各种金丝桃的细胞培养产生金丝桃素、假金丝桃素和类黄酮化合物

金丝桃素(hypericin)、假金丝桃素(pseudohypericin)及类黄酮化合物都有医疗作用。各种金丝桃属植物都能产生金丝桃素类、类黄酮化合物、原花青素类(procyanidins)和鞣质类等化合物,但种间有     

黑龙江省两种金丝桃属植物理化鉴别特征

目的：为了探讨黑龙江省两种金丝桃属植物长柱金丝桃(Hypericum ascyron L．)、乌腺金丝桃(H．attenuatum Choisy．)理化鉴别特征。方法：分别采用黄酮、皂苷、鞣质及金丝桃素的鉴别试验。结果：黄酮定性反应均为阳性；皂苷定性反应表明均含三萜皂苷；鞣质的定性反应表明它们所含鞣质为缩合鞣质；金丝桃素的定性反应表明乌腺金丝桃含金丝桃素。结论：二者理化鉴别特征有一定差别．能通过化学鉴别方法予以鉴别。     

金丝桃素在非人灵长类动物血浆中的药代动力学及脑脊液穿透力

金丝桃素 (ｈｙｐｅｒｉｃｉｎ)是由植物黑点叶金丝桃(Ｈｙｐｅｒｉｃｕｍｐｅｒｆｏｒａｔｕｍ ,国外俗称为圣约翰野菜 )提取的一种天然色素 ,其化学结构为 4 ,5 ,7,4′ ,5′ ,7′ 六羟基 2 ,2′ 二甲基 中萘并二蒽酮 ,在古代就知金丝桃属植物的提取物有药用价值。近年来由于发现金丝桃素具有抗抑郁症、抗病毒和抗癌作用而重新受到重视。在体外观察到金丝桃素对于胶质瘤、表皮样癌、白血病、小鼠乳腺癌细胞系的细胞都具有杀伤作用。在体外它通过抑制蛋白激酶Ｃ而抑制人恶性胶质细胞瘤细胞系的生长。目前已批准进行口服金丝桃素治疗复发性…     

甲基贯叶金丝桃素在贯叶金丝桃抗抑郁机理中的作用

此项研究显示,在贯叶金丝桃提取物抑制突触小体摄取单胺类神经递质的作用中,贯叶金丝桃素不是惟一的活性成分。问苯三酚类成分甲基贯叶金丝桃素(拟)(adhyper-forin)和其他未知的亲脂成分对该植物的临床效果亦具有一定作用。     

金丝桃素纳米制剂的设计与发展

金丝桃素是从金丝桃属植物中分离得到的一种高效的天然光敏剂和靶向抗肿瘤药,但由于本身的疏水性使其应用受到限制。本文对金丝桃素的性质及在纳米制剂中的抗肿瘤应用进行了概述,结合当前的研究现状,为金丝桃素纳米制剂的设计和发展提供了科学依据。     

金丝桃苷在植物中的分布及其含量测定

金丝桃苷广泛存在于多种植物中,具有重要的生物活性。本文综述了金丝桃苷在植物中的分布以及影响植物中金丝桃苷含量的因素,为进一步开发和利用金丝桃苷提供了科学依据。     

抗艾滋病药用植物——贯叶金丝桃

当前,威胁人类健康的艾滋病病毒感染者在全球已愈3,340万人,而我国也呈上升趋势,到1998年10月已超过1000万人,我省自1993年发现有艾滋病毒感染者以来,已超过5千人以上。人们在医疗过程中发现愈来愈多的化学药品表现出严重的毒副作用,医药界已把目光转移到大自然,希望能从中发现更多更高效无毒的天然药物。国外新近又推出了一种新的植物——贯叶金丝桃,提取物金丝桃素,已成为引人注目的抗艾滋病新药。本属植物全世界有4to多种,我国有50余种,贵州多达间种,尤其是贯叶金丝桃,具有开发价值和应用前景。贯叶金丝桃为藤黄科金丝桃属…     

正交设计贯叶金丝桃提取物制备工艺

贯叶金丝桃（贯叶连翘）是藤黄科植物,全草含金丝桃素伪金丝桃素等苯骈二蒽酮类化合物,具有抗抑郁、抗病毒等药理作用。贯叶金丝桃提取物对轻、中度抑郁症有明显疗效。在德国、英国金丝桃素作为药物上市,用于治疗抑郁抑郁症。从贯叶金丝桃中提取有效成分金丝桃素有一定要求。我们用正交设计对其渗漉用醇浓度、浸渍时间、渗漉液量作了探讨,优选最佳工艺。     

原花青素B2和金丝桃苷对大鼠金丝桃素血浓度的影响

由于金丝桃素水溶性较差,因而该成分仅在高剂量时显示活性。存在于同一植物中的原花青素B2和金丝桃苷虽无活性,但能显著增强金丝桃素的水溶性,提高其生物利用度。作者采用药物动力学方法,研究了原花青素B2或金丝桃苷与金丝桃素合用时是否能改善金丝桃素的水溶性以提高其血浓度。     

贯叶金丝桃的研究

贯叶金丝桃(Hypericum perforatum L.)作为民间草药用于治疗神经疾病、创伤、烧伤、尿路感染已有几个世纪。现代研究证实了其抗菌、抗病毒、抗炎、镇静以及脑化学修饰等方面的活性。新近的研究发现,贯叶金丝桃的两种主要活性成分金丝桃素和假金丝桃素具有很强的抑制艾滋病毒作用,且毒性很低。有报道说动物用了这种植物,会产生光过敏反应,所以美国食品及药物管理局对贯叶金丝桃的所有植物制剂的安全性尚未认可。不过,对人的毒性作用至今还未见报道。     

金丝桃素合酶基因的快速克隆及功能鉴定

金丝桃素合酶能催化大黄素生成金丝桃素,根据已发表的金丝桃素合酶的基因序列,设计了6对引物,通过连续重叠PCR快速克隆得到了金丝桃素合酶基因hyp-1。构建含hyp-1基因的原核表达载体pET32ahyp,将该载体导入大肠杆菌进行诱导表达。SDS-PAGE结果表明,hyp-1基因在大肠杆菌中获得表达;Western blot结果表明,重组的Hyp-1蛋白具有特异的免疫活性,表明hyp-1基因在E.coli中得到了表达。酶促反应表明,Hyp-1确实能催化大黄素形成金丝桃素,上述结果表明,本研究克隆的hyp-1基因是金丝桃素合酶基因,具备催化大黄素形成金丝桃素的能力,从而为通过合成生物学技术制备金丝桃素奠定了物质基础。     

Hypericin--a new antiviral and antitumor photosensitizer: mechanism of action and interaction with biological macromolecules

Hypericin, a naturally occurring pigment, is found in certain species of plants from the genus Hypericum, the most common of which is Saint John's Wort (Hypericum perforatum). Recent interest in hypericin is provoked by the discovery that it possesses extremely high toxicity towards certain viruses notably the class of enveloped viruses that includes human immunodeficiency virus (HIV) and toward tumors, and that this toxicity absolutely requires light. Consequently, a detailed understanding of the interaction of hypericin with cellular components (membranes, proteins, nucleic acids) and with light is of fundamental biological importance. The antiviral and antineoplastic activities of hypericin and its derivatives and its mode of action have been widely studied, in the last two decades. This review is focused on the results obtained in the study of hypericin heteroassociations with biological macromolecules, DNA and human serum albumin in particular. An alternative type of the hypericin photosensitizing activity associated with its ability to produce a photogenerated pH drop is discussed that and discussed in connection with its potential application in photodynamic therapy. In the review, it is also presented how an interdisciplinary approach supported by sophisticated techniques of optical spectroscopy and molecular modeling can be effectively applied for the identification of the specific binding sites of the drug in some biomacromolecules as well as for the determination of the physico-chemical mechanism'of the biological activity of hypericin.     

Cellular mechanisms and prospective applications of hypericin in photodynamic therapy

During the last decades, Photodynamic Therapy (PDT) has been established as a powerful alternative approved by health agencies of several countries for treatment of various malignant and some non-malignant diseases. PDT makes use of the light-induced destruction of target cells by formation of cytotoxic products in the presence of a photosensitizing agent and oxygen. The light-dependent tumor destructive properties of Hypericin have drawn attention to its promising application as a photosensitizer in the frame of PDT. Hypericin is a naturally occurring secondary metabolite in plants of the Hypericum genus, with Hypericum perforatum (St. John's wort) as it is a commonly known representative. This review focuses on the cellular mechanisms of Hypericin-based phototoxicity and provides an outlook for future application of Hypericin as a fluorescing and photosensitizing agent for diagnosis and treatment of cancerous diseases, respectively.     

Progress in the studies on tryptanthrin, an alkaloid of history

Tryptanthrin, an indoloquinazoline alkaloid, was first obtained by sublimation of natural indigo and later isolated from the culture of fungus Candida lipolytica and a variety of other natural sources. Tryptanthrin showed a variety of intriguing biological properties such as antibacterial, antifungal, antiprotozoal, and antiparasitic activities, inhibitory activities against COX-2, 5-LOX, NO synthase and PGE(2) expression, as well as cytotoxic and antitumor activities. Present review covers recent studies on the natural sources, biological activities and mechanisms of their actions, synthesis, structure–activity relationship, and metabolism of tryptanthrin.     

Virucidal activity of hypericin against enveloped and non-enveloped DNA and RNA viruses.

Hypericin is a polycyclic anthrone first isolated from the plant St. Johnswort and was shown to have dramatic anti-retroviral activity against Friend leukemia virus and radiation leukemia virus in mice. Hypericin displayed marginal activity (IC50 = 6 micrograms/ml) against Moloney murine leukemia virus (Mo-MuLV) in vitro. Hypericin did not display selective antiviral activity against herpes simplex virus, influenza A, adenovirus, or poliovirus. The 50% cytotoxic concentration was approximately 25 micrograms/ml. When virus was incubated with hypericin before infecting cells, the drug was virucidal to all enveloped viruses tested (herpes simplex, influenza virus A, and Mo-MuLV) at concentrations of 1.56 micrograms/ml to 25 micrograms/ml. Hypericin was not virucidal to the non-enveloped viruses tested (adenovirus and poliovirus). These data indicate that the mechanism of viral inactivation for hypericin is dependent upon the presence of a viral lipid envelope. In vivo, hypericin (50 mg/ml) was effective against FLV or HSV-1 if incubated with the virus for 1 h at 37 degrees C before infecting mice, but was not effective if pre-incubated with virus for 1 h at 4 degrees C or if administered concurrently with virus.     

金丝桃素提取物对乳腺癌细胞MDA231的光动力杀伤效应研究

目的研究贯叶金丝桃中金丝桃素（HY）提取物对人乳腺癌细胞株MDA231的体外光动力杀伤效应。方法通过测定胞内荧光强度来确定细胞对金丝桃素的吸收，用显微镜观察、MTT法和DNA电泳分析法来研究金丝桃素对细胞的生长抑制作用。结果光活化的金丝桃素对MDA231细胞有显著的体外杀伤效应，其抑制细胞生长的能力与HY的浓度及光照能量密切相关。结论金丝桃素提取物在光照下能明显抑制乳腺癌细胞的生长，金丝桃素用于治疗乳腺癌具有广阔的开发应用前景。     

来源于植物的天然二苯甲酮类化合物的研究现状

天然二苯甲酮是存在于植物中的一类具独特结构的化合物,具有多种生物活性,日益受到国内外学者的关注。综述来源于植物的天然二苯甲酮类化合物的主要结构和分布特点及其生物活性。     

How to make hypericin water-soluble

Hypericin, isolated from Hypericum perforatum, is an effective photodynamic substance as demonstrated by various studies. Practical forms of applications of hypericin solutions for systemic use and introduction into body cavities are, however, lacking. We developed an aqueous solution of hypericin non-covalently bound to polyvinylpyrrolidone (PVP). PVP is a poly-N-vinylamide of various degrees of polymerization and forms of intermolecular crosslinks suitable for diagnostic and therapeutic applications. We used PVP (molecular weights of PVP between 10 kD and 40 kD) as a complex forming agent to prepare hypericin for photodynamic therapy and diagnostics. In pure water, hypericin forms aggregates which are non-soluble and non-fluorescent. The hypericin-PVP complex binds more than 1000 mg of hypericin in presence of 100 g PVP or less and is soluble in 1 liter of pure water. Aqueous complex solutions of hypericin-PVP display a characteristic absorption spectrum and fluorescence emission band around 600 nm wavelength. Varying concentrations of hypericin do not cause a blue- or red-shift in the absorption maximum at 595 nm. Excitation at 200 nm to 500 nm leads to emission at 590 nm; a property conducive to diagnostic investigations both in vitro and in vivo. Furthermore, hypericin-PVP exhibits high photostability in the presence of oxygen and broad band light which ensures reproducible photodynamic therapy and diagnosis. CONCLUSION: Hypericin forms liquid molecular chromophore complexes in water when bound to PVP thus allowing investigations in biological media.