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1.
酸模叶蓼抗氧化活性   总被引:9,自引:8,他引:1  
目的:评价酸模叶蓼体外总抗氧化活性。方法:采用清除二苯代苦味酰基(DPPH)自由基、清除[2,2-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐](ABTS)自由基和铁离子还原/抗氧化能力(FRAP)测定法。结果:将测定结果与6-羟基-2,5,7,8-四甲基苯并二氢吡喃-2-羧酸(trolox)及阳性对照没食子酸丙酯(PG)、丁基羟基茴香醚(BHA)和2,6-二叔丁基对甲酚(BHT)进行比较,发现乙酸乙酯和甲醇提取物清除DPPH自由基、清除ABTS自由基及还原Fe3+的能力均比BHT强,比PG和BHA弱。结论:酸模叶蓼具有良好的体外抗氧化活性。在3种提取物中,乙酸乙酯提取物抗氧化能力最强,甲醇提取物次之,石油醚提取物几乎没有抗氧化活性。  相似文献   

2.
多叶棘豆清除自由基活性研究   总被引:1,自引:1,他引:0  
目的:研究多叶棘豆的清除自由基活性。方法:分别以常用抗氧化剂L-抗坏血酸和生育酚为对照,采用清除DPPH和ABTS自由基的方法对多叶棘豆乙醇提取物不同极性部位,以及AB-8大孔吸附树脂柱不同乙醇浓度洗脱部位进行清除自由基能力的评价。结果:多叶棘豆提取物AB-8大孔吸附树脂柱的50%乙醇洗脱部位对DPPH自由基和ABTS自由基均有较强的清除能力,其清除DPPH自由基能力强于同浓度的L-抗坏血酸。结论:AB-8大孔吸附树脂柱层析技术对多叶棘豆的清除自由基活性物质有分离富集作用,以50%乙醇洗脱部位活性最为突出。  相似文献   

3.
目的研究九牛造的抗氧化活性。方法以抗坏血酸为阳性对照,通过DPPH法、邻苯三酚自氧化法、邻二氮菲-Fe2+法测定九牛造不同极性萃取物清除DPPH·、·O2–和·OH的能力。结果丙酮提取物对三种自由基均有较好的清除作用,其能力优于或相当于维生素C,且其抗氧化物质主要集中于95%乙醇洗脱部分。结论九牛造具有一定的抗氧化活性,尤其是丙酮部分有进一步分离开发的价值。  相似文献   

4.
Chemiluminescence (CL) was observed during the oxidation of luminol (2 mg/L). mediated by 0.06% hydrogen peroxide (H(2)O(2)) and cytochrome c (10 mg/L). CL intensity was decreased by the presence of radical scavengers and the reduction was linearly proportional to the concentration and ability of scavengers; butylated hydroxytoluene (BHT), caffeic acid and gallic acid. The order of effectiveness as radical scavengers was gallic acid > caffeic acid > BHT, which shows that the number of hydroxyl groups (OH) in the B-ring of flavonoids plays a key role in a good radical scavenging activity. Of eight catechins obtained from green tea extracts, (-)-catechin was the least effective and (-)-epigallocatechin gallate (EGCg) showed the strongest activity. This result indicates that the stereoscopic structure between the C-3 group and the B ring of flavonoids as well as substituents at the C-3 position make a contribution to radical scavenging activity. Of the tested Chinese herbal ingredients, five species of ingredients represented more than 90% of the radical scavenging activity.  相似文献   

5.
The antioxidant properties of aqueous and ethanolic extracts of the Uncaria tomentosa bark were evaluated. The analysis included trolox equivalent antioxidant capacity (TEAC), peroxyl radical-trapping capacity (PRTC), superoxide radical scavenging activity (SOD) and quantitation of total tannins (TT) and total phenolic compounds (TPC). The obtained results indicate high antioxidant capacity of the studied materials in comparison to the other extracts of fruits, vegetables, cereals and medicinal plants. Higher antioxidant activity and total phenolic compounds of the alcoholic preparations -- TEAC=0.57 mmol of Trolox/g, PRTC=0.52 mmol of Trolox/g and SOD=0.39 U/mg than of the aqueous preparation -- TEAC=0.34 mmol of Trolox/g, PRTC=0.19 mmol of Trolox/g and SOD=0.10 U/mg were observed. These results might suggest higher medical suitability of alcoholic extracts. However, the highly elevated level of tannins in alcoholic extracts may cause undesirable gastric effects.  相似文献   

6.
The present study aims to determine the in vitro antiproliferative and antioxidant activities of various extracts from the leaves of Melastoma malabathricum using various established in vitro assays. The aqueous extract inhibited the proliferation of Caov-3 and HL-60 cell lines, while the chloroform extract exhibited antiproliferative activity against the Caov-3, HL-60, and CEM-SS cell lines. The methanol extract demonstrated antiproliferative activity against more cell lines, including the MCF-7, HeLa, Caov-3, HL-60, CEM-SS, and MDA-MB-231 cancer cell lines. Interestingly, all extracts did not inhibit the proliferation of 3T3 cells, thus indicating their noncytotoxic properties. Unlike the chloroform extracts, the aqueous and methanol extracts of M malabathricum (20, 100, and 500 μg/ml) produced high antioxidant activity for the superoxide scavenging assay with only the 500 μg/ml aqueous and methanol extracts exhibited high activity for the 2,2-diphenyl -1-picrylhydrazyl radical scavenging assay. The total phenolic content recorded for the aqueous, methanol, and chloroform extracts were 3344.2 ± 19.1, 3055.1 ± 8.7, and 92.5 ± 7.3 mg/100 g of gallic acid, respectively. The M malabathricum leaves possessed potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds.  相似文献   

7.
Lythrum salicaria (purple loosestrife) known as "Tibbi hevhulma" in Turkish is used for its several beneficial health effects against as diarrhea, chronic intestinal catarrh, hemorrhoid and eczema in the form of a decoction or a fluid extract and to treat varicose veins, bleeding of the gums, hemorrhoid and eczema, externally. Dried herbal parts of Lythrum salicaria L. (Lythraceae) were sequentially extracted with different solvents such as petroleum ether, ethyl acetate, methanol and 50% aqueous methanol. Water extract of Lythrum salicaria was also prepared under reflux. Antioxidant, anti-inflammatory and anti-nociceptive activities of all the extracts were investigated using in vitro and in vivo methods, respectively. Free radical scavenging activity (1,1-diphenyl-2-picrylhydrazyl, DPPH* assay), iron(III) reductive activity, capacity of the inhibition of linoleic acid peroxidation and MDA formation, anti-nociceptive activity (p-benzoquinone-induced abdominal constriction test) and anti-inflammatory activity (carrageenan-induced hind paw edema model) were used for all the extracts. In addition, the content of total phenolics, flavonoids and flavonols in all the extracts were determined with spectrophotometric methods. Results were compared with reference antioxidants via ascorbic acid, butylated hydroxytoluene, and gallic acid. Qualitative and quantitative compositions of all the extracts were analysed using a HPLC-PDA system. Polar fractions were found to be rich in flavonoids such as isovitexin and isoorientin.  相似文献   

8.
参麦注射液抗氧化活性体外实验研究   总被引:1,自引:0,他引:1       下载免费PDF全文
[目的]系统研究参麦注射液体外抗氧化性能。[方法]采用铁还原抗氧化能力(FRAP)法、1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除法、一氧化氮(NO)自由基清除法、过氧化氢(H_2O_2)清除法、亚铁(Fe~(2+))离子螯合法分别测试不同稀释倍率参麦注射液的总抗氧化能力、DPPH·清除活性、NO·清除活性、H_2O_2清除活性和Fe~(2+)离子螯合活性,并将结果与0.1mg/mL 2,6-二叔丁基对甲酚(BHT)、10 mmol/L水溶性维生素E(Trolox)和10%柠檬酸的结果进行比较。[结果]参麦注射液具有一定的体外抗氧化能力,总抗氧化能力和对自由基清除活性均呈浓度正依赖性;10倍稀释参麦注射液总抗氧化能力显著低于BHT和Trolox(P0.01),但高于柠檬酸(P0.01);参麦注射液对不同自由基清除能力存在差异,其强弱顺序为:NO·[(54.4±6.6)%]Fe~(2+)离子螯[(42.6±3.2)%]DPPH·[(36.2±2.8)%] H_2O_2[(23.5±1.2)%]。[结论]参麦注射液体外抗氧化活性研究将为其抗氧化药理学机制提供了实验依据。  相似文献   

9.
The peroxyl radical scavenging activity of a dry methanol extract of Misodendrum punctulatum was determined by means of luminol-enhanced chemiluminescence assay, allowing to calculate the total reactive antioxidant potential (TRAP) index equal to 239 +/- 26 microm, expressed in Trolox equivalents. The flavan-3-ol catechin (1) and the phenylbutanone derivative myzodendrone (2) were identified through assay-guided fractionation as active metabolites present in the extract, and their structures were elucidated by chemical and spectroscopic analysis. Three other structurally related synthetic phenols, dehydrozingerone (3), zingerone (4) and myzodendrone aglycone (5), were also analysed using this method. Compounds 1 and 2 were highly effective as free radical scavengers (TRAP = 1257 microm and 1018 microm, respectively) when compared with Trolox (TRAP = 144 microm), used as a standard. Compounds 3 and 5 were also active showing TRAP values of 229 microm and 219 microm, respectively, similarly to that observed for the dry extract. On the other hand, 4 was inactive. Catechin (1) also reduced the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates, with IC50 = 26 microg/mL, superior to that obtained for Trolox, IC50 = 73 microg/mL. Compounds 2 and 5 showed IC50 values > 1000 microg/mL, while no activity could be observed for 3, 4, or the extract.  相似文献   

10.
The active-oxygen scavenging activity of 70 traditional herbal medicines used in China and Japan as nourishing tonics were evaluated by electron spin resonance (ESR) technique, in order to evaluate their effectiveness for anti-aging and to search for new active-oxygen scavengers from natural resources. Most of the 70 herbal medicines showed scavenging activity with various intensities. Areca catechu (methanol extract), Dendrobium plicatile (methanol extract), Juglans regia (water extract), Paeonia lactiflora (methanol extract), Psychotria serpens (water and methanol extracts), Rhodiola sacra (water and methanol extracts) and Uncaria rhynchophylla (water extract) especially showed strong scavenging activity against superoxide anion radical (*O2-), while J. regia (water and methanol extracts), Morus alba (water extract) and Schisandra chinensis (water extract) revealed strong scavenging activity against hydroxyl radical (HO*). In addition, the active-oxygen scavenging activities of 19 compounds isolated from R. sacra were also examined, and hydroquinone (1), caffeic acid (3), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), heterodendrin (17) and gallic acid 4-O-beta-D-glucopyranoside (19) were found to show mild or strong inhibitory activity against superoxide anion radical (*O2-), while 4-hydroxybenzoic acid (2), 3, 4-hydroxycinnamic acid (4), 6-8 and 19 inhibited hydroxyl radical (OH*). These active-oxygen scavengers may contribute, to different extents, to their anti-aging action.  相似文献   

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