The inflammatory stimulus of a natural latex biomembrane improves healing in mice

The aim of the present study was to compare healing obtained with biomembranes with the natural healing process (sham) using biochemical and immunohistological assays. C57BL/6 mice were divided into 4 groups of 15 mice each and received different subcutaneous implants: natural latex biomembrane (NLB), denatured latex (DL), expanded polytetrafluorethylene (ePTFE), or sham. On the 2nd, 7th, and 14th days post-treatment, 5 mice per group were sacrificed and biopsied for the following measurements: oxidative stress based on malondialdehyde (MDA), myeloperoxidase (MPO) and hydrogen peroxide by the method of ferrous oxidation-xylenol orange (FOX), as well as glutathione and total proteins; histological evaluation to enumerate inflammatory cells, fibroblasts, blood vessels, and collagen, and immunohistochemical staining for inducible nitric oxide synthase, interleukin-1β, vascular endothelial growth factor (VEGF), and transforming growth factor-β1 (TGF-β1). On day 2 post-treatment, NLB stimulated a dense inflammatory infiltrate mainly consisting of polymorphonuclear cells, as indicated by increased MPO (P < 0.05), but oxidative stress due to MDA was not observed until the 7th day (P < 0.05). The number of blood vessels was greater in NLB (P < 0.05) and DL (P < 0.05) mice compared to sham animals on day 14. NLB induced fibroplasia by day 14 (P < 0.05) with low expression of TGF-β1 and collagenesis. Thus, NLB significantly induced the inflammatory phase of healing mediated by oxidative stress, which appeared to influence the subsequent phases such as angiogenesis (with low expression of VEGF) and fibroplasia (independent of TGF-β1) without influencing collagenesis.

Protective effects of organoselenium compounds against methylmercury-induced oxidative stress in mouse brain mitochondrial-enriched fractions

We evaluated the potential neuroprotective effect of 1-100 µM of four organoselenium compounds: diphenyl diselenide, 3’3-ditri-fluoromethyldiphenyl diselenide, p-methoxy-diphenyl diselenide, and p-chloro-diphenyl diselenide, against methylmercury-induced mitochondrial dysfunction and oxidative stress in mitochondrial-enriched fractions from adult Swiss mouse brain. Methylmercury (10-100 µM) significantly decreased mitochondrial activity, assessed by MTT reduction assay, in a dose-dependent manner, which occurred in parallel with increased glutathione oxidation, hydroperoxide formation (xylenol orange assay) and lipid peroxidation end-products (thiobarbituric acid reactive substances, TBARS). The co-incubation with diphenyl diselenide (100 µM) completely prevented the disruption of mitochondrial activity as well as the increase in TBARS levels caused by methylmercury. The compound 3’3-ditrifluoromethyldiphenyl diselenide provided a partial but significant protection against methylmercury-induced mitochondrial dysfunction (45.4 ± 5.8% inhibition of the methylmercury effect). Diphenyl diselenide showed a higher thiol peroxidase activity compared to the other three compounds. Catalase blocked methylmercury-induced TBARS, pointing to hydrogen peroxide as a vector during methylmercury toxicity in this model. This result also suggests that thiol peroxidase activity of organoselenium compounds accounts for their protective actions against methylmercury-induced oxidative stress. Our results show that diphenyl diselenide and potentially other organoselenium compounds may represent important molecules in the search for an improved therapy against the deleterious effects of methylmercury as well as other mercury compounds.

Improved biological performance of magnesium by micro-arc oxidation

Magnesium and its alloys have recently been used in the development of lightweight, biodegradable implant materials. However, the corrosion properties of magnesium limit its clinical application. The purpose of this study was to comprehensively evaluate the degradation behavior and biomechanical properties of magnesium materials treated with micro-arc oxidation (MAO), which is a new promising surface treatment for developing corrosion resistance in magnesium, and to provide a theoretical basis for its further optimization and clinical application. The degradation behavior of MAO-treated magnesium was studied systematically by immersion and electrochemical tests, and its biomechanical performance when exposed to simulated body fluids was evaluated by tensile tests. In addition, the cell toxicity of MAO-treated magnesium samples during the corrosion process was evaluated, and its biocompatibility was investigated under in vivo conditions. The results of this study showed that the oxide coating layers could elevate the corrosion potential of magnesium and reduce its degradation rate. In addition, the MAO-coated sample showed no cytotoxicity and more new bone was formed around it during in vivo degradation. MAO treatment could effectively enhance the corrosion resistance of the magnesium specimen and help to keep its original mechanical properties. The MAO-coated magnesium material had good cytocompatibility and biocompatibility. This technique has an advantage for developing novel implant materials and may potentially be used for future clinical applications.

Galactose oxidation using 13C in healthy and galactosemic children

Galactosemia is an inborn error of galactose metabolism that occurs mainly as the outcome of galactose-1-phosphate uridyltransferase (GALT) deficiency. The ability to assess galactose oxidation following administration of a galactose-labeled isotope (1-13C-galactose) allows the determination of galactose metabolism in a practical manner. We aimed to assess the level of galactose oxidation in both healthy and galactosemic Brazilian children. Twenty-one healthy children and seven children with galactosemia ranging from 1 to 7 years of age were studied. A breath test was used to quantitate 13CO2 enrichment in exhaled air before and at 30, 60, and 120 min after the oral administration of 7 mg/kg of an aqueous solution of 1-13C-galactose to all children. The molar ratios of 13CO2 and 12CO2 were quantified by the mass/charge ratio (m/z) of stable isotopes in each air sample by gas-isotope-ratio mass spectrometry. In sick children, the cumulative percentage of 13C from labeled galactose (CUMPCD) in the exhaled air ranged from 0.03% at 30 min to 1.67% at 120 min. In contrast, healthy subjects showed a much broader range in CUMPCD, with values from 0.4% at 30 min to 5.58% at 120 min. The study found a significant difference in galactose oxidation between children with and without galactosemia, demonstrating that the breath test is useful in discriminating children with GALT deficiencies.

Fat gain with physical detraining is correlated with increased glucose transport and oxidation in periepididymal white adipose tissue in rats

As it is a common observation that obesity tends to occur after discontinuation of exercise, we investigated how white adipocytes isolated from the periepididymal fat of animals with interrupted physical training transport and oxidize glucose, and whether these adaptations support the weight regain seen after 4 weeks of physical detraining. Male Wistar rats (45 days old, weighing 200 g) were divided into two groups (n=10): group D (detrained), trained for 8 weeks and detrained for 4 weeks; and group S (sedentary). The physical exercise was carried out on a treadmill for 60 min/day, 5 days/week for 8 weeks, at 50-60% of the maximum running capacity. After the training protocol, adipocytes isolated from the periepididymal adipose tissue were submitted to glucose uptake and oxidation tests. Adipocytes from detrained animals increased their glucose uptake capacity by 18.5% compared with those from sedentary animals (P<0.05). The same cells also showed a greater glucose oxidation capacity in response to insulin stimulation (34.55%) compared with those from the S group (P<0.05). We hypothesize that, owing to the more intense glucose entrance into adipose cells from detrained rats, more substrate became available for triacylglycerol synthesis. Furthermore, this increased glucose oxidation rate allowed an increase in energy supply for triacylglycerol synthesis. Thus, physical detraining might play a role as a possible obesogenic factor for increasing glucose uptake and oxidation by adipocytes.

STABILITY OF OILS HEATED BY MICROWAVE: UV - SPECTROPHOTOMETRIC EVALUATION

The effects of microwave heating on the oxidative stability of refined canola, corn and soybean oils were determined by absorptivity in the UV spectrum and by chemical analysis (peroxide and acid values). Samples were heated in a microwave oven (800 W, 2,450 MHz) for 0 to 36 min. Microwave heating produced oxidative degradation in the three oils. Absorptivity at 232 and 270 nm increased gradually with an increase in microwave exposure time (0-36 min) for canola, corn and soybean oils. Values of absorptivity at 232 nm increased from 4.812, 3.568 and 4.183 to 10.579, 12.874 and 15.950 after 36 min of heating canola, corn and soybean oil, respectively. The absorptivity at 232nm, due to the formation of conjugated dienes, was a good index for measuring the degradation of microwaved samples. UV scanning (220 - 320 nm) detected alterations in the spectrum of microwaved samples. Acid value also increased within 36 min of heating for all oils. Peroxide value showed a significant difference (P<0.05) in the initial stage of heating (0-6 min) for all oils. After this period it could not be correlated with absorptivity at 232 nm, due to the instability of hydroperoxides at high temperatures.

Determining economical TBHQ doses for corn oil stability

Corn oil obtained from a Brazilian industry, free from antioxidants and citric acid, added of different tertiary butylhydroquinone (TBHQ) concentrations, was submitted to accelerated oxidation in the Schaal oven test at 63°C for 120 hours and for 168 hours in a photooxidation chamber. Peroxide and absorptivity values at 232nm and 270nm were determined for this oil. From the Schaal oven test results, the best and the economical TBHQ doses were determined to this oil. Afterwards, a shelf life experiment was conducted and confirmed 115mg.kg-1 TBHQ as the best and economical dose for that oil.

Oat hulls treated with alkaline hydrogen peroxide associated with extrusion as fiber source in cookies

Cookies were prepared with the replacement of 20% of wheat flour by chemically (alkaline hydrogen peroxide) and physically (extrusion) treated oat hulls, with the objective to investigate the possibility of use of this modified material. Cookies elaborated with the untreated hulls were used as control. Cookies were evaluated for their physical (spread ratio, specific volume and color) and sensory characteristics, and no difference was detected (p<0.05) among the cookies in relation to the physical properties. Triangule test, used to verify difference (p<0.05) among treated and untreated cookies, confirmed the efficiency of the treatment in sensory level. The acceptance level of cookies with treated fiber was evaluated by potential consumers of the product, obtaining 91% acceptance. The cookies presented 10.6 g of dietary fiber per 100 g of product.

Lignin oxidation by PCD technology

The purpose of this study is to investigate whether commercial Kraft lignin can be treated with pulsed corona discharge apparatus so that it becomes active. Active lignin refers to the kind of lignin that can be precipitated on the surface of a fiber by lowering the pH. A secondary agenda here is to remove the pungent smell of kraft lignin, which is caused by organically bound sulfur. It is expected that the study will identify mild processing conditions and parameters for achievement of the desired outcome. In the literature review, the properties of lignin are explained, as is their impact on any further processing. In addition, a number of processes are described for the oxidation of lignin in a variety of applications. In the experimental part of the study, test runs were conducted to determine the effects of oxygen supply and pulse frequency on oxidation results, where the purpose is to produce reactive lignin and to find a process that is feasible at an industrial scale. Based on the reported experiments, lignin could not be made active or precipitated to the surface of the fiber. Actual changes in the structure of lignin were not observed, but the pungent smell of lignin was removed. The exact reason for this change could not be established because sulfur NMR analysis did not work for the lignin samples.

Evaluation of the quality of pet foods using fast techniques and official methods

This paper was designed to evaluate the rancidity of 18 pet food samples using the Diamed FATS kits and official AOCS methods for the quantification of free fatty acids, peroxide value and concentrations of malonaldehyde and alkenal in the lipid extracted. Although expiration dates have passed, the samples presented good quality evidencing little oxidative rancidity. The results of this study suggest that the Brazilian pet food market is replete with products of excellent quality due to the competitiveness of this market sector.

Microorganisms screening for limonene oxidation

Limonene is a monoterpene obtained in large amounts from essential oils and is used as a raw material for the synthesis of flavors and fine chemicals. Several pathways or routes for the microbial degradation of limonene making use of the cytochrome P450-dependent monooxygenases have been described. In this study, we present a fermentative screening of microorganisms in order to verify their ability to perform the desirable conversion. In parallel, the PCR technique was used to select the microorganisms that contain the limC gene, which is responsible for the conversion of carveol to carvone. The microorganisms selected by PCR were not able to bioconvert limonene. From this result, we can suppose that these strains do not have the gene that codifies the enzyme responsible for the transformation of limonene into carveol. The results obtained in the fermentative screening showed that 4 microorganisms were able to bioconvert limonene into carveol. In addition, the amplification results showed the presence of fragments of 800 pb, expected for the limC gene. Therefore, the results obtained in the bioconversion and evaluation of the limC gene did not allow a correlation showing that these strains do not contain all the enzymes responsible for the conversion of limonene to carvone.

The influence of achyrocline satureioides ("Marcela") extract on the lipid oxidation of salami

The effect of two levels (0.5 and 1%) of hydroalcoholic extract of Achyrocline satureioides on the safety (TBARS values) and quality (pH, water activity, colour, weight loss, and sensorial attributes) of salami was evaluated. The addition of Achyrocline satureioides extract decreased TBARS values significantly during the storage of salami when compared to the control, which was elaborated without Achyrocline satureioides extract. The treatment with 1% of "Marcela" extract showed larger lipid stability than that of the lot with 0.5%, However, it presented a decrease (p < 0.05) in the sensorial acceptance. The two levels of "Marcela" extract did not influence pH, water activity, colour, and weight loss significantly. This study indicates that the hydroalcoholic extract of "Marcela" was effective in decreasing the lipid oxidation and at 0.5% it did not alter the sensorial features; therefore, it may be used in salami to provide safer products for the consumers.

Antioxidant activity of essential oil from Coriandrum Sativum L. in Italian salami

Four formulations of Italian salami type were produced: without antioxidants; with essential oil of coriander essential oil (0.01%); with BHT (0.01%); and with Coriander essential oil and BHT (0.005 and 0.005%). The antioxidant activity of salamis was evaluated by the lipid oxidation, through the techniques of peroxide number and TBARS. The salami with the coriander essential oil exhibited reduction in lipid oxidation by increasing the shelf life of the product. The salami with the coriander essential oil and BHT showed no synergism between the antioxidants. The salami using BHT presented less antioxidant activity than that of the salami using coriander essential oil.

Lipid and protein oxidation in the internal part of italian type salami containing basil essential oil (Ocimum basilicum L.)

Different concentrations of basil essential oil (Ocimum basilicum L.) (0.19; 0.38; 0.75; 1.87; 3.75 and 6.00 mg.g-1) were evaluated in relation to their antioxidant activity using the DPPH● radical methodology. From the IC50 obtained data, the concentrations of 0.19; 0.38; 0.75; 1.87; 3.75; 6.00 and 12.00 mg.mL-1 were applied directly to the product and these were sensorially evaluated by the test of control difference. The concentrations related to the highest acceptability (0.19; 0.38 and 0.75 mg.g-1) were tested for antioxidant activity in the internal part of Italian type salami - during the processing and after 30 days of storage, in terms of lipid and protein oxidation. The oxidation of lipids was determined using the method of TBARS. The method of carbonyl compounds was employed for proteins oxidation. Five different formulations of salami were elaborated: blank (without the use of antioxidant); control (using sodium eritorbate as antioxidant); and adding 0.19; 0.38 and 0.75 mg.g-1 of basil essential oil. The product was kept between 25 ºC and 18 ºC and UR between 95% and 70%, for 28 days. Analyses were carried out on the processing day and after 2, 7, 14, 21 and 28 days, and also following 30 days of storage. The basil essential oil in vitro presented an antioxidant activity of IC50 12 mg.mL-1. In the internal part of the Italian type salami the commercial antioxidant (control) and the formulation containing 0.75 mg.g-1 of basil essential oil presented antioxidant activity in relation to the lipids, but not to the proteins - during processing and storage.

Phenolic compounds and antioxidant activity in fermented rice (Oryza sativa) bran

This study investigated the content of total phenolic compounds and antioxidant activity in fermented rice bran in order to evaluate the effect of solid state fermentation on these properties. The process was performed with the fungus Rhizopus oryzae CTT 1217 in tray reactors at 30 °C for 120 hours. Samples of fermented rice bran were collected every 24 hours. Antioxidant property was evaluated by the diphenyl-1-picrylhydrazyl radical scavenging method and through the inhibition of enzymatic oxidation and lipid peroxidation of olive oil. The methanol extract of the biomass obtained at 96 hours of fermentation inactivated 50% of free radical in 15 minutes. The same extract reduced the peroxide value in the olive oil by 57% after 30 days of storage. The aqueous extract of the biomass obtained at 120 hours was the most efficient inhibitor of the darkening reaction catalyzed by peroxidase.