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The WHO recommends single low-dose (SLD) primaquine as a gametocytocide to reduce Plasmodium falciparum transmission in areas of low transmission. Despite this recommendation, uptake of SLD primaquine has been low because of concerns of glucose-6-phosphate dehydrogenase (G6PD) deficiency. Individuals with G6PD deficiency can experience hemolysis when exposed to primaquine. In Southern Province, Zambia, malaria transmission has declined significantly over the past decade. Single low-dose primaquine may be an effective tool, but there is limited information on G6PD deficiency. We screened 137 residents in Macha, Southern Province, Zambia, and the prevalence of G6PD (A-) was 15%. We also revisited data collected from 2008 to 2013 in the same area and found the highest gametocyte burden among those aged 5-15 years. The findings from this study suggest that SLD primaquine targeted to school-aged children may be an effective tool to help achieve malaria elimination in southern Zambia.

Glucose-6-Phosphate Dehydrogenase (G6PD) is a ubiquitous cytoplasmic enzyme converting glucose-6-phosphate into 6-phosphogluconate in the pentose phosphate pathway (PPP). The G6PD deficiency renders the inability to regenerate glutathione due to lack of Nicotine Adenosine Dinucleotide Phosphate (NADPH) and produces stress conditions that can cause oxidative injury to photoreceptors, retinal cells, and blood barrier function. In this study, we constructed pharmacophore-based models based on the complex of G6PD with compound AG1 (G6PD activator) followed by virtual screening. Fifty-three hit molecules were mapped with core pharmacophore features. We performed molecular descriptor calculation, clustering, and principal component analysis (PCA) to pharmacophore hit molecules and further applied statistical machine learning methods. Optimal performance of pharmacophore modeling and machine learning approaches classified the 53 hits as drug-like (18) and nondrug-like (35) compounds. The drug-like compounds further evaluated our established cheminformatics pipeline (molecular docking and in silico ADMET (absorption, distribution, metabolism, excretion and toxicity) analysis). Finally, five lead molecules with different scaffolds were selected by binding energies and in silico ADMET properties. This study proposes that the combination of machine learning methods with traditional structure-based virtual screening can effectively strengthen the ability to find potential G6PD activators used for G6PD deficiency diseases. Moreover, these compounds can be considered as safe agents for further validation studies at the cell level, animal model, and even clinic setting.

Background: Endocrine disruptor such as cadmium has been widely reported to cause testicular toxicity, which contributes to recent decline in male fertility worldwide. Glutamine, the most abundant amino acid in the body has been demonstrated to exert protective effects in cellular toxicity. However, its role in testicular toxicity is unknown. The present study is therefore aimed at investigating the effects of glutamine supplementation on cadmium-induced testicular toxicity, and the possible involvement of glucose-6-phosphate dehydrogenase (G6PD) activity., Materials and Method: Male Wistar rats weighing 160-190 g were allotted into 4 groups (n = 5/group): The groups received vehicle (distilled water; p.o.), glutamine (1gkg - 1 ; p.o.), cadmium chloride (5mgkg - 1 p.o.) and Cadmium chloride plus glutamine respectively, daily for 30 days. Biochemical and histological analyses were performed with appropriate method., Results: Administration of cadmium significantly decreased body weight, sperm count, motility and viability, as well as altered sperm morphology and progressivity. Cadmium also caused atrophy of the seminiferous tubule in addition to disrupted testicular architecture, lumen, Sertoli cells and spermatogonia. Similarly, serum and testicular aspartate transaminase, and malondialdehyde significantly increased, and G6PD, glutathione, nicotinamide adenine dinucleotide phosphate and nitric oxide significantly decreased with corresponding decrease in follicle stimulating hormone, luteinizing hormone and testosterone in cadmium-treated animals compared with control groups. However, supplementation with glutamine attenuated these alterations., Conclusion: The present study demonstrates that cadmium induces testicular dysfunction that is attributable to defective G6PD and accompanied by increased lipid peroxidation and impaired NO-dependent endothelial function. Interestingly, glutamine supplementation ameliorates cadmium-induced testicular dysfunction through enhancement of G6PD activity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The regulation of lipogenesis and lipolysis mechanisms related to consumption of lipid has not been studied in swimming crab. The aims of the present study were to evaluate the effects of dietary lipid levels on growth, enzymes activities and expression of genes of lipid metabolism in hepatopancreas of juvenile swimming crab. Three isonitrogenous diets were formulated to contain crude lipid levels at 5·8, 9·9 and 15·1 %. Crabs fed the diet containing 15·1 % lipid had significantly lower growth performance and feed utilisation than those fed the 5·8 and 9·9 % lipid diets. Crabs fed 5·8 % lipid had lower malondialdehyde concentrations in the haemolymph and hepatopancreas than those fed the other diets. Highest glutathione peroxidase in haemolymph and superoxide dismutase in hepatopancreas were observed in crabs fed 5·8 % lipid. The lowest fatty acid synthase and glucose 6-phosphate dehydrogenase activities in hepatopancreas were observed in crabs fed 15·1 % lipid, whereas crabs fed 5·8 % lipid had lower carnitine palmitoyltransferase-1 activity than those fed the other diets. Crabs fed 15·1 % lipid showed lower hepatopancreas expression of genes involved in long-chain-PUFA biosynthesis, lipoprotein clearance, fatty acid uptake, fatty acid oxidation, lipid anabolism and lipid catabolism than those fed the other diets, whereas expression of some genes of lipoprotein assembly and fatty acid oxidation was up-regulated compared with crabs fed 5·8 % lipid. Overall, high dietary lipid level can inhibit growth, reduce antioxidant enzyme activities and influence lipid metabolic pathways to regulate lipid deposition in crab.

Butyl p-hydroxybenzoic acid, also known as butylparaben (BP), is one of the most common parabens absorbed by the skin and gastrointestinal tract and metabolised in the liver and kidney. Recent in vivo and in vitro studies have raised concern that BP causes reproductive, development, and teratogenic toxicity. However, BP-induced oxidative stress and its relation to tissue damage has not been widely investigated before. Therefore, we aimed to investigate the effects of butyl 4-hydroxybenzoate on enzyme activities related to the pentose phosphate pathway and on glutathione-dependent enzymes such as glucose 6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6-PGD), glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione-S-transferase (GST) in kidney, liver, brain, and testis tissues. Male rats were randomly divided into four groups to orally receive corn oil (control) or 200, 400, or 800 mg/kg/day of BP for 14 days. Then we measured G6PD, GR, GST, 6-PGD, and GPx enzyme activities in these tissues and studied histopathological changes. BP treatment caused imbalance in antioxidant enzyme activities and tissue damage in the liver, kidney, brain, and testis. These findings are the first to show the degenerative role of BP on the cellular level. The observed impairment of equivalent homeostasis and antioxidant defence points to oxidative stress as a mechanism behind tissue damage caused by BP.

Bacterial infections are known to alter glucose metabolism within tissues via mechanisms of inflammation. We conducted this study to examine whether insulin response genes are differentially expressed in gingival tissues, comparing samples from experimental gingivitis and periodontitis subjects to those from healthy individuals. Total RNA was extracted from gingival biopsies from 26 participants: 8 periodontally healthy, 9 experimental gingivitis, and 9 periodontitis subjects. Gene expression patterns were evaluated with a polymerase chain reaction array panel to examine 84 candidate genes involved with glucose metabolism, insulin resistance, and obesity. Array data were evaluated with a t test adjusted by the false discover rate (P < 0.05), and ingenuity pathway analysis was performed for statistical testing of pathways. Although tissue samples were not sufficient to enable protein quantification, we confirmed the upregulation of the key gene using lipopolysaccharide-stimulated primary gingival epithelial cells by Western blot. The mRNA expression patterns of genes that are associated with insulin response and glucose metabolism are markedly different in experimental gingivitis subjects compared with healthy controls. Thirty-two genes are upregulated significantly by at least 2-fold, adjusted for false discover rate (P < 0.05). Periodontitis subjects show similar but attenuated changes in gene expression patterns, and no genes meet the significance criteria. Ingenuity pathway analysis demonstrates significant activation of the carbohydrate metabolism network in experimental gingivitis but not in periodontitis. G6PD protein increases in response to lipopolysaccharide stimulation in primary gingival epithelial cells, which is in the same direction as upregulated mRNA in tissues. Acute gingival inflammation may be associated with tissue metabolism changes, but these changes are not evident in chronic periodontitis. This study suggests that acute gingival inflammation may induce localized changes that modify tissue insulin/glucose metabolism., (© International & American Associations for Dental Research.)

We investigated apoptotic effects and changes in glucose-6-phosphate dehydrogenase (G6PD) enzyme activity in liver and gill tissues of fish exposed to chlorpyrifos. Three different chlorpyrifos doses (2.25, 4.5 and 6.75 μg/L) were administrated to rainbow trout at different time intervals (24, 48, 72 and 96 h). Acute exposure to chlorpyrifos showed time dependent decrease in G6PD enzyme activity at all concentrations (p < 0.05). Immunohistochemical results showed that chlorpyrifos caused mucous cell loss in gill tissue and apoptosis via caspase-3 activation in fish. The present study suggested that chlorpyrifos inhibits G6PD enzyme and causes mucous cell loss in gill and apoptosis in gill and liver tissues.

We previously demonstrated that systemic oxidative stress is present in Down syndrome (DS) patients. In the present study we investigated the antioxidant status in the peripheral blood of DS children and teenagers comparing such status before and after an antioxidant supplementation. Oxidative stress biomarkers were evaluated in the blood of DS patients (n=21) before and after a daily antioxidant intervention (vitamin E 400mg, C 500 mg) during 6 months. Healthy children (n=18) without DS were recruited as control group. The activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), gamma-glutamyltransferase (GGT), glucose-6-phosphate dehydrogenase (G6PD) and myeloperoxidase (MPO), as well as the contents of reduced glutathione (GSH), uric acid, vitamin E, thiobarbituric acid reactive substances (TBARS), and protein carbonyls (PC) were measured. Before the antioxidant therapy, DS patients presented decreased GST activity and GSH depletion; elevated SOD, CAT, GR, GGT and MPO activities; increased uric acid levels; while GPx and G6PD activities as well as vitamin E and TBARS levels were unaltered. After the antioxidant supplementation, SOD, CAT, GPx, GR, GGT and MPO activities were downregulated, while TBARS contents were strongly decreased in DS. Also, the antioxidant therapy did not change G6PD and GST activities as well as uric acid and PC levels, while it significantly increased GSH and vitamin E levels in DS patients. Our results clearly demonstrate that the antioxidant intervention with vitamins E and C attenuated the systemic oxidative damage present in DS patients., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Glucose-6-phosphate dehydrogenase (G6PD) is a key enzyme in the pentose phosphate pathway and provides reducing energy to all cells by maintaining redox balance. The most common clinical manifestations in patients with G6PD deficiency are neonatal jaundice and acute hemolytic anemia. The effects of microbial infection in patients with G6PD deficiency primarily relate to the hemolytic anemia caused by Plasmodium or viral infections and the subsequent medication that is required. We are interested in studying the impact of bacterial infection in G6PD-deficient cells. G6PD knock down A549 lung carcinoma cells, together with the common pathogen Staphylococcus aureus, were employed in our cell infection model. Here, we demonstrate that a lower cell viability was observed among G6PD-deficient cells when compared to scramble controls upon bacterial infection using the MTT assay. A significant increase in the intracellular ROS was detected among S. aureus-infected G6PD-deficient cells by observing dichlorofluorescein (DCF) intensity within cells under a fluorescence microscope and quantifying this signal using flow cytometry. The impairment of ROS removal is predicted to enhance apoptotic activity in G6PD-deficient cells, and this enhanced apoptosis was observed by annexin V/PI staining under a confocal fluorescence microscope and quantified by flow cytometry. A higher expression level of the intrinsic apoptotic initiator caspase-9, as well as the downstream effector caspase-3, was detected by Western blotting analysis of G6PD-deficient cells following bacterial infection. In conclusion, we propose that bacterial infection, perhaps the secreted S. aureus α-hemolysin in this case, promotes the accumulation of intracellular ROS in G6PD-deficient cells. This would trigger a stronger apoptotic activity through the intrinsic pathway thereby reducing cell viability when compared to wild type cells.

Context and Objective: The aim of the study was to investigate whether treatment with N-acetylcysteine (NAC) is able to restore erythrocyte glutathione (GSH) content in workers exposed to lead. Additionally, we measured the leukocyte and erythrocyte activities of GSH-related enzymes, such as glutathione reductase (GR), glutathione-S-transferase (GST), and glucose-6-phosphate dehydrogenase (G6PD), and estimated the influence of NAC administration on oxidative stress intensity, which was measured as the lipofuscin (LPS) level in erythrocytes., Methods: The exposed population consisted of 171 healthy males randomly divided into four groups. Workers in the first group (n = 49) were not administered any antioxidants, drugs, vitamins, or dietary supplements, while workers in the remaining groups were treated with NAC at three doses for 12 weeks (1 × 200 mg per day, 2 × 200 mg per day, and 2 × 400 mg per day). All workers continued to work during the study. The blood of all examined workers was drawn two times: at the beginning of the study and after 12 weeks of treatment., Results and Conclusion: Blood lead levels decreased significantly in all groups receiving NAC compared to those in baseline. Erythrocyte GSH concentrations were significantly elevated in workers receiving 400 and 800 mg of NAC compared to those in baseline by 5% and 6%, respectively. Erythrocyte G6PD activity was significantly elevated in workers receiving 200, 400, and 800 mg of NAC compared to those in baseline by 24%, 14%, and 14%, respectively. By contrast, there were no significant differences in leukocyte G6PD or leukocyte and erythrocyte glutathione reductase (GR) activities before and after treatment. Leukocyte GST activities decreased significantly after treatment in workers receiving 200 mg of NAC by 34%, while LPS levels decreased significantly in workers receiving 200, 400, and 800 mg of NAC compared to those in baseline by 5%, 15%, and 13%, respectively. In conclusion, NAC decreases oxidative stress in workers exposed to lead via stimulating GSH synthesis.

In the present study, the effect of alcoholic stem extract of Gymnema montanum (GMSt) on blood glucose, plasma insulin, and carbohydrate metabolic enzymes were studied in experimental diabetes. Diabetes mellitus was induced by a single intraperitoneal injection of STZ (60 mg/kg bw). Five days after STZ induction, diabetic rats received GMSt orally at the doses of 25, 50, 100 and 200mg/kg daily for 3 weeks. Graded doses of stem extract showed a significant reduction in blood glucose levels and improvement in plasma insulin levels. The effect was more pronounced in 100 and 200mg/kg than 50mg/kg. GMSt showed significant increase in hexokinase, Glucose-6-phosphate dehydrogenase and glycogen content in liver of diabetic rats while there was significant reduction in the levels of glucose-6-phosphatase and fructose-1,6-bisphosphatase. The present study clearly indicated significant antidiabetic effect with the stem extract of G. montanum and lends support for its traditional usage., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

3',5'-cyclic guanosine monophosphate (cGMP) is an important second messenger in plants. In the present study, roles of cGMP in salt resistance in Arabidopsis roots were investigated. Arabidopsis roots were sensitive to 100 mM NaCl treatment, displaying a great increase in electrolyte leakage and Na(+)/K(+) ratio and a decrease in gene expression of the plasma membrane (PM) H(+)-ATPase. However, application of exogenous 8Br-cGMP (an analog of cGMP), H(2)O(2) or CaCl(2) alleviated the NaCl-induced injury by maintaining a lower Na(+)/K(+) ratio and increasing the PM H(+)-ATPase gene expression. In addition, the inhibition of root elongation and seed germination under salt stress was removed by 8Br-cGMP. Further study indicated that 8Br-cGMP-induced higher NADPH levels for PM NADPH oxidase to generate H(2)O(2) by regulating glucose-6-phosphate dehydrogenase (G6PDH) activity. The effect of 8Br-cGMP and H(2)O(2) on ionic homeostasis was abolished when Ca(2+) was eliminated by glycol-bis-(2-amino ethyl ether)-N,N,N',N'-tetraacetic acid (EGTA, a Ca(2+) chelator) in Arabidopsis roots under salt stress. Taken together, cGMP could regulate H(2)O(2) accumulation in salt stress, and Ca(2+) was necessary in the cGMP-mediated signaling pathway. H(2)O(2), as the downstream component of cGMP signaling pathway, stimulated PM H(+)-ATPase gene expression. Thus, ion homeostasis was modulated for salt tolerance.

Methotrexate (MTX) an antifolate drug and leucovorin its antidote, are used in the treatment of both neoplastic and non-neoplastic diseases in young women. We hypothesize that MTX treatment might comprise a deleterious effect on fast proliferating reproductive cells, an unavoidable and unwanted side effect. MTX given dose dependently to rats for 20 days prevented vaginal cyclicity and caused a reduction in serum progesterone and estradiol. External morphology of reproductive tract displayed thinning of organs and reduction in their weights. To reveal mechanism of MTX action, we examined the histology of ovary, oviduct, uterus, cervix and vagina. Results suggested that in a dose-dependent fashion MTX restrained preantral and antral follicular growth in ovary. Epithelium and stroma of oviduct, uterus, cervix and vagina were disrupted and lost their normal structures. Such alterations in ovarian function raised serum follicle stimulating hormone, luteinizing hormonal profiles. Expression of steroidogenic acute regulatory protein and P450 cholesterol side chain cleavage gene, which are both essential for steroidogenesis, markedly decreased in ovary upon MTX treatment. Total RNA, DNA and protein concentrations, glucose 6 phosphate dehydrogenase, lactate dehydrogenase and alkaline phosphatase enzyme activities in ovary were distinctly altered. Leucovorin supplementation and withdrawal of the treatment, improved MTX caused effects partially. These results for the first time indicate that the malfunction of female reproductive organs by MTX treatment in young women is not only correlated to the disrupted circulating levels of hormones and histoarchitecture of tissues but also discrepancies in steroidogenic genes and hormone regulated enzyme activities in ovary.

Objective: Growth of white adipose tissue takes place in normal development and in obesity. A pool of adipose progenitors is responsible for the formation of new adipocytes and for the potential of this tissue to expand in response to chronic energy overload. However, factors controlling self-renewal of human adipose progenitors are largely unknown. We investigated the expression profile and the role of activin A in this process., Research Design and Methods: Expression of INHBA/activin A was investigated in three types of human adipose progenitors. We then analyzed at the molecular level the function of activin A during human adipogenesis. We finally investigated the status of activin A in adipose tissues of lean and obese subjects and analyzed macrophage-induced regulation of its expression., Results: INHBA/activin A is expressed by adipose progenitors from various fat depots, and its expression dramatically decreases as progenitors differentiate into adipocytes. Activin A regulates the number of undifferentiated progenitors. Sustained activation or inhibition of the activin A pathway impairs or promotes, respectively, adipocyte differentiation via the C/EBPβ-LAP and Smad2 pathway in an autocrine/paracrine manner. Activin A is expressed at higher levels in adipose tissue of obese patients compared with the expression levels in lean subjects. Indeed, activin A levels in adipose progenitors are dramatically increased by factors secreted by macrophages derived from obese adipose tissue., Conclusions: Altogether, our data show that activin A plays a significant role in human adipogenesis. We propose a model in which macrophages that are located in adipose tissue regulate adipose progenitor self-renewal through activin A.

Background: Melatonin, found in high concentrations in the pineal gland, organs within the digestive system and in some plants and fungi, acts as an antioxidant which decreases reactive oxygen species in streptozocin-induced diabetic rats, raises insulin secretion by the pancreatic beta-cells and increases the number of insulin receptors on hepatocyte membranes., Methods: The protective and therapeutic effects of melatonin feeding in streptozocin-induced diabetic rats were studied. Streptozocin administered rats were gavaged with melatonin, pre- and post-treatment, at a level of 5 mg/kg body weight daily for a period of 15 days. Levels of plasma glucose, cholesterol, triacylglycerol, oral glucose tolerance test, and some hepatic enzymes of carbohydrate metabolism including insulin inducible glucokinase, hexokinase and glucose 6-P dehydrogenase were measured using standard methods and compared with the values in normoglycemic and diabetic control groups., Results: Both pre- and post-treatment of the streptozocin administered rats with melatonin normalized plasma glucose, cholesterol, and triacylglycerol, improved oral glucose tolerance test and increased hepatic glucokinase, hexokinase and glucose 6-P dehydrogenase specific activities to the levels seen in normal rats., Conclusion: Melatonin pre-treatment prevents the injurious effects of streptozocin in rats. In streptozocin induced diabetic animals, post-treatment with this antioxidant normalizes both blood and liver constituents which were ameliorated by streptozocin.

Tetrazolium salts such as XTT and MTT are widely used to produce formazan for cell proliferation and cytotoxicity assays through bioreductase activity. However, the XTT assay showed significant increase in MDBK cell viability when cells were treated with both 50 and 100 muM of the pro-oxidant, tert-butylhydroquinone (t-BHQ), although the crystal violet assay showed no cytotoxic effect with these concentrations, and the induction of lipid peroxidation was not observed. We investigated the mechanism of enhancement of XTT substrate reduction after treatment of MDBK cells with t-BHQ, leading to apparent increase in cell viability. t-BHQ caused an increase in absorbance at 340 nm in culture medium, suggesting that t-BHQ increases cellular production and release of NADH and/or NADPH. Although t-BHQ did not change the NADH concentration in cell culture medium, the addition of NADP(+)-dependent glutathione reductase decreased the XTT reduction to the control level, indicating cellular release of NADPH. t-BHQ also increased intracellular glucose-6-phosphate dehydrogenase activity, producing NADPH. Taken together, our findings indicate that t-BHQ treatment activates NADPH generating enzymes such as glucose-6-phosphate dehydrogenase followed by release of NADPH in the cell culture medium, resulting in direct XTT reduction by NADPH.

Background and Objective: Arecoline, an arecanut alkaloid present in the saliva of betel quid chewers, has been implicated in the pathogenesis of a variety of inflammatory oral diseases, including oral submucous fibrosis and periodontitis. To understand the molecular basis of arecoline action in epithelial changes associated with these diseases, we investigated the effects of arecoline on human keratinocytes with respect to cell growth regulation and the expression of stress-responsive genes., Material and Methods: Human keratinocyte cells (of the HaCaT cell line) were treated with arecoline, following which cell viability was assessed using the Trypan Blue dye-exclusion assay, cell growth and proliferation were analyzed using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and 5-bromo-2-deoxyuridine incorporation assays, cell cycle arrest and generation of reactive oxygen species were examined using flow cytometry, and gene expression changes were investigated using the reverse transcription-polymerase chain reaction technique. The role of oxidative stress, muscarinic acetylcholine receptor and mitogen-activated protein kinase (MAPK) pathways were studied using specific inhibitors. Western blot analysis was performed to study p38 MAPK activation., Results: Arecoline induced the generation of reactive oxygen species and cell cycle arrest at the G1/G0 phase in HaCaT cells without affecting the expression of p21/Cip1. Arecoline-induced epithelial cell death at higher concentrations was caused by oxidative trauma without eliciting apoptosis. Sublethal concentrations of arecoline upregulated the expression of the following stress-responsive genes: heme oxygenase-1; ferritin light chain; glucose-6-phosphate dehydrogenase; glutamate-cysteine ligase catalytic subunit; and glutathione reductase. Additionally, there was a dose-dependent induction of interleukin-1alfa mRNA by arecoline via oxidative stress and p38 MAPK activation., Conclusion: Our data highlight the role of oxidative stress in arecoline-mediated cell death, gene regulation and inflammatory processes in human keratinocytes.

Encapsulation of antineoplastic drugs within erythrocytes is one of the studied strategies to diminish the toxic side effects of anthracycline antibiotics. Glutaraldehyde is often used as crosslinking agent to link the drugs, including idarubicin (IDA) to the cells. The previous studies indicated that in glutaraldehyde-treated human erythrocytes the elevated level of drug was observed but also the various changes in the organization of the red cells were noted. In this study, we continue our investigations and now we concentrate on the effect of these compounds on antioxidative system in erythrocytes. We determined reactive oxygen species (ROS) production, glutathione content and alterations in the activity of enzymes responsible for maintaining glutathione in reduced form in human erythrocytes. Measurements of both reduced and total glutathione levels and the activity of glutathione reductase and glucose-6-phosphate dehydrogenase were performed spectrophotometrically. The results show that ROS were produced in erythrocytes treated with IDA and with IDA and glutaraldehyde. IDA at a concentration of 10 microg/ml did not cause any changes in total or reduced glutathione levels. When IDA-preincubated erythrocytes were treated with glutaraldehyde, significant changes in the determined parameters were observed in a glutaraldehyde concentration dependent manner. It was correlated with decreased activity of glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD). Together with the significant changes in reduced form of glutathione (GSH)/total glutathione ratio, the exposure of phosphatidylserine at the cell surface was also observed.

N-acetylaspartic acid (NAA) is the biochemical hallmark of Canavan Disease, an inherited metabolic disease caused by deficiency of aspartoacylase activity. NAA is an immediate precursor for the enzyme-mediated biosynthesis of N-acetylaspartylglutamic acid (NAAG), whose concentration is also increased in urine and cerebrospinal fluid of patients affected by CD. This neurodegenerative disorder is clinically characterized by severe mental retardation, hypotonia and macrocephaly, and generalized tonic and clonic type seizures. Considering that the mechanisms of brain damage in this disease remain not fully understood, in the present study we investigated whether intracerebroventricular administration of NAA or NAAG elicits oxidative stress in cerebral cortex of 30-day-old rats. NAA significantly reduced total radical-trapping antioxidant potential, catalase and glucose 6-phosphate dehydrogenase activities, whereas protein carbonyl content and superoxide dismutase activity were significantly enhanced. Lipid peroxidation indices and glutathione peroxidase activity were not affected by NAA. In contrast, NAAG did not alter any of the oxidative stress parameters tested. Our results indicate that intracerebroventricular administration of NAA impairs antioxidant defenses and induces oxidative damage to proteins, which could be involved in the neurotoxicity of NAA accumulation in CD patients.

Northern blot analysis and a GFP-based reporter assay showed that zwf-1, which encodes glucose-6-phosphate dehydrogenase, was highly induced when Pseudomonas putida KT2440 was cultured in minimal medium containing glucose or gluconate. However, zwf-1 expression was not detected in the presence of pyruvate or succinate. The use of a knockout mutant of HexR, a putative transcription regulator, resulted in constitutively high expression of zwf-1, regardless of the carbon source. An electrophoretic mobility shift assay showed that HexR protein binds to the zwf-1 promoter region and that HexR binding is inhibited by 2-keto-3-deoxy-6-phosphogluconate (KDPG). Despite the presence of gluconate, the edd mutant (non-KDPG producer) was not able to induce the zwf-1 gene. The eda mutant (KDPG overproducer) featured a constitutively high level of zwf-1 expression. Interestingly, zwf-1 was also highly expressed in the presence of oxidative stress-inducing reagents. The level of zwf-1 induction in wild-type cells undergoing oxidative stress did not differ significantly from that observed with the hexR mutant under normal conditions. Interestingly, the hexR mutant was more tolerant of oxidative stress than the wild-type. Expression of zwf-1 was induced by oxidative stress in the edd mutant. Thus, KDPG, a real inducer of zwf-1 gene expression, was not necessary for oxidative-stress induction. In vitro binding of HexR to its cognate promoter region was diminished by menadione and cumene hydroperoxide. The data suggested that HexR might be a dual-sensing regulator of zwf-1 induction that is able to respond to both KDPG and oxidative stress.

Ethnopharmacological Relevance: Coix seed has been traditionally used to treat cancers in folk medicine., Aim of the Study: Study the anticancer action mechanism of Coix seed extract., Materials and Methods: After the treatment with Coix seed extract (10 microl/ml), the residual activity of fatty acid synthase (FAS) as overall reaction, beta-ketoacyl reduction, enoyl reduction, and acetyl acetyl coenzyme A (AcAcCoA) reduction was separately detected at 340 nm in the UV-190 spectrophotometer. After rats were administrated Coix seed extract (2.5, 5.0, and 10.0 ml/kg) intragastrically for 10 days consecutively, activities of FAS, malate dehydrogenase (MDH), lipid protein lipase (LPL), hepatic lipase (HL), triglyceride (TG), and glucose-6-phosphate dehydrogenase (G-6-PD) in the plasma, liver and fatty tissues were determined., Results: Experiments in vitro showed that the inhibition of Coix seed extract on FAS activity was significant and dose dependent, and two active sites inhibited were beta-ketoacyl reductases (KR) and enoyl reductase (ER). Experiments in vivo showed that Coix seed extract inhibited FAS activity in the liver, and elevated LPL and HL activity in the plasma, and effected G-6-PD activity., Conclusions: The study supports that FAS is a novel target for anticancer activity, and provides a theoretical foundation for the wide application of Coix seed extract in traditional medicine.

Objectives: The relationships between alpha-tocopherol, pro-oxidant and antioxidant enzyme status, and radiation toxicity were studied in stage II, III, and IVA oral squamous cell carcinoma patients. The low levels of malondialdehyde and increased activities of antioxidant enzymes were correlated with decreased oxidative stress by alpha-tocopherol in oral cancer patients treated with radiotherapy. The objective of the present study was to evaluate the effect of alpha-tocopherol on oxidant-antioxidant enzyme status in oral squamous cell carcinoma patients treated with radiotherapy., Materials and Methods: The study included three groups with histologically confirmed oral squamous cell carcinoma patients (untreated), and they were further divided into two groups, viz., one consisting of patients who underwent radiotherapy alone (radiotherapy was given at the dosage of 6000 cGy in five fractions per week for a period of 6 weeks); and the other group treated with radiotherapy plus alpha-tocopherol supplementation (alpha-tocopherol was supplemented at a dosage of 400 IU/day) for the entire period of radiotherapy., Results: A significant decrease ( P < 0.001) in malondialdehyde levels and increase in activities of antioxidant enzymes ( P < 0.001) in hemolysate were noticed in patients treated with radiotherapy and simultaneously supplemented with alpha-tocopherol when compared to radiation-treated patients., Conclusion: It was seen that alpha-tocopherol played a role in protecting against the damage caused by irradiation in oral squamous cell carcinoma patients treated with radiotherapy, by enhancing the antioxidant enzyme status and reducing the pro-oxidant status.

Enhanced oxidative stress and impairments in nitric oxide synthesis and bioavailability are of considerable importance in the pathogenesis of diabetic vascular diseases. The aim of the present work was to evaluate the metabolic effects of pharmacological doses of the melatonin, a known antioxidant, on streptozotocin-induced diabetic damage in rats. We investigated the indolamine's influence on the cellular redox-balance, nitric oxide (NO) level, and the activities of antioxidative defence enzymes, as well as the activities of enzymes involved in phase II detoxication and NADPH-generating pentose phosphate pathway. Blood glucose, glycated hemoglobin, bilirubin, as well as plasma alanine aminotransferase activities increased and body weight was reduced in rats with streptozotocin-induced (60 mg/kg, i.p.) diabetes (25 days). The NO level was markedly increased in diabetic plasma (by 50%) and aortic tissue (by 30%). The hyperglycemia resulted in reduced activities of glutathione peroxidase (by 25%), catalase (by 20%), glucose-6-phosphate dehydrogenase (by 55%) and transketolase (by 40%) in liver tissue of diabetic animals. Melatonin treatment (10 mg/kg, 18 days) did not influence the level of hyperglycemia or glycated hemoglobin and it had little effect on the activities of antioxidative enzymes. However, melatonin markedly reversed the activities of glucose-6-phosphate dehydrogenase and transketolase in liver tissue of diabetic rats. The most pronounced effect of the melatonin administration was the prevention of an increase in nitric oxide levels in blood plasma and aortic tissue during diabetes. In in vitro experiments, nitrosomelatonin formation in the presence of nitrosodonors was observed. This implies that melatonin might operate as an NO scavenger and carrier. Thus, melatonin treatment may have some beneficial effects in controlling diabetic vascular complications.

Inhibitory effects of some drugs on hepatic glucose 6-phosphate dehydrogenase from Lake Van fish (chalcalburnus tarischii pallas, 1811) were investigated. For this purpose, initially liver glucose 6-phosphate dehydrogenase was purified 899-fold in a yield of 46.24% by using 2',5'-ADP Sepharose 4B affinity gel. In order to control the purification of enzyme was done SDS polyacrylamide gel electrophoresis. SDS polyacrylamide gel electrophoresis showed a single band for enzyme. A constant temperature (+4 degrees C) was maintained during the purification process. Enzyme activity was determined with the Beutler method by using a spectrophotometer at 340 nm. Vankomycine, sulfanylamide, sulfanylacetamide, nidazole, ciprofloxacin, amoxicillin and KMnO(4) were used as drugs. These drugs exhibited inhibitory effects on the enzyme. IC(50) values of vankomycine, sulfanylamide, sulfanylacetamide, nidazole, ciprofloxacin, amoxicillin and KMnO(4) were 1.88, 0.037, 0.032, 1.178, 2.26, 643.5 and 0.0002 mM, and the K(i) constants 1.18+/-0.148, 0.119+/-0.021, 0.075+/-0.015, 1.15+/-0.21, 7.69+/-0.67, 1007+/-69, and 0.001+/-0.00022 mM, respectively. While vankomycine and nidazole showed competitive inhibition, others displayed noncompetitive inhibition. K(i) constants and IC(50) values for drugs were determined by Lineweaver-Burk graphs and plotting activity percentage versus [I], respectively.

Objectives: Methacrylic compounds such as 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA) and bisphenol A glycerolate (1 glycerol/phenol) dimethacrylate (Bis-GMA) are largely present in auto- or photopolymerizable composite resins. Since the polymerization reaction is never complete, these molecules are released into the oral cavity tissues and biological fluids where they could cause local adverse effects. The aim of this work was to verify the hypothesis that the biological effects of HEMA, TEGDMA and Bis-GMA - at a non-cytotoxic concentration - depend on the interaction with mitochondria and exert consequent alterations of energy metabolism, GSH levels and the related pathways in human promyelocytic cell line (HL-60)., Methods: The biological effects of methacrylic monomers were determined by analyzing the following parameters: GSH concentration, glucose-6-phosphate dehydrogenase (G6PDH) and glutathione reductase (GR) activity, oxygen and glucose consumption and lactate production along with cell differentiation and proliferation., Results: All monomers induced both cellular differentiation and decrease in oxygen consumption. Cells treated with TEGDMA and Bis-GMA showed a significant enhancement of glucose consumption and lactate production. TEGDMA and HEMA induced GSH depletion stimulating G6PDH and GR activity., Conclusions: All the monomers under study affect the metabolism of HL-60 cells and show differentiating activity. Since alterations in cellular metabolism occurred at compound concentrations well below cytotoxic levels, the changes in energy metabolism and glutathione redox balance could be considered as potential mechanisms for inducing clinical and sub-clinical adverse effects and thus providing useful parameters when testing biocompatibility of dental materials.

Gemfibrozil is a lipid-regulating agent widely used in patients at risk of coronary disease. Pharmaceutical products, such as gemfibrozil, are found in municipal effluents and represent a major source of contamination. To date, there is little available information about the adverse effects of gemfibrozil in aquatic organisms. For this reason, the toxic effects were investigated using model systems from four trophic levels. The most sensitive system was the immobilization of Daphnia magna, with a non-observed adverse effect level of 30 microM and a mean effective concentration of 120 microM after 72 h, followed by the inhibition of bioluminescence of Vibrio fischeri, the hepatoma fish cell line PLHC-1 line and the inhibition of the growth of Chlorella vulgaris. Although protein content, neutral red uptake, methylthiazol metabolization and lysosomal function were reduced in PLHC-1 cells, stimulations were observed for lysosomal function, metallothionein levels and succinate dehydrogenase, glucose-6-phosphate dehydrogenase and acetylcholinesterase activities. No changes were observed in ethoxyresorufin-O-deethylase activity. The main morphological alterations were hydropic degeneration and loss of cells. Modulation studies on gemfibrozil toxicity were also carried out. General antioxidants and calcium chelators did not modify the toxicity of gemfibrozil, whereas a Fe(III) chelator, a membrane permeable sulphydryl-protecting compound and glutathione level modifying agents did change the toxicity. One of the possible mechanisms of gemfibrozil toxicity seems to be the binding to sulphydryl groups, including those of glutathione. According to the result, gemfibrozil should be classified as harmful to aquatic organisms. However, comparing the concentrations in water and the toxicity quantified in the assayed systems, gemfibrozil is not expected to represent acute risk to the aquatic biota.

Treatment of E. coli extract with iron/ascorbate preferentially inactivated NADP-isocitrate dehydrogenase without affecting glucose-6-phosphate dehydrogenase. NADP-Isocitrate dehydrogenase required divalent metals such as Mg(2+), Mn(2+ )or Fe(2+) ion. Iron/ascorbate-dependent inactivation of the enzyme was accompanied with the protein fragmentation as judged by SDS-PAGE. Catalase protecting the enzyme from the inactivation suggests that hydroxyl radical is responsible for the inactivation with fragmentation. TOF-MS analysis showed that molecular masses of the enzyme fragments were 36 and 12, and 33 and 14 kDa as minor components. Based on the amino acid sequence analyses of the fragments, cleavage sites of the enzyme were identified as Asp307-Tyr308 and Ala282-Asp283, which are presumed to be the metal-binding sites. Ferrous ion bound to the metal-binding sites of the E. coli NADP-isocitrate dehydrogenase may generate superoxide radical that forms hydrogen peroxide and further hydroxyl radical, causing inactivation with peptide cleavage of the enzyme. Oxidative inactivation of NADP-isocitrate dehydrogenase without affecting glucose 6-phosphate dehydrogenase shows only a little influence on the antioxidant activity supplying NADPH for glutathione regeneration, but may facilitate flux through the glyoxylate bypass as the biosynthetic pathway with the inhibition of the citric acid cycle under aerobic growth conditions of E. coli.

Purpose: To evaluate the potential of the vitamin E compound alpha-tocotrienol as antifibrotic agent in vitro., Methods: Using human Tenon's capsule fibroblast cultures, the antiproliferative and cytotoxic effects of the different vitamin E forms alpha-tocopherol, alpha-tocopheryl acetate, alpha-tocopheryl succinate and alpha-tocotrienol were compared with those of mitomycin C. To mimic subconjunctival and regular oral application in vivo, exposure time of serum-stimulated and serum-restimulated fibroblasts (SF and RF, respectively) to vitamin E forms was set at 6 days. Cultures were only exposed for 5 min to mitomycin C due to its known acute toxicity and to mimic the short-time intraoperative administration. Proliferation (expressed as % of control) was determined by DNA content quantification on days 2, 4 and 6, whereas cytotoxicity was assessed by cell morphology and glucose 6-phosphate dehydrogenase (G6PD) release after 24 h., Results: alpha-Tocopherol and alpha-tocopheryl acetate stimulated growth of SF, but not RF. Reduction of fibroblast content by alpha-tocopheryl succinate was accompanied by increased G6PD release and necrosis. Contrary to alpha-tocopheryl succinate, 50 microM or repeatedly 20 microM of alpha-tocotrienol significantly inhibited proliferation without causing cellular toxicity (maximal effect: 46.8%). RF were more sensitive to this effect than SF. Mitomycin C 100-400 microg/ml showed a stronger antiproliferative effect than alpha-tocotrienol (maximal effect: 13.8%). Morphologic characteristics of apoptosis were more commonly found under treatment with mitomycin C., Conclusions: Of the vitamin E forms tested, only alpha-tocotrienol significantly inhibited growth at non-toxic concentrations. In this in vitro study, antiproliferative effects of mitomycin C were stronger than those of alpha-tocotrienol.

Several model systems were employed to assess indirect effects that occur in the process of using radiation inactivation analysis to determine protein target sizes. In the absence of free radical scavengers, such as mannitol and benzoic acid, protein functional unit sizes can be drastically overestimated. In the case of glutamate dehydrogenase, inclusion of free radical scavengers reduced the apparent target size from that of a hexamer to that of a trimer based on enzyme activity determinations. For glucose-6-phosphate dehydrogenase, the apparent target size was reduced from a dimer to a monomer. The target sizes for both glutamate dehydrogenase and glucose-6-phosphate dehydrogenase in the presence of free radical scavengers corresponded to subunit sizes when determinations of protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or immunoblotting were done rather than enzyme activity. The free radical scavengers appear to compete with proteins for damage by secondary radiation products, since irradiation of these compounds can result in production of inhibitory species. Addition of benzoic acid/mannitol to samples undergoing irradiation was more effective in eliminating secondary damage than were 11 other potential free radical scavenging systems. Addition of a free radical scavenging system enables more accurate functional unit size determinations to be made using radiation inactivation analysis.

The ability of zinc to mobilize defense against reactive oxygen species (ROS) and H2O2-induced apoptosis was studied using a primary culture of rainbow trout gill cells. Gill cells were pretreated for 24 h with 100 microM ZnSO4 followed by 24-h exposure to 100 or 200 microM H2O2, or were subjected to 100 microM ZnSO4 together with 100 or 200 microM H2O2. Metallothionein-A (MTA) and metallothionein-B (MTB) mRNA levels were increased after treatment with zinc or H2O2, separately or in combination. Similarly, mRNA for glutathione S-transferase (GST) and glucose 6-phosphate dehydrogenase (G6PD) were increased in response to either zinc or H2O2, or after sequential treatments with zinc followed by H2O2. The stimulatory effects of zinc or H2O2 on MTA, MTB, GST, and G6PD mRNA levels could be blocked by addition of the membrane permeable zinc chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), suggesting that H2O2-induced upregulation of these genes is zinc-dependent. Pretreatment with zinc protected the cells from subsequent cell damage and apoptosis, as assessed by lactate dehydrogenase leakage, mitochondrial dehydrogenase activity (MTT assay), caspase-3 activity, and DNA fragmentation. In contrast, when gill cells were coincubated with zinc and H2O2 at the same time, H2O2 toxicity was higher than after treatment with H2O2 alone. It is concluded that zinc had a direct pro-oxidant effect when administered together with H2O2, but that pretreatment of zinc inhibited cytotoxicity and apoptosis through an indirect antioxidant action. We propose that the antioxidant action is manifested through zinc-dependent expression of several genes encoding antioxidant proteins (e.g., MTA, MTB, G6PD, and GST). Furthermore, the apparent zinc-dependency of H2O2-induced expression of antioxidant genes suggests that zinc might act as a physiological signal to mediate the response to oxidative stress.

The objective was to investigate glucose-6-phosphate dehydrogenase (G6PD) activity in monolayer cultures of thyroid epithelial cells and to examine whether inhibition of nitric oxide synthase affects activity of G6PD or oxygen sensitivity of the assay. Primary cultures without TSH addition prior to experiments demonstrated a TSH-dependent increase in G6PD activity. G6PD activity was higher in F12 medium than in a serum-free physiological medium. Secondary cultures grown in F12 medium demonstrated a diminished activity of G6PD and a lack of response to TSH. In the serum-free physiological medium, G6PD activity was comparable to that found in primary cultures and a response to high concentrations of TSH was maintained. In primary cultures grown in F12 medium devoid of TSH, G6PD activity decreased dose-dependently when nitric oxide synthase activity was inhibited. The oxygen sensitivity of the assay was comparable to that reported previously in malignant cells and correlated with the activity of G6PD in primary cultures. We suggest that thyroid epithelial cells may be an appropriate system to investigate oxygen sensitivity of the G6PD assay as the cells demonstrate a reduced oxygen sensitivity which can be influenced by culture conditions.

The SoxR protein of Escherichia coli responds to redox signals by activating the transcription of soxS, which encodes another transcription activator that directly stimulates oxidative stress genes. In contrast, Pseudomonas aeruginosa has an open reading frame (ORF) encoding a putative protein homologous to E. coli SoxR, but not to SoxS. Instead of a soxS homolog, ORFs encoding an unknown hypothetical protein and soxR are arranged divergently with their 5' ends separated by a 78 bp region containing a sequence homologous to the SoxR-binding soxS promoter. In this study, we report the overproduction and purification of SoxR from P. aeruginosa to investigate the mechanism of gene activation by SoxR. The spectroscopic properties of the purified SoxR protein indicate that it contains a redox active iron-sulfur [2Fe-2S] cluster. Redox titration of the SoxR protein revealed a midpoint potential of -290 mV. The SoxR protein specifically binds a fragment of the SoxS promoter-like region in a concentration-dependent fashion, as shown by both gel mobility shift and fluorescence polarization assays. The purified SoxR stimulates the in vitro transcription of the gene encoding the hypothetical protein in P. aeruginosa. This activity was lost following reduction of the SoxR [2Fe-2S] clusters. The levels of mRNA in the hypothetical protein increased in paraquat-treated cells. These results indicate that P. aeruginosa SoxR is a direct transcriptional activator of the hypothetical protein, and suggest that SoxR proteins may play multiple regulatory roles as a transcription factor in addition to its protective role in oxidative stress.

The crude root-peel extract of Flemingia vestita, containing genistein as the major isoflavone, has a vermifugal/vermicidal effect. It acts by causing flaccid paralysis accompanied by alterations in the activities of several tegumental enzymes and other metabolic activities in the fowl tapeworm, Raillietina echinobothrida. To elucidate the mode of action of the putative phytochemicals on energy metabolism, crude root-peel extract, pure genistein and praziquantel were tested on glucose 6-phosphate dehydrogenase (G6PDH) and enzymes of gluconeogenesis--pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK) and fructose 1,6-bisphosphatase (FBPase)--in R. echinobothrida. The activities of G6PDH, PEPCK and FBPase were largely restricted to the cytosolic fraction, while PC was confined to the mitochondrial fraction. Following treatments, the G6PDH activity was decreased by 23-31%, whereas the activities of PC and PEPCK were increased by 32-44% and 44-49%, respectively. There was no significant effect by any of the treatments on FBPase activity. We hypothesize that the phytochemicals from F. vestita, genistein in particular, influence the key enzymes of these pathways, which is perhaps a function of high energy demand of the parasite under anthelmintic stress.

The in vivo effects of N-acetyl cysteine (NAC), S-allyl cysteine, S-ethyl cysteine (SEC), S-methyl cysteine (SMC), and S-propyl cysteine (SPC) against hyperlipidemia development and oxidation stress in Balb/cA mice consuming a high saturated fat diet were examined. The influence of these agents on plasma levels of glucose, insulin, uric acid, TG, cholesterol, and the activity of three lipogenic enzymes--glucose-6-phosphate dehydrogenase, malic enzyme, and FA synthase--was determined. All mice consumed the coconut oil-basd, high saturated fat diet, water, and cysteine or one of the five cysteine-containing compounds for 4 wk. The diet with 18% saturated fat significantly elevated the activity of three lipogenic enzymes and significantly increased TG and cholesterol biosynthesis in plasma and liver (P < 0.05). When compared with the water and cysteine groups, the treatments from five cysteine-containing agents significantly reduced high saturated fat diet-increased malic enzyme and FA synthase activities, and significantly lowered TG levels in plasma and liver (P< 0.05); however, only NAC, SAC, and SMC treatments significantly reduced cholesterol levels in plasma and liver (P < 0.05). The five cysteine-containing agents significantly restored high saturated fat diet-decreased glutathione peroxidase (GPX) activity in liver (P< 0.05); however, only SMC and SPC significantly restored GPX activity in heart and kidney (P< 0.05). These agents also significantly improved high saturated fat diet-related hyperglycemia, hyperuricemia, and oxidation stress (P < 0.05). These data support the hypothesis that these compounds are potential multiply-protective agents for hyperlipidemia prevention or therapy.

In this experimental study, the effect of fish n-3 fatty acids was studied on the some important enzymes of carbohydrate metabolism, hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH) in rat liver. Wistar albino rats of experimental group (n= 9) were supplemented fish omega-3 fatty acids (n-3 PUFA) as 0.4 g/kg bw. by gavage for 30 days in addition to their normal diet. Isotonic solution was given to the control group (n= 8) by the same way. At 30th day, the rats were killed by decapitation under ether anesthesia, autopsied and liver was removed. Spectrophotometric methods were used to determine the activities of above-mentioned enzymes in the liver. The n-3 PUFA caused increases in the activities of HK, G6PD, LDH, and MDH in comparison with control. These increases were statistically significant (P < 0.01) except 6PGD activity. As a result, n-3 PUFA may regulate the metabolic function of liver effectively by increasing HK, G6PD, 6PGD, LDH, and MDH enzyme activities of rat liver when added in enough amounts to the regular diet.

Actoprotecting properties ofbemitil, tietasol in combination with atropin were studied in red cell membranes and lipid peroxidation of rats poisoned with MI in a dose 320 mg/kg (0.9 LD50). Atropin treatment showed a low effect. The addition of bemitil and tietasol normalized electric charge and osmotic resistance in red cell membranes, activity of superoxide dismutase, catalase, glucose-6-phosphate dehydrogenase and content of lipid peroxidation products--ketodienes and TBA-reacting products. Efficacy of the combined treatment is due primarily to noncholinergic mechanism of action of bemitil and tietasol--stimulation of endogenic antioxidant systems of erythron and antiradical activity (bemitil).

In the present study, the glutathione redox system was evaluated as a function of age in rat heart and muscle. A decline in reduced glutathione (GSH) levels is associated with aging and many age-related diseases. The objective of this study was to determine whether L-carnitine and DL-alpha-lipoic acid could compensate for GSH depletion in protection against oxidative insults. In this study we determined reduced glutathione, oxidized glutathione (GSSG), glutathione peroxidase (GPx), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PDH) in skeletal muscle and heart of young and aged rats. We also calculated GSH/GSSG molar ratio and glutathione redox system. GSH levels were significantly lowered in aged rats than young rats. Conversely, GSSG levels were significantly high in aged rats. GSH/GSSG molar ratio and redox index were found to decreased in aged rats. The activities of GPx, GR, and G6PDH were found to be decreased in aged rats when compared with young rats. Supplementation of carnitine and lipoic acid to aged rats significantly increased the GSH levels thereby increasing the activity of GPx, GR, and G6PDH in skeletal muscle and heart of aged rats. In conclusion, our study suggests that supplementation of carnitine and lipoic acid to aged rats improves the glutathione redox system.

Accumulation of trehalose has been implicated in the tolerance of yeast cells to several forms of stress, including heat-shock and high ethanol levels. However, yeast lacking trehalase, the enzyme that degrades trehalose, exhibit poor survival after exposure to stress conditions. This suggests that optimal cell viability also depends on the capacity to rapidly degrade the high levels of trehalose that build up under stress. Here, we initially examined the effects of trehalose on the activity of an important antioxidant enzyme, glutathione reductase (GR), from Saccharomyces cerevisiae. At 25 degrees C, GR was inhibited by trehalose in a dose-dependent manner, with 70% inhibition at 1.5M trehalose. The inhibition was practically abolished at 40 degrees C, a temperature that induces a physiological response of trehalose accumulation in yeast. The inhibition of GR by trehalose was additive to the inhibition caused by ethanol, indicating that enzyme function is drastically affected upon ethanol-induced stress. Moreover, two other yeast enzymes, cytosolic pyrophosphatase and glucose 6-phosphate dehydrogenase, showed temperature dependences on inhibition by trehalose that were similar to the temperature dependence of GR inhibition. These results are discussed in terms of the apparent paradox represented by the induction of enzymes involved in both synthesis and degradation of trehalose under stress, and suggest that the persistence of high levels of trehalose after recovery from stress could lead to the inactivation of important yeast enzymes.

An experiment was conducted with rats to investigate the effect of dietary oxidized cholesterol on the antioxidant status. Four groups of male, growing Sprague-Dawley rats received diets containing unoxidized or oxidized cholesterol (5 g/kg diet) with either coconut oil or salmon oil as dietary fat (100 g/kg diet) for 5 weeks. The oxidized cholesterol preparation consisted of 7 g of various cholesterol oxidation products and 93 g of unmodified cholesterol per 100 g preparation. No significant amounts of oxysterols were detected in the unoxidized cholesterol-supplemented diets. As parameters of the antioxidant status activities, mRNA concentrations of several antioxidative enzymes and the concentrations of glutathione were measured. Rats fed the diets containing oxidized cholesterol had significantly higher mRNA concentrations of glutathione peroxidase (p < 0.001) and superoxide dismutase (p < 0.01), a significantly higher activity of glutathione peroxidase (p < 0.001), and significantly lower concentrations of total (p < 0.05) and reduced glutathione (p < 0.01) in the liver than rats fed diets containing unoxidized cholesterol. These effects were independent of the dietary fat. In conclusion, the study suggests that dietary oxidized cholesterol stresses the antioxidant defense system in rats.

The aim of this study was to determine the effect of administration of estradiol (E2), progesterone (P4), and combination of estradiol and progesterone (EP) in aging female rats. The changes in the activities of hexokinase (HK), glucose-6-phosphatase (G6P'tase) and glucose-6-phosphate dehydrogenase (G6PDH) enzymes, and in protein levels in tissues of rats namely brain (cerebral hemisphere), heart, liver, kidney and uterus have been measured in different age groups. The random blood sugar level was measured in serum and liver. The different age groups of rats were given 0.1 microg/g body weight estradiol, 2.5 microg/g body weight progesterone and a similar concentration of both in a combined treatment for 1 month. This dose was selected after determining estrogen and progesterone levels in 3 month adult female animals so that the aging female animals had circulating hormone levels nearly the same as those of young female animals. The random sugar level was determined in serum and liver cytosolic fractions, and it was increased by combination treatment. The protein content in tissues showed significant changes only with combined hormone administration when compared with age-matched controls. The activity of HK decreased in aged animals and significantly increased by hormone treatments in all the tissues of the aged rats studied. The activity of G6P'tase increased with age up to 1.5 years and decreased in 2 years. Treatment with E2 and EP further decreased the activity significantly in all the tissues. G6PDH showed a similar pattern as was observed in HK in all the age groups. Therefore, the E2 and EP treatments caused an entire series of growth-related responses, including an increased uptake of glucose, increased the protein level in the tissues of aging rats, thereby reducing the risk factors associated with aging by normalizing hormone levels which decreased with aging and resulted in diseases such as Alzheimer's diseases and diabetes.

We reported that melatonin prevents the progression of carbon tetrachloride (CCl4)-induced acute liver injury in rats possibly by attenuating enhanced lipid peroxidation and reduced glutathione depletion. Herein, we examined the effect of melatonin on the changes in hepatic reactive oxygen species (ROS) metabolism in rats with a single intraperitoneal injection of CCl4 (1.6 g/kg body weight); the intent was to clarify the therapeutic mechanism of the indoleamine on CCl4-induced acute liver injury. Rats with and without CCl4 treatment received a single oral dose of melatonin (10, 50 or 100 mg/kg body weight) 6 hr after CCl4 treatment. Hepatic concentrations of ascorbic acid (ASC) and vitamin E (VE) and hepatic activities of superoxide dismutase (SOD), catalase (CAT), Se-glutathione peroxidase (Se-GSH-Px), glutathione reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and xanthine oxidase (XO) were determined 6 and 24 hr after CCl4 treatment. The liver of CCl4-treated rats showed reductions in ASC concentrations, and SOD activity and an increase in G-6-PDH activity at 6 hr after treatment and further decreases in ACS concentrations and SOD activity and also further increase in G-6-PDH activity in addition to decreases in CAT and GSSG-R activities and increases in VE concentrations and XO activity at 24 hr after treatment. Melatonin attenuated the reductions in hepatic ASC concentrations and SOD, CAT and GSSG-R activities and the increase in hepatic XO activity in a dose-dependent manner without affecting either hepatic Se-GSH-Px activity or the increased hepatic VE concentration and G-6-PDH activity at 24 hr after CCl4 treatment. No dose of melatonin influenced hepatic ACS and VE concentrations and SOD, CAT, Se-GSH-Px, G-6-PDH, and XO activities in CCl4-untreated rats. These results indicate that melatonin postadministered at pharmacological doses prevents the disruption of hepatic ROS metabolism associated with ASC, SOD, CAT, GSSG-R, and XO, in addition to reduced glutathione, in CCl4-treated rats.

Activated phagocytes employ myeloperoxidase to generate glycolaldehyde, 2-hydroxypropanal, and acrolein. Because alpha-hydroxy and alpha,beta-unsaturated aldehydes are highly reactive, phagocyte-mediated formation of these products may play a role in killing bacteria and tumor cells. Using breast cancer cells, we demonstrate that glycolaldehyde inactivates glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, and Cu,Zn superoxide dismutase, suppresses cell growth, and induces apoptosis. These results suggest that glycolaldehyde might be an important mediator of neutrophil anti-tumor activity.

Ciprofloxacin has been associated with several side effects including interstitial nephritis and hemolytic anemia. The combination of both side effects is extremely rare. In this report, we describe a case of ciprofloxacin-induced interstitial nephritis and autoimmune hemolytic anemia. Hemolytic anemia improved after stopping the drug and initiation of steroid therapy. Unfortunately, acute interstitial nephritis was irreversible and the patient developed end-stage renal disease.

The present study examined the effect of long-term treatment with cortisol and corticosterone on enzymes of intermediary metabolism, namely malic enzyme (ME), glucose-6-phosphate dehydrogenase (G6PDH), isocitrate dehydrogenase (ICDH), glucose 6 phosphatase (G-6-Pase), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in Oreochromis mossambicus. Cortisol and corticosterone regulate intermediary metabolism in the liver of O. mossambicus as evidenced by changes in the activity pattern of gluconeogenic and lipogenic enzymes and amino-transferases. The long-term in vivo ip administration of glucocorticoids (GCs) suggests hyperglycemic, gluconeogenic, and antilipogenic roles of the hormones in O. mossambicus. The genomic mode of action of GCs is well established in the present study since the long-term treatment is sensitive to the action of transcription and translation inhibitors.

Unlabelled: Adriamycin (ADR), which is widely used in the treatment of various neoplastic conditions, exerts toxic effects in many organs. The present study was designed to investigate the effect of lipoic acid (LA) against acute ADR induced peroxidative damages in rat kidney. The study was carried out with adult male albino rats of Wistar strain, which comprised of one control and three experimental groups. Group I rats served as controls. Group II rats received ADR (7.5mg/kg body weight) intravenously through the tail vein. Group III rats were given LA (75 mg/kg body weight) intraperitoneally. Group IV rats were given LA one day before the administration of ADR. Rats subjected to ADR administration showed a decline in the thiol capacity of the cell accompanied by high malondialdehyde (MDA) levels along with lowered activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) glutathione (GSH) and GSH metabolizing enzymes (glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD)). However no significant change was observed in the activity of glutathione-S-transferees (GST). Pretreatment with LA showed considerable changes over oxidative stress parameters. Nephrotoxic damage was evident from the decrease in the activities of gamma-glutamyl transferase (gamma-GT) and beta-glucuronidase (beta-GLU), which were reverted upon LA pretreatment., Conclusion: This study has highlighted the beneficial effects of LA pretreatment in reversing the damages caused by ADR, by bringing about an improvement in the reductive status of the cell.

Purpose: To investigate the in vitro effects of gentamicin sulfate, vancomycin hydrochloride, sodium cefazolin and ceftriaxone on glucose 6-phosphate dehydrogenase enzyme (G6PD) purified from sheep lenses., Methods: G6PD was purified from sheep lenses with a yield of 66.8% and a specific activity of 7.8 U/mg proteins, and 10,400-fold using ammonium sulfate fractionation and 2',5'-ADP Sepharose 4B affinity gel. The enzyme activity was determined by Beutler's method., Results: Gentamicin sulfate and vancomycin hydrochloride strongly inhibited the enzyme in vitro. The concentrations causing 50% inhibition (IC50 were 15.34, and 8.0 mM, respectively. Conversely, cefazolin sodium strongly activated this enzyme, and ceftriaxone caused milder activation., Conclusions: If a patient with G6PD deficiency requires gentamicin sulfate or vancomycin hydrochloride, routine ophthalmic did not inhibit this enzyme. Postmortem studies are now needed to investigate the activity of G6PD and how it is affected by these antibiotics.

Allium species such as onions and garlic are used as foodstuff, condiment, flavoring, and folk medicine. Onions may decrease hyperlipidemia and improve atherosclerosis. However, the ingredients in onion that are responsible for this phenomenon are not known. In the present study, we investigated the effects of cycloalliin, a sulfur-containing imino acid in onions, on lipid metabolism in Sprague-Dawley rats. When supplemented at the 0.1% and 0.3% levels to the atherogenic diet, cycloalliin reduced serum triacylglycerol (TAG) concentration by approximately 40% compared to the control. Serum cholesterol ester level also showed a tendency to decrease in cycloalliin groups. Hepatic lipid levels were comparable among the groups, although TAG and phospholipid contents were slightly higher in both cycloalliin groups. Dietary cycloalliin had no significant effect on hepatic enzyme activities responsible for TAG synthesis (phosphatidate phosphohydrolase, malic enzyme, and glucose-6-phosphate dehydrogenase (G6PDH)). In conclusion, dietary cycloalliin has serum TG-lowering effect without affecting hepatic TAG synthesis and content in rats, suggesting an alteration of lipoprotein assembly and secretion processes in the liver.

Deformability and activity of the enzymes: acetylcholinesterase (AChE) and dehydrogenase glucose-6-phosphate (G-6-PD), were assayed for RBC enriched in immature reticulocytes. Reticulocytosis was evoked by administration of two different drugs: recombinant human erythropoietin (rHuEPO) and phenylhydrazine (PHZ) to two groups of Wistar rats. After treatment with the former compound, a group of animals exhibited 17.33% reticulocytes in blood whereas a group of rats treated with the latter drug reached 57.66% of these cells in blood. A marked decrease in RBC deformability was found in both groups of animals. AChE did not significantly change activity neither in PHZ-treated nor in rHuEPO-treated rats, whereas G-6-PD activity was significantly decreased in the PHZ-treated group.

Dehydroepiandrosterone (DHEA) is a naturally occurring steroid synthesized in the adrenal cortex, gonads, brain, and gastrointestinal tract, and it is known to have chemopreventive and anti-proliferative actions on tumors. These effects are considered to be induced by the inhibition of glucose-6-phosphate dehydrogenase (G6PD) and/or HMG-CoA reductase (HMGR) activities. The present study was undertaken to investigate whether endogenous DHEA metabolites, i.e. DHEA-sulfate, 7-oxygenated DHEA derivatives, androsterone, epiandrosterone, and etiocholanolone, have anti-proliferative effects on cancer cells and to clarify which enzyme, G6PD or HMGR, is responsible for growth inhibition. Growth of Hep G2, Caco-2, and HT-29 cells, evaluated by 3-[4,5-dimethylthiazol]-2yl-2,5-diphenyl tetrazolium bromide (MTT) and bromodeoxyuridine incorporation assays, was time- and dose-dependently inhibited by addition of all DHEA-related steroids we tested. In particular, the growth inhibition due to etiocholanolone was considerably greater than that caused by DHEA in all cell lines. The suppression of growth of the incubated steroids was not correlated with the inhibition of G6PD (r=-0.031, n=9, NS) or HMGR (r=0.219, n=9, NS) activities. The addition of deoxyribonucleosides or mevalonolactone to the medium did not overcome the inhibition of growth induced by DHEA or etiocholanolone, while growth suppression by DHEA was partially prevented by the addition of ribonucleosides. These results demonstrate that endogenous DHEA metabolites also have an anti-proliferative action that is not induced by inhibiting G6PD or HMGR activity alone. These non-androgenic DHEA metabolites may serve as chemopreventive or anti-proliferative therapies.