Study of antioxidant, antiproliferative and apoptosis-inducing properties of wild mushrooms from the Northeast of Portugal

Mushrooms are known as a powerful source of bioactive compounds including antioxidants, inhibitors of human tumour cell lines growth, inducers of apoptosis and enhancers of immunity. Indeed, many pre-clinical studies have been conducted in human tumour cell lines and in some cases a number of compounds isolated from mushrooms have followed to clinical trials. The Northeast of Portugal is one of the European regions with higher wild mushrooms diversity. However, to our knowledge, no studies had been conducted so far to verify their bioactivities. The main aim of this work was the evaluation of the bioactive properties (antioxidant properties and growth inhibitory potential on human tumour cell lines) of wild edible mushrooms collected in the Northeast of Portugal. Once properly identified, methanolic, ethanolic and boiling water extracts were prepared from thirty eight wild mushroom species collected in that region. Chemical characterization was obtained by high performance liquid chromatography (HPLC) coupled to a photodiode array detector (DAD) or to a refraction index detector (RI). Antioxidant activity assays were carried out in those extracts, including evaluation of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging capacity, reducing power and inhibition of β-carotene bleaching. Extract-induced cell growth inhibition was assessed with the sulforhodamine B assay in four human tumour cell lines (NCI-H460 - lung cancer, MCF-7 -breast cancer, HCT-15 -colon cancer and AGS - gastric cancer). The effects on cell cycle profile and apoptosis were evaluated by flow cytometry and the effect on the expression levels of proteins related to cell cycle and apoptosis was further investigated by Western blotting. Three wild edible mushroom species revealed growth inhibitory activity in the studied human tumour cell lines: Clitocybe alexandri ethanolic extract, Lepista inversa methanolic extract and Suillus collinitus methanolic extract. C. alexandri ethanolic extract induced an S-phase cell cycle arrest and increased the percentage of apoptotic cells, in the NCI-H460 cell line. The analysed mushroom species also provided interesting antioxidant potential, mainly the boiling water extract of L. inversa which showed the highest DPPH radical scavenging activity, reducing power and β-carotene bleaching inhibition. S. collinitus methanolic extract induced a slight increase in the number of cells in G1, with a concomitant decrease in the percentage of cells in the S phase of the cell cycle and an increase in the percentage of apoptotic cells, in the MCF-7 cell line. The combined use of the S. collinitus methanolic extract and etoposide caused a greater decrease in the percentage of cell growth, when compared to either of them used individually, indicating the potential benefit of this combination. The tested extracts were chemically characterized and protocatechuic, p-hydroxybenzoic, p-coumaric and cinnamic acids were the main compounds identified on the phenolic (methanolic and ethanolic) extracts, while mannitol, trehalose and arabinose were the main sugars found in the polysaccharidic (boiling water) extracts after hydrolysis. The individual compounds identified in the extracts were submitted to a screening of tumour cells growth inhibitory activity, but only the phenolic acids and a related compound, cinnamic acid, presented activity. This compound was found to be the most potent one regarding cell growth inhibition in the NCI-H460 cell line. The effect of the individual and combined treatment with the identified compounds was also evaluated. Cinnamic and protochatequic acids caused a statistically significantly reduction in the number of viable cells. In addition, p-hydroxybenzoic acid did not show any significantly reduction in the viable cell number. Nevertheless, it was verified that the concomitant use of the three compounds provided the strongest decrease in the viable cell number, suggesting a possible concomitant effect of those compounds. Overall, the present work has contributed to further understand the bioactive potential of wild edible mushrooms from the Northeast of Portugal. This study allowed to identify some species with antioxidant or tumour cell growth inhibitory potential.

The impact of gamma irradiation on the cytotoxic properties and phenolic composition of Thymus vulgaris L. and Menta x piperita L.

Irradiation has been increasingly recognized as an effective decontamination technique, also ensuring the chemical and organoleptic quality of medicinal and aromatic plants 1 . The use of medicinal plants in the prevention and or treatment of several diseases has revealed satisfactory results as anti-inflammatory, antimutagenic, anti-cancer and antioxidant agents 2 . The aim of the present study was to evaluate the effects of gamma irradiation on the cytotoxic properties and phenolic composition of Thymus vulgaris L. and Menta x piperita L. (methanolic extracts). Phenolic compounds were analyzed by HPLC-DAD-ESI MS, while the cytotoxicity of the samples was assessed in MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), HeLa (cervical carcinoma), HepG2 (hepatocellular carcinoma) cell lines, as also in non-tumor cells (PLP2). Thirteen and fourteen phenolic compounds were detected in T. vulgaris and M. piperita, respectively, but none of them was affected by the irradiation up to a dose of 10 kGy. However, despite there were no changes in the cytotoxic properties of irradiated peppermint samples in tumor cell lines, the thyme samples irradiated with 10 kGy showed higher cytotoxicity in comparison with the samples submitted to other doses (2 and 5 kGy). This highlights that 10 kGy can be a suitable dose to ensure the sanitary treatment, without modifying the bioactive composition and properties of these aromatic plants.

In vitro effects of erosive challenge on the surface properties of sealants

Aim: To assess in vitro the surface roughness (Ra), Vickers hardness (VHN) and surface morphology of resin and glass ionomer materials used for sealants after dynamic erosive challenge. Methods: Twenty specimens of each material were prepared and divided into experimental (erosive challenge) and control groups (n=10): Protect Riva (SDI), Opallis Flow (3M ESPE), Fluroshield (Dentsply), Filtek Z350 XT Flow (3M ESPE). The erosive challenge was performed 4 times per day (90 s) in cola drink and for 2 h in artificial saliva for 7 days. The control specimens were maintained in artificial saliva. Ra and VHN readings were performed before and after erosion. The percentage of hardness loss (%VHN) was obtained after erosion. The surface morphology was evaluated by scanning electron microscopy (SEM). The data were analyzed by ANOVA, Tukey and paired t tests (α=0.05). Results: After erosion and saliva immersion, there was an increase in Ra values for all groups and Riva group showed the highest Ra values. After erosive challenge, Riva and Filtek groups showed significant decrease in VHN values, but Filtek group showed the greatest %VHN. For all groups there was inorganic particle protrusion and matrix degradation after erosion visualized by SEM images. Conclusions: Erosive challenge affected the surface properties of all materials used as sealants, particularly in the Riva and Filtek groups.

Efeito da velocidade de aquecimento nas propriedades de produtos da cerâmica estrutural

Heating rate is one of the main variables that determine a fire cycle. In industrial processes that use high temperatures, greater fire great can reduce the cost of production and increase productivity. The use of faster and more efficient fire cycles has been little investigated by the structural ceramic industry in Brazil. However, one of the possibilities that aims at modernizing the sector is the use of roller kilns and the inclusion of natural gas as fuel. Thus, the purpose of this study is to investigate the effect of heating rate on the technological properties of structural ceramic products. Clay raw materials from the main ceramic industries in the state of Rio Grande do Norte were characterized. Some of the raw materials characterized were formulated to obtain the best physical and mechanical properties. Next, raw materials and formulations were selected to study the influence of heating rate on the final properties of the ceramic materials. The samples were shaped by pressing and extrusion and submitted to rates of 1 °C/min, 10 °C/min and 20 °C/min, with final temperatures of 850 °C, 950 °C and 1050 °C. Discontinuous cycles with rates of 10 °C/min or 15 °C/min up to 600 °C and a rate of 20 °C/min up to final temperature were also investigated. Technological properties were determined for all the samples and microstructural analysis was carried out under a number of fire conditions. Results indicate that faster and more efficient fire cycles than those currently in practice could be used, limiting only some clay doughs to certain fire conditions. The best results were obtained for the samples submitted to slow cycles up to 600 °C and fast fire sinterization up to 950 °C. This paper presents for the first time the use of a fast fire rate for raw materials and clay formulations and seeks to determine ideal dough and processing conditions for using shorter fire times, thus enabling the use of roller kilns and natural gas in structural ceramic industries

Influence of autogenous shrinkage on mass transport properties of concrete

La retracción autógena en el hormigón es el cambio volumétrico una vez iniciado su proceso de fraguado. Se desarrolla a edades muy tempranas debido a la retracción química y a la autodesecación. Éstos causan microfisuras en hormigones de alta resistencia y permiten el ingreso de agentes nocivos como dióxido de carbono, cloruros y sulfatos que deterioran al hormigón. A pesar de haber estudios de la retracción autógena, existe incertidumbre sobre su influencia en la durabilidad del hormigón. Por ello, el motivo del presente estudio es cuantificar y analizar el efecto de la retracción autógena en el hormigón usando tres pruebas de transporte: difusión de oxígeno, permeabilidad de oxígeno y absorción de agua. Dos métodos, para tres diferentes aglutinantes, fueron usados para determinar la mezcla control que produce menor retracción: utilizando SRA y realizando el curado en un cuarto de niebla. Posteriormente, los resultados de las pruebas de transporte entre la mezcla de control seleccionada y mezclas altamente afectadas por retracción autógena fueron comparados para diferentes aglutinantes. Resultados revelaron que muestras con SRA presentan menores retracciones autógenas y se sugiere que estas muestras sean consideradas de control. Se demostró que la retracción autógena afecta significativamente los coeficientes de transporte los cuales en un punto de vista de servicio pueden reducir la vida útil de cualquier estructura realizada con hormigón de alta resistencia. Esta investigación además confirmó que la mayor deformación autógena ocurre durante las dos primeras semanas; por lo tanto, se debe tomar cuidado suficiente en el curado.

Effect of Chemical Pretreatments on the Physical Properties of Kiwi

In this work the effect of pre-treatments on the physical properties of fresh kiwi was studied. For that, a set of tests using chemical pretreatments was used, in which the samples were subjected to aqueous solutions of ascorbic acid and potassium metabisulfite at concentrations of 0.25% and 1% (w/v) for periods of 30 and 60 minutes, in order to understand the implications of the treatments in the color and texture of the kiwi as compared to its original properties. The results showed that the kiwi treated with ascorbic acid changed its color very intensively when compared to the fresh product, and this trend was intensified after storage. Contrarily, when potassium metabisulfite was used, the changes in color were quite negligible right after the treatment and even lower after the storage period of 6 days under refrigeration. After the treatments with both solutions, the kiwi texture was drastically changed, diminishing hardness considerably and increasing elasticity for all treatments. The same could be observed after six days of refrigeration.

Influência da adição de resíduo de caulim nas propriedades tecnológicas de uma massa padrão de porcelanato produzido em escala industrial

VARELA, M. L. et al. Influência da adição de resíduo de caulim nas propriedades tecnológicas de uma massa padrão de porcelanato produzido em escala industrial. Cerâmica, v.55, n.334 p.209-215. 2009.ISSN 0366-6913.Disponível em: . Acesso em: 06 out. 2010.

Influência da adição de resíduo de caulim nas propriedades tecnológicas de uma massa padrão de porcelanato produzido em escala industrial

VARELA, M. L. et al. Influência da adição de resíduo de caulim nas propriedades tecnológicas de uma massa padrão de porcelanato produzido em escala industrial. Cerâmica, v.55, n.334 p.209-215. 2009.ISSN 0366-6913.Disponível em: . Acesso em: 06 out. 2010.

Influência da adição de resíduo de caulim nas propriedades tecnológicas de uma massa padrão de porcelanato produzido em escala industrial

VARELA, M. L. et al. Influência da adição de resíduo de caulim nas propriedades tecnológicas de uma massa padrão de porcelanato produzido em escala industrial. Cerâmica, v.55, n.334 p.209-215. 2009.ISSN 0366-6913.Disponível em: . Acesso em: 06 out. 2010.

Influence of field slope and coffee plantation age on the physical properties of a red-yellow Latosol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Adsorption of reactive dye on seawater-neutralised bauxite refinery residue

This investigation has demonstrated the need for thermal treatment of seawater neutralised red mud (SWRM) in order to obtain reasonable adsorption of Reactive Blue dye 19 (RB 19). Thermal treatment results in a greater surface area, which results in an increased adsorption capacity due to more available adsorption sites. Adsorption of RB 19 has been found to be best achieved in acidic conditions using SWNRM400 (heated to 400 �C) with an adsorption capacity of 416.7 mg/g compared to 250.0 mg/g for untreated SWNRM. Kinetic studies indicate a pseudosecond-order reaction mechanism is responsible for the adsorption of RB 19 using SWNRM, which indicates adsorption occurs by electrostatic interactions.

Rice husk biochar and crop residue amendment in subtropical cropping soils: Effect on biomass production, nitrogen use efficiency and greenhouse gas emissions

We investigated the effect of maize residues and rice husk biochar on biomass production, fertiliser nitrogen recovery (FNR) and nitrous oxide (N2O) emissions for three different subtropical cropping soils. Maize residues at two rates (0 and 10 t ha−1) combined with three rates (0, 15 and 30 t ha-1) of rice husk biochar were added to three soil types in a pot trial with maize plants. Soil N2O emissions were monitored with static chambers for 91 days. Isotopic 15N-labelled urea was applied to the treatments without added crop residues to measure the FNR. Crop residue incorporation significantly reduced N uptake in all treatments but did not affect overall FNR. Rice husk biochar amendment had no effect on plant growth and N uptake but significantly reduced N2O and carbon dioxide (CO2) emissions in two of the three soils. The incorporation of crop residues had a contrasting effect on soil N2O emissions depending on the mineral N status of the soil. The study shows that effects of crop residues depend on soil properties at the time of application. Adding crop residues with a high C/N ratio to soil can immobilise N in the soil profile and hence reduce N uptake and/or total biomass production. Crop residue incorporation can either stimulate or reduce N2O emissions depending on the mineral N content of the soil. Crop residues pyrolysed to biochar can potentially stabilise native soil C (negative priming) and reduce N2O emissions from cropping soils thus providing climate change mitigation potential beyond the biochar C storage in soils. Incorporation of crop residues as an approach to recycle organic materials and reduce synthetic N fertiliser use in agricultural production requires a thorough evaluation, both in terms of biomass production and greenhouse gas emissions.

Reactivity Of Silica From Rice Husk With Lime

The paper correlates the reactivity of rice husk ash with its physicochemical properties such as crystallinity, surface area, microstructure, particle size distribution, porosity and solubility. These properties, in tum, are dependent on the time-temperature conditions under which the ash is prepared. It is found that the reactivity of the ash cannot be quantified by any one of these parameters alone, though they all indicate it qualitatively. Therefore, a method for quantifying this property was developed, by which the Reactivity Index is obtained. There is only a gradual change in the reactivity index of RHA with ashing temperature, as in many other properties, like surface area, porosity and total volume of gas absorbed by unit mass of the silica ash. This reactive index is found to be useful in determining the optimum ash/lime ratios required to give the best performance for RHA-lime composites.