金线莲乙醇提取物及不同极性部分的体外抗氧化活性作用

目的研究金线莲乙醇提取物及其不同极性部位的体外抗氧化活性作用。方法用80%乙醇制备金线莲乙醇总提取物(CE),以石油醚、乙酸乙酯、正丁醇依次萃取CE得到石油醚部位(PEF)、乙酸乙酯部位(EAF)、正丁醇部位(BF)、水部位(AF),用DPPH自由基清除法、ABTS自由基清除法、羟基自由基清除法测定。结果金线莲乙醇提取物及其不同极性部位对DPPH自由基、ABTS自由基、羟基自由基有不同程度的清除作用,其中乙酸乙酯部位的清除能力最强。结论金线莲乙醇提取物及其不同极性部位具有一定的抗氧化和清除自由基的作用。     

女贞子醇提物不同极性部位的体外抗氧化活性研究

目的:研究女贞子乙醇提取物不同极性部位的体外抗氧化活性,旨在为女贞子抗氧化相关有效成分的分离提供依据。方法:在体外化学模拟的条件下,采用1,1-二苯基-2-苦肼基(DPPH)自由基法、邻苯三酚法测定其对DPPH自由基和对超氧阴离子自由基的清除能力。结果:女贞子醇提物的石油醚、乙酸乙酯、正丁醇3个萃取部位抗氧化结果显示,相同浓度下女贞子乙酸乙酯部位抗氧化效果最强,其次是正丁醇部位、石油醚部位。结论:测定了女贞子醇提物不同溶剂提取物的抗氧化活性,初步确定女贞子中抗氧化相关活性成分主要存在于女贞子醇提物的乙酸乙酯部位。     

新疆鼠尾草不同部位不同极性提取物抗氧化活性

目的:研究新疆鼠尾草地上部分和根部不同极性提取物体外抗氧化活性。方法:新疆鼠尾草地上部分和根部药材的95%乙醇提取物依次用石油醚、乙酸乙酯、正丁醇萃取得相应的提取物和水层部分,将各提取物分别配制成适当浓度的溶液,以Vc为阳性对照,采用1,1-二苯基-2-苦基肼(DPPH)自由基法、超氧阴离子自由基(O-·2)法和铁离子还原法分别测定各提取物的自由基清除能力和铁离子还原能力。结果:新疆鼠尾草地上部分和根部不同极性提取物清除自由基的能力均强于阳性对照Vc,地上部分乙醇层清除自由基的能力(DPPH·法IC500.039 g·L~(-1),O-·2法IC500.130 g·L~(-1))强于根部乙醇层(DPPH·法IC500.160 g·L~(-1),O-·2法IC500.160 g·L~(-1))。对铁离子还原能力的强弱顺序为根部不同极性提取物Vc地上部分不同极性提取物。结论:新疆鼠尾草地上部分和根部不同极性提取物均具有较强抗氧化作用,地上部分可替代根部使用,为合理开发新疆鼠尾草资源提供科学依据。     

DPPH法测定桑椹不同极性部位的抗氧化活性

目的 :研究桑椹不同极性部位的抗氧化活性。方法 :采用1,1-二苯-2-苦基肼(DPPH)法测定桑椹醇提液的石油醚(EVP)、乙酸乙酯(EVE)、正丁醇(EVB)和水(EVW)不同极性部位以及EVE部位经二氯甲烷-甲醇梯度洗脱后不同流份的抗氧化活性。结果:EVB和EVW极性部位清除DPPH自由基的能力弱,EVP和EVE极性部位清除DPPH自由基活性强,其EC50值分别为0.0738、0.1393 mg/m L;EVE经梯度洗脱后的弱极性流份EC50均较小。结论:桑椹中等极性部位的抗氧化能力强,为进一步研究其抗氧化活性成分提供了科学依据。     

太白乌头提取物抗氧化活性研究

目的研究太白乌头提取物的抗氧化活性。方法将太白乌头乙醇提取物采用溶剂萃取法，分成极性不同的五个部分，并采用DPPH法和邻苯三酚自氧化法测定各部分的清除DPPH·（二苯代苦味肼自由基）和·O2^-（超氧阴离子自由基）的能力，以测定其抗氧化活性，并和抗坏血酸进行比较。结果清除DPPH·能力大小为：抗坏血酸〉乙酸乙酯部分〉正丁醇部分〉石油醚部分〉水部分一氯仿部分，清除·O2^-的能力以石油醚部分、乙酸乙酯部分为好，其他部分认为无清除·O2^-的活性。结论太白乌头醇提物乙酸乙酯部分、正丁醇部分和石油醚有较好的抗氧化活性，有进一步分离纯化的价值。     

新疆紫草不同极性萃取部位体外抗氧化活性研究

目的:研究新疆紫草不同极性萃取部位体外抗氧化活性。方法:采用1,1-二苯基-2-三硝基苯肼(DPPH·)自由基清除法、超氧阴离子(O2-·)自由基清除法、羟基(·OH)自由基清除法,测定新疆紫草不同极性萃取物的体外抗氧化活性,并与阳性对照进行比较与评价。结果:不同极性萃取部位对DPPH·、羟基(·OH)自由基及超氧阴离子(O2-·)自由基均有消除能力并呈明显的量效关系,其中乙酸乙酯层、水层、正丁醇层具有较好的抗氧化活性。乙酸乙酯层浓度为1.2 mg/m L以上时,对DPPH·的清除能力超过对照品维生素C。结论:新疆紫草提取物不同极性萃取部位均具有一定的抗氧化活性。其中极性溶剂层抗氧化能力显著。本研究为筛选新疆紫草抗氧化作用部位提供了理论依据。     

藏紫菀不同溶剂提取物的体外抗氧化活性

目的研究藏紫菀不同溶剂提取物的体外抗氧化活性。方法采用1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除法、2,2′-联氮基双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)自由基清除法、超氧阴离子自由基清除法、NO自由基清除法、羟自由基清除法及铁还原/抗氧化能力(FRAP)法,对藏紫菀70%乙醇粗提物、正己烷部位、乙酸乙酯部位、正丁醇部位、水提部位等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多酚和总黄酮含量之间的关系。结果与粗提物相比,乙酸乙酯、正丁醇部位表现出更强的抗氧化活性,且抗氧化活性与总黄酮和总多酚的含量密切相关,乙酸乙酯、正丁醇部位中总多酚含量分别高达(311.09±7.92)、(320.21±10.69)mg没食子酸/g提取物,总黄酮含量最高可达(667.78±19.18)、(623.97±14.01)mg芦丁/g提取物。乙酸乙酯部位对DPPH、ABTS⁺·、·OH、O₂^-·均具有最高的自由基清除活性,而正丁醇部位的NO清除活性和FRAP值均高于其他部位。结论藏紫菀乙酸乙酯、正丁醇部位具有较强自由基清除能力,是活性优异的天然抗氧化剂,可将其用于天然抗氧化活性单体成分的提取和分离。     

雪灵芝醇提物不同极性萃取部分的体外抗氧化活性

目的:通过体外抗氧化和还原活性评价实验,研究藏药雪灵芝乙醇提取物不同极性溶剂萃取部分的抗氧化作用。方法:用体积分数95%的乙醇回流提取雪灵芝粉末,浓缩的乙醇浸膏依次用石油醚、二氯甲烷、乙酸乙酯、正丁醇进行萃取,各部分分别配制成适当浓度的溶液,采用1,1-二苯基-2-苦基肼(DPPH)自由基法,2,2-连氮-双-(3-乙基苯并噻唑啉磺酸-6)二铵盐(ABTS)自由基法和铁离子还原/抗氧化能力(FRAP)法分别测定各部分的自由基清除能力和铁离子还原力。结果:雪灵芝醇提物的4个萃取部分均具有一定的体外抗氧化作用,其中乙酸乙酯与正丁醇部分清除DPPH·,ABTS+·及还原Fe3+的能力均比二氯甲烷与石油醚部分强。结论:雪灵芝提取物清除能力与提取物样品浓度在一定范围内具有良好的量效关系,其中极性较大的乙酸乙酯部分和正丁醇部分的抗氧化活性及还原能力相对较强。     

三白草体外抗氧化活性

目的:研究三白草体外抗氧化活性.方法:采用清除二苯代苦味酰基(DPPH)自由基和[2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐](ABTS)自由基测定法,对三白草提取物抗氧化活性进行评价.结果:正丁醇提取物清除DPPH自由基(IC50=16.94)的能力比BHT清除能力(IC50=18.71 mg·L-1)强,弱于阳性对照PG和BHA清除DPPH自由基的能力(IC50分别为0.89,3.2mg· L-1);清除ABTS自由基的能力(IC50=12.90 mg·L-1)弱于阳性对照PG和BHA清除ABTS自由基的能力(IC50分别为0.81,1.95 mg·L-1),比阳性对照BHT( IC50为7.72mg· L-1)清除ABTS自由基的能力略弱;石油醚提取物和乙酸乙酯提取物清除DPPH和ABTS自由基的能力均比阳性对照PG,BHT,BHA清除DPPH和ABTS自由基的能力弱.结论:三白草正丁醇提取物有抗氧化活性.     

民族药滇白珠的体外抗氧化活性研究

目的:研究滇白珠(G.leucocarpa var.yunnanensis)地上部分乙醇提取物的不同极性萃取部位和大孔树脂柱层析的不同浓度甲醇洗脱部位的抗氧化活性。方法:采用清除DPPH(2,2-二苯基苦味酰基苯肼基)和ABTS[2,2′-连氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐]自由基的方法对滇白珠乙醇提取物的不同极性萃取部位和大孔树脂柱层析的不同浓度甲醇洗脱部位进行清除自由基能力的综合评价。结果:乙酸乙酯部位的抗氧化能力最强,与阳性对照相近。100%甲醇流出部位的抗氧化能力能力最强,强于阳性对照。结论:滇白珠地上部分具有较好的体外抗氧化活性。     

复方心脑肾康抗氧化作用的实验研究

目的探讨复方心脑肾康的抗氧化作用。方法连续给大鼠灌胃复方心脑肾康7 d后,分别建立局灶性脑、肾缺血再灌注模型,检测脑、肾组织匀浆中丙二醛(MDA)、超氧化物歧化酶(SOD)、一氧化氮(NO)、活性氧(ROS)含量。结果与模型组相比,高、中、低三个剂量心脑肾康用药后均能显著降低缺血后脑、肾组织匀浆中MDA、NO、ROS含量,增加SOD活性(P<0.05)并呈剂量依赖性。其中,高剂量效果最好,优于阳性对照药(P<0.05)。结论复方心脑肾康能提高组织中抗氧化酶的活性、抑制自由基损伤、防止脂质过氧化,具有明显的抗氧化作用。     

Antioxidant properties of Glossogyne tenuifolia

Glossogyne tenuifolia (Labill) Cass. (Compositae) is a special medicinal plant in the Pescadores Islands. Ethanolic, cold and hot water extracts were prepared from the dried herb and their antioxidant properties and components were studied. Ascorbic acid, alpha-tocopherol, butylated hydroxyanisole, citric and ethylenediaminetetraacetic acids were used in assays for comparison. With regard to EC(50) values in antioxidant activity, ethanolic and hot water extracts (0.08 and 0.09 mg/ml) were much more effective than the cold water extract (0.76 mg/ml). At 1.0 mg/ml, reducing capacities were 1.57, 0.31 and 1.04 for ethanolic, cold water and hot water extracts, respectively. Scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl radicals were in descending order: ethanolic > cold water > hot water extracts. At 20 mg/ml, the hot water extract chelated all hydroxyl ions (100%) whereas the scavenging ability of the cold water extract was 68.86%. Chelating abilities on ferrous ions were in descending order: cold water > hot water > ethanolic extracts. Phenols were found to be the major antioxidant components. All EC(50) values were below 20 mg/ml, and some even below 0.1 mg/ml, indicating that all three extracts from G. tenuifolia were rich in antioxidant properties.     

Antioxidant effect of Inonotus obliquus

The mushroom Inonotus obliquus (Fr.) Pilát (Hymenochaetaceae), has been widely used as a folk medicine in Russia, Poland and most of the Baltic countries. The purpose of this study was to elucidate the antioxidant capacities of Inonotus obliquus. Four extracts from the fungus were evaluated for antioxidant activity against the 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide, and peroxyl radicals. The polyphenolic extract had a strong antioxidant activity, and the extract containing triterpenoids and steroids presented a relatively strong antioxidant effect. The polysaccharide extract, however, was inactive. The protective effects of these four extracts were assessed against hydrogen peroxide-induced oxidative stress using a human keratinocyte cell line, HaCaT. Our results show that the polyphenolic extract protected these cells against hydrogen peroxide-induced oxidative stress, while the polysaccharide, triterpenoid and steroid extracts were ineffective. Additionally, the remnant polyphenolic and low molecular weight polysaccharide extracts showed a weakly protective effect at a concentration of 50 microg/ml. Our results indicate that Inonotus obliquus has the capacity to scavenge free radicals at concentrations higher than 5 microg/ml and that the polyphenolic extract can protect cells against oxidative stress.     

Antioxidant activity of Osbeckia aspera

Plants of the Osbeckia family have been shown to possess hepatoprotective properties, which could be due to the presence of antioxidant compounds. The plant extract was shown to inhibit significantly in a dose-dependent manner, the activities of the DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical (EC₅₀ of 27.5 μg/mL), xanthine oxidase (EC₅₀ of 1.16 mg/mL) and demonstrate a scavenging effect on hydroxyl radical mediated damage to deoxyribose (EC₅₀ of 140 μg/mL). The plant extract possessed some prooxidant activity from the effect on bleomycin-induced DNA damage, but this was less than that shown by comparable concentrations of (+)-catechin or silymarin. © 1998 John Wiley & Sons, Ltd.     

Antioxidant activity of Cinnamomum cassia

The antioxidant activities of hot water extracts (HWECC) and ethanol extracts (EECC) from the dry bark of Cinnamomum cassia Presl were evaluated in this study. Results showed that at 1.0 mg/mL, the ethanol extracts of C. cassia (96.30%) exhibited a greater inhibition than the alpha-tocopherol (93.74%) on FeCl(2)-ascorbic acid induced lipid peroxidation of rat liver homogenate in vitro. From 0.05 to 1.0 mg/mL, the EECC demonstrated the highest superoxide anions scavenging activity and the strongest anti-superoxide formation activity (p < 0.05). The same extract also showed an excellent antioxidant activity in enzymatic and nonenzymatic liver tissue oxidative systems. EECC revealed the strongest antioxidant activity followed by alpha-tocopherol and HWECC. Compared to alpha-tocopherol, the IC(50) values of EECC were found to be lower in thiobarbituric acid test (IC(50) = 0.24 mg/mL vs 0.37 mg/mL), in cytochrome c test (IC(50) = 0.16 mg/mL vs 0.27 mg/mL) and in xanthine oxidase inhibition test (IC(50) = 0.09 mg/mL vs 0.19 mg/mL). The present study concludes that EECC could be used as a good source of antioxidant in the dietary supplement.     

三叶人字草抗氧化活性研究

目的 研究三叶人字草不同溶剂提取物的抗氧化活性.方法 用冷浸法得到三叶人字草乙醇、丙酮和醋酸乙酯提取物.测定了3种提取物的总酚含量,并通过测定其对DPPH自由基的清除能力和还原能力来研究其抗氧化能力.结果三叶人字草不同溶剂提取物均表现出很强的抗氧化性能,其中醋酸乙酯提取物具有最优异的抗氧化能力.结论 三叶人字草提取物具有作为天然抗氧化剂和功能性食品进行研究和开发的潜力.     

Antioxidant properties of silybin glycosides

New soluble derivatives of the hepatoprotective flavonolignan silybin (1), namely silybin galactoside (2), glucoside (3), lactoside (4) and maltoside (5) were investigated for their radical scavenging and antilipoperoxidation properties. According to cyclic voltammetry the results show that glycosides are weaker electron donors than silybin, although it was of interest that they were found to be more potent scavengers of the 1,1-diphenyl-2-picrylhydrazyl and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)-derived radicals. The glycosides (2)-(5) were more efficient than silybin in preventing tert-butylhydroperoxide-induced lipoperoxidation of rat liver mitochondrial membranes. Furthermore, glycosides (2)-(5) were significantly more cytoprotective than silybin in tert-butylhydroperoxide-damaged rat erythrocytes and primary hepatocyte cultures. Glycosylation of silybin substantially reduced its toxic effects in primary cultured hepatocytes observed during prolonged incubation. These results suggest that silybin glycosides are suitable soluble derivatives of silybin for experimental studies and may have therapeutic potential.     

Antioxidant activity of Aporosa lindleyana root

Four successive and two crude extracts of Aporosa lindleyana Baill. root were tested for antioxidant activity using standard in vitro and in vivo models. The successive methanol and ethyl acetate and crude 50% methanol extracts showed antioxidant activity with IC50 values 3.51+/-0.27, 6.09+/-1.00 and 7.34+/-0.46 microg/ml, respectively, in DPPH method. In the nitric oxide radical inhibition method, the successive ethyl acetate, petroleum ether and methanol extracts showed antioxidant activity. The successive methanol extract at 100 and 200 mg/kg body weight administered for 5 days prior to CCl4 treatment caused a significant increase in the levels of catalase and SOD and a significant decrease in the level of TBARS in liver, kidney and blood, when compared to CCl4 treated control. These results indicate strong antioxidant nature of Aporosa lindleyana root. The in vitro cytotoxicity studies against normal Vero cell lines indicate non-toxic nature of the root extracts. The study provides a proof for the ethnomedical and reported biological activities.     

Antioxidant properties of Indian medicinal plants

The antioxidant properties of methanol extracts of 12 Indian medicinal plants, traditionally used in disease areas that probably involve free radical mechanisms, were evaluated by two methods, namely the DPPH (1,1-diphenyl-2-picryl hydrazyl) test and the lipid peroxidation assay. In the latter assay, seven of these extracts showed 90% or more activity compared with the standard, vitamin E and hence were studied in detail after the removal of interfering pigments. The selective pigment removal from the extracts led to an increase in free radical scavenging activity and a decrease in inhibition of lipid peroxidation.     

Antioxidant activity of Argentine propolis extracts

Propolis is used in Argentine folk medicine. We have examined its possible protective action against oxidative modification of lipid in unfractionated serum. The kinetics of copper-induced oxidation was continuously monitored by measuring the formation of conjugated dienes, as the increase in the absorbance at 234 nm. According to the kinetics of oxidation, the propolis were classified in three different groups. Group I (CE, CO, BO, MO, BE) inhibited lipid oxidation during the initiation and propagation phases even at low concentrations. Group II (SP, CA, AM) increased the lag-phase for conjugated diene formation. All propolis in groups I and II diminished the maximal rate of diene production and the maximal amount of dienes produced. Group III (PA, RA, FE, VR, TV) had no effect on the lipid oxidation. The extent of lipoprotein oxidation was measured by the thiobarbituric acid reactive substance assay. Generation of malondialdehyde-like substances was inhibited and delayed by the presence of propolis extracts from group I and II. Our results justify the use of propolis (groups I and II) as a source of natural antioxidants.