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Glutathione Reductase Activity (glutathione + reductase_activity)
Selected AbstractsEffect of Salt Stress on the Salicylic Acid Synthesis in Young Maize (Zea mays L.) PlantsJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2009G. Szalai Abstract The effect of salt stress on salicylic acid (SA) synthesis was investigated parallel with the induction of antioxidant enzymes in young maize plants. Two-week-old maize plants grown in hydroponic solution were treated with 50 or 100 mm NaCl for 7 days. Antioxidant enzyme activities, and the SA and o -hydroxy-cinnamic acid (oHCA) levels were measured on the 3rd and 7th day of treatment and after 4 days of recovery. Ascorbate peroxidase activity increased in the leaves, but changes in guaiacol peroxidase activity only could be detected in the roots after 7 days. Glutathione reductase activity increased both in the leaves and in the roots after the 3rd day of 100 mm NaCl treatment. Free SA only increased during recovery in the leaves and roots. In the leaves of plants treated with 100 mm NaCl, a slight increase was observed in the free oHCA level, which rose dramatically after recovery, while in the roots an increase could only be seen after recovery. These results suggest that oHCA may serve not only as a precursor of SA but may also have an antioxidant role during salt stress and recovery. [source] Glutathione cycle in stable chronic obstructive pulmonary diseaseCELL BIOCHEMISTRY AND FUNCTION, Issue 6 2010Biljak, Vanja Radi Abstract Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation and oxidant/antioxidant imbalance. Glutathione is the most abundant cellular low-molecular weight thiol and the glutathione redox cycle is the fundamental component of the cellular antioxidant defence system. Concentration of total glutathione and catalytic activities of glutathione peroxidase and glutathione reductase were determined in peripheral blood of patients (n,=,109) and healthy subjects (n,=,51). Concentration of total glutathione in patients was not changed in comparison to healthy controls. However, we found statistically significant difference between patients with moderate and severe disease stages. Glutathione reductase activity was increased, while glutathione proxidase activity was decreased in the patients with COPD, when compared to healthy controls. We found no significant difference in glutathione peroxidase and glutathione reductase activities between stages. Patients who smoked had lower concentration of total glutathione compared with former smokers and never-smoking patients. Lung function parameters were inversely associated with glutathione level. Evidence is presented for differential modulation of glutathione peroxidase and glutathione reductase activities in peripheral blood of patients with stable COPD. We suppose that in addition to glutathione biosynthesis, glutathione reductase-dependent regulation of the glutathione redox state is vital for protection against oxidative stress. Copyright © 2010 John Wiley & Sons, Ltd. [source] Protective effects of quercetin on ultraviolet A light-induced oxidative stress in the blood of ratJOURNAL OF APPLIED TOXICOLOGY, Issue 5 2002Ahmet Kahraman Abstract The oxidative effects of ultraviolet A (UVA) light (320,400 nm) and the antioxidant effects of quercetin were examined in rat blood. For this purpose, rats were divided into three groups: control, ultraviolet (UV) and ultraviolet + quercetin (UV + Q). The UV and UV + Q groups were irradiated for 4 h a day with UVA light (1.25 mW cm2) during periods of 3, 6 and 9 days. Quercetin (50 mg kg,1 body wt.) was administered intraperitoneally in the UV + Q group rats before irradiation periods. Blood was taken 3, 6 and 9 days post-treatment. Plasma malondialdehyde (MDA) levels significantly increased after 9 days of daily exposure to UVA. Whole blood glutathione (GSH) levels significantly declined after 3,9 days of irradiation. Glutathione peroxidase activity on days 6 and 9 and glutathione reductase activities on days 3, 6 and 9 post-irradiation were diminished significantly. Superoxide dismutase and catalase activities decreased significantly 3,9 days post-irradiation. The administration of quercetin before the 9-day period of irradiation significantly reduced the increase in plasma MDA value. Whole blood GSH levels significantly decreased with the administration of quercetin on all days. Quercetin significantly increased antioxidant enzymes diminished by UVA irradiation. Exposure of rats to UVA light leads to oxidative stress, reflected by increased MDA and reduced antioxidant enzyme levels. The administration of quercetin appears to be a useful approach to reduce the damage produced by UVA radiation. Copyright © 2002 John Wiley & Sons, Ltd. [source] Evaluation of antioxidant activity of Ginkgo biloba phytosomes in rat brainPHYTOTHERAPY RESEARCH, Issue 11 2006Suresh R. Naik Abstract Ginkgo biloba from the traditional Chinese system of medicine has been found to possess neurocognitive enhancing effects. The mechanism of action of Ginkgo seems to be related to its antioxidant properties. In the present study, Ginkgo biloba phytosomes were administered to Wistar rats at 50 mg/kg and 100 mg/kg for 7 and 14 days. Chemical hypoxia was induced by administration of sodium nitrite (75 mg/kg) 1 h after the last administration of treatment. Thirty minutes after sodium nitrite administration, the animals were killed and the cerebral cortex, cerebellum, hippocampus and striatum were isolated and homogenized. The supernatants were used for the estimation of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. Ginkgo biloba phytosome treatment was found to increase superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities in all the brain regions compared with those treated only with sodium nitrite. The prevention of depletion of the antioxidant enzymes by sodium nitrite in the presence of Ginkgo biloba phytosomes may be correlated to its antioxidant activity. Copyright © 2006 John Wiley & Sons, Ltd. [source] Ascorbate content of wheat leaves is not determined by maximal l -galactono-1,4-lactone dehydrogenase (GalLDH) activity under drought stressPLANT CELL & ENVIRONMENT, Issue 9 2005CARLOS G. BARTOLI ABSTRACT Although ascorbic acid (AA) is a high-abundance metabolite, relatively little is known about the factors controlling its accumulation in leaves. To address this issue, we examined the role of l -galactono-1,4-lactone dehydrogenase (GalLDH), the enzyme which catalyses the last step of this pathway, in the control of AA content under optimal and stress conditions. In a range of species, no clear relationship between AA content and leaf GalLDH protein and activity was found under optimal growth conditions. To explore the effect of drought stress on GalLDH activity and protein content, wheat (Triticum aestivum L.) was selected for detailed analysis, using two cultivars that differ in their constitutive AA level. In well-watered plants, the AA content of cv Buck Chambergo (BCH) was over twice that of cv Cooperativa Maipún (CM) but dehydroascorbic acid content was similar in both cv. In agreement with this, dehydroascorbate reductase and glutathione reductase activities were higher in cv BCH than in cv CM, indicating a higher capacity for AA regeneration. Neither leaf DHA content nor activities of AA regenerating enzymes were modified by drought. Although drought caused a substantial increase in GalLDH protein and activity in the low AA cv CM, this treatment had no effect on these parameters in cv BCH. Notably, leaf AA content was unaffected by drought in either cv. These results suggest that GalLDH protein and activity cannot be used as an indicator for changes in the capacity for ascorbate biosynthesis and that AA biosynthesis is constrained by other factors under stress. This can be explained by the importance of regeneration in maintaining AA levels and possibly also by redox regulation of GalLDH. [source] Glutathione cycle in stable chronic obstructive pulmonary diseaseCELL BIOCHEMISTRY AND FUNCTION, Issue 6 2010Biljak, Vanja Radi Abstract Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation and oxidant/antioxidant imbalance. Glutathione is the most abundant cellular low-molecular weight thiol and the glutathione redox cycle is the fundamental component of the cellular antioxidant defence system. Concentration of total glutathione and catalytic activities of glutathione peroxidase and glutathione reductase were determined in peripheral blood of patients (n,=,109) and healthy subjects (n,=,51). Concentration of total glutathione in patients was not changed in comparison to healthy controls. However, we found statistically significant difference between patients with moderate and severe disease stages. Glutathione reductase activity was increased, while glutathione proxidase activity was decreased in the patients with COPD, when compared to healthy controls. We found no significant difference in glutathione peroxidase and glutathione reductase activities between stages. Patients who smoked had lower concentration of total glutathione compared with former smokers and never-smoking patients. Lung function parameters were inversely associated with glutathione level. Evidence is presented for differential modulation of glutathione peroxidase and glutathione reductase activities in peripheral blood of patients with stable COPD. We suppose that in addition to glutathione biosynthesis, glutathione reductase-dependent regulation of the glutathione redox state is vital for protection against oxidative stress. Copyright © 2010 John Wiley & Sons, Ltd. [source] Chromate tolerance caused by reduced hydroxyl radical production and decreased glutathione reductase activity in Schizosaccharomyces pombeJOURNAL OF BASIC MICROBIOLOGY, Issue 2 2003Zoltán Gazdag The stable Cr(VI)-tolerant chr1-66T mutant of Schizosaccharomyces pombe, which carries one simple gene mutation responsible for Cr(VI) tolerance, accumulated and reduced the chromate anion (CrO42,) significantly more slowly than did its parental strain 6chr+. The mutant chr1-66T proved to be sensitive to oxidative stressors such as H2O2, menadione, tert -butyl hydroperoxide and Cd2+. Both the Cr(VI) tolerance and the oxidative stress sensitivity were attributed to a decreased specific glutathione reductase activity. These effects were also enhanced with a decrease in the specific mitochondrial Mn-SOD activity. [source] Lead Induced Changes in the Growth and Antioxidant Metabolism of the Lead Accumulating and Non-accumulating Ecotypes of Sedum alfrediiJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 2 2008Dan Liu Abstract The phytotoxicity and antioxidative adaptations of lead (Pb) accumulating ecotype (AE) and non-accumulating ecotype (NAE) of Sedum alfredii Hance were investigated under different Pb treatments involving 0, 0.02 mmol/L Pb, 0.1 mmol/L Pb and 0.1 mmol/L Pb/0.1 mmol/L ethylenediaminetetraacetic acid (EDTA) for 6 days. With the increasing Pb level, the Pb concentration in the shoots of AE plants enhanced accordingly, and EDTA supply helped 51% of Pb translocation to shoots of AE compared with those treated with 0.1 mmol/L Pb alone. Moreover, the presence of EDTA alleviated Pb phytotoxicity through changes in plant biomass, root morphology and chlorophyll contents. Lead toxicity induced hydrogen peroxide (H2O2) accumulation and lipid peroxidation in both ecotypes of S. alfredii. The activities of superoxide dismutase (SOD), guaiacol peroxidase (G-POD), ascorbate peroxidase, and dehydroascorbate reductase elevated in both leaves and roots of AE as well as in leaves of NAE with the increasing Pb levels, but SOD and G-POD declined in roots of NAE. Enhancement in glutathione reductase activity was only detected in roots of NAE while a depression in catalase activity was recorded in the leaves of NAE. A significant enhancement in glutathione and ascorbic acid (AsA)levels occurred in both ecotypes exposed to Pb and Pb/EDTA treatment compared with the control, however, the differences between these two treatments were insignificant. The dehydroascorbate (DHA) contents in roots of both ecotypes were 1.41 to 11.22-fold higher than those in leaves, whereas the ratios of AsA to DHA (1.38 to 6.84) in leaves altering more to the reduced AsA form were much higher than those in roots. These results suggested that antioxidative enzymes and antioxidants play an important role in counteracting Pb stress in S. alfredii. [source] Citicoline: neuroprotective mechanisms in cerebral ischemiaJOURNAL OF NEUROCHEMISTRY, Issue 1 2002Rao Muralikrishna Adibhatla Abstract Cytidine-5,-diphosphocholine (citicoline or CDP-choline), an intermediate in the biosynthesis of phosphatidylcholine (PtdCho), has shown beneficial effects in a number of CNS injury models and pathological conditions of the brain. Citicoline improved the outcome in several phase-III clinical trials of stroke, but provided inconclusive results in recent clinical trials. The therapeutic action of citicoline is thought to be caused by stimulation of PtdCho synthesis in the injured brain, although the experimental evidence for this is limited. This review attempts to shed some light on the properties of,citicoline that are responsible for its effectiveness. Our studies in transient cerebral ischemia suggest that citicoline might enhance reconstruction (synthesis) of PtdCho and sphingomyelin, but could act by inhibiting the destructive processes (activation of phospholipases). Citicoline neuroprotection may,include: (i) preserving cardiolipin (an exclusive inner mitochondrial membrane component) and sphingomyelin; (ii),preserving the arachidonic acid content of PtdCho and phosphatidylethanolamine; (iii) partially restoring PtdCho levels; (iv) stimulating glutathione synthesis and glutathione reductase activity; (v) attenuating lipid peroxidation; and (vi),restoring Na+/K+ -ATPase activity. These observed effects,of citicoline could be explained by the attenuation of,phospholipase A2 activation. Based on these findings, a singular unifying,mechanism has been hypothesized. Citicoline also provides choline for synthesis of neurotransmitter acetylcholine, stimulation of tyrosine hydroxylase activity and dopamine release. [source] Assessment of carcinogenic potential of repeated fish fried oil in miceMOLECULAR CARCINOGENESIS, Issue 10 2006Manoj K. Pandey Abstract Our prior studies have shown that single topical treatment of repeated fish fried oil extract (RFFE), containing various polycyclic aromatic hydrocarbons (PAHs), to the dorsal epidermis of mice caused enhancement of DNA damage along with higher expression of p53 and p21WAF1 proteins and cell-cycle arrest. In the present study carcinogenic potential of repeated fish fried oil (RFFO) and RFFE was assessed. Single topical application of RFFO (100 µL/animal) and RFFE (100,500 µg/animal) to Swiss albino female mice resulted in significant induction (1.8- to 7.4-fold) of ornithine decarboxylase activity. Twice weekly topical application of methylcholanthrene (MCA) for 24 wk or single topical application of 7,12-dimethylbenzanthracene (DMBA) or RFFO or RFFE, as initiator followed by twice weekly application of 12-O-tetradecanoyl phorbol myristate acetate (TPA) as promoter for 24 wk, resulted in development of skin papillomas after 6, 7, 18, and 9 wk, respectively. The cumulative number of tumors in MCA, DMBA/TPA, RFFE (200 µg)/TPA, and RFFE (500 µg)/TPA groups were 276, 168, 34, and 58 after 24 wk while negligible or minimal initiating activity was noticed in RFFO/TPA group. No tumors were found in animals either given twice weekly topical application of RFFO or a single initiating dose of DMBA followed by twice weekly application of RFFO. Histopathology of skin of animals treated with RFFE/TPA showed marked proliferation of epidermal layers along with abnormal mitosis and multinucleated tumor appearance. Skin of animals in groups RFFO/TPA and DMBA/RFFO showed sloughing and regeneration of epidermal layers, oedema along with proliferation of fibroblasts. Histochemical localization of ,-glutamyl transpeptidase was found to be substantially higher in skin of mice treated with RFFO/TPA and RFFE/TPA. Animals treated with RFFO/TPA, DMBA/RFFO, and RFFE/TPA resulted in significant induction of cutaneous aryl hydrocarbon hydroxylase (AHH) (421,432%), ethoxyresorufin-O-deethylase (252,316%), and glutathione S-transferase (133,245%) activities. Animals treated with RFFO/TPA, DMBA/RFFO, and RFFE/TPA led to significant reduction in glutathione content (39,44%) with a concomitant increase in lipid peroxidation (254,492%). Animals treated with RFFO/TPA and RFFE/TPA led a significant decrease in catalase (43,69%) and superoxide dismutase (20,31%) activities while glutathione reductase activity was found to be diminished (23,51%) in RFFO, RFFO/TPA, DMBA/RFFO, and RFFE/TPA treated groups. These results suggest that RFFE possess skin tumor initiating activity and that it may have weak promoting activity as well, which may involve free radicals. © 2006 Wiley-Liss, Inc. [source] Hepatic Effects of Rosiglitazone in Rats with the Metabolic SyndromeBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2010Zvi Ackerman In this study, we characterized the hepatic effects of rosiglitazone in fructose-enriched diet rats. Rats were randomly divided into three groups. One group was maintained on standard rat chow diet for 6 weeks, whereas the other two groups were given fructose-enriched diet for 6 weeks. Four weeks after the initiation of fructose-enriched diet, one of the fructose-enriched diet groups was also given rosiglitazone (10 mg/kg/day) for an additional 2 weeks. Rosiglitazone administration to the fructose-enriched diet rats was associated with decreases in the following parameters: blood pressure (,17%), plasma triglycerides (,62%), hepatic total lipids (,19%), hepatic triglycerides (,61%), hepatic malondialdehyde (,88%), glutathione reductase activity (,84%). An increase in adiponectin plasma levels (+329%), hepatic phospholipids (+46%), hepatic ,-tocopherol concentrations (+24%) and hepatic paraoxonase activity (+68%) was observed. Rosiglitazone caused a decrease in hepatic macrovesicular steatosis score but no change in hepatic fibrosis. Administration of rosiglitazone, to rats with the metabolic syndrome has limited hepatic favourable effects: it improves hepatic lipid metabolism, decreases macrovesicular steatosis and improves some of the hepatic oxidative,anti-oxidative milieu but has no effect on hepatic fibrosis. [source] | |||||||||||||