952 resultados para Antioxidant activity index
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Objective. To evaluate the efficacy of a 3-month exercise training program in counteracting the chronotropic incompetence and delayed heart rate recovery in patients with systemic lupus erythematosus (SLE). Methods. A 12-week randomized trial was conducted. Twenty-four inactive SLE patients were randomly assigned into 2 groups: trained (T; n = 15, 3-month exercise program) and nontrained (NT; n = 13). A sex-, body mass index-, and age-matched healthy control (C) group (n = 8) also underwent the exercise program. Subjects were assessed at baseline and at 12 weeks after training. Main measurements included the chronotropic reserve (CR) and the heart rate (HR) recovery (Delta HRR) as defined by the difference between HR at peak exercise and at both the first (Delta HRR1) and second (Delta HRR2) minutes after the exercise test. Results. Neither the NT SLE patients nor the C group presented any change in the CR or in Delta HRR1 and Delta HRR2 (P > 0.05). The exercise training program was effective in promoting significant increases in CR (P = 0.007, effect size [ES] 1.15) and in Delta HRR1 and Delta HRR2 (P = 0.009, ES 1.12 and P = 0.002, ES 1.11, respectively) in the SLE T group when compared with the NT group. Moreover, the HR response in SLE patients after training achieved parameters comparable to the C group, as evidenced by the analysis of variance and by the Z score analysis (P > 0.05, T versus C). Systemic Lupus Erythematosus Disease Activity Index scores remained stable throughout the study. Conclusion. A 3-month exercise training program was safe and capable of reducing the chronotropic incompetence and the delayed Delta HRR observed in physically inactive SLE patients.
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Bucioli, SA, de Abreu, LC, Valenti, VE, and Vannucchi, H. Carnitine supplementation effects on nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress. J Strength Cond Res 26(6): 1695-1700, 2012-Previous studies have demonstrated that exercise stress increases oxidative stress in rats. However, antioxidant supplement therapy effects on reactive oxygen substances are conflicting. We evaluated the effects of carnitine on renal nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress. Wistar rats were divided into 3 groups: (a) control group (not submitted to exercise stress), (b) exercise stress group, and (c) exercise stress and carnitine group. The rats from group 3 were treated with gavage administration of 1 ml of carnitine (5 mg.kg(-1)) for 7 consecutive days. The animals from groups 2 and 3 were submitted to a bout of swimming exhaustive exercise stress. Kidney samples were analyzed for reactive substances to thiobarbituric acid by malondialdehyde (MDA), reduced glutathione (GSH), and vitamin-E levels. Carnitine treatment attenuated MDA increase caused by exercise stress (1:0.16 +/- 0.02 vs. 2:0.34 +/- 0.07 vs. 3:0.1 +/- 0.01 mmmol per milligram of protein; p < 0.0001). It also increased the renal levels of GSH (1:23 +/- 4 vs. 2:23 +/- 2 vs. 3:58 +/- 9 mu mol per gram of protein; p, 0.0001); however, it did not change renal vitamin E (1:24 +/- 5 vs. 2:27 +/- 1 vs. 3:28 +/- 5 mu M per gram of tissue; p < 0.001). In conclusion, carnitine improved oxidative stress and partially improved the nonenzymatic antioxidant activity in young rats submitted to exhaustive exercise stress.
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The present study aimed to evaluate the photoprotective effects of cosmetic formulations containing a dispersion of liposome with magnesium ascorbyl phosphate (MAP), alpha-lipoic acid (ALA) and kinetin, as well as their effects on the hydration and viscoelastic skin properties. The photoprotection was determined in vitro (antioxidant activity) and in vivo on UV-irradiated hairless mouse skin. The hydration effects were performed with the application of the formulations under study on the forearm of human volunteers and skin conditions were analyzed before and after a single application and daily applications during 4 weeks in terms of transepidermal water loss (TEWL), skin moisture and viscoelastic properties. The raw material under study possessed free-radical scavenging activity and the formulation with it protected hairless mouse skin barrier function against UV damage. After 4 weeks of application on human skin, the formulation under study enhanced stratum corneum skin moisture and also showed hydration effects in deeper layers of the skin. Thus, it can be concluded that the cosmetic formulation containing a dispersion of liposome with MAP, ALA and kinetin under study showed photoprotective effects in skin barrier function as well as pronounced hydration effects on human skin, which suggests that this dispersion has potential antiaging effects.
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An increasing number of women have been diagnosed with spondyloarthritis (SpA) in recent decades. While a few studies have analyzed gender as a prognostic factor of the disease, no studies have addressed this matter with a large number of patients in South America, which is a peculiar region due to its genetic heterogeneity. The aim of the present study was to analyze the influence of gender on disease patterns in a large cohort of Brazilian patients with SpA. A prospective study was carried out involving 1,505 patients [1,090 males (72.4%) and 415 females (27.6%)] classified as SpA according to the European Spondyloarthropaties Study Group criteria who attended at 29 reference centers for rheumatology in Brazil. Clinical and demographic variables were recorded and the following disease indices were administered: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Radiologic Index (BASRI), Maastricht Ankylosing Spondylitis Enthesitis Score (MASES), and Ankylosing Spondylitis Quality of Life (ASQoL). Ankylosing spondylitis (AS) was the most frequent disease in the group (65.4%), followed by psoriatic arthritis (18.4%), undifferentiated SpA (6.7%), reactive arthritis (3.3%), arthritis associated to inflammatory bowel disease (3.2%), and juvenile SpA (2.9%). The male-to-female ratio was 2.6:1 for the whole group and 3.6:1 for AS. The females were older (p<0.001) and reported shorter disease duration (p=0.002) than the male patients. The female gender was positively associated to peripheral SpA (p<0.001), upper limb arthritis (p<0.001), dactylitis (p=0.011), psoriasis (p<0.001), nail involvement (p<0.001), and family history of SpA (p=0.045) and negatively associated to pure axial involvement (p< 0.001), lumbar inflammatory pain (p=0.042), radiographic sacroiliitis (p<0.001), and positive HLA-B27 (p=0.001). The number of painful (p<0.001) and swollen (p=0.006) joints was significantly higher in the female gender, who also achieved higher BASDAI (p<0.001), BASFI (p=0.073, trend), MASES (p=0.019), ASQoL (p=0.014), and patient's global assessment (p=0.003) scores, whereas the use of nonsteroidal anti-inflammatory drugs (p<0.001) and biological agents (p=0.003) was less frequent in the female gender. Moreover, BASRI values were significantly lower in females (p<0.001). The female gender comprised one third of SpA patients in this large cohort and exhibited more significant peripheral involvement and less functional disability, despite higher values in disease indices.
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Cu(II)/neocuproine (2,9-dimethyl-1,10-phenanthroline) complexes were utilized for spectrophotometric determination of total polyphenol content in beers. This procedure is based on the reduction of Cu(II) by polyphenols in hydroethanolic medium (pH 7.0) in the presence of neocuproine, yielding Cu(I)/complexes with maximum absorption at 454 nm. The sensitivity of the proposed method was compared with the AOAC method using tannic and gallic acid as standards. The average apparent molar absorptivity, in L cm(-1) mol(-1), of tannic acid (3.50 +/- 0.20) x 10(5) and gallic acid (5.12 +/- 0.21) x 10(4), was twice as high for the proposed method. A lower limit of detection (LOD) (2.9 x 10(-1) mg L-1) was found when tannic acid was used in the proposed method. Additionally, less interference from the most common additives in beers was noticed. Total content of polyphenols was analyzed in 17 Brazilian samples. Results ranged from 35.5 to 556 mg L-1 of tannic acid, with higher values for recovery rates (45.4-118%, mean 85.0%) than for gallic acid. Although tannic acid is a mixture of polygalloyl glucoses, the total polyphenol content found in the samples suggests that tannic acid should be used as a standard. This is the first attempt to use this particular copper complex to quantify total polyphenol content in beer samples. (C) 2012 Elsevier Inc. All rights reserved.
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This study aimed to investigate the effects of pectinase enzyme treatment of acai pulp on cross-flow microfiltration (CFMF) performance and on phytochemical and functional characteristics of their compounds. Analyses of fouling mechanisms were carried out through resistance in series and blocking in law models. The enzymatic treatment was conducted using Ultrazym(R) AFPL (Novozymes A/S) at 500 mg kg(-1) of acai pulp for 30 min at 35 degrees C. Before microfiltrations, untreated and enzyme-treated acai pulps were previously diluted in distilled water (1:3; w/v). CFMFs were conducted using commercial alpha-alumina (alpha-Al2O3) ceramic membranes (Andritz AG, Austria) of 0.2 mu m and 0.8 mu m pore sizes, and 0.0047 m(2) of filtration area. The microfiltration unit was operated in batch mode for 120 min at 25 degrees C and the fluid-dynamic conditions were transmembrane pressure of Delta P = 100 kPa and cross-flow velocity of 3 m s(-1) in turbulent flow. The highest values of permeate flux and accumulated permeate volume were obtained using enzyme-treated pulp and 0.2 mu m pore size membranes with steady flux values exceeding 100 L h(-1) m(-2). For the 0.8 mu m pore size membrane, the estimated total resistance after the microfiltration of enzyme-treated acai pulp was 21% lower than the untreated pulp, and for the 0.2 mu m pore size membrane, it was 18%. Cake filtration was the dominant mechanism in the early stages of most of the CFMF processes. After approximately 20 min, however, intermediate pore blocking and complete pore blocking contributed to the overall fouling mechanisms. The reduction of the antioxidant capacity of the permeates obtained after microfiltration of the enzyme-treated pulp was higher (p < 0.01) than that obtained using untreated pulp. For total polyphenols, on the contrary, the permeates obtained after microfiltration of the enzyme-treated pulp showed a lower mean reduction (p < 0.01) than those from the untreated pulp. The results show that the enzymatic treatment had a positive effect on the CFMF process of acai pulp. (C) 2012 Elsevier Ltd. All rights reserved.
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The objective of this work was (1) to develop a dehydrated pepper with 45% humidity, determining the drying curves for pepper, with and without osmotic pre-treatment and (2) to evaluate the influence of both drying and osmotic treatment on the content ascorbic acid (vitamin C) in fresh pepper and pepper with 45% humidity. The experiments were carried out using the peppers cut in half, with and without osmotic pre-treatment, followed by drying in an oven at 70 degrees C. The results showed that the osmotic pretreatment did not influence the retention of ascorbic acid during the drying of pepper. The sensory analysis regarding the color, flavor, and texture attributes revealed that there was no difference in the acceptability.
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The objective of this study was to investigate whether differences in diet and in single-nucleotide polymorphisms (SNPs) found in paraoxonase-1 (PON-1), 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), cholesterol ester transfer protein (CETP) and apolipoprotein E (APOE) genes, are associated with oxidative stress biomarkers and consequently with susceptibility of low-density cholesterol (LDL) to oxidation. A multivariate approach was applied to a group of 55 patients according to three biomarkers: plasma antioxidant activity, malondialdehyde and oxidized LDL (oxLDL) concentrations. Individuals classified in Cluster III showed the worst prognoses in terms of antioxidant activity and oxidative status. Individuals classified in Cluster I presented the lowest oxidative status, while individuals grouped in Cluster II presented the highest levels of antioxidant activity. No difference in nutrient intake was observed among the clusters. Significantly higher gamma- and delta-tocopherol concentrations were observed in those individuals with the highest levels of antioxidant activity. No single linear regression was statistically significant, suggesting that mutant alleles of the SNPs selected did not contribute to the differences observed in oxidative stress response. Although not statistically significant, the p value of the APO E coefficient for oxLDL response was 0.096, indicating that patients who carry the TT allele of the APO E gene tend to present lower plasma oxLDL concentrations. Therefore, the differences in oxidative stress levels observed in this study could not be attributed to diet or to the variant alleles of PON-1, CETP, HMGCR or APO E. This data supports the influence of gamma-tocopherol and delta-tocopherol on antioxidant activity, and highlights the need for further studies investigating APO E alleles and LDL oxidation.
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Byrsonima crassa Niedenzu (Malpighiaceae) is used in Brazilian folk medicine for the treatment of diseases related mainly to gastric ulcers. In a previous study, our group described the gastric protective effect of the methanolic extract from the leaves of B. crassa. The present study was carried out to investigate the effects of methanolic extract and its phenolic compounds on the respiratory burst of neutrophils stimulated by H. pylori using a luminol-based chemiluminescence assay as well as their anti-H. pylori activity. The suppressive activity on oxidative burst of H. pylori-stimulated neutrophils was in the order of methyl gallate > (+)-catechin > methanol extract > quercetin 3-O-alpha-L-arabinopyranoside > quercetin 3-O-beta-D-galactopyranoside > amentoflavone. Methyl gallate, compound that induced the highest suppressive activity with IC50 value of 3.4 mu g/mL, did not show anti-H. pylori activity. B. crassa could be considered as a potential source of natural antioxidant in gastric ulcers by attenuating the effects on the damage to gastric mucosa caused by neutrophil generated reactive oxygen species, even when H. pylori displays its evasion mechanisms.
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Cisplatin is a highly effective chemotherapeutic drug; however, its use is limited by nephrotoxicity. Studies showed that the renal injury produced by cisplatin involves oxidative stress and cell death mediated by apoptosis and necrosis in proximal tubular cells. The use of antioxidants to decrease cisplatin-induced renal cell death was suggested as a potential therapeutic measure. In this study the possible protective effects of carvedilol, a beta blocker with antioxidant activity, was examined against cisplatin-induced apoptosis in HK-2 human kidney proximal tubular cells. The mitochondrial events involved in this protection were also investigated. Four groups were used: controls (C), cisplatin alone at 25 mu M (CIS), cisplatin 25 mu M plus carvedilol 50 mu M (CV + CIS), and carvedilol alone 50 mu M (CV). Cell viability, apoptosis, caspase-9, and caspase-3 were determined. Data demonstrated that carvedilol effectively increased cell viability and minimized caspase activation and apoptosis in HK-2 cells, indicating this may be a promising drug to reduce nephrotoxicity induced by cisplatin.
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Peanut samples were irradiated (0.0, 5.2, 7.2 or 10.0 kGy), stored for a year (room temperature) and examined every three months. Mycotoxic fungi (MF) were detected in non-irradiated blanched peanuts. A dose of 5.2 kGy was found suitable to prevent MF growth in blanched samples. No MF was detected in in-shell peanuts, with or without irradiation. The colors of the control in-shell and blanched samples were, respectively, 44.72 and 60.21 (L *); 25.20 and 20.38 (Chroma); 53.05 and 86.46 (degrees Hue). The water activities (Aw) were 0.673 and 0.425. The corresponding fatty acids were 13.33% and 12.14% (C16:0), 44.94% and 44.92% (C18:1,omega 9) and 37.10% and 37.63% (C18: 2,omega 6). The total phenolics (TP) were 4.62 and 2.52 mg GAE/g, with antioxidant activities (AA) of 16.97 and 10.36 mu mol TEAC/g. Storage time negatively correlated with Aw (in-shell peanuts) or L *, linoleic acid, TP and AA (in-shell and blanched peanuts) but positively correlated with Aw (blanched peanuts), and with oleic acid (in-shell and blanched peanuts). Irradiation positively correlated with antioxidant activity (blanched peanuts). No correlation was found between irradiation and AA (in-shell samples) or fatty acids and TP (in-shell and blanched peanuts). Irradiation protected against MF and retained both the polyunsaturated fatty acids and polyphenols in the samples.
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Photoprotection of the agarophyte red alga Gracilaria tenuistipitata against ultraviolet radiation (UVR) was investigated in algae submitted for 1 week to photosynthetically active radiation (PAR, 260 mu mol photons m(-2) s(-1)) or PAR + UVR (UV-A, 8.13 W m(-2) and UV-B, 0.42 W m(-2)) under different nitrogen concentrations: 0, 0.1, and 0.5 mM of NO3-. Photosynthetic pigments decreased during the time of the experiment mainly under low nitrogen supply and UVR. Incubation under high nitrogen supply (0.5 mM) sustained the photosynthetic levels over time. In contrast, mycosporine-like amino acids (MAAs) increased up to eightfold in the presence of UVR and 0.5 mM NO3-. Under PAR + UVR, maximal quantum yield was positively correlated to MAA abundance, whereas under PAR no correlation was found. The photosynthetic yield of algae cultivated during seven days under PAR + UVR was less affected by a 30-min exposure of high UVR (16 W m(-2)) and fully recovered after transferring to low PAR irradiances, whereas algae kept under PAR were more affected by UV exposure and no full recovery was observed. Growth rates decreased after three days in the presence of UVR and under low nitrate supply. However, these rates were similar when compared with treatments of PAR and PAR + UVR after seven days, with the exception of samples in 0 mM NO3-, indicating that the acclimation after one week's exposure is related to nitrate supply. In conclusion, the lowest negative effect of UVR on photosynthesis and growth rate in high N-supply-grown algae could be explained by the stimulation of photoprotection mechanisms, such as accumulation of MAAs. Photostimulation of MAA accumulation by UVR under high N supply was observed in G. tenuistipitata even after 20 years in culture without the induction of this photomorphogenic light signal.
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An electronic and vibrational spectroscopic analysis of p-coumaric acid (HCou) and its deprotonated species was performed by UV-vis and Raman, respectively, and the results were supported by density functional theory (OFT) calculations. Electronic UV-vis spectral data of HCou solutions show that the deprotonation of the carboxyl group (Cou(-)) leads to a blue shift of the lowest energy electronic transition in comparison to the neutral species, whereas the subsequent deprotonation of the phenolic moiety (Cou(2-)) carries out to a more delocalized chromophore. The DFT geometric parameters calculations suggest that the variation in the electronic delocalization for the three organic species is due to different contribution of a quinoid structure that is significantly distorted in the case of Cou(2-). The Raman data of HCou and its sodium salts show that the main spectral features that allow to differentiate the three organic species are those involving the styrene nu(C=C)(sty) vibration at 1600cm(-1) region. Even though the Raman spectra of the sodium salts of Cou(-) and Cou(2-) anions show subtle differences, the appearing of a band at ca. 1598cm(-1) in the Na(2)Cou spectrum, assigned to a mode involving the carboxylate asymmetric stretching, nu(as)(COO), and the styrene stretching, nu(C=C)(sty), is quite characteristic, as confirmed by the theoretical Raman spectrum. Considering that p-coumaric acid is an archetypical phenolic compound with several biological activities that essentially depend upon the medium pH, Raman spectroscopy results reported in this work can provide a proper way to characterize such important phytochemical compound in different protonation states. In order to complement the characterization of the sodium salts, X-ray diffraction (XRD) and thermal analysis were performed. (C) 2011 Elsevier B.V. All rights reserved.
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Quantum chemical calculations at the B3LYP/6-31G* level of theory were employed for the structure-activity relationship and prediction of the antioxidant activity of edaravone and structurally related derivatives using energy (E), ionization potential (IP), bond dissociation energy (BDE), and stabilization energies(Delta E-iso). Spin density calculations were also performed for the proposed antioxidant activity mechanism. The electron abstraction is related to electron-donating groups (EDG) at position 3, decreasing the IP when compared to substitution at position 4. The hydrogen abstraction is related to electron-withdrawing groups (EDG) at position 4, decreasing the BDECH when compared to other substitutions, resulting in a better antioxidant activity. The unpaired electron formed by the hydrogen abstraction from the C-H group of the pyrazole ring is localized at 2, 4, and 6 positions. The highest scavenging activity prediction is related to the lowest contribution at the carbon atom. The likely mechanism is related to hydrogen transfer. It was found that antioxidant activity depends on the presence of EDG at the C-2 and C-4 positions and there is a correlation between IP and BDE. Our results identified three different classes of new derivatives more potent than edaravone.
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The antioxidant activity of flavonoids may involve their ability to complex body iron in non-redox-active forms. In this study, it was found that the catechol flavonoids rutin and quercetin are able to suppress redox-active labile plasma iron (LPI) in both buffered solution and in iron-overloaded sera. Both flavonoids are effective in loading the metal into the iron-transport protein transferrin. Iron derivatives of quercetin and rutin are able to permeate cell membranes, however, only free quercetin is able to gain access to the cytosol and decrease intracellular labile iron pools. These results suggest that the antioxidant activity of quercetin may be dependent on its ability to shuttle labile iron from cell compartments followed by its transfer to transferrin. (C) 2011 Elsevier Inc. All rights reserved.