Analysis of antibacterial activity and mechanism of polypyridyl ruthenium complex / 中国药理学通报

Aim To analyze the antibiotic activity and mechanism of a polypyridyl ruthenium complex. Meth-ods The antibacterial activity of [ ( Phen ) 2 Ru ( dp-pz) ] ( PF6 ) 2 was determined by MIC and MBC value. Based on a fluorescent activity of this complex, the flu-orescent emission spectra was used to analyze the com-bination of complex to DNA. Then the competition combination was analyzed between complex and Gold View to DNA. Lastly, gel electrophoresis of DNA was applied to detect the combination situation between complex and DNA. Results This kind of polypyridyl ruthenium complex showed a significant antibacterial activity with a minimum antibacterial conentration of 0. 2~0. 4 g · L-1 . That was caused by the combina-tion and distortion of DNA due to the activity of this complex. Conclusion The antibacterial activity and the mechanism of antibacterial activity about [ ( Phen) 2 Ru( dppz) ] ( PF6 ) 2 are confirmed in this re-search, which provides a good foundation for the devel-opment of such class of compound.

Efeito protetor do complexo de rutênio (II) (cis-[RuCl(qui)(bpy)2]PF6) contra a lesãogástrica induzida por naproxeno: possível papel regulador da enzima guanilato ciclase solúvel

Os AINEs são um dos principais agentes que contribuem para a patogênese da úlcera gastrintestinal e representam um importante fator etiológico por serem comum enteutilizados na prática clínica. Objetivo: Avaliar o efeito protetor do complexo de rutênio (II)(cis-[RuCl(qui)(bpy)2]PF6), contra a lesão gástrica induzida por na proxeno (NPX) em camundongos. Métodos: Foram utilizados camundongos Swiss (18-22g). Mensuramos os níveis de GMPc incubando amostras de tecidos gástricos com DMSO, com o complexo de Ru (II) e com ODQ, 30 μm de cada composto, por 5 minutos. Os grupos avaliados foram: grupo controle que recebeu CMC, grupo veículo, em que foi administrado NPX (300 mg/kg)e o que recebeu complexo de Ru (II), todos por gavagem. Os animais foram tratados com o complexo de Ru (II), nas doses de 0,3, 3 e 30 mg/kg. Após 30 minutos, seguiu-se com a indução da lesão com NPX. Seguindo o mesmo protocolo,avaliou-se o efeito do composto em estudo e de seus precursores, na dose de 3mg/kg, por gavagem.Verificou-se o efeito do composto na adesão e rolamento leucocitários; seguindo os protocolos descritos, tanto o rolamento quanto a adesão foram avaliados 3h após a indução de gastropatia e de modulação com ODQ (10 mg/kg) por gavagem. Analisou-se o efeito do complexo de Ru (II)em artérias mesentéricas de ratos wistar(200-250g) pré-contraídas com fenilefrina(PHE)(0,3 μM). Simulou-sea ligação entre o composto e a enzima GCs a partir de recursos disponíveis em site que contém banco de dados de proteínas...

NSAIDs contribute to the pathogenesis of gastrointestinal ulcers and represent an important etiologic factor because iscommonly used in clinical practice. Aim:To evaluate the protective effect of the ruthenium complex (II) (cis-[RuCl(qui)(bpy)2]PF6), against the gastric damageinduced by naproxen(NPX)in mice. Methods: Swiss mice were used (18-22g). Measure the GMPc levels incubating samples of gastric tissues with DMSO, with the complex of RU (II) and with ODQ, 30 μm of each compound, for 5 minutes. The groups evaluated were: control group that received CMC, group vehicle, in which was administered NPX (300 mg/kg) and who received complex of RU (II), all by gavage. The animals were treated with the complex of RU (II), in the doses of 0.3, 3 and 30 mg/kg. After 30 minutes, was followed with the induction of the lesion with NPX. Following the same protocol, it was evaluated the effect of the compound and its precursors, in dose of 3mg/kg, by gavage. It was verified theeffect of compound in accession and leukocyte bearing; following the protocols described, both the bearing for accession were evaluated 3h after the induction of gastropathy and modulation with ODQ (10 mg/kg) by gavage. It examined the effect of the complex of RU (II) in mesenteric arteries of Wistar rats (200-250 g) pre-contracted with phenylephrine (PHE) (0.3 μM). Simulated-If the connection between the compound and the enzyme GCs from resources available in the site that contains the database of proteins...

Efeitos de compostos naturais, sintéticos e da fototerapia antifúngica sobre Candida tropicalis resistente ao fluconazol / Effects of natural compounds, synthetic and herbal medicine on Candida tropicalis antifungal fluconazole-resistant

A candidíase é uma infecção oportunista provocada por diversas espécies de fungos do gênero Candida, frequentemente encontrados integrando a microbiota, da superfície cutânea, no trato gastrointestinal e cavidades mucosas do ser humano desde o seu nascimento. A incidência das infecções fúngicas sistêmicas têm aumentado consideravelmente nas últimas décadas em função do grande número de pacientes com SIDA, a grande quantidade de transplantes e condições crônicas como o câncer, a terapia prolongada com imunossupressores e o uso de agentes corticosteroides. Além disso, a exposição prolongada aos antifúngicos azólicos promove a seleção de patógenos resistentes. No presente estudo avaliou-se a atividade antifúngica do complexo Rutênio-pirocatecol (RPC) frente a um isolado clinico de Candida tropicalis resistente ao fluconazol. A metodologia empregada para os testes de susceptibilidade foi de acordo com o documento M27-A3 do National Committee for Clinical Laboratory Standards (NCCLS, 2008). Esplenócitos de camundongos Balb/c foram obtidos de forma asséptica para avaliar a citotoxicidade do composto para células de mamíferos. O estresse oxidativo promovido pelo composto foi avaliado através da reação ao ácido tiobarbitúrico (TBARS) e ensaios de fluorescência com a sonda diclorodihidrofluoresceína diacetato (DCFH2DA). O Calcofluor White foi empregado para avaliar a integridade da parede celular. A análise ultraestrutural foi realizada através da microscopia eletrônica de varredura e transmissão. Os resultados encontrados para os testes de atividade antifúngica foram analisados através do teste estatístico ANOVA e pós-teste Dunnett. Os resultados encontrados para os testes de atividade antifúngica do RPC mostraram uma Concentração Inibitória de 50% (IC50) de 20,3 μM, enquanto em esplesnócitos a concentração efetiva de 50% foi de 325 μM mostrando um índice de seletividade igual a 16...

Candidiasis is an opportunistic infection caused by several species of fungi of the genus Candida, often found is the microbiota, on the skin, gastrointestinal tract and mucous cavities of the human beings birth. The incidence of systemic fungal infections have increased considerably in recent decades due to the large number of AIDS patients, the large number of transplants and chronic conditions such as cancer, prolonged therapy promotes the selection of resistant pathogen with immunosuppressant and corticosteroid agents. Also prolonged exposure azole antifungals to make them strong candidates for patients resistance. In the present study we evaluated the antifungal activity of Ruthenium-pyrocatechol complex (RPC) against a clinical isolate of Candida tropicalis resistant to fluconazole. The methodology for susceptibility testing was in accordance with the M27-A3 document of there National Committee for Clinical Laboratory Standards (NCCLS, 2008). Splenocytes from Balb/c mice were obtained aseptically to evaluate the cytotoxicity of the compound to mammalian cells. Oxidative stress caused by the compound was assessed by reaction to thiobarbituric acid (TBARS) and fluorescence assays with the probe diclorodihidrofluoresceína diacetate (DCFH2DA). The Calcofluor White was used to evaluate the integrity of the cell wall. The ultrastructural analysis was performed by scanning and transmission electron microscopy. The results for the antifungal activity tests were analyzed using ANOVA and pos-test Dunnett test statistic. The results for the tests of antifungal activity of the RPC showed a 50% inhibitory concentration (IC50) of 20.3 μM while in splenocytes the 50% effective concentration was 325 μM showing a selectivity index of 16...

Identification of mechanisms involved in the relaxation of rabbit cavernous smooth muscle by a new nitric oxide donor ruthenium compound

PURPOSE: The aim of this study was to evaluate the relaxation in vitro of cavernous smooth muscle induced by a new NO donor of the complex nitrosil-ruthenium, named trans-[Ru(NH3)4(caffeine)(NO)]C13 (Rut-Caf) and sodium nitroprusside (SNP). MATERIALS AND METHODS: The tissues, immersed in isolated bath systems, were pre-contracted with phenilephrine (PE) (1 µM) and then concentration-response curves (10-12 - 10-4 M) were obtained. To clarify the mechanism of action involved, it was added to the baths ODQ (10 µM, 30 µM), oxyhemoglobin (10 µM), L-cysteine (100 µM), hydroxicobalamine (100 µM), glibenclamide, iberotoxin and apamine. Tissue samples were frozen in liquid nitrogen to measure the amount of cGMP and cAMP produced. RESULTS: The substances provoked significant relaxation of the cavernous smooth muscle. Both Rut-Caf and SNP determined dose-dependent relaxation with similar potency (pEC50) and maximum effect (Emax). The substances showed activity through activation of the soluble guanylyl cyclase (sGC), because the relaxations were inhibited by ODQ. Oxyhemoglobin significantly diminished the relaxation effect of the substances. L-cysteine failed to modify the relaxations caused by the agents. Hydroxicobalamine significantly diminished the relaxation effect of Rut-Caf. Glibenclamide significantly increased the efficacy of Rut-Caf (pEC50 4.09 x 7.09). There were no alterations of potency or maximum effect of the substances with the addition of the other ion channel blockers. Rut-Caf induced production of significant amounts of cGMP and cAMP during the relaxation process. CONCLUSIONS: In conclusion, Rut-Caf causes relaxation of smooth muscle of corpus cavernosum by means of activation of sGC with intracellular production of cGMP and cAMP; and also by release of NO in the intracellular environment. Rut-Caf releases the NO free radical and it does not act directly on the potassium ion channels.

Nitric oxide synthesis and biological functions of nitric oxide released from ruthenium compounds

During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO) as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC) modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP) production, which in turn leads to protein kinase G (PKG) activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca2+ signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could contribute to vascular diseases. Nitrosyl ruthenium complexes have been studied as a new class of NO donors with potential therapeutic use in order to supply the NO deficiency. In this context, this article shall provide a brief review of the effects exerted by the NO that is enzymatically produced via endothelial NO-synthase (eNOS) activation and by the NO released from NO donor compounds in the vascular smooth muscle cells on both conduit and resistance arteries, as well as veins. In addition, the involvement of the nitrite molecule as an endogenous NO reservoir engaged in vasodilatation will be described.

Electrogenerated chemiluminescence sensor for the determination of metoclopramide using ordered mesoporous carbon for immobilizing tris(2, 2'-bipyridyl) ruthenium / 药物分析学报

A novel electrogenerated chemiluminescence (ECL) sensor for the determination of metoclopramide was developed by employing ruthenium complex as an ECL signal producer and an ordered mesoporous carbon (OMC) material as modified material. The ECL sensor was fabricated by adsorption ruthenium complex into a mixture of OMC and Nafion, which showed good electrochemical and ECL behaviors. It was found that the ECL intensity of the sensor fabricated was greatly enhanced in the presence of metoclopramide. Based on this finding, a highly sensitive and reproducible ECL method was developed for the determination of metoclopramide. The result showed that the ECL intensity was linear with the concentration of metoclopramide in the range from 1.0×10-10 to 5.0×10-7M and the detection limit was 3×10-11M. The ECL sensor exhibited a long-term stability and a fine reproducibility with relative standard deviation of 1.0 % for 1.0×10-10M metoclopramide in 18 continuous determinations. The developed method has been applied to the determination of metoclopramide in tablet samples with satisfactory results.

Electrogenerated chemiluminescence sensor for the determination of metoclopramide using ordered mesoporous carbon for immobilizing tris (2, 2′-bipyridyl) ruthenium / 西安交通大学学报·英文版

A novel electrogenerated chemiluminescence (ECL) sensor for the determination of metoclopramide was developed by employing ruthenium complex as an ECL signal producer and an ordered mesoporous carbon (OMC) material as modified material. The ECL sensor was fabricated by adsorption ruthenium complex into a mixture of OMC and Nafion, which showed good electrochemical and ECL behaviors. It was found that the ECL intensity of the sensor fabricated was greatly enhanced in the presence of metoclopramide. Based on this finding, a highly sensitive and reproducible ECL method was developed for the determination of metoclopramide. The result showed that the ECL intensity was linear with the concentration of metoclopramide in the range from 1.0×10-10 to 5.0×10-7 M and the detection limit was 3×10 -11 M. The ECL sensor exhibited a long-term stability and a fine reproducibility with relative standard deviation of 1.0 % for 1.0×10 -10 M metoclopramide in 18 continuous determinations. The developed method has been applied to the determination of metoclopramide in tablet samples with satisfactory results.

New nitric oxide donors based on ruthenium complexes

Nitric oxide (NO) donors produce NO-related activity when applied to biological systems. Among its diverse functions, NO has been implicated in vascular smooth muscle relaxation. Despite the great importance of NO in biological systems, its pharmacological and physiological studies have been limited due to its high reactivity and short half-life. In this review we will focus on our recent investigations of nitrosyl ruthenium complexes as NO-delivery agents and their effects on vascular smooth muscle cell relaxation. The high affinity of ruthenium for NO is a marked feature of its chemistry. The main signaling pathway responsible for the vascular relaxation induced by NO involves the activation of soluble guanylyl-cyclase, with subsequent accumulation of cGMP and activation of cGMP-dependent protein kinase. This in turn can activate several proteins such as K+ channels as well as induce vasodilatation by a decrease in cytosolic Ca2+. Oxidative stress and associated oxidative damage are mediators of vascular damage in several cardiovascular diseases, including hypertension. The increased production of the superoxide anion (O2-) by the vascular wall has been observed in different animal models of hypertension. Vascular relaxation to the endogenous NO-related response or to NO released from NO deliverers is impaired in vessels from renal hypertensive (2K-1C) rats. A growing amount of evidence supports the possibility that increased NO inactivation by excess O2- may account for the decreased NO bioavailability and vascular dysfunction in hypertension.

Relaxation of rabbit corpus cavernosum smooth muscle and aortic vascular endothelium induced by new nitric oxide donor substances of the nitrosyl-ruthenium complex

INTRODUCTION: Endothelial dysfunction characterized by endogenous nitric oxide (NO) deficiency made 56 percent of patients affected with erectile dysfunction decline treatment with PDE-5 inhibitors. New forms of treatment are currently being developed for this group of patients. MATERIALS AND METHODS: The study compared the effect of sodium nitroprusside (SNP) and two substances of the nitrosyl-ruthenium complex, cis-[Ru(bpy)2(SO3)(NO)]PF-6-9 ("FONO1”) and trans-[Ru(NH3)4(caffeine)(NO)]C13 ("LLNO1”) on relaxation of rabbit corpus cavernosum smooth muscle and aortic vascular endothelium. The samples were immersed in isolated baths and precontracted with 0.1 µM phenylephrine (PE) and the corresponding relaxation concentration/response curves were plotted. In order to investigate the relaxation mechanisms involved, 100 µM ODQ (a soluble guanylate cyclase-specific inhibitor), 3 µM or 10 µM oxyhemoglobin (an extracellular NO scavenger) or 1 mM L-cysteine (a nitrosyl anion-specific scavenger) was added to the samples. RESULTS: All the NO donors tested produced a significant level of relaxation in the vascular endothelium. In corpus cavernosum samples, FONO1 produced no significant effect, but LLNO1 and SNP induced dose-dependent relaxation with comparable potency (pEC50 = 6.14 ± 0.08 and 6.4 ± 0.14, respectively) and maximum effect (Emax = 82 percent vs. 100 percent, respectively). All NO donors were found to activate soluble guanylate cyclase, since the addition of the corresponding inhibitor (100 µM ODQ) completely neutralized the relaxation effect observed. The addition of oxyhemoglobin reduced the relaxation effect, but did not inhibit it completely. In aortic vascular endothelium 3 µM oxyhemoglobin decreased the relaxation effect by 26 percent on the average, while 10 µM oxyhemoglobin reduced it by over 52 percent. The addition of 100 µM L-cysteine produced no significant inhibiting effect. CONCLUSIONS: These results suggest that LLNO1...