Navegando por Assunto "Produtos naturais"

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Acesso aberto (Open Access)
Efeito de uma espécie do gênero Varronia sobre a viabilidade celular, atividade antimicrobiana, toxicidade dérmica aguda e o processo de cicatrização (in vitro e in vivo)
(Universidade Federal do Pará, 2019-09-09) RIBERA, Paula Cardoso; FONTES JÚNIOR, Enéas de Andrade; http://lattes.cnpq.br/7056265073849866; https://orcid.org/ 0000-0002-6186-9581
Tissue damage, particularly to the skin, results in damage to cell structures, layers, and lineages to the fullest extent. Under these conditions, wound healing is the physiological process responsible for tissue repair. Inflammation is an important stage in tissue repair and; therefore, a strong target for clinical studies. The species Varronia multispicata is popularly used for the treatment of bruises, with recently discovered anti-inflammatory and analgesic effects. The present work aimed to investigate the effect of aqueous extract of Varronia multispicata leaves (VAR01) on cell viability, antimicrobial analysis, dermal toxicity, and in vitro and in vivo healing. In the in vitro assays, there were evaluated the cell viability in BALB/c 3T3 murine fibroblasts, the antimicrobial action by the microdilution method for determination of minimum inhibitory concentration and petri dish culture technique for the minimum bactericidal concentration. Healing assays were performed in cultured fibroblast monolayers. For in vivo assays in the dermal toxicity test, female Wistar rats were used and divided into the following groups: saline, 100mg/ml, 200mg/ml, and 1000mg/ml of VAR01; as for healing evaluation, Mus musculus mice were used and divided into 4 groups: sham, negative control, treated (VAR01 10%), and positive control (Dersani®). V. multispicata kept the cells viable for 24h, with reduction of fibroblasts in the 48h period at a concentration of 500 µg/ml. It showed no antimicrobial activity, presented in vitro and in vivo injury contraction capacity, did not promote death or behavioral changes, did not cause changes in water and feed intake, weight gain, relative weight, and organ histological analysis, showed a reduction in alkaline phosphatase concentrations in the group treated with 100 mg/ml extract when compared as control group. It was also revealed a reduction in alanine aminotransferase levels in the 100 mg/ml extract-treated group when compared to the control group. However, a significant increase in TGP concentrations was found in the 200 mg/ml group when compared to the control group. While assessing the degree of irritation, VAR01 did not show an irritant profile when administered acutely topically. Therefore, the extract is safe and of low toxicity, promising in the process of tissue regeneration with possible modulation in the inflammatory pathway, being a stimulating result for the following steps of biological activity evaluation and elucidation of the healing process.
Acesso aberto (Open Access)
Estudo da composição química e atividades biológicas de óleos essenciais de Piper divaricatum, Syzygium aromaticum e Siparuna guianensis
(Universidade Federal do Pará, 2018-12-17) OLIVEIRA, Mozaniel Santana de; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
The present thesis brings three literature review studies, where we show the use of supercritical CO2 to obtain essential oils from different aromatic plants. In addition, the different biological applications of essential oils such as antibacterial, antifungal, antioxidants, anticancer, antiparasitic, anti-inflammatory and phytotoxic. Based on these studies, three research manuscripts were made. The first reports the use of supercritical CO2 in different combinations of temperature and pressure: 35 and 55 °C and 100, 300 and 500 bar. We also report the use of the hydrodistillation process to obtain fractions of the essential oil Piper divaricatum. Mass extracts, chemical composition, antioxidant activity and acetylcholinesterase inhibitory activity (AChE) were analyzed. Supercritical CO2 extraction showed better efficiency in obtaining essential oil compared to hydrodistillation. The 55/500 bar isotherm resulted in the highest bulk yield of 7.40 0.08 %. Methyl eugenol was the compound with the highest concentration ranging from 48.01 to 61.85%, the fraction obtained in the condition of 35 ºC / 300 bar being the most effective in relation to the antioxidant activity, with values of 34.69 ± 1.38 % (DPPH) and 296.86 ± 8.96 (mgTrolox / mL) (ABTS), respectively. Ligands, following molecular coupling, exhibited molecular positions that promoted interactions with different amino acid residues that are important for enzymatic catalysis with His447. The second article discusses the cytotoxic, antimicrobial activity and mechanism of action of the major component of the essential oil of Syzygium aromaticum obtained by supercritical CO2. In this work, gingival fibroblasts were exposed to the essential oil in different concentrations for one hour: 5 μL / ml, 7.5 μL / ml and 10 μL / ml. The culture medium was used as control. Cytotoxicity analysis was performed using the 3(4,5dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT®) method. Susceptibility was evaluated in three microorganisms Candida albicans, Escherichia coli and Staphylococcus aureus. Statistical analyzes showed a significant difference in cell viability for the concentration of 10 μL / mL, in relation to the control group. As a result, the plant extract showed no cytotoxicity at concentrations below 10 μL / mL in human gingival fibroblasts. The interaction mode of eugenol, the main compound and main component responsible for the biological activity of the essential oil, was evaluated. Molecular anchoring of eugenol with important metabolic pathway proteins of C. albicans, E. coli and S. aureus microorganisms were performed. The results demonstrated that the compound is capable of interacting with catalytic residues of the enzymes and forming an energetically favorable system with such proteins. The results of the free energy binding obtained demonstrate this ability. For the eugenol-N-myristoyltransferase system (C. albicans), the ΔGbin value was - 19.01 kcal / mol, for the Enoil reductase (E. Coli) ΔGbind was equal to -11.31 kcal / mol and for the SarA (S. aureus) ΔGbind was -13.58 kcal / mol. And in the third article we talked about the essential oil of Siparuna guianensis that oil was obtained by hydrodistillation. Identification of the chemical compounds was performed by gas chromatography coupled to mass spectrometry (GC/MS). The antimicrobial activity was performed in four microorganisms: Streptococcus mutans, (ATCC 3440), Enterococcus faecalis (ATCC 4083), Escherichia coli (ATCC 25922) and Candida albicans (ATCC-10231). The docking and molecular dynamics studies were performed with the highest concentration of target-drug proteins, 1ILA (C. albicans), 1C14 (E. coli), 2WE5 (E. faecalis) and 4TQX (S. mutans). The main compounds identified were: Elemene (7.58%), Curzereno (7.62%), Germacrene D (8.17%), β-Elemenone (12.76%) and Atratylone (18.96%). Gram-positive bacteria and fungi were the most susceptible to the effects of essential oil. The results obtained in the simulation showed that the main compound atratylone interacts with the catalytic sites of the target proteins, forming energetically favorable systems and remaining stable during the period of11 molecular dynamics. The results presented by the essential oils of the three species studied in the present thesis show that they have applications in several areas of knowledge as for the control of microorganisms and as a preservative in the food industry because it has antioxidant action, free radical control, and as possible agents promoting neuroprotective activity being used primarily for the inhibition of acetylcholinesterase, retarding the hydrolysis of acetylcholine, thereby improving cholinergic manifestations in the synaptic clefts of the human brain
Acesso aberto (Open Access)
Estudo da técnica de infusão de resina aplicada à fabricação de compósitos de matriz poliéster reforçados por fibras naturais da Amazônia
(Universidade Federal do Pará, 2014-03-26) RODRIGUES, Jean da Silva; FUJIYAMA, Roberto Tetsuo; http://lattes.cnpq.br/3165747089941318; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
In this work were produced unsaturated polyester composites reinforced by fibers of curaua, jute and raffia, arranged in the form of fabric in plan style and aligned fibers. The composites were manufactured by resin infusion process, studying the main parameters that govern the manufacturing method, such as permeability and porosity of the reinforcement and architecture of infusion. Natural fibers were characterized according to their physical, morphological and mechanical properties. The curaua fiber reinforced composites were made using fibers in nature and treated by an alkaline NaOH solution at different concentrations. The composites were characterized in tests of tensile and impact strength, beyond of the determination of their physical properties such as density, porosity and volume fractions of the constituents. The results showed that the composites obtained better performance in tensile and impact were those reinforced with aligned curaua fibers manufactured under vacuum of 101.3 kPa. The evaluation of the cross section of the specimens showed that composites can provide partial saturation of wires or fiber reinforcement due to the vacuum level used mainly in reinforcements in the form of fabric with relatively larger diameter wires. The infusion process proved to be a good method of making composites reinforced with natural fibers, because in addition to being more environmentally friendly because it is a closed mold process, enabled the manufacture of products with high fiber content and good mechanical properties.