RESUMO
OBJECTIVES: To evaluate the effects of the surface modification of 316L stainless steel (SS) by low-temperature plasma nitriding on endothelial cells for stent applications. RESULTS: X-ray diffraction (XRD) confirmed the incorporation of nitrogen into the treated steel. The surface treatment significantly increased SS roughness and hydrophilic characteristics. After 4 h the cells adhered to the nitride surfaces and formed clusters. During the 24 h incubation period, cell viability on the nitrided surface was higher compared to the polished surface. Nitriding reduced late apoptosis of rabbit aorta endothelial cell (RAEC) on the SS surface. CONCLUSION: Low temperature plasma nitriding improved the biocompatible of stainless steel for use in stents.
Assuntos
Materiais Biocompatíveis/química , Fenômenos Químicos , Células Endoteliais/fisiologia , Nitrogênio/metabolismo , Gases em Plasma , Aço Inoxidável/química , Propriedades de Superfície , Adesão Celular , Sobrevivência Celular , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Stents , Difração de Raios XRESUMO
Dextrans (α-d-glucans) extracted from Leuconostoc mesenteroides, with molecular weights (MW) of 10 (D10), 40 (D40) and 147 (D147) kDa, were evaluated as antioxidant, anticoagulant and immunomodulatory drugs for the first time. None presented anticoagulant activity. As for the antioxidant and immunomodulatory tests, a specific test showed an increase in the dextran activity that was proportional to the increase in molecular weight. In a different assay, however, activity decreased or showed no correlation to the MW. As an example, the reducing power assay showed that D147 was twice as potent as other dextrans. On the other hand, all three samples showed similar activity (50%) when it came to scavenging the OH radical, whereas only the D10 sample showed sharp activity (50%) when it came to scavenging the superoxide ion. D40 was the single dextran that presented with immunomodulatory features since it stimulated the proliferation (~50%) of murine macrophages (RAW 264.7) and decreased the release of nitric oxide (~40%) by the cells, both in the absence and presence of lipopolysaccharides (LPS). In addition, D40 showed a greater scavenging activity (50%) for the hydrogen peroxide, which caused it to also be the more potent dextran when it came to inhibiting lipid peroxidation (70%). These points toward dextrans with a 40 kDa weight as being ideal for antioxidant and immunomodulatory use. However, future studies with the D40 and other similarly 40 kDa dextrans are underway to confirm this hypothesis.
Assuntos
Antioxidantes/química , Dextranos/química , Animais , Antioxidantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Dextranos/farmacologia , Leuconostoc mesenteroides/química , Peroxidação de Lipídeos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Peso Molecular , Óxido Nítrico/metabolismo , Células RAW 264.7RESUMO
Bullfrog oil is a natural product extracted from the Rana catesbeiana Shaw adipose tissue and used in folk medicine for the treatment of several diseases. The aim of this study was to evaluate the extraction process of bullfrog oil, to develop a suitable topical nanoemulsion and to evaluate its efficacy against melanoma cells. The oil samples were obtained by hot and organic solvent extraction processes and were characterized by titration techniques and gas chromatography mass spectrometry (GC-MS). The required hydrophile-lipophile balance and the pseudo-ternary phase diagram (PTPD) were assessed to determine the emulsification ability of the bullfrog oil. The anti-tumoral activity of the samples was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for normal fibroblast (3T3) and melanoma (B16F10) cell lines. Both extraction methods produced yielded around 60% and the oil was mainly composed of unsaturated compounds (around 60%). The bullfrog oil nanoemulsion obtained from PTPD presented a droplet size of about 390 nm and polydispersity = 0.05 and a zeta potential of about -25 mV. Both the bullfrog oil itself and its topical nanoemulsion did not show cytotoxicity in 3T3 linage. However, these systems showed growth inhibition in B16F10 cells. Finally, the bullfrog oil presented itself as a candidate for the development of pharmaceutical products free from cytotoxicity and effective for antineoplastic therapy.
Assuntos
Antineoplásicos/isolamento & purificação , Produtos Biológicos/uso terapêutico , Melanoma Experimental/tratamento farmacológico , Óleos/uso terapêutico , Rana catesbeiana , Células 3T3 , Animais , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Pesquisa Biomédica/tendências , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Emulsões , Células HeLa , Humanos , Camundongos , Óleos/química , Óleos/isolamento & purificação , Óleos/toxicidadeRESUMO
The limited arsenal of antifungal drugs have prompted the search for novel molecules with biological activity. This study aimed to characterize the antifungal mechanism of action of Eugenia uniflora extract and its synergistic activity with commercially available antifungal drugs on the following Candida species: C. albicans, C. tropicalis, C. glabrata, C. parapsilosis and C. dubliniensis. In silico analysis was performed to predict antifungal activity of the major compounds present in the extract. Minimal inhibitory concentrations (MICs) were determined in the presence of exogenous ergosterol and sorbitol. Yeast cells were grown in the presence of stressors. The loss of membrane integrity was assessed using propidium iodide staining (fluorescence emission). Synergism between the extract and antifungal compounds (in addition to time kill-curves) was determined. Molecular docking revealed possible interactions between myricitrin and acid gallic and enzymes involved in ergosterol and cell wall biosynthesis. Candida cells grown in the presence of the extract with addition of exogenous ergosterol and sorbitol showed 2 to 8-fold increased MICs. Strains treated with the extract revealed greater loss of membrane integrity when compared to their Fluconazole counterparts, but this effect was less pronounced than the membrane damage caused by Amphotericin B. The extract also made the strains more susceptible to Congo red and Calcofluor white. A synergistic action of the extract with Fluconazole and Micafungin was observed. The E. uniflora extract may be a viable option for the treatment of Candida infections.
Assuntos
Antifúngicos , Candida , Sinergismo Farmacológico , Eugenia , Testes de Sensibilidade Microbiana , Extratos Vegetais , Eugenia/química , Antifúngicos/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Candida/efeitos dos fármacos , Ergosterol , Simulação de Acoplamento Molecular , Fluconazol/farmacologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismoRESUMO
Copaiba oil has been largely used due to its therapeutic properties. Nanocapsules were revealed to be a great nanosystem to carry natural oils due to their ability to improve the bioaccessibility and the bioavailability of lipophilic compounds. The aim of this study was to produce and characterize copaiba oil nanocapsules (CopNc) and to evaluate their hemocompatibility, cytotoxicity, and genotoxicity. Copaiba oil was chemically characterized by GC-MS and FTIR. CopNc was produced using the nanoprecipitation method. The physicochemical stability, toxicity, and biocompatibility of the systems, in vitro, were then evaluated. Β-bisabolene, cis-α-bergamotene, caryophyllene, and caryophyllene oxide were identified as the major copaiba oil components. CopNc showed a particle size of 215 ± 10 nm, a polydispersity index of 0.15 ± 0.01, and a zeta potential of -18 ± 1. These parameters remained unchanged over 30 days at 25 ± 2 °C. The encapsulation efficiency of CopNc was 54 ± 2%. CopNc neither induced hemolysis in erythrocytes, nor cytotoxic and genotoxic in lung cells at the range of concentrations from 50 to 200 µg·mL-1. In conclusion, CopNc showed suitable stability and physicochemical properties. Moreover, this formulation presented a remarkable safety profile on lung cells. These results may pave the way to further use CopNc for the development of phytotherapeutic medicine intended for pulmonary delivery of copaiba oil.
RESUMO
Endothelial cells (ECs) are a source of physiologically important molecules that are synthesized and released to the blood and/or to the subendothelial extracellular matrix such as a heparan sulfate proteoglycan (HSPG) with antithrombotic properties. Previously, we have shown that heparin stimulates the synthesis and modifies the sulfation pattern of this HSPG. Here the molecular mechanisms involved in the up-regulation of HSPG synthesis by heparin in endothelial cells were decoded. The cells were stimulated with heparin and the expression of HSPG and intracellular pathways were evaluated by a combination of methods involving confocal microscopy, flow cytometry, Western blotting analyses, and [(35) S]-sulfate metabolically labeling of the cells. We observed that the up-regulation of HSPG synthesis evoked by heparin is dependent on the interaction of heparin with integrin since RGD peptide abolishes the effect. The activation of integrin leads to tyrosine-phosphorylation of focal adhesion-associated proteins such as FAK, Src, and paxillin. In addition, heparin induces ERK1/2 phosphorylation and inhibitors of Ras and MEK decreased heparin-dependent HSPG synthesis. Moreover, heparin also induced intracellular Ca(2+) release, PLCγ1 (phospholipase Cγ1) and CaMKII (calcium calmodulin kinase II) activation, as well as an increase in nitric oxide (NO) production. Finally, an intracellular Ca(2+) chelator, Ca(2+) signaling inhibitors, and an endothelial NO synthase inhibitor were all able to abolish the effect in heparan sulfate synthesis. In conclusion, the heparin-induced up-regulation of HSPG expression is associated with the phosphorylation of focal adhesion proteins and Ras/Raf/MEK/ERK MAP and Ca(2+) /NO pathways.
Assuntos
Células Endoteliais/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Heparina/metabolismo , Heparitina Sulfato/metabolismo , Integrinas/metabolismo , Animais , Anticoagulantes/metabolismo , Anticoagulantes/farmacologia , Western Blotting , Cálcio/metabolismo , Sinalização do Cálcio , Adesão Celular , Fibronectinas/química , Fibronectinas/metabolismo , Citometria de Fluxo , Heparina/farmacologia , Heparitina Sulfato/genética , Microscopia Confocal , Óxido Nítrico , Fosforilação , Ligação Proteica , Coelhos , Regulação para CimaRESUMO
The prophylactic and therapeutic arsenal against malaria is quite restricted and all the antimalarials currently in use have limitations. Thus, there is a need to investigate medicinal plants in the search for phytochemicals which can be developed into drugs. In our investigation, essential oils (EOs) were obtained from Vanillosmopsis arborea (Gardner) Baker, Lippia sidoides Cham. and Croton zehntneri Pax & K. Hoffm., aromatic plants abundant in northeastern Brazil, which are found in the caatinga region and are used in traditional medicine. The chemical composition of these EOs was characterized by GC-MS, and monoterpenes and sesquiterpenes were well represented. We assessed the in vitro activity of these EOs and also individual EO chemical components against the human malaria parasite Plasmodium falciparum (K1 strain) and the in vivo activity of EOs in mice infected with Plasmodium berghei. The acute toxicity of these oils was assessed in healthy mice and in vitro cytotoxicity was determined at different concentrations against HeLa cells and mice macrophages. The EO of V. Arborea was partially active only when using the subcutaneous route (inhibited from 33 up to 47 %). In relation to the EOs, L. sidoides and C. zehntneri were active only by the oral route (per gavage) and partially inhibited the growth of P. berghei from 43 up to 55 % and showed good activity against P. falciparum in vitro (IC (50) = 7.00, 10.50, and 15.20 µg/mL, respectively). Individual EO constituents α-bisabolol, estragole, and thymol also exhibited good activity against P. falciparum (IC (50) = 5.00, 30.70, and 4.50 µg/mL, respectively). This is the first study showing evidence for the antimalarial activity of these species from northeastern Brazil and the low toxicity of their EOs.
Assuntos
Antimaláricos/administração & dosagem , Asteraceae/química , Croton/química , Lippia/química , Malária Falciparum/tratamento farmacológico , Óleos Voláteis/administração & dosagem , Fitoterapia , Administração Oral , Derivados de Alilbenzenos , Animais , Anisóis/administração & dosagem , Brasil , Células HeLa/efeitos dos fármacos , Humanos , Infusões Subcutâneas , Camundongos , Sesquiterpenos Monocíclicos , Folhas de Planta/química , Preparações de Plantas/administração & dosagem , Caules de Planta/química , Plantas Medicinais/química , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Sesquiterpenos/administração & dosagem , Timol/administração & dosagemRESUMO
BACKGROUND: Although bullfrog oil (BFO) exerts anti-inflammatory effects, it has undesirable properties limiting its use. METHODOLOGY: BFO nanocapsules (BFONc) were produced through nanoprecipitation, and their physicochemical and morphological properties were characterized. To evaluate the biocompatibility of the formulation, a mitochondrial activity evaluation assay was conducted, and cell uptake was assessed. The in vitro anti-inflammatory activity was evaluated by measuring reactive oxygen species (ROS), nitric oxide (NO), type-6 interleukin (IL-6), and tumor necrosis factor (TNF) levels. The in vivo anti-inflammatory effect was assessed by quantifying myeloperoxidase (MPO) levels using the carrageenan-induced paw edema model. RESULTS: BFONc showed a particle size of 233 ± 22 nm, a polydispersity index of 0.17 ± 0.03, and a zeta potential of -34 ± 2.6mV. BFONc revealed remarkable biocompatibility and did not induce changes in cell morphology. Furthermore, BFONc decreased ROS levels by 81 ± 4%; however, NO level increased by 72 ± 18%. TNF and IL-6 levels were reduced by approximately 10% and 90%, respectively. Significant in vivo anti-inflammatory activity was observed compared to dexamethasone. MPO levels were reduced up to 2 MPOs/mg. CONCLUSION: Taken together, the results pointed out the remarkable biocompatibility and anti-inflammatory effects of BFONc.
Assuntos
Nanocápsulas , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Carragenina , Edema/tratamento farmacológico , Nanocápsulas/uso terapêutico , Extratos Vegetais/uso terapêutico , Rana catesbeiana , Fator de Necrose Tumoral alfa/uso terapêuticoRESUMO
Thrombin triggers cellular responses that are crucial for development and progression of cancer, such as proliferation, migration, oncogene expression and angiogenesis. Thus, biomolecules capable of inhibiting this protease have become targets in cancer research. The present work describes the in vitro antitumor properties of a chondroitin sulfate with anti-thrombin activity, isolated from the Litopenaeus vannamei shrimp (sCS). Although the compound was unable to induce cytotoxicity or cell death and/or cell cycle changes after 24 h incubation, it showed a long-term antiproliferative effect, reducing the tumor colony formation of melanoma cells by 75% at 100 µg/mL concentration and inhibiting the anchorage-independent colony formation. sCS reduced 66% of melanoma cell migration in the wound healing assay and 70% in the transwell assay. The compound also decreased melanin and TNF-α content of melanoma cells by 52% and 75% respectively. Anti-angiogenic experiments showed that sCS promoted 100% reduction of tubular structure formation at 100 µg/mL. These results are in accordance with the sCS-mediated in vitro expression of genes related to melanoma development (Cx-43, MAPK, RhoA, PAFR, NFKB1 and VEGFA). These findings bring a new insight to CS molecules in cancer biology that can contribute to ongoing studies for new approaches in designing anti-tumor therapy.
Assuntos
Inibidores da Angiogênese , Antineoplásicos , Sulfatos de Condroitina , Melanoma Experimental/tratamento farmacológico , Penaeidae/química , Inibidores da Angiogênese/química , Inibidores da Angiogênese/isolamento & purificação , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sulfatos de Condroitina/química , Sulfatos de Condroitina/isolamento & purificação , Sulfatos de Condroitina/farmacologia , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , CoelhosRESUMO
We evaluated the effects of titanium plasma nitriding and oxidation on live endothelial cell viscoelasticity. For this, mechanically polished titanium surfaces and two surfaces treated by planar cathode discharge in nitriding (36N2 and 24H2) and oxidant (36O2 and 24H2). Surfaces were characterized regarding wettability, roughness and chemical composition. Rabbit aortic endothelial cells (RAECs) were cultured on the titanium surfaces. Cell morphology, viability and viscoelasticity were evaluated by scanning electron microscopy (SEM), methyl thiazolyl tetrazolium (MTT) assay and atomic force microscopy (AFM), respectively. Grazing Incidence X-ray Diffraction confirmed the presence of TiN0,26 on the surface (grazing angle theta 1°) of the nitrided samples, decreasing with depth. On the oxidized surface had the formation of TiO3 on the material surface (Theta 1°) and in the deeper layers was noted, with a marked presence of Ti (Theta 3°). Both plasma treatments increased surface roughness and they are hydrophilic (angle <90°). However, oxidation led to a more hydrophilic titanium surface (66.59° ± 3.65 vs. 76.88° ± 2.68; p = 0.001) due to titanium oxide films in their stoichiometric varieties (Ti3O, TiO2, Ti6O), especially Ti3O. Despite focal adhesion on the surfaces, viability was different after 24 h, as cell viability on the oxidized surface was higher than on the nitrided surface (9.1 × 103 vs. 4.5 × 103cells; p < 0.05). This can be explained by analyzing the viscoelastic property of the cellular cytoskeleton (nuclear and peripheral) by AFM. Surface oxidation significantly increased RAECs viscoelasticity at cell periphery, in comparison to the nucleus (2.36 ± 0.3 vs. 1.5 ± 0.4; p < 0.05), and to the RAECs periphery in contact with nitrided surfaces (1.36 ± 0.7; p < 0.05) and polished surfaces (1.55 ± 0.6; p < 0.05). Taken together, our results have shown that titanium plasma treatment directly increased cell viscoelasticity via surface oxidation, and this mechanobiological property subsequently increased biocompatibility.
Assuntos
Materiais Biocompatíveis/química , Nitrogênio/química , Oxigênio/química , Gases em Plasma/química , Titânio/química , Animais , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Citoesqueleto/química , Módulo de Elasticidade , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Oxirredução , Coelhos , Propriedades de SuperfícieRESUMO
Bullfrog oil (BFO) is a natural product from the adipose tissue of the amphibian Rana catesbeiana Shaw, a bio-product rich in polyunsaturated fatty acids, which claims anti-inflammatory activity. The objective of this work was to evaluate the cytotoxicity and the anti-inflammatory activity of BFO using in vivo and in vitro assays. Thus, the in vitro cytotoxicity was assessed by the MTT assay. Additionally, the in vivo anti-inflammatory activity was performed by the carrageenan-induced paw edema model in Wistar rats, followed by histological analysis. Moreover, the BFO effect on inflammatory pathways was investigated by in vitro evaluation of the nitric oxide (NO) synthesis, and type-6 interleukin (IL-6) and tumor-necrosis-factor (TNF) levels. In vivo experiments showed that BFO administered by intragastric route produced a significant anti-inflammatory effect, which was as substantial as indomethacin, the positive control. Histopathological analysis confirmed these results, showing the absence of the edema and minimal signs of inflammation in the paws of rats treated with BFO. The MTT results showed that BFO at all tested concentrations had no toxic effect against a macrophage cell line, not affecting the cell viability. In addition, after 48 hours of treatment, the BFO itself and its blend with Cetiol®-V (1:1v/v) at 200 µg.mL-1 were able to reduce the NO synthesis, and the IL-6 and TNF levels up to 35 ± 2%, 40 ± 6%, and 12 ± 3%, respectively. Therefore, these results provide unprecedented scientific evidence of the anti-inflammatory effect of BFO, suggesting its potential as a new candidate for the development of pharmaceutical products with anti-inflammatory activity.
Assuntos
Carragenina , Edema/induzido quimicamente , Edema/metabolismo , Mediadores da Inflamação/metabolismo , Rana catesbeiana , Extratos de Tecidos/farmacologia , Animais , Anti-Inflamatórios , Técnicas In Vitro , Masculino , Ratos Wistar , Extratos de Tecidos/efeitos adversosRESUMO
Prosopis juliflora is an invasive plant distributed throughout the world and presents metabolites of interest for cosmetology. The aim of this work was to develop a new polysaccharide-based ingredient from P. juliflora and analyze its application in a solid core formulation that upon contact with water instantly forms a gel to improve moisturizing and anti-aging skin properties. Purified extracts by gel chromatography were characterized by NMR and LC-DAD-MS-MS. The in vitro and in vivo safety, antioxidant activity, formulation development and clinical evaluation were performed. The extract was characterized as containing an α-glucan and phenolics. It was non-cytotoxic, non-phototoxic and no skin reactions were observed in vivo. Antioxidant activity were present through different mechanisms. Clinical evaluation reinforced the potential of P. juliflora in skin hydration and microrelief improvement. This innovative form proved to be a prototype of a new product and the first study of an α-glucan as a cosmetic ingredient.
Assuntos
Antioxidantes/farmacologia , Géis/farmacologia , Extratos Vegetais/farmacologia , Prosopis/química , Creme para a Pele/farmacologia , Adulto , Idoso , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/toxicidade , Células 3T3 BALB , Feminino , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Flavonoides/toxicidade , Frutas/química , Géis/química , Géis/isolamento & purificação , Géis/toxicidade , Glucanos/química , Glucanos/isolamento & purificação , Glucanos/farmacologia , Glucanos/toxicidade , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Fenóis/toxicidade , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Pele/efeitos dos fármacos , Creme para a Pele/química , Adulto JovemRESUMO
Alpha5beta1 integrin from both wild-type CHO cells (CHO-K1) and deficient in proteoglycan biosynthesis (CHO-745) is post-translationally modified by glycosaminoglycan chains. We demonstrated this using [35S]sulfate metabolic labeling of the cells, enzymatic degradation, immunoprecipitation reaction with monoclonal antibody, fluorescence microscopy, and flow cytometry. The alpha5beta1 integrin heterodimer is a hybrid proteoglycan containing both chondroitin and heparan sulfate chains. Xyloside inhibition of sulfate incorporation into alpha5beta1 integrin also supports that integrin is a proteoglycan. Also, cells grown with xyloside adhered on fibronectin with no alteration in alpha5beta1 integrin expression. However, haptotactic motility on fibronectin declined in cells grown with xyloside or chlorate as compared with controls. Thus, alpha5beta1 integrin is a proteoglycan and the glycosaminoglycan chains of the integrin influence cell motility on fibronectin. Similar glycosylation of alpha5beta1 integrin was observed in other normal and malignant cells, suggesting that this modification is conserved and important in the function of this integrin. Therefore, these glycosaminoglycan chains of alpha5beta1 integrin are involved in cellular migration on fibronectin.
Assuntos
Movimento Celular/fisiologia , Fibronectinas/fisiologia , Glicosaminoglicanos/química , Integrina alfa5beta1/química , Animais , Células CHO , Cricetinae , Cricetulus , Eletroforese em Gel de Ágar , Citometria de Fluxo , Imunoprecipitação , Microscopia de FluorescênciaRESUMO
In vitro, heparin and antithrombotic drugs specifically stimulate the synthesis of an antithrombotic heparan sulfate proteoglycan (HSPG) produced by endothelial cells. The putative heparin binding site(s) that may be related to this phenomenon were investigated. In the preceding article, using various heparin probes, it was shown that the heparin does not bind to the endothelial cell surface, but only to the extracellular matrix. The present study demonstrated that, when the cells were exposed to heparin at 37 degrees C, the heparin was internalized and with time was localized in lysosomes. However, endocytosis of heparin was not required for the stimulation of HSPG synthesis. The requirement for heparin degradation in the stimulus of HSPG synthesis was also investigated. When the cells were incubated with chloroquine, a lysosomotropic amine that raises the lysosomal pH thus inhibiting enzymatic degradation of internalized compounds, stimulation of HSPG synthesis was still observed. These combined results indicate that neither internalization nor degradation of heparin is required for stimulation of HSPG synthesis, and suggests that its binding to the extracellular matrix could be responsible for this effect.
Assuntos
Endocitose , Células Endoteliais/efeitos dos fármacos , Fibrinolíticos/farmacologia , Heparina/análogos & derivados , Heparina/farmacologia , Lisossomos/efeitos dos fármacos , Proteoglicanas/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Cloroquina/farmacologia , Células Endoteliais/enzimologia , Células Endoteliais/ultraestrutura , Matriz Extracelular/metabolismo , Fibrinolíticos/metabolismo , Heparina/metabolismo , Concentração de Íons de Hidrogênio , Lisossomos/enzimologia , Lisossomos/ultraestrutura , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Microscopia de Vídeo , Ligação Proteica , Coelhos , Fatores de TempoRESUMO
Exposure of endothelial cells to heparin and other antithrombotic drugs specifically stimulates the synthesis of an antithrombotic heparan sulfate (HS). In the present work, biotinylated heparin (BiotHep) was used to characterize the binding site(s) of heparin responsible for the stimulus in HS synthesis on endothelial cells. No differences were observed between biotinylated and non-biotinylated heparin in their ability to increase the synthesis of HS. In kinetic studies the BiotHep showed fast, saturable and specific binding with an apparent K(D) of 83 nM to adherent cells and 44 nM to the extracellular matrix (ECM) in the absence of cells. By confocal and electron microscopy, BiotHep bound only to the ECM, co-localizing with fibronectin. The same pattern of binding to the ECM was observed using heparin conjugated with FITC or Alexa Fluor 488 in the presence or absence of fetal calf serum. However, after degradation of HS, heparin binds to the cell surface, indicating that endogenous HS possibly occupied the heparin binding sites. Analyses by flow cytometry and confocal microscopy of cells with non-associated ECM, showed labeling of the cell surface using syndecan-4 monoclonal antibody as well as wheat germ agglutinin, but no binding of heparin. Furthermore, the stimulation in HS synthesis is not elicited by heparin in the absence of ECM. These results indicate that the stimulus for the synthesis of HS does not require binding of the heparin to the cell surface, and the signaling may be mediated through the ECM.
Assuntos
Células Endoteliais/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Fibrinolíticos/farmacologia , Heparina/análogos & derivados , Heparina/farmacologia , Proteoglicanas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Sítios de Ligação , Biotinilação , Células COS , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Chlorocebus aethiops , Células Endoteliais/metabolismo , Células Endoteliais/ultraestrutura , Matriz Extracelular/metabolismo , Matriz Extracelular/ultraestrutura , Fibrinolíticos/metabolismo , Citometria de Fluxo , Fluoresceína-5-Isotiocianato , Corantes Fluorescentes , Heparina/metabolismo , Humanos , Hidrazinas , Cinética , Ligantes , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Ligação Proteica , Coelhos , Regulação para CimaRESUMO
The green algae of the genus Codium have recently been demonstrated to be an important source of sulfated galactans from the marine environment. Here, a sulfated galactan was isolated from the species Codium isthmocladum and its structure was studied by a combination of chemical analyses and NMR spectroscopy. Two fractions (SG 1, approximately 14 kDa, and SG 2, approximately 20 kDa) were derived from this highly polydisperse and heterogeneous polysaccharide. Both exhibited similar structures in (1)H 1D NMR spectra. The structural features of SG 2 and its desulfated derivative were analyzed by COSY, TOCSY, DEPT-HSQC, HSQC, and HMBC. This sulfated galactan is composed preponderantly of 4-sulfated, 3-linked beta-D-galactopyranosyl units. In minor amounts, it is sulfated and glycosylated at C-6. Pyruvate groups are also found, forming five-membered cyclic ketals as 3,4-O-(1'carboxy)-ethylidene-beta-D-galactose residues. A comparison of sulfated galactans from different marine taxonomic groups revealed similar backbones of 3-beta-D-Galp-1.
Assuntos
Clorófitas/química , Galactanos/química , Sulfatos/química , Configuração de Carboidratos , Eletroforese em Gel de Ágar/métodos , Eletroforese em Gel de Poliacrilamida/métodos , Galactanos/isolamento & purificação , Espectroscopia de Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/normas , Padrões de Referência , Especificidade da EspécieRESUMO
Scorpion venom is a rich source of biologically active components and various peptides with high-potential therapeutic use that have been characterized for their antimicrobial and antiproliferative activities. Stigmurin is a peptide identified from the Tityus stigmurus venom gland with high antibacterial and antiproliferative activities and low toxicity. Amino acid substitutions in peptides without a disulfide bridge sequence have been made with the aim of reducing their toxicity and increasing their biological activities. The purpose of this study was to evaluate the structural conformation and structural stability, as well as antimicrobial, antiproliferative, and hemolytic activities of two peptide analogs to Stigmurin, denominated StigA6 and StigA16. In silico analysis revealed the α-helix structure for both analog peptides, which was confirmed by circular dichroism. Data showed that the net charge and hydrophobic moment of the analog peptides were higher than those for Stigmurin, which can explain the increase in antimicrobial activity presented by them. Both analog peptides exhibited activity on cancerous cells similar to the native peptide; however, they were less toxic when tested on the normal cell line. These results reveal a potential biotechnological application of the analog peptides StigA6 and StigA16 as prototypes to new therapeutic agents.
Assuntos
Anti-Infecciosos/farmacologia , Peptídeos/farmacologia , Venenos de Escorpião/farmacologia , Células 3T3 , Sequência de Aminoácidos , Animais , Anti-Infecciosos/química , Bactérias/efeitos dos fármacos , Candida/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Células HeLa , Humanos , Camundongos , Simulação de Dinâmica Molecular , Peptídeos/química , Estrutura Secundária de Proteína , Venenos de Escorpião/química , Trypanosoma cruzi/efeitos dos fármacosRESUMO
The Geastrum saccatum a mushroom, native to Brazil, is produced under natural conditions in the unexplored reserve of Mata da Estrela-RN. This species has curative properties for eye infections and diseases such as asthma. The tissues of this mushroom contain carbohydrates, proteins, lipids, moisture and ashes in amounts of 42.3%, 37.05%, 9.01, 1.4% and 10.2%, respectively. An extract from this mushroom was characterized by chemical analyses and (13)C and (1)H NMR spectroscopy. It contains high amount of glucose and traces of galactose. The signal appearing at 103.5 ppm was assigned to C1 of beta-glucose. The signals observed between 20 and 40 ppm suggest the presence of a glucan-protein compound. This glucan inhibited the lipid peroxidation at the dose of 0.27 mg/mL (59.1%) and it can protect cells against oxidative stress by scavenging of the hydroxyl (77%) and superoxide (88.4%) radicals at 0.27 mg/mL. The glucan (30 mg/kg) reduces the polymorphonuclear cell migration (57.6%). The ear edema induced by croton oil was inhibited by glucan (60.4% at 10 mg/kg) and by its association with diclofenac (5 mg/kg) (89.2%) or L-NAME (60 mg/kg) (86.23%). Histological analyses of the ear edema induced by croton oil in the presence of glucan (10, 30 or 50 mg/kg) showed a reduced degree of the polymorphonuclear cell migration. We concluded that the glucan has antioxidant, and antiinflammatory properties as well as its antiinflammatory effect are mediated by inhibition of both nitric oxide synthase (NOS) and cyclooxygenase (COX).
Assuntos
Agaricales , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Produtos Biológicos/farmacologia , Citotoxinas/farmacologia , beta-Glucanas/farmacologia , Animais , Edema/tratamento farmacológico , Proteínas Fúngicas/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pleurisia/tratamento farmacológico , Ratos , Ratos WistarRESUMO
The most widely used technique for the production of DNA aptamers/oligonucleotides is chemical synthesis. Despite its effectiveness, this technique cannot be performed "in house", making the user fully dependent on a supplier. In this work, we present a simplified method by which it is possible to enzymatically produce DNA aptamers "in house". This new method uses the rolling circle replication followed by a unique cleavage step using the SchI endonuclease. Potentially, any oligonucleotide can be produced by the enzymatic method proposed in this study. To illustrate, we present the production of three variations of the 31-TBA aptamer, a single stranded DNA which has anticoagulant action.
Assuntos
Aptâmeros de Nucleotídeos/biossíntese , DNA de Cadeia Simples/biossíntese , Técnicas de Amplificação de Ácido Nucleico , Oligodesoxirribonucleotídeos/biossíntese , Anticoagulantes/síntese química , Anticoagulantes/metabolismo , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Enzimas de Restrição do DNA/metabolismo , DNA de Cadeia Simples/genética , Quadruplex G , Humanos , Oligodesoxirribonucleotídeos/genéticaRESUMO
Objectives: Evaluation of phenolic compounds and antioxidant activities of aqueous extracts of C. longa, P. nigrum and C. cyminum. In addition to proposing a quantum-mechanical model to evaluate the antioxidant activity. Methods: The aqueous extracts were prepared using roots of the Curcuma longa L., seeds of the Piper nigrum L. and seeds of Cuminum cyminum. The extracts were subjected to tests to detect and quantify phenolic compounds and to assess their antioxidant capacity by different methods. Furthermore, to investigate the electronic nature of the antioxidant activity of the main compounds present in these extracts, frontier molecular orbitals (FMOs) were obtained by the DFT/B3LYP/6-31G(d,p) level of theory. Results: After statistical analysis of the results, a greater number of phenolic compounds and better antioxidant activity was identified in the aqueous extracts of cumin (C. cyminum) in all three assays performed, when compared to the other extracts tested. The theoretical model based on the Pietro method is in agreement with the experimental results. Conclusion: This study has an innovative proposal with the trivial antioxidant activity combined with theoretical quantum-mechanical calculations that can serve to reduce costs and time and to predict the antioxidant activity of subsequent studies.
Objetivos: avaliar os compostos fenólicos e atividades antioxidantes dos extratos aquosos de C. longa, P. nigrum e C. cyminum bem como propor um modelo quanto-mecânico para avaliar a atividade antioxidante. Métodos: os extratos aquosos foram preparados por meio da utilização de raízes de Curcuma longa L., sementes de Piper nigrum L. e sementes de Cuminum cyminum. Os extratos foram submetidos a ensaios para detectar e quantificar compostos fenólicos e atividade antioxidante por diferentes métodos. Além disso, com objetivo de investigar a natureza eletrônica da atividade antioxidante dos principais compostos presentes nesses extratos, orbitais moleculares de fronteira (OMFs) foram obtidos pelo nível de teoria DFT/B3LYP/6-31G(d,p). Resultados: após as análises estatísticas dos resultados, a maior quantidade de compostos fenólicos com maior atividade antioxidante foi identificada no extrato aquoso do cominho (C. cyminum) em todos os ensaios realizados, quando comparados com os outros extratos testados. O modelo teórico baseado no método de Pietro está concordante com os resultados experimentais. Conclusão: este estudo possui uma proposta inovadora com a atividade antioxidante trivial combinada com cálculos quanto-mecânicos que podem servir para reduzir custos e tempo para predizer a atividade antioxidante de estudos futuros.