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ABSTRACT: The cis-[Ru(bpy)(2)(py)NO(2)](PF(6)) specie (RuBPY) has been used as nitric oxide (NO) delivery agent. It is an NO reservoir and it is thermodynamically stable in aqueous solution. This study aimed to evaluate the NO specie generated by RuBPY as compared to NO released from sodium nitroprusside (SNP) and to study the cellular mechanisms specially focusing the activation of soluble guanylyl-cyclase (sGC), K(+) channels and the cell membrane hyperpolarization, which are the main targets for NO-inducing vascular relaxation. NO generated by RuBPY and the vascular smooth muscle cell (VSMC) membrane potential were measured by confocal microscopy. The cellular mechanisms of aorta relaxation were investigated using K(+) channel blockers and sGC inhibitor. NO released from RuBPY was higher than NO released from SNP. RuBPY released only radicalar NO(0) and SNP released both NO(-) and NO(0). The concentration-effect curves for RuBPY-induced relaxation was shifted to the right by inhibition of sGC with ODQ and by the non-selective blockade of K(+) channels with TEA. The simultaneous combination of ODQ and TEA abolished the vasorelaxation induced by RuBPY. The membrane potential measured by the sensitive dye 4-Di-ANNEPS demonstrated that RuBPY induces cell membrane hyperpolarization. Taken together, our results indicate that the large amount of NO(0) specie generated by RuBPY induces vasorelaxation due to activation of sGC, K(+) channels sensitive to TEA, and cell membrane hyperpolarization. These results indicate that NO(0) generated from RuBPY can also directly activate the K(+) channels in an independent way of sGC.
European journal of pharmaceutical sciences: official journal of the European Federation for Pharmaceutical Sciences 01/2013; · 2.61 Impact Factor
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ABSTRACT: Over 6 million people die annually in the world because of cancer. Several groups are focused on studying cancer chemoprevention approaches. Resveratrol, a polyphenol, at high dosages, has been reported as antitumor and chemopreventive. However, it has a dose-dependent effect on cell death, even on some cancer cells.
Our aim was to investigate this dose-dependent effect on human bladder carcinoma ECV304 cells during oxidative stress condition.
For this purpose, ECV304 cells incubated with different Resveratrol concentrations were analyzed as for their metabolic rate, membrane permeability, DNA fragmentation, anti/proapoptotic protein levels and phosphatidylserine exposure after oxidative stress.
Resveratrol induced cell death at high concentrations (>20 μM), but not at low ones (0.1-20 μM). Pretreatment with 2.5 μM protected the cells from oxidative damage, whereas 50 μM intensified the cell death and significantly increased Bad/Bcl-2 ratio (proapoptotic/antiapoptotic proteins). Resveratrol was able to modulate NO and PGE(2) secretion and performed an anti-adhesion activity of neutrophils on PMA-activated ECV304 cells.
Resveratrol at high doses induces cell death of ECV304 cells whereas low doses induce protection. Modulation of Bcl-2 protein induced by Resveratrol could be mediating this effect. This information about the role of Resveratrol on cancer alerts us about its dose-dependent effects and could lead the design of future chemoprevention strategies.
Maturitas 03/2012; 72(1):72-8. · 2.77 Impact Factor
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ABSTRACT: Nitric oxide (NO)-donors are pharmacologically active substances that in vivo or in vitro release NO. Their most common side effect is headache caused by cerebral vasodilatation. We previously demonstrated that the new NO-donor Ru(terpy)(bdq)NO](3+) (Terpy), synthesized in our laboratory, induces relaxation of rat aorta. This study aimed to verify the effect of Terpy and sodium nitroprusside (SNP) in basilar artery. We conducted vascular reactivity experiments on endothelium-denuded basilar rings. The concentrations of iron (Fe) and ruthenium (Ru) complex were analyzed in basilar artery lysates after incubation with NO donors by mass spectrometry. We also evaluated the NO released from SNP and Terpy by using confocal microscopy. Interestingly, Terpy did not induce relaxation of the basilar artery. SNP induced relaxation in a concentration-dependent way. NO donors cross the membrane of vascular smooth muscle and entered the cell. In spite of its permeability, Terpy did not release NO in the basilar artery. Otherwise, SNP released NO in the basilar artery cells cytoplasm. Taken together, our results demonstrate that the new NO donor (Terpy) failed to release NO and to induce relaxation in the basilar artery. The NO donor SNP induces vascular relaxation due to NO release in the vascular smooth muscle cells.
European journal of pharmaceutical sciences: official journal of the European Federation for Pharmaceutical Sciences 12/2011; 45(3):344-50. · 2.61 Impact Factor
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Zumira Aparecida Carneiro,
Juliana Cristina Biazzotto de Moraes,
Fernando Postalli Rodrigues,
Renata Galvão de Lima,
Carlos Curti,
Zênis Novaes da Rocha, Michele Paulo,
Lusiane Maria Bendhack,
Antonio Claudio Tedesco,
André Luiz Barboza Formiga,
Roberto Santana da Silva
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ABSTRACT: The synthesis, structural aspects, pharmacological assays, and in vitro photoinduced cytotoxic properties of [Ru(NO)(ONO)(pc)] (pc=phthalocyanine) are described. Its biological effect on the B16F10 cell line was studied in the presence and absence of visible light irradiation. At comparable irradiation levels, [Ru(NO)(ONO)(pc)] was more effective than [Ru(pc)] at inhibiting cell growth, suggesting that occurrence of nitric oxide release following singlet oxygen production upon light irradiation may be an important mechanism by which the nitrosyl ruthenium complex exhibits enhanced biological activity in cells. Following visible light activation, the [Ru(NO)(ONO)(pc)] complex displayed increased potency in B16F10 cells upon modifications to the photoinduced dose; indeed, enhanced potency was detected when the nitrosyl ruthenium complex was encapsulated in a drug delivery system. The liposome containing the [Ru(NO)(ONO)(pc)] complex was over 25% more active than the corresponding ruthenium complex in phosphate buffer solution. The activity of the complex was directly proportional to the ruthenium amount present inside the cell, as determined by inductively coupled plasma mass spectroscopy. Flow cytometry analysis revealed that the photocytotoxic activity was mainly due to apoptosis. Furthermore, the vasorelaxation induced by [Ru(NO)(ONO)(pc)], proposed as NO carrier, was studied in rat isolated aorta. The observed vasodilation was concentration-dependent. Taken together, the present findings demonstrate that the [Ru(NO)(ONO)(pc)] complex induces vascular relaxation and could be a potent anti-tumor agent. Nitric oxide release following singlet oxygen production upon visible light irradiation on a nitrosyl ruthenium complex produces two radicals and may elicit phototoxic responses that may find useful applications in photodynamic therapy.
Journal of inorganic biochemistry 08/2011; 105(8):1035-43. · 3.25 Impact Factor
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Menopause (New York, N.Y.) 02/2010; · 3.08 Impact Factor
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ABSTRACT: In this study, we determined the protective effect of isoflavones from Glycine max on human umbilical vein endothelial cell (ECV304) damage induced by hydrogen peroxide (H2O2) and on nitric oxide (NO) production.
We studied the regulation of NO synthesis in cultured human endothelial cells by phytoestrogens contained in soy extracts in the presence or absence of ICI 182,780 or N(omega)-nitro-L-arginine methyl esther and determined the protective effect of these isoflavones on ECV304 damage induced by H2O2.
We show that soy extracts activate NO synthesis in endothelial cells and protect against cell damage.
In conclusion, soy isoflavones markedly protect ECV304 cells against H2O2 damage and promote NO synthesizing. Therefore, these isoflavones can potentially act as an NO promoter and as an antioxidant.
Menopause (New York, N.Y.) 03/2009; 16(3):539-44. · 3.08 Impact Factor
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ABSTRACT: The objective of the present study was to assess the presence of human papilloma virus (HPV) in HIV-infected women, with comparison between the Papanicolaou cytologic technique and the molecular PCR technique, as well as to determine the type of HPV, to measure cellular immunocompetence and to identify the presence of risk factors for the acquisition of HPV infection. Thirty HIV-infected women were selected. Vaginal and endocervical samples were collected from 27 of them. The smears were examined by 3 experienced cytologists to diagnose the presence of HPV by the Papanicolaou technique and the results were compared to HPV detection and typing by PCR. HPV-infected patients were interviewed in order to identify the presence of risk factors for the acquisition of the virus. Eight of the 27 patients analyzed (29%) presented HPV in endocervical samples submitted to PCR, 6 of them (75%) presented HPV involving a high risk of development of cervical cancer. For 5 of these patients, the cytologic diagnosis was not confirmed by PCR. When cellular immunocompetence was related to HPV infection, PCR revealed a diagnosis of HPV in 37.50% of the patients at intermediate risk for HPV infection and in 83.33% of the patients at high risk for HPV infection. These immunologically compromised HPV-infected patients are at higher risk of developing cervical neoplasia. We showed here that PCR is adequate for HPV detection and that, if only the Papanicolaou method is used for the follow-up of these patients, we will not provide good prevention of cervical cancer.
Brazilian Journal of Infectious Diseases 05/2007; 11(2):189-95. · 1.00 Impact Factor
