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91.

Objective

To evaluate the antioxidant potential of methanolic leaf extract of Indigofera cassioides (MEIC) using various in vitro antioxidant assay systems.

Methods

Antioxidant and free radical scavenging activity of MEIC was assayed by using different in vitro models like ABTS, DPPH, nitric oxide, superoxide, hydrogen peroxide and hydroxyl radical. Reductive ability of the extract was tested by the complex formation with potassium ferricyanide. Further total phenol and flavonoid contents of the crude extract were also determined. Rutin and ascorbic acid were used as standards.

Results

MEIC exhibited potent and concentration dependent free radical scavenging activity in all the tested models. Reductive ability was also found to increase with increase in MEIC concentration. Total phenol and flavonoid content determination showed that the extract is rich in phenols and flavonoids.

Conclusions

All the results of the in vitro antioxidant assays reveal potent antioxidant and free radical scavenging activity of the leaves of Indigofera cassioides, equivalent to that of standard ascorbic acid and rutin. This potent antioxidant activity may be attributed to its high phenolic and flavonoid contents.  相似文献   
92.
目的 积极预防和正确处理胎盘滞留,减少产后出血及产褥感染。方法 产后胎盘滞留时间较短的可以行人工剥离胎盘术。如用手剥离过程中发现宫壁与胎盘之间没有分界线或有草根样条索状连接时,可能有胎盘植入,需停止剥离,根据情况决策保守治疗或行子宫切除术。若产后胎盘滞留时间较长,有明显感染,再行清宫术。结果 96例产后胎盘滞留患,均痊愈出院。结论 落实好避孕措施,减少流产次数;提高引产,流产技术操作水平;正确处理第三产程等可有效预防胎盘滞留的发生。对于胎盘滞留,应根据不同情况给予相应的处理,可减少产后出血及产褥感染。  相似文献   
93.
目的探讨复方丹参的体外抗氧化活性。方法采用DPPH自由基、超氧阴离子、羟基自由基、鳌合亚铁离子和还原力、过氧化氢的反应体系,检测了复方丹参的体外抗氧化活性,并与维生素C进行比较。结果复方丹参和维生素C消除DPPH自由基的EC50分别是41.0μg/mL和8.2μg/mL;复方丹参消除超氧阴离子自由基的EC50是1.39 m g/mL;复方丹参和维生素C抑制羟基自由基产生的EC50分别是1.73 m g/mL和0.58 m g/mL;在实验体系中,未检测到复方丹参螯合亚铁离子的能力;复方丹参和维生素C的还原能力的EC50分别是0.42 m g/mL和0.08 m g/mL。在实验最高质量浓度100μg/mL时,复方丹参和维生素C对过氧化氢的清除率分别为36%和94%。结论复方丹参具有较强还原力,能清除DPPH和超氧阴离子自由基的作用,并抑制羟基自由基的产生。复方丹参的多方面抗氧化活性可能是在治疗心血管疾病效果显著的原因之一。  相似文献   
94.
Actinidia arguta is a species disseminated in Europe and classified by the Chinese Herbal Medicine as a medicinal plant. The fruit (kiwiberry) has been extensively exploited for multiple purposes, while leaves where discarded. The objective of this study was to evaluate the optimal Subcritical Water Extraction (SWE) temperature (110 °C - 160 °C) of antioxidants and polyphenols from A. arguta leaves. The optimal temperature of extraction was 123 °C, revealing the highest phenolic and flavonoid contents and good scavenging efficiencies against HOCl (IC50 = 17.06 μg/mL) and O2●- (IC50 = 335.2 μg/mL), without toxicity on intestinal cells. The phenolic profile was characterized by high amounts of phenolic acids (e.g., gallic acids), flavanols (catechin) and flavonols (e.g., quercetin-3-O-galactoside). This work allows to conclude that SWE can be a useful extraction technique for the recovery of polyphenolics from A. arguta leaves.  相似文献   
95.
目的:建立大黄特征化学成分和抗氧化活性相关联的二维指纹图谱,研究大黄抗氧化活性物质。方法:利用高效液相多检测器联用的抗氧化活性成分在线检测体系,对大黄中化学成分进行检测,共鉴定出大黄中化学成分15种;其中8种具有抗氧化活性;然后采用清除效率为指标对各活性成分的抗氧化活性进行评价。结果:结果发现化合物葡萄糖紫丁香酸、腺嘌呤、没食子酸、儿茶素或表儿茶素、双花母草素、2-O-桂皮酰-没食子酰葡萄糖等具有较强的清除ABTS·+的活性,而蒽醌类成分对ABTS·+的清除作用较弱。结论:采用HPLC-ABTS-DAD-Q-TOF/MS对大黄中的抗氧化活性成分进行快速分析鉴定,初步阐明大黄在抗氧化环节起作用的效应物质。  相似文献   
96.
Background and Objectives  Complement inhibition is considered important in the mechanism of action of intravenous immunoglobulin (IVIG) in a number of inflammatory and autoimmune disorders. The capacity of different IVIG preparations to 'scavenge' activated C3 and thereby inhibit complement activation was assessed by a new in vitro assay.
Materials and Methods  Diluted human serum as a complement source, with or without addition of different concentrations of IVIG, was incubated in microtitre plates coated with heat-aggregated human IgG. Complement scavenging was measured by detecting reduced C3 binding and determining fluid phase C3b–IgG complex formation. Complement activation induced by the IVIG preparations was measured as C5a formation.
Results  All IVIG preparations exhibited a dose-dependent inhibition of C3b deposition, correlating strongly with binding of C3b to fluid-phase IgG, but the extent of complement scavenging varied considerably between different IVIG preparations. At an IVIG concentration of 0·9 mg/ml, the inhibition of C3b deposition ranged from 72 ± 16% to 22 ± 4·1%. The reduction of C3b deposition on the complement-activating surface was not due to IVIG-induced complement activation in the fluid phase, as shown by the low C5a formation in the presence of serum.
Conclusion  In vitro analysis allows comparison of the complement-inhibitory properties of IVIG preparations. The extent of complement scavenging varies between the products.  相似文献   
97.

Background

The genus Asphodeline (Liliaceae) is represented in Turkey by 20 taxa, which are traditionally used for medicinal purposes in Anatolia.

Materials and Methods

In this study, we tested the phytochemical content and antioxidant effect of different solvent extracts obtained from different anatomical parts of Asphodeline anatolica. The different extracts of each plant parts were tested for antioxidant activity using different chemical assays. The total antioxidant components were also calculated.

Results

Generally, acetone extracts produced the seed and root exhibited significantly higher antioxidant activity with high antioxidant components. Total phenolic content of extracts were significantly correlated with antioxidant potentials (except for, metal chelating activity).

Conclusion

On the basis of the results obtained, A. anatolica extracts should be regarded as a valuable source of natural antioxidants for food and therapeutic applications.  相似文献   
98.
目的为八角果资源的合理开发和利用提供科学依据。方法分别以乙醇、石油醚、水等作提取溶剂,用超声波与非超声波对比提取八角果总黄酮,考察在不同温度、溶剂浓度、超声波功率、提取时间等不同条件下用超声波乙醇浸提法提取八角果总黄酮,对所提取的黄酮类物质进行验证,并用分光光度法测定含量,用八角果总黄酮对羟自由基清除作用进行试验。结果超声波乙醇浸提法提取八角果总黄酮的最佳工艺条件为:溶剂为60%(V/V)乙醇,温度80℃,超声波功率50 W,提取时间2.0 h。百色、崇左、柳州、河池、天等、玉林、桂林等地所产八角果总黄酮的含量分别为3.359、8.404、6.367、4.350、5.720、5.073、3.845g/L,八角果总黄酮提取液对Fenton体系产生羟自由基有很好的清除作用。结论超声波乙醇浸提法提取八角果总黄酮的效果最佳,桂林八角果总黄酮含量最高,研究表明,桂林八角果具有较高的开发利用价值。  相似文献   
99.
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.  相似文献   
100.
Context: Actinobacteria are a precious source of novel bioactive metabolites with potential pharmaceutical applications.

Objectives: Representatives of 11 genera of rare Actinobacteria were selected for the evaluation of antioxidant activity.

Material and methods: Fermentation broths of the Actinobacteria were extracted and dosage of 10 to 2000?µg/mL were applied for in vitro antioxidant-related bioassays. Cytotoxicity was assessed at the concentration of 2.5–20?µg/mL.

Results: In the DPPH scavenging activity, 15 out of 52 extracts showed 17.0–26.8% activity in quantitative evaluation. Metabolites of five prominent antioxidant producing strains protected the DNA (pUC19) against UV-induced photolyzed H2O2-oxidative degradation. The potent antioxidant extracts inhibited two oxidative enzymes of xanthine oxidase in the range of 17.5–45.2% (three extracts had IC50 less than allopurinol) and lipoxygenase in the range of 36–55% (all five extracts had IC50 values less than daidzein). All these extracts could also protect eythrocytes from iron-induced hemolysis with ED50 values in a range of 0.014–1.25?mg/mL. Growth restoration of the yeast cells lacking the sod1 gene was observed by the antioxidant metabolite of Saccharothrix ecbatanensis UTMC 537 at the concentration of 1?mg/mL.

Conclusions: The presence of nonidentical metabolites might be responsible for antioxidant and enzyme inhibitory activities of S. ecbatanensis, newly described actinobacterium in family Pseudonocardiaceae. The scavenging of the free electrons, protection of DNA and model yeast cells against oxidative stress, in addition to the inhibition of the oxidating enzymes are the main mechanisms of the antioxidant effect of the introduced resource in this study.  相似文献   
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