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Important Antioxidant (important + antioxidant)
Selected AbstractsGender differences in glutathione metabolism in Alzheimer's diseaseJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2005Honglei Liu Abstract The mechanism underlying Alzheimer's disease (AD), an age-related neurodegenerative disease, is still an area of significant controversy. Oxidative damage of macromolecules has been suggested to play an important role in the development of AD; however, the underlying mechanism is still unclear. In this study, we showed that the concentration of glutathione (GSH), the most abundant intracellular free thiol and an important antioxidant, was decreased in red blood cells from male AD patients compared with age- and gender-matched controls. However, there was no difference in blood GSH concentration between the female patients and female controls. The decrease in GSH content in red blood cells from male AD patients was associated with reduced activities of glutamate cysteine ligase and glutathione synthase, the two enzymes involved in de novo GSH synthesis, with no change in the amount of oxidized glutathione or the activity of glutathione reductase, suggesting that a decreased de novo GSH synthetic capacity is responsible for the decline in GSH content in AD. These results showed for the first time that GSH metabolism was regulated differently in male and female AD patients. © 2005 Wiley-Liss, Inc. [source] Hepatoprotective and antioxidant effects of Alnus japonica extracts on acetaminophen-induced hepatotoxicity in ratsPHYTOTHERAPY RESEARCH, Issue 12 2004Sang Tae Kim Abstract The stem bark of the Betulaceae plant Alnus japonica, which is indigenous to Korea, has been used as a popular folk medicine for hepatitis and cancer. In this study, the antioxidant activity of the crude extract and the hepatoprotective activities on acetaminophen (AAP)-induced toxicity in the rat liver were evaluated. We investigated the effect of the methanol (AJM) and solvent fracton of the stem bark of Alnus japonica (AJ) on AAP-induced hepatotoxicity in rats. In rat hepatocyte culture, pretreatment with AJM (50, 100, 150 and 200 µg[sol ]ml) significantly decreased the cytotoxicity of AAP in a dose-dependent manner. The pretreated with EtOAc and BuOH fraction led to an increase in free radical scavenging activity and a decrease in inhibition of lipid peroxidation, both superoxide dismutase and catalase prevent the hepatotoxicity by AAP in the treatment of A. japonica fraction. We conclude that AJ is an important antioxidant in AAP-induced live hepatotoxicity and that extract of AJM plays a hepatoprotective effects in the against AAP-induced cytotoxicity in cultured rat hepatocytes in vitro. Pending more evaluation for safety and efficacy, AJ can potentially be used in mitigating AAP-induced hepatotoxicity. Copyright © 2004 John Wiley & Sons, Ltd. [source] Determination of uric acid concentrations in human tear fluid, aqueous humour and serumACTA OPHTHALMOLOGICA, Issue 2 2009Jutta Horwath-Winter Abstract. Purpose:, The aim of this investigation was to assess and compare levels of uric acid in human tear fluid, aqueous humour and serum in cataract patients in order to obtain information about uric acid-dependent antioxidative status. Methods:, Reflex tear fluid, aqueous humour and serum were obtained from 103 cataract patients (52 women, 51 men). Uric acid was determined by a reversed phase chromatographic method with electrochemical detection. The Randox test was used to measure the contribution of uric acid to the total antioxidative status (TAS) of these body fluids. Results:, Mean concentrations of uric acid were 20 ± 8 ,g/ml in tear fluid, 18 ± 6 ,g/ml in aqueous humour and 58 ± 15 ,g/ml in serum. Significantly less uric acid was found in tear fluid (p < 0.01) and aqueous humour (p < 0.01) in female cataract patients compared with male cataract patients. There was a significant positive correlation between uric acid content in tear fluid, aqueous humour and serum, respectively (p < 0.01). The contribution of uric acid to TAS (Randox test) amounted to 38% in tear fluid, 10% in aqueous humour and 37% in serum. Conclusions:, Uric acid was found in comparable amounts in tear fluid and aqueous humour, but these were two- to threefold lower than in serum. Female cataract patients had lower uric acid values in tear fluid and aqueous humour compared with male cataract patients. Uric acid is an important antioxidant, as proven by its contribution to TAS as determined by the Randox test. The precise role of uric acid in the antioxidative reactions in tear fluid and aqueous humour is still under debate. [source] Egg carotenoids in passerine birds introduced to New Zealand: relations to ecological factors, integument coloration and phylogenyFUNCTIONAL ECOLOGY, Issue 4 2005P. CASSEY Summary 1Carotenoids are a diverse group of organic compounds that function as important antioxidants and immunostimulants and are of particular importance to developing embryos and young birds. In addition, they constitute the majority of yellow to red hues in the integumentary pigments of birds. 2We investigated the maternally derived carotenoid concentrations and balances in the yolks of eight European passerine species successfully introduced and abundant in New Zealand. Specifically, we addressed whether variation in maternally derived yolk carotenoids were related to phylogeny, integument coloration, native vs introduced distribution, breeding habitat and laying sequence. 3Across species, the concentration and balance of carotenoids deposited in yolks varied significantly. Egg carotenoid concentration was positively associated with the occurrence of male carotenoid pigmented body regions. Carotenoid concentrations differed between agricultural habitat types within New Zealand but not between samples from New Zealand and Europe. Controlling for the differences among species, and among clutches within species, increased egg carotenoid concentrations were significantly associated with decreasing fresh egg mass and eggs laid earlier in the laying sequence. 4We conclude that variability in the concentration and balance of carotenoids deposited in the egg yolk imply different relative roles for ecological and phylogenetic factors that warrant further investigation, both within and across species. [source] | |||||||||||||