Specific Activity Of Glutathione Peroxidase Research Articles

Experience of measuring glutathione peroxidase activity in surgically induced endometrial-like lesions in rats

BACKGROUND: Endometriosis is known to be linked with altered activities of antioxidant enzymes and with their gene polymorphisms. Progestins are known to induce glutathione peroxidase activity in the endometrium and promote reduction of endometrial lesions. It could be useful to estimate the correlation between the activity of glutathione peroxidase within endometrial lesions and their degree of reduction.
 AIM: The present study was aimed at estimating glutathione peroxidase activity in surgically induced endometrial-like lesions of different degree of reduction in rat model of endometriosis.
 MATERIALS AND METHODS: The method for determining glutathione peroxidase activity using hydrogen peroxide as a substrate and 5,5-dithiobis(2-nitrobenzoic acid) for estimation of residual reduced glutathione was applied for quantitative analysis of the enzyme activity in endometriotic foci, surgically induced in female Wistar rats. An assay of glutathione peroxidase activity in tissue homogenates was performed at 37C in a reaction medium containing Tris-HCl buffer supplemented with tetrasodium ethylenediaminetetraacetate and sodium azide (pH 8.5) in the presence of 0.55 mM reduced glutathione and 0.192 mM hydrogen peroxide. Before adding trichloroacetic acid, 40-second incubation was used. The correlation between the specific activity of the enzyme and protein amount in endometriotic foci was estimated.
 RESULTS: In a rat model of endometriosis, there was a high, well-determined glutathione peroxidase activity in endometriotic foci. For the same endometriotic tissue sample, the enzymatic activity was proportional to the amount of protein in the reaction mixture. The range of specific glutathione peroxidase activity was 2.436.45 micromoles of consumed glutathione per minute per milligram of protein (n = 7). In most reduced endometriotic foci (with the minimum amount of endometriotic tissue), the highest specific activity of glutathione peroxidase was found (the Spearmans rho of 0.93 with p = 0.0067).
 CONCLUSIONS: The method for determining glutathione peroxidase activity using hydrogen peroxide and 5,5-dithiobis(2-nitrobenzoic acid) is convenient for working with the endometriotic tissue in a rat model of endometriosis. We can accept, with p 0.01, that weight of endometriotic foci is negatively linked with specific glutathione peroxidase activity within their tissue. The results are analogous to the previously obtained data on catalase activity and suggest the involvement of both antioxidant enzymes in reduction of endometrial lesions.

Effect of an Intracerebroventricular Injection of Aggregated Beta-amyloid (1–42) on Daily Rhythms of Oxidative Stress Parameters in the Prefrontal Cortex

Accumulation of amyloid peptides in the brain plays a key role in the pathogenesis of Alzheimer's disease (AD). Aggregated beta-amyloid (Aβ) peptide increases intracellular reactive oxygen species associated to a deficient antioxidant defense system. Prefrontal cortex plays a key role in memory and learning and is especially susceptible to oxidative stress. The objective of this work was to investigate the effects of an intracerebroventricular (i.c.v.) injection of Aβ (1–42) on 24 h patterns of oxidative stress parameters and antioxidant defenses in the rat prefrontal cortex. Four-month-old male Holtzman rats were divided into two groups defined as: control (CO) and Aβ-injected (Aβ). Rats were maintained under12 h-light:12 h-dark conditions and received water and food ad libitum. Tissues samples were isolated every 6 h during a 24 h period. Interestingly, we found that an i.c.v. injection of Aβ(1–42) increased lipid peroxidation, reduced total antioxidant capacity level, phase-shifted the daily peak of reduced glutathione, and had a differential effect on the oscillating catalase and glutathione peroxidase specific activity. Thus, elevated levels of Aβ aggregates-a pathogenic hallmark of AD, caused altered temporal patterns of the cellular redox state in prefrontal cortex rat. These findings might contribute, at least in part, to the understanding of the molecular and biochemical basis of redox changes caused by circadian rhythms alterations observed in AD patients.

Impact of thermal stress exposure on seminal quality, antioxidant defence system, TNF-α and TIMP-3 in Ossimi ram.

Heat stress (HS) occupies huge importance nowadays as it leads to severe economic losses especially in livestock. Preserving sheep against HS is one of the governmental scopes where it represents huge percentage of global ruminant. The present research was conducted to study semen quality, some stress and inflammatory markers in Ossimi rams under both hot and mild climatic conditions. The current study was conducted on selected 46 ram samples divided into two groups during summer and winter. Semen analysis, testosterone (TES), cortisol (COR) and blood glucose (BG) levels, and lipid and protein profiles were done. Concentrations of tumour necrosis factor alpha (TNF-α), tissue inhibitor of metalloproteinase-3 (TIMP-3), nitric oxide (NO), malondialdehyde (MDA) and reduced glutathione (GSH) and specific activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were assessed. The results in summer compared to winter revealed significant elevation of total defects and number of dead sperms; however, there was reduction in sperm total motility and concentration and external epididymal tail duct diameter. Histological study of epididymal tail lumen exhibited azoospermia. Further, TES, TIMP-3 and GSH levels were decreased and COR, TNF-α, NO and MDA were raised. Specific activities of GPx and SOD were also declined. Additionally, there was a significant increase in concentrations of BG and lipid profiles except high-density lipoprotein. Our data concluded that there were new insights into TNF-α and TIMP-3 as biomarkers can be used in diagnosis of sheep suffering from HS, but further studies are recommended to do in future work about such aspect.

Effect of a high amino acid diet on antioxidant barrier parameters of rat skin. Part 2

<b>Purpose:</b> The imbalance between the formation of reactive oxygen species and antioxidant capacity of the body is known as oxidative stress. Exposition of the skin to free radicals, the origin of the internal and external causes activation of multiple mechanisms to eliminate them and prevent in this way the development of oxidative stress. The aim of this experiment was examining what changes are taking place in the antioxidant barrier of unwounded healthy skin of rats, who are on a high amino acids diet for 7 and 14 days at administered doses of 0.3 and 0.5 g/kg body weight. <br/><b>Materials and Methods:</b> The study was performed on male Wistar rats divided into 5 groups: 1. control (standard feed), 2. high amino acid diet (WPC-80 80% whey protein) administered for 7 days at a dose of 0.3g/kg of body weight, 3. WPC-80 for 7 days at a dose of 0.5g/kg of body weight, 4. WPC-80 for 14 days at a dose of 0.3g/kg of body weight, 5. WPC-80 for 14 days at a dose of 0.5g/kg of body weight. The concentration of superoxide dismutase 2 and 3, the concentration of catalase specific activity of glutathione peroxidase, the concentration of glutathione and total protein content were determined. <br/><b>Results:</b> The supplementation of the standard diet by the preparation of WPC-80 administered in a dose 0.5 g/kg body weight for 14 days containing methionine and cysteine (essential amino acids involved in the formation of glutathione), significantly increases the concentration of reduced glutathione. <br/><b>Conclusions:</b> Enrichment of a standard diet with WPC-80 caused by the significant increases of non-enzymatic antioxidant.

The Effect of Exercising on Oxidative Stress Status and Pain in a Valproic-acid Induced Model of Autism Possible relevance of oxytocin

In this report we will describe the effect of exercising (6 days, each day 3 separate training phases of 5 minutes each, on an adapted treadmill at 1.0 m/s) on oxidative stress status from the temporal lobe (expressed through 3 main parameters: superoxide dismutase (SOD), glutathione peroxidase (GPX) and malondialdehyde (MDA), as a marker of lipid peroxidation) and pain (as determined through 2 specific behavioural tasks such as hot plate test for the supraspinal acute thermal pain and the intra abdominal Zymosan administration for eliciting a local inflammatory reaction following responses to inflammatory visceral pain) in a rat valproic-acid induced perinatal model of autism, also trying to emphasize a possible implication of oxytocin in this complex pathological picture. We demonstrated here an increased oxidative stress status, as a result of treadmill exercising, in a VPA rat induced model of autism, as demonstrated mainly by a significant decrease in the specific activity of SOD (for the exercised VPA female rats), as well as a significant decrease of GPX specific activity in the male VPA exercised rats, when compared to non-exercised VPA groups, as well as the fact that the aforementioned series of exercises did not resulted in any changes of the pain perception of this rat models of autism, as studied in 2 pain-related behavioural tasks, independent to the gender of the rats with VPA model of autism.

The effect of intermittent hypobaric-hypoxia treatments on renal glutathione peroxidase activity of rats

Many people living at high altitudes experiencing a condition called intermittent hypobaric hypoxia (IHH). Some people even create IHH condition as an exercise for pilots, athletes, and mountaineers. In this experiment, we aimed to determine whether the protective effect of IHH is mediated through glutathione peroxidase (GPX) enzyme. The experiment’s sample is two-month-old healthy Sprague-Dawley rat kidneys weighing 200–250 g. Intermittent hypobaric hypoxia treatment is done using a Hypobaric Chamber type I that can mimic air pressure at certain altitudes: 35,000 (one minute), 30,000 (three minutes), 25,000 (five minutes), and 18,000 (30 minutes) feet. The rats were divided into five treatment groups, including a control group, hypobaric-hypoxia group, and intermittent hypobaric-hypoxia 1x, 2x, and 3x groups with each group consisting of three rats. The specific activity of GPX was measured using RANDOX and RANSEL methods. The statistical analysis of one way-ANOVA did not show significant differences between the groups (p > 0.05), although specific activities of the renal GPX of rats exposed to hypobaric-hypoxia were higher than the control group. This may be caused by the other antioxidants’ activities. In conclusion, the IHH treatment did not affect GPX activity in the rat kidneys.

Anti-acetylcholinesterase and Antioxidant Activities of Inhaled Juniper Oil on Amyloid Beta (1-42)-Induced Oxidative Stress in the Rat Hippocampus.

Juniper volatile oil is extracted from Juniperus communis L., of the Cupressaceae family, also known as common juniper. Also, in aromatherapy the juniper volatile oil is used against anxiety, nervous tension and stress-related conditions. In the present study, we identified the effects of the juniper volatile oil on amyloid beta (1-42)-induced oxidative stress in the rat hippocampus. Rats received a single intracerebroventricular injection of amyloid beta (1-42) (400 pmol/rat) and then were exposed to juniper volatile oil (200 μl, either 1 or 3 %) for controlled 60 min period, daily, for 21 continuous days. Also, the antioxidant activity in the hippocampus was assessed using superoxide dismutase, glutathione peroxidase and catalase specific activities, the total content of the reduced glutathione, protein carbonyl and malondialdehyde levels. Additionally, the acetylcholinesterase activity in the hippocampus was assessed. The amyloid beta (1-42)-treated rats exhibited the following: increase of the acetylcholinesterase, superoxide dismutase and catalase specific activities, decrease of glutathione peroxidase specific activity and the total content of the reduced glutathione along with an elevation of malondialdehyde and protein carbonyl levels. Inhalation of the juniper volatile oil significantly decreases the acetylcholinesterase activity and exhibited antioxidant potential. These findings suggest that the juniper volatile oil may be a potential candidate for the development of therapeutic agents to manage oxidative stress associated with Alzheimer's disease through decreasing the activity of acetylcholinesterase and anti-oxidative mechanism.

Increased oxidative stress status in rat serum after five minutes treadmill exercise

Abstract Although it is accepted that an important correlation exists between the physical exercise and the oxidative stress status, the data regarding the levels of the main oxidative stress markers after physical training have been difficult to interpret and a subject of many controversies. There are also very few studies regarding the effects of short-time exercise on the oxidative stress status modifications. Thus, in the present report we were interested in studying the modifications of some oxidative stress markers (two antioxidant enzymes-superoxide dismutase and glutathione peroxidase, a lipid peroxidation parameter — malondyaldehide, the total antioxidant status and protein carbonyl levels), from the serum of rats that were subject to one bout of five minutes exercise on a treadmill, when compared to a control sedentary group. In this way, we observed a decrease of superoxide dismutase specific activity in the rats which performed the exercises. Still, no modifications of glutathione peroxidase specific activity were found between groups. In addition, increased levels of malondyaldehide and protein carbonyls were observed in the rats subjected to exercises. In conclusion, our data provides new evidence regarding the increase of the oxidative stress status, as a result of a 5-minutes bout of treadmill exercising in rats, expressed through a decrease in the SOD specific activity and the total antioxidant status and also an increase of the lipid peroxidation and protein oxidation processes.

Regulation of the unbalanced redox state in a Schizosaccharomyces pombe tert-butyl hydroperoxide-resistant mutant.

The one-gene mutation in the tert-butyl hydroperoxide-resistant mutant hyd1-190 of the fission yeast Schizosaccharomyces pombe led to a 4-fold increase in resistance to t-BuOOH and decreased specific concentrations of superoxide and total thiols in comparison with the parental strain hyd+. It suggested an unbalanced redox state of the cells, which induced continuously increased specific activities of glutathione peroxidase, glutathione reductase and glutathione S-transferase and decreased activities of the antioxidant enzymes superoxide dismutases and glucose-6-phosphate dehydrogenase to regulate the redox balance of the mutation-induced permanent, low-level but tolerable internal stress. These results may contribute to the understanding of internal, oxidative stress-related human diseases.

Saxitoxins induce cytotoxicity, genotoxicity and oxidative stress in teleost neurons in vitro

The aim of this study was establish a protocol for isolation and primary culture of neurons from tropical freshwater fish species Hoplias malabaricus for assessment of the effects of neurotoxic substances as saxitoxins (STXs). Cells from brain of H. malabaricus were treated with different concentrations of trypsin, dispase and papain for tissue dissociation. Cells type was separated by cellular gradient and basic fibroblast growth factor (bFGF) supplement nutrition media were added. The dissociated cells were plated with medium and different STXs concentrations and the toxic cellular effects such as oxidative stress, neurotoxicity, and genotoxicity and apoptosis process were evaluated. Cultures treated with bFGF showed the greatest adherence, survival and cellular development. STXs increased specific activity of glutathione peroxidase and lipoperoxidation levels, were cytotoxic and genotoxic indicated by the comet assay. Although the STXs effects due the blockage of sodium channels is reported to be reversible, the time exposure and concentration of STXs suggested cellular injuries which can lead to neuropathology. The establishment of primary neuronal culture protocol enables new applications for neurotoxicological assessments.

Methanolic Extract of Piper nigrum Fruits Improves Memory Impairment by Decreasing Brain Oxidative Stress in Amyloid Beta(1–42) Rat Model of Alzheimer’s Disease

The present study analyzed the possible memory-enhancing and antioxidant proprieties of the methanolic extract of Piper nigrum L. fruits (50 and 100 mg/kg, orally, for 21 days) in amyloid beta(1-42) rat model of Alzheimer's disease. The memory-enhancing effects of the plant extract were studied by means of in vivo (Y-maze and radial arm-maze tasks) approaches. Also, the antioxidant activity in the hippocampus was assessed using superoxide dismutase-, catalase-, glutathione peroxidase-specific activities and the total content of reduced glutathione, malondialdehyde, and protein carbonyl levels. The amyloid beta(1-42)-treated rats exhibited the following: decrease of spontaneous alternations percentage within Y-maze task and increase of working memory and reference memory errors within radial arm-maze task. Administration of the plant extract significantly improved memory performance and exhibited antioxidant potential. Our results suggest that the plant extract ameliorates amyloid beta(1-42)-induced spatial memory impairment by attenuation of the oxidative stress in the rat hippocampus.

Enzymes of the glutathione–ascorbate cycle in leaves and roots of rhizobia-inoculated faba bean plants (Vicia faba L.) under salinity stress

Grain legumes such as the faba bean (Vicia faba L.) used for human as well as animal nutrition, are of great importance especially in countries under Mediterranean climate like Morocco, which is mainly characterized by semi-arid and arid climates and by saline soils. The objective of the present study was to evaluate the effects of salt stress on growth, nodulation and the enzymes of the glutathione–ascorbate cycle of faba bean plants (Moroccan cultivar “Aguadulce”). The experiments were carried out under greenhouse conditions, where faba bean plants were grown under control (nutrient solution) or salt stress conditions (nutrient solution containing 75 mM or 150 mM of NaCl). The activity of enzymes of the glutathione–ascorbate cycle was studied in leaves and roots of faba bean plants inoculated by rhizobia RhOF4 or RhOF6, isolated from nodules of faba bean cultures in the region of Marrakech. The growth of faba bean plants decreased with increasing salt concentrations. Total weight and length of shoots significantly decreased under NaCl stress (p < 0.05), especially at 150 mM. Also the nodulation of the roots was strongly decreased under salinity stress, with reductions of 91.35% and of 88.67% in the total nodule number of plants exposed to 150 mM of NaCl and inoculated by RhOF4 and by RhOF6 respectively. NaCl effects on the glutathione–ascorbate cycle were more pronounced in roots inoculated by RhOF6. Stress responding glutathione S-transferase (GST) activity was generally increased in roots inoculated by RhOF6 and submitted to salt stress. On the contrary, specific activities of glutathione peroxidase (GPOX), superoxide dismutase (SOD), ascorbate peroxidase (APOX) and monodehydroascorbate reductase (MDHAR) were reduced in roots of faba bean plants inoculated by RhOF6 exposed to saline treatment as compared to the controls. Our results show the importance of several enzymes of the ascorbate–glutathione cycle and the reduced glutathione (GSH) during some faba bean–rhizobia symbiotic combinations, in root defence and adaptation against salt stress conditions.

Cognitive-enhancing and antioxidant activities of inhaled coriander volatile oil in amyloid β(1–42) rat model of Alzheimer's disease

Coriandrum sativum L., commonly known as coriander and belonging to the Apiaceae family is cultivated throughout the world for its nutritional value. In traditional medicine, coriander is recommended for the relief of pain, anxiety, flatulence, loss of appetite and convulsions. In the present study, the effects of inhaled coriander volatile oil (1% and 3%, daily, for 21days) extracted from C. sativum var. microcarpum on spatial memory performance were assessed in an Aβ(1–42) rat model of Alzheimer's disease. The Aβ(1–42)-treated rats exhibited the following: decrease of spontaneous alternations percentage within Y-maze task and increase of working memory errors, reference memory errors and time taken to consume all five baits within radial arm maze task. Exposure to coriander volatile oil significantly improved these parameters, suggesting positive effects on spatial memory formation. Assessments of oxidative stress markers in the hippocampal tissue of Aβ(1–42)-treated rats showed a significant increase of superoxide dismutase (SOD), lactate dehydrogenase (LDH) and a decrease of glutathione peroxidase (GPX) specific activities along with an elevation of malondialdehyde (MDA) level. Coriander volatile oil significantly decreased SOD and LDH specific activities, increased GPX specific activity and attenuated the increased MDA level. Also, DNA cleavage patterns were absent in the coriander rats, thus suggesting antiapoptotic activity of the volatile oil. Therefore, our results suggest that exposure to coriander volatile oil ameliorates Aβ(1–42)-induced spatial memory impairment by attenuation of the oxidative stress in the rat hippocampus.

A study of the levels of glutathione peroxidase in patients with spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis (SBP) is a major complication of liver cirrhosis, which is associated with increased mortality. While recent studies have demonstrated the involvement of reactive oxygen species in the pathogenesis of liver cirrhosis, the role of oxidative stress in the development of SBP has not yet been completely established. The present study aims to evaluate the role of oxidative stress in the pathogenesis of this complication and also the relevance of the specific treatment on these aspects. We present here some of our preliminary results regarding the specific activity of glutathione peroxidase (GPX), a very important antioxidant enzyme, from both serum and ascitic fluid of patients with decompensated cirrhosis and SBP, patients diagnosed with decompensated liver cirrhosis with ascites and patients with compensated liver cirrhosis. Our results demonstrate the presence of an increased oxidative stress in patients with decompensated cirrhosis and SBP compared with those without SBS and those with compensated liver cirrhosis, as demonstrated through the significant decrease of the specific activity of GPX. The measurement of these oxidative stress parameters may have an important role in the diagnosis and follow-up of this important liver pathology and the auxiliary treatment.

P03-296 - Oxidative stress markers in patients treated with typical and atypical antipsychotics

IntroductionStudies performed in schizophrenia patients have generally suggested the presence of a compromised antioxidant system, but this is not always consistent with specific observed parameters, which on the whole, show evidences of dysregulation. There are also controversies regarding the oxidative stress status in patients treated with typical vs. atypical antipsychotics.AimIn this context, the aim of the present work was to evaluate the specific activity of some peripheral antioxidant defences like superoxide dismutase (SOD) and glutathione peroxidase (GPX) and the level of a lipid peroxidation maker (malondialdehyde-MDA), in schizophrenic patients treated with typical (haloperidol) or atypical (olanzapine, quetiapine and risperidone) antipsychotics, compared with age-matched healthy subjects.MethodsThe subjects of this study (n = 45), consisted of 35 patients who met DSM-IV criteria for schizophrenia and 10 healthy control age and gender-matched subjects. Patients were of paranoid subtype, with duration of illness for at least 5 years. Nine patients were under haloperidol (1–2 mg daily dose) treatment and 26 (8/10/8) patients were under atypical treatment: quetiapine (300 mg daily dose), olanzapine (20 mg daily dose) or risperidone (2–4 mg daily dose), respectively.ResultsWe found a significant decrease in GPX specific activity and also a significant increase of MDA levels in schizophrenic patients, compared to age-matched control group, regardless of their type of treatment. Additionally, an increase in SOD specific activity was observed, mainly in the patients treated with haloperidol and quetiapine.ConclusionsFurther research is necessary in order to elucidate the effects of different antipsychotic agents on antioxidant enzymes.

Enzyme Activities and Histology Study on High Fat Diet-induced Obese Rats by Pink Guava Puree

The effects of pink guava (Psidium guajava) puree on enzyme activities and histology on High Fat Diet (HFD)-induced obese rats were investigated. Thirty male Sprague-Dawley rats were divided into Control Negative (CN) fed with rat pellet; control positive, low, medium and high dose group (CP, LDG, MDG and HDG) were fed HFD-AIN93G, respectively. CN and CP were given distilled water; meanwhile treated group were given the aqueous puree, at concentration of 500, 1000 and 2000 mg/kg body weight, dissolved in distilled water were administered orally via a drinking bottle, respectively. Pink guava puree was supplemented with the HFD diet for six weeks. The rats were fasted overnight and euthanized under an anesthetic condition with ethyl ether and blood was collected from the posterior vena cava at the end of experiment. A significant reduction in body weight was observed in the treated groups as compared to CN and CP group. Specific activities of Glutathione Peroxidase (GPx), Glutathione Reductase (GR) and Superoxide Dismutase (SOD) of the HFD-induced obese rats were significantly increased in compariso n with the CN group. Histologically, the liver and kidney cells in LDG, MDG and HDG showed no significant differences as compared to CN and CP's liver and kidney cells. Treatment with low, medium and high doses showed improved features in HFD induced-obese rat's liver and kidney cells. In conclusion, pink guava puree due to its antioxidant role was helpful in protecting organ tissues in experimental animals and has a significant impact on specific activities of HFD induced-obese rats.

Astrocytes retain their antioxidant capacity into advanced old age

Oxidative stress has been implicated in the progression of ageing and in many age-related neurodegenerative conditions. Astrocytes play a major role in the antioxidant protection of the brain, yet little is known about how the antioxidant defenses of astrocytes change across the lifespan. This study assessed the antioxidant capacity and glutathione metabolism of astrocytes cultured from the brains of neonatal (<24 h old), mature (12-month-old), old (25-month-old), and senescent (31-month-old) C57BL/6J mice. When exposed to 100 microM hydrogen peroxide, mature, old, and senescent astrocytes cleared the peroxide approximately 30% more slowly than neonatal astrocytes. This difference persisted when catalase was inhibited by 3-aminotriazole, but was abolished when glutathione was depleted by application of buthionine sulfoximine, suggesting a deficit in the glutathione system. Correspondingly, the specific glutathione reductase activity of mature, old, and senescent astrocytes was approximately 30% lower than that of neonatal cultures, whereas no age-related change was observed in the specific activities of glutathione peroxidase, catalase, or in total antioxidant capacity. In addition, the specific rate of glutathione export was almost identical in mature, old, and senescent astrocytes, but was more than double that of neonatal astrocytes. These results indicate that the antioxidant capacity and glutathione metabolism of astrocytes are preserved from mature adulthood into senescence. It is concluded that the oxidative stress seen in ageing brains is likely due to factors extrinsic to astrocytes, rather than to an impairment of the antioxidative functions of astrocytes.

Evaluation of antioxidant enzymes activities and lipid peroxidation in schizophrenic patients treated with typical and atypical antipsychotics

Studies performed in schizophrenia patients have generally suggested the presence of a compromised antioxidant system, but this is not always consistent with specific observed parameters, which on the whole, show evidences of dysregulation. There are also controversies regarding the oxidative stress status in patients treated with typical vs. atypical antipsychotics. In this context, the aim of the present work was to evaluate the specific activity of some peripheral antioxidant defences like superoxide dismutase (SOD) and glutathione peroxidase (GPX) and the level of a lipid peroxidation maker (malondialdehyde—MDA), in schizophrenic patients treated with typical (haloperidol) or atypical (olanzapine, quetiapine and risperidone) antipsychotics, compared with age-matched healthy subjects. We found a significant decrease in GPX specific activity and also a significant increase of MDA levels in schizophrenic patients, compared to age-matched control group, regardless of their type of treatment. Additionally, an increase in SOD specific activity was observed, mainly in the patients treated with haloperidol and quetiapine. Further research is necessary in order to elucidate the effects of different antipsychotic agents on antioxidant enzymes and lipid peroxidation or possible interventions at the oxidative stress level in schizophrenic patients.

Effects of serotonin depletion on behavior and neuronal oxidative stress status in rat: relevance for anxiety and affective disorders

We lesioned the hypothalamic paraventricular nucleus (PVN) of male Wistar rats using two different doses (8μg/3μl and 16μg/3μl) of 5,7-dihydroxytryptamine (5,7-DHT) and then animals were subjected to a battery of behavioral tests designed to assess anxiety and memory formation. Further, we were interested to know whether this lesion would result in neuronal oxidative stress and also if there is a correlation between the behavioral response to this lesion and brain oxidative stress. Behavioral tests included elevated plus maze, used to assess exploration/anxiety status and radial armmaze, used for determining spatial short-term and reference memory errors. Regarding the oxidative stress, we measured the extent of some lipid peroxidation products like malondialdehyde and defense enzymes such as superoxide dismutase and glutathione peroxidase. 5,7-DHT lesioned rats spent more time in the open arms of the elevated maze compared to sham-operated rats, suggesting that the lesion significantly diminished anxiety-like behavior. Also, short-term memory was significantly impaired, as shown by the working memory errors in radial arm-maze task. Further analyses revealed that the 5,7-DHT lesion did not result in a significant change of reference memory errors. Regarding the oxidative stress, no significant modification of both superoxide dismutase and glutathione peroxidase specific activities from the temporal lobe were observed. However, the malondiadehyde level was significantly increased, suggesting pro-oxidant effects. Also, the linear regression between the working memory errors vs. malondiadehyde resulted in significant correlations. 5,7 DHT lesion of the PVN affects behavioral performance via interactions with systems governing novel and/or fear-evoking situations and also by increasing neuronal oxidative stress.

Native specific activity of glutathione peroxidase (GPx‐1), phospholipid hydroperoxide glutathione peroxidase (PHGPx) and glutathione reductase (GR) does not differ between normo‐ and hypomotile human sperm samples

Native specific activity of glutathione peroxidase (GPx‐1), phospholipid hydroperoxide glutathione peroxidase (PHGPx) and glutathione reductase (GR) does not differ between normo‐ and hypomotile human sperm samples