无花果叶提取物抗氧化活性的研究

目的研究无花果叶提取物的抗氧化活性。方法采用乙醇冷浸与溶剂分相萃取相结合的方法获得无花果叶的石油醚相、乙酸乙酯相和正丁醇相提取物,采用Fenton反应产生羟自由基(·OH),采用邻苯三酚自氧化法产生超氧阴离子自由基(O2·-),测定无花果叶提取物对二苯代苦味胼基自由基(DPPH·),·OH和O2·-的清除能力,并与特丁基对苯二酚(TBHQ)和2,6-二叔丁基-4-甲基苯酚(BHT)进行比较。结果无花果叶提取物的石油醚相、乙酸乙酯相和正丁醇相对DPPH.的EC50分别为121.3,125.0和550.9μg/mL;对.OH的EC50分别为470.0,350.0和610.0μg/mL;对O-.2的EC50分别为140.0,210.0和150.0μg/mL。结论无花果叶提取物各相均有抗氧化活性,且其活性与浓度呈剂量依赖关系。     

银杏叶中银杏内酯A分离纯化工艺研究

目的:建立一种简易的白银杏叶中提取、分离和纯化银杏内酯A的方法.方法:依次通过乙醇溶液搅拌提取、乙酸乙酯萃取、大孔树脂吸附与洗脱及结晶和重结晶对银杏叶中的银杏内酯A进行分离纯化.以银杏内酯A的得率和纯度为指标,对银杏内酯A的分离纯化工艺进行优选.结果:确定银杏内酯A提取、分离和纯化的最佳工艺条件为:将银杏叶乙醇提取物混...     

Investigation of biological activity of polar extracts isolated from Phlomis crinita Cav ssp. mauritanica Munby

The lyophilized infusion, the methanol, the ethyl acetate, and the total oligomer flavonoid (TOF)-enriched extracts prepared from the dried leaves of Phlomis crinita Cav. ssp. mauritanica Munby were investigated for the contents of flavonoids, tannins, coumarines and steroids. Antibacterial activity was investigated toward five bacterial strains. An inhibitory effect was observed against Staphyllococcus aureus and Enterococcus feacalis, and the minimal inhibitory concentrations ranged from 2.5 to 5 mg/mL of extract. The tested extracts exhibit an important free radical scavenging activity toward the 1,1-diphenyl 2-picrylhydrazyl (DPPH) free radical; with IC₅₀ values of 30.5, 6, 32, and 31.5 μg/mL, respectively, in the presence of lyophilized infusion, the TOF, the methanol, and the ethyl acetate extracts. Genotoxic and antigenotoxic properties of the different extracts were studied by using the SOS chromotest with Escherichia coli PQ37. The lyophilized infusion and TOF extracts obtained from P. crinita ssp. mauritanica showed no genotoxicity, whereas methanol and ethyl acetate extracts are considered as marginally genotoxic. On the other hand, we showed that each extract inhibited the mutagenicity induced by aflatoxin B1 (AFB1) (10 μg/assay) and nifuroxazide (NF) (10 μg/assay). The ethyl acetate extract showed the strongest level of protection toward the genotoxicity induced by both directly and indirectly genotoxic NF and AFB1. These tests proved that the lyophilized infusion possesses an antiradical activity likewise, it showed no genotoxic effect; that is why we choose this extract to assess its antiulcerogenic activity by using an ethanol-induced ulcerogenesis model in the rat. This test demonstrates that 300 mg/kg of a P. crinita ssp. mauritanica lyophilized infusion was more effective than the reference compound, cimetidine.     

滇黄芩茎叶乙醇提取物及其不同溶剂萃取部位的抗氧化和降脂活性研究

目的:研究滇黄芩茎叶乙醇提取物及其不同溶剂萃取部位的抗氧化活性和降脂活性.方法:取滇黄芩茎叶用95％乙醇回流提取,得乙醇提取物;取上述提取物,依次用石油醚、乙酸乙酯、正丁醇萃取,回收溶剂得到不同溶剂萃取部位.以维生素C(Vc)为阳性对照,采用羟基自由基、超氧阴离子自由基、1,1-二苯基-2-三硝基苯肼(DPPH)自由基...     

黄芪药材利尿作用的谱效关系研究

目的 阐述黄芪的高效液相色谱(HPLC)图谱与利尿药效的相关性,表征黄芪药材的药效物质基础。方法 对不同产地的10批黄芪药材乙酸乙酯部位进行HPLC指纹图谱研究;以小鼠的排尿量为指标来研究利尿作用：氢氯噻嗪(0.6 g·kg^-1)为阳性对照组,小鼠灌胃乙酸乙酯部位的浸膏7 d(1.4 g·kg^-1);采用灰关联度分析方法研究其谱效关系。结果 黄芪乙酸乙酯部位的利尿作用是其所有化学成分共同作用的结果,各特征峰代表各自化学成分,其对利尿作用贡献的大小顺序(按特征峰编号)：P₇>P₆>P₈>P₅>P₄>P₂>P₁>P₃。其中4号峰为毛蕊异黄酮,7号峰为芒柄花素。结论 乙酸乙酯部分含较多中等极性的黄酮类化合物,能明显提高小鼠的排尿量,其HPLC指纹图谱与利尿作用之间有一定对应关系,这为进一步探讨黄芪对肾炎蛋白尿的治疗作用奠定了基础。     

Estimation of Total Phenols and Flavonoids in Extracts of Actaea spicata Roots and Antioxidant Activity Studies

Actaea spicata Linn. (Ranunculaceae) has been traditionally used for the treatment of various ailments such as rheumatism, inflammation, nerve diseases, lumbago, scrofula and chorea, but no systematic phytochemical and pharmacological work has ever been carried out on this potential plant. Preliminary phytochemical screening showed presence of phenols and flavonoids in A. spicata. Thus, the present investigation was undertaken to estimate total phenols and flavonoids in methanol extract of A. spicata roots, and its ethyl acetate fraction. In vitro antioxidant activity was also evaluated in the methanol extract and ethyl acetate fraction using DPPH method. Ethyl acetate fraction was found to contain twice the content of flavonoids and phenols in comparison to methanolic extract, whereas phenolic content in methanol extract was approximately similar to ethyl acetate fraction. A significant antioxidant activity, i.e., mean percentage inhibition of DPPH radical was observed in methanol extract and ethyl acetate fraction at the concentration of 10 μg/ml and 5 μg/ml respectively. Finally, it was suggested that polyphenols are responsible for antioxidant activity of A. spicata.     

Bioassay-Guided Isolation of a Potent Platelet-Activating Factor Antagonist Alkenylresorcinol from Ardisia elliptica

In the course of our search for novel platelet-activating factor (PAF) antagonists from medicinal plants, the methanol extract of the leaves of Ardisia elliptica Thunb. was investigated for its inhibitory effects on PAF receptor binding to rabbit platelets using ³H-PAF as a ligand. The methanol extract showed inhibitory activity of 53.9% and its ethyl acetate, n-butanol, and methanol fractions exhibited 48.6%, 39.0%, and 22.0% inhibition, respectively. Bioassay-guided fractionation of the ethyl acetate fraction led to the isolation of a new alkenylresorcinol, 5-(Z-heptadec-4′-enyl)resorcinol, together with 5-pentadecylresorcinol. The alkenylresorcinol showed a strong inhibition with an IC₅₀ value of 7.1 µM. The structures of the compounds were elucidated by spectroscopic techniques.     

Screening of Methanol Extract and Ethyl Acetate Fraction of Abies webbiana Lindl. for Neuropharmacological Activities

Despite a long traditional of use of Abies webbiana Lindl. (Talispatra; family-Pinaceae) in the treatment of mental disorders, the plant has not been investigated systematically to validate its traditional claims. Thus, the present investigation was undertaken with an objective to investigate neuropharmacological activities of methanol extract of Abies webbiana aerial parts and its ethyl acetate fraction. Properly identified aerial parts were defatted with petroleum ether and then extracted with methanol in a Soxhlet apparatus. Ethyl acetate fraction was prepared by partitioning methanol extract with ethyl acetate using standard procedure. In acute toxicity study, no mortality was observed in animals after oral administration of 2 g/kg dose of methanol extract. The methanol extract (200 or 400 mg/kg, p.o.) and ethyl acetate fraction (25 or 50 mg/kg, p.o.) were evaluated for antianxiety, anticonvulsant, antidepressant, sedative, antistress and analgesic activities using well established models. The methanol extract and ethyl acetate fraction of Abies webbiana aerial parts exhibited significant antianxiety, anticonvulsant, antidepressant, sedative, antistress and analgesic activities with respect to control. Preliminary phytochemical screening showed presence of flavonoids in bioactive ethyl acetate fraction of Abies webbiana aerial parts. It is finally concluded that flavonoids are the bioactive constituents responsible for most of neuropharmacological activities of Abies webbiana.     

Protective effects of flavonoids and extract from <Emphasis Type="Italic">Vellozia kolbekii</Emphasis> Alves against oxidative stress induced by hydrogen peroxide in yeast

Two flavonoids 3,5,7,3′,4′-pentahydroxy-6-prenylflavonol (1) and 3,5,7,3′,4′-pentahydroxy-8-methyl-6-prenylflavonol (2) were isolated from the ethyl acetate extract of sheaths of Vellozia kolbekii Alves (Velloziaceae). This is the first time that compound 2 has been described. The crude extract and flavonoids were found to be active as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavengers and were able to the increase tolerance of the eukaryotic microorganism Saccharomyces cerevisiae to oxidative stress generated by H₂O₂. The protective effect was correlated with a reduction in the oxidation of proteins and lipids. In addition, flavonoids isolated from Velloziaceae showed an inhibitory effect on mutations in p53, which is mutated and nonfunctional in more than 50% of cases of human cancer.     

Phytochemical profile,antioxidant and cytotoxic potential of Parkinsonia aculeata L. growing in Saudi Arabia

Parkinsonia aculeata L. growing in Saudi Arabia was investigated for its phytochemical profile, antioxidant, and cytotoxic properties. UPLC-ESI-MS/MS was employed as a powerful technique for the characterization of secondary metabolites from a hydroalcoholic extract, dichloromethane, and ethyl acetate fractions of P. aculeata L. aerial parts. Sixty-nine compounds (flavonoids, anthocyanins, phenolics and fatty acids) were detected and characterized; flavonoids were the abundant components in the analyzed samples. The dichloromethane fraction was rich in phenolics as vanillic acid hexoside, flavonols as 3,7-dimthylquercetin, and flavones as 3′-hydroxymelanettin. However, the ethyl acetate fraction was rich in flavonoid-C-glycosides as luteolin-8-C-β-D-glucoside (orientin) and apigenin-8-C-glucoside (vitexin), flavonoid- O, C-diglycosides such as luteolin 7-O-[6′'-dihydrogalloyl]-glucosyl-8-C-pentosyl-(1 → 2)-glucoside and 2′'-O-rhamnosyl isoorientin. These compounds were identified for the first time in dichloromethane and ethyl acetate fractions of Saudi P. aculeata L.Additionally, all the samples were assessed for antioxidant activity using DPPH radical scavenging method and for cytotoxic activity through MTT assay. Accordingly, the most active fraction was the ethyl acetate which showed the highest antioxidant activity (SC₅₀ = 57.4 ± 1.2 μg/mL) compared with the positive control, ascorbic acid (SC₅₀ = 12.4 ± 0.5 μg/mL) and moderate cytotoxicity against HepG-2 (hepatocellular carcinoma) and MCF-7 (breast carcinoma) cell lines with IC₅₀ = 56.9 ± 3.1 and 95.8 ± 3.8 μg/mL, respectively compared with cisplatin (IC₅₀ = 3.67 ± 0.22 and 5.71 ± 0.57 μg/mL, respectively for both cell lines). The antioxidant and cytotoxic activities may be attributed to the presence of high percentage of phenolic compounds and hydroxylated flavonoids detected in ethyl acetate fraction using UPLS-ESI-MS/MS.     

溪黄草黄酮类化合物抑制亚硝化反应活性的研究

目的研究溪黄草黄酮类化合物对亚硝化反应的抑制作用。方法根据最佳提取工艺条件提取得到3个主要的黄酮类化合物,研究其对亚硝化反应的抑制作用。结果溪黄草总黄酮提取率可达91.98%,水溶性部分阻断亚硝胺的合成及清除亚硝酸盐作用较强,分离得到的3个黄酮类化合物中芦丁的抑制作用较强,对亚硝胺的合成的最大阻断率可达91.5%,对亚硝酸盐的最大清除率可达89.2%。结论溪黄草黄酮类化合物具有抑制亚硝化反应的活性。     

Antigenotoxic and Free Radical Scavenging Activities of Extracts from Moricandia arvensis

This study evaluates genotoxic and antigenotoxic effects of extracts from leaves of Moricandia arvensis, which are used in traditional cooking and medicines. Extracts showed no genotoxicity when tested with the SOS Chromotest using E. coli PQ37 and PQ35 strains, except for the total oligomers flavonoids enriched extract. Petroleum ether and methanol extracts are the most active in reducing nitrofurantoin genotoxicity, whereas methanol and total oligomers flavonoids enriched extracts showed the most important inhibitory effect of H₂O₂ genotoxicity. In addition, these two extracts showed important free radical scavenging activity toward the DPPH^· radical, whereas the chloroform extract exhibited the highest value of TEAC against ABTS^+· radical.     

Chemical composition and biological activities of extracts and essential oil of Boswellia dalzielii leaves

Context: Boswellia dalzielii Hutch. (Burseraceae) is an aromatic plant. The leaves are used for beverage flavouring.

Objective: This study investigates the chemical composition and biological activities of various extracts.

Materials and methods: The essential oil was prepared via hydrodistillation. Identification and quantification were realized via GC-MS and GC-FID. Consecutive extractions (cyclohexane, dichloromethane, ethyl acetate and methanol) were carried out and various chemical groups (phenolics, flavonoids, tannins, antocyanins and sugar) were quantified. The volatile compounds of organic extracts were identified before and after derivatization. Antioxidant, antihyperuricemia, anti-Alzheimer, anti-inflammatory and anticancer activities were evaluated.

Results: In the essential oil, 50 compounds were identified, including 3-carene (27.72%) and α-pinene (15.18%). 2,5-Dihydroxy acetophenone and β-d-xylopyranose were identified in the methanol extract. Higher phenolic (315.97?g GAE/kg dry mass) and flavonoid (37.19?g QE/kg dry mass) contents were observed in the methanol extract. The methanol extract has presented remarkable IC_50?=_?6.10?mg/L for antiDPPH, 35.10?mg/L for antixanthine oxidase and 28.01?mg/L for anti-5-lipoxygenase. For acetylcholinesterase inhibition, the best IC₅₀ (76.20 and 67.10?mg/L) were observed, respectively, with an ethyl acetate extract and the essential oil. At 50?mg/L, the dichloromethane extract inhibited OVCAR-3 cell lines by 65.10%, while cyclohexane extract inhibited IGROV-1 cell lines by 92.60%.

Discussion and conclusion: Biological activities were fully correlated with the chemical groups of the extracts. The ethyl acetate and methanol extracts could be considered as potential alternatives for use in dietary supplements for the prevention or treatment of diseases because of these extracts natural antioxidant, antihyperuricemic and anti-inflammatory activities.     

Functional components in Scutellaria barbata D. Don with anti-inflammatory activity on RAW 264.7 cells

The objectives of this study were to determine the variety and amount of various functional components in Scutellaria barbata D. Don as well as study their anti-inflammatory activity on RAW 264.7 cells. Both ethanol and ethyl acetate extracts were shown to contain the functional components including phenolics, flavonoids, chlorophylls, and carotenoids, with the former mainly composed of phenolics and flavonoids, and the latter of carotenoids and chlorophylls. Both extracts could significantly inhibit (p < 0.05) the production of lipopolysaccharide-induced nitric oxide, prostaglandin E₂, interlukin-6, and interlukin-1β, as well as the expressions of phosphor extracellular signal-regulated kinase and phosphor-c-Jun N-terminal kinase (p-JNK), but failed to retard tumor necrosis factor-α expression. Both ethanol and ethyl acetate extracts had a dose-dependent anti-inflammatory activity on RAW 264.7 cells. Furthermore, the anti-inflammatory efficiency can be varied for both ethanol and ethyl acetate extracts, which can be attributed to the presence of different varieties and amounts of functional components, as mentioned above. This finding suggested that S. Barbata extract may be used as an anti-inflammatory agent for possible future biomedical application.     

Phytochemical analysis of ethyl acetate extract from Astragalus corniculatus Bieb. and brain antihypoxic activity

Dry ethyl acetate extract containing flavonoids was obtained from above-ground parts of Astragalus corniculatus Bieb. Seven flavonoids were isolated and identified as rutin, hyperoside, isoquercitrin, narcissin, quercetin, kaempferol and isorhamnetin for the first time. The extract was found to be practically non-toxic (acute oral toxicity > 5 g kg(-1) in mice). The extract was investigated for antihypoxic activity in two models of experimental hypoxia--haemic and circulatory. Antihypoxic activity was especially pronounced in the model of circulatory hypoxia. This effect may be attributed, at least in part, to the presence of flavonoids in the extract.     

Antiinflammatory and analgesic activities of Thesium chinense Turcz extracts and its major flavonoids, kaempferol and kaempferol-3-O-glucoside

The ethyl acetate, chloroform extracts, and the two flavonoids kaempferol 1 and kaempferol-3-O-glucoside 2 isolated from whole plants of Thesium chinense Turcz were investigated for their antiinflammatory and analgesic activities. For the antiinflammatory activity, carrageenan-induced hind paw edema and xylene-induced mouse ear edema models, and for the analgesic activity, the acetic acid-induced abdominal constriction test was used. The ethyl acetate extract and two flavonoids showed significant (p<0.05 and p<0.01) and dose-dependent antiinflammatory and analgesic activity. The chloroform extract was inactive in the assay.     

Liquid extraction of ginseng and bilberry leaves

The number of diabetes patients continuously increases. Combined application of synthetic drugs and phytopreparations can decrease the negative side effects of drugs. The aim of this study was to create a new antidiabetic drug in the form of a liquid extract based on dry bilberry (Vaccinium myrtillus L.) and ginseng leaves. Quantification of flavonoids in bilberry leaves was carried out using a spectrophotometric method (425 nm); of tannins, by titration. Extraction performed with 50% aqueous ethanol isolated the maximum amount of principal active substances (polyphenols, ginsenosides). The optimum extraction conditions were determined as 4.5 h (time of infusion) and 5 h (time of displacement). Characteristics of the liquid extract are a brown fluid with distinctive odor, bittersweet, ethanol content 46.70 ± 0.31%, and solid residue content 35.23 ± 0.27%. The tannin content that was determined qualitatively using the reaction with FeNH₄(SO₄)₂ · 12H₂O (development of a dark-green color) and with 1% gelatin solution (formation of impurities) was 13.97 ± 0.22%. The flavonoid content that was determined by TLC (silica gel; butanol: acetic acid:water, 60:20:20; 3 spots of flavonoids) was 0.79 ± 0.03%. The panaxozide content that was determined by TLC (silica gel; butanol:ethanol:NH₄OH (25%), 9:2:5; 8 spots of panaxozides) was 0.29 ± 0.02%. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 42, No. 3, pp. 20–24, March, 2008.     

白及不同提取部位对小鼠止血活性实验

目的确定白及的止血活性部位,为其止血活性成分的筛选提供线索和依据。方法用70%乙醇(EtOH)对白及原药材进行渗漉提取,然后,依次用石油醚(Pet)、乙酸乙酯(EtOAc)、正丁醇(n-BuOH)对醇浸膏进行萃取,分别制得Pet部分、EtOAc部分、n-BuOH部分和H2O部分,通过测定小鼠凝血时间和出血时间,考察其活性部位。结果 n-BuOH部分和H2O部分具有止血作用,而EtOAc部分具有延长凝血、出血时间作用。结论白及中具有止血作用的活性成分主要存在于n-BuOH部分和H2O部分,而EtOAc部分具有活血作用。     

Characterization of bioactive compounds and ameliorative effects of Ceratonia siliqua leaf extract against CCl4 induced hepatic oxidative damage and renal failure in rats

Ceratonia siliqua is a typical Mediterranean plant, mainly used in food and Tunisian traditional folk medicine. Among the tested extracts, the ethyl acetate fraction (EACs) exhibited the highest total phenolic and flavonoids content. The antioxidant activity in vitro systems showed a more significant potent free radical scavenging activity of this extract than other analysis fractions. The HPLC finger print of EACs active extract showed the presence of six phenolic compounds. The in vivo results showed that oral administration of CCl₄ enhanced levels of hepatic and renal markers (ALT, AST, ALP, LDH, γ-GT, urea and creatinine) in the serum of experimental animals. It also increased the oxidative stress markers resulting in increased levels of the lipid peroxidation with a concomitant decrease in the levels of enzymatic antioxidants (SOD, CAT, GPx) in both liver and kidney. The pre-treatment of experimental rats with 250 mg/kg (BW) of the EACs, by intraperitoneal injection for 8 days, prevented CCl₄ induced disorders in the levels of hepatic and kidney markers. The biochemical changes were in accordance with histopathological observations suggesting a marked hepatoprotective and nephroprotective effect of the EACs extract.