|
| ||
|
|
||
Absorbance Capacity (absorbance + capacity)
Kinds of Absorbance Capacity Selected AbstractsAntioxidant capacity of human milk and its association with vitamins A and E and fatty acid compositionACTA PAEDIATRICA, Issue 11 2009A Tijerina-Sáenz Abstract Aim:, The antioxidant capacity of human milk reflects the presence and activity of multiple components, which prevent oxidative rancidity. The aim of this study was to use the Oxygen Radical Absorbance Capacity assay to assess human milk antioxidant capacity and find correlations with milk components. Methods:, Milk samples collected from 60 breastfeeding women at 1 month postpartum were assayed for antioxidant capacity, vitamins E and A, and fatty acids. Potential statistical relationships of concentrations of vitamins A and E and polyunsaturated fatty acids on the antioxidant capacity of human milk were determined. Results:, Human milk antioxidant capacity was positively attributed to ,-tocopherol concentration (, < 0.05). The vitamin A concentration did not significantly contribute to milk antioxidant capacity, but was correlated to milk ,-tocopherol concentration (r = 0.587; , < 0.001). There was no evidence of an inverse relationship between polyunsaturated fatty acids concentration and the antioxidant capacity value of milk. Conclusion:, This study shows that ,-tocopherol is an important contributor to the oxidative stability of human milk. Moreover, there was no evidence obtained to show that women who have high levels of milk polyunsaturated fatty acids are predisposed to lower milk antioxidant capacity. [source] Effect of raisin consumption on oxidative stress and inflammation in obesityDIABETES OBESITY & METABOLISM, Issue 11 2008J. W. Rankin Aim:, Oxidative stress can initiate increased inflammation that elevates risk for cardiovascular disease. The objective of this study was to determine the effects of daily consumption of raisins on markers of oxidative stress, inflammation and endothelial activation in response to an acute high-fat meal in overweight individuals. Methods:, Seventeen overweight men and women consumed 90 g raisins or isocaloric placebo (264 kcal/day) for 14 days in a randomized, crossover design while following a low-flavonoid diet. The oxidative [urinary 8-iso-prostaglandin-F2, (8-epi PGF2,) and serum oxygen radical absorbance capacity (ORAC)], inflammatory (serum C-reactive protein and interleukin-6), endothelial (serum soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1, sVCAM-1) and metabolic [free fatty acids (FFAs), triacylglycerol, glucose and insulin] response to four high-fat (53%) meals was tested pre- and postintervention. Results:, Urinary 8-epi PGF2, decreased (,22%) and fasting ORAC increased (+3%) after both interventions combined. Fasting protein-free ORAC was modestly (+3.5%) higher during the raisin than the placebo intervention. Neither the meals nor the raisins consistently induced fasted markers of inflammation or endothelial dysfunction. Gender influenced postprandial metabolic responses in that males responded with higher serum FFAs, sVCAM-1 and glucose compared with females. Conclusions:, Serum antioxidant capacity was modestly increased by daily raisin consumption, but this did not alter fasted or postprandial inflammatory response in these relatively healthy but overweight individuals. Providing all food in regular pattern reduced measures of oxidative stress. [source] Increased myocardial matrix metalloproteinases in hypoxic newborn pigs during resuscitation: effects of oxygen and carbon dioxideEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 7 2004W. B. Borke Abstract Background, Perinatal asphyxia is associated with cardiac dysfunction, and it is important to prevent further tissue injury during resuscitation. There is increasing evidence that myocardial matrix metalloproteinases (MMPs) are involved in myocardial hypoxaemia,reoxygenation injury. Objective, To assess MMPs and antioxidant capacity in newborn pigs after global ischaemia and subsequent resuscitation with ambient air or 100% O2 at different PaCO2 -levels. Methods, Newborn pigs (12,36 h of age) were resuscitated for 30 min by ventilation with 21% or 100% O2 at different PaCO2 levels after a hypoxic insult, and thereafter observed for 150 min. In myocardial tissue extracts, MMPs were analyzed by gelatin zymography and broad matrix-degrading capacity (total MMP). Total endogenous antioxidant capacity in myocardial tissue extracts was measured by the oxygen radical absorbance capacity (ORAC) assay. Results, Matrix metalloproteinase-2 more than doubled from baseline values (P < 0·001), and was higher in piglets resuscitated with 100% O2 than with ambient air (P = 0·012). The ORAC value was considerably decreased (P < 0·001). In piglets with elevated PaCO2, total MMP-activity in the right ventricle was more increased than in the left ventricle (P = 0·008). In the left ventricle, total MMPactivity was higher in the piglets with low PaCO2 than in the piglets with elevated PaCO2 (P = 0·013). Conclusion, In hypoxaemia-reoxygenation injury the MMP-2 level was highly increased and was most elevated in the piglets resuscitated with 100% O2. Antioxidant capacity was considerably decreased. Assessed by total MMP-activity, elevated PaCO2 during resuscitation might protect the left ventricle, and probably increase right ventricle injury of the myocardium. [source] N -acetylcysteine inhibits chromium hypersensitivity in coadjuvant chromium-sensitized albino guinea pigs by suppressing the effects of reactive oxygen speciesEXPERIMENTAL DERMATOLOGY, Issue 8 2010Bour-Jr Wang Please cite this paper as: N -acetylcysteine inhibits chromium hypersensitivity in coadjuvant chromium-sensitized albino guinea pigs by suppressing the effects of reactive oxygen species. Experimental Dermatology 2010; 19: e191,e200. Abstract Background:, Chromium hypersensitivity is an important issue in occupational skin disease. When hexavalent chromium enters the cell, it can be reduced to trivalent chromium, resulting in the formation of reactive oxygen species (ROS). ROS are considered to play an important role in the progression of allergic contact dermatitis. N -acetylcysteine (NAC) could increase glutathione levels in the skin and act as an antioxidant. Aims:, We attempted to demonstrate that NAC could inhibit chromium hypersensitivity in a coadjuvant chromium-sensitized albino guinea pig model by counteracting the formation of ROS. Methods:, We utilized a coadjuvant chromium-sensitized albino guinea pig model to evaluate both the severity of the skin reaction by intradermal and epicutaneous elicitation tests and the sensitization rate of chromium hypersensitivity in NAC-treated and NAC-untreated albino guinea pigs (GP). Furthermore, three ROS parameters, including H2O2, malondialdehyde (MDA) levels in the skin and the oxygen radical absorbance capacity (ORAC) in plasma, were analyzed in NAC-treated and NAC-untreated coadjuvant chromium-sensitized albino GP. Results:, The severity of the skin reaction in the intradermal and epicutaneous elicitation test significantly diminished when the albino GP were treated with a dose of 1200 mg/kg/day of NAC. This dose also significantly decreased the sensitization rate of chromium hypersensitivity. In addition, treatment with 1200 mg/kg/day of NAC significantly reduced the H2O2 and MDA levels in the skin and significantly increased the ORAC in the plasma of albino GP. Therefore, NAC could be a potential chemopreventative agent to prevent the progression of chromium hypersensitivity. [source] Effect of Heat Treatment on Antioxidant Capacity and Flavor Volatiles of MeadJOURNAL OF FOOD SCIENCE, Issue 2 2005Carol L. Wintersteen ABSTRACT: The objective of this study was to evaluate the effects of heat processing on the antioxidant capacity of mead (honey wine). Soy and buckwheat honey musts were subjected to 2 heat treatments and fermented into wine. Total phenolic concentration was determined. High-performance liquid chromatography (HPLC) phenolic profiling was performed on the methanol fraction of Amberlite extraction. Antioxidant capacity was evaluated using the oxygen radical absorbance capacity (ORAC) assay. Changes in volatile components were evaluated by headspace-solid phase microextraction/gas chromatography-mass spectrometry (H-SPME/GC-MS). ORAC values of experimental meads (3.62 mMTrolox equivalent) were comparable to those of commercial white wine (3.66 mMTrolox equivalent). No significant difference in antioxidant capacity due to heat treatment or honey type was observed. There was no difference in total phenolics between heat treatments in buckwheat mead; however, soy mead made from high-heated must had significantly greater phenolic concentration than the gently heated mead (,= 0.05). Linear regression analysis indicated a strong positive correlation between total phenolic concentration and antioxidant capacity by ORAC (r= 0.9077; P < 0.0001). HPLC analysis of phenolic profiles in the methanol fractions of Amberlite extraction of the meads indicated significantly higher levels of certain phenolics as a result of the high-heat process in buckwheat mead, but not in soy mead. Differences in volatile components that potentially impact flavor were noted between high and low heat treatments. Results of this study suggest dramatic heat treatments that are often avoided because their flavor impact in mead production have the potential to alter the antioxidant capacity of mead by changing phenolic profiles. [source] Antioxidant Status and Biomarkers of Oxidative Stress in Dogs with LymphomaJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2009J.L. Winter Background: Oxidative stress might play a role in carcinogenesis, as well as impacting morbidity and mortality of veterinary cancer patients. The purpose of this study was to evaluate antioxidant concentrations and biomarkers of oxidative stress in dogs with newly diagnosed lymphoma before treatment and once in remission, with comparison with healthy controls. Hypothesis: Dogs with lymphoma have increased oxidant and reduced antioxidant concentrations compared with healthy controls, and that these abnormalities normalize once remission is achieved. Animals: Seventeen dogs with lymphoma and 10 healthy controls. Methods: Prospective, observational study. Measures of oxidative stress [malondialdehyde and total isoprostanes (isoP)] and antioxidants [,-tocopherol, ,-tocopherol, oxygen radical absorbance capacity (ORAC), and glutathione peroxidase (GSHPx)] were assessed in dogs with newly diagnosed lymphoma before treatment compared with healthy control dogs. The same parameters were measured in the dogs with lymphoma on week 7 of the chemotherapy protocol when all dogs were in remission. Results: At baseline, dogs with lymphoma had significantly lower ,-tocopherol (P <.001) and ,-tocopherol (P= .003) but higher GSHPx (P= .05), ORAC (P= .001), and isoP (P < .001) compared with healthy controls. In the dogs with lymphoma, ,-tocopherol concentrations were higher (P= .005) and ascorbic acid were lower (P= .04) after treatment. Conclusions and Clinical Importance: Results suggest that dogs with lymphoma have alterations in oxidant and antioxidant concentrations and that the status of some of these biomarkers normalize after remission. Further studies are warranted to determine whether antioxidant interventions to correct these are beneficial in the treatment of canine lymphoma. [source] Induction of cell apoptosis in 3T3-L1 pre-adipocytes by flavonoids is associated with their antioxidant activityMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 11 2006Chin-Lin Hsu Abstract Obesity is biologically characterized at the cellular level by an increase in the number and size of adipocytes differentiated from fibroblastic pre-adipocytes in adipose tissue. In this study, we focused on the relationship between the influence of flavonoids on cell population growth and their antioxidant activity. The results showed that the inhibition of flavonoids (naringenin, rutin, hesperidin, resveratrol, naringin and quercetin) on 3T3-L1 pre-adipocytes was 28.3, 8.1, 11.1, 33.2, 5.6 and 71.5%, respectively. In oxygen radical absorbance capacity (ORAC) assay, quercetin had the highest ORACROO value among the six flavonoids tested. Apoptosis assays showed that quercetin increased apoptotic cells in time- and dose-dependent manner. Treatment of cells with quercetin decreased the mitochondrial membrane potential in the courses of time and dose. The cell apoptosis/necrosis assay showed that quercetin increased the number of apoptotic cells, but not necrotic cells. Quercetin treatment of cells caused a significant time- and dose-dependent increase in the caspase-3 activity. Western analysis indicated that treatment of quercetin markedly down-regulated PARP and Bcl-2 proteins, and activated caspase-3, Bax, and Bak proteins. These results indicate that quercetin efficiently inhibits cell population growth and induction of apoptosis in 3T3-L1 pre-adipocytes. [source] Antioxidant availability of turmeric in relation to its medicinal and culinary usesPHYTOTHERAPY RESEARCH, Issue 10 2004Jai C. Tilak Abstract Turmeric (Curcuma longa) has been used in Indian cooking, and in herbal remedies. Its possible mechanism of action was examined in terms of antioxidant availability during actual cooking conditions and in therapeutic applications using standardized extracts. The assays involve different levels of antioxidant action such as oxygen radical absorbance capacity (ORAC), radical scavenging abilities using 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2,-azobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP) and protection of membranes examined by inhibition of lipid peroxidation besides the content of phenols and total ,avonoids. The aqueous and ethanol extracts of two major preparations of turmeric, corresponding to its use in cooking and medicine, showed signi,cant antioxidant abilities. In conclusion, the studies reveal that the ability of turmeric to scavenge radicals, reduce iron complex and inhibit peroxidation may explain the possible mechanisms by which turmeric exhibits its bene,cial effects in relation to its use in cooking and medicine. Copyright © 2004 John Wiley & Sons, Ltd. [source] Antioxidant and antigenotoxic activities of Angelica keiskei, Oenanthe javanica and Brassica oleracea in the Salmonella mutagenicity assay and in HCT116 human colon cancer cellsBIOFACTORS, Issue 4 2006Daejoong Kwon Abstract Epidemiological studies indicate that consumption of green-yellow vegetables rich in chlorophyll, vitamin C, vitamin E, and carotenoids reduce the risk of cancer. We sought to examine the antigenotoxic and antioxidant properties of chlorophyll-rich methanol extracts of Angelica keiskei, Oenanthe javanica, and Brassica oleracea (kale). In the Salmonella mutagenicity assay, A. keiskei caused dose-dependent inhibition against three heterocyclic amine mutagens in the presence of S9, O. javanica was antimutagenic only at the highest concentration in the assay (2 mg/plate), and B. oleracea showed no consistent inhibitory activity at non-toxic levels. None of the extracts were effective against three direct-acting mutagens in the absence of S9. Extracts of A. keiskei and, to a lesser extent O. javanica, inhibited two of the major enzymes that play a role in the metabolic activation of heterocyclic amines, based on ethoxyresorufin-O-deethylase and methoxyresorufin-O-demethylase assays in vitro. All three plant extracts were highly effective in assays which measured ferric reducing/antioxidant power, oxygen radical absorbance capacity, and Fe2+/H2O2 -mediated DNA nicking. Finally, using the ,comet' assay, all three plant extracts protected against H2O2 -induced genotoxic damage in human HCT116 colon cancer cells. These findings provide support for the antigenotoxic and antioxidant properties of chlorophyll-rich extracts of A. keiskei, O. javanica, and B. oleracea, through mechanisms that include inhibition of carcinogen activation and scavenging of reactive oxygen species. [source] Scavenging of reactive oxygen species by novel indolin-2-one and indoline-2-thione derivatives,BIOPOLYMERS, Issue 4 2005Hassan Y. Aboul-Enein Abstract The antioxidant behavior of a series of new synthesized substituted indoline-2-ones and indolin-2-thiones was investigated in this study using an oxygen radical absorbance capacity assay (ORAC) and 2,2,-azobis(2-amidino-propane) dihydrochloride (AAPH) as the radical generator; system generating superoxide anion radical, (18-crown-6/KO2/DMSO), and the Fenton-like reaction [Co(II) + H2O2 , Co(III) + HO, + HO,]. Measurements were done using fluorescence, chemiluminescence methods, and a deoxyribose assay based on the spectrophotometry method, respectively. The results obtained indicated that the examined indoline derivatives had effective activities as radical scavengers and may be considered as an effective source for combating oxidative damage. © 2005 Wiley Periodicals, Inc. Biopolymers 78: 171,178, 2005 [source] | ||||||||||||||||