自由基代谢与精神分裂症临床症状和药物治疗的关系

目的：探讨自由基代谢与精神分裂症临床症状和药物治疗的关系。方法：是否治疗的慢性精神分裂症患者各４０例分别评定定阳性和阴性症状量表（ＰＡＮＳＳ）,并测定膜脂质过氧化物丙二醛（ＭＤＡ）含量、铜／锌超氧化物歧化酶（Ｇｕ－ＺｎＳＯＤ）和谷胱苷肽过氧化物酶（ＧＳＨ－Ｐｘ）活性。结果：与健康对照组相比,未治疗组患者ＭＤＡ含量和ＧＳＨ－Ｐｘ活性显著增加,治疗组患者无显著改变;而两组患者ＳＯＤ活性显著降低;未治疗     

Serum Oxidative Stress Marker Levels in Unmedicated and Medicated Patients with Schizophrenia

Oxidative stress has been suggested to be involved in schizophrenia, but studies have demonstrated inconsistent results on oxidative stress marker level/activity in patients with schizophrenia. In order to clarify the circulating oxidative stress marker level/activity in patients with schizophrenia, this study recruited 80 schizophrenia patients (40 first-episode, drug-free and 40 chronically medicated patients) and 80 controls to analyze serum activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC), and levels of lipid peroxidation marker malondialdehyde (MDA) in schizophrenia patients, and whether they associate with the severity of the disease. We showed that only serum GSH-Px activity was significantly reduced in unmedicated patients with schizophrenia when compared with control subjects, whereas the other three analyzed oxidative stress markers did not show significant differences between cases and controls. Moreover, our results demonstrated that chronic medication increased GSH-Px activity and MDA levels in patients with schizophrenia, but reduced SOD activity in the patients. We also found that short-term antipsychotic treatments on the patients with schizophrenia reduced the SOD activity. Correlation analyses indicated that the oxidative stress marker activity/level is not significantly associated with the severity of schizophrenia, except that SOD level correlated with PANSS positive score significantly. Taken together, the data from the present study suggested that the dysfunctions of oxidative stress markers in patients with schizophrenia were mainly caused by antipsychotics, emphasizing increased oxidative stress as a potential side effect of antipsychotics on the patients.     

Bcl-2 associated with positive symptoms of schizophrenic patients in an acute phase

B cell lymphoma protein-2 (Bcl-2) may contribute to the pathophysiology of schizophrenia in the brain. The aim of this study was to investigate the serum levels of Bcl-2 in schizophrenic patients in an acute phase, and evaluate Bcl-2 level changes after antipsychotic treatment. We consecutively enrolled 41 schizophrenia patients in an acute phase; 28 were followed up with a 4-week antipsychotic treatment. Serum Bcl-2 levels were measured with assay kits. All patients were evaluated by examining the correlation between Bcl-2 levels and Positive and Negative Syndrome Scale (PANSS) scores, using Pearson correlation coefficients. In schizophrenic patients in an acute phase, positive PANSS subscores were significantly negatively correlated with Bcl-2 levels. In addition, we found Bcl-2 levels had a significantly negative correlation with PANSS total scores and positive subscores in male patients in an acute phase. Using the paired t-test, we found no significant changes in Bcl-2 levels in schizophrenia patients who had received the 4-week treatment with antipsychotic drugs (n=28). In conclusion, our results suggest that Bcl-2 might be an indicator of schizophrenia severity in the acute phase. In addition, Bcl-2 levels might be associated with positive symptoms in male patients with schizophrenia.     

Altered Antioxidant Defenses in Drug-Naive First Episode Patients with Schizophrenia Are Associated with Poor Treatment Response to Risperidone: 12-Week Results from a Prospective Longitudinal Study

Abnormal redox regulation is thought to contribute to schizophrenia (SCZ). Accumulating studies have shown that the plasma antioxidant enzyme activity is closely associated with the course and outcome in antipsychotics-naïve first-episode (ANFE) patients with SCZ. The main purpose of this study was to investigate the effect of risperidone on oxidative stress markers in ANFE patients and the relationship between risperidone response and changes in oxidative stress markers. Plasma activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) enzyme, total antioxidant status (TAS), and malondialdehyde (MDA) levels were measured in 354 ANFE patients and 152 healthy controls. The clinical symptoms were evaluated by the Positive and Negative Syndrome Scale (PANSS). Patients received risperidone monotherapy for 12 weeks and oxidative stress markers and PANSS were measured at baseline and at follow-up. Compared with healthy controls, the patients exhibited higher activities of SOD, CAT, and TAS levels, but lower MDA levels and GPx activity. A comparison between 168 responders and 50 non-responders at baseline and 12-week follow-up showed that GPx activity decreased in both groups after treatment. Moreover, GPx activity decreased less in responders and was higher in responders than in non-responders at follow-up. These results demonstrate that the redox regulatory system and antioxidant defense enzymes may have predictive value for the response of ANFE patients to risperidone treatment.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13311-021-01036-3.Key Words: Schizophrenia, Oxidative stress, Antioxidant defense system, Clinical response, Risperidone     

Antioxidant intervention attenuates oxidative stress in children and teenagers with Down syndrome

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 400 mg, 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.     

The Combined Effect of Sleep Deprivation and Western Diet on Spatial Learning and Memory: Role of BDNF and Oxidative Stress

Either sleep deprivation or Western diet can impair learning and memory via induction of oxidative stress, which results in neuronal damage and interference with the neurotransmission. In this study, we examined the combined effect of sleep deprivation and Western diet on hippocampus-dependent spatial learning and memory. In addition, possible molecular targets for sleep deprivation and Western diet-induced cognitive impairments were investigated. Sleep deprivation was induced in rats using the modified multiple platform model simultaneous with the administration of Western diet for 6 weeks. Thereafter, spatial learning and memory were tested using radial arm water maze. At the molecular level, BDNF protein and antioxidant markers including superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG, and thiobarbituric acid reactive substances (TBARS) were assessed. The results of this study revealed that sleep deprivation, Western diet, or a combination of both impair short- and long-term memory (P?<?0.05). The magnitude of the impairment induced by the combined treatment at the 24-h long-term memory was higher than that caused by each factor alone (P?<?0.05). In addition, the combined treatment reduced the levels of hippocampal BDNF, a reduction that was not detected with each factor alone. Moreover, the combined treatment reduced the hippocampal activities of SOD, catalase, GPx, ratio of GSH/GSSG, and elevated TBARS level (P?<?0.05). In conclusion, the combination of sleep deprivation and Western diet decreases BDNF levels and increases oxidative stress in the hippocampus, thus inducing memory impairment that is greater than the impairment produced by each factor alone.     

Risperidone reverses phencyclidine induced decrease in glutathione levels and alterations of antioxidant defense in rat brain

Perinatal phencyclidine (PCP) administration to rats represents one of the actual animal models of schizophrenia. Numerous data suggest redox dysregulation in this disease. We have previously demonstrated decreased content of the reduced glutathione (GSH) and complex disbalance of antioxidant enzymes in the brain of rats perinatally treated with PCP. The aim of this study was to elucidate whether chronic risperidone treatment can reverse these changes. The Wistar rats were perinatally treated with either PCP (10mg/kg; PCP, two groups) or saline (0.9% NaCl, two groups). At postnatal day (PN) 35, two groups of rats one NaCl and one PCP have started to receive risperidone in drinking water for nine weeks (NaCl-RSP and PCP-RSP groups). Animals were sacrificed on PN100 and the levels of GSH, the activities of γ-glutamate cysteine ligase (GCL), glutathione peroxidase (GPx), glutathione reductase (GR) and superoxide dismutase (SOD), as well as, the concentration of lipid peroxides were determined in the different brain structures. Risperidone restored decreased GSH levels, as well as decreased γ-GCL activity in cortex and hippocampus of animals perinatally treated with PCP. Alterations in GPx and GR activities caused by perinatal PCP treatment were also reversed by risperidone in most investigated brain structures. Furthermore, chronic risperidone treatment caused the decrease in SOD activity both in control and in PCP perinatally treated groups. Increased levels of lipid peroxides noticed in hippocampus and thalamus were reversed after chronic risperidone treatment. The results of the present study demonstrate that risperidone treatment restores GSH levels and to great measure reverses antioxidant defense alterations in the brain of perinatally PCP treated rats. Further studies are necessary in order to clarify the significance of risperidone influence on oxidative stress parameters in schizophrenia.     

Elevated plasma superoxide dismutase in first-episode and drug naive patients with schizophrenia: inverse association with positive symptoms

Excessive free radical production or oxidative stress may be involved in the pathophysiology of schizophrenia as evidenced by increased superoxide dismutase (SOD) activities, a critical enzyme in the detoxification of superoxide radicals. This study compared plasma SOD activities in 78 never-medicated first-episode and 100 medicated chronic schizophrenia patients to 100 healthy control subjects and correlated these SOD activities with the Positive and Negative Syndrome Scale (PANSS) among the schizophrenic patients. We found that both first-episode and chronic patients had significantly increased plasma SOD activities compared to controls, and that chronic schizophrenic patients on antipsychotic medication had significantly higher SOD activities than first episode schizophrenic patients. Plasma SOD activities were also negatively correlated with positive symptoms of schizophrenia, but only in first-episode patients. Thus, oxidative stress appears to be greater in first episode schizophrenic patients with fewer positive symptoms and may become greater as schizophrenia becomes more chronic, although we cannot exclude the possibility that chronic antipsychotic treatment may increase SOD activities and presumed oxidative stress in schizophrenia.     

Decreased antioxidant enzymes and membrane essential polyunsaturated fatty acids in schizophrenic and bipolar mood disorder patients

Oxidative stress-mediated cell damage has been considered in the pathophysiology of schizophrenia. Abnormal findings have often been considered related to differences in ethnicity, life style, dietary patterns and medications, all of which influence indices of oxidative stress and oxidative cell damage. To minimize these confounds, schizophrenic patients were compared with age-matched control subjects with the same ethnic background and similar lifestyle, as well as with bipolar mood disorder (BMD) patients. Levels of antioxidant defense enzymes (i.e. superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GPx) were lower in schizophrenic patients than in controls, indicating conditions for increased oxidative stress. The contents of plasma thiobarbituric acid reactive substances (TBARS) were only marginally higher in schizophrenic patients, who had normal levels of arachidonic acid (AA), a major source of TBARS, indicating no significant oxidative membrane lipid peroxidation. Levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), however, were significantly lower in schizophrenic patients. When the same indices in BMD patients were compared with findings in matched controls, levels of only SOD and CAT were lower in the patients, whereas GPx was not. Again, as in schizophrenia, the contents of TBARS were marginally higher in BMD patients with no change in levels of AA. Levels of alpha-linolenic acid and EPA were significantly lower and levels of DHA were slightly lower in BMD patients. These data indicate that certain biochemical characteristics may be common to a spectrum of psychiatric disorders, and suggest supplementation of antioxidants and essential fatty acids might affect clinical outcome.     

Serum S100B and antioxidant enzymes in bipolar patients

Bipolar disorder (BD) is a chronic, severe, and highly disabling psychiatric disorder; peripheral markers have been used to assess biochemical alterations associated with BD and/or possibly involved in its pathophysiology. Beyond neuronal commitment, many groups have proposed the involvement of glial activity in psychiatric disorders. Other biochemical markers, particularly associated with oxidative stress, have been studied in BD. In the present study, we evaluated glial involvement and oxidative stress in patients with BD. Glial activity was assessed by measuring serum S100B content; oxidative stress was assessed using serum thiobarbituric acid reactive substances (TBARS) and activities of antioxidant enzymes in BD patients during different episodes of disease. We found a significant increment of serum S100B during episodes of mania and depression, but not in euthymic patients. Superoxide dismutase (SOD) activity, as well the SOD/glutathione peroxidase plus catalase ratio, was also increased in manic and depressed patients. On the other hand, TBARS levels were increased in BD patients regardless of the phase of the disorder. These findings suggest a potential oxidative damage in BD patients. This peripheral oxidative imbalance indicates that systemic changes are taking place during the active phases of the illness. Such changes appear to relate to astrocyte function, as indicated by serum S100B elevation.     

Persistence of the benefit of an antioxidant therapy in children and teenagers with Down syndrome

This study examined the effect of an antioxidant intervention in biomarkers of inflammation and oxidative stress (OS) in the blood of Down syndrome (DS) children and teenagers during four different stages. A control group was composed by healthy children (n = 18), assessed once, and a Down group composed by DS patients (n = 21) assessed at the basal period (t₀), as well as after 6 months of antioxidant supplementation (t₁), after 12 months (after interruption of the antioxidant intervention for 6 months) (t₂), and again after further 6 months of antioxidant supplementation (t₃). Biomarkers of inflammation (myeloperoxidase activity – MPO and levels of IL-1β and TNF-α) and OS (thiobarbituric acid reactive substances – TBARS, protein carbonyls – PC), reduced glutathione (GSH), uric acid (UA) and vitamin E levels, as well as antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST) and gamma-glutamyltransferase (GGT) activities, were measured after each period. After the antioxidant supplementation, the activities of SOD, CAT, GPx, GR, GGT and MPO were downregulated, while TBARS contents were strongly decreased, the contents of GSH and vitamin E were significantly increased, and no changes in G6PD and GST activity as well as in UA and PC levels were detected. After the interruption of the antioxidant therapy for 6 months, DS patients showed elevated GPx and GGT activities and also elevated UA and TBARS levels. No changes in SOD, CAT, GR, GST, G6PD and MPO activities as well as in GSH, vitamin E, PC, TNF-α and IL-1β levels were detected. The results showed that the antioxidant intervention persistently attenuated the systemic oxidative damage in DS patients even after a relatively long period of cessation of the antioxidant intervention.     

大剂量维生素C和维生素E对急性颅脑损伤病人神经损伤、神经营养及氧化应激的影响

目的 探讨大剂量维生素C和维生素E对急性颅脑损伤病人神经损伤、神经营养及氧化应激的影响。方法 2018年1月至2018年11月前瞻性收集84例急性颅脑损伤并随机分为对照组（n=42,接受常规治疗）和观察组（n=42,接受大剂量维生素C和维生素E联合常规治疗）。治疗前、治疗后4、7 d,采用酶联免疫吸附法测定血清神经损伤指标[包括神经元特异性烯醇化酶（NSE）、S100蛋白、脑红蛋白（NGB）、泛素羧基末端水解酶L1（UCH-L1））、神经营养指标[包括神经营养因子-α（NTF-α）、脑源性神经营养因子（BDNF）、神经生长因子（NGF）、胰岛素样生长因子-1（IGF-I）,采用放射免疫沉淀法测定氧化应激指标[包括超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GPx）、过氧化氢酶（CAT）、丙二醛（MDA）、晚期氧化蛋白产物（AOPP）]。结果 治疗后4、7 d,两组血清NSE、S100B、NGB、UCH-L1、MDA、AOPP含量均显著降低（P<0.05）,血清NTF-α、BDNF、NGF、IGF-I、SOD、GPx、CAT含量均显著增高（P<0.05）,而且,观察组均明显优于对照组（P<0.05）。结论 大剂量维生素C和维生素E治疗能够减轻急性颅脑损伤病人神经损伤程度、氧化应激反应并改善神经营养状态。     

The indices of endogenous oxidative and antioxidative processes in plasma from schizophrenic patients. The possible role of oxidant/antioxidant imbalance

There is great evidence in recent years that oxygen free radicals play an important role in the pathophysiology of schizophrenia. The present study was performed to assess the changes in plasma nitric oxide (NO) and thiobarbituric acid-reactive substances (TBARS) levels, and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and xanthine oxidase (XO) activities in schizophrenic patients compared to age- and sex-matched normal controls. A hundred patients with schizophrenia and 51 healthy volunteers were included in the study. XO, SOD, and GSH-Px activities as well as NO and TBARS levels were estimated by standard biochemical techniques in the plasma of normal healthy controls and schizophrenia patients. In schizophrenia, increased plasma XO activity (P < .0001) and NO levels (P < .0001), decreased SOD activity (P < .0001), and unchanged GSH-Px activity were detected compared to control group. Plasma TBARS levels were increased in schizophrenic patients (P < .01), especially in the residual subtype. TBARS levels in nonsmoker schizophrenic patients were found to be higher than nonsmoker controls. Although TBARS levels in both patients and controls were found to be higher in smokers as compared to nonsmokers, it was not statistically significant. No effects of duration of the illness, gender, and low and high dose of daily neuroleptic treatment equivalent to chlorpromazine on oxidant and antioxidant parameters were observed. Because the dose and the duration of treatment with drugs have no influence on the results, it can be interpreted that the findings are more likely to be related mainly to the underlying disease. These findings indicated a possible role of increased oxidative stress and diminished enzymatic antioxidants, both of which may be relevant to the pathophysiology of schizophrenia. On the other hand, increased NO production by nitric oxide synthetases (NOSs) suggests a possible role of NO in the pathophysiological process of schizophrenia. These findings may also suggest some clues for the new treatment strategies with antioxidants and NO synthase (NOS) inhibitors in schizophrenia.     

Erythrocyte indicators of oxidative changes in patients with graded traumatic head injury

Context: Acute oxidative stress following a traumatic head injury (HI) has been implicated in inducing severe secondary brain damage and influencing the clinical outcome of HI patients. Aims: This study was performed to evaluate and compare the oxidative changes in patients with varying severity of HI in the early posttraumatic period using erythrocyte indicators. Settings and Design: Head injury patients were divided into two groups based on their Glasgow Coma Scale (GCS) scores recorded at admission to the hospital on the day of trauma itself. Accordingly, the study included 30 severe HI (SHI, GCS scores 8 or less) and 25 Mild HI (MHI, GCS scores more than 8) patients. Thirty age and sex-matched healthy individuals were included in this comparative study as controls. Materials and Methods: Blood samples were obtained from controls and HI patients (within 24 h of trauma onset). Erythrocyte oxidative changes were studied by estimating thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD) and glutathione reductase (GR). Results: Erythrocyte TBARS levels were significantly higher and GSH levels were significantly lower in SHI and MHI patients as compared to controls. The SOD activity was significantly increased only in SHI patients and remained unchanged in MHI patients as compared to controls. As compared to MHI patients, erythrocyte TBARS levels were significantly higher, GSH levels were significantly lower and SOD activity was markedly elevated in SHI patients. Erythrocyte GR activity did not show significant changes in both groups of patients as compared to controls. Conclusion: Oxidative stress is evident in both SHI and MHI patients in the early posttraumatic period as reflected by their erythrocyte indicators, but the severity of oxidative stress has varied relatively with the severity of head injury. The present findings provide indications that early oxidative changes could influence the neurological recovery of HI patients.     

Chronic variable stress induces oxidative stress and decreases butyrylcholinesterase activity in blood of rats

Depressive disorders, including major depression, are serious and disabling, whose mechanisms are not clearly understood. Since life stressors contribute in some fashion to depression, chronic variable stress (CVS) has been used as an animal model of depression. In the present study we evaluated some parameters of oxidative stress [thiobarbituric acid reactive substances (TBARS), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)], and inflammatory markers (interleukin 6, C reactive protein, tumor necrosis factor-alpha and nitrites), as well as the activity of butyrylcholinesterase in blood of rats subjected to chronic stress. Homocysteine and folate levels also were measured. Stressed animals were submitted to different mild stressors for 40 days. After CVS, a reduction in weight gain was observed in the stressed group, as well as an increase in immobility time in the forced swimming test as compared with controls. Stressed animals presented a significant increase on TBARS and SOD/CAT ratio, but stress did not alter GPx activity and any inflammatory parameters studied. CVS caused a significant inhibition on serum butyrylcholinesterase activity. Stressed rats had higher plasmatic levels of homocysteine without differences in folate levels. Although it is difficult to extrapolate our findings to the human condition, the alterations observed in this work may be useful to help to understand, at least in part, the pathophysiology of depressive disorders.     

Pro-oxidant status based alterations in cerebellar antioxidant response to aluminum insult

Cerebellum is unique in restraining amyloid-induced neurodegenerative changes. Amyloidosis and oxidant imbalance is common in aluminum exposure. Interestingly, aluminum itself does not pose any redox activity still it is associated with oxidant imbalance, and, it can aggravate the situation of already existing oxidant threat. Male rats were exposed to aluminum for 4 weeks along with exposure to 4 different doses of ethanol. After the treatment period, cerebellar level of protein, reduced glutathione (GSH), lipid perioxidation (TBARS) were measured. Activities of catalase, superoxide dismutase (SOD), glutathione reductase (GR) and glutathione perioxidase (GPx) were also estimated from the homogenized cerebellar tissue. In the present regimen of aluminum exposure, the cerebellum has shown significant reduction only in GPx activity. However, when aluminum was coexposed with ethanol, it contributed significantly to increase the cerebellar oxidant imbalance by (a) compromising the GSH restoration system, (b) reducing enzymatic peroxide scavenging system of cerebellum, (c) restricting the capability to cope with oxidative stress, as well as (d) downgrading the resistance to oxidative damage in response to chemical stress. Present study demonstrates that coexposure of aluminum with pro-oxidant favored development of aluminum-induced oxidative stress in cerebellum. These observations enlighten the role of pro-oxidants in the process of oxidative degeneration of cerebellum. With further studies, the present observation can be useful to understand the mechanism of neurodegenerative disorders and ways to ameliorate them.     

Oxidative-antioxidative systems and their relation with serum S100 B levels in patients with schizophrenia: effects of short term antipsychotic treatment

Oxidative stress may be a contributing factor in the etiopathophysiology of schizophrenia, which may be exacerbated by the treatment with antipsychotics with pro-oxidant properties. Increased levels of S100 B are associated with neurodegenerative disorders, including schizophrenia. The aim of the present study was to investigate the role of oxidative cell damage in the pathogenesis of schizophrenia. Forty patients who fully met the fourth Diagnostic and Statistical Manual of Mental Disorders criteria for schizophrenia and 35 healthy control subjects were included in the study. Serum S100 B level was determined to investigate brain damage. Plasma malondialdehyde (MDA) levels and susceptibility of red blood cell (RBC) to oxidation were determined to investigate the oxidative status and plasma vitamin E, vitamin C, serum total carotenoid levels and total antioxidant capacity and RBC superoxide dismutase (SOD) and whole blood glutathione peroxidase activities were measured to investigate the antioxidative defence before and after 6 weeks of antipsychotic treatment. Plasma MDA and serum S100 B levels and RBC-SOD activity were significantly higher in the schizophrenia group than those of the control group. Treatment did not modify any of the oxidative-antioxidative system parameters or serum S100 B levels. S100 B level was significantly higher in patients with negative symptoms than the patients with positive symptoms and the control subjects. S100 B levels were significantly reduced after 6 weeks of treatment in patients with negative symptoms. The results of the present study might support the oxidative cell injury hypothesis of the schizophrenia. Furthermore, the underlying mechanisms of the subgroups of schizophrenia might be different as suggested by the increased S100 B levels and its decrement after treatment in patients with negative symptoms.     

Peripheral oxidative stress biomarkers in mild cognitive impairment and Alzheimer's disease

Oxidative stress has been associated with normal aging and Alzheimer's disease (AD). However, little is known about oxidative stress in mild cognitive impairment (MCI) patients who present a high risk for developing AD. The aim of this study was to investigate plasma production of the lipid peroxidation marker, malonaldehyde (MDA) and to determine, in erythrocytes, the enzymatic antioxidant activity of catalase, glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST) in 33 individuals with MCI, 29 with mild probable AD and 26 healthy aged subjects. GR/GPx activity ratio was calculated to better assess antioxidant defenses. The relationship between oxidative stress and cognitive performance was also evaluated by the Mini Mental State Examination (MMSE). AD patients showed higher MDA levels than both MCI and healthy elderly subjects. MCI subjects also exhibited higher MDA levels compared to controls. Catalase and GPx activity were similar in MCI and healthy individuals but higher in AD. GR activity was lower in MCI and AD patients than in healthy aged subjects. Additionally, GR/GPx ratio was higher in healthy aged subjects, intermediate in MCI and lower in AD patients. No differences in GST activity were detected among the groups. MMSE was negatively associated with MDA levels (r = -0.31, p = 0.028) and positively correlated with GR/GPx ratio in AD patients (r = 0.68, p < 0.001). MDA levels were also negatively correlated to GR/GPx ratio (r = -0.31, p = 0.029) in the AD group. These results suggest that high lipid peroxidation and decreased antioxidant defenses may be present early in cognitive disorders.     

Antioxidant status in acute stroke patients and patients at stroke risk

BACKGROUND AND PURPOSE: Antioxidant enzymes like copper/zinc superoxide dismutase (SOD), catalase and gluthatione peroxidase (GSHPx) are part of intracellular protection mechanisms to overcome oxidative stress and are known to be activated in vascular diseases and acute stroke. We investigated the differences of antioxidant capacity in acute stroke and stroke risk patients to elucidate whether the differences are a result of chronic low availability in arteriosclerosis and stroke risk or due to changes during acute infarction. METHODS: Antioxidant enzymes were examined in 11 patients within the first hours and days after acute ischemic stroke and compared to risk- and age-matched patients with a history of stroke in the past 12 months (n = 17). Antioxidant profile was determined by measurement of glutathione (GSH), malondialdehyde (MDA), SOD, GSHPx and minerals known to be involved in antioxidant enzyme activation like selenium, iron, copper and zinc. RESULTS: In comparison to stroke risk patients, patients with acute ischemic stroke had significant changes of the GSH system during the first hours and days after the event: GSH was significantly elevated in the first hours (p < 0.01) and GSHPx was elevated 1 day after the acute stroke (p < 0.05). Selenium, a cofactor of GSHPx, was decreased (p < 0.01). GSHPx levels were negatively correlated with National Institutes of Health Stroke Scale (NIHSS) scores on admission (r = -0.84, p < 0.001) and NIHSS scores after 7 days (r = -0.63, p < 0.05). MDA levels showed a trend for elevation in the first 6 h after the acute stroke (p = 0.07). No significant differences of SOD, iron, copper nor zinc levels could be identified. CONCLUSIONS: Differences of antioxidant capacity were found for the GSH system with elevation of GSH and GSHPx after acute stroke, but not for other markers. The findings support the hypothesis that changes of antioxidant capacity are part of acute adaptive mechanisms during acute stroke.     

Oxidative stress in acute ischemic stroke.

Oxidative stress plays an important role in acute ischemic stroke pathogenesis. Free radical formation and subsequent oxidative damage may be a factor in stroke severity. Serum levels of nitric oxide (NO), malondialdehyde (MDA) and glutathione (GSH) were measured within the first 48 h of stroke in 70 patients. The levels were also correlated with the clinical outcomes using Canadian Neurological Scale (CNS) scores. The results were compared with a control group consisting of 70 volunteers with similar stroke risk factors. Serum NO, MDA and GSH levels were significantly elevated in acute stroke patients. CNS score was negatively correlated with both MDA and NO levels. However, no statistically significant correlation between GSH levels and CNS scores was detected. Our results suggest deleterious effects of oxidative stress on clinical outcome in acute ischemic stroke. The elevation of GSH levels may be an adaptive mechanism during this period.