沙枣黄酮的提取及其抗氧化作用的研究

目的 对沙枣黄酮的抗氧化作用进行研究.方法 以70%乙醇为溶剂,超声辅助法提取沙枣中的黄酮,用比色法测定其含量为0.928%;采用比色法测定沙枣黄酮对·OH、O_2~-·和DPPH·等3种自由基的清除作用.结果 沙枣黄酮对3种自由基都有明显的清除作用,清除能力为DPPH·>O_2~-·>·OH.结论 清除率与浓度存在明显的量效关系,当浓度为0.4 mg·ml~(-1)时,其清除率·OH为76.07%,O_2~-·为79.53%,DPPH·为93.91%.     

葛根黄酮的体外抗氧化活性研究

目的:探讨葛根黄酮的体外抗氧化活性。方法:采用总抗氧化能力、DPPH·自由基、羟基自由基(·OH)、超氧阴离子(O2·-)的反应体系,考察葛根黄酮的体外抗氧化能力。结果:葛根黄酮在一定浓度范围内,其反应抗氧化作用的FRAP值、清除DPPH·、羟基自由基、超氧阴离子的能力及抑制过氧化脂质产物丙二醛的作用均呈量效关系;在浓度为500μg/ml时,DPPH·的最大清除率为48%,EC50为450.51μg/ml;在浓度为2.95mg/ml时,羟基自由基的最大清除率为21.14%;在浓度为600μg/ml时,超氧阴离子的最大清除率为60.07%,超氧阴离子的EC50值为213.8μg/ml,抑制MDA生成的IC50为11.3μg/ml。结论:葛根黄酮具有较强的体外抗氧化活性,其机制可能与RPI抗氧化活性和消除自由基能力有关。     

云厚朴大紫丹参清除DPPH·的作用

目的 采用DPPH·法,测定云厚朴SFE-CO2萃取液、乙醇提取液和大紫丹参水提取液清除DPPH·自由基的活性.方法 通过在样品中加入DPPH·,测定吸光度的改变,计算清除率％和C5o.结果 云厚朴SFE-CO2萃取液C50=4.83 μg/mL,云厚朴乙醇提取液C50 =4.171μg/mL;尚未达到C50时,大紫丹参水提取液的清除曲线就趋于平缓.结论 云厚朴SFE-CO2萃取液、乙醇提取液和大紫丹参水提取液都具有清除DPPH·自由基的活性,大紫丹参水提取液清除DPPH·自由基的作用较弱.     

女贞不同生长部位所含抗氧化活性成分研究

目的:研究女贞子不同生长部位抗氧化有效成分个含量。方法:选取女贞植物的果实、树叶、花、枝条作为研究对象,用乙醇浸提超声辅助提取研究对象中的抗氧化活性物质,用有机自由基DPPH·法比较其抗氧化能力的差异,对女贞植物不同部位所含抗氧化活性成分进行了比较和研究。结果:女贞植物的不同部位提取物都有不同程度的抗氧化活性,女贞嫩枝条提取物对DPPH·清除率最强,达到了90.11%;其次女贞花提取物对DPPH·清除率达到了89.64%;老枝条提取物对DPPH·清除率最低,只有3.92%;树叶的清除率是30.69%;女贞子的清除率为46.68%。结论:本研究为更好地开发和利用天然抗氧化植物女贞提供了理论依据。     

山银花黄酮粗提物抗氧化活性的体外观察

目的提取山银花中黄酮类化合物,并体外观察其抗氧化活性。方法以70%乙醇作为提取溶剂,超声提取山银花中黄酮化合物;用邻苯三酚自氧化法、Fenton反应和DPPH反应测定粗提物对不同自由基的清除能力;用MTT法检测粗提物对H2O2诱导的氧化损伤内皮细胞和心肌细胞的保护作用。结果山银花中黄酮粗提物的提取率为5.65%;粗提取物中含黄酮16.35%。山银花黄酮粗提物质量浓度为250μg/mL时对超氧阴离子自由基(O-2·)、羟自由基(·OH)、DPPH自由基(DPPH·)的清除率分别为42.40%、64.99%和28.90%。内皮细胞和心肌细胞与浓度1.0 mmol/L的H2O2共同孵育12 h后,其存活率分别下降到49.21%和61.32%,山银花黄酮粗提物预处理30 min,细胞存活率分别提高到60.45%和69.98%。结论山银花中黄酮提取物对O-2·、·OH、DPPH·有较强的清除能力,并具有明显的抗H2O2氧化损伤、恢复细胞活性作用。     

人参根中黄酮类化合物提取及其抗氧化性研究

目的 提取人参根总黄酮并研究其体内外抗氧化活性.方法 采用乙醇回流和聚酰胺富集法提取人参根总黄酮;通过DPPH法、Fenton法和大鼠饲喂实验研究人参根总黄酮的抗氧化能力.结果 当人参根总黄酮质量浓度为0.5 mg/mL以上时,对DPPH自由基的清除率超过80％;0.6 mg/mL时,对羟自由基清除率可达70.8％;80～120mg/(kg · d)持续饲喂5周能使大鼠脑SOD活性提高17.97％以上.结论 人参根总黄酮在体外对DPPH自由基和羟自由基具有较强清除作用,体内对SD大鼠脑组织中SOD活性亦有增强作用.     

车前草和桑葚及其配伍对自由基清除效果的比较

目的对车前草和桑葚及其配伍对自由基清除作用进行初步比较。方法用蒸馏水作为溶剂,采用比色法测定车前草提取液、桑葚提取液及其配伍对1,1-二苯基-2-三硝基苯肼(DPPH)自由基、O_2~-·自由基和·OH~-自由基三种的清除作用。结果在同等0.1 mg·ml~(-1)的药液浓度下,单味药桑葚清除DPPH自由基作用最强,清除率为57.96%,配伍药车前草:桑葚比例为2:1的清除O_2~-·自由基效果最好,清除率为46.00%,配伍药车前草∶桑葚比例为1:2的清除·OH~-自由基的效用最强,清除率为23%。结论车前草和桑葚及其配伍对O_2~-·自由基和·OH~-自由基清除有正协同作用,而对清除DPPH自由基无协同作用。     

党参提取物的抗氧化活性的研究

目的研究党参提取物的抗氧化活性旨在为深入探讨其作用机理提供参考。方法通过对陕西凤县、南郑、山西陵川三个不同地域的党参醇提取物的DPPH自由基清除率进行研究,比较不同地区党参醇提取物的抗氧化活性。结果经过比较,以上三个地区的党参醇提取物的DPPH自由基清除率分别为17.56%、9.87%和8.03%,所以产自不同地区的党参,其抗氧化活性存在差异;除此之外,凤县党参提取物清除DPPH自由基的IC50为0.85 mg·ml-1。结论党参随着其浓度的增加,其提取物的活性也相应增加,且不同地区的党参的活性也有所不同。     

儿茶酚香豆素清除自由基能力测定及作用机制探索

目的:测定儿茶酚香豆素清除自由基的能力,并研究其作用机制。方法:测定系列不同浓度的4-取代、8-含氮氢键受体和单甲基化儿茶酚香豆素衍生物对DPPH、ABTS·+自由基的清除率,绘制浓度-清除率曲线,结合文献报道的酚类化合物清除自由基的作用机制,研究儿茶酚类香豆素清除自由基的作用机制。结果:所有被测儿茶酚香豆素化合物都具有良好的抗氧化活性,其对ABTS·+自由基的清除能力强于对DPPH的清除能力。当引入含氮氢键受体,形成分子内氢键后,其对DPPH自由基的清除能力减弱,而对ABTS·+的清除能力没有明显变化。当儿茶酚香豆素被单甲基化后,其清除自由基的活性明显下降。结论:儿茶酚类香豆素清除DPPH自由基的作用机制和酚羟基的氢原子转移有关,而清除ABTS·+的作用方式可能是质子丢失,电子转移。     

杨树芽提取物体外抗氧化活性及抗DNA损伤作用

目的运用三种不用方法测定杨树芽提取物体外抗氧化活性及其对DNA损伤的保护作用。方法通过DPPH法、邻苯三酚自氧化法和CuSO4-Phen-Vc-H2O2化学发光体系测定其体外抗氧化活性,并用CuSO4-Phen-Vc-H2O2-DNA化学发光体系测定PBE对·OH致DNA损伤的保护。结果浓度在0.05~0.8mg/mL时,对DPPH自由基的清除率为38.1%~94%;浓度为0.1mg/mL时,随物质的量的增大,对邻苯三酚产生的·O2-抑制率为37.4%~44.2%;浓度在0.05mg/mL~0.8mg/mL时,对·OH自由基的清除率为40.8%~60%。DNA损伤体系中,各浓度均表现出良好的损伤保护作用,浓度大于0.4mg/mL时,效果更加明显。结论杨树芽提取物有较强的抗氧化活性,对DPPH自由基、·O2-和·OH有较强的清除作用,并对·OH所致的DNA损伤有保护作用。     

Potentiation of antimicrobial activity of ciprofloxacin by Pelargonium graveolens essential oil against selected uropathogens

The recent approach of using herbs and antibiotics in combination constitutes a strategy to overcome the problems of resistance and side effects associated with conventional antibiotics. In the present study, the antimicrobial effect of Pelargonium graveolens L' Hér essential oil in combination with ciprofloxacin was evaluated on uropathogens, namely, Klebsiella pneumoniae KT2, Proteus mirabilis PRT3 and Staphylococcus aureus ST2. Minimum inhibitory concentrations of P. graveolens essential oil and ciprofloxacin were determined by the microbroth dilution method and further, the interaction between these two agents was studied by a checkerboard method. The fractional inhibitory concentration index (FICI) was calculated to be 0.375 for both K. pneumoniae KT2 and P. mirabilis PRT3, while for S. aureus ST2 it was found to be 0.5. The values of FICI for the tested microorganisms were found to be ≤0.5, which indicates synergism between P. graveolens essential oil and ciprofloxacin. The concave shaped curve in the isobolograms also depicted a synergistic effect of P. graveolens essential oil and ciprofloxacin against the tested microorganisms. Hence, the synergistic action of P. graveolens essential oil and ciprofloxacin may be applied for the treatment of UTIs, which have hitherto been treated by using only synthetic drugs.     

The comparative effect of novel Pelargonium essential oils and their corresponding hydrosols as antimicrobial agents in a model food system

Essential oils and their corresponding hydrosols, obtained after distillation of various scented Pelargonium (Geraniaceae) leaves were assessed for their antimicrobial activity in a model food system. Both the essential oils and hydrosols were used at 1000 ppm in broccoli soup, previously inoculated with Enterobacter aerogenes (at 10(5) cfu g(-1)) and Staphylococcus aureus (at 10(4) cfu g(-1)). The results showed a complete inhibition of S. aureus in the broccoli soup by the essential oils of 'Sweet Mimosa', 'Mabel Grey', P. graveolens, 'Atomic Snowflake', 'Royal Oak', 'Attar of Roses' and a lesser effect by 'Chocolate Peppermint' and 'Clorinda'; the hydrosols, however, had a potentiating effect on the bacterial population in the food. Both extracts showed a complete inhibition of S. aureus in the Maximum Recovery Diluent (MRD). Antibacterial activity against E. aerogenes in the broccoli soup was generally very much reduced: only the essential oil of 'Mabel Grey' showed complete inhibition and virtually no reductions in colonies were seen with the other essential oils; the hydrosols again caused an increase in bacterial colonies. All the essential oils, bar Chocolate Peppermint showed complete inhibition of E. aerogenes in MRD, but the hydrosols showed no effect. The results strongly suggest that the residual hydrosols from distillation of these plant essential oils have no potential as antibacterial agents in foods, in contrast to most of the essential oils, which show potential against some micro-organisms, but only in some food systems. The problem of food component interference and its possible management is discussed.     

Hypolipidemic activity of Anethum graveolens in rats

The aerial parts of Anethum graveolens (dillweed) are used in Iran as a hypolipidemic agent. The scientific basis for its use has yet to be established. In this study the hypolipidemic activity of dill powder and its essential oil (its most important fraction) were evaluated in male Wistar rats (180 +/- 20 g) fed a high cholesterol diet. Anethum graveolens essential oil (AGEO) was prepared by hydrodistillation and analysed using GC/MS. AGEO had a yield of 2% and GC/MS analysis showed that alpha-phellandrene (32%), limonene (28%) and carvone (28%) were its major components. Daily oral administration of AGEO to rats at doses of 45, 90 and 180 mg/kg for 2 weeks significantly and in a dose-dependent manner reduced total cholesterol, triglyceride and low density lipoprotein cholesterol (LDL-C). AGEO also increased significantly high density lipoprotein cholesterol (HDL-C). Anethum graveolens powder when added to the diet of animals showed similar effects on serum lipids. It is concluded that Anethum graveolens has significant lipid lowering effects and is a promising cardioprotective agent.     

Studies on essential oils: part 10; antibacterial activity of volatile oils of some spices

The essential oils extracted from the seeds of seven spices, Anethum graveolens, Carum capticum, Coriandrum sativum, Cuminum cyminum, Foeniculum vulgare, Pimpinella anisum and Seseli indicum have been studied for antibacterial activity against eight pathogenic bacteria, causing infections in the human body. It has been found that the oil of C. capticum is very effective against all tested bacteria. The oil of C. cyminum and A. graveolens also gave similar results. These oils are equally or more effective when compared with standard antibiotics, at a very low concentration.     

Investigation of Lepechinia graveolens for its antioxidant activity and phenolic composition

A bioguided separation of Lepechinia graveolens (Reg.) Epling. (Lamiaceae) for antioxidant activity was carried out. The ethyl acetate fraction (EAF) from the methanolic extract was chromatographed on Sephadex LH-20 affording five active fractions. The radical scavenging activity of each fraction, as well as that of the isolated compounds, was tested using three different methods. The major isolated antioxidant compounds were identified as luteolin-7-O-glucuronide, rosmarinic acid, and rosmarinic acid methyl ester by means of 1H and 13C NMR and mass spectrometry. Twenty other minor phenolic compounds were determined by liquid chromatography-negative electrospray ionization tandem mass spectrometry. They included hydroxycinnamic acid derivatives, flavonoids and phenolic diterpenes. The major phenolic compound was found to be rosmarinic acid, which was quantitatively determined by high-performance liquid chromatography (HPLC)-diode array detector (DAD). The content of rosmarinic acid was 2.8% (referred to dry weight), this amount being around 30% of the total phenolic content (TPH) of the crude extract. It can be concluded that the antioxidant activity of Lepechinia graveolens was mainly due to rosmarinic acid, which allows this plant species to be considered as a potential new source of this well known natural antioxidant.     

The essential oil of Senecio graveolens (Compositae): chemical composition and antimicrobial activity tests.

The chemical composition of the essential oil obtained from Senecio graveolens (Compositae) was analyzed by GLC-MS and the components identified were: isovaleraldehyde, alpha-pinene, alpha-phellandrene, alpha-terpinene, p-cymene, sabinene, gamma-terpinene, 1-methyl-4-isopropenylbenzene, terpinolene, terpinen-4-ol, piperitenone, alpha- and beta-eudesmol. The investigation by the agar-well diffusion method of the antimicrobial activity of the essential oil proved that it has antibacterial effects on Micrococcus luteus ATCC 9341, oxacillin-sensitive and oxacillin-resistant Staphylococcus aureus, as well as antifungal effects on clinically isolated Candida albicans. The minimal inhibitory concentration (MIC) values for M. luteus, oxacillin-sensitive S. aureus and C. albicans were 8.73, 10.91 and 2.13 x 10(-2) mg/ml, respectively. The antimicrobial activity related to known antibiotics was calculated. These results would be compatible with a potential concentration-dependent selectivity of antifungal effect of S. graveolens essential oil. Minimal bactericidal concentration (MBC) is above 87.3 mg/ml. Thus the MBC:MIC ratio would be clearly higher than 1 (above 8), indicating a bacteriostatic effect of the essential oil.     

'Buchu' -Agathosma betulina and Agathosma crenulata (Rutaceae): a review

South Africa has offered the world two indigenous aromatic plants from which commercially important natural products have been developed: Pelargonium graveolens (and its hybrids) the source of geranium oil and Agathosma betulina, from which 'Buchu' oil is produced. Despite the historical use of 'Buchu' and the commercial interest developed around this coveted indigenous resource the (limited) research has not been coherently assembled. This overview aims to unite aspects on the botany, traditional and modern day uses, chemistry and pharmacological data on 'Buchu' which is undeniably one of South Africa's most renowned botanical assets.     

天竺葵花抗氧化作用的研究

 目的：研究天竺葵花的抗氧化作用。方法：用化学发光法研究天竺葵花粗提液对超氧阴离子自由基（O〈sub〉2〈/sub〉^-）和羟在自由基（·OH）的清除作用。用分光光度法研究它对1,1一二苯基-2-苦肼基自由基（DPPH·）的清除作用。结果：天竺葵花具有很强的清除自由基活性。其粗提液清除O〈sub〉2〈/sub〉^-的IC〈sub〉50〈/sub〉分别为3.5μg·ml〈sup〉-1〈/sup〉（红花）,3.0μg·ml〈sup〉-1〈/sup〉(粉花),1.6μg·ml〈sup〉-1〈/sup〉(浅粉花);清除·OH 的IC〈sub〉50〈/sub〉分别为5.7μg·ml〈sup〉-1〈/sup〉(红花),4.2μg·ml〈sup〉-1〈/sup〉（粉花）,3.8μg·ml〈sup〉-1〈/sup〉(浅粉花);清除DPPH.的IC〈sub〉50〈/sub〉分别为12μg·ml〈sup〉-1〈/sup〉(红花),8.3μg·ml〈sup〉-1〈/sup〉(粉花),5.7μg·ml〈sup〉-1〈/sup〉(浅粉花),均与市售茶多酚的清除能力相近（其IC〈sub〉50〈/sub〉。分别为：1.1,4.1,5.4μg·ml〈sup〉-1〈/sup〉）。结论：天竺葵花可能成为一种新的高效天然杭氧化剂。     

施用不同中药渣对甘草生长及有效成分含量的影响

中药产业产生了大量的中药渣,目前中药废渣多数被当作生活垃圾处理,造成环境的污染和资源的浪费。针对上述情况,该文采用研究了不同中药渣对甘草生长及有效成分含量的影响,结果表明施用白术药渣能显著提高甘草地上部分生物量、叶片数、分枝数和地下部分的根粗、根重,增加幅度达到0.53~1.81倍。施用连翘药渣效果次之,其中甘草地上部分生物量、分枝数和地下部分根粗、根重较对照增加幅度为0.43~1.13倍。而且,施用白术药渣还能显著提高甘草根部甘草酸的含量,同对照相比,提高幅度为1.54倍。白术渣、苦参渣、连翘药渣、麦芽渣4种中药渣均能显著提高甘草地上部分生物量,提高幅度为0.43~1.81倍。综合而言,作者推荐在甘草种植生产施用适量白术药渣和连翘药渣,以有效提高药材品质和产量。     

Medicinal properties and conservation of Pelargonium sidoides DC.

Ethnopharmacological relevance

Pelargonium sidoides DC. (Geraniaceae), a popular medicinal plant used in traditional medicine in the treatment of gastrointestinal ailments has been transformed into a phytopharmaceutical (EPs^® 7360) for treating respiratory tract infections. The increasing international demand for Pelargonium sidoides has led to localised overexploitation of its wild populations in southern Africa. The aim of the review is to provide a synthesis of the current state of scientific knowledge on the phytochemical, pharmacological and toxicological properties of Pelargonium sidoides as well as the potential role of plant biotechnology in its conservation. The review highlights knowledge gaps in these research areas.

Materials and Methods

A comprehensive literature search involving mainly electronic and library sources of information were used to collate and synthesise published data.

Results

Experimental results from in vitro studies indicate that bioactive phytochemical constituents of Pelargonium sidoides may not possess a direct antimicrobial effect, but instead act by interfering with microbial binding to host cell receptors, inhibition of key enzymes and the production of antimicrobial effector molecules such as nitric oxide and interferons (IFNs) by the host cells. Furthermore, clinical evaluations in randomised, double-blind, placebo-controlled trials have demonstrated the beneficial effect of Pelargonium sidoides in the treatment of respiratory tract infections with few side effects. However, there is lack of adequate information on the safety evaluation of the plant. On the other hand, the increasing demand for Pelargonium sidoides has led to localised illegal harvesting of wild plants.

Conclusions

Pharmacological data reported in literature suggest that Pelargonium sidoides shows a beneficial effect in the treatment of respiratory tract infections. However, more studies are required to elucidate the mode of action of the active constituents exhibited in the treatment of respiratory tract infections and other health conditions caused by microbial attack. Furthermore, the pharmacological usefulness of Pelargonium sidoides must take cognisance of the broader context involving the need for conservation-friendly approaches in its utilisation. In this regard, plant biotechnology applications can play a meaningful role in a holistic conservation strategy.