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1.
Hemoglobin mediated cytotoxicity and apoptosis has been evaluated in Tumor necrosis factor‐α (TNF‐α) sensitive cell line, U937 and compared with TNF‐α. Both species of hemoglobin, Hemoglobin A2 and Hemoglobin A0 induced apoptosis and cytotoxicity in U937 cell as measured by flow cytometry and 3‐(4,5‐dihydro‐6‐(4‐(3,4‐dimethoxybenzooyl)‐1‐piperazinyl)‐2(1H)‐quinoline (MTT) assay respectively. Different concentration of Hemoglobin A0 (4 ng/mL to 4000 ng/mL) induced apoptosis ranging from 9% to 16% in U937 cells. 4000 ng/mL hemoglobin A0 showed maximal apoptotic cells. TNF‐α showed 87% apoptotic U937 cells at concentration of 1 pg/mL. HbA0 displayed cytotoxicity in U937 cell line at higher concentration in comparison to TNF‐α. 4000 ng/mL of hemoglobin A0 showed optimal cytotoxic response in U937 cells. A dose response curve was also observed with varying doses of hemoglobin A0. U937 cells pretreated with serum activated LPS for 1 hr and incubated with different concentration of hemoglobin or human TNF‐α for 24 h reduced the cytotoxic effect on U937. Dexamethasone treatment of U937 cells helped in protecting the HbA0 and HbA2 mediated cytotoxicity and anti‐TNF‐α antibody neutralized the hemoglobin mediated apoptosis and cytotoxicity. It is therefore apparent that human hemoglobin shares some of the bioactivities previously ascribed to TNF‐α. Sharing of bioactivities of TNF‐α by hemoglobin is interesting and suggests that cell free hemoglobin can mimic TNF‐α functionally.  相似文献   
2.
多尼培南是一种新型的β-内酰胺类抗生素,它具有较广的抗菌谱,与美罗培南相似,对G 菌、G-菌和厌氧菌均具有超广谱强效的抗菌作用.对某些病原体,如铜绿假单胞菌和耐甲氧西林金葡菌,多尼培南比美罗培南有更强效的抗菌活性.多尼培南在美国和欧洲处于Ⅲ期临床研究,用于治疗医院内的严重细菌感染,已获得美国FDA快通道批准治疗院内获得性肺炎,包括呼吸道相关性肺炎.本文就其化学结构、作用机制、抗菌活性、药代动力学及临床应用作一概述.  相似文献   
3.
王不留行的研究进展   总被引:11,自引:0,他引:11  
目的 介绍植物种子王不留行的研究概况和研究进展.方法 以近年来国内外发展的文献为依据,从化学成分、药理作用及临床应用方面综述了王不留行的研究进展.结果 王不留行及主要成分是止血、治疗妇科疾病及抗肿瘤的良药.结论 王不留行是一种很有研究价值的药用植物.  相似文献   
4.
海洋拟诺卡菌由于其独特的代谢功能,成为海洋放线菌次级代谢产物的重要来源。根据2010-2013年初的海洋放线菌天然产物的统计表明,对拟诺卡菌的研究仅次于链霉菌。本文综述了从2001年的第一个海洋来源的拟诺卡菌天然产物至2018年6月17年间报道的65个海洋拟诺卡菌天然产物的微生物来源、结构及其生物活性。其结构包括吡喃酮类、二酮哌嗪类、多肽类等,其中吡喃酮类化合物是主要类型,占海洋拟诺卡菌天然产物总数的46%;而29%的海洋拟诺卡菌天然产物表现出抑菌、细胞毒、抗炎等生物活性。  相似文献   
5.
片螺素(lamellarin)及其相关的吡咯生物碱是一类从海洋生物中分离得到的具有新颖结构和显著生物活性的海洋生物碱。其结构特征是都具有3,4-二芳基-2-酸酯或酰胺母核。本综述概述了近期关于lamellarin及其相关吡咯生物碱的提取分离、全合成、生物活性及其构效关系等方面的研究。  相似文献   
6.
目的:金莲花由于其清热解毒作用在中药及蒙药中被广泛使用。作为一种药食两用药物,金莲花已经引起了生药学家、药理学家、天然药物学家、营养学家等的广泛兴趣。其化学成分和生物活性研究发展较快,然而也存在一些问题,诸如有效成分的归属问题。这些问题限制了金莲花的进一步开发利用。本文结合本研究组对金莲花的化学成分和生物活性的研究成果,以及近几十年有关金莲花的研究报道,对金莲花的化学成分和生物活性研究进展进行了系统总结,并对存在的问题进行了讨论与展望。  相似文献   
7.
Since ancient times, saffron, the dried stigma of the plant Crocus sativus L. has been extensively used as a spice and food colorant; in folk medicine it has been reputed to be efficacious for the alleviation and treatment of ailments. In addition to the three founded major constituents including crocin, picrocrocin and safranal, presence of carotenoids, carbohydrates, proteins, anthocyanins, vitamins and minerals provide valuable insights into the health benefits and nutritional value of saffron. Of the carotenoids present in saffron, highly water-soluble crocin (mono and diglycosyl esters of a polyene dicarboxylic acid, named crocetin) is responsible for the majority of its color, and appears to possess various health-promoting properties, as an antioxidant, antitumor, memory enhancer, antidepressant, anxiolytic and aphrodisiac. It is also worth noting that the crocin principle of saffron exhibited high efficacy along with no major toxicity in experimental models. We would be remiss to not consider the great potential of saffron and crocin, which benefits the cuisine and health of human life throughout the world. The present study provides a comprehensive and updated report of empirical investigations on bioactivities and biological characteristics of crocin.  相似文献   
8.
目的 从700多株海洋沉积物分离得到的细菌中筛选安莎类抗生素和6-脱氧己糖(6DOH)糖基化修饰的次级代谢产物产生菌.方法 以3-氨基-5-羟基苯甲酸(AHBA)合酶基因和dTDP-葡萄糖-4,6-脱水酶基因为靶标,分别进行安莎类抗生素和6DOH糖基化修饰的次级代谢产物产生菌的分子筛选.对AHBA合酶及dTDP-葡萄糖-4,6-脱水酶基因阳性的菌株发酵液及提取物进行抗菌、抗肿瘤、抗病毒活性分析.采用利福霉素抗性及氢氧化钠显色初步鉴定安莎类化合物;采用α-萘酚硫酸显色初步鉴定6DOH糖基化修饰的化合物.利用16S rRNA序列对部分阳性菌株进行系统发育分析.结果 共获得39株AHBA合酶基因阳性和10株dTDP-葡萄糖-4,6-脱水酶基因阳性菌株.阳性菌株中,78%具有不同程度的生物活性.化学初步鉴定结果表明:49%的AHBA合酶基因阳性菌株产生安莎类化合物:50%的dTDP-葡萄糖-4,6-脱水酶基因阳性菌株产生6DOH糖基化修饰的化合物.系统发育分析表明,大多数阳性菌株属于放线菌中的链霉菌属.结论 基因探针筛选可作为一种合理、有效的方法从海洋细菌中发现活性代谢产物.  相似文献   
9.
Garcinia kola Heckel – a tropical plant which grows in moist forest, has found wide applications in traditional medicine especially in the West and Central African sub-region. The seeds have been demonstrated to possess numerous bioactivities but research is highly limited on the link between its fractions and the bioactivities. In this work, the methanolic extract of Garcinia kola seeds was subjected to silica gel column chromatography into five fractions ME1–ME5 and the free radical scavenging activities and antioxidant potentials were determined for each fraction using various in vitro models. The ME4 fraction possessed the greatest activities. It was also demonstrated that the ME4 fraction strongly inhibited nitric oxide production in lipopolysaccharide activated macrophage U937 cells. Chromatographic fractionation and spectroscopic analysis of the ME4 fraction revealed the presence of four compounds namely garcinia biflavonoids GB1 and GB2, garcinal and garcinoic acid. These findings show that these four compounds are partly responsible for the great antioxidant potential of Garcinia kola seeds. This gives further evidence to the nutraceutical and pharmaceutical potential of Garcinia kola.  相似文献   
10.
多糖的生物活性及其应用   总被引:13,自引:0,他引:13  
多糖是一种结构复杂的高分子化合物,具有多种生物活性,在生物体内起着重要作用,因此受到人们的关注。现将多糖的生物活性及其在医药领域和保健食品领域的应用现状作一综述。  相似文献   
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