852 resultados para ANTIOXIDANT FLAVONOIDES
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Pós-graduação em Patologia - FMB
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Curcumin possesses wide-ranging anti-inflammatory and anti-cancer properties and its biological activity can be linked to its potent antioxidant capacity. Superparamagnetic maghemite (gamma-Fe2O3), called surface-active maghemite nanoparticles (SAMNs) were surface-modified with curcumin molecules, due to the presence of under-coordinated Fe-III atoms on the nanoparticle surface. The so-obtained curcumin-modified SAMNs (SAMN@curcumin) had a mean size of 13 +/- 4 nm. SAMN@curcumin was characterized by transmission and scanning electron microscopy, UV/Vis, FTIR, and Mossbauer spectroscopy, X-ray powder diffraction, bulk susceptibility (SQUID), and relaxometry measurements (MRI imaging). The high negative contrast proclivity of SAMN@curcumin to act as potential contrast agent in MRI screenings was also tested. Moreover, the redox properties of bound curcumin were probed by electrochemistry. SAMN@curcumin was studied in the presence of different electroactive molecules, namely hydroquinone, NADH and ferrocyanide, to assess its redox behavior. Finally, SAMN@curcumin was electrochemically probed in the presence of hydrogen peroxide, demonstrating the stability and reactivity of bound curcumin.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Flavonoides são constituintes fenólicos de plantas que possuem diversas atividades terapêuticas, dentre elas, a atividade antimutagênica. Eles são caracterizados por um esqueleto carbônico C6-C3-C6, em que os componentes C6 são anéis aromáticos e o C3 um anel heterocíclico. Diferenças nessa estrutura podem alterar a atividade e o seu potencial antimutagênico. Para melhor compreensão da atividade antimutagênica exercida pelos flavonoides, neste estudo, os compostos quercetina, kaempferol, luteolina, fisetina, galangina, crisina, flavona, 3-hidroxiflavona, 5-hidroxiflavona e 7-hidroxiflavona, flavonoides que apresentam diferenças no padrão de hidroxilação, foram analisados pelo teste de Ames. Para realização dos ensaios foram utilizadas as cepas TA98, TA100 e TA102 de Salmonella typhimurium em testes com e sem ativação metabólica. Os mutágenos utilizados para comparação do efeito protetor dos flavonoides foram 4-nitro-o-fenilenodiamina (NPD), azida sódica (AZS), mitomicina C (MMC), benzo[a]pireno (B[a]P), aflatoxina B1 (AFB1) e 2-aminoantraceno (2-AA). No ensaio contra o NPD sem ativação metabólica, todos os flavonoides apresentaram efeito antimutagênico, com exceção da fisetina. No ensaio com ativação metabólica contra o B[a]P, todos os flavonoides demonstraram forte efeito antimutagênico, com exceção da quercetina que potencializou o efeito mutagênico do mutágeno. No ensaio contra a AZS sem ativação metabólica, os flavonoides luteolina, crisina, 3-hidroxiflavona e 7-hidroxiflavona reduziram a resposta mutagênica do mutágeno. No ensaio contra a AFB1 com ativação metabólica, os flavonoides kaempferol, luteolina, crisina e galangina (em concentrações mais elevadas) exibiram efeito antimutagênico ...
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Coleus blumei Benth (Lamiaceae), popularly known in Brazil as heart-hurt or coleus-of-Java is an ornamental plant widely used due to the color of its leaves. Several species of the genus Coleus present compounds with antioxidant, antimicrobial and allopathic activities due to the presence of chemicals such coleonol, forskolin and rosmarinic acid. Therefore, this study aimed to carry out phytochemical study and biological tests to evaluate the antibacterial, antioxidant and allopathic activities of the 70% ethanol extract and its fractions ethyl acetate, dichloromethane and end aqueous fraction leaf of Coleus blumei Benth. The plant extract was prepared by turbolisis from the powder of dried leaves, as a solvent for extraction using 70% ethanol. The ethanol extract was fractionated with solvents dichloromethane and ethyl acetate. The phytochemical study identified the presence of saponins, free anthraquinones, flavonoids and anthocyanidins. In evaluating the antibacterial dichloromethane fraction showed activity against all microorganisms tested both in agar diffusion test and microdilution test. The 70% ethanol extract showed activity against the micro-organisms S. aureus and S. epidermidis in agar diffusion test and against all microorganisms tested in microdilution test. The ethyl acetate fraction showed activity against the micro-organism S. aureus in the agar diffusion test and against all microorganisms tested in microdilution test. The end aqueous fraction showed no activity against any micro-organism tested. In the test of evaluation activity allopathic dichloromethane fraction showed greater inhibition of seed germination and growth of tomato (Lycopersicon esculentum Mill), followed by 70% ethanolic extract, the ethyl acetate fraction and the end aqueous fraction. In testing the antioxidant activity with DPPH ethyl acetate fraction showed higher antioxidant activity followed... (Complete abstract click electronic access below)
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Phenolic compounds represent one of the main groups of secondary metabolites. Due to their chemical diversity, they have a variety of functions in plants, such as protection against ultraviolet radiation, herbivores and pathogens, and attraction of pollinators or dispersers of fruits and seeds. For human, the phenolic compounds are used like food colorings and flavors and, due to their pharmacological properties, mainly to antioxidant activity, they are associated with several health benefits, such as delay senility, prevention and therapy of cardiovascular diseases and of some cancers. The grapes are considered one of the main source of phenolic compounds and the fruit and its products are consumed in Brazil and worldwide. Considering the phenolic compounds diversity and their different distribution in the grape parts, this work had like aims the extraction, identification and quantification of the main classes of phenolic compounds of 10 grape varieties. The content of total phenols, flavanols and anthocyanins were determined, respectively, according to the Folin-Ciocalteu, DMACA and comparison of pH spectrophotometric methods. The content of total phenols varied from 142.75 + 1.86 to 483.39 + 5.90 mg.L-1 in the peel and from 86.50 + 0.54 to 146.32 + 9.97 mg.L-1 in the pulp. The amount of total flavanols varied from 3.68 + 0.03 to 6.92 + 0.26 mg.L-1 in the peel and from 0.90 + 0.00 to 1.36 + 0.00 mg.L-1 in the pulp. The content of total anthocyanins varied from 7.00 + 0.99 to 406.56 + 39.50 mg.L-1 in the peel and from 2.88 + 0.28 to 46.36 + 1.89 mg.L-1 in the pulp. The phenolic compounds concentration was higher in the peel than in the pulp. The total phenols and anthocyanins varied a lot while the total flavanols were more constant. The flavanols represent the smaller portion of phenolic compounds
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The stomach is an exceptional organ, which functions are sterilize food ingested, form the primitive bolus, digest lipids and proteins, and to store food temporarily in the gastrointestinal tract. Its capacity of digesting food without digesting itself is amazing. This fact occurs due to innumerous protective substances adjacent to the gastric mucosa. When aggressive factors overwhelm the protective factors, a lesion in the gastric mucosa is formed. Lesions that reach the lamina propria are called gastric ulcers, which are classified macroscopically as openings on the gastric wall and; microscopically, as a gastric injury characterized with epithelial desquamation, mucosal hemorrhage, glandular damage and eosinophilic infiltration. The current therapy available is effective, although it causes collateral effects, therefore researching new drugs is necessary. This work aim to evaluate the gastroprotective effect of epicatechin against gastric lesions induced by absolute ethanol and non steroidal anti-inflammatory drugs which are the main causes of this disease currently, yet we aim to study the main mechanisms of action responsible for the gastroprotective effect. The results show that epicatechin has a significant macroscopic and microscopic gastroprotective effect against gastric injuries induced by ethanol and indomethacin, acting locally by augmenting gastric mucus secretion and it also acts via antioxidant system by holding total glutathione levels. Epicatechin’s gastroprotective mechanisms depend on the activation of sulfhydryl compounds and doesn’t depend on the NO-synthase enzyme
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Pós-graduação em Biociências - FCLAS