青砖茶提取物不同极性部位的体外抗氧化作用研究

目的:研究青砖茶提取物不同极性部位的体外抗氧化作用,初步探明其体外抗氧化作用及活性部位,同时将其开发成抗氧化性产品提供科学依据。方法:采用清除DPPH自由基(DPPH·)、清除ABTS自由基(ABTS·~+)及测定总还原能力3个体外指标来评价青砖茶提取物不同极性部位的抗氧化能力。结果:青砖茶提取物不同极性部位中清除DPPH·能力和测定的总还原能力排序一致,为乙酸乙酯层正丁醇层水提取物水层氯仿层;清除ABTS·~+能力为正丁醇层乙酸乙酯层水层水提取物氯仿层。结论:青砖茶具有体外抗氧化作用,其提取物不同极性部位的抗氧化活性以乙酸乙酯层和正丁醇层较强,水提取物和水层较弱,氯仿层很弱。     

亨氏马尾藻醇提取物及其不同溶剂萃取物的抗氧化活性研究

研究了亨氏马尾藻95%乙醇提取物不同溶剂级分的体外抗氧化活性。采用Folin-Ciocalteu法测定亨氏马尾藻醇提取物(总提取物)以及石油醚萃取物、乙酸乙酯萃取物、正丁醇萃取物和水萃取物五个部位的总酚含量,并通过DPPH·、ABTS~+·清除及ORAC三种方法评价五种提取物的抗氧化活性。结果表明,乙酸乙酯萃取物的总酚含量最高,为(12.71±0.02)mg GAE/g(没食子酸当量)。在不同抗氧化测定方法中,亨氏马尾藻醇提取物及其不同溶剂萃取物均表现出不同程度的抗氧化活性。其中,乙酸乙酯萃取物抗氧化活性较强,其DPPH和ABTS半数清除率分别为(0.89±0.01)mg/m L和(0.73±0.03)mg/m L,ORAC值达到(1803.78±81.37)μmol TE/g。     

山豆根提取物抗氧化和抑菌活性的研究

研究山豆根不同溶剂(氯仿、乙酸乙酯、正丁醇、乙醇)提取物的抗氧化活性和抑菌活性,通过测定四种提取物的DPPH自由基、ABTS自由基、羟自由基的清除能力以及还原能力来评估其抗氧化能力;并通过测试各提取物对7种实验菌的最低抑菌浓度(MIC)来评估它们的抑菌活性。结果表明:山豆根四种溶剂提取物均具有一定的抗氧化能力和抑菌活性,其中,对DPPH自由基的清除效果最佳,EC50均小于0.2mg/m L;乙酸乙酯提取物对金黄色葡萄球菌有明显的抑菌作用,其MIC为0.313mg/m L。     

全缘马尾藻褐藻多酚的抗氧化和抗肿瘤细胞增殖作用研究

检测全缘马尾藻褐藻多酚提取物(IPTs)的抗氧化和抗肿瘤细胞增殖作用。通过萃取和超滤获得4种IPTs提取物-IPTa1、IPTa2、IPTe1和IPTe2,总酚含量分别为1.16、0.6、0.25和0.34 mg没食子酸（GA）/g海藻干基,1.5 mg/L时的总抗氧化能力（TCA）分别相当于1.724、1.379、1.833、0.695 mg/L的Fe2+还原能力;MTT结果显示,4.4 μg/mL时,4种IPTs提取物作用sw579细胞24 h、48 h、72 h后,除了IPTa2外,IPTa1、IPTe1和IPTe2均以时间依赖方式显著抑制肿瘤细胞的生长;0.3125~5 μg/mL浓度范围内,IPTa1和IPTe1的抑制率与作用时间和浓度呈正相关,最高抑制率达90%以上。     

藏茜草不同溶剂提取物的抗氧化活性研究

采用DPPH自由基清除法、ABTS自由基清除法、羟自由基清除法、超氧阴离子清除法、还原力测定法和螯合力测定法六种抗氧化模型对藏茜草95%乙醇提取物以及石油醚相,乙酸乙酯相,正丁醇相和水相等4个不同极性部位的抗氧化活性进行评价,同时分析抗氧化活性与总酚和总黄酮含量的关系。研究结果表明,除水提部位外,藏茜草其它4个极性部位提取物均表现出一定的抗氧化活性,其抗氧化活性与多酚和总黄酮含量呈显著相关。其中,乙酸乙酯部位总黄酮和总多酚含量最高,抗氧化活性也最强,其总黄酮和总多酚含量分别为(232.03±1.74)mg芦丁当量/g提取物和(173.53±1.75)mg没食子酸当量/g提取物,其清除DPPH自由基、超氧阴离子、羟自由基和ABTS自由基的EC50分别为0.06±0.01、0.17±0.01、(0.24±0.02)mg/m L和(1.75±0.23)μg/m L,对金属离子螯合力的EC50为(0.11±0.01)mg/m L。藏茜草的乙酸乙酯极性部位具有显著的抗氧化活性,是天然抗氧化活性化合物的良好来源。     

两种开封产黄色菊花的体外抗氧化活性

采用清除DPPH自由基、ABTS自由基和铁离子还原/抗氧化能力(tRAP)方法,评价开封产黄色菊花(春日剑山和麦浪)的体外总抗氧化活性,并将所测结果与水溶性维生素E(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylicacid,Trolox)及阳性对照二丁基羟基甲苯(BHT)进行比较.结果发现,不同菊花的不同溶剂提取物抗氧化活性不同.随着提取溶刺极性的增大,同种菊花不同溶剂提取物总的抗氧化活性逐渐增大.即甲醇提取物)乙酸乙酯提取物)石油醚提取物.所有提取物中,麦浪甲醇提取物的抗氧化活性最好.它清除DPPH自由基的能力(IC_(50)=20.01mg/L)略低于BHT(IC_(50)=18.92mg/L),清除ABTS自由基的能力(IC_(50)=25.93mg/L)约为BHT(IC_(50)值为7.72mg/L)的1/3.     

玻璃海鞘不同极性提取物体外抗氧化活性的研究

通过对DPPH自由基、脂质过氧化及总抗氧化能力的测定,从而探求玻璃海鞘不同极性提取物的抗氧化能力。结果表明,玻璃海鞘不同极性提取物均具有一定的抗氧化能力,但均低于VC的抗氧化能力。用IC50衡量清除自由基的能力,正丁醇萃取物清除DPPH自由基能力最强,为(1218.03±4.79)mg/L,其次是石油醚萃取物,乙酸乙酯萃取物最弱;乙酸乙酯萃取物对脂质过氧化的抑制作用最强,为(2325.17±3.80)mg/L,石油醚萃取物次之,正丁醇萃取物最弱;在一定浓度下,总抗氧化能力从强到弱排列顺序依次为石油醚萃取物>乙酸乙酯萃取物>正丁醇萃取物。     

定心藤醇提物不同极性部分的体外抗氧化活性研究

研究定心藤75%乙醇提取物不同极性部位的体外抗氧化活性,采用5种不同极性溶剂萃取(石油醚、氯仿、乙酸乙酯、正丁醇、水)得到5种萃取物,分别测定黄酮含量,并通过还原能力测定、DPPH自由基清除能力、羟自由基清除能力和超氧阴离子自由基清除能力4种测定方法,对各萃取物抗氧化能力进行研究。结果显示,各提取物对Fe3+均有一定的还原能力,乙酸乙酯萃取物还原效果最为明显;定心藤不同极性部位均具有一定的抗氧化活性,乙酸乙酯萃取物抗氧化能力最强,DPPH·的半数清除浓度IC50为0.28mg/m L,羟自由基半数清除浓度IC50为0.41mg/m L,在0.2mg/m L浓度下,对超氧阴离子自由基的清除率达到42.88%,而其黄酮含量最高,达到609.96mg/g,这也许与它具有较高的抗氧化活性有关。说明乙酸乙酯萃取物具有较好的开发天然抗氧化剂的前景。     

热带莫氏兰根提取物的抗氧化活性及稳定性研究

采用超声提取法对莫氏兰根中抗氧化成分进行提取,考察其对羟基自由基(·OH)和DPPH自由基(DPPH·)的清除能力以及pH、温度、光照对其稳定性的影响.结果表明:莫氏兰根中抗氧化成分最佳提取工艺条件为:无水乙醇,料液比为25 mg:25 mL,温度为50℃,提取时间为60min,功率为48W.在此条件下,提取物的抗氧化活性最好,对DPPH·的清除率可达到92.00％.提取物对DPPH·和·OH的半数抑制浓度(IC50)分别为34.62、45.20μg/mL.其还具有较好的耐热性、一定的光稳定性,且在碱性条件下提取物的抗氧化活性较稳定.     

霸王花提取物抗氧化和抗菌活性研究

目的:研究霸王花不同溶剂提取物的体外抗氧化和抗菌活性。方法:用冷浸法得到霸王花乙醇提取物(EE)、丙酮提取物(AE)和乙酸乙酯提取物(EAE),通过测定三种提取物的ABTS自由基清除能力、DPPH自由基清除能力以及还原能力来评估其抗氧化能力;通过纸片扩散法和试管法评估霸王花三种提取物的抗菌活性。结果:霸王花不同溶剂提取物均表现出抗氧化性能,其中乙酸乙酯提取物(EAE)具有最优异的抗氧化能力;霸王花乙酸乙酯提取物(EAE)对伤寒杆菌有明显抑菌效果,其最小抑菌浓度为12.5mg/mL。结论:霸王花提取物具有作为天然抗氧化剂和天然抗菌素研究和开发的潜力。     

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。     

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.     

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.     

Cladonia lichens and their major metabolites as possible natural antioxidant,antimicrobial and anticancer agents

The aim of this study is to investigate in vitro antioxidant, antimicrobial, and anticancer activities of the acetone extracts of the lichens Cladonia furcata, Cladonia pyxidata and Cladonia rangiferina and their atranorin and fumarprotocetraric acid constituents. Antioxidant activity was evaluated by free radical scavenging, superoxide anion radical scavenging, reducing power, and determination of total phenolic and flavonoid compounds. As a result of the study atranorin had largest free radical scavenging activity with IC₅₀ values 131.48 μg/mL. Moreover, the tested samples 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 fumarprotocetraric acid with minimum inhibitory concentration values ranging from 0.031 to 0.125 mg/mL. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. All samples were found to be strong anticancer activity toward both cell lines with IC₅₀ values ranging from 10.97 to 41.23 μg/mL.     

Biological activities of Maillard reaction products (MRPs) in a sugar–amino acid model system

The various biological activities of Maillard reaction products (MRPs) from sugar (fructose and glucose) and 20 amino acid model systems were evaluated. Colour development, in vitro antioxidant, α-glucosidase inhibitory, antihypertensive, and antiproliferative activities of aqueous solutions of MRPs produced by heating at 130 °C for 2 h were measured. The fructose–amino acid mixture showed higher UV-absorbance and browning intensity than the glucose–amino acid mixture. The fructose–amino acid model MRPs showed higher DPPH and ABTS radical scavenging and ACE inhibitory activities than the glucose–amino acid model MRPs. The α-glucosidase inhibitory effect of MRPs derived from fructose– and glucose–tyrosine showed higher α-glucosidase inhibitory activity than that of other MRPs. Sugar–amino acid model MRPs inhibited the growth of HCT116 colon cancer cell in a dose-dependent manner (from 0.5 to 1.5 mg/ml). Glucose MRPs showed slightly higher antiproliferative activity than fructose MRPs. In particular, sugar–tryptophan and –tyrosine MRPs exerted higher biological activities than the other MRPs.     

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.     

浏阳豆豉发酵中高产酶活菌株的分离鉴定及酶活性分析

从浏阳豆豉发酵过程中分离产高酶活菌株,通过形态观察结合分子生物学技术进行鉴定,并对其产蛋白酶、脂肪酶及纤维素酶的活性进行分析。结果表明,分离得到3株菌（编号为000、5132、621）均被鉴定为溜曲霉菌（Aspergillus tamarri）。3株菌的蛋白酶、脂肪酶及纤维素酶的活性测定结果表明,菌株621蛋白酶活性最强,为（207.98±3.20）U/mL;菌株5132的纤维素酶活性最强,为（3.40±1.40）U/mL;菌株000的脂肪酶活性最高,为（90.7±0.64）U/mL。     

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.     

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。