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Antioxidant Concentration (antioxidant + concentration)
Selected AbstractsEffects of different dietary phytase activities on the concentration of antioxidants in the liver of growing broilersJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 4 2010F. Karadas Summary One-hundred and fifty male chickens were used to evaluate the effects of different activities (0, 250, 500, 12 500 FTU/kg) of phytase on their performance and antioxidant concentration in the liver. The chicks were housed in 30 cages and were allocated to six replicates of five dietary treatments. All diets were formulated to be adequate in energy and protein (12.90 MJ/kg metabolizable energy, 214 g/kg crude protein), however, the negative control (NC) was lower in available P compared with the positive control (PC) (2.5 vs. 4.5 g/kg diet). The other three diets were the NC supplemented with phytase at 250, 500 and 12 500 FTU/kg (NC + 250, NC + 500 and NC + 12 500 FTU respectively). The concentration of antioxidants in the liver of the birds was determined using HPLC at 21 days of age. Low P diets (NC) reduced weight gain, however, supplementation with phytase improved weight gain to the extent that it was better than the PC at the 12 500 FTU treatment (p < 0.05). Feed conversion ratio was also improved by the high level of phytase supplement more than other treatments (p < 0.05). Feed consumption was not affected either by dietary phosphorus concentration or by different phytase supplementation. The antioxidant data showed that the unsupplemented diet with low phosphorus (NC) decreased the concentration of coenzyme Q10 and retinol-linoleate in the liver compared with that of birds on the adequate phosphorus treatment (PC). Phytase supplementation, especially at the higher doses (500 and 12 500 FTU) increased the level of coenzyme Q10 to the same level as the PC treatment. In addition, the highest dose (12 500 FTU) of phytase increased retinol concentration in the liver of chickens compared with those on the NC treatment. The highest inclusion level of phytase increased the ,-tocopherol level in the liver compared with the lower levels of phytase (NC + 250 and NC + 500 FTU). [source] Study of laccase production by Pleurotus ostreatus in a 5 l bioreactor and application of the enzyme to determine the antioxidant concentration of human plasmaLETTERS IN APPLIED MICROBIOLOGY, Issue 4 2008S. Mazumder Abstract Aims:, To achieve high laccase production from Pleurotus ostreatus in a bench top bioreactor and to utilize the enzyme for determination of the total antioxidant concentration (TAC) of human plasma. Methods and Results:, Laccase production by P. ostreatus studied in a benchtop bioreactor was as high as, 874·0 U ml,1 in presence of copper sulfate. The enzyme was used to replace metmyoglobin and hydrogen peroxide for the estimation of TAC in human plasma. The trolox equivalent antioxidant concentrations determined by the laccase-based method and metmyoglobin method ranged from 1·63 ± 0·011 to 1·80 ± 0·006 mmol l,1 and from 1·41 ± 0·004 to 1·51 ± 0·008 mmol l,1 plasma, respectively. Conclusions:,Pleurotus ostreatus produced high amount of extracellular laccase in a benchtop bioreactor. The enzyme can be used to assay TAC of blood plasma without the interference encountered with the hydrogen peroxide and metmyoglobin mediated assay method. Significance and Impact of the Study:, Laccase production by P. ostreatus obtained in this study was the highest among all reported laccase producing white-rot fungi. Moreover, an accurate laccase-based assay method was developed for detection of TAC in human plasma. [source] Effects of LDL-immunoapheresis on plasma concentrations of vitamin E and carotenoids in patients with familial hypercholesterolemiaJOURNAL OF CLINICAL APHERESIS, Issue 4 2004Edmund Cauza Abstract Recently very potent extracorporeal cholesterol-lowering treatment options have become available for patients with hypercholesterolemia. LDL immunoapheresis treatment selectively removes LDL and lipoprotein(a) from the circulation. Since LDL is the major carrier of lipophilic antioxidants in plasma, the purpose of the present study was to assess the effects of a single LDL apheresis treatment on plasma concentrations of tocopherols (,- and ,-tocopherol) and carotenoids (,- and ,-carotene, zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, and retinol). Plasma antioxidant concentrations were determined by HPLC in 7 patients with familial hypercholesterolemia before and after LDL immunoapheresis treatment. Plasma concentrations of both ,- and ,-tocopherol and the different carotenoids were significantly reduced by LDL apheresis. However, when standardized for cholesterol to adjust for cholesterol removal, ,- and ,-tocopherol, retinol, and the more polar carotenoids lutein and zeaxanthin increased in response to apheresis treatment, while the more unpolar carotenoids such as ,-carotene and lycopene did not change. These data demonstrate that a single LDL immunoapheresis treatment affects tocopherols and individual carotenoids differently. This may be explained by differences in chemical structure and preferential association with different lipoproteins. These results further imply that tocopherols, lutein, zeaxanthin, and retinol, are associated in part with lipoproteins and other carriers such as retinol-binding protein that are not removed during apheresis treatment. J. Clin. Apheresis 19:174,179, 2004. © 2004 Wiley-Liss, Inc. [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] Distribution, developmental and stress responses of antioxidant metabolism in MalusPLANT CELL & ENVIRONMENT, Issue 10 2004M. W. DAVEY ABSTRACT A comprehensive study was carried out to examine the interactions between the two major hydrophilic antioxidants l -ascorbate (vitamin C, l -AA), and glutathione (, -glutamyl cysteinylglycine, GSH), and other antioxidant pools in tissues of Malus, to identify factors affecting steady-state cellular concentrations. We show that in Malus, each tissue type has a characteristic and different l -AA/GSH ratio and that in fruit, exocarp (epidermal) tissue acclimated to high light has higher l -AA levels but lower GSH levels than shaded (green) areas. Maturing seeds were characterized by the highest concentrations of GSH and a highly oxidized l -AA pool. It is demonstrated that fruit seeds are capable of l -AA biosynthesis, but that this occurs exclusively by means of the Smirnoff,Wheeler pathway. By contrast, foliar tissue was also able to synthesize l -AA using uronic acid substrates. Unlike the fruit of some other plant species however, the remaining fruit tissues are incapable of de novol -AA biosynthesis. The observed differences in the steady-state concentrations of l -AA and GSH and the capacity to withstand stress in fruit, were also independent of the rates of uptake of photosynthate or of l -AA, but were correlated with the protective effect provided by phenolic compounds in these tissues. During development and maturation, l -AA and GSH levels in apple fruit declined steadily while foliar levels remained essentially constant throughout. However there was no apparent relationship between the free sugar contents of the fruit and antioxidant concentrations. [source] | |||||||||||||