Erythrocyte Glutathione S-transferase Activity Research Articles

Antioxidant and metabolic adjunctive treatment in late onset psychosis

IntroductionBasing on our previous findings of significant additional gain obtained from usage of adjunctive antioxidant medicine added to antipsychotic+antidepressant therapy in late-onset schizophrenia-like psychoses (LOP), the group often suffering of comorbid pathologies and experiencing substantial side-effects of drugs, we spred our approach to try “metabolic” medicines as adjunctives in LOP.ObjectivesTo reveal biochemical parameters of the blood cells which might be used for distinguishing subgroups of patients suffering with LOP for whom various adjunctive therapy (antioxidant, metabolic) would be advantageous.MethodsThe study included 59 patients 50-89 years old, with LOP (onset after 40 years), and 38 healthy peoples 51 – 84 years old. The activities of glutamate dehydrogenase (GDH), glutathione reductase (GR), and glutathione S-transferase (GST) were determined spectrophotometrically in erythrocytes and platelets. Scores by PANSS were evaluated twice: before and on the 28-th day of antipsychotic treatment.ResultsSamples from control group were used for determination of the control ranges for levels of studied enzymatic activities. Enzymatic activity levels were analyzed in three groups of patients: group Gr1 (n=16) treated without adjunctive therapy, and two other groups (Gr2 and Gr3) treated with adjunctive medicines: antioxidant 2-ethyl-6-methyl-3-hydroxypyridine succinate (Gr2, n=20), or “metabolic” medicines citicoline/cerebrolysin/cortexin/actovegin/gliatilin (Gr3, n=23).As compared with controls, activity of erythrocyte GR was decreased at baseline and after the treatment course in all patients’ groups (p<0.01); in Gr2 significant decreases in baseline platelet GDH and GST activities were observed (p=0.005). Different significant links between biochemical parameters and scores by clinical scales before treatment were observed: in Gr1, erythrocyte GST activity positively correlated with scores by PANSS-Neg (R=0.61, p=0.012), by PANSS-Psy (R=0.54, p=0.032), and by PANSS (R=0.62, p=0.010), in Gr2, erythrocyte GST activity positively correlated with scores by PANSS-Pos (R=0.53, p=0.016), by PANSS-Psy (R=0.52, p=0.015), and by PANSS (R=0.60, p=0.005), in Gr3, platelet GR activity positively correlated with PANSS-Pos (R=0.50, p=0.014).ConclusionsWe have confirmed the additional favor (decrease in side-effect severity) obtained by distinct patient groups when treated with adjunctive antioxidant or “metabolic” therapy. Moreover, correlations revealed in the patient subgroups between enzymatic activities and scores by psychometric scales enable revealing those biochemical markers measurement of which facilitate differentiating the patients for whom the adjunctive medicines to antipsychotic+antioxidant treatment can positively influence the treatment outcome.Disclosure of InterestNone Declared

Erythrocyte Glutathione S-Transferase Activity as a Sensitive Marker of Kidney Function Impairment in Children with IgA Vasculitis.

IgA vasculitis (IgAV) is the most common childhood vasculitis. The main cause of morbidity and mortality in children with IgAV is nephritis (IgAVN), but the risk of its development, severity, and chronicity remain unclear. Erythrocyte glutathione S-transferase (e-GST) activity has been previously detected as a sensitive marker of kidney function impairment in several diseases. We spectrophotometrically assessed and correlated e-GST activity between 55 IgAV patients without nephritis (IgAVwN), 42 IgAVN patients, and 52 healthy controls. At disease onset, e-GST activity was significantly higher in IgAVN patients (median (interquartile range)) (5.7 U/gHb (4.4-7.5)) than in IgAVwN patients (3.1 U/gHb (2.2-4.2); p < 0.001), and controls (3.1 U/gHb (1.9-4.2); p < 0.001). Therewithal, there were no differences between the IgAVwN patients and controls (p = 0.837). e-GST activity was also significantly higher in the IgAVN patients than in the IgAVwN patients after 3 months (5.0 U/gHb (4.2-6.2) vs. 3.3 U/gHb (2.3-4.1); p < 0.001) and 6 months (4.2 U/gHb (3.2-5.8) vs. 3.3 U/gHb (2.1-4.1); p < 0.001) since the disease onset. Consistent correlations between e-GST activity and serum creatinine, estimated glomerular filtration rate (eGFR), and proteinuria levels were not detected. In conclusion, increased e-GST activity can serve as a subtle indicator of kidney function impairment in children with IgAV.

Determination of erythrocyte Glutathione S-Transferase activity in individuals with gastric and colon cancer

Glutathione-S-Transferase (GST) in human cells has great importance in the detoxification mechanism of carcinogenic chemicals. Therefore, (GST) may be a useful tumor marker. This study examines whether GST activity in Gastric cancer (GC) and Colon Cancer (CC) is a helpful marker in diagnosing and monitoring the disease course. GST activity was investigated in patients with CC and GC and healthy individuals. Erythrocyte isolation was performed in 3 ml blood samples from volunteers aged 18-75 years. Hemoglobin amounts were determined from the standard graph drawn by monitoring the conversion of methemoglobin to cyanmethemoglobin in the presence of cyanide at 540 nm. Glutathione S-transferase activity was determined by measuring the amount of enzyme that catalyzes 1 µmol of S-(2,4-dinitrophenyl) glutathione formed per minute using 1-Chloro-2,4-Dinitrobenzene. The mean values of GST activities of patients with CC and GC, respectively; (1.28 ± 0.23 U/gHb; 1.20 ± 0.30 U/gHb), were significantly higher when compared to the mean values of healthy individuals with GST activity (0.59 ± 0.13 U/gHb) (p &lt; 0.05). The GST activity of patients with colon cancer, measured as (1.56 ± 0.13 U/gHb) after chemotherapy, was significantly higher than before (1.09 ± 0.12 U/gHb) (p &lt; 0.05). GST activity measured as (1.53± 0.24 U/gHb) after chemotherapy in gastric cancer patients was significantly higher when compared to the value measured before chemotherapy (0.97± 0.12 U/gHb) (p &lt; 0.05). Our results show that the change in GST activity in CC and GC can be used as a biomarker to monitor the disease course and response to chemotherapy.

Determination of erythrocyte Glutathione S-Transferase activity in individuals with gastric and colon cancer

Determination of erythrocyte Glutathione S-Transferase activity in individuals with gastric and colon cancer

Erythrocyte GST activity in type 2 diabetes with and without nephropathy

Diabetic nephropathy (DN) is the main cause of chronic kidney disease, and represents the most common and serious complication of diabetes. The occurrence and progression of DN are closely related to oxidative stress. Excessive reactive oxygen species (ROS) induced by hyperglycemia are involved in direct oxidation and damage of deoxyribonucleic acid (DNA), proteins, and lipids. Glutathione S-transferases have central roles in the cellular detoxification of a diverse group of exogenous and endogenous harmful compounds. The present study aims to clarify the possible role of erythrocyte glutathione S-transferase activity in type 2 diabetic patients with and without nephropathy. This study included 60 diabetic patients (20 diabetics with normoalbuminuria, 20 diabetics with microalbuminuria, 20 diabetics with macroalbuminuria) and 20 healthy volunteers as a control group. Glutathione S- transferase (GST), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) activities, and Reduced glutathione (GSH) level were significantly lower in diabetic patients with and without nephropathy as compared to control. Malondialdehyde (MDA) level was significantly higher in diabetic patients with and without nephropathy as compared to control. GST, SOD, GPx, CAT, GSH and MDA were positively correlated with estimated glomerular filtration rate and negatively correlated with albumin creatinine ratio. It was concluded that erythrocyte GST may be used as a biomarker to differentiate between different groups of nephropathy.

The activity of enzymes of glutathione metabolism in blood cells of patients with a high risk of manifestation of endogenous psychoses and patients with the first psychotic episode

To assess the activity of glutathione reductase (GR) and glutathione-S-transferase (GST) in blood cells of patients at clinical high-risk (HR) state for psychosis, in first-episode patients with schizophrenia and schizoaffective disorder (SD), and control group, and to seek correlations of these biochemical parameters with clinical assessments in patients. The study included male patients at HR (n=21, 16-25 years old), first-episode patients with schizophrenia (F20, n=14, 18-25 years old) and SD (F25, n=20, 16-25 years old), and 12 people of the control group (19-25 years old). Psychometric scales (SOPS, HDRS, and PANSS) and psychopathological methods were employed. GR and GST enzymatic activities were determined spectrophotometrically. The activities of platelet GR and GST in all groups of patients both before and after treatment were lower than in controls (p<0.01). The platelet GST activity was lower in patients at HR compared to patients with schizophrenia before treatment and lower than in patients with SD after treatment (p<0.05), it was higher in patients with schizophrenia than in patients with SD before treatment (p<0.05). Erythrocyte GST activity in patients with HR was lower than in patients with SD after treatment, and in the latter it exceeded that in patients with schizophrenia and controls (p<0.05). Complex and different patterns of changes in the activities of erythrocyte and platelet GR and GST in patients with schizophrenia spectrum disorders, occurring both before the first psychotic episode in the initial stage of disease, and in the first-episode patients, were detected. The activity of glutathione-converting enzymes in endogenous psychoses of the schizophrenic spectrum, including its early stages, can be used as a biomarker for predicting the development of psychosis, the course of disease, and as criteria for evaluation of therapeutic response to antipsychotic treatment.

Glutathione peroxidase and glutathione S-transferase in blood and liver from a hypoxia-tolerant fish under oxygen deprivation

Liver enzyme activities can be employed as biomarkers, but liver can only be obtained with death of the specimen. On the other hand, blood withdrawal is a non-lethal procedure. Accordingly, the hypothesis of this study is to verify if glutathione peroxidase (GPX) and glutathione S-transferase (GST) activities in blood parallel those in the liver of the hypoxia-tolerant fish, Piaractus mesopotamicus (pacu), submitted to hypoxia conditions. GPX was assayed with H2O2 in cytosols from both liver and erythrocytes and exhibited no significant variation, either in erythrocytes or in liver, when comparing pacus under normoxia with those under hypoxia (42 h). GST activity with chloro-dinitrobenzene (CDNB), an artificial substrate suitable for almost all GST isoenzymes, was compared to activity with 4-hydroxy-nonenal (4-HNE), a physiological endogenous substrate. GST activity with CDNB did not change in liver or in erythrocyte cytosols in pacus under hypoxia compared to those under normoxia. On the other hand, a significant decrease in erythrocyte activity with 4-HNE was observed after 42 h of hypoxia in both erythrocytes and liver, which may be a response to increased lipid oxidation in erythrocytes. Erythrocyte GST activity was 3-fold higher with 4-HNE than with CDNB, indicating that 4-HNE is a more appropriate substrate to determine GST activity in pacu erythrocytes.

The activity of erythrocyte and platelet glutathione reductase and glutathione-S-transferase in paranoid schizophrenia

A comparative evaluation of glutathione reductase (GR) and glutathione-S-transferase (GST) activities in erythrocytes and platelets of patients with schizophrenia. Fifty patients, 47 men and 3 women, aged 25-56 years (medium 34) with acute paranoid schizophrenia (F20.0 ICD-10) with hallucinatory-paranoid or paranoid syndrome were studied. The control group consisted of 48 healthy people, 45 men and 3 women, aged 21-59 years (medium 38). GR activity was determined by the oxidation of NADP-H in the reduction reaction of oxidized glutathione. GST activity was determined by the rate of chromogenic conjugate formation between glutathione and 1-chloro-2.4-dinitrobenzene. No differences in the erythrocyte GR and GST activities between the control group and patients with schizophrenia were found. The platelet activity of GR and GST was significantly lower in patients compared to the control group (Mann-Whitney U test, p<0.01). Spearman rank correlation analysis showed that the erythrocyte GST activity was significantly correlated with PANSSneg scores when measured at the beginning of the study, GST was higher in those patients who had less PANSSneg scores after treatment (R=-0.41, p<0.05). The activity of platelet GST in patients with schizophrenia was correlated with the severity of positive symptoms (PANSSpos score) at the beginning of the study before taking therapy (R=-0.31, p<0.05), i.e. the more prominent psychotic symptoms were expressed in patients with lower GST activity. Upon completion of therapy, this association disappeared. The activity of glutathione-dependent enzymes in the blood cells of schizophrenic patients determined before the beginning of antipsychotic pharmacotherapy may be important for objective assessment of this metabolic system status and the degree of its impairment in patients.

Effects of GSTM1/GSTT1 gene polymorphism and fruit & vegetable consumption on antioxidant biomarkers and cognitive function in the elderly: a community based cross-sectional study.

BackgroundIt was reported that Glutathione S-transferase (GST) gene polymorphism and fruit and vegetable (FV) intake were associated with body antioxidant capacity. The oxidative/anti-oxidative imbalance played an important role in the pathogenesis of AD. However, the association of GST genotype, dietary FV consumption with body antioxidant biomarkers and cognitive function in the elderly is not clear.ObjectiveThe aim of the present study was to determine the association of GST genotype, and dietary FV intake, with antioxidant biomarkers and cognitive function in the elderly.MethodsFood frequency questionnaire was used to collect data of dietary FV intakes in 504 community dwelling elderly aged from 55 to 75 years old. GSTM1 and GSTT1 genotypes were determined by using multiple-PCR method. Plasma and erythrocyte antioxidant biomarkers were measured. Cognitive function was measured by using Montreal Cognitive Assessment. Statistical analysis was applied for exploring the association of GST genotype and FV intake with antioxidant biomarkers level and cognitive function in the elderly.ResultsIndividual GSTM1 or GSTT1 gene deletion affects body antioxidant biomarkers levels, including erythrocyte GST activity, plasma total antioxidant capacity, and glutathione levels. GSTM1and/or GSTT1 gene deletion have no effects on cognitive function in the surveyed participants. The effect of GST genotype on antioxidant biomarkers are FV intake dependent. There is interaction of FV intake and GST genotype on cognitive function in the elderly.ConclusionGST genotype or daily FV consumption impact body antioxidant biomarkers, but not cognitive function in the elderly. There were combined effects of GST genotype and FV consumption on cognitive function in the elderly population. Large scale perspective population study is required to explore the association of GST genetic polymorphism, FV consumption and antioxidant biomarkers and cognitive function in the elderly.

The role of glutathioneS-transferase M1 and T1 gene polymorphisms and fruit and vegetable consumption in antioxidant parameters in healthy subjects

The correlation of glutathione S-transferase (GST) M1/T1 genetic polymorphisms with oxidative stress-related chronic diseases was proved recently. The aim of the present study was to investigate the association of GSTM1/T1 genetic polymorphisms with antioxidant biomarkers and consumption of fruits and vegetables (F&V) in healthy subjects. In this study, for conducting a 3 d dietary survey, 190 healthy adults were recruited. After DNA extraction, a multiple PCR method was used for GSTM1/T1 genotyping. A spectrophotometer method was applied for the determination of plasma total antioxidant capacity (T-AOC), vitamin C level and erythrocyte GST enzyme activity. A general linear model was used to compare the mean values of antioxidant parameters for different GSTM1/T1 genotypes and consumption of F&V. Polymorphisms of GSTM1/T1 had no effects on plasma T-AOC and vitamin C levels. Deletion of the GSTM1 gene decreased the erythrocyte GST activity. There was correlation between plasma T-AOC and consumption of F&V in the GSTM1⁻ or GSTT1⁺ subjects. A similar pattern was evident for erythrocyte GST activity in the GSTM1⁻ subjects. No association was found among consumption of F&V and GSTM1/T1 genotypes and plasma vitamin C level. Different consumption of F&V had no impact on plasma T-AOC and vitamin C levels in the GSTM1⁻/GSTT1⁺ or GSTM1⁻/GSTT1⁻ subjects. The erythrocyte GST activity was more sensitive to consumption of F&V in the individuals with the GSTM1⁻/GSTT1⁺ genotype. Association was found among GSTM1/T1 genotypes, antioxidant parameters and consumption of F&V. Large-scale and multiple ethnic studies are needed to further evaluate the relationship.

Glutathione S-Transferase Activity of Human Erythrocytes Incubated in Aqueous Solutions of Five Antimalarial Drugs

Levels of human erythrocyte glutathione S-transferase (GST) activity were ascertained in the presence of separate increasing concentrations (0.2, 0.4, 0.6, and 0.8 mg% w/v) of five antimalarial drugs {Pyrimethamine/Sulphadoxine (PS), Halofantrine-HCl (H-HCl), Quinine, Artemether/umefantrine (AL) and Chloroquine Phosphate (CP)} in vitro. Determination of erythrocyte GST activity was carried out by spectrotrophotometric method with the standard substrate (1-chloro-2, 4-dinitrobenzene) and co-substrate (reduced gluthathione) at maximum absorbance (λmax) = 340 nm. Human erythrocyte GST activity ranged between 3.27 ± 0.13 and 3.40 ± 0.05 iu/gHb. The addition of increasing concentrations of four antimalarial drugs to assay mixture engendered decreased levels of GST activity in a concentration dependent manner, which was in the order: CP > AL > Quinine > PS. Specifically, 0.8 mg% CP exhibited the highest capacity to cause decreased GST activity from values of 3.41 ± 0.06 to 2.18 ± 0.09 iu/gHb, representing 33.7% relative inhibition of GST activity. In contrast, concentrations of H-HCl between 0.2 and 0.6 mg% caused elevation of GST activity above the values of the control samples. However, the increased levels of GST activity was not significantly different (p > 0.05) compared with the control samples. The five antimalarial drugs exhibited variable capacities to alter human erythrocyte GST activity, which suggest the capability of these drugs to perturb the redox status of human erythrocytes.

Assessment of the Effect of Aluminium, Lead and Cadmium on Human Erythrocyte Glutathione S‐Transferase Activity In‐vitro

The effects of aluminium, lead and cadmium on the activity of human erythrocyte glutathione S-transferase (GST) have been investigated in-vitro. Erythrocytes from healthy volunteers were incubated with aluminium, lead and cadmium at various amounts (nM-mM). After erythrocyte fragments were removed by centrifugation, GST activity was measured. Aluminium exhibited a maximum inhibition of 38·13% at 45 mM. Lead showed a maximum inhibition of 85·02% at 50 mM, whereas with cadmium a maximum inhibition of 72·68% was detected at 80 mM. Our results show that very high concentrations of these metals can inhibit the activity of human erythrocyte GST. However, aluminium, lead and cadmium at blood levels which are toxic do not inhibit erythrocyte GST activity in-vitro.

Comparative Study of Glutathione S-Transferase Activity of Three Human Erythrocyte Genotypes Infected With &lt;i&gt;Plasmodium falciparum&lt;/i&gt;.

Investigation to ascertain the levels of glutathione S-transferase (GST) activity of three human erythrocyte genotypes (HbAA, HbAS and HbSS) obtained from apparently healthy and clinically confirmedmalarious subjects/volunteers was carried out. The incubation of human erythrocytes with 1-chloro-2,4- dinitrobenzene (CDNB) resulted in almost quantitative conjugation of glutathione (GSH) to form S-(2,4-dinitrophenyl) glutathione. The reaction formed the basis for the spectrophotometric determination of GST activity. The levels of GST activity of the red cell genotypes was in the order of bAA0.05) affect erythrocyte GST activity of non-malarious subjects/volunteers. The study suggests that GST activity evaluation might be a reliable biochemical marker and possess promising rational for diagnostic potential in malaria

Short Communication: Erythrocyte Glutathione S-transferase Activity of Non-Malarious Male Human Volunteers Administered with Five Antimalarial Drugs

Investigation to ascertain the potencies of five antimalarial drugs (Fansidar, Halfan, Quinine, Coartem and Chloroquine phosphate) to alter/distort non-parasitized human erythrocyte (HbAA genotype) glutathione S-transferase (GST) activity was carried out. Apparently healthy and clinically confirmed non-malarious male human volunteers enrolled for this study. The incubation of human erythrocytes with 1-chloro-2, 4-dinitrobenzene (CDNB) resulted in almost quantitative conjugation of glutathione (GSH) to form S-(2, 4-dinitrophenyl) glutathione. The reaction formed the basis for the spectrophotometric determination of GST activity. Determination of GST activity was carried out before and after the five (5) drug treatments.The control values ranged between 3.27+0.13 iu/gHb and 3.40+0.05 iu/gHb. Generally, the erythrocyte GST activity was time dependent of the five antimalarial drugs showing biphase profile. The first phase showed decrease levels of relative GST activity within approximate time range: (0 results of these findings suggested the capability of these drugs to bind to the human erythrocyte GST, accompanied with raised oxidant stress of the erythrocytes. Keywords: Glutathione S-transferase (GST) activity, erythrocytes, antimalarial drugs, humans, 1-chloro-2, 4- dinitrobenzene (CDNB).

Erythrocyte glutathione S-Transferase activity in human administered with five antimalarial drugs

In vivo investigation to ascertain the capacities of five antimalarials drugs (Fansidar, Halfan, quinine, Coartem and chloroquine phosphate) to alter/distort non-parasitized human erythrocyte (HbAA genotype) glutathione S-transferase (GST) activity was carried out. Apparent healthy and clinically confirmed non-malarious male volunteers enrolled for this study. The incubation of human erythrocytes with 1-chloro-2,4-dinitrobenzene (CDNB) resulted in almost quantitative conjugation of glutathione (GSH) to form S-(2,4-dinitrophenyl) glutathione. The reaction formed the basis for the spectrophotometric determination of GST activity. Determination of GST activity was carried out before(control; t=0 hour) and after (tests; i.e. at t=3, 6 and 18 hours) the five (5) antimalarial drugs were administered to the human volunteers. The control/reference values ranged between 3.27±0.13 and 3.40±0.05 )iu/gHb. Generally, the pattern of in vivo erythrocyte GST activity with time in the presence of the five antimalarial drugs showed a two-phaseprofile. The first stage showed decreasing levels of relative GST activity within approximate time range: (6

Glutathione S-transferase activity of erythrocyte genotypes HbAA, HbAS and HbSS in male volunteers administered with fansidar and quinine

In vivo investigations were carried out to ascertain the comparative levels of erythrocyte GST activity between non-malarious and malarious male subjects of HbAA, HbAS and HbSS erythrocyte genotypes, administered with fansidar and quinine. The incubation of human erythrocytes with 1-chloro-2,4-dinitrobenzene (CDNB) resulted in almost quantitative conjugation of glutathione (GSH) to form S-(2,4-dinitrophenyl) glutathione. Determination of GST activity was carried out at 0, 3, 6 and 18 h, after two antimalarial drugs (Fansidar and quinine) were adminis-tered to the volunteers. The control values of non-malarious and malarious individuals ranged between (3.27 to 12.50 iu/gHb) and (2.75 to 12.21 -iu/gHb) respectively. Erythrocyte GST activity was significantly (p < 0.05) lower in P. falciparum infected red cells compared to normal ones, except parasitized male HbSS erythrocytes. Generally, the pattern of in vivo erythrocyte GST activity in the presence of the 2 antimalarial drugs showed 2 phase profile. The first stage showed decreasing levels of relative GST activity within approximate time range of 6 h after the drugs were administered to the volunteers. The second phase showed recovery of erythrocyte GST activity (6 - 18 h approx.) from the inhibitory effects of the drugs. Key words: Glutathione S-transferase (GST) activity, erythrocytes, fansidar, quinine, 1-chloro-2, 4-dinitrobenzene (CDNB).

Erythrocyte antioxidant defense response against cigarette smoking in humans—the glutathione S‐transferase vulnerability

Cigarette smoking leads to uptake of a multitude of reactive chemicals including many electrophiles and may also give rise to oxidative stress. Human red blood cells are important targets for electrophilic and oxidant foreign compounds. We investigated the oxidative stress in erythrocytes upon cigarette smoking, and the response of antioxidant defense system against it. With this aim, simultaneous determination of erythrocyte superoxide dismutase (SOD), selenium dependent glutathione peroxidase (Se-GPx), catalase (CAT), glutathione S-transferase (GST) activities and plasma levels of thiobarbituric acid reactive substances (TBARS), and the degree of erythrocyte membrane lipid peroxidation (EMLP) were carried out in blood samples of smokers and their controls. Plasma TBARS levels and EMLP in smokers were significantly higher than the control levels (p < 0.01 and p < 0.005, respectively). SOD activity was diminished in smokers compared to nonsmoker controls (p < 0.005). Erythrocyte Se-GPx activity was also found significantly diminished in smokers (p < 0.005), while plasma Se-GPx activity was not changed. We observed that erythrocyte CAT activity was not different in smokers compared to nonsmoker controls. We found that the erythrocyte GST activity is significantly lower in young adult smokers (3.03 +/- 0.18 U/mg protein; mean +/- SEM; n = 46) than in nonsmoking contemporaries (3.98 +/- 0.26 U/mg protein; mean +/- SEM; n = 41). Together with previously reported data, it can be concluded that the decrease in GST activity leads to extra GST synthesis during erythrocyte proliferation. The same data were also analyzed for the sex differences. The statistically significant differences remained the same between nonsmoker and smoker females. Only EMLP degree and SOD activity were significantly different between nonsmoker and smoker males; however, when compared the parameters between male and female nonsmokers, GST activity was found to be significantly higher in females than that of males.

The effect of prostate cancer and antiandrogenic therapy on lipid peroxidation and antioxidant systems.

In living organism, excessive free radicals or oxidative damage which occur as a result of deficient antioxidant defensive mechanisms by the effect of endogenous and exogenous factors, influences especially developmental steps of chemically induced cancers. In our study, plasma malondialdehyde level (MDA) as an indicator of lipid peroxidation, erythrocyte glutathione (GSH) level as an indicator of antioxidant state, glutathione reductase (GSH-Red), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) as an antioxidant enzymes and plasma vitamin E level were detected in patients with prostate cancer (21 males; age, 69.4 +/- 4.8 years) before and after three months of antiandrogenic therapy with goserelin acetate as luteinizing hormone releasing hormone (LHRH) analogue. Healthy people evaluated as a control group (20 males; age, 63.7 +/- 3.9). Erythrocyte GSH levels, the activities of GSH-Red and GSH-Px and plasma vitamin E levels were found significantly low in patients with prostate cancer when compared with the healthy subjects (p < 0.01, p < 0.05, p < or = 0.001 and p < or = 0.001 respectively). Plasma MDA level and erythrocyte GST activity of patient group were significantly higher than the levels of control group (p < or = 0.001 and p < or = 0.001 respectively). After antiandrogenic therapy erythrocyte GSH level, GSH-Red, GSH-Px activity and plasma vitamin E level were found unchanged. Significant decrease in plasma MDA level and significant increase in erythrocyte GST activity were detected in patient group (p < 0.05 and p < or = 0.01 respectively). The study has revealed the shift in the oxidant-antioxidant balance towards oxidative state in patients with metastatic prostate cancer. Our results showed that antiandrogenic therapy increased in GST activity, decreased in lipid peroxidation.

Circulating biomarkers of oxidative stress in complicated pregnancies.

Increased lipid peroxidation (LPO) and reduced antioxidant activity may contribute to the development of complications in pregnancy. The present study discusses the possibility of LPO and antioxidant activity in both maternal and umbilical cord blood as an indicator of oxygen radical activity. For this aim, pregnancies with hypertension and pre-eclampsia, diabetes mellitus (insulin dependent diabetes mellitus and gestational diabetes mellitus), oligohydramnios and abruptio placentae, as well as a healthy control group, were subjected in the present study. Simultaneous determination of glutathione S-transferase (GST), selenium dependent glutathione peroxidase (Se-GPx), catalase (CAT) activities and thiobarbituric acid reactive-substances (TBARs) levels were carried out in maternal erythrocyte and plasma in the antenatal period (in the third trimester) and immediately after the delivery. The same oxidative stress-related parameters were determined in umbilical cord blood as well. Erythrocyte GST activity was significantly increased in insulin-dependent diabetic pregnancy (IDDP) when compared to the control (P<0.05). Erythrocyte Se-GPx activity was found to be significantly increased in hypertensive preeclamptic pregnancy (HPP) (P<0.05) and in IDDP (P<0.05). Alterations in enzyme activities were accompanied by a simultaneous significant increase in the levels of TBARs in plasma samples of HPP (P<0.05), and IDDP (P<0.05). Enzyme activities were found to be significantly lower in cord blood samples than the maternal values, except GST. This enzyme represents about two- to threefold higher activity than those of the maternal activity in uncomplicated and complicated groups. Cord blood erythrocyte and plasma Se-GPx and CAT activities were decreased significantly in the HPP group when compared to the maternal value (P<0.05). Cord blood erythrocyte CAT activity was significantly decreased in the HPP group compared to the control (P<0.05). Cord blood TBARs levels were significantly lower than the before deliveries maternal value in the HPP group (P<0.05). No difference was detected between umbilical cord blood and maternal blood TBARs levels after delivery. The results of the present study suggest that oxidative stress and subsequent lipid peroxidation accompany the complications of hypertension, preeclampsia and diabetes mellitus in pregnancy. Maternal erythrocyte GST activity seems to be a sensitive indicator of oxidative stress in IDDP before delivery. The same enzyme can be used in cord blood as a biomarker of oxidative stress upon a sudden increase in oxygenation during delivery. These multiparameter biomarkers can also be used in monitoring the efficiency of antioxidant supplementation in complicated pregnant women, as has recently been suggested for diabetic and preeclamptic pregnancies.

Cadmium-Induced Lipid Peroxidation and the Antioxidant System in Rat Erythrocytes : the Role of Antioxidants

Cadmium (Cd)-induced oxidative damage in erythrocytes causes loss of membrane function by enhancing lipid peroxidation (LPO) and altering the erythrocyte antioxidant system. Vitamin E and/or selenium (Se) was administered to rats, prior to Cd intoxication, in order to prepare the animals to withstand oxidative assault. The treatment with Cd increased LPO in erythrocytes while animals pretreated with vitamin E and/or Se prior to Cd treatment showed decreased LPO as compared with animals given Cd alone. The erythrocyte SOD and CAT activities decreased significantly with Cd treatment. The pretreatment with vitamin E and/or Se prior to Cd administration partially reversed such changes. The erythrocytes showed a marked depletion in glutathione (GSH) content with Cd treatment. The antioxidant treatments before Cd administration helped to maintain the erythrocyte GSH content. The erythrocyte glutathione reductase (GSH-R) activity increased markedly when treatments with vitamin E and Se were applied. The GSH-R activity was not observed to decrease in animals treated with antioxidant prior to Cd intoxication, which may mean that the replenishment of erythrocyte GSH content is via GSH-R. The glutathione-S-transferase (GST) activity increased significantly with Cd intoxication; however, treatment with antioxidants prior to Cd treatment decreased erythrocyte GST activity. The results show that Cd-induced LPO decreased the antioxidant capability of the erythrocytes, causing erythrocyte membrane damage.