新疆紫草不同极性部位的抗氧化活性研究

目的比较新疆紫草不同极性部位提取物的抗氧化活性。方法采用超临界CO2萃取得到超临界提取物后,萃余物依次用95%乙醇和60%的乙醇提取,对得到的乙醇提取物分别采用不同极性的溶剂分步萃取得到紫草不同极性部位的8个提取物,对上述9个提取物的清除羟基自由基、清除DPPH自由基、总抗氧化活性、抑制脂质过氧化能力等进行了评价。结果超临界CO2萃取物的总抗氧化活性在所有试样中居中,在1 mg·mL 1的浓度下,其清除羟基自由基和DPPH自由基的活性接近或略低于对照品芦丁和BHT,而中等极性部分的乙酸乙酯提取物的抗氧化活性最强,高于同等浓度的对照品BHA和芦丁,但极性较大的部位试样的抗氧化活性总体上相对较弱。结论紫草提取物的各极性部位均具有不同程度的抗氧化能力。     

香樟叶不同溶剂提取物清除DPPH自由基的研究

目的研究香樟叶不同溶剂提取物清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基的作用,筛选出香樟叶清除自由基活性的有效部位。方法采用系统溶剂法将香樟叶的乙醇提取物分成石油醚、三氯甲烷、乙酸乙酯、正丁醇和水5种溶剂提取物,采用DPPH自由基体系法测定其抗氧化活性。结果香樟叶的石油醚、三氯甲烷、乙酸乙酯、正丁醇和水溶剂提取物对DPPH的IC50分别为6.003 8、1.329 8、0.398 7、0.346 7、5.087 0mg·mL-1。结论香樟叶不同溶剂提取物均有抗氧化活性,其正丁醇提取物的抗氧化能力最强。     

别克参提取物抗氧化活性研究

目的：研究别克参提取物的体外抗氧化活性。方法：采用清除二苯代苦味酰基（DPPH）自由基、2,2’-氨基-（3-乙基-苯并噻唑啉-6-磺酸）二氨盐（ABTS）自由基与超氧阴离子（O2^-）自由基法,对别克参不同提取物的体外抗氧化活性进行评价。结果：别克参不同提取物清除DPPH·自由基、ABTS·自由基的能力强弱顺序为：乙酸乙酯提取物〉石油醚提取物〉正丁醇提取物〉水提取物。别克参不同提取物对O2^-自由基有一定的清除能力,但不明显。结论：别克参不同提取物抗氧化活性差异可能与各部位中所含抗氧化成分的种类和结构有关。     

乌梅抗氧化作用的实验考察

目的:研究乌梅提取物抗氧化作用。方法:通过检测还原力和清除DPPH、ABTS和超氧阴离子自由基的能力,分析和评价乌梅提取物的抗氧化活性。结果:乌梅醇提物对DPPH、ABTS自由基的IC50分别为0.500 mg.mL-1及0.253 mg.mL-1;乌梅水提物对DPPH、ABTS自由基的IC50分别0.510 mg.mL-1及0.500 mg.mL-1;乌梅醇提物还原能力大于乌梅水提物,且乌梅醇提物对超氧阴离子自由基的清除作用显著,其清除作用优于乌梅水提物及对照品BHT。结论:乌梅提取物有不同程度的抗氧化活性,其中以醇提物抗氧化作用最强。     

人参提取物EFLA400对苯并芘诱导的小鼠肺腺瘤的抑制作用

作者进行此项试验的目的是研究彩色猕猴桃Actinidia deliciosa果实是否具有心血管保护作用。 将该植物除去果皮的果实制备水提取物和70％乙醇提取物。1）用DPPH自由基清除法和亚油酸乳胶法检测提取物的抗氧化活性。结果显示，水或乙醇提取物在所有试验浓度均有抗氧化活性，水提取物和乙醇提取物在10mg／mL对DPPH自由基的清除率分别为21．559／6和21．80％；     

维吾尔药牛舌草提取物抗氧化活性研究

目的研究维吾尔药牛舌草提取物的抗自由基作用及体内抗氧化功能。方法采用体外分析法观察牛舌草提取物对DPPH·及超氧自由基的清除作用,并进一步针对牛舌草大孔树脂洗脱部位GZB-3及GZB-AB80的提取物,以小鼠血清SOD、GSH-Px的活性和MDA的含量变化,探讨牛舌草提取物在小鼠体内的抗氧化能力。结果牛舌草各提取物具有体外抗自由基功能,其中牛舌草GZB-3及GZB-AB80提取物有较好的清除DPPH·及超氧自由基的作用;牛舌草提取物可显著增强小鼠血清SOD、GSH-Px活性,降低MDA含量,其中GZB-AB80提取物有较好的体内抗氧化能力。结论体内外抗氧化实验表明,牛舌草提取物具有明显的抗自由基作用及抗氧化功能。     

锦灯笼提取物对DPPH自由基清除作用的探讨

目的:探讨锦灯笼提取物对DPPH自由基的清除作用。方法:电子自旋共振法(ESR)。结果:锦灯笼乙醇和甲醇提取物对DPPH自由基的清除作用随浓度的增加而增大。结论:初步确定了中药锦灯笼具有一定的抗氧化活性。     

毛头牛蒡子醇提物抗氧化活性研究

目的研究毛头牛蒡子提取物的抗氧化活性。方法将毛头牛蒡子乙醇提取物采用溶剂萃取法,分成极性不同的4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自由基和超氧阴离子自由基的能力,以测定其抗氧化活性,并与抗坏血酸进行比较。结果清除DPPH自由基能力大小为:抗坏血酸>醋酸乙酯部分>正丁醇部分>氯仿部分>95%乙醇部分,清除超氧阴离子自由基的能力以醋酸乙酯部分、正丁醇部分为好,其他部分认为尚无清除超氧阴离子自由基的活性。结论毛头牛蒡子醇提物醋酸乙酯部分和正丁醇部分具有一定的抗氧化活性,有进一步研究的价值。     

五倍子中多酚类物质对DPPH自由基清除作用ESR研究

为研究五倍子提取物对活性氧自由基的清除作用,采用电子自旋共振(ESR)和自旋捕集技术直接测定不同浓度的五倍子两种方法提取物对1,1-二苯基苦基苯肼自由基的清除作用。五倍子两种提取物具有良好的清除1,1-二苯基苦基苯肼自由基的作用,在实验条件下,五倍子水提取物清除DPPH自由基的IC50为0.414 7 mg/L,五倍子醇提取物清除DPPH自由基的IC50为0.858 6 mg/L。实验结果显示,五倍子中多酚类物质具有较强的抗氧化活性。     

古钩藤醇提液体外抗氧化和自由基清除能力实验研究

目的:研究古钩藤醇提液体外抗氧化和自由基清除能力。方法:采用还原力测定、DPPH、FRAP三种方法对古钩藤醇提液抗氧化和自由基清除能力进行体外评价。结果:古钩藤醇提液抗氧化活性与提取物的还原力有一定联系,对DPPH自由基有一定的清除活性,此外古钩藤醇提液具有较高的总抗氧化(FRAP值为212.546mgFeSO_4/gm_d。结论:古钩藤醇提液体外具有良好的抗氧化和自由基清除能力。     

HPLC determination of phenolic acids and antioxidant activity in concentrated peat extract--a natural immunomodulator

The aim of this study was to devise a method for identification and quantification of phenolic acids in concentrated peat extract samples. The simple reversed-phase HPLC method for simultaneous determination of several phenolic acids was developed. The method was validated and it was suitable for the analysis of phenolic acids in peat extracts. This method allowed identifying eight phenolic acids in peat extracts. Phenolic profiles of two samples of peat extract obtained from different medicinal peats were similar, although variations in amounts of individual phenolic acids were observed. Also, slight variations in total phenolic content were detected. The antioxidant activity of peat extracts was evaluated with spectrophotometric ABTS assay. Differences in antioxidant activity were observed for two samples of peat extract produced from different peat varieties. This differences probably reflected phenolic composition of peat extracts.     

Antifungal and antioxidant activities of organic and aqueous extracts of Annona squamosa Linn. leaves

An increasing demand for natural additives has shifted the attention from synthetic to natural antioxidants and antifungal agents. This study was carried out to evaluate the antifungal and antioxidant activities of methanol, chloroform, and aqueous extracts of Annona squamosa Linn. leaves. The antifungal activities of all extracts of A. squamosa leaves against five different strains of fungi (Alternaria alternata, Candida albicans, Fusarium solani, Microsporum canis, and Aspergillus niger) were evaluated by the agar well diffusion method and the minimum inhibitory concentration of each extract was assessed by antifungal susceptibility using the broth microdilution method. The antioxidant potential of each extract was determined by free radicals (1,1-diphenyl-2-picrylhydrazyl, nitric oxide, and hydrogen peroxide) scavenging activity and reducing power property of A. squamosa leaves. Both organic and aqueous extracts were found to express dose-dependent inhibition against all tested fungi strains in both agar well diffusion and broth dilution methods. The free radical scavenging activity and reducing power property of all extracts were found to be concentration dependent, with the methanol extract exhibiting higher antioxidant activity than the chloroform extract, which was more effective than the aqueous extract of A. squamosa leaves. Results of phytochemical analysis of extracts showed the presence of glycosides, saponins, tannins, flavonoids, phenols, etc. The results obtained from in vitro studies of antifungal and antioxidant activities clearly suggest that the methanol, chloroform, and aqueous extracts of A. squamosa leaves possess antifungal and antioxidant activity.     

Chemical constituents of Myristica fragrans Houttuyn seed and their physiological activities

The antioxidative activity of phenylpropanoid compound extracts from nutmeg (Myristica fragragrans Houttuyn) seed was determined. The antioxidant activity was evaluated using the 1,1-diphenyl-2-picrylhydrazyl radical-scavenging method, superoxide disumutase assay, ferric thiocyanate assay, and radical-scavenging effect assay with electron-spin resonance. High antioxidant activity was found in monoterpenoid extracts including terpinene-4-ol (3), alpha-terpineol (4), and 4-allyl-2,6-dimethoxyphenol (12). Compound, 12 expressed particularly high antioxidant activity.     

Antioxidant and Prooxidant Activities in Aqueous Extracts of Argentine Plants

The antioxidant and prooxidant activities of lyophilized aqueous extracts of 19 Argentine plants were studied using the hydroperoxide-initiated chemiluminescence assay in liver homogenates. Six extracts were found to have an effective antioxidant activity in the range 10–1000 µg dry weight/ml and were further evaluated using the thiobarbituric acid assay (TBARS). Acanthospermum australe, Baccharis coridifolia and B. crispa showed the higher antioxidant activity with both assay systems. Eleven extracts showed antioxidant activity when added in higher amounts and prooxidant activity at lower amounts. Two extracts, from Baccharis grisebachii and Terminalia triflora exhibited prooxidant activity in the 10–1000 µg range.     

Antioxidant and Anticholinesterase Activities in Various Parts of Sonneratia caseolaris (L.)

Cork tree, (Sonneratia caseolaris L.), family Sonneratiaceae, is a typical plant in mangroves. It is widespread in tropical and subtropical tideland throughout the World. It is reported to possess many medicinal properties. For searching new pharmacological activities of Cork tree, the total phenolic contents, antioxidant activities and the electric eel acetylcholinesterase inhibitions and the kinetics of extracts of various plant parts were determined. The graphs of trolox equivalent antioxidant capacity and ferric reducing antioxidant power of all extracts showed good linearity with P-value of slopes less than 0.05. The methanol extract of calyxs by maceration method and methanol extract of stamen by soxhlet method presented moderate trolox equivalent antioxidant capacity values. For ferric reducing antioxidant power assay, all extracts gave fair to low antioxidant activities. The tacrine, stamen extract and seed extract by maceration using methanol showed noncompetitive inhibition on acetylcholinesterase activity. While, luteolin, luteolin glycoside and calyx extract and seed extract by boiling using water presented partial noncompetitive inhibition on acetylcholinesterase activity.     

菟丝子提取物清除自由基作用的研究

目的 研究菟丝子提取物的体外抗氧化活性.方法 采用热水提取、酶-Sevage法除蛋白、不同比例乙醇分级沉淀等方法获得菟丝子多糖提取物;经95％乙醇回流提取,2乙酸乙酯、正丁醇萃取,得到乙酸乙酯和正丁醇提取物.利用1,1-二苯基-2-苦苯肼自由基(DPPH·)和超氧阴离子自由基(O2-·)分别测定了各组分的抗氧化活性.结果 菟丝子提取物均具有一定的抗氧化活性,且呈显著的量效关系.菟丝子乙酸乙酯、正丁醇提取物清除自由基的能力大于氧化型谷胱甘肽,小于还原型谷胱甘肽;菟丝子多糖清除自由基的能力均小于氧化型谷胱甘肽,其中90％醇沉多糖清除自由基的能力较强.结论 菟丝子乙酸乙酯、正丁醇提取物以及90％醇沉多糖是天然抗氧化剂的良好来源,可以进一步分离纯化.     

In vitro antioxidant activity and total phenolic content of the inflorescences, leaves and fruits of Sorbus torminalis (L.) Crantz

The antioxidant potential of 70% methanolic extracts from the inflorescences, leaves and fruits of Sorbus torminalis (L.) Crantz was evaluated using three in vitro test systems: the DPPH (2,2-diphenyl-1-picryl-hydrazyl) and the ABTS [2,2-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid)] free radical scavenging assays, and the AAPH [2,2'-azobis-(2-amidinopropane) dihydrochloride]-induced [corrected] linoleic acid (LA) peroxidation test. The results were compared with the activity of the extracts obtained from the model antioxidant Sorbus species (Sorbus aucuparia L.), and also with the activity of phenolic standards such as quercetin, Trolox [(+/-)-6-hydroxy-2,2,7,8-tetramethylchroman-2-carboxylic acid], BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene) and TBHQ (tert-butylhydroquinone). The radical scavenging capacities of the S. torminalis extracts towards the DPPH radical were in the range of 62.0-244.1 micromolar Trolox equivalents/g d.w. of plant material. They were significantly (p < 0.05) correlated with the results of the ABTS test (r = 0.8535), and with the chain-breaking activities determined in the LA-peroxidation test (r = 0.9831). In comparison with the synthetic standards, the free radical scavenging capacity of the Sorbus extracts was remarkably higher than their chain-breaking activity. Both kinds of antioxidant effects of the extracts were significantly (R2 > 0.8097, p < 0.05) influenced by the total phenolic content (TPC) as determined by the Folin-Ciocalteu method. The plant tissues derived from S. torminalis exhibited lower antioxidant potentials than those of S. aucuparia by a factor of 1.5-3.2, partially due to the lower TPC levels (multiplicity factors of 1.2-1.9). After the original antioxidant capacities of the extracts were recalculated according to the TPC levels, the resulting antioxidant capacities of the phenolic fractions in the S. torminalis extracts were lower than those from S. aucuparia by a factor of 1.1-1.6, suggesting that the distinctive chemistry of the phenolic constituents also influences the antioxidant power of the two species.     

木芙蓉叶抗氧化活性成分谱效关系研究

目的 比较木芙蓉叶不同极性部位的抗氧化活性，测定乙酸乙酯部位抗氧化活性并建立HPLC指纹图谱，研究谱效关系。方法 以DPPH法和ABTS法评价抗氧化活性，筛选木芙蓉叶抗氧化活性最佳部位，测定13批不同产地木芙蓉叶最佳部位的抗氧化活性，并建立HPLC指纹图谱，进行相似度分析、聚类热图分析以及主成分分析(principal component analysis，PCA)，并通过偏最小二乘回归法(partial least squares regression，PLSR)分析其谱效关系。结果 木芙蓉叶不同极性部位抗氧化活性强弱依次为乙酸乙酯部位>正丁醇部位>水部位>石油醚部位。13批木芙蓉叶乙酸乙酯部位有17个共有峰，共指认出5个成分，峰4为秦皮素，峰6为芦丁，峰8为异槲皮苷，峰10为山奈酚-3-O-芸香糖苷和峰15为银椴苷，13批样品的相似度在0.912~0.995。聚类热图分析和PCA将13批木芙蓉叶样品聚为两类；PLSR分析表明，峰3、峰4(秦皮素)、峰6(芦丁)、峰10(山奈酚-3-O-芸香糖苷)和峰12回归系数与抗氧化活性呈正相关，且贡献度较大(VIP>1)，为抗氧化活性的主要有效成分。结论 木芙蓉叶乙酸乙酯部位具有较好的抗氧化活性，木芙蓉叶抗氧化活性为多个成分协同作用的结果，揭示了木芙蓉叶抗氧化活性的药效物质基础。     

龟板体外抗氧化活性的研究

目的研究龟板的体外抗氧化活性,为抗衰老药物的筛选提供参考。方法将龟板分别用石油醚、乙酸乙酯、95%乙醇等极性依次递增的溶剂进行提取得不同提取部位溶出物,用DPPH法进行体外抗氧化活性检测,并与抗坏血酸进行比较。结果龟板95%乙醇提取部位溶出物与石油醚、乙酸乙酯部位提取物相比抗氧化活性均存在显著性差异(P<0.01),且以95%乙醇提取部位溶出物体外抗氧化活性最强,其EC50与抗坏血酸比较相差2.38个数量级。结论龟板95%乙醇提取部位溶出物具有很强的体外抗氧化活性,可作进一步研究。