988 resultados para nitrogen-free extract


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Most studies on the antioxidants, lipoic acid (LA) and ascorbic acid (AA), focused on species that, unlike teleost fish, are not scurvy-prone, and are able to synthesize AA. The antioxidant properties of LA may make it useful in aquaculture nutrition, but several effects must first be investigated, and we address here plasma free amino acids (FAA). In mammals, LA and AA in high doses were claimed to alter plasma FAA profile; to our knowledge, however, no data are available in fish. We therefore studied the effects of dietary LA and AA on plasma FAA in the South American teleost fish pacu, which is being used increasingly in aquaculture. LA treatment decreased concentrations of 18 of 23 individual FAA; specifically, dispensable and total FAA were significantly affected. Ornithine was elevated (+26%) in LA-treated fish and significantly decreased ratios of plasma [Arg]/[Orn] and other individual [FAA]/[Orn] were observed. LA and AA both affected sulfur FAA concentrations. Plasma cystine levels were significantly increased in the LA-supplemented groups. AA had little effect on most amino acids, and no interaction with LA was detected. AA supplementation did, however, significantly lower taurine (-42%) and cystathionine (-31%) levels in plasma. No effect on the branched chain:aromatic amino acid ratios was observed. The data indicate that at the dietary level studied, LA and AA independently affect selected plasma FAA in pacu, and suggest that any use of LA in particular as a dietary supplement should take into account an altered plasma FAA profile.

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Reactive oxygen species (ROS) and free radical species have been implicated in initiating, accompanying or causing many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Maytenus species have long been used, in several countries, as traditional medicines against gastric ulcers, dyspepsia and others gastric problems and for their anti-inflammatory properties. In this study, Maytenus aquifolium (Celastraceae) root bark ethanol extract was assessed for its ability to scavenge free radicals and reactive oxygen species. The results were expressed as percentage inhibition of the active species. The extract was efficient against studied reactive species: DPPH radical (obtained inhibition = 35.5 ± 1.3 %), ABTS.+ (IC50 = 0.0036 ± 0.0003 mg/mL), HOCl (IC50 = 0.002 ± 0.0001 mg/mL), O2 .- (obtained inhibition = 36.0 ± 2.1 %), and NO. (obtained inhibition = 18.3 ± 0.4 %). Uniterms Oxidant species Free radicals Maytenus aquifolium Oxidative damage.

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Purpose: The objective of this study was to evaluate the antimicrobial activity of six toothpastes for infants: 3 fluoride-free experimental toothpastes - cashew-based, mango-based and without plant extract and fluoride compared with 2 commercially fluoride-free toothpastes and 1 fluoridated toothpastes. Methods: Six toothpastes for infants were evaluated in this study: (1) experimental cashew-based toothpaste; (2) experimental mango-based toothpaste; (3) experimental toothpaste without plant extract and fluoride (negative control); (4) First Teeth brand toothpaste; (5) Weleda brand toothpaste; and (6) Tandy brand toothpaste (positive control). The antimicrobial activity was recorded against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus, and Candida albicans using the agar plate diffusion test. Results: First Teeth, Weleda, mango-based toothpaste, and toothpaste without plant extract presented no antimicrobial effect against any of the tested micro-organisms. Cashew toothpaste had antimicrobial activity against S mutans, S sobrinus, and L acidophilus, but it showed no antimicrobial activity against C albicans. There was no statistical difference between the inhibition halo of cashew and Tandy toothpastes against S mutans and L acidophilus. Conclusions: Cashew fluoride-free toothpaste had inhibitory activity against Streptococcus mutans and Lactobacillus acidophilus, and these results were similar to those obtained for fluoridated toothpaste.

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This study examined the antioxidant activity of lyophilized rosemary extract added to soybean oil, subjected to thermoxidation conditions and also its synergistic effect with the synthetic antioxidant tertiary butylhydroquinone (TBHQ). Soybean oil samples with no antioxidant added (SO), 3,000mg/kg rosemary extract (RE), 50mg/kg TBHQ (TBHQ), and a mixture of those two antioxidants (RE+TBHQ) were heated to 180C for 20h. After 0, 10 and 20h, the oxidative stability, total polar compounds, tocopherol content and fatty acid profile were determined. The addition of rosemary extract increased oxidative stability and resulted in a lower formation of total polar compounds and a higher retention of tocopherols. The RE treatment showed the highest amount of polyunsaturated fatty acids after 20h. There was not any synergy between TBHQ and rosemary extract in preventing oxidation of soybean oil. Rosemary extract showed a higher antioxidant potential when compared with TBHQ. PRACTICAL APPLICATIONS: Antioxidants are important ingredients in food processing because they have the capacity to protect foods, containing oils and fats, from damage caused by free radicals and reactive oxygen species. Synthetic antioxidants are widely used in the food industry; however, their utilization has been questioned because of toxicity. Therefore, there is a growing interest in the use of natural antioxidants to reduce or replace the synthetic antioxidants. Several species are used in cooking, medicine and by the pharmaceutical industry, standing out the rosemary. Being rich in compounds with high antioxidant activity, the rosemary extract can be used to replace synthetic antioxidants used in vegetable oils. © 2012 Wiley Periodicals, Inc.

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Microorganisms can produce lipases with different biochemical characteristics making necessary the screening of new lipase-producing strains for different industrial applications. In this study, 90 microbial strains were screened as potential lipase producers using a sensitive agar plate method with a suitable medium supplemented with Tween 20 and also a liquid culture supplemented with olive oil. The highest cell growth and lipase production for Candida viswanathii were observed in triolein and oleic acid when used as the only pure carbon source. Renewable low-cost triacylglycerols supported the best cell growth, and olive oil was found to be the best inducer for lipase production (19.50 g/L and 58.50 U). The selected conditions for enzyme production were found with yeast extract as nitrogen source and 1.5 % (w/v) olive oil (85.70 U) that resulted in a good cell growth yield (YX/S = 1.234 g/g) and lipase productivity (1.204 U/h) after 72 h of shake-flask cultivation. C. viswanathii lipase presented high hydrolytic activity on esters bonds of triacylglycerols of long-chain, and this strain can be considered an important candidate for future applications in chemical industries. © 2012 Springer-Verlag Berlin Heidelberg and the University of Milan.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Purpose: The purpose of this paper is to evaluate the antioxidant activity of ginger ethanol extract in soybean oil under thermoxidation. Design/methodology/approach: A total of four treatments were used: soybean oil free of synthetic antioxidants, soybean oil containing 2,500 mg/kg of ginger extract, soybean oil containing 50 mg/kg of TBHQ, soybean oil containing the mixture of natural extract, and TBHQ in the before-cited concentration. The treatments were discontinuously submitted to plates heated at 180°C, for 20 hours. Samples were removed in the times of 0, 4, 8, 12, 16 and 20 hours of heating and they were analyzed as to their oxidative stability, total polar compounds, peroxide and conjugated diene values. Findings: The results showed the efficiency of the ginger extract in protecting the oil against lipid oxidation. It could be concluded that ginger extract might be indicated as an additive that acts against lipid oxidation and, consequently, increases shelf life of food. Practical implications: These studies may prove to be beneficial to the exploitation of natural antioxidant sources for the preservation and/or extension of raw and processed food shelf life. Therefore, they could also be applied in the area of pharmaceuticals for the protection of human life. Originality/value: This study offers information on the use of natural antioxidants as an alternative to the use of synthetic antioxidants, which might be considered toxic. © Emerald Group Publishing Limited.

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Ethnopharmacological relevance: Psidium cattleianum Sabine is extensively used in Brazilian traditional medicine to treat several diseases including painful disorders. Aim of the study to investigate the toxicity and the possible analgesic activities of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine (ELPCS), to support its use in folk medicine. To screen the major phytochemical constituents of this extract and evaluate their antioxidant activity. Materials and methods: ELPCS was assessed for its antioxidant activity using the DPPH model. Its analgesic activity was examined using mouse models of acetic acid-induced writhing and hot plate paw licking models. The major phytochemical constituents of the extract were screened; their toxicity on LLC-MK2 mammalian cells was evaluated. Results: ELPCS exhibited significant peripheral analgesic activity at doses of 60, 80, 100, 200 and 400 mg/kg in mice, but it did not display central analgesic activity and not was toxic to LLC-MK2 cell (LD 50>400 μg/mL). The extract exhibited free radical scavenging activity as evidenced by IC 50 values (15.9 μg/mL) obtained by the DPPH method. Phytochemical screening detected flavonoids, saponins, cardiac glycosides, anthraquinones, and tannins. Conclusions: The results of the experimental studies proved the analgesic activity of ELPCS and supported the traditional use of this plant. © 2013 Elsevier B.V. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pseudomonas oleovorans were grown on sugary cassava extracts supplemented with andiroba oil for the synthesis of a mediumchain- length polyhydroxyalkanoate (PHAMCL). The concentration of total sugars in the extract was approximately: 40 g/L in culture 1, 15 g/L in cultures 2 and 3, and 10 g/L in culture 4. Supplementation with 1% andiroba oil and 0.2 g/L of (NH4)2HPO4 was performed 6.5 hours after growth in culture 3, and supplementation with the same amount of andiroba oil and 2.4 g/L of (NH4)2HPO4 was performed at the beginning of growth in culture 4. The synthesis resulted mainly in 3-hydroxy-decanoate and 3-hydroxy-dodecanoate units; 3-hydroxy-butyrate, 3-hydroxy-hexanoate; and 3-hydroxy-octanoate monomers were also produced but in smaller proportions. P. oleovorans significantly accumulated PHAMCL in the deceleration phase of growth with an oxygen limitation but with sufficient nitrogen concentration to maintain cell growth. The sugary cassava extract supplemented with andiroba oil proved to be a potential substrate for PHAMCL production.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Although the exact cause of neuronal loss in Parkinson's disease is not known, evidence points to oxidative stress and the production of reactive oxygen species as the main events that occur in the substantia nigra pars compacta of the brain of parkinsonians. EGb761 is an extract of the leaves from the Ginkgo biloba tree that has been reported as an antioxidant and neuroprotective agent. The objective of this work was to perform a systematic review of the studies that analysed the effect of Ginkgo biloba extract on Parkinson's disease or Parkinsonism. This research was conducted using the following databases: Medline, PsycInfo, Cinahl, Sigle, Lilacs, Scielo, Cochrane Library, and Embase. Initially, we selected 32 articles. After a more detailed analysis, only 10 articles remained. One of the hypotheses for the positive effect of EGb761 on Parkinson's disease is the reduction or inhibition of monoamine-oxidase activity. This enzyme metabolises dopamine, inducing the formation of free radicals, which in turn damage nigrostriatal neurons. Another hypothesis is that the neuroprotective effect of EGb761 against 6-hydroxydopamine, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and MPP+ toxins. As there are few studies on the effect of EGb761 on humans, this review could contribute new data to further the discussion of this issue.

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The study of allelopathic activity has been aim of research that evaluates mainly species used in green fertilization. Raphanus sativus L. stands out among these species, because it shows high capacity for nutrient recycling, specially nitrogen and phosphorus, what makes it an advantageous cover plant in crop rotation systems. Considering the exposed, the present study had as objective the evaluation of the allelopathic and phytotoxic potentials of different concentrations of the R. sativus leaves ethanolic extract by mean of seeds germination analyses and development of lettuce seedlings, evaluating the phytotoxicity by determination of the mitotic index of lettuce root cells, realizing the phytochemical profile and investigating the antioxidant activity. It was possible to verify that the R. sativus extract interferes in the germination index, decreasing the germinability (5 mg. mL(-1) = 9.84%; 10 mg. mL(-1) = 11.91% and 20 mg. mL(-1)= 57.51%). In the lettuce seedlings growth, the extract of this species affected the roots and hypocotyls growth. It was possible to observe phenols and total flavonoids in the extract for the concentration of 1000 mu g. mL(-1)(161mg and 83.57 mg, respectively). It was also observed, higher antioxidant activity for the concentration of 1000 mu g. mL(-1) (89.76%). In the phytotoxicity assay was observed a dose dependent effect in the mitotic index and in the cellular events during cellular division. In this study it was possible to conclude that this species has allelochemical compounds which are able to interfere directly on the stabilization and development of other species.