Glutathione Reductase

In Tetrahymena, glutathione is synthesized from the same precursors as it is in higher animals and is present in similar intracellular concentrations. The intracellular thiol-disulfide ratio is also identical to that of mammalian tissues, due to the activity of glutathione reductase. The intracellular GSH-level was found to be dependent on the sulfur-containing amino acids in the chemically defined medium.

A large number of micropropagated Euphorbia millii shoots from temporary immersion bioreactor showed thick broad leaves that were translucent, wrinkled and/or curled and brittle, symptoms of hyperhydricity. The environment inside bioreactor normally used in plant micropropagation is characterised by high relative humidity, poor gaseous exchange between the internal atmosphere of the bioreactor and its surrounding environment, and the accumulation of ethylene, conditions that may induce physiological disorders. A comparison of hyperhydric shoots (HS) with normal plants shows marked increase in malondialdehyde (MDA) content in HS plants. MDA, a decomposition product of polyunsaturated fatty acids hydroperoxides, has been utilized very often as a suitable biomarker for lipid peroxidation, which is an effect of oxidative damage. This hypothesis is also confirmed by the higher lipoxygenase (LOX) activity in HS plants. The potential role of antioxidant enzymes in protecting hyperhydric shoots from oxidative injury was examined by analyzing enzyme activities and isozyme profiles of hyperhydric and non-hyperhydric leaves of E. millii. Superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activity were significantly higher in hyperhydric tissue as compared to non-hyperhydric normal leaf tissue. After native polyacrylamide gel electrophoresis (PAGE) analysis, seven SOD isoenzymes were detected and the increase in SOD activity observed in hyperhydric tissue seemed to be mainly due to Mn-SOD and Cu/Zn-SOD. The activity of ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) was proportionally increased in HS tissue compared to normal leaves indicating a crucial role in eliminating toxic H 2 O 2 from plant cells. The depletion of GSH and total glutathione in spite of higher GR activities observed in HS tissue indicates that mechanism of antioxidant defense was by enhanced oxidation of GSH to GSSG by DHAR yielding ascorbate (AA). The antioxidant metabolism has been shown to be important in determining the ability of plants to survive in hyperhydric stress and the up regulation of these enzymes would help to reduce the build up of ROS.

The aim of this study was to evaluate the negative effects of the Pringle maneuver on pancreatic tissue with respect to the time of performing the maneuver. Moreover, the efficacy of octreotide therapy on pancreatic changes at the time of the Pringle maneuver was assessed. Fifty male Wistar Albino rats were randomized into 5 groups. The groups were formed as follows: Group A: sham operation, Group B: Pringle maneuver for 30 min plus octreotide (PM30-OCT), Group C: Pringle maneuver for 60 min plus octreotide (PM60-OCT) and Group D: Pringle maneuver for 30 min plus 0.9 % saline solution (PM30-SS), Pringle maneuver for 60 min plus 0.9 % saline solution (PM60-SS, Group E). Blood samples for the evaluation of both amylase and lipase levels were taken via the portal vein. Levels of glutathione, glutathione reductase, catalase, myeloperoxidase, nitric oxide, xanthine oxidase, malondialdehyde, tumour necrosis factor alpha (TNF-alpha), and interleukin-1 beta (IL-1 beta) were assessed in the ...

Based on the prodrug concept as well as the combination of two different classes of antimalarial agents, we designed and synthesized two series of ferrocenic antimalarial dual molecules consisting of a ferroquine analogue conjugated with a glutathione reductase inhibitor (or a glutathione depletor) through a cleavable amide bond in order to target two essential pathways in the malarial parasites. The results showed no enhancement of the antimalarial activity of the dual molecules but evidenced a unique mode of action of ferroquine and ferrocenyl analogues distinct of those of chloroquine and nonferrocenic 4-aminoquinoline analogues.

Spice bioactive compounds, capsaicin and curcumin, were both individually and in combination examined for antilithogenic potential during experimental induction of cholesterol gallstones in mice. Cholesterol gallstones were induced by feeding mice a high-cholesterol (0.5%) diet for 10 weeks. Groups of mice were maintained on a lithogenic diet that was supplemented with 0.015% capsaicin/0.2% curcumin/0.015% capsaicin + 0.2% curcumin. The lithogenic diet that contained capsaicin, curcumin, or their combination reduced the incidence of cholesterol gallstones by 50%, 66%, and 56%, respectively, compared with lithogenic control. This was accompanied by reduced biliary cholesterol and a marginal increase in phospholipid in these spice-fed groups. Increased cholesterol saturation index and cholesterol : phospholipid ratio in the bile caused by the lithogenic diet was countered by the dietary spice compounds. The antilithogenic influence of spice compounds was attributable to the cholesterol-lowering effect of these dietary spices in blood and liver, as well as a moderate increase in phospholipids. Decreased activities of hepatic glutathione reductase and glutathione-S-transferase caused by the lithogenic diet were countered by the combination of capsaicin and curcumin. The increased lipid peroxidation and the decreased concentration of ascorbic acid in the liver that was caused by the lithogenic diet was countered by the dietary spice compounds, individually or in combination. Thus, while the capsaicin and curcumin combination did not have an additive influence in reducing the incidence of cholesterol gallstones in mice, their combination nevertheless was more beneficial in enhancing the activity of hepatic antioxidant enzyme ─ glutathione reductase in the lithogenic situation. The antioxidant effects of dietary spice compounds are consistent with the observed reduction in cholesterol gallstones formed under lithogenic condition.

Glutathione is involved in thiol redox signaling and acts as a major redox buffer against reactive oxygen species, helping to maintain a reducing environment in vivo. Glutathione reductase (GR) catalyzes the reduction of glutathione disulfide (GSSG) into reduced glutathione (GSH). The Arabidopsis thaliana genome encodes two GRs: GR1 and GR2. Whereas the cytosolic/ peroxisomal GR1 is not crucial for plant development, we show here that the plastid-localized GR2 is essential for root growth and root apical meristem (RAM) maintenance. We identify a GR2 mutant, miao, that displays strong inhibition of root growth and severe defects in the RAM, with GR activity being reduced to ;50%. miao accumulates high levels of GSSG and exhibits increased glutathione oxidation. The exogenous application of GSH or the thiol-reducing agent DTT can rescue the root phenotype of miao, demonstrating that the RAM defects in miao are triggered by glutathione oxidation. Our in silico analysis of public microarray data shows that auxin and glutathione redox signaling generally act independently at the transcriptional level. We propose that glutathione redox status is essential for RAM maintenance through both auxin/PLETHORA (PLT)dependent and auxin/PLT-independent redox signaling pathways.

Oxidative stress is one of the major factors leading to Maneb-and Zineb-induced disorders. The aim of this in vitro study was to examine (i) the potency of Maneb and Zineb to induce changes in antioxidant enzyme activities in Chinese hamster fibroblasts V79 cells and (ii) the role of N-acetyl-L-cysteine (NAC) in the preventing their action. Maneb increased mitochondrial superoxide dismutase (SOD2) activity but failed to affect the activity of cytoplasmic superoxide dismutase (SOD1), whereas Zineb did not change the activity of any of superoxide dismutases. The activity of catalase (CAT) was reduced only by Zineb. The activity of both glutathione peroxidases (non-Se-GPx, Se-GPx) and glutathione reductase (GR) was decreased after exposure to these agents. After NAC pre-treatment Maneb increased the activity of GR, whereas the activity of non-Se-GPx was decreased as compared to that in NAC-treated cells. On the other hand, the activity of both SODs and CAT was decreased. Zineb decreased the activity of both GPxs and SOD2 with a concomitant increase in CAT activity comparing to NAC-treated cells. The results obtained thus suggest that Zineb acts by another mechanism, than Maneb does, and that one of the mechanisms of NAC protection against Maneb or Zineb-induced effects in V79 cells is its impact on enzymatic defense. Activity of GR, SOD2, and GPxs are the most affected enzymes.

Caffeic acid (CA), which is ubiquitously present in plants, is a potent phytotoxin affecting plant growth and physiology. The aim of our study was to investigate whether CA-induced inhibition of adventitious root formation (ARF) in mung bean {Vigna radiata (L.) Wilczek [Phaseolus aureus Roxb.]} involves the induction of conventional stress responses. The effect of CA (0–1000 μM) on ARF in mung bean was determined by measuring the generation of reactive oxygen species (ROS) in terms of malondialdehyde and hydrogen peroxide (H2O2) content, root oxidizability and changes in levels of antioxidant enzymes. Our results show that CA significantly enhanced MDA content, indicating severe lipid peroxidation, and increased H2O2 accumulation and root oxidizability in the lower rooted hypocotylar region (LRHR) of mung bean, thereby inducing oxidative stress and cellular damage. In response to CA, there was a significant upregulation in the activities of scavenging enzymes, such as superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, catalase and glutathione reductase, in LRHRs of mung bean. Based on these results, we conclude that CA inhibits ARF in mung bean hypocotyls by inducing ROS-generated oxidative stress and upregulating the activities of antioxidant enzymes.

Ubiquinol is a powerful antioxidant, which is oxidized in action and needs to be replaced or regenerated to be capable of a sustained effort. This article summarises current knowledge of extramitochondrial reduction of ubiquinone by three flavoenzymes, i.e. lipoamide dehydrogenase, glutathione reductase and thioredoxin reductase, belonging to the same pyridine nucleotide-disulfide oxidoreductase family. These three enzymes are the most efficient extramitochondrial ubiquinone reductases so far described. The reduction of ubiquinone by lipoamide dehydrogenase and glutathione reductase is potently stimulated by zinc and the highest rate of reduction is achieved at acidic pH and the rates are equal with either NADPH or NADH as co-factors. The most efficient ubiquinone reductases are mammalian cytosolic thioredoxin reductases, which are selenoenzymes with a number of biological functions. Reduction of ubiquinone by thioredoxin reductase is in contrast to the other two enzymes investigated, inhibited by zinc and shows a sharp physiological pH optimum at pH 7.5. Furthermore, the reaction is selenium dependent as revealed from experiments using truncated and mutant forms of the enzyme and also in a cellular context by selenium treatment of transfected thioredoxin reductase overexpressing stable cell lines. The reduction of ubiquinone by the three enzymes offers a multifunctional system for extramitochondrial regeneration of an important antioxidant.

Two experiments were conducted to evaluate the response of sows to high levels of dietary riboflavin. Responses evaluated were erythrocyte glutathione reductase activity coefficient (EGRAC, a biochemical indicator of riboflavin status) and reproductive performance. In Exp. 1, eight sows were fed diets either slightly deficient or superadequate in riboflavin throughout a reproductive cycle, beginning in midgestation. The EGRAC values confirmed the slight deficiency (P < .01) but did not clearly show a time when the sow is most likely to be deficient in riboflavin. In Exp. 2, 118 sows at two farms were fed diets providing 10 (control, 1.4 times the NRC [1988] requirement estimate), 60, 110, or 160 mg of riboflavin/d for 21 d beginning at breeding, and the control level through the remainder of the reproductive cycle. The percentage of sows farrowing tended to be lower (P < .10) for the control sows than for sows fed the other treatments (66.7, 85.7, 93.3, and 86.7% for 10, 60, 1...

The effect of arbuscular mycorrhizal (AM) fungi inoculation on pepper (Capsicum annuum L. cv. Zhongjiao 105) plant growth and on some physiological parameters in response to increasing soil Cu concentrations was studied. Treatments consisted of inoculation or not with Glomus mosseae and the addition of Cu to soil at the concentrations of 0 (control), 2 (low), 4 (medium), and 8 (high) mM CuSO 4. AM fungal inoculation decreased Cu concentrations in plant organs and promoted biomass yields as well as the contents of chlorophyll, soluble sugar, total protein, and the concentrations of P, K, Ca, and Mg. Plants grown in high Cu concentration exhibited a Cu-induced proline accumulation and also an increase in total free amino acid contents; however, both were lower in mycorrhizal pepper. Cu-induced oxidative stress by increasing lipid peroxidation rates and the activity of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase, and AM symbiosis enhanced these antioxidant enzyme activities and decreased oxidative damage to lipids. In conclusion G. mosseae was able to maintain an efficient symbiosis with pepper plants in contaminated Cu soils, improving plant growth under these conditions, which is likely to be due to reduced Cu accumulation in plant tissues, reduced oxidative stress and damage to lipids, or enhanced antioxidant capacity.

This study used rainbow trout (Oncorhynchus mykiss) to investigate the biological e4ects of long-term exposure to a total chlorine-free (TCF) pulp mill e8uent. Fish tanks were set up on the premises of the pulp mill, and fresh e8uent water was led through a pipe directly from the pulp mill to the tanks. The 5sh were exposed to e8uent for up to 50 days and kept for up to 70 days afterward to study the recovery process. Two independent experiments were carried out. Ethoxyresoru5n-O-deethylase (EROD), glutathione-S-transferase (GST), and glutathione reductase (GR) activity were elevated in 5sh exposed to a 2% concentration of pulp mill e8uent, as were levels of DNA adducts. These e4ects could be detected during exposure and also after a period of recovery. The results demonstrate that the pulp mill e8uent contains substances that a4ect the detoxi5cation process and also have genotoxic potential. The continued occurrence of e4ects after a 70-day recovery period was demonstrated in both experiments, and may indicate that the e8uent contained compounds with persistent properties The content of free and conjugated resin acids in the bile of the 5sh was found to be a useful indicator of exposure to pulp mill e8uent. 2002 Elsevier Science (USA) 238 0147-6513/02 $35.00 2002 Elsevier Science (USA) All rights reserved.

The purpose of this study was to evaluate behavioral responses and biochemical changes induced by the extensively used pesticide cypermethrin (CYP) in liver, gills, brain and muscle tissues of mahseer (Tor putitora) fry. Behavioral changes in fish after exposure to an acute concentration of CYP involved jumping, abrupt swimming, loss of balance and equilibrium, increased surface activity and air gulping. These changes were more prominent with the passage of time. After a longer period of exposure, the fish became sluggish and before dying occasionally became motionless and sometimes showed a vertical position. Internal hemorrhage was also obvious. CYP exposure resulted in a significant decrease in total protein content in different tissues while antioxidant enzymes, catalase (CAT), peroxidase (POD) and glutathione reductase (GR) showed a time-dependent increasing trend in their activities in liver, brain, gills and muscle tissues. Similarly, lipid peroxidation (LPO) level also incre...

We present two different methods for determining levels of glutathione in complex biological samples and plasma. The DTNB/GR enzyme recycling method is sensitive and requires no specialized equipment. The HPLC method is particularly useful for situations in which sample amounts are limited. Detailed instructions for performing each method as well as the advantages and disadvantages of each are discussed in this chapter.

Sulforaphane [1-isothiocyanate-(4R)-(methylsulfinyl)butane] is a natural dietary isothiocyanate produced by the enzymatic action of the myrosinase on glucopharanin, a 4-methylsulfinylbutyl glucosinolate contained in cruciferous vegetables of the genus Brassica such as broccoli, brussel sprouts, and cabbage. Studies on this compound is increasing because its anticarcinogenic and cytoprotective properties in several in vivo experimental paradigms associated with oxidative stress such as focal cerebral ischemia, brain inflammation, intracerebral hemorrhage, ischemia and reperfusion induced acute renal failure, cisplatin induced-nephrotoxicity, streptozotocin-induced diabetes, carbon tetrachloride-induced hepatotoxicity and cardiac ischemia and reperfusion. This protective effect also has been observed in in vitro studies in different cell lines such as human neuroblastoma SH-SY5Y, renal epithelial proximal tubule LLC-PK1 cells and aortic smooth muscle A10 cells. Sulforaphane is considered an indirect antioxidant; this compound is able to induce many cytoprotective proteins, including antioxidant enzymes, through the Nrf2-antioxidant response element pathway. Heme oxygenase-1, NAD(P)H: quinone oxidoreductase, glutathione-S-transferase, gamma-glutamyl cysteine ligase, and glutathione reductase are among the cytoprotective proteins induced by sulforaphane. In conclusion, sulforaphane is a promising antioxidant agent that is effective to attenuate oxidative stress and tissue/cell damage in different in vivo and in vitro experimental paradigms.

Alterations of antioxidant enzyme activities have been described in a number of psychiatric disorders including major depression. Subsequently, the present study examined the effects of different types of antidepressants (desipramine, imipramine, maprotiline and mirtazapine) in different concentrations (10 − 5 , 10 − 6 and 10 − 7 M) on the mRNA levels of various enzymes of the antioxidant system, including both intracellular superoxide dismutase isoforms, glutathione peroxidase and catalase as well as several enzymes of the glutathione metabolism in monocytic U-937 cells after short-and long-term treatment (2.5 and 24 h) via RT-PCR. Results indicated mainly short-term decreases in the mRNA levels of antioxidant enzymes after treatment with these substances in all the concentrations used. In addition, after long-term treatment, significant increases in the mRNA levels were seen in the cases of Cu, Zn superoxide dismutase, γ-glutamylcysteine synthetase, glutathione-S-transferase and glutathione reductase, including the impacts of all the antidepressants used in concentrations of 10 − 6 M and 10 − 7 M. Based on the large number of significant effects of all types of antidepressants tested on various antioxidant enzymes, we suggest that antioxidant enzymes may represent important targets in the course of antidepressive treatment.

The effect of ionized air containing negatively charged ions at a concentration of 320000–350000 ions/cm3 inhaled by rats was studied. It was demonstrated that the inhalation of negative air ions for 60 min activated the secretion of goblet cells without impairing the tracheal mucosa and changing the protein profile of bronchoalveolar lavage. It was also found that the level of spontaneous production of reactive oxygen species by unfractionated blood cells increased after the action of negative air ions in both males and females. However, the intensity of their generation induced by opsonized zymosan increased only in females. Different sensitivities of the female and male blood antioxidant enzymes—superoxide dismutase and glutathione reductase—to negative air ions were observed. These results allow the effect of negative air ions on the respiratory organs and blood to be interpreted as priming and weak activation via a direct action on the mucosa of primary target respiratory organs and then on the blood.

Trypanosomes and leishmania, the causative agents of several tropical diseases, possess a unique redox metabolism which is based on trypanothione. The bis(glutathionyl)spermidine is the central thiol that delivers electrons for the synthesis of DNA precursors, the detoxification of hydroperoxides and other trypanothione-dependent pathways. Many of the reactions are mediated by tryparedoxin, a distant member of the thioredoxin protein family. Trypanothione is kept reduced by the parasite-specific flavoenzyme trypanothione reductase. Since glutathione reductases and thioredoxin reductases are missing, the reaction catalyzed by trypanothione reductase represents the only connection between the NADPH-and the thiolbased redox metabolisms. Thus, cellular thiol redox homeostasis is maintained by the biosynthesis and reduction of trypanothione. Nearly all proteins of the parasite-specific trypanothione metabolism have proved to be essential.

Cognitive deficits and psychiatric disorders are significant sequelae of traumatic brain injury (TBI). Animal models have been widely employed in TBI research, but few studies have addressed the effects of experimental TBI of different severities on emotional and cognitive parameters. In this study, mice were subjected to weight-drop TBI to induce mild, intermediate, or severe TBI. After neurological assessment, the mice recovered for 10 days, and were then subjected to a battery of behavioral tests, which included open-field, elevated plus-maze, forced swimming, tail suspension, and step-down inhibitory avoidance tests. Oxidative stressrelated parameters (nonprotein thiols [NPSH], glutathione peroxidase [GPx], glutathione reductase [GR], and thiobarbituric acid reactive species [TBARS]) were quantified in the cortex and hippocampus at 2 and 24 h and 14 days after TBI, and histopathological analysis was performed 15 days after TBI. Mice subjected to mild TBI showed increased anxiety and depressive-like behaviors, while intermediate and severe TBI induced robust memory deficits. The severe TBI group also displayed increased locomotor activity. Intermediate and severe TBI caused extensive macroscopic and microscopic brain damage, while mild TBI typically had no histological abnormalities. Moreover, a significant increase in TBARS in the ipsilateral cortex and GPx in the ipsilateral hippocampus was observed at 24 h and 14 days, respectively, following intermediate TBI. The current experimental TBI model induced emotional and cognitive changes comparable to sequelae seen in human TBI, and it might therefore represent a useful approach to the study of mechanisms of and new treatments for TBI and related disorders.

There is an increasing body of evidence to support the significant role of invertebrates in assessing impacts of environmental contaminants on marine ecosystems. Therefore, in recent years massive efforts have been directed to identify viable and ecologically relevant invertebrate toxicity testing models. Tigriopus, a harpacticoid copepod has a number of promising characteristics which make it a candidate worth consideration in such efforts. Tigriopus and other copepods are widely distributed and ecologically important organisms. Their position in marine food chains is very prominent, especially with regard to the transfer of energy. Copepods also play an important role in the transportation of aquatic pollutants across the food chains. In recent years there has been a phenomenal increase in the knowledge base of Tigriopus spp., particularly in the areas of their ecology, geophylogeny, genomics and their behavioural, biochemical and molecular responses following exposure to environmental stressors and chemicals. Sequences of a number of important marker genes have been studied in various Tigriopus spp., notably T. californicus and T. japonicus. These genes belong to normal biophysiological functions (e.g. electron transport system enzymes) as well as stress and toxic chemical exposure responses (heat shock protein 20, glutathione reductase, glutathione S-transferase). Recently, 40,740 expressed sequenced tags (ESTs) from T. japonicus, have been sequenced and of them, 5673 ESTs showed significant hits (E-value, >1.0E−05) to the red flour beetle Tribolium genome database. Metals and organic pollutants such as antifouling agents, pesticides, polycyclic aromatic hydrocarbons (PAH) and polychrlorinated biphenyls (PCB) have shown reproducible biological responses when tested in Tigriopus spp. Promising results have been obtained when Tigriopus was used for assessment of risk associated with exposure to endocrine-disrupting chemicals (EDCs). Application of environmental gene expression techniques has allowed evaluation of transcriptional changes in T. japonicus with the ultimate aim of understanding the mechanisms of action of environmental stressors. Through a better understanding of toxicological mechanisms, ecotoxicologists may use this ecologically relevant species in risk assessment studies in marine systems. The combination of uses as a whole-animal bioassay and gene expression studies indicate that Tigriopus may serve as an excellent tool to evaluate the impacts of marine pollution throughout the coastal region. The purpose of this review is to illustrate the potential of using Tigriopus to fulfill the niche as an important invertebrate marine model organism for ecotoxicology and environmental genomics. In addition, the knowledge gaps and areas for further studies have also been discussed.

Two varieties of guava viz., L-49 and Hisar Safeda differing in their shelf lives were analyzed for various components of oxidative stress and of enzymatic and non-enzymatic antioxidative system at different stages of fruit ripening. Indices of oxidative stress viz., lipoxygenase activity, malondialdehyde value and H2O2 content increased throughout during ripening in both the varieties. The extent of oxidative stress was more pronounced in Hisar Safeda (shelf life 3–4 days) than in L-49 (shelf life 7–8 days). Except for superoxide dismutase, activities of all other antioxidative enzymes viz., catalase, peroxidase, ascorbate peroxidase and glutathione reductase increased up to color turning stage and decreased thereafter. Superoxide dismutase activity, however, increased upto ripe stage followed by a decline. Contents of ascorbic acid and glutathione (total, oxidized and reduced) were found to be the maximum at turning and mature stage, respectively. It is inferred that ripening of guava fruit is accompanied by a progressive increase in oxidative/peroxidative stress which induces antioxidant system but not until later stages of ripening. Over-accumulation of ROS due to dysfunctioning of ROS scavenging system at later stages of fruit ripening appears to be responsible for loss of tissue structure as observed in ripened and over-ripened fruits.

Lack of oxygen is life threatening for most mammals. It is therefore of biomedical interest to investigate the adaptive mechanisms which enable mammalian species to tolerate extremely hypoxic conditions. The subterranean mole rat Spalax survives substantially longer periods of hypoxia than the laboratory rat. We hypothesized that genes of the antioxidant defense, detoxifying harmful reactive oxygen species generated during hypoxia and hyperoxia, are involved in Spalax underground adaptation. Using quantitative RT-PCR, we analyzed the mRNA expression levels of seven antioxidant defense genes (catalase, glutathione peroxidase 1, glutathione-S-transferase Pi1, heme oxygenase 1, superoxide dismutase 1 and 2) and a master regulator of this stress pathway, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in several tissues of two Israeli Spalax species, S. galili (2n = 52) and S. judaei (2n = 60), and rat. We also studied the differential expression of these genes after experimental hypoxia and hyperoxia as oxidative stress treatments. We found that mRNA levels and transcriptional responses are species and tissue specific. There are constitutively higher transcript levels of antioxidant genes and their transcription factor Nrf2 in Spalax tissue as compared to rat, suggesting an increased ability in the mole rat to withstand hypoxic/hyperoxic insults. In contrast to Spalax, the rat reacts to experimental oxidative stress by changes in gene regulation. In addition, Spalax Nrf2 reveals unique amino acid changes, which may be functionally important for this transcription factor and indicate positive (Darwinian) selection. Antioxidant defense genes are therefore important targets for adaptive change during evolution of hypoxia tolerance in Spalax.

Colon cancer is the third most common malignant neoplasm in the world and it remains an important cause of death, especially in western countries. The toxic environmental pollutant, 1, 2-dimethylhydrazine (DMH), is also a colon-specific carcinogen. Tannic acid (TA) is reported to be effective against various types of chemically induced toxicity and also carcinogenesis. In the present study, we evaluated the chemopreventive efficacy of TA against DMH induced colon toxicity in a rat model. Efficacy of TA against the colon toxicity was evaluated in terms of biochemical estimation of antioxidant enzyme activities, lipid peroxidation, histopathological changes and expression of early molecular markers of inflammation and tumor promotion. DMH treatment induced oxidative stress enzymes (p<0.001) and an early inflammatory and tumor promotion response in the colons of Wistar rats. TA treatment prevented deteriorative effects induced by DMH through a protective mechanism that involved redu...

Background and aim: Extra virgin olive oil has been associated with a reduced incidence of risk factors for coronary heart disease also owing to the presence of antioxidant biophenols. This study compared the protective effects of tyrosol and hydroxytyrosol, two biophenols greatly different in antioxidant power, on J774 A.1-mediated oxidation of LDL. Methods and results: Cell-mediated oxidation of LDL was evaluated by TBARS formation, and relative electrophoretic mobility increase. Redox imbalance was studied by: (i) cytofluorimetric determination of intracellular ROS and GSH, and (ii) evaluation of GSH-related enzyme activities and gene expressions by colorimetric and RT-PCR analyses, respectively. The cellular uptake of the biophenols was evaluated by HPLC. Both biophenols inhibited cell-mediated oxidation of LDL but to a different extent (100% hydroxytyrosol vs 40% tyrosol), and counteracted the impairment of antioxidant cellular defence, i.e., GSH and related enzymes. Tyrosol was effective in inhibiting about 30% of ROS production only at later time-points (12 h for superoxide, 24 h for hydrogen peroxides). Interestingly, both biophenols were effective when added to the cells for 2 h and removed before LDL treatment. This was probably related to cellebiophenol interactions: hydroxytyrosol was rapidly found inside the cells (1.12 AE 0.05 ng/mg cell protein) and disappeared * Corresponding author. Tel./fax: þ39 649902763. Nutrition, Metabolism & Cardiovascular Diseases (2007) 17, 535e545 www.elsevier.com/locate/nmcd within 18 h, while tyrosol accumulated intracellularly with time (0.68 AE 0.09 vs 1.72 AE 0.13 ng/mg cell protein at minute 5 and hour 18, respectively). Conclusions: In spite of its weak antioxidant activity, tyrosol was effective in preserving cellular antioxidant defences, probably by intracellular accumulation. These findings give further evidence in favour of olive oil consumption to counteract cardiovascular diseases. ª

The Tardigrade Resistance to Space Effects (TARSE) project, part of the mission LIFE on FOTON-M3, analyzed the effects of the space environment on desiccated and active tardigrades. Four experiments were conducted in which the eutardigrade Macrobiotus richtersi was used as a model species. Desiccated (in leaf litter or on paper) and hydrated tardigrades (fed or starved) were flown on FOTON-M3 for 12 days in September 2007, which, for the first time, allowed for a comparison of the effects of the space environment on desiccated and on active animals. In this paper, we report the experimental design of the TARSE project and data on tardigrade survival. In addition, data on survival, genomic DNA integrity, Hsp70 and Hsp90 expressions, antioxidant enzyme contents and activities, and life history traits were compared between hydrated starved tardigrades flown in space and those maintained on Earth as a control. Microgravity and radiation had no effect on survival or DNA integrity of active tardigrades. Hsp expressions between the animals in space and the control animals on Earth were similar. Spaceflight induced an increase of glutathione content and its related enzymatic activities. Catalase and superoxide dismutase decreased with spaceflight, and thiobarbituric acid reactive substances did not change. During the flight mission, tardigrades molted, and females laid eggs. Several eggs hatched, and the newborns exhibited normal morphology and behavior.

Oxidative stress is implicated in the pathogenesis of diabetic nephropathy. The attempts to identify early markers of diabetes-induced renal oxidative injury resulted in contradictory findings. We characterized early oxidative stress in renal cortex of diabetic rats, and evaluated whether it can be prevented by the potent antioxidant, DL-␣-lipoic acid. The experiments were performed on control rats and streptozotocin-diabetic rats treated with/without DL-␣-lipoic acid (100 mg/kg i.p., for 3 weeks from induction of diabetes). Malondialdehyde plus 4-hydroxyalkenal concentration was increased in diabetic rats vs. controls (p Ͻ .01) and this increase was partially prevented by DL-␣-lipoic acid. F 2 isoprostane concentrations (measured by GCMS) expressed per either mg protein or arachidonic acid content were not different in control and diabetic rats but were decreased several-fold with DL-␣-lipoic acid treatment. Both GSH and ascorbate (AA) levels were decreased and GSSG/GSH and dehydroascorbate/AA ratios increased in diabetic rats vs. controls (p Ͻ .01 for all comparisons), and these changes were completely or partially (AA) prevented by DL-␣-lipoic acid. Superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione transferase, and NADH oxidase, but not catalase, were upregulated in diabetic rats vs. controls, and these activities, except glutathione peroxidase, were decreased by DL-␣-lipoic acid. In conclusion, enhanced oxidative stress is present in rat renal cortex in early diabetes, and is prevented by DL-␣-lipoic acid.

Coal tar is a significant product generated from coal pyrolysis. Coal tar can be utilized as raw materials for various industries. It is also a type of raw material from which phenols, naphthalenes, and anthracene can be extracted. The present study was designed to investigate the possibility of coal tar creosote to induce oxidative stress and biochemical perturbations in rat liver and the role of rosemary (Rosmarinus officinalis) in ameliorating its toxic effects. Male Wister Albino rats were randomly divided into four groups of seven each, group I served as control; group II treated with rosemary (10 mL of water extract/kg BW for 21 days), group III received coal tar creosote (200 mg/4 mL olive oil/kg BW for 3 days), and group IV treated with both rosemary and coal tar creosote. The administration of coal tar creosote significantly caused elevation in lipid peroxidation (LPO) and reduction in the activities of glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST). A significant decrease in reduced glutathione (GSH) content was also observed. Liver aminotransferases aspartate transaminase (AST) and alanine transaminase (ALT)] and alkaline phosphatase (AlP) were significantly decreased while lactate dehydrogenase (LDH) was increased. Rosemary pretreatment to coal tar creosote-treated rats decreased LPO level and normalized GPx, GR, SOD, CAT, and GST activities, while GSH content was increased. Also, liver AST, ALT, AlP, and LDH were maintained near normal level due to rosemary treatment. In conclusion, rosemary has beneficial effects and could be able to antagonize coal tar creosote toxicity.

Thiols (-SH groups) are the main form of reduced sulphur in plants present as protein thiols (Cys residues) or low molecular weight thiols, the most prominent is the tripeptide glutathione (GSH). Due to the redox properties of the thiol groups these compounds play important roles in stress responses of plants, since stress is nearly always associated with an enhanced formation of reactive oxygen species (ROS). Because of its antioxidative properties, GSH is directly involved in protection of cells from ROS damage and in regeneration of oxidized substrates. GSH is kept in the active reduced state by glutathione reductase (GR). In the following chapter, responses of GSH and GR system to natural abiotic stresses (drought, low and high temperatures, high light, UV, salinity, anoxia), biotic stresses (pathogen infection), and air pollution impact are discussed. The reviewed results show that plant resistance to stress is commonly correlated with increased GSH contents and GR activities. Damage to plant tissues is often marked by a breakdown of the GSH system. Besides its role as protectant, GSH is thought to play a role in cellular signalling and stress sensing. Apart from GSH, small protein thiols (thioredoxins) are essential for the adjustment of metabolism to environmental conditions. Most recent results suggest that thioredoxins can be directly induced by ROS stress. The role of thiols in regulation of plant stress responses, e.g. by inducing defense enzymes and compounds, is discussed.

There is an increasing body of evidence to support the significant role of invertebrates in assessing impacts of environmental contaminants on marine ecosystems. Therefore, in recent years massive efforts have been directed to identify viable and ecologically relevant invertebrate toxicity testing models. Tigriopus, a harpacticoid copepod has a number of promising characteristics which make it a candidate worth consideration in such efforts. Tigriopus and other copepods are widely distributed and ecologically important organisms. Their position in marine food chains is very prominent, especially with regard to the transfer of energy. Copepods also play an important role in the transportation of aquatic pollutants across the food chains. In recent years there has been a phenomenal increase in the knowledge base of Tigriopus spp., particularly in the areas of their ecology, geophylogeny, genomics and their behavioural, biochemical and molecular responses following exposure to environmental stressors and chemicals. Sequences of a number of important marker genes have been studied in various Tigriopus spp., notably T. californicus and T. japonicus. These genes belong to normal biophysiological functions (e.g. electron transport system enzymes) as well as stress and toxic chemical exposure responses (heat shock protein 20, glutathione reductase, glutathione S-transferase). Recently, 40,740 expressed sequenced tags (ESTs) from T. japonicus, have been sequenced and of them, 5673 ESTs showed significant hits (E-value, >1.0E−05) to the red flour beetle Tribolium genome database. Metals and organic pollutants such as antifouling agents, pesticides, polycyclic aromatic hydrocarbons (PAH) and polychrlorinated biphenyls (PCB) have shown reproducible biological responses when tested in Tigriopus spp. Promising results have been obtained when Tigriopus was used for assessment of risk associated with exposure to endocrine-disrupting chemicals (EDCs). Application of environmental gene expression techniques has allowed evaluation of transcriptional changes in T. japonicus with the ultimate aim of understanding the mechanisms of action of environmental stressors. Through a better understanding of toxicological mechanisms, ecotoxicologists may use this ecologically relevant species in risk assessment studies in marine systems. The combination of uses as a whole-animal bioassay and gene expression studies indicate that Tigriopus may serve as an excellent tool to evaluate the impacts of marine pollution throughout the coastal region. The purpose of this review is to illustrate the potential of using Tigriopus to fulfill the niche as an important invertebrate marine model organism for ecotoxicology and environmental genomics. In addition, the knowledge gaps and areas for further studies have also been discussed.

Copyright © 2005 by Humana Press Inc. All rights of any nature whatsoever reserved. 0273-2289/05/125/0127/$30.00 ... *Author to whom all correspondence and reprint requests should be addressed. ... MUSTAFA ERAT,1 HÜLYA DEMiR,2 AND HALiS S¸AKiROG˘LU*,2

There is a great deal of interest in neurotrophin therapy to prevent neuronal degeneration. The present study aimed at synthesizing new functionalized indole derivatives with structures justifying neuroprotective activity using l-tryptophan (TRP)†Abbreviations: ACR, acrylamide; AD, adrenaline; b.wt., body weight; CK, creatine kinase; DA, dopamine; GPx, glutathione peroxidase, GR, glutathione reductase; GSH, glutathione content; 5-HT, serotonin; ip, intraperitoneal; LDH, lactate dehydrogenase;

Radiation hazards in outer space present an enormous challenge for the biological safety of astronauts. A deleterious effect of radiation is the production of reactive oxygen species, which result in damage to biomolecules (e.g., lipid, protein, amino acids, and DNA). Understanding free radical biology is necessary for designing an optimal nutritional countermeasure against space radiation–induced cytotoxicity. Free radicals (e.g., superoxide, nitric oxide, and hydroxyl radicals) and other reactive species (e.g., hydrogen peroxide, peroxynitrite, and hypochlorous acid) are produced in the body, primarily as a result of aerobic metabolism. Antioxidants (e.g., glutathione, arginine, citrulline, taurine, creatine, selenium, zinc, vitamin E, vitamin C, vitamin A, and tea polyphenols) and antioxidant enzymes (e.g., superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidases) exert synergistic actions in scavenging free radicals. There has been growing evidence over the past three decades showing that malnutrition (e.g., dietary deficiencies of protein, selenium, and zinc) or excess of certain nutrients (e.g., iron and vitamin C) gives rise to the oxidation of biomolecules and cell injury. A large body of the literature supports the notion that dietary antioxidants are useful radioprotectors and play an important role in preventing many human diseases (e.g., cancer, atherosclerosis, stroke, rheumatoid arthritis, neurodegeneration, and diabetes). The knowledge of enzymatic and non-enzymatic oxidative defense mechanisms will serve as a guiding principle for establishing the most effective nutrition support to ensure the biological safety of manned space missions.

The aim of this study was to investigate effect of antiemetics on G6PD and antioxidant enzymes. Antiemetics are currently being used to reduce or prevent nausea and vomiting in patients. This is the first study to show effect of antiemetics on glucose-6-phosphate dehydrogenase (G6PD) and antioxidant enzyme activities. For in vitro studies, G6PD was purified from human erythrocyte, 10, 26-fold in a yield of 51.3% by using ammonium sulphate precipitation and 2 ,5 -ADP-Sepharose 4B affinity gel. The purified enzyme showed a single band on sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE). The effects of four different antiemetics (granisetron hydrochloride, ondansetron hydrochloride, metoclopramide hydrochloride, trimethobenzamide hydrochloride) were investigated on the purified enzyme. Granisetron hydrochloride and ondansetron hydrochloride inhibited the enzyme activity (K i values; 5.05 mM and 0.034 mM, I 50 values; 3.9 mM and 0.036 mM, respectively). Metoclopramide hydrochloride, trimethobenzamide hydrochloride showed no inhibition effects.

This paper will help almost anyone with or without a chronic condition to build naturally Glutathione in their bodies though the intake of Glutathione precursors, maintainers, optimizers and recyclers. This protocol offers two options of Glutathione building: Naturally through food consumption and through supplementation.
One can also alternate between both methods in order to optimize the intake of certain key building blocks that maybe unavailable in one method versus the other due to variable factors such as cost and local availability.

■ Summary Background Rosa roxburghii (RR) is a plant of which the fruit juice has been used as a medicinal remedy for a variety of diseases. It has been proposed that the putative beneficial properties are related to its antioxidant potential. Aim of study We investigated the contribution of a supplemented RR fruit sample on the antioxidant status in a cohort of healthy humans. Methods A total of 36 young, healthy and non-smoking individuals were recruited for this randomised placebo-controlled, single-blind trial. The study was diet controlled over a five-week period with a two week run-in period before participants daily received a placebo or an encapsulated supplement of RR sample. Total antioxidant capacity, glutathione redox state, glutathione reductase, glutathione peroxidase, superoxide dismutase and 8-OHdG levels were measured. Results RR supplementation significantly increased plasma antioxidant capacity (p = 0.04) and GSH:GSSG ratios in blood (p = 0.03). No significant changes in 8-OHdG levels, total glutathione levels or antioxidant modulating enzymes were detected suggesting that the observed shift of the glutathione redox state probably occurs via the antioxidant mediated protection of GSH. Conclusions We conclude that these findings support the putative beneficial properties that have been linked to Rosa roxburghii as a dietary supplement that can enhance antioxidant status.

Pouteria campechiana (Kunth) Baehni. is used as a remedy for coronary trouble, liver disorders, epilepsy, skin disease, and ulcer. Therefore, the present study aims to investigate the antioxidant and hepatoprotective effect of polyphenolic-rich P. campechiana fruit extract against acetaminophenintoxicated rats. Total phenolic and flavonoid contents of egg fruit were estimated followed by the determination of antioxidant activities. Treatment with P. campechiana fruit extract effectively scavenged the free radicals in a concentration-dependent manner within the range of the given concentrations in all antioxidant models. The presence of polyphenolic compounds were confirmed by high-performance thin-layer chromatography (HPTLC).

The aim of this study was to investigate effect of antiemetics on G6PD and antioxidant enzymes. Antiemetics are currently being used to reduce or prevent nausea and vomiting in patients. This is the first study to show effect of antiemetics on glucose-6-phosphate dehydrogenase (G6PD) and antioxidant enzyme activities. For in vitro studies, G6PD was purified from human erythrocyte, 10, 26-fold in a yield of 51.3% by using ammonium sulphate precipitation and 2 ,5 -ADP-Sepharose 4B affinity gel. The purified enzyme showed a single band on sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE). The effects of four different antiemetics (granisetron hydrochloride, ondansetron hydrochloride, metoclopramide hydrochloride, trimethobenzamide hydrochloride) were investigated on the purified enzyme. Granisetron hydrochloride and ondansetron hydrochloride inhibited the enzyme activity (K i values; 5.05 mM and 0.034 mM, I 50 values; 3.9 mM and 0.036 mM, respectively). Metoclopramide hydrochloride, trimethobenzamide hydrochloride showed no inhibition effects.

A three-day pretreatment of olive somatic embryos (SE) with 0.75 M sucrose, combined with cryoprotection (0.5 M DMSO, 1 M sucrose, 0.5 M glycerol and 0.009 M proline) and controlled rate cooling, supported regrowth (as 34.6% fresh weight gain) and resumption of embryo development after cryopreservation. Pretreatment with mannitol or sorbitol did not support regrowth. Profiles of sugars, proline, antioxidant enzymes, Reactive oxygen species (ROS), secondary oxidation products and ethylene were constructed for the most successful (0.75 M) pretreatment series. Sucrose was the optimal pretreatment for supporting recovery, it also elevated glutathione reductase (GR) activity compared to controls, whereas superoxide dismutase (SOD), catalase and guaiacol peroxidase activities remained relatively unchanged. Superoxide dismutase activity was higher in SE pretreated with sucrose, compared with those pretreated with polyols; H 2 O 2 was enhanced in SE pretreated with sorbitol and sucrose compared to mannitol. The overall trend for ethylene and • OH production revealed their levels were highest in SE pretreated with polyols albeit, for individual treatments this was not always the case. Generally, pretreatments did not significantly change embryo secondary oxidation profiles of ThioBarbituric Acid Reactive Substances (TBARS) and Schiff's bases. In combination these studies suggest oxidative processes may influence regrowth of cryopreserved olive SE and that optimal pretreatments could, in part, increase tolerance by an overall enhancement of endogenous antioxidants (particularly GR), proline and sugars.

The hepatoprotective activity of the aqueous-methanolic extract of Ambrosia maritima was investigated against acetaminophen (paracetamol, 4-hydroxy acetanilide) induced hepatic damage. Acetaminophen at the dose of 640 mg/kg produced liver damage in rats as manifested by the significant (P B0.001) rise in serum levels of glutamate oxaloacetate transaminase (AST), glutamate pyruvate transaminase (ALT) and alkaline phosphatase (ALP) to 1178.5 9 118.05; 607.5 932.6 and 274.16 98.89 IU/l (n=10), respectively, compared with respective control values of 97.83 93.23; 46.0 93.92 and 168.67 9 7.86 IU/l. Pretreatment of rats with the plant extract (100 and 200 mg/kg) lowered significantly (PB0.001) the respective serum AST to 203.3 9 5.74 and 157.1 9 8.78 IU/l, ALT to 138.67 97.7 and 87.5 93.6 IU/l and ALP levels to 238.0 9 5.89 and 206.5 9 7.5 IU/l, respectively. Treatment of rats with acetaminophen led to a marked increase in lipid peroxidation as measured by malondialdehyde (MDA) (42%). This was associated with a significant reduction of the hepatic antioxidant system e.g. reduced glutathione (GSH) (65%), glutathione reductase (GSH-R) (35%), total glutathione peroxidase (GSH-Px) (32%) and glutathione-S-transferase (GST) (16%). These biochemical alterations resulting from acetaminophen administration were inhibited by pretreatment with A. maritima L. extract. These data suggest that the plant A. maritima L. may act as a hepatoprotective and antioxidant agent.

The role of oxidative stress has been reported in various diabetic complications. This study was undertaken to evaluate the protective effect of ginger, a medicinal plant, on the tissue antioxidant defence system and lipid peroxidative status in streptozotocin-induced diabetic rats. An increased reactive oxygen species and insufficient antioxidant activity are associated with diabetes mellitus, which is mainly responsible for diabetic pathogenesis. The role of ginger as antioxidant markers of liver and kidney were investigated. The antioxidant effect of the ginger was compared with glibenclamide, a well-known hypoglycaemic drug. The diabetic rats exhibited lower activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) and reduced glutathione (GSH) content and higher level of malondialdehyde (MDA) in hepatic and renal tissues as compared with normal rats. The activities of all parameters were found to be increased, except MDA in ginger-treated diabetic rats, in hepatic and renal tissues. Ginger supplementation, for 30 days to diabetic rats, resulted in significant dose-dependent hypoglycaemic and antioxidant activities. These findings suggest that ginger treatment exerts a therapeutic protective effect in diabetes by decreasing oxidative stress, and hepatic and renal damage.

The objective of this article was to review the biochemical basis of the total antioxidant capacity (TAC) test and its applications to exercise science and promotion of healthy aging. Measurement of TAC allows evaluation of the antioxidant content of muscle, heart and other exercise-target organs. Acute non-regular physical exercise and body exposition to higher altitude have been associated with a considerable decrease of blood TAC. However, regular practice of physical activity and exercise is associated with improved antioxidant response increasing TAC levels. TAC methodologies did not address lipophylic antioxidants and have some other limitations. However, TAC is useful as a complementary test for the evaluation of antiperoxidation assays and blood, erythrocyte and cytosolic antioxidant enzyme assays (glutathion reductase, glutathion peroxidase, superoxide dismutase and catalase). Exercise induces both molecular antioxidant and hormetic responses which have been suggested to be linked with a healthy aging.