七种中草药提取物抗肿瘤活性部位的筛选研究初报

选取叶下珠、珠子草、千里光、鸦胆子、使君子、冬青和猫爪藤等7种中草药进行提取和初步分离,筛选出有抗肿瘤效果的活性部位,并对其进行初步分析。采用MTT法,以7种中草药醇提物的不同分离部位分别对人肝癌、胃癌、卵巢癌等肿瘤细胞株进行体外增殖抑制作用研究,并以人正常肝细胞株为模型对照跟踪筛选活性部位。结果表明,从7种中草药醇提物中,均获得对肿瘤细胞株具有体外增殖抑制作用的化学分离部位,其中叶下珠和珠子草的乙酸乙酯层和正丁醇层的活性最显著,千里光的乙酸乙酯层、鸦胆子的正丁醇层、使君子和冬青的氯仿层活性次之,猫爪藤氯仿层和冬青的乙酸乙酯层活性较差,其他部位无活性。     

紫威科植物猫爪藤化学成分与生物活性研究进展

紫威科植物猫爪藤常被用作装饰植物,其自然群落主要分布在热带美洲的一些国家,在其它国家移植或归化的猫爪藤因被认为具有生物入侵危害而备受关注。然而,在原产地的一些国家或地区民间则将其作为药物治疗许多病症,如炎症、风湿病、痢疾、性病、疟疾、毒蛇咬伤等。近年来,这些国家的研究者就此对猫爪藤进行了较多的化学成分和药理作用的相关研究,本文主要综述了这方面的研究进展,以期使人们进一步了解猫爪藤具有药用价值的一面,从而引导和促进对其进行开发和利用而不要简单的当作有害入侵物种来进行对待。     

藏药砂生槐种子提取物抑菌和细胞毒活性的初步研究

砂生槐是我国西藏高原一种特有植物,是一种极为宝贵的药用植物资源.我们首次从砂生槐种子中获得氯仿、95%乙醇、75%乙醇和水提取物,用琼脂扩散实验测定其抑菌活性和用MTT法测定其对肿瘤细胞的细胞毒效应,表明氯仿提取物和95%乙醇提取物具有广谱的抑菌活性,抑菌活性较强的是氯仿提取物.各种提取物显示出浓度依赖性的细胞毒效应,氯仿、95%乙醇、75%乙醇和水提取物对胃癌SGC-7901细胞系的LC50分别是4.5、1.4、1.9和41.7 mg/mL,抑制胃癌SGC-7901细胞增殖作用较强的成分是砂生槐种子95%乙醇提取物.这一发现为开发砂生槐这一宝贵植物资源的药用价值提供了重要的依据.     

奶子藤属植物中生物碱研究进展

奶子藤属植物为傣族传统常用药材,含有大量结构复杂,生物活性良好的生物碱类成分。本文针对奶子藤属植物中已分离鉴定的95个生物碱及其体外抗肿瘤和抗HIV活性研究进行了系统综述,为更加合理地开发利用奶子藤属植物资源提供参考依据。     

女贞子提取物主要活性组分及其抗丙型肝炎病毒复制活性分析

中药女贞子(Ligustrum lucidum,LL)具有肝保护和抗炎症作用.本研究分析女贞子提取物对丙型肝炎病毒(hepatitis C virus, HCV)复制的影响及其活性成分. 薄层层析法分离女贞子水提取物,获得5个分离组分. Real-time RT-PCR 和Western印迹发现,分离组分1和2 抑制HCV JFH1细胞感染模型中的JFH1病毒复制. 分离组分的高效液相色谱(high-performance liquid chromatography,HPLC)分析表明,熊果酸和齐墩果酸可能是组分1 和 2的抗病毒活性成分. 熊果酸和齐墩果酸抗病毒实验发现,熊果酸和齐墩果酸抑制HCV JFH1的复制,它们的选择指数 (SI) 分别为 6.7 和30.8. 这些研究结果表明,女贞子及其化学成分熊果酸和齐墩果酸具有潜在的丙型肝炎治疗价值.     

蒲公英抗肿瘤活性部位的GC-MS分析研究

目的：考察蒲公英提取物对MCF-7增殖作用的影响,研究蒲公英抗肿瘤活性部位的化学成分。方法：采用MTT法比较蒲公英水提物、醇提物和不同极性提取物对MCF-7增殖的影响;以气相色谱．质谱（GC-MS）联用技术对具有抑制MCF-7人乳腺癌细胞增殖的部位进行分离和鉴定。结果：蒲公英水提物和醇提物对MCF-7细胞均有抑制作用,体外最大抑制率分别达到92．95％、93．59％,蒲公英不同极性溶剂提取物中,氯仿部位抑制MCF-7的增殖,且抑制作用高于醇提和水提物,乙酸乙酯和石油醚部位促进MCF-7的增殖。从蒲公英氯仿提取物中鉴定出80种化合物,占其总量的98．07％。结论：蒲公英氯仿部位具有抗肿瘤活性,为蒲公英抗肿瘤活性成分的研究提供了依据,拓展了筛选中药活性成分的方法。     

北青龙衣抗肿瘤谱效关系研究初探

目的:对北青龙衣抗肿瘤谱效关系进行初步研究。方法:采用乙醇冷浸提取,大孔树脂进行初步分离,所得到的各组分用MTT法进行体外细胞毒试验,测定各组分对人胃癌细胞BGC803的抑制活性,并用薄层色谱进行初步谱效关系研究。结果:大孔树脂经30%乙醇洗脱的组分显示较强的细胞毒活性,薄层色谱显示该组分为极性大和极性小的成分的复杂组合。结论:大孔树脂经30%乙醇洗脱的组分在北青龙衣抗肿瘤活性中起重要作用。     

海洋放线菌124092细胞毒活性和化学成分研究

采用MTT法对海洋放线菌124092正己烷提取物进行细胞毒活性筛选,结果显示对小鼠B16黑色素瘤细胞有一定的生长抑制活性。用硅胶真空柱层析法将正己烷提取物粗分为6个组分（Fr1～Fr6）,细胞毒活性追踪显示Fr6组分为活性部分。为确定其中的活性成分,运用GC／MS对脯组分的化学成分进行了分析,结果显示其主要成分为：棕榈酸（Palmitic acid,11．76％）、油酸（Oleic acid,12．16％）、亚油酸（Linoleic acid．14．77％）和乳杆（菌）酸（Lactobacillic acid,61．31％）。据文献报道棕榈酸、油酸、亚油酸均对小鼠腹水瘤细胞具有细胞毒活性,亚油酸还对人肺腺癌细胞具有抑制作用。     

翅果藤的细胞毒活性和化学成分研究

对翅果藤(Myriopteron extensum (Wight)K.Schum)的甲醇提取物及其不同的极性部位进行的细胞毒活性筛选发现乙酸乙酯、正丁醇部分具有一定的细胞毒活性。首次对其成分的研究分离得到7个化合物,通过波谱分析鉴定为β—谷甾醇,齐墩果酸,α—香树素乙酸酯,β—香树素乙酸酯,羽扇豆烷乙酸酯,乌沙甙元和胡萝卜甙。进一步的活性测试和化学研究仍在进行。     

胶陀螺的光敏活性组分

用石油醚、氯仿、乙酸乙酯和丙酮对胶陀螺子实体进行梯度提取,得到的粗提物做光敏活性药理试验,结果表明:胶陀螺的氯仿和乙酸乙酯粗提取物有明显的光敏活性。将氯仿和乙酸乙酯的粗提物分别用不同比例的氯仿—甲醇进行反复柱层析,同时配合光敏活性药理试验,得到6个有光敏活性的组分,分别为c2、c3、c4、c5、c6和c11。将6个组分合并后继续分离,最终得到1个有橙黄色荧光点的成分,对其进行光敏活性药理试验,结果证明其为胶陀螺的光敏活性成分。     

Candidates for biocontrol of Macfadyena unguis-cati in South Africa: biology, host ranges and potential impact of Carvalhotingis visenda and Carvalhotingis hollandi under quarantine conditions

Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) was introduced as an ornamental in South Africa, but is fast becoming an important invasive plant in many areas. It is difficult to control the plant chemically and mechanically. The first biocontrol agent, the chrysomelid Charidotis auroguttata (Boheman), has been released. It established at some release sites, but numbers have so far remained low. Additional biocontrol agents were sought to augment C. auroguttata. The potential host ranges of two foliage feeding lace bugs, Carvalhotingis visenda (Drake and Hambleton) and C. hollandi (Drake) (Hemiptera: Tingidae) were evaluated on the basis of nymphal no-choice and adult multi-choice tests involving 23 plant species in 11 families. In no-choice tests, nymphs of both species were able to survive and complete development on M. unguis-cati only, and adults of both species only fed and oviposited on M. unguis-cati during the adult multi-choice tests. Host specificity tests thus confirm that the tingids are highly host specific biocontrol agents, and will not pose risk to any non-target plants in South Africa. A study to determine the potential impact of C. hollandi nymphal feeding on M. unguis-cati showed a significant decrease in the chlorophyll contents of leaves when compared to those of control plants. These studies indicate that, once released, the two lace bug species could contribute significantly to the biological control of M. unguis-cati in South Africa.     

Comparison of cytotoxic activities betweenin vitro and field grown plants ofTyphonium flagelliforme (Lodd.) blume

Anin vitro cytotoxicity screening of theTyphonium flagelliforme extracts indicated high cytotoxicity effect on human lung carcinoma NCl-H23 cells and human mammary gland carcinoma T-47D cells, but the extracts were not active on human liver carcinoma HepG2 cells. NCl-H23 cells were more susceptible toT. flagelliforme extracts than T-47D cells. EDP₅₀ values of the hexane fractions of the mature plant and thein vitro plantlet ofT. flagelliforme on NCl-H23 cells were less than 2 μg/mL Extract from the mature plant was relatively more cytotoxic than the one fromin vitro plantlet except for the hexane fraction. The chloroform and butanol fraction of the mature plant had higher cytotoxicity effect than the fraction fromin vitro plantlet on NCl-H23 cells. All the 3 fractions (hexane, chloroform, and butanol) of the mature plant exhibited higher cytotoxicity effects on human mammary gland carcinoma T-47D cells than the 3 fractions ofin vitro plantlet. However, the human liver carcinoma cells were resistant toT. flagelliforme extracts except for higher concentration of hexane fractions of both the mature and thein vitro plants and the chloroform fraction of the mature plant. Micropropagated plantlets ofT. flagelliforme could hence be used as herbal materials for the treatment of human lung and breast cancers.     

Antibacterial and immuno-modulatory activity of ethanol extracts from Lespedeza sp. during Helicobacter pylori infections

Chemical therapeutics targeted against H. pylori may lead to host toxicity and pathogen eradication failures. In this study, ethanolic extracts from five Lespedeza sp. plants were shown to inhibit the gastric-pathogen H. pylori and to modulate cytokine production. Disc agar diffusion assays showed that Lespedeza sp. ethanol extracts possess potent anti-H. pylori activity. Among the five plant extracts, the extracts from L. cyrtobotrya demonstrated the highest anti-H. pylori effect. The growth inhibitory effect against H. pylori was initiated after six h of treatment with plant extracts and the effect remained for a continuous period of 48 h. Incubation of the gastric cells infected with H. pylori with 1.25 to 50 mg/mL of sp. plant extracts resulted in a reduction of the production of cytokine IL-8. The plant ethanol extracts generally had little influence on AGS cell viability, indicating their safety for the treatment of bacterial infections. Three active fractions of L. cyrtobotrya also demonstrated similar anti-H. pylori and immuno-modulatory effects. Taken together, these results provide evidence that Lespedeza sp. plant extracts might be potential sources of new host friendly anti-H. pylori agents.     

Lavandula stoechas L. subsp. stoechas,a New Herbal Source for Ursolic Acid: Quantitative Analysis,Purification and Bioactivity Studies

In this study, methanol, ethanol, methanol-dichloromethane (1 : 1, v/v), acetone, ethyl acetate, diethyl ether, and chloroform extracts of lavender (Lavandula stoechas L. subsp. stoechas) were prepared by maceration, and the ursolic acid contents in the extracts were determined quantitatively by HPLC analyses. The present results show that the methanol-dichloromethane (1 : 1, v/v) solvent system is the most efficient solvent system for the extraction of ursolic acid from the plant sample with the highest yield (2.22 g/100 g plant sample). In the present study, a new practical method for the isolation of ursolic acid from polar extracts was also demonstrated for the first time. The inhibition effects of the extracts and ursolic acid were also revealed on α-glycosidase, acetylcholinesterase, butyrylcholinesterase, and human carbonic anhydrase I and II enzymes by determining IC₅₀ values for the first time. The extracts and ursolic acid acted as potent antidiabetic agents by strongly inhibiting the α-glycosidase activity, whereas they were found to be very weak neuroprotective agents. In view of the present results, L. stoechas and its major metabolite, ursolic acid, can be recommended as a herbal source to control postprandial blood sugar levels and prevent diabetes by delaying the digestion of starch in food.     

23种中草药的体外抗菌活性筛选研究

为考察中草药抗菌物质基础筛选出活性提取物,该研究通过80%乙醇冷浸和95%乙醇回流提取制备23种中草药的提取物,采用琼脂扩散法测量抑菌圈直径,用微量液体培养基倍比稀释法测定最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal/fungicidal concentration,MBC/MFC),并测定了提取物对临床4种常见病原菌体外抗菌活性。结果表明:紫珠草、千斤拔、黄龙尾等9种中草药对金黄色葡萄球菌有较强的抑菌活性,其MIC/MBC值除个别菌是12.5 mg·mL~(-1)外,其他都在0.09～3.12 mg·mL~(-1)之间;千斤拔、大红袍、过江龙等5种中草药对铜绿假单胞菌有较强抑菌活性,其MIC/MBC值在3.12～12.5 mg·mL~(-1)之间;紫珠草、千里光、石楠等13种中草药对大肠埃希菌有较强的抑菌活性,其MIC/MBC值在0.09～6.25 mg·mL~(-1)之间;八角对白色念珠菌有较强抑菌活性,其MIC/MFC值在0.78～12.5 mg·mL~(-1)之间。23种中草药的抗细菌活性较好,尤其是千斤拔、大红袍、过江龙、八角、黄药子对金黄色葡萄球菌、大肠埃希菌、铜绿假单胞菌都具有较好的抑菌活性,具有广谱抗菌活性;但对真菌抑菌效果不明显,仅有八角对白色念珠菌有抑菌活性。此外,提取溶剂浓度、提取温度和提取时间对中草药的提取率和活性均有影响,冷提稍优于热提。     

Transgenic indica rice expressing Mirabilis jalapa antimicrobial protein (Mj-AMP2) shows enhanced resistance to the rice blast fungus Magnaporthe oryzae

Mj-AMP2, a knottin-type antimicrobial peptide, in vitro inhibits the growth of several plant pathogenic fungi including Magnaporthe oryzae. We demonstrate that transgenic rice (Oryza sativa L.) plants expressing the Mj-AMP2 gene show enhanced resistance to M. grisea, the causal agent of the rice blast disease. Mj-AMP2 was efficiently expressed and the level of Mj-AMP2 ranged from 0.32% to 0.38% of the total protein in the transgenic rice plants. In vitro inhibitory activity assays with the crude protein extract from transgenic rice indicated that the Mj-AMP2 protein produced was biologically active. Constitutive expression of Mj-AMP2 in transgenic rice reduces the growth of M. grisea by 63% with respect to untransformed control plant, and no effect on plant phenotype was observed. Transgene expression of Mj-AMP2 gene was not accompanied by an induction of pathogenesis-related (PR) gene expression indicating that the transgene product itself is directly active against the pathogen. The results presented in this study suggest that the Mj-AMP2 gene could be a useful candidate for protection of rice plants against the rice blast fungus M. grisea.     

白花地胆草的抗菌活性成分研究

从白花地胆草(Elephantopus tomentosus Linn.)全草的乙醇提取物中分离得到9个化合物,通过波谱分析,鉴定其结构分别为:表木栓醇(1)、羽扇豆醇(2)、6-deoxyisojacreubin(3)、桦木酸(4)、熊果酸(5)、阿魏酸(6)、3-甲酰吲哚(7)、半夏酸(8)和30-醛基羽扇豆醇(9)。所有化合物均为首次从白花地胆草中分离得到。用滤纸片琼脂扩散法测定上述化合物的抗菌活性,结果表明,化合物6和7对金黄色葡萄球菌的生长有抑制作用,化合物6和8对烟草青枯病菌的生长有抑制作用。     

酸枣果提取物在体内外对抗生素的增效作用及机制研究

作者研究团队先前从酸枣果的氯仿提取物中精制得到其低极性范围的活性组合物Fr.2a,发现Fr.2a与多种抗生素联用显示出广泛的协同抗菌作用。该研究在Fr.2a的基础上利用硅胶柱层析对酸枣果氯仿提取物中其他极性范围内的活性成分进行了分离纯化,得到精制物Fr.B,并对精制物Fr.B进行GC MS、核磁共振氢谱、红外光谱分析,以确定Fr.B的组成成分;通过抗菌谱分析和细胞通透性分析,以明确Fr.B的抗菌增效谱和抗菌增效机制;采用熔和法将精制物Fr.B制备成软膏,通过小鼠伤口感染模型评价该软膏对抗生素的增效效果。结果表明：(1)由酸枣果氯仿提取物进一步精制得到的Fr.B组分,主要包含反油酸、油酸、顺 10 十六碳烯醇、棕榈酸等脂肪酸类化合物。(2)Fr.B分别与庆大霉素、妥布霉素、氨苄青霉素、氯霉素、红霉素、夫西地酸、制霉菌素、酮康唑和两性霉素B等多种抗生素联用时显示出广泛的协同抗菌作用。(3)Fr.B可破坏细胞膜和细胞壁的完整性而增强细菌细胞的通透性。(4)在体内和体外Fr.B均能显著增强红霉素对耐甲氧西林金黄色葡萄球菌(MRSA)的杀菌作用,从而提高红霉素对MRSA菌株引起的伤口感染的治疗效果。研究表明,本研究所得到的Fr.B具有广谱的抗菌增效活性,能够增强红霉素对伤口耐药菌感染的治疗效果。该研究结果为克服微生物对抗生素的耐药性提供了新的思路和解决方案。     

Potential of Ginkgo biloba L. leaves in the management of hyperglycemia and hypertension using in vitro models

Leaves from four different Ginkgo biloba L. trees (1 and 2 – females; 3 and 4 – males), grown at the same conditions, were collected during a period of 5 months (from June to October, 2007). Water and 12% ethanol extracts were analyzed for total phenolics content, antioxidant activity, phenolic profile, and the potential in vitro inhibitory effects on α-amylase, α-glucosidase, and Angiotensin I-Converting Enzyme (ACE) enzymes related to the management of diabetes and hypertension. The results indicated a significant difference among the trees in all functional benefits evaluated in the leaf extracts and also found important seasonal variation related to the same functional parameters. In general, the aqueous extracts had higher total phenolic content than the ethanolic extracts. Also, no correlation was found between total phenolics and antioxidant activity. In relation to the ACE inhibition, only ethanolic extracts had inhibitory activity.     

In vitro cytostatic and immunomodulatory properties of the medicinal mushroom Lentinula edodes

Lentinula edodes, known as “shiitake” is one of the widely used medicinal mushrooms in the Orient. Antitumour activity of extracts of this mushroom has been widely demonstrated in animals and humans. However, this activity was shown to be host mediated and not by direct cytotoxic activity to cancer cells. This study demonstrates cytotoxic and cell growth inhibitory (cytostatic) effect of aqueous extracts of the mushroom on MCF-7 human breast adenocarcinoma cell line using an MTT cytotoxicity assay. Such effect was demonstrated with fruit body and mycelial extracts, the difference being that there was no significant suppression on normal cells with the latter. Furthermore mycelial extracts did not induce any cytostatic effect in both cancer and normal cell lines based on a DNA synthesis assay. The significant suppression of the proliferation of cancer cells was reflected by the comparatively low IC₅₀ values and the simultaneous higher respective values on normal fibroblast cells. The immunostimulatory activity of both fruit body and mycelial extracts was tested by the lymphocyte transformation test (LTT), which is based on the capacity of active immunomodulators to augment the proliferative response of rat thymocytes to T mitogens in vitro. Both fruit body and mycelial preparations were able to enhance the proliferation of rat thymocytes directly and act as co-stimulators in the presence of the T-mitogen PHA. Interestingly both extracts, similarly to zymosan showed SI_comit/SI_mit ratios of about 2, indicating adjuvant properties. Overall L. edodes aqueous extracts have demonstrated direct inhibition of the proliferation of human breast cancer cells in vitro and immunostimulatory properties in terms of mitogenic and co-mitogenic activity in vitro.