Antipsychotic Treatment Reduces Indices of Oxidative Stress in First-Episode Psychosis Patients

Dietary total antioxidant capacity and serum 8-OHdG in patients with schizophrenia

BACKGROUND

Dietary total antioxidant capacity serves as an indicator for dietary quality and reflects daily antioxidant intake. This study aimed to determine the oxidative stress status of patients with schizophrenia and to examine the relationship between dietary total antioxidant capacity (dTAC) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker for oxidative stress.

METHODS

This study was conducted in Turkey and involved 40 patients diagnosed with schizophrenia or schizoaffective disorder according to the Diagnostic and Statistical Manual of Mental Disorders, 5th ed., and 30 healthy controls matched for age and gender. The participants' sociodemographic characteristics and nutritional habits were determined through face-to-face interviews and through the use of questionnaires. The dTAC and dietary oxidative balance scores were calculated using a three-day dietary intake record. 8-OHdG levels were analyzed in the serum samples collected from the subjects.

RESULTS

Dietary ferric reducing antioxidant power (FRAP-1, FRAP-2), Trolox equivalence antioxidant capacity (TEAC), and oxygen radical absorbance capacity (H-ORAC) values were lower in patients with schizophrenia than in the healthy controls (P < 0.05). Serum 8-OHdG levels were found similar in both groups (P > 0.05).

CONCLUSION

Nutritional interventions are needed in patients with schizophrenia given that insufficient antioxidant intake may increase oxidative stress, which in turn affects disease development. Therefore, healthy nutrition, especially sufficient intake of dietary antioxidants, should be encouraged in patients with schizophrenia.

Assessing the relationship between antipsychotic drug use and prolidase enzyme activity and oxidative stress in schizophrenia patients: a case-control study

BACKGROUND

The relationship between proline, its association with oxidative stress, and its connection to schizophrenia is a subject that has not been sufficiently investigated.

OBJECTIVE

The aim of this study is to evaluate the possible effects of atypical and combined (typical and atypical) antipsychotic use on serum prolidase enzyme activity (SPEA) and serum oxidative stress parameters, and to assess the relationship between SPEA and oxidative stress in patients with schizophrenia.

METHODS

A total of 57 patients with schizophrenia, of which 34 were using atypical (AAPG) and 23 were using combined (typical and atypical) (CAPG) antipsychotic therapy, and 28 healthy volunteers (control group) were included in this case-control study.

RESULTS

SPEA levels of AAPG and CAPG were significantly lower than that of control group ( P  = 0.003). The oxidative stress index (OSI) value of AAPG was significantly higher than the other two groups ( P  = 0.001). SPEA (<1860 U/l) and OSI (≥0.54) could discriminate schizophrenia patients with antipsychotic therapy from control groups ( P  = 0.001 and P  = 0.007, respectively). Lower SPEA levels were associated with antipsychotic use ( P  = 0.007).

CONCLUSION

The SPEA values of patients with schizophrenia on antipsychotics were significantly lower compared to controls. OSI values were significantly higher in atypical antipsychotic recipients compared to those on combined antipsychotics and healthy controls.

Increased levels of lipid and protein oxidation in rat prefrontal cortex after treatment by lithium, valproic acid, and olanzapine

Oxidative stress is widely accepted to contribute to the pathogenesis of several psychiatric diseases. Many antipsychotic drugs and mood stabilizers act through restoration of the dysregulated oxidative homeostasis in the brain. However, the long-term effect of these drugs per se in terms of their potential to interfere with the oxidative status in the brain remains largely controversial. The present study aimed to investigate the sole effect of three commonly used psychoactive drugs, lithium, valproic acid, and olanzapine, on lipid and protein oxidation status in the prefrontal cortex of healthy rats. A total of 80 adult male albino Wistar rats were used, and groups were treated with saline (control), lithium, valproic acid, or olanzapine daily for 30 days. Following sacrification, right prefrontal cortexes were dissected and homogenized. Lipid peroxidation (LPO) and protein oxidation (AOPP) assays were performed by ELISA. LPO levels were significantly higher in lithium and valproic acid-treated rats by 45% and 40%, respectively. Olanzapine treatment caused a mild 26% increase in LPO levels, but the effect was non-significant. Lithium, valproic acid, and olanzapine treatments significantly increased AOPP levels by 58%, 54%, and 36.5%, respectively. There was a strong positive correlation between the lipid peroxidation and protein oxidation levels. Our results call attention to the need to consider the pro-oxidative capacity of antipsychotic drugs per se and their potential to disturb the oxidative homeostasis in the brain during long-term medication for psychiatric diseases.

Benefits and Meaning of Lipids Profile in Relation to Oxidative Balance and Brain Morphology in Schizophrenia

Schizophrenia is characterized by complex metabolic dysregulations and their consequences. Until now, numerous theories have explained its pathogenesis, using a spectrum of available technologies. We focused our interest on lipid profile-periphery high-density cholesterol level and lipoproteins in the human brain and compared magnetic resonance imaging (MRI) scans of patients with schizophrenia and the healthy group. Detailed analysis of biochemical parameters was performed using magnetic resonance spectroscopy. Our study aimed to reveal correlations between periphery high-density lipoproteins levels and lipoproteins in the brain, depicted in MRI scans, and parameters of peripheral oxidative stress expressed as paraoxonase. Patients with schizophrenia have decreased levels of high-density lipoproteins, low paraoxonase activity, and slightly raised sodium in the blood. Positive significant correlations between serum high-density cholesterol and anterior cingulate cortex, unique brain area for schizophrenia pathophysiology, MR spectroscopy signals, and diffusion have been revealed. To our knowledge, this is the first study to describe the effect of an anterior cingulate disorder on high-density cholesterol levels on the development of schizophrenia.

Oxidative Stress and Emergence of Psychosis

Treatment and prevention strategies for schizophrenia require knowledge about the mechanisms involved in the psychotic transition. Increasing evidence suggests a redox imbalance in schizophrenia patients. This narrative review presents an overview of the scientific literature regarding blood oxidative stress markers’ evolution in the early stages of psychosis and chronic patients. Studies investigating peripheral levels of oxidative stress in schizophrenia patients, first episode of psychosis or UHR individuals were considered. A total of 76 peer-reviewed articles published from 1991 to 2022 on PubMed and EMBASE were included. Schizophrenia patients present with increased levels of oxidative damage to lipids in the blood, and decreased levels of non-enzymatic antioxidants. Genetic studies provide evidence for altered antioxidant functions in patients. Antioxidant blood levels are decreased before psychosis onset and blood levels of oxidative stress correlate with symptoms severity in patients. Finally, adjunct treatment of antipsychotics with the antioxidant N-acetyl cysteine appears to be effective in schizophrenia patients. Further studies are required to assess its efficacy as a prevention strategy. Redox imbalance might contribute to the pathophysiology of emerging psychosis and could serve as a therapeutic target for preventive or adjunctive therapies, as well as biomarkers of disease progression.

Plasma linoelaidyl carnitine levels positively correlated with symptom improvement in olanzapine-treated first-episode drug-naïve schizophrenia

INTRODUCTION

Olanzapine (OLA) is one of the most commonly used second-generation antipsychotics for the treatment of schizophrenia. However, the heterogeneity of therapeutic response to OLA among schizophrenia patients deserves further exploration. The role of carnitine in the clinical response to OLA monotherapy remains unclear.

OBJECTIVES

The current study was designed to investigate whether carnitine and its derivatives are linked to the response to OLA treatment. Drug-naïve first-episode patients with schizophrenia were recruited and treated with OLA for 4 weeks. Psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS) in pre and post treatment.

RESULTS

After treatment, we found a significant decrease in 2-Octenoylcarnitine levels and a significant increase in linoelaidyl carnitine, 11Z-Octadecenylcarnitine and 9-Decenoylcarnitine levels. Furthermore, baseline linoelaidyl carnitine levels were correlated with the reduction of PANSS positive symptom subscore. Linear regression and logistic regression analyses found that the baseline linoelaidyl carnitine level was a predictive marker for the therapeutic response to OLA monotherapy for 4 weeks.

CONCLUSION

Our pilot study suggests that linoelaidyl carnitine levels at baseline may have a predictive role for the improvement of positive symptoms after OLA monotherapy in the patients with schizophrenia.

Recent Reports on Redox Stress-Induced Mitochondrial DNA Variations, Neuroglial Interactions, and NMDA Receptor System in Pathophysiology of Schizophrenia

Schizophrenia (SZ) is a chronic psychiatric disorder affecting several people worldwide. Mitochondrial DNA (mtDNA) variations could invoke changes in the OXPHOS system, calcium buffering, and ROS production, which have significant implications for glial cell survival during SZ. Oxidative stress has been implicated in glial cells-mediated pathogenesis of SZ; the brain comparatively more prone to oxidative damage through NMDAR. A confluence of scientific evidence points to mtDNA alterations, Nrf2 signaling, dynamic alterations in dorsolateral prefrontal cortex (DLPFC), and provocation of oxidative stress that enhance pathophysiology of SZ. Furthermore, the alterations in excitatory signaling related to NMDAR signaling were particularly reported for SZ pathophysiology. Current review reported the recent evidence for the role of mtDNA variations and oxidative stress in relation to pathophysiology of SZ, NMDAR hypofunction, and glutathione deficiency. NMDAR system is influenced by redox dysregulation in oxidative stress, inflammation, and antioxidant mediators. Several studies have demonstrated the relationship of these variables on severity of pathophysiology in SZ. An extensive literature search was conducted using Medline, PubMed, PsycINFO, CINAHL PLUS, BIOSIS Preview, Google scholar, and Cochrane databases. We summarize consistent evidence pointing out a plausible model that may elucidate the crosstalk between mtDNA alterations in glial cells and redox dysregulation during oxidative stress and the perturbation of NMDA neurotransmitter system during current therapeutic modalities for the SZ treatment. This review can be beneficial for the development of promising novel diagnostics, and therapeutic modalities by ascertaining the mtDNA variations, redox state, and efficacy of pharmacological agents to mitigate redox dysregulation and augment NMDAR function to treat cognitive and behavioral symptoms in SZ.

Oxidative Stress-Related Mechanisms in Schizophrenia Pathogenesis and New Treatment Perspectives

Schizophrenia is recognized to be a highly heterogeneous disease at various levels, from genetics to clinical manifestations and treatment sensitivity. This heterogeneity is also reflected in the variety of oxidative stress-related mechanisms contributing to the phenotypic realization and manifestation of schizophrenia. At the molecular level, these mechanisms are supposed to include genetic causes that increase the susceptibility of individuals to oxidative stress and lead to gene expression dysregulation caused by abnormal regulation of redox-sensitive transcriptional factors, noncoding RNAs, and epigenetic mechanisms favored by environmental insults. These changes form the basis of the prooxidant state and lead to altered redox signaling related to glutathione deficiency and impaired expression and function of redox-sensitive transcriptional factors (Nrf2, NF-κB, FoxO, etc.). At the cellular level, these changes lead to mitochondrial dysfunction and metabolic abnormalities that contribute to aberrant neuronal development, abnormal myelination, neurotransmitter anomalies, and dysfunction of parvalbumin-positive interneurons. Immune dysfunction also contributes to redox imbalance. At the whole-organism level, all these mechanisms ultimately contribute to the manifestation and development of schizophrenia. In this review, we consider oxidative stress-related mechanisms and new treatment perspectives associated with the correction of redox imbalance in schizophrenia. We suggest that not only antioxidants but also redox-regulated transcription factor-targeting drugs (including Nrf2 and FoxO activators or NF-κB inhibitors) have great promise in schizophrenia. But it is necessary to develop the stratification criteria of schizophrenia patients based on oxidative stress-related markers for the administration of redox-correcting treatment.

Accumulation rate of advanced glycation end products in recent onset psychosis: A longitudinal study

Schizophrenia is associated with excessive oxidative stress. Production of advanced glycation end products (AGEs) in the skin is strongly associated with oxidative stress. Increased skin AGE-levels have been demonstrated at cross-sectional level in recent onset psychosis and chronic schizophrenia, indicating increased cardiovascular risk. We aimed to investigate factors underlying AGE-accumulation and accumulation rate of AGEs in recent onset psychosis. From December 2016 through May 2017, 66 patients and 160 (highly educated) healthy controls from a previous case-control study of AGE-levels were assessed for a follow-up measurement 12-24 months after baseline. Possible determinants of AGE-accumulation were analyzed. AGE-accumulation rates in patients and controls were compared adjusted for relevant confounders. In healthy controls, a significant association of AGE-accumulation with ethnicity and tobacco exposure was found. An indication of a markedly higher AGE-accumulation rate was found in patients suffering from recent onset psychosis compared to healthy controls, independent of ethnicity and tobacco smoking, but not independent of cannabis use (more prevalent in patients than controls), although results were not significant.

Antioxidant Potential of Psychotropic Drugs: From Clinical Evidence to In Vitro and In Vivo Assessment and toward a New Challenge for in Silico Molecular Design

Due to high oxygen consumption, the brain is particularly vulnerable to oxidative stress, which is considered an important element in the etiopathogenesis of several mental disorders, including schizophrenia, depression and dependencies. Despite the fact that it is not established yet whether oxidative stress is a cause or a consequence of clinic manifestations, the intake of antioxidant supplements in combination with the psychotropic therapy constitutes a valuable solution in patients' treatment. Anyway, some drugs possess antioxidant capacity themselves and this aspect is discussed in this review, focusing on antipsychotics and antidepressants. In the context of a collection of clinical observations, in vitro and in vivo results are critically reported, often highlighting controversial aspects. Finally, a new challenge is discussed, i.e., the possibility of assessing in silico the antioxidant potential of these drugs, exploiting computational chemistry methodologies and machine learning. Despite the physiological environment being incredibly complex and the detection of meaningful oxidative stress biomarkers being all but an easy task, a rigorous and systematic analysis of the structural and reactivity properties of antioxidant drugs seems to be a promising route to better interpret therapeutic outcomes and provide elements for the rational design of novel drugs.

Lowered Antioxidant Defenses and Increased Oxidative Toxicity Are Hallmarks of Deficit Schizophrenia: a Nomothetic Network Psychiatry Approach

There is now evidence that schizophrenia and deficit schizophrenia are neuro-immune conditions and that oxidative stress toxicity (OSTOX) may play a pathophysiological role. Aims of the study: to compare OSTOX biomarkers and antioxidant (ANTIOX) defenses in deficit versus non-deficit schizophrenia. We examined lipid hydroperoxides (LOOH), malondialdehyde (MDA), advanced oxidation protein products (AOPP), sulfhydryl (-SH) groups, paraoxonase 1 (PON1) activity and PON1 Q192R genotypes, and total radical-trapping antioxidant parameter (TRAP) as well as immune biomarkers in patients with deficit (n = 40) and non-deficit (n = 40) schizophrenia and healthy controls (n = 40). Deficit schizophrenia is characterized by significantly increased levels of AOPP and lowered -SH, and PON1 activity, while no changes in the OSTOX/ANTIOX biomarkers were found in non-deficit schizophrenia. An increased OSTOX/ANTIOX ratio was significantly associated with deficit versus non-deficit schizophrenia (odds ratio = 3.15, p < 0.001). Partial least squares analysis showed that 47.6% of the variance in a latent vector extracted from psychosis, excitation, hostility, mannerism, negative symptoms, psychomotor retardation, formal thought disorders, and neurocognitive test scores was explained by LOOH+AOPP, PON1 genotype + activity, CCL11, tumor necrosis factor (TNF)-α, and IgA responses to neurotoxic tryptophan catabolites (TRYCATs), whereas -SH groups and IgM responses to MDA showed indirect effects mediated by OSTOX and neuro-immune biomarkers. When overall severity of schizophrenia increases, multiple immune and oxidative (especially protein oxidation indicating chlorinative stress) neurotoxicities and impairments in immune-protective resilience become more prominent and shape a distinct nosological entity, namely deficit schizophrenia. The nomothetic network psychiatry approach allows building causal-pathway-phenotype models using machine learning techniques.

Transcriptomic abnormalities in peripheral blood in bipolar disorder, and discrimination of the major psychoses

We performed a transcriptome-wide meta-analysis and gene co-expression network analysis to identify genes and gene networks dysregulated in the peripheral blood of bipolar disorder (BD) cases relative to unaffected comparison subjects, and determined the specificity of the transcriptomic signatures of BD and schizophrenia (SZ). Nineteen genes and 4 gene modules were significantly differentially expressed in BD cases. Thirteen gene modules were shown to be differentially expressed in a combined case-group of BD and SZ subjects called "major psychosis", including genes biologically linked to apoptosis, reactive oxygen, chromatin remodeling, and immune signaling. No modules were differentially expressed between BD and SZ cases. Machine-learning classifiers trained to separate diagnostic classes based solely on gene expression profiles could distinguish BD cases from unaffected comparison subjects with an area under the curve (AUC) of 0.724, as well as BD cases from SZ cases with AUC = 0.677 in withheld test samples. We introduced a novel and straightforward method called "polytranscript risk scoring" that could distinguish BD cases from unaffected subjects (AUC = 0.672) and SZ cases (AUC = 0.607) significantly better than expected by chance. Taken together, our results highlighted gene expression alterations common to BD and SZ that involve biological processes of inflammation, oxidative stress, apoptosis, and chromatin regulation, and highlight disorder-specific changes in gene expression that discriminate the major psychoses.

Galantamine-Memantine Combination as an Antioxidant Treatment for Schizophrenia

PURPOSE OF REVIEW

The objective of this article is to highlight the potential role of the galantamine-memantine combination as a novel antioxidant treatment for schizophrenia.

RECENT FINDINGS

In addition to the well-known mechanisms of action of galantamine and memantine, these medications also have antioxidant activity. Furthermore, an interplay exists between oxidative stress, inflammation (redox-inflammatory hypothesis), and kynurenine pathway metabolites. Also, there is an interaction between brain-derived neurotrophic factor and oxidative stress in schizophrenia. Oxidative stress may be associated with positive, cognitive, and negative symptoms and impairments in white matter integrity in schizophrenia. The antipsychotic-galantamine-memantine combination may provide a novel strategy in schizophrenia to treat positive, cognitive, and negative symptoms.

SUMMARY

A "single antioxidant" may be inadequate to counteract the complex cascade of oxidative stress. The galantamine-memantine combination as "double antioxidants" is promising. Hence, randomized controlled trials are warranted with the antipsychotic-galantamine-memantine combination with oxidative stress and antioxidant biomarkers in schizophrenia.

Immunomodulatory effects of antipsychotic treatment on gene expression in first-episode psychosis

Previous studies suggest immunological alterations in patients with first-episode psychosis (FEP). Some studies show that antipsychotic compounds may cause immunomodulatory effects. To evaluate the immunological changes and the possible immunomodulatory effects in FEP, we recruited patients with FEP (n = 67) and matched controls (n = 38), aged 18-40 years, from the catchment area of the Helsinki University Hospital and the City of Helsinki, Finland. Fasting peripheral blood samples were collected between 8 and 10 a.m. in 10 ml PAXgene tubes. We applied the NanoString nCounter in-solution hybridization technology to determine gene expression levels of 147 candidate genes reflecting activation of the immune system. Cases had higher gene expression levels of BDKRB1 and SPP1/osteopontin compared with controls. Of the individual medications used as monotherapy, risperidone was associated with a statistically significant upregulation of 11 immune system genes, including cytokines and cytokine receptors (SPP1, IL1R1, IL1R2), pattern recognition molecules (TLR1, TLR2 and TLR6, dectin-1/CLEC7A), molecules involved in apoptosis (FAS), and some other molecules with functions in immune activation (BDKRB1, IGF1R, CR1). In conclusion, risperidone possessed strong immunomodulatory properties affecting mainly innate immune response in FEP patients, whereas the observed effects of quetiapine and olanzapine were only marginal. Our results further emphasize the importance of understanding the immunomodulatory mechanisms of antipsychotic treatment, especially in terms of specific compounds, doses and duration of medication in patients with severe mental illness. Future studies should evaluate the response pre- and post-treatment, and the possible role of this inflammatory activation for the progression of psychiatric and metabolic symptoms.

Profiling of Amino Acids and Their Derivatives Biogenic Amines Before and After Antipsychotic Treatment in First-Episode Psychosis

Schizophrenia (SCH) is a heterogeneous disorder, deriving from a potential multitude of etiopathogenetic factors. During the past few years there has been an increasing interest in the role of circulating amino acids (AAs) and biogenic amines (BAs) in the pathophysiology of SCH. In the present study, we aimed to provide an insight into the potential role of alterations in levels of AAs and BAs as well as examine their more specific metabolic shifts in relation to early stage of SCH. We measured 21 AAs and 17 BAs in serum samples of patients with first-episode psychosis (FEP) before and after 7-month antipsychotic treatment in comparison to control subjects (CSs). According to multivariate analysis, antipsychotic-naïve FEP patients had significantly higher levels of taurine and spermine, whereas values of proline (Pro), alpha-aminoadipic acid (alpha-AAA), kynurenine (Kyn), valine (Val), tyrosine (Tyr), citrulline (Citr), tryptophan (Trp), and histidine (His) were diminished compared to CSs. Increased levels of taurine and spermine, as well as reduced levels of alpha-AAA and Kyn probably reflect the compromised function of N-methyl-D-aspartate (NMDA) receptors in patients. The decreased levels of Pro (AA modulating the function of glutamate decarboxylase) likely reflect the imbalanced function of gamma-aminobutyric acid (GABA) system in the brain of FEP patients. The alterations in ratio between Tyr and phenylalanine (Phe) can be taken as a sign of compromised function of dopaminergic system. These metabolic shifts were reinstated by 7-month antipsychotic treatment. Serum metabolic profiles can be regarded as important indicators to investigate clinical course of SCH and treatment response.

Thiol/disulphide homeostasis in bipolar disorder

Bipolar disorder (BD) patients have increased oxidative stress, which can disturb thiol/disulphide homeostasis, causing disulphide formation. The aim of the study is to investigate dynamic thiol/disulphide (SH/SS) homeostasis in BD patients, which is a novel evaluation method of oxidative status. Ninety-four BD patients (50 in the manic episode and 44 in remission) and 44 healthy controls were included in the study. Blood serum native thiol (SH) and total thiol (ToSH) concentrations were measured in a paired test. The half value of the difference between native thiol and total thiol concentrations was calculated as the disulphide (SS) bond amount. Serum native thiol levels of the mania group were found to be lower than the remission and the control groups. There was a significant difference between the remission group and the control group in terms of native thiol. Serum total thiol level was lower in mania group than the control group. Detection of oxidative molecules for BD could be helpful, especially in treatment, follow-up periods and reducing morbidity. The results of our study besides the data available in the literature support that thiol and disulphide levels are useful markers for BD and promising therapeutic targets in terms of future pharmacological modulation.

ROS-Induced DNA Damage Associates with Abundance of Mitochondrial DNA in White Blood Cells of the Untreated Schizophrenic Patients

OBJECTIVE

The aim of this study was (1) to examine the leukocyte mtDNA copy number (CN) in unmedicated (SZ (m-)) and medicated (SZ (m+)) male patients with paranoid schizophrenia (SZ) in comparison with the healthy male controls (HC) and (2) to compare the leukocyte mtDNA CN with the content of an oxidation marker 8-oxodG in lymphocytes of the SZ (m-) patients.

METHODS

We evaluated leukocyte mtDNA CN of 110 subjects with SZ in comparison with 60 male HC by the method qPCR (ratio mtDNA/nDNA (gene B2M) was detected). SZ patients were divided into two subgroups. The patients of the subgroups SZ (m+) (N = 55) were treated with standard antipsychotic medications in the hospital. The patients of the subgroup SZ (m-) (N = 55) were not treated before venous blood was sampled. To evaluate oxidative DNA damage, we quantified the levels of 8-oxodG in lymphocytes (flow cytometry) of SZ (m-) patients (N = 55) and HC (N = 30).

RESULTS

The leukocyte mtDNA CN showed no significant difference in SZ (m+) patients and HC. The mtDNA CN in the unmedicated subgroup SZ (m-) was significantly higher than that in the SZ (m+) subgroup or in HC group. The level of 8-oxodG in the subgroup SZ (m-) was significantly higher than that in HC group.

CONCLUSION

The leukocytes of the unmedicated SZ male patients with acute psychosis contain more mtDNA than the leukocytes of the male SZ patients treated with antipsychotic medications or the healthy controls. MtDNA content positively correlates with the level of 8-oxodG in the unmedicated SZ patients.

Bridging Autism Spectrum Disorders and Schizophrenia through inflammation and biomarkers - pre-clinical and clinical investigations

In recent years, evidence supporting a link between inflammation and neuropsychiatric disorders has been mounting. Autism spectrum disorders (ASD) and schizophrenia share some clinical similarities which we hypothesize might reflect the same biological basis, namely, in terms of inflammation. However, the diagnosis of ASD and schizophrenia relies solely on clinical symptoms, and to date, there is no clinically useful biomarker to diagnose or monitor the course of such illnesses.

The focus of this review is the central role that inflammation plays in ASD and schizophrenia. It spans from pre-clinical animal models to clinical research and excludes in vitro studies. Four major areas are covered: (1) microglia, the inflammatory brain resident myeloid cells, (2) biomarkers, including circulating cytokines, oxidative stress markers, and microRNA players, known to influence cellular processes at brain and immune levels, (3) effect of anti-psychotics on biomarkers and other predictors of response, and (4) impact of gender on response to immune activation, biomarkers, and response to anti-psychotic treatments.

Profiling of Acylcarnitines in First Episode Psychosis before and after Antipsychotic Treatment

Acylcarnitines (ACs) have been shown to have a potential to activate pro-inflammatory signaling pathways and to foster the development of insulin resistance. The first task of the current study was to study the full list of ACs (from C2 to C18) in first episode psychosis (FEP) patients before and after antipsychotic treatment. The second task was to relate ACs to inflammatory and metabolic biomarkers established in the same patient cohort as in our previous studies. Serum levels of ACs were determined with the AbsoluteIDQ p180 kit (BIOCRATES Life Sciences AG, Innsbruck, Austria) using the flow injection analysis tandem mass spectrometry ([FIA]-MS/MS) as well as liquid chromatography ([LC]-MS/MS) technique. Identification and quantification of the metabolites was achieved using multiple reactions monitoring along with internal standards. The comparison of ACs in antipsychotic-naïve first-episode psychosis (FEP) patients (N = 38) and control subjects (CSs, N = 37) revealed significantly increased levels of long-chain ACs (LCACs) C14:1 (p = 0.0001), C16 (p = 0.00002), and C18:1 (p = 0.000001) in the patient group. These changes of LCACs were associated with augmented levels of CARN palmitoyltransferase 1 (CPT-1) (p = 0.006). By contrast, the level of short-chain AC (SCAC) C3 was significantly reduced (p = 0.00003) in FEP patients. Seven months of antipsychotic drug treatment ameliorated clinical symptoms in patients (N = 36) but increased significantly their body mass index (BMI, p = 0.001). These changes were accompanied by significantly reduced levels of C18:1 (p = 0.00003) and C18:2 (p = 0.0008) as well as increased level of C3 (p = 0.01). General linear model revealed the relation of LCACs (C16, C16:1, and C18:1) to the inflammatory markers (epidermal growth factor, IL-2, IL-4, IL-6), whereas SCAC C3 was linked to the metabolic markers (leptin, C-peptide) and BMI. FEP was associated with an imbalance of ACs in patients because the levels of several LCACs were significantly higher and the levels of several SCACs were significantly reduced compared with CSs. This imbalance was modified by 7 months of antipsychotic drug treatment, reversing the levels of both LCACs and SCACs to that established for CSs. This study supports the view that ACs have an impact on both inflammatory and metabolic alterations inherent for FEP.

Oxidative and nitrosative stress biomarkers in chronic schizophrenia

There is evidence that the acute phase of schizophrenia (SCZ) is accompanied by specific changes in oxidative and nitrosative stress (O&NS) biomarkers. There are, however, no firm data regarding these biomarkers in chronic SCZ. Therefore, this study aimed to delineate O&NS biomarkers in patients with chronic SCZ. 125 outpatients with SCZ and 118 controls were enrolled. The markers included lipid hydroperoxides (LOOH), advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), total radical-trapping antioxidant parameter (TRAP) and paraoxonase 1 (PON-1) activity. Immune-inflammatory markers known to be altered in SCZ were also measured: leptin, IL-6, soluble TNF receptors (sTNF-Rs) and the chemokines CCL-11 and CCL-3. There were no significant associations between chronic SCZ and the O&NS markers (AOPP, NOx, LOOH) and the anti-oxidants PON-1 and TRAP. Leptin, sTNF-R, CCL-3 and CCL-11 were significantly higher in SCZ. There were significant associations between pro-inflammatory and O&NS biomarkers (leptin/CCL-8 and AOPP; IL-6 and NOx; CCL-3 and LOOH; CCL-3/IL-6/NOx and TRAP). In conclusion, there were significant intercorrelations between inflammatory and O&NS pathways, which play a role in the pathophysiology of chronic SCZ. O&NS markers and the enzyme PON-1 are not useful as biomarkers in chronic stable polymedicated SCZ patients.

Oxidative Stress and Inflammation in Early Onset First Episode Psychosis: A Systematic Review and Meta-Analysis

Background

People with schizophrenia and other psychosis show increased proinflammatory and prooxidative status. However, the few studies that have specifically assessed oxidative and inflammatory markers in early onset psychosis (onset before age 18) have shown contradictory results.

Methods

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines for systematic reviews and meta-analyses were used to conduct a systematic literature search to detect studies comparing inflammatory and oxidative markers in early onset psychosis patients and healthy controls.

Results

Seven studies met criteria for the qualitative analysis. Four studies met criteria for meta-analysis, comprising an overall sample of 261 early onset psychosis patients and 246 healthy controls. Six independent meta-analyses were performed for catalase, glutathione, glutathione peroxidase, superoxide dismutase, total antioxidant status, and cell/DNA oxidative damage. No significant differences were found between early onset psychosis patients and controls in any of the parameters assessed. Heterogeneity among studies was high. Qualitative analysis of individual studies showed an association of inflammatory and oxidative markers with clinical, cognitive, and neurobiological outcomes, especially in longitudinal assessments.

Conclusions

Despite the lack of significant differences between early onset psychosis patients and controls in the oxidative markers assessed in the meta-analyses, results based on individual studies suggest that greater inflammation and oxidative stress might lead to poorer outcomes in patients with first episodes of early onset psychosis.

Mechanism of synergistic action on behavior, oxidative stress and inflammation following co-treatment with ketamine and different antidepressant classes

BACKGROUND

Major depressive disorder (MDD) affects many people in the world. However, around 40% of patients do not respond to any pharmacological drugs. An alternative is to use a combination of different pharmacological groups or the combination of a classical antidepressant with a substance that can potentiate its effect. Thus, this study aimed to investigate the synergistic interactions between different antidepressants, including fluoxetine, quetiapine and lamotrigine in combination with ketamine, a N-methyl-d-aspartate (NMDA) receptor antagonist.

METHODS

Wistar rats were acutely treated with fluoxetine (1.25mg/kg), quetiapine (5mg/kg), and lamotrigine (5.0mg/kg) alone or in combination with ketamine (5.0mg/kg), and then subjected to behavioral tests. In addition, oxidative damage and antioxidant capacity were assessed in the rat brain, and pro-inflammatory cytokines levels were evaluated in the serum.

RESULTS

It was observed a synergistic effect of ketamine in combination with fluoxetine on the immobility time in the forced swimming test, indicating an antidepressant effect. Other antidepressant did not show effects when administrated alone or joint to ketamine. The combination of ketamine with other antidepressants, particularly quetiapine, in some brain regions induced an increase in damage to lipids and proteins. However, the combination of ketamine with fluoxetine increased the antioxidant activity of superoxide dismutase, and decreased oxidative damage, thus suggesting a neuroprotective effect of the combination of these drugs. The combination of ketamine with fluoxetine or lamotrigine reduced pro-inflammatory cytokines levels.

CONCLUSION

In conclusion, ketamine induced antioxidant or pro-antioxidant effects dependent of antidepressant classes or brain area.