓度的升高,A375细胞存活率逐渐下降,当姜黄素为40μM,A375的细胞存活率仅为21.50±1.60%。流式分析发现,随着姜黄素浓度的提高,细胞凋亡峰(Sub G1)的含量逐渐增加。当姜黄素为40μM时,细胞内Sub G1峰的含量达到了63.30%。进一步Western blot分析发现姜黄素诱导A375细胞凋亡与上调JNK磷酸化的水平和下调AKt磷酸化的水平有关。     

红参浓缩液对小鼠的抗氧化、免疫调节及降血糖作用

该研究通过建立衰老小鼠模型和II型糖尿病小鼠模型,对比不同剂量的红参浓缩液对小鼠体内抗氧化、免疫及降血糖活性影响。实验发现：与模型组相比,红参浓缩液给药组显著降低丙二醛含量（MDA）、空腹血糖（FBG）和口服葡萄糖耐量（OGTT）血糖曲线下面积（AUC）并且显著提高羟自由基清除率（•OH）、总超氧化物歧化酶（T-SOD）、谷胱甘肽过氧化氢酶（GSH-Px）和过氧化氢酶（CAT）活力和免疫球蛋白G（Ig G）、免疫球蛋白M（Ig M）、白细胞介素4（IL-4）和γ干扰素（IFN-γ）含量（P<0.05）,明显改善脾脏损害。以上结果表明一定浓度的红参浓缩液可以延缓衰老、提高衰老模型小鼠的免疫力,增强II型糖尿病模型小鼠的葡萄糖耐受力,具有降血糖的效果。     

Antiproliferative and antibacterial activity of extracts of Ganoderma strains grown in vitro

Food Science and Biotechnology - In this bioprospecting study the biological activities of extracts of the in vitro culture of Ganoderma Mexican strains were evaluated. The extracts were tested by...