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1.
Braz. J. Pharm. Sci. (Online) ; 60: e23484, 2024. graf
Artigo em Inglês | LILACS | ID: biblio-1533984

RESUMO

Abstract We investigated the vasodilatory effects of Hymenaea rubriflora Ducke stem bark extract (HRHAc). Vascular reactivity of the aortic rings of Wistar rats was tested by in vitro cumulative doses (0.1 - 729 µg/mL). Rats (n=5) were treated with 25 (G25), 50 (G50) and 100 (G100) mg/ kg of HR-HAc or saline (control group - CG) for four weeks. An in vitro assay resulted in dose-dependent relaxation of the aortic rings with functional endothelium, which was inhibited in the presence of L-NAME. Rings of the treated animals increased acetylcholine relaxing potency at all doses, with a greater effect on G50 (pD2 = 7.8±0.1, Emax = 95.6±1.1) and a decreased contractile potency to phenylephrine in G25 (pD2 = 6.9±0.06, Emax = 61.5±6.0%) and G50 (pD2= 6.6±0.06, Emax = 71.0±8.5%) when compared to the CG in the presence and absence of endothelium (pD2= 6.4± 0.1, 6.4±0.1 and 6.9±0.1, respectively). Cumulative doses of nitroprusside resulted in increased relaxing potency in all treated groups and maintained Emax at 100%. It is concluded that HR-HAc has vasorelaxant capacity and inhibitory vascular contraction activity applied either directly to aortic rings or after treatment with in vivo supplementation, which places this extract as a potential nutraceutical or pharmacological agent for treating diseases associated with vascular dysfunction.


Assuntos
Animais , Masculino , Ratos , Extratos Vegetais/análise , Acetilcolina/agonistas , Assistência ao Convalescente/ética , Hymenaea/efeitos adversos , Técnicas In Vitro/métodos , Microscopia Eletrônica de Transmissão e Varredura/instrumentação , Suplementos Nutricionais/classificação
2.
Dalton Trans ; 50(45): 16819-16828, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34775504

RESUMO

Environmentally friendly synthesis of Cu(In,Ga)Se2 (CIGS) nanoparticles (NPs) is pivotal for producing sustainable photocatalytic compounds to be applied in the remediation of contaminants of emerging concern from water. To this end, we herein report an aqueous synthesis of CIGS NPs, followed by annealing, to give access to phase-pure CIGS crystals with chalcopyrite structure and no signs of secondary phases. Morphological and compositional characterization revealed NPs with an average size of 10-35 nm and uniform distribution of Cu, In, Ga, and Se elements. In addition, the first aqueous large-scale synthesis of CIGS NPs is developed by up-scaling the synthesis procedure, resulting in 5 g of highly crystalline nanoparticles exhibiting an ideal optical band gap of 1.14 eV. The as-synthesized NPs proved the ability to remove 71 and 83% of a contaminant of emerging concern, ciprofloxacin (CIP), under ultraviolet (UV) and visible (Vis) radiations, respectively.


Assuntos
Ciprofloxacina/química , Cobre/química , Gálio/química , Índio/química , Nanopartículas Metálicas/química , Selênio/química , Catálise , Microscopia Eletrônica de Transmissão e Varredura , Processos Fotoquímicos , Termogravimetria , Água/química , Difração de Raios X
3.
Rev. cuba. med. trop ; 73(1): e573, tab, graf
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1280324

RESUMO

. Introducción: El dengue es la enfermedad viral transmitida por mosquitos de más rápida propagación en el mundo. A pesar de la alta incidencia de la enfermedad no existe tratamiento antiviral efectivo ni vacuna aprobada para su uso contra esta infección. La planta Ageratina havanensis ha sido ampliamente utilizada por nuestra cultura popular y en otros países debido a sus diversas propiedades biológicas. Objetivo: Evaluar la actividad antiviral de cuatro extractos provenientes de Ageratina havanensis y dos flavonoides aislados de dicha planta frente al virus dengue 2. Métodos: La pesquisa primaria de actividad antiviral de cada extracto y flavonoide se realizó mediante el ensayo de detección de la productividad vírica, y se evaluó la acción virucida de los extractos etanólico de tallo y butanólico de hoja. Resultados: Todos los extractos inhibieron la replicación viral al evidenciarse disminución del número de placas de lisis, sin embargo, no se evidenció disminución del título infectivo viral en el ensayo virucida. El tratamiento con la sakuranetina mostró valores de inhibición de la productividad viral entre 61-91 por ciento, y para la 7-metoxiaromadendrina se registraron valores de reducción viral entre 64-86 por ciento. Conclusiones: Los extractos y flavonoides aislados de Ageratina havanensis mostraron acción antiviral. Los extractos etanólico de tallo y butanólico de hojas no poseen acción virucida sobre la cepa viral empleada. El presente trabajo constituye el primer informe respecto a la evaluación de extractos y compuestos aislados de A. havanensis frente al virus dengue(AU)


Introduction: Dengue is the fastest spreading mosquito-borne viral disease worldwide. Despite its high incidence, no effective antiviral treatment or vaccine has been approved for use against this infection. The plant Ageratina havanensis has been widely used in our folk culture and in other countries due to its various biological properties. Objective: Evaluate the antiviral activity of four extracts from Ageratina havanensis and two flavonoids isolated from that plant against the dengue 2 virus. Methods: Primary screening of the antiviral activity of each extract and flavonoid was conducted by viral productivity detection assay, and an evaluation was carried out of the virucidal action of the stem ethanolic extract and the leaf butanolic extract. Results: All the extracts inhibited viral replication by a reduction in the number of lysis plates. However, no evidence was found of a reduced viral infective titer in the virucidal assay. Treatment with sakuranetin achieved viral productivity inhibition values of 61 percent-91 percent, whereas 7-methoxyaromadendrin obtained viral reduction values of 64 percent-86 percent Conclusions: The extracts and flavonoids isolated from Ageratina havanensis displayed antiviral activity. The stem ethanolic extract and the leaf butanolic extract do not have a virucidal action against the viral strain used. The paper is the first report about the effect of extracts and compounds isolated from A. havanensis against the dengue virus(AU)


Assuntos
Humanos , Microscopia Eletrônica de Transmissão e Varredura , Ageratina , Dengue , Vírus da Dengue
4.
Int J Mol Sci ; 21(24)2020 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-33322169

RESUMO

Crystal-bearing cells or idioblasts, which deposit calcium oxalate, are located in various tissues and organs of many plant species. The functional significance of their formation is currently unclear. Idioblasts in the leaf parenchyma and the development of crystal-bearing cells in the anther tissues of transgenic tomato plants (Solanum lycopersicon L.), expressing the heterologous FeSOD gene and which showed a decrease in fertility, were studied by transmission and scanning electron microscopy. The amount of calcium oxalate crystals was found to increase significantly in the transgenic plants compared to the wild type (WT) ones in idioblasts and crystal-bearing cells of the upper part of the anther. At the same time, changes in the size and shape of the crystals and their location in anther organs were noted. It seems that the interruption in the break of the anther stomium in transgenic plants was associated with the formation and cell death regulation of a specialized group of crystal-bearing cells. This disturbance caused an increase in the pool of these cells and their localization in the upper part of the anther, where rupture is initiated. Perturbations were also noted in the lower part of the anther in transgenic plants, where the amount of calcium oxalate crystals in crystal-bearing cells was reduced that was accompanied by disturbances in the morphology of pollen grains. Thus, the induction of the formation of crystal-bearing cells and calcium oxalate crystals can have multidirectional effects, contributing to the regulation of oxalate metabolism in the generative and vegetative organs and preventing fertility when the ROS balance changes, in particular, during oxidative stresses accompanying most abiotic and biotic environmental factors.


Assuntos
Oxalato de Cálcio/metabolismo , Flores/metabolismo , Frutas/metabolismo , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Pólen/metabolismo , Solanum lycopersicum/metabolismo , Oxalato de Cálcio/efeitos adversos , Fertilidade/genética , Fertilidade/fisiologia , Flores/citologia , Flores/genética , Flores/ultraestrutura , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Solanum lycopersicum/citologia , Microscopia Eletrônica de Transmissão e Varredura , Folhas de Planta/ultraestrutura , Pólen/citologia , Pólen/genética , Pólen/ultraestrutura , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
5.
Food Chem ; 321: 126737, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32278275

RESUMO

Pyrocatechol violet impregnated magnetic graphene oxide hybrid material (PV-MGO) was prepared as magnetic solid phase microextraction for separation and preconcentration of copper before its determination by flame atomic absorption spectrometry. PV-MGO hybrid material was characterized using field emission scanning electron microscope (FE-SEM, SEM-Mapping), scanning transmission electron microscopy (STEM), energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Raman spectroscopy. Effects of various parameters such as pH, eluent type, vortex time, amount of magnetic adsorbent were investigated. Under the optimized conditions the MSPE-FAAS procedure presents limit of detection (LOD) of 4.0 µg L-1, limit of quantification (LOQ) of 13.3 µg L-1, preconcentration factor of 20 and relative standard deviation (RSD) 4.93%. The accuracy of the method was confirmed by the analysis of the certified reference materials (NCS ZC73032 Celery, CRM025-050 metals on soil, TMDA-64.2 fortified water) and addition-recovery tests. The present method was successfully applied to water, black tea and diet supplements.


Assuntos
Benzenossulfonatos/química , Cobre/análise , Suplementos Nutricionais/análise , Microextração em Fase Sólida/métodos , Chá , Grafite/química , Limite de Detecção , Magnetismo , Microscopia Eletrônica de Transmissão e Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Água/análise , Poluentes Químicos da Água/análise , Difração de Raios X
6.
J Ethnopharmacol ; 254: 112669, 2020 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-32087316

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: The development of new inhibitors of bacterial virulence factors from natural origin has recently received significant attention. Callistemon citrinus Skeels is an important plant of great medicinal value. Its antimicrobial activity is well documented. Although several compounds were isolated from this plant, the actual bioactive compounds responsible for its antimicrobial activity are still unrevealed. AIM OF THE STUDY: To evaluate the effect of C. citrinus crude extract and isolated compounds on methicillin-resistant and sensitive Staphylococcus aureus. MATERIALS AND METHODS: The methylene chloride-methanol extract (MME) of C. citrinus leaves was prepared by Soxhlet apparatus. Biologically guided fractionation of MME was accomplished using several normal and reversed phase silica gel columns. The potency of MME and its isolated compounds against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) was evaluated. In addition, the mechanism of resistance was studied using three virulence factors; antibiofilm activity, inhibition of staphyloxanthin biosynthesis and effect on acid tolerance. Ultrastructural changes in MRSA and MSSA were observed by TEM to understand mode of action of these compounds. RESULTS: Pulverulentone A (C1), 8- desmethyl eucalyptin (C2) and eucalyptin (C3) were isolated from the most bioactive fraction of MME. Confocal scanning laser microscopy images revealed that C. citrinus isolated compounds destroyed the intact architecture of biofilm, thickness and reduced its biomass. Pulverulentone A (C1) showed the most potent anti-biofilm activity up to 71% and 62.3% against MRSA and MSSA, respectively. It also exhibited the highest inhibition of staphyloxanthin biosynthesis of MRSA and MSSA by 55.6% and 54.5%, respectively. The bacterial cell membrane was compromised, losing its integrity and releasing important cellular constituents when exposed to C1-C3 CONCLUSIONS: C. citrinus phenolics and acylphloroglucinols may serve as potential source of plant-based antibacterials and thus could be implicated to control MRSA biofilm formation.


Assuntos
Biofilmes/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Myrtaceae/química , Extratos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Xantofilas/antagonistas & inibidores , Staphylococcus aureus Resistente à Meticilina/ultraestrutura , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão e Varredura , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Folhas de Planta/química , Staphylococcus aureus/ultraestrutura
7.
Arq. Inst. Biol ; 87: e0152019, 2020. tab
Artigo em Inglês | VETINDEX, LILACS | ID: biblio-1130052

RESUMO

Root-knot nematode is one of the most important phytosanitary problems for Conilon coffee, as it reduces productivity and is difficult to handle. We aimed at studying the infectivity and damage caused by M. incognita race 1 in the "Jequitibá Incaper 8122" intermediate maturity coffee variety. The experiment was conducted in a greenhouse, in completely randomized design, with five replicates. The clones composing the variety "Jequitibá Incaper 8122" were inoculated with 2,000 eggs + second-stage juveniles of M. incognita race 1. Uninoculated plants were the control. Evaluations were performed 180 days after inoculation, considering the plant height (H), stem diameter (SD), number of leaves (NOL), leaf area (LA), number of plagiotropic branches (NPB), number of nodes (NN), chlorophyll content (CHLO), shoot dry matter (SDM), root fresh matter (RFM), final population (FNP), and reproduction factor (NRF). The nematode reduced NOL in clones 208 and 209, NRF in clones 201, 203, 207 and 208, NN in clones 203, 207, 208 and 209, CHLO in clones 201, 204, 206, 207 and 209, SDM in clones 201, 203, 204 and 205 and RFM in clones 205 and 207. M. incognita race 1 FNP and NRF were larger in clones 208, 201, 207 and 203. Clone 202 had FNP and NRF equal to zero, being immune to the nematode. Clone 206 presented the lowest NRF value among clones parasitized by M. incognita.(AU)


O nematoide-das-galhas é um dos mais importantes problemas fitossanitários para o cafeeiro conilon, por reduzir a produtividade e ser de difícil manejo. Objetivou-se estudar a infectividade e os danos causados por M. incognita raça 1 na variedade de café conilon de maturação intermediária "Jequitibá Incaper 8122". O experimento foi conduzido em casa de vegetação, em DIC, com cinco repetições. Os clones que compõem a variedade "Jequitibá Incaper 8122" foram inoculados com 2.000 ovos + juvenis de segundo estádio de M. incognita raça 1. Plantas não inoculadas constituíram a testemunha. As avaliações foram realizadas 180 dias após a inoculação, sendo avaliados: altura da planta (ALT), diâmetro do caule (DCA), número de folhas (NFO), área foliar (AFO), número de ramos plagiotrópicos (NRP), número de nós (NN), teor de clorofila (CLO), massa seca da parte aérea (MSA), matéria fresca da raiz (MFR), população final (PFN) e fator de reprodução (FRE). O nematoide reduziu o NFO nos clones 208 e 209, NRP nos clones 201, 203, 207 e 208, NN nos clones 203, 207, 208 e 209, CLO nos clones 201, 204, 206, 207 e 209, MSA nos clones 201, 203, 204 e 205 e MFR nos clones 205 e 207. PFN e FRE de M. incognita raça 1 foram maiores nos clones 208, 201, 207 e 203; o clone 202 teve a PFN e a FRE igual a zero, apresentando-se imune ao nematoide. O clone 206 apresentou o menor valor de FRE entre os clones parasitados por M. incognita.(AU)


Assuntos
Indústria do Café , Coffea , Nematoides , Tylenchoidea , Controle de Pragas , Células Clonais , Microscopia Eletrônica de Transmissão e Varredura , Café , Pragas da Agricultura
8.
Braz. J. Pharm. Sci. (Online) ; 56: e18327, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1132053

RESUMO

Hypericum sinaicum L. is an endangered Egyptian medicinal plant of high importance due to the presence of naphthodianthrones (hypericins), which have photodynamic properties and pharmaceutical potential. We sought to assess H. sinaicum ability to develop hairy roots that could be cultured in contained conditions in vitro and used as a source for hypericin production. We used four A. rhizogenes strains differing in their plasmids and chromosomal backgrounds to inoculate excised H. sinaicum root, stem and leaf explants to induce hairy root development. Additionally, inoculum was applied to shoots held in Rockwool cubes supporting their stand after removal of the root system. All explant types were susceptible to A. rhizogenes although stem explants responded more frequently (over 90%) than other explant types. The A4 and A4T A. rhizogenes strains were highly, and equally effective in hairy root induction on 66-72% of explants while the LBA1334 strain was the most effective in transformation of shoots. Sonication applied to explants during inoculation enhanced the frequency of hairy root development, the most effective was 60 s treatment doubling the percentage of explants with hairy roots. However, shoot transformation was the most effective approach as shoots developed hairy roots within 10 days after inoculation. Molecular analyses confirmed that the established hairy root cultures in vitro were indeed obtained due to a horizontal gene transfer from bacteria. These cultures grew fast and the hypericin content in hairy roots was about two fold higher than in H. sinaicum plants as determined by HPLC.


Assuntos
Plantas Medicinais/classificação , Raízes de Plantas/efeitos adversos , Hypericum/efeitos adversos , Agrobacterium/metabolismo , Plasmídeos , Técnicas In Vitro/instrumentação , Preparações Farmacêuticas/análise , Cromatografia Líquida de Alta Pressão/métodos , Microscopia Eletrônica de Transmissão e Varredura/métodos
9.
Mol Pharm ; 16(8): 3577-3587, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31291120

RESUMO

Engineered superparamagnetic iron oxide nanoparticles (SPIONs) have been studied extensively for their localized homogeneous heat generation in breast cancer therapy. However, challenges such as aggregation and inability to produce sub-10 nm SPIONs limit their potential in magnetothermal ablation. We report a facile, efficient, and robust in situ method for the synthesis of SPIONs within a poly(ethylene glycol) (PEG) reactor adsorbed onto reduced graphene oxide nanosheets (rGO) via the microwave hydrothermal route. This promising modality yields crystalline, stable, biocompatible, and superparamagnetic PEGylated SPION-rGO nanocomposites (NCs) with uniform dispersibility. Our findings show that rGO acts as a breeding ground for the spatially distributed nanosites around which the ferrihydrite seeds accumulate to ultimately transform into immobilized SPIONs. PEG, in parallel, acts as a critical confining agent physically trapping the accumulated seeds to prevent their aggregation and create multiple domains on rGO for the synthesis of quantum-sized SPIONs (9 ± 1 nm in diameter). This dual functionality (rGO and PEG) exhibits a pronounced effect on reducing both the aggregation and the sizes of fabricated SPIONs as confirmed by the scanning transmission electron microscopy images, dynamic light scattering analyses, and the specific absorption rates (SARs). Reduced aggregation lowered the toxicity of NCs, where PEGylated SPION-rGO NCs are more biocompatible than PEGylated SPIONs, showing no significant induction of cell apoptosis, mitochondrial membrane injury, or oxidative stress. Significantly less lactate dehydrogenase release and hence less necrosis are observed after 48 h exposure to high doses of PEGylated SPION-rGO NCs compared with PEGylated SPIONs. NCs induce local heat generation with a SAR value of 1760 ± 97 W/g, reaching up to 43 ± 0.3 °C and causing significant MCF-7 breast tumor cell ablation of about 78 ± 10% upon applying an external magnetic field. Collectively, rGO and PEG functionalities have a synergistic effect on improving the synthesis, stability, biocompatibility, and magnetothermal properties of SPIONs.


Assuntos
Neoplasias da Mama/terapia , Técnicas de Química Sintética/instrumentação , Química Farmacêutica/instrumentação , Nanopartículas de Magnetita/química , Nanocompostos/química , Técnicas de Química Sintética/métodos , Química Farmacêutica/métodos , Difusão Dinâmica da Luz , Feminino , Grafite/química , Humanos , Hipertermia Induzida/instrumentação , Hipertermia Induzida/métodos , Células MCF-7 , Magnetoterapia/instrumentação , Magnetoterapia/métodos , Nanopartículas de Magnetita/uso terapêutico , Nanopartículas de Magnetita/ultraestrutura , Teste de Materiais , Microscopia Eletrônica de Transmissão e Varredura , Nanocompostos/uso terapêutico , Nanocompostos/ultraestrutura , Tamanho da Partícula , Polietilenoglicóis/química
10.
Int J Low Extrem Wounds ; 18(3): 323-335, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31140339

RESUMO

Tissue regeneration has become a promising strategy for repairing damaged skin tissues. Among the hydrogels for tissue regeneration applications, topical hydrogels have demonstrated great potential for use as 3D-scaffolds in the burn wound healing process. Currently, no report has been published specifically on icariin-loaded polyvinyl alcohol (PVA)/agar hydrogel on full-thickness burn wounds. In the present study, burn tissue regeneration based on biomimetic hydrogel scaffolds was used for repairing damaged extracellular matrix. Furthermore, a skin burn model was developed in rats, and the icariin-loaded PVA/agar hydrogels were implanted into the damaged portions. The regeneration of the damaged tissues with the help of the icariin-loaded hydrogel group exhibited new translucent skin tissues and repaired extracellular matrix, indicating that the hydrogel can enhance the wound healing process. Moreover, characterization studies such as X-ray diffraction, Fourier-transformed infrared spectroscopy, and differential scanning calorimetry reported the extent of compatibility between icariin and its polymers. Results of the field emission scanning electron microscopy images revealed the extent of the spread of icariin within the polymer-based hydrogel. Furthermore, the wound healing potential, confirmed by histopathological and histochemical findings at the end of 21 days, revealed the visual evidence for the biomimetic property of icariin-loaded PVA/agar hydrogel scaffolds with the extracellular matrix for tissue regeneration.


Assuntos
Queimaduras , Flavonoides/farmacologia , Regeneração/efeitos dos fármacos , Lesões dos Tecidos Moles , Cicatrização , Animais , Queimaduras/patologia , Queimaduras/terapia , Varredura Diferencial de Calorimetria/métodos , Medicamentos de Ervas Chinesas , Excipientes/farmacologia , Microscopia Eletrônica de Transmissão e Varredura/métodos , Modelos Animais , Álcool de Polivinil/farmacologia , Ratos , Lesões dos Tecidos Moles/diagnóstico por imagem , Lesões dos Tecidos Moles/patologia , Lesões dos Tecidos Moles/terapia , Alicerces Teciduais , Resultado do Tratamento , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia
11.
Chembiochem ; 20(6): 822-830, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30501011

RESUMO

Staining compounds containing heavy elements (electron dyes) can facilitate the visualization of DNA and related biomolecules by using TEM. However, research into the synthesis and utilization of alternative electron dyes has been limited. Here, we report the synthesis of a novel DNA intercalator molecule, bis-acridine uranyl (BAU). NMR spectroscopy and MS confirmed the validity of the synthetic strategy and gel electrophoresis verified the binding of BAU to DNA. For TEM imaging of DNA, two-dimensional DNA origami nanostructures were used as a robust microscopy test object. By using scanning transmission electron microscopy (STEM) imaging, which is favored over conventional wide-field TEM for improved contrast, and therefore, quantitative image analysis, it is found that the synthesized BAU intercalator can render DNA visible, even at the single-molecule scale. For comparison, other staining compounds with a purported affinity towards DNA, such as dichloroplatinum, cisplatin, osmium tetroxide, and uranyl acetate, have been evaluated. The STEM contrast is discussed in terms of the DNA-dye association constants, number of dye molecules bound per base pair, and the electron-scattering capacity of the metal-containing ligands. These findings pave the way for the future development of electron dyes with specific DNA-binding motifs for high-resolution TEM imaging.


Assuntos
Acridinas/química , Complexos de Coordenação/química , DNA/química , Substâncias Intercalantes/química , Imagem Individual de Molécula/métodos , Acridinas/síntese química , Complexos de Coordenação/síntese química , Substâncias Intercalantes/síntese química , Microscopia Eletrônica de Transmissão e Varredura/métodos , Conformação de Ácido Nucleico , Urânio/química
12.
ACS Appl Mater Interfaces ; 10(43): 36733-36745, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30286290

RESUMO

In the current scenario, nanotechnological applications in the agriculture sector showing potential impacts on the improvement of plant growth in terms of protection and safety are at a very nascent stage. The present study deals with the synergistic role of zinc (Zn) and multiwalled carbon nanotubes (MWCNTs) synthesized as a zinc oxide (ZnO)/MWCNT nanocomposite, a prospective applicant to modulate the micronutrient supply and enhance the growth of onion seeds, thereby replacing harmful, unsafe chemical fertilizers. To the best of our knowledge, this is the first report wherein MWCNTs have been envisaged as a micronutrient distributor and a nutrient stabilizer enhancing the growth of onion plant under arid conditions. The growth trend of onion seeds was evaluated in an aqueous medium with varied concentrations of (i) MWCNTs, (ii) zinc oxide nanoparticles, and (iii) ZnO/MWCNT nanocomposites. ZnO/MWCNT nanocomposites with 15 µg/mL concentration displayed the best seedling growth with the maximum number of cells in telophase. A significant growth trend with increased concentration of ZnO/MWCNTs displayed no negative impact on plant growth in contrast to that with the use of MWCNTs. The synergistic impact of Zn nanoparticles and MWCNTs in ZnO/MWCNT nanocomposites on the rate of germination was explained via a mechanism supported by scanning transmission electron microscopy.


Assuntos
Micronutrientes/química , Nanocompostos/química , Nanotubos de Carbono/química , Sementes/crescimento & desenvolvimento , Zinco/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão e Varredura , Microscopia Eletrônica de Transmissão , Cebolas , Análise Espectral Raman , Propriedades de Superfície , Termogravimetria , Oligoelementos/química , Água/química , Óxido de Zinco/química
13.
Sci Rep ; 8(1): 4202, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29523802

RESUMO

Polygonumins A, a new compound, was isolated from the stem of Polygonum minus. Based on NMR results, the compound's structure is identical to that of vanicoside A, comprising four phenylpropanoid ester units and a sucrose unit. The structure differences were located at C-3″″'. The cytotoxic activity of polygonumins A was evaluated on several cancer cell lines by a cell viability assay using tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The compound showed the highest antiproliferative (p < 0.05) activities against K562 (Human Leukaemia Cell Line), MCF7 (Human breast adenocarcinoma cell line), and HCT116 (Colorectal cancer cells) cells. Cytotoxic studies against V79-4 cells were carried out and showed that polygonumins A was toxic at 50 µg/ml, suggesting that this compound may be used as an anticancer drug without affecting normal cells. Polygonumins A also showed promising activity as an HIV-1 protease inhibitor with 56% relative inhibition. Molecular docking results indicated that the compound possesses high binding affinity towards the HIV protease over the low binding free energy range of -10.5 to -11.3 kcal/mol. P. minus is used in Malaysian traditional medicine for the treatment of tumour cells. This is the first report on the use of P. minus as an HIV-1 protease inhibitor.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Inibidores da Protease de HIV/química , Inibidores da Protease de HIV/farmacologia , Caules de Planta/química , Polygonum/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cinamatos/química , Protease de HIV/química , Protease de HIV/metabolismo , Inibidores da Protease de HIV/isolamento & purificação , Inibidores da Protease de HIV/metabolismo , Humanos , Microscopia Eletrônica de Transmissão e Varredura , Simulação de Acoplamento Molecular , Domínios Proteicos
14.
Geobiology ; 16(1): 88-103, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29322690

RESUMO

Through the use of scanning transmission electron microscopy (STEM) combined with other complementary techniques (SEM, cryo-TEM, HRTEM, and EELS), we have studied the interaction of microorganisms inhabiting deep anoxic waters of acidic pit lakes with dissolved aluminum, silica, sulfate, and ferrous iron. These elements were close to saturation (Al, SiO2 ) or present at very high concentrations (0.12 m Fe(II), 0.12-0.22 m SO42- ) in the studied systems. The anaerobic conditions of these environments allowed investigation of geomicrobial interactions that are difficult to see in oxidized, Fe(III)-rich environments. Detailed chemical maps and through-cell line scans suggest both extra- and intracellular accumulation of Al, Si, S, and Fe(II) in rod-like cells and other structures (e.g., spherical particles and bacteriomorphs) of probable microbial origin. The bacterial rods showed external nanometric coatings of adsorbed Fe(II) and Al on the cell surface and cell interiors with significant presence of Al, Si, and S. These microbial cells coexist with spherical particles showing similar configuration (Fe(II) external coatings and [Al, Si, S]-rich cores). The Al:Si and Al:S ratios and the good Al-Si correlation in the cell interiors suggest the concurrent formation of two amorphous phases, namely a proto-aluminosilicate with imogolite-like composition and proto-hydrobasaluminite. In both cases, the mineralization appears to comprise two stages: a first stage of aluminosilicate and Al-hydroxysulfate precipitation within the cell or around cellular exudates, and a second stage of SO42- and Fe(II) adsorption on surface sites existing on the mineral phases in the case of (SO42- ) or on presumed organic molecules [in the case of Fe(II)]. These microbially related solids could have been formed by permineralization and mineral replacement of senescent microbial cells. However, these features could also denote biomineralization by active bacterial cells as a detoxification mechanism, a possibility which should be further explored. We discuss the significance of the observed Al/microbe and Si/microbe interactions and the implications for clay mineral formation at low pH.


Assuntos
Silicatos de Alumínio/metabolismo , Precipitação Química , Microbiologia da Água , Silicatos de Alumínio/química , Anaerobiose , Compostos Ferrosos/química , Concentração de Íons de Hidrogênio , Microbiota , Microscopia Eletrônica de Transmissão e Varredura , Solubilidade , Sulfatos/química
15.
World J Gastroenterol ; 23(24): 4369-4380, 2017 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-28706419

RESUMO

AIM: To investigate the effects of Ground Cherry (Physalis angulata L.) standardized supercritical CO2 extract in trinitrobenzenesulphonic acid (TNBS) model of rat intestinal inflammation. METHODS: The animals were divided into groups that received vehicle or P. angulata extract (PACO2) orally at the doses 25, 50 and 100 mg/kg daily by 5 d before TNBS damage. Protective effects of PACO2 were assessed by macroscopic analysis, biochemical determinations of the levels of myeloperoxidase (MPO), alkaline phosphatase (ALP), glutathione and cytokines (such as INF-γ, IL-1ß, IL-6, IL-10 and TNF-α), gene expression evaluation (including Hsp70, heparanase, NF-κB, mitogen-activated protein kinases (Mapk) 1, 3, 6 and 9, and the mucins genes Muc 1, 2, 3 and 4) and histopathological studies using optical, and electronic (transmission and scanning) microscopy. RESULTS: PACO2 extract promoted a significant reduction in MPO and ALP activities, reducing oxidative stress and neutrophil infiltration. These effects were accompanied by significant reduction of colonic levels of IFN-γ and IL-6 and down-regulation of heparanase, Hsp70, Mapk3, Mapk9, Muc1 and Muc2 genes expression when compared with TNBS-control animals. In addition, protective effects were also evidenced by reduced neutrophil infiltration, recovery of cell architecture and replacement of mucin by histopathological and ultrastructural analysis. CONCLUSION: Physalis angulata supercritical CO2 extract is an intestinal anti-inflammatory product that modulates oxidative stress, immune response and expression of inflammatory mediators, with potentially utility for treating inflammatory bowel disease.


Assuntos
Anti-Inflamatórios/uso terapêutico , Colite/tratamento farmacológico , Physalis/química , Extratos Vegetais/uso terapêutico , Administração Oral , Fosfatase Alcalina/metabolismo , Animais , Dióxido de Carbono/química , Cromatografia com Fluido Supercrítico , Colite/induzido quimicamente , Colite/patologia , Colo/enzimologia , Colo/patologia , Colo/ultraestrutura , Citocinas/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Mucosa Intestinal/enzimologia , Mucosa Intestinal/patologia , Mucosa Intestinal/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão e Varredura , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Infiltração de Neutrófilos/efeitos dos fármacos , Peroxidase/metabolismo , Ratos , Ratos Wistar , Ácido Trinitrobenzenossulfônico/toxicidade
16.
Biochim Biophys Acta Gen Subj ; 1861(6): 1578-1586, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27919801

RESUMO

BACKGROUND: This work is focused on mechanisms of uptake in cancer cells of rationally designed, covalently assembled nanoparticles, made of superparamagnetic iron oxide nanoparticles (SPIONs), fluorophores (doxorubicin or Nile Blue), polyethylene glycol (PEG) and folic acid (FA), referred hereinafter as SFP-FA. METHODS: SFP-FA were characterized by DLS, zetametry and fluorescence spectroscopy. The SFP-FA uptake in cancer cells was monitored using fluorescence-based methods like fluorescence-assisted cell sorting, CLSM with single-photon and two-photon excitation. The SFP-FA endocytosis was also analyzed with electron microscopy approaches: TEM, HAADF-STEM and EELS. RESULTS: The SFP-FA have zeta potential below -6mW and stable hydrodynamic diameter close to 100nm in aqueous suspensions of pH range from 5 to 8. They contain ca. 109 PEG-FA, 480 PEG-OCH3 and 22-27 fluorophore molecules per SPION. The fluorophores protected under the PEG shell allows a reliable detection of intracellular NPs. SFP-FA readily enter into all the cancer cell lines studied and accumulate in lysosomes, mostly via clathrin-dependent endocytosis, whatever the FR status on the cells. CONCLUSIONS: The present study highlights the advantages of rational design of nanosystems as well as the possible involvement of direct molecular interactions of PEG and FA with cellular membranes, not limited to FA-FR recognition, in the mechanisms of their endocytosis. GENERAL SIGNIFICANCE: Composition, magnetic and optical properties of the SFP-FA as well their ability to enter cancer cells are promising for their applications in cancer theranosis. Combination of complementary analytical approaches is relevant to understand the nanoparticles behavior in suspension and in contact with cells.


Assuntos
Antibióticos Antineoplásicos/metabolismo , Neoplasias da Mama/metabolismo , Clatrina/metabolismo , Doxorrubicina/metabolismo , Portadores de Fármacos , Endocitose , Ácido Fólico/metabolismo , Magnetismo/métodos , Nanopartículas de Magnetita , Nanomedicina/métodos , Polietilenoglicóis/química , Neoplasias do Colo do Útero/metabolismo , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Cavéolas/metabolismo , Vesículas Revestidas por Clatrina/metabolismo , Doxorrubicina/química , Doxorrubicina/farmacologia , Endossomos/metabolismo , Feminino , Ácido Fólico/química , Células HeLa , Humanos , Lisossomos/metabolismo , Células MCF-7 , Nanopartículas de Magnetita/química , Microscopia Confocal , Microscopia Eletrônica de Transmissão e Varredura , Microscopia de Fluorescência por Excitação Multifotônica , Espectroscopia de Perda de Energia de Elétrons , Neoplasias do Colo do Útero/tratamento farmacológico
17.
Adv Mater ; 28(12): 2316-21, 2016 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-26755196

RESUMO

Large-area and highly crystalline CVD-grown multilayer MoSe2 films exhibit a well-defined crystal structure (2H phase) and large grains reaching several hundred micrometers. Multilayer MoSe2 transistors exhibit high mobility up to 121 cm(2) V(-1) s(-1) and excellent mechanical stability. These results suggest that high mobility materials will be indispensable for various future applications such as high-resolution displays and human-centric soft electronics.


Assuntos
Molibdênio/química , Selênio/química , Transistores Eletrônicos , Cristalização , Microscopia Eletrônica de Transmissão e Varredura , Espectroscopia Fotoeletrônica , Dióxido de Silício/química , Difração de Raios X
18.
Chem Commun (Camb) ; 52(8): 1563-6, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26691583

RESUMO

Herein, black phosphorus quantum dots and nanoparticles of a few layer thickness were prepared and characterized using STEM, AFM, dynamic light scattering, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy and photoluminescence. Impact electrochemistry of the induvidual black phosphorus nanoparticles allows their size determination. The centrifugation of colloidal black phosphorus nanoparticles allowed separation of quantum dots with sizes up to 15 nm. These black phosphorus nanoparticles exhibit a large band gap and are expected to find a wide range of applications from semiconductors to biomolecule tags. The use of black phosphorus nanoparticles for vapour sensing was successfully demonstrated.


Assuntos
Nanopartículas , Fósforo/química , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão e Varredura , Espectroscopia Fotoeletrônica , Análise Espectral Raman , Difração de Raios X
19.
Rev. bras. epidemiol ; 18(supl.2): 109-122, Out.-Dez. 2015. tab
Artigo em Inglês | LILACS | ID: lil-776706

RESUMO

RESUMO: Objetivo: Descrever indicadores de cuidado em saúde em adultos com hipertensão arterial autorreferida no Brasil, segundo características sociodemográficas. Métodos: Foram utilizados dados da Pesquisa Nacional de Saúde 2013, estudo transversal de base populacional, referentes ao cuidado em saúde com a hipertensão arterial autorreferida quanto ao uso de serviços de saúde. As prevalências e seus intervalos de confiança de 95% (IC95%) foram calculados segundo sexo, idade, raça/cor e escolaridade, representativos para Brasil e grandes regiões. Resultados: A hipertensão arterial foi referida por 21,4% (IC95% 20,8 - 22,0) dos entrevistados, sendo maior em mulheres e em pessoas sem instrução e com ensino fundamental incompleto. Dentre estes, 45,9% (IC95% 44,0 - 47,7) referiram ter recebido assistência médica pela última vez em uma Unidade Básica de Saúde; 81,4% (IC95% 80,1 - 82,7) referiram tomar medicamentos para a hipertensão; e 92,0% (IC95% 91,2 - 92,8) referiram ter realizado todos os exames complementares que foram solicitados. Conclusão: É importante conhecer a cobertura e o acesso aos serviços de saúde para o cuidado aos indivíduos com hipertensão arterial, de modo a avançar na qualidade da assistência prestada e reduzir as desigualdades identificadas.


ABSTRACT: Objective: To describe health care indicators in adults with self-reported hypertension in Brazil, according to socio-demographic characteristics. Methods: Data from the National Health Survey 2013, a cross-sectional population-based study, about health care of self-reported hypertension and health services were used. Prevalence and 95% confidence intervals (95%CI) were calculated for sex, age, race/color skin and schooling levels, representing Brazil and major regions. Results: Hypertension was reported by 21.4% (95%CI 20.8 - 22.0) of respondents, being higher in women and in people without instruction and incomplete middle school. Among these, 45.9% (95%CI 44.0 - 47.7) reported having received medical care for the last time in a basic health unit; 81.4% (95%CI 80.1 - 82.7) reported taking medication for high blood pressure; and 92.0% (95%CI 91.2 - 92.8) reported having taken all requested complementary examinations. Conclusion: It is important to know the coverage and access to health services for the care of patients with hypertension, in order to improve care quality and reduce identified inequalities.


Assuntos
Animais , Camundongos , Ratos , Barreira Hematoencefálica , Encéfalo/metabolismo , Nanotubos de Carbono , Técnicas de Cocultura , Técnicas In Vitro , Microscopia Eletrônica de Transmissão e Varredura , Nanotubos de Carbono/toxicidade , Ácido Pentético/farmacocinética , Ratos Wistar , Suínos
20.
J Phys Chem B ; 119(41): 13208-17, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26398329

RESUMO

Photochromic solid materials based on the cationic polymer poly(decylviologen) are reported. The solids were obtained by freeze-drying colloidal suspensions of nanocomplexes obtained by mixing aqueous solutions of the polycation with different solutions of polyanions such as poly(sodium 4-styrenesulfonate) or sodium alginate, at a cationic/anionic polymeric charge ratio of 0.7. The photochromic responses of the solid materials fabricated with alginate as complementary charged polyelectrolyte of the cationic polyviologen are faster than those of the solid materials fabricated with poly(sodium 4-styrenesulfonate), achieving coloration kinetics in the order of minutes, and discoloration kinetics in the order of hours for the former. Aromatic-aromatic interactions between the latter polyanion and the polyviologen may stabilize the dicationic form of the viologen derivative, increasing the necessary energy to undergo photoreduction, thus decreasing the reduction kinetics.


Assuntos
Alginatos/química , Polímeros/química , Ácidos Sulfônicos/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Microscopia Eletrônica de Transmissão e Varredura , Espectroscopia de Prótons por Ressonância Magnética
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