ABSTRACT The metabolism of ethanol occurs mainly in the liver, promoting increase of reactive oxygen species and nitrogen, leading to redox imbalance. Therefore, antioxidants can be seen as an alternative to reestablish the oxidizing/reducing equilibrium. The aim of this study was to evaluate the antioxidant and hepatoprotective effect of aqueous extract of Baccharis trimera (Less.) DC., Asteraceae, in a model of hepatotoxicity induced by ethanol. The extract was characterized and in vitro tests were conducted in HepG2 cells. It was evaluated the cells viability exposed to aqueous extract for 24 h, ability to scavenging the radical DPPH, besides the production of reactive oxygen species and nitric oxide, and the influence on the transcriptional activity of transcription factor Nrf2 (12 and 24 h) after exposure to 200 mM ethanol. The results showed that aqueous extract was non-cytotoxic in any concentration tested; moreover, it was observed a decrease in ROS and NO production, also promoting the transcriptional activity of Nrf2. In vivo, we pretreatment male rats Fisher with 600 mg/kg of aqueous extract and 1 h later 5 ml/kg of absolute ethanol was administrated. After two days of treatment, the animals were euthanized and lipid profile, hepatic and renal functions, antioxidant status and oxidative damage were evaluated. The treatment with extract improved liver function and lipid profile, reflecting the reduction of lipid microvesicules in the liver. It also promoted an increase of glutathione peroxidase activity, decrease of oxidative damage and MMP-2 activity. These results, analyzed together, suggest the hepatoprotective effect of B. trimera aqueous extract.

The synthesis of highly stable silver colloids has been successfully achieved by using reducing/stabilizer amino-functionalized polymers without the aid of any other external agent. The polymer coated inorganic nanoparticles have been detailed characterized via scattering, imaging and UV-Vis spectroscopy. The combination of transmission electron microscopy (TEM) and light scattering suggested nearly spherical structures stabilized by a lengthy polymeric shell with surface charge dependent on polymer nature and molecular weight. The hybrid nanomaterials are produced via an autocatalytic process where the onset of colloid formation is influenced by the available hydrophobic nitrogen units normalized by the weight of polymer. The induction period, however, does not influence the dimension of the metallic cores which are similar although with a high degree of dispersity. The coating confers a large hydrodynamic size to the silver nanoparticles and the length of the stabilizing shell is chiefly governed by the molecular weight of the amino-functionalized polymers. These features may significantly impact the cytotoxicity and bactericidal properties of the hybrid materials. These investigations are currently underway.

Este estudo buscou compreender os sistemas de significação socialmente construídos e compartilhados por grupos de idosos residentes em área urbana da região metropolitana de Belo Horizonte, Minas Gerais, sobre temas ambientais. A teoria das representações sociais foi o referencial que orientou o trabalho, na direção de um estudo comparativo entre dois grupos de terceira idade: o grupo Fonte de Vida, de Belo Horizonte, e o Clube Viver Melhor, do município de Betim. Foram entrevistados vinte idosos e as entrevistas foram analisadas na perspectiva da análise de conteúdo. As representações mostraram que os idosos têm percepção da degradação ambiental e apostam na cooperação, solidariedade e educação, em sentido amplo, e em sua participação como atores sociais, em contextos singulares, para o despertar de uma sensibilização ambiental.

The present study was dedicated to understanding the system of meanings socially constructed and shared by Third Age groups of people living in urban areas of the metropolitan region of Belo Horizonte, Minas Gerais State, Brazil. The theory of social representation was employed as a theoretical parameter to make comparisons between two third age groups, the Fonte Vida group from Belo Horizonte and the Clube Viver Melhor group from Betim. Twenty older citizens were interviewed and the outcomes analyzed using the content analysis. The representations showed that older people have understandings of environmental degradation and look broadly for cooperation, solidarity and education, in their participation as social players, and in a singular context, for ecological sensitization.