A pilot study of cortical glutathione in youth with depression

Glutathione in HIV-Associated Neurocognitive Disorders

A large portion of patients with Human Immunodeficiency Virus (HIV) have neurologic sequelae. Those with better-controlled HIV via antiretroviral therapies generally have less severe neurologic symptoms. However, for many patients, antiretrovirals do not adequately resolve symptoms. Since much of the pathogenesis of HIV/AIDS (Autoimmune Deficiency Syndrome) involves oxidative stress either directly, through viral interaction, or indirectly, through inflammatory mechanisms, we have reviewed relevant trials of glutathione supplementation in each of the HIV-associated neurocognitive diseases and have found disease-specific results. For diseases for which trials have not been completed, predicted responses to glutathione supplementation are made based on relevant mechanisms seen in the literature. It is not sufficient to conclude that all HIV-associated neurocognitive disorders (HAND) will benefit from the antioxidant effects of glutathione supplementation. The potential effects of glutathione supplementation in patients with HAND are likely to differ based on the specific HIV-associated neurocognitive disease.

Efficacy of addition of the anti-inflammatory, IV glutathione to standard ketamine IV therapy in major depressive disorder

Ketamine, a N-methyl-D-aspartate (NMDA) antagonist, is used for treatment-resistant depression (TRD). Recent studies have shown that there are increased levels of pro-inflammatory cytokines in individuals with major depressive disorder (MDD) and those with higher levels of oxidative stress markers have a decreased or null response to conventional antidepressants. Glutathione (GSH) as an antioxidant adjuvant to ketamine has not been well studied. This double-blind study with 30 patients divided into 2 groups of 15 each, aimed to determine if GSH, added to standard ketamine infusion (GSH+K), rendered better outcomes in MDD patients versus patients receiving ketamine infusions with a normal saline placebo (K+NS). There were significant drops in BDI-II scores from day 1 to day 14, PHQ- scores from day 1 to day 14 and PHQ-9 scores day 14 to day 28, suggesting the overall treatment was effective. There were no statistically significant differences between the groups over time. However, a sustained improvement in depressive symptoms was observed for 14 days post-infusion in both groups.

Sildenafil, alone and in combination with imipramine or escitalopram, display antidepressant-like effects in an adrenocorticotropic hormone-induced (ACTH) rodent model of treatment-resistant depression

BACKGROUND

Major depressive disorder (MDD) represents a challenge with high prevalence and limited effectiveness of existing treatments, particularly in cases of treatment-resistant depression (TRD). Innovative strategies and alternative drug targets are therefore necessary. Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is known to exert neuroplastic, anti-inflammatory, and antioxidant properties, and is a promising antidepressant drug candidate.

AIM

To investigate whether sildenafil monotherapy or in combination with a known antidepressant, can elicit antidepressant-like effects in an adrenocorticotropic hormone (ACTH)-induced rodent model of TRD.

METHODS

ACTH-naïve and ACTH-treated male Sprague-Dawley (SD) rats received various sub-acute drug treatments, followed by behavioural tests and biochemical analyses conversant with antidepressant actions.

RESULTS

Sub-chronic ACTH treatment induced significant depressive-like behaviour in rats, evidenced by increased immobility during the forced swim test (FST). Sub-acute sildenafil (10 mg/kg) (SIL-10) (but not SIL-3), and combinations of imipramine (15 mg/kg) (IMI-15) and sildenafil (3 mg/kg) (SIL-3) or escitalopram (15 mg/kg) (ESC-15) and SIL-3, exhibited significant antidepressant-like effects. ACTH treatment significantly elevated hippocampal levels of brain-derived neurotrophic factor (BDNF), serotonin, norepinephrine, kynurenic acid (KYNUA), quinolinic acid (QUINA), and glutathione. The various mono- and combined treatments significantly reversed some of these changes, whereas IMI-15 + SIL-10 significantly increased glutathione disulfide levels. ESC-15 + SIL-3 significantly reduced plasma corticosterone levels.

CONCLUSION

This study suggests that sildenafil shows promise as a treatment for TRD, either as a stand-alone therapy or in combination with a traditional antidepressant. The neurobiological mechanism underlying the antidepressant-like effects of the different sildenafil mono- and combination therapies reflects a multimodal action and cannot be explained in full by changes in the individually measured biomarker levels.

Specific inhibitor of Wnt/beta-catenin pathway can alter behavioral responses in young rats with malformed cortices

The Wnt/beta-catenin pathway plays a crucial role in regulating cellular processes and has been implicated in neural activity-dependent learning as well as anxiety. However, the role of this pathway in young children with abnormal cortical development is unknown. Cortical malformations at early development, behavioral abnormalities, and a susceptibility to seizures have been reported in rats prenatally exposed to methylazoxymethanol. In this study, we aimed to investigate whether we could improve the behavioral deficits in young rats with malformed cerebral cortices by modulation of the Wnt/beta-catenin pathway. We found a small molecule Wnt/beta-catenin inhibitor (CWP) that increased exploratory behavior in the open field test (P9, CWP 100 ug treatment, peripheral exploration, P = 0.011) and social behavior test (P12, CWP 250 ug treatment, distance traveled in center, P = 0.033) and decreased anxiety in fear conditioning. However, it did not reduce the susceptibility to seizures. After high dose (250 ug) CWP treatment at P12, phosphocreatine and glutathione (GSH) were decreased in the cortex at P15 (P = 0.021). These findings suggest that the role of Wnt/beta-catenin signaling in exploratory behavior and anxiety during early development warrants further investigation.

Overview of metabolomic aspects in postpartum depression

Along with the typical biochemical alterations that occur during pregnancy, certain metabolic changes might be associated with the development of several psychiatric disorders, including postpartum depression (PPD), which is the most common type of psychiatric disorder during pregnancy or first postpartum year, and it develops in about 15% of women. Metabolomics is a rapidly developing discipline that deals with the metabolites as the final products of all genetically controlled biochemical pathways, highly influenced by external and internal changes. The aim of this paper was to review the published studies whose results suggest or deny a possible association between the fine regulation of the metabolome and PPD, enabling conclusions about whether metabolomics could be a useful tool in defining the biochemical pathways directly involved in the etiology, diagnosis and course of PPD. Beside numerous hormonal changes, a lot of different metabolic pathways have been discovered to be affected in women with PPD or associated with its development, including alterations in the energy metabolism, tryptophan and amino acid metabolism, steroid metabolism, purine cycle, as well as neurotransmitter metabolism. Additionally, metabolomics helped in defining the association between PPD and the exposure to various endocrine disrupting metabolites during pregnancy. Finally, metabolome reflects different PPD therapies and exposure of fetus or breastfed infants to pharmacotherapy prescribed to a mother suffering from PPD. This review can help in creating the picture about metabolomics' broad application in PPD studies, but it also implies that its potential is still not completely used.

Prefrontal Glutathione Levels in Major Depressive Disorder Are Linked to a Lack of Positive Affect

Major depressive disorder (MDD) is one of the most common neuropsychiatric disorders, with symptoms including persistent sadness and loss of interest. MDD is associated with neurochemical alterations in GABA, glutamate, and glutamine levels but, to date, few studies have examined changes in glutathione (GSH) in MDD. This study investigated changes in GSH in an unmedicated group of young adults, including 46 participants with current (n = 12) or past MDD (n = 34) and 20 healthy controls. Glutathione levels were assessed from GSH-edited magnetic resonance (MR) spectra, acquired from a voxel in the left prefrontal cortex, and depressive symptoms were evaluated with validated questionnaires and clinical assessments. Cortisol levels were also assessed as a marker for acute stress. Participants with current MDD demonstrated elevated GSH in comparison to participants with past MDD and controls, although the results could be influenced by differences in tissue composition within the MRS voxel. In addition, participants with both current and past MDD showed elevated cortisol levels in comparison to controls. No significant association was observed between GSH and cortisol levels, but elevated GSH levels were associated with a decrease in positive affect. These results demonstrate for the first time that elevated GSH in current but not past depression may reflect a state rather than a trait neurobiological change, related to a loss of positive affect.

A Comprehensive Overview of the Role of Visual Cortex Malfunction in Depressive Disorders: Opportunities and Challenges

Major depressive disorder (MDD) is a highly heterogeneous mental disorder, and its complex etiology and unclear mechanism are great obstacles to the diagnosis and treatment of the disease. Studies have shown that abnormal functions of the visual cortex have been reported in MDD patients, and the actions of several antidepressants coincide with improvements in the structure and synaptic functions of the visual cortex. In this review, we critically evaluate current evidence showing the involvement of the malfunctioning visual cortex in the pathophysiology and therapeutic process of depression. In addition, we discuss the molecular mechanisms of visual cortex dysfunction that may underlie the pathogenesis of MDD. Although the precise roles of visual cortex abnormalities in MDD remain uncertain, this undervalued brain region may become a novel area for the treatment of depressed patients.

Anti-Inflammatory, Antioxidant, and Neuroprotective Effects of Polyphenols-Polyphenols as an Element of Diet Therapy in Depressive Disorders

Depressive disorders can affect up to 350 million people worldwide, and in developed countries, the percentage of patients with depressive disorders may be as high as 10%. During depression, activation of pro-inflammatory pathways, mitochondrial dysfunction, increased markers of oxidative stress, and a reduction in the antioxidant effectiveness of the body are observed. It is estimated that approximately 30% of depressed patients do not respond to traditional pharmacological treatments. However, more and more attention is being paid to the influence of active ingredients in food on the course and risk of neurological disorders, including depression. The possibility of using foods containing polyphenols as an element of diet therapy in depression was analyzed in the review. The possibility of whether the consumption of products such as polyphenols could alleviate the course of depression or prevent the progression of it was also considered. Results from preclinical studies demonstrate the potential of phenolic compounds have the potential to reduce depressive behaviors by regulating factors related to oxidative stress, neuroinflammation, and modulation of the intestinal microbiota.

Can glutathione be a biomarker for suicide risk in women 18 months postpartum?

BACKGROUND

Suicide risk is prominent among the problems affecting populations, mainly due to the broad family, psychosocial and economic impact. Most individuals at suicidal risk have some mental disorder. There is considerable evidence that psychiatric disorders are accompanied by the activation of neuro-immune and neuro-oxidative pathways. The aim of the study is to evaluate the serum levels of oxidative stress biomarkers in women at risk of suicide after 18 months of postpartum.

METHODS

This is a case-control study, nested within a cohort study. From this cohort, 45 women [15 without mood disorders and 30 with mood disorders (Major depression and Bipolar disorder)] were selected at 18 months postpartum, the depression and suicide risk were assessed using the Mini-International Neuropsychiatric Interview Plus (MINI-Plus) instrument, module A and C, respectively. Blood was collected and stored for later analysis of the reactive species (DCFH), superoxide dismutase (SOD), and glutathione reduced (GSH). For data analysis, the SPSS program was used. To compare the nominal covariates with the outcome GSH levels, the Student's t-test or analysis of variance (ANOVA) was used. Spearman's correlation was performed for analysis between the quantitative covariates and the outcome. To analyze the interaction between the factors, multiple linear regression was performed. Bonferroni analysis was used as an additional/secondary result to visualize differences in glutathione levels according to risk severity. After the adjusted analysis, p-values < 0.05 were considered statistically significant.

RESULTS

The percentage of suicide risk observed in our sample of women at 18 months postpartum was 24.4% (n = 11). After adjusting for the independent variables, only the presence of suicide risk remained associated with the outcome (β = 0.173; p = 0.007), low levels of GSH at 18 months after postpartum. Likewise, we verified the difference in GSH levels according to the degree of suicide risk, observing a significant association between the differences in glutathione means in the group of women with moderate to high risk compared to the reference group (no suicide risk) (p = 0.009).

CONCLUSION

Our findings suggest that GSH may be a potential biomarker or etiologic factor in women at moderate to high risk of suicide.

Childhood depression and oxidative stress

Background

Oxidative stress is a contributing factor in the etiopathogenesis of major depressive disorder (MDD). Pediatric studies regarding MDD-oxidative stress relationship are insufficient. In this study, we aimed to compare oxidative stress parameters of pediatric MDD patients with those of the control group and to examine factors affecting these parameters.

Results

Total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), malondialdehyde (MDA) and superoxide dismutase (SOD) activities of 42 patients with MDD and 38 healthy controls were evaluated. Children depression inventory (CDI) was applied to all participants. In the MDD group, serum levels of TOS, OSI and MDA were higher, while TAS and SOD levels were lower (p < 0.001). When all participants were examined, oxidative stress increased as the CDI score increased, but in the MDD group, SOD increased as the CDI score increased. Increase in body mass index (BMI) percentile increased the oxidative stress in the MDD group. When factors affecting the presence of MDD were analyzed by binary logistic regression analysis, a one-unit increase in SOD decreased depression by 0.190 times.

Conclusions

This study showed that oxidative stress increases in children and adolescents with MDD, and the increase in the severity of depression further increases oxidative stress, but when the depression becomes very severe, level of SOD increases compensatorily. It has been observed that high BMI in MDD patients creates an additional burden on oxidative stress. The role of oxidative stress in the etiopathogenesis of MDD in children and adolescents should be evaluated more comprehensively.

Schizophrenia, Bipolar and Major Depressive Disorders: Overview of Clinical Features, Neurotransmitter Alterations, Pharmacological Interventions, and Impact of Oxidative Stress in the Disease Process

Psychiatric disorders are one of the leading causes of disability worldwide and affect the quality of life of both individuals and the society. The current understanding of these disorders points toward receptor dysfunction and neurotransmitter imbalances in the brain. Treatment protocols are hence oriented toward normalizing these imbalances and ameliorating the symptoms. However, recent literature has indicated the possible role of depleted levels of antioxidants like glutathione (GSH) as well as an alteration in the levels of the pro-oxidant, iron in the pathogenesis of major psychiatric diseases, viz., schizophrenia (Sz), bipolar disorder (BD), and major depressive disorder (MDD). This review aims to highlight the involvement of oxidative stress (OS) in these psychiatric disorders. An overview of the clinical features, neurotransmitter abnormalities, and pharmacological treatments concerning these psychiatric disorders has also been presented. Furthermore, it attempts to synthesize literature from existing magnetic resonance spectroscopy (MRS) and quantitative susceptibility mapping (QSM) studies for these disorders, assessing GSH and iron, respectively. This manuscript is a sincere attempt to stimulate research discussion to advance the knowledge base for further understanding of the pathoetiology of Sz, BD, and MDD.

Association Between Socio-Affective Symptoms and Glutathione and CD4 and CD8 Lymphocytes in College Students

Background: The prevalence of anxiety and depression in young students is associated with biosocial factors and scholastic stress. However, few studies have evaluated emotional-affective symptoms that are related to the immune system and antioxidant parameters in young individuals without diagnoses of affective disorders. Aim: This study aims to assess the relationship between emotional-affective symptoms and glutathione concentrations and CD4 and CD8 lymphocyte counts in college students. Methods: College students (n = 177) completed standardized psychometric instruments, including the Perceived Stress Scale, Hamilton Anxiety Scale, Beck Depression Inventory, Familiar Social and Friends Support Scale, and Rosenberg Scale. Blood samples were biochemically analyzed. Analyses of variance were conducted between four groups according to symptom severity. Results: A considerable prevalence of stress, anxiety, and depression symptoms was observed and negatively correlated with self-esteem and socio-familiar support. Perceived stress was sexually dimorphic. Although biochemical parameters were within reference ranges, glutathione, CD4, and CD8 tended to be lower in participants with anxiety and depression symptoms, which may be of predictive value. Conclusion: The relationship between antioxidant/immune parameters and socio-affective scores is latent in undiagnosed college students who might develop affective disorders. The findings suggest that during the initial development of affective disorders, stress management strategies should be implemented to help college students cope with the academic load and monitor negative changes in their physiological state.

Importance of oxidative stress in the pathogenesis, diagnosis, and monitoring of patients with neuropsychiatric disorders, a review

Oxidative stress is defined as the persistent imbalance between the activity of toxic reactive forms of both oxygen and nitrogen and the antioxidant defense. In low concentrations, they are essential for the proper functioning of the body. Still, their excessive amount contributes to the damage of the biomolecules, consequently leading to various pathologies of the organism. Due to the lipid-rich brain structure, enormous oxygen consumption, and the lack of a sufficient antioxidant barrier make it highly susceptible to oxidative imbalance. Hence, oxidative stress has been linked to various psychiatric disorders. These diseases include all behavioral, emotional, and cognitive abnormalities associated with a significant impediment to social life. Each of the diseases in question: Alzheimer's disease, schizophrenia, depression, and bipolar disorder, is characterized by excessive oxidative stress. Considerable damages to DNA, RNA, proteins, lipids, and mitochondrial dysfunction, are observed. All conditions show increased lipid peroxidation, which appears to be typical of psychiatric disorders because the brain contains large amounts of these types of molecules. In addition, numerous abnormalities in the antioxidant defense are noted, but the results of studies on the activity of antioxidant enzymes differ significantly. The most promising biomarkers seem to be GSH in Alzheimer's disease as an early-stage marker of the disease and thioredoxin in schizophrenia as a marker for therapy monitoring. Data from the literature are consistent with the decrease in antioxidants such as vitamin C, E, uric acid, albumin, etc. Despite these numerous inconsistencies, it seems that oxidative stress is present in the course of psychiatric diseases. Still, it cannot be conclusively determined whether it is the direct cause of development, a consequence of other abnormalities at the biochemical or molecular level, or the result of the disease itself.

Is There a Glutathione Centered Redox Dysregulation Subtype of Schizophrenia?

Schizophrenia continues to be an illness with poor outcome. Most mechanistic changes occur many years before the first episode of schizophrenia; these are not reversible after the illness onset. A developmental mechanism that is still modifiable in adult life may center on intracortical glutathione (GSH). A large body of pre-clinical data has suggested the possibility of notable GSH-deficit in a subgroup of patients with schizophrenia. Nevertheless, studies of intracortical GSH are not conclusive in this regard. In this review, we highlight the recent ultra-high field magnetic resonance spectroscopic studies linking GSH to critical outcome measures across various stages of schizophrenia. We discuss the methodological steps required to conclusively establish or refute the persistence of GSH-deficit subtype and clarify the role of the central antioxidant system in disrupting the brain structure and connectivity in the early stages of schizophrenia. We propose in-vivo GSH quantification for patient selection in forthcoming antioxidant trials in psychosis. This review offers directions for a promising non-dopaminergic early intervention approach in schizophrenia.

Oxidative Stress Markers and Antioxidant Enzymes in Children and Adolescents with Depressive Disorder and Impact of Omega-3 Fatty Acids in Randomised Clinical Trial

Oxidative stress (OS) is thought to play a role in mental disorders. However, it is not clear whether the OS is the cause or consequence of the disorder. We investigated markers of oxidative stress (8-isoprostane (8-IsoP-U), lipoperoxides (LP), advanced oxidation protein products (AOPP) and nitrotyrosine (NT)) and antioxidant protection (Trolox equivalent antioxidant capacity (TEAC), activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) in 60 paediatric and adolescent patients with depressive disorder (DD) compared to healthy controls. The patients were divided into two groups (1:1). One group received an emulsion of omega-3 fatty acid (FA), and the other group an emulsion of sunflower oil with omega-6 FA for 12 weeks. The levels of 8-IsoP-U, AOPP and NT were increased, and GPx activity was decreased in patients compared to the controls. We found a significant positive correlation of the Children’s Depression Inventory score with NT and a negative correlation with TEAC, SOD and GPx. NT correlated positively with the baseline omega-6/omega-3 FA ratio and a negatively with SOD. A supplementation with omega-3 FA, but not with omega-6 FA, decreased 8-IsoP-U, AOPP, NT levels and increased TEAC and SOD activity. Our results suggest that NT may play a role in the pathophysiology of DD, while elevated isoprostane is likely caused by the high omega-6/omega-3 FA ratio. Omega-3 FA supplementation reduces oxidative stress in patients with DD. This study was registered with the ISRCTN registry (ISRCTN81655012).

Multimodal Investigations of Reward Circuitry and Anhedonia in Adolescent Depression

Depression is a highly prevalent condition with devastating personal and public health consequences that often first manifests during adolescence. Though extensively studied, the pathogenesis of depression remains poorly understood, and efforts to stratify risks and identify optimal interventions have proceeded slowly. A major impediment has been the reliance on an all-or-nothing categorical diagnostic scheme based solely on whether a patient endorses an arbitrary number of common symptoms for a sufficiently long period. This approach masks the well-documented heterogeneity of depression, a disorder that is highly variable in presentation, severity, and course between individuals and is frequently comorbid with other psychiatric conditions. In this targeted review, we outline the limitations of traditional diagnosis-based research and instead advocate an alternative approach centered around symptoms as unique dimensions of clinical dysfunction that span across disorders and more closely reflect underlying neurobiological abnormalities. In particular, we highlight anhedonia-the reduced ability to anticipate and experience pleasure-as a specific, quantifiable index of reward dysfunction and an ideal candidate for dimensional investigation. Anhedonia is a core symptom of depression but also a salient feature of numerous other conditions, and its severity varies widely within clinical and even healthy populations. Similarly, reward dysfunction is a hallmark of depression but is evident across many psychiatric conditions. Reward function is especially relevant in adolescence, a period characterized by exaggerated reward-seeking behaviors and rapid maturation of neural reward circuitry. We detail extensive work by our research group and others to investigate the neural and systemic factors contributing to reward dysfunction in youth, including our cumulative findings using multiple neuroimaging and immunological measures to study depressed adolescents but also trans-diagnostic cohorts with diverse psychiatric symptoms. We describe convergent evidence that reward dysfunction: (a) predicts worse clinical outcomes, (b) is associated with functional and chemical abnormalities within and beyond the neural reward circuitry, (c) is linked to elevated peripheral levels of inflammatory biomarkers, and (d) manifests early in the course of illness. Emphasis is placed on high-resolution neuroimaging techniques, comprehensive immunological assays, and data-driven analyses to fully capture and characterize the complex, interconnected nature of these systems and their contributions to adolescent reward dysfunction.

Phloridzin ameliorates type 2 diabetes-induced depression in mice by mitigating oxidative stress and modulating brain-derived neurotrophic factor

PURPOSE

Type 2 diabetes (T2D) is linked with depression due to insulin resistance, oxidative stress and disruption of neurotrophic factors. We evaluated potential benefits of phloridzin in ameliorating depressive symptoms in T2D.

METHODS

Adult male Swiss-albino mice (25-30 g) on high-fat-diet (HFD) for 2 weeks were administered with streptozotocin (STZ; 35 mg/kg, intraperitoneal) to induce T2D. Seven days after STZ administration, diabetic mice on HFD were distributed into different groups. Animals were subjected daily to oral treatment of saline (0.25 ml), fluoxetine (10-20 mg/kg) or phloridzin (10-20 mg/kg) for a period of 4 weeks. One hour after last dose, the immobility time of animals was evaluated in forced swim test (FST) and tail suspension test (TST). To further confirm the mechanisms involved in antidepressant effect of phloridzin, biochemical parameters like brain derived neurotropic factor (BDNF), glutathione (GSH), extracellular signal-regulated kinase (ERK), tyrosine receptor kinase B (TrkB) and cAMP-response element binding protein (CREB) were estimated in the brain.

RESULTS

Animals with T2D showed a significant increase in immobility as compared to control in FST and TST. However, 4 weeks administration of fluoxetine or phloridzin attenuated this effect. A significant decline in GSH, BDNF, TrkB, CREB and ERK levels were noticed in the brain of mice with T2D. These changes were also attenuated by administration of phloridzin.

CONCLUSIONS

Phloridzin may ameliorates T2D-induced depression by mitigating the oxidative stress, and up-regulation of neurotrophins in the brain. Therefore, phloridzin can be used as a therapeutic intervention for the management of depression co-morbid with T2D.

Immunological Disturbances and Neuroimaging Findings in Major Depressive Disorder (MDD) and Alcohol Use Disorder (AUD) Comorbid Patients

Mood disorders and Major Depressive Disorder, in particular, appear to be some of the most common psychiatric disorders with a high rate of comorbidity most frequently of anxiety or substance abuse disorders (alcohol use disorder). In both cases - MDD and AUD, a number of immunological disturbances are observed, such as chronic mild inflammation response, increased level of cytokines, hypercortisolaemia, which lead to specific changes in brain neurotransmitter functions. Some of the contemporary brain imaging techniques are functional magnetic resonance imaging (fMRI) and magnetic spectroscopy which are most commonly used to assess the brain metabolism and functional connectivity changes such as altered responses to emotional stimuli in MDD or overactivation of ventromedial prefrontal areas during delayed and underactivation of dorsolateral prefrontal regions during impulsive reward decisions in AUD and dysfunction of gamma-aminobutyric acid (GABA) and/or glutamate neurotransmitter systems, low NAA and myo-Inositol in both MDD and AUD.

Increasing Nrf2 Activity as a Treatment Approach in Neuropsychiatry

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor encoded by NFE2L2. Under oxidative stress, Nrf2 does not undergo its normal cytoplasmic degradation but instead travels to the nucleus, where it binds to a DNA promoter and initiates transcription of anti-oxidative genes. Nrf2 upregulation is associated with increased cellular levels of glutathione disulfide, glutathione peroxidase, glutathione transferases, thioredoxin and thioredoxin reductase. Given its key role in governing the cellular antioxidant response, upregulation of Nrf2 has been suggested as a common therapeutic target in neuropsychiatric illnesses such as major depressive disorder, bipolar disorder and schizophrenia, which are associated with chronic oxidative and nitrosative stress, characterised by elevated levels of reactive oxygen species, nitric oxide and peroxynitrite. These processes lead to extensive lipid peroxidation, protein oxidation and carbonylation, and oxidative damage to nuclear and mitochondrial DNA. Intake of N-acetylcysteine, coenzyme Q₁₀ and melatonin is accompanied by increased Nrf2 activity. N-acetylcysteine intake is associated with improved cerebral mitochondrial function, decreased central oxidative and nitrosative stress, reduced neuroinflammation, alleviation of endoplasmic reticular stress and suppression of the unfolded protein response. Coenzyme Q₁₀, which acts as a superoxide scavenger in neuroglial mitochondria, instigates mitohormesis, ameliorates lipid peroxidation in the inner mitochondrial membrane, activates uncoupling proteins, promotes mitochondrial biogenesis and has positive effects on the plasma membrane redox system. Melatonin, which scavenges mitochondrial free radicals, inhibits mitochondrial nitric oxide synthase, restores mitochondrial calcium homeostasis, deacetylates and activates mitochondrial SIRT3, ameliorates increased permeability of the blood-brain barrier and intestine and counters neuroinflammation and glutamate excitotoxicity.

The interplay between oxidative stress and bioenergetic failure in neuropsychiatric illnesses: can we explain it and can we treat it?

Nitro-oxidative stress and lowered antioxidant defences play a key role in neuropsychiatric disorders such as major depression, bipolar disorder and schizophrenia. The first part of this paper details mitochondrial antioxidant mechanisms and their importance in reactive oxygen species (ROS) detoxification, including details of NO networks, the roles of H₂O₂ and the thioredoxin/peroxiredoxin system, and the relationship between mitochondrial respiration and NADPH production. The second part highlights and identifies the causes of the multiple pathological sequelae arising from self-amplifying increases in mitochondrial ROS production and bioenergetic failure. Particular attention is paid to NAD⁺ depletion as a core cause of pathology; detrimental effects of raised ROS and reactive nitrogen species on ATP and NADPH generation; detrimental effects of oxidative and nitrosative stress on the glutathione and thioredoxin systems; and the NAD⁺-induced signalling cascade, including the roles of SIRT1, SIRT3, PGC-1α, the FOXO family of transcription factors, Nrf1 and Nrf2. The third part discusses proposed therapeutic interventions aimed at mitigating such pathology, including the use of the NAD⁺ precursors nicotinamide mononucleotide and nicotinamide riboside, both of which rapidly elevate levels of NAD⁺ in the brain and periphery following oral administration; coenzyme Q₁₀ which, when given with the aim of improving mitochondrial function and reducing nitro-oxidative stress in the brain, may be administered via the use of mitoquinone, which is in essence ubiquinone with an attached triphenylphosphonium cation; and N-acetylcysteine, which is associated with improved mitochondrial function in the brain and produces significant decreases in oxidative and nitrosative stress in a dose-dependent manner.

Effect of Age on GABA+ and Glutathione in a Pediatric Sample

BACKGROUND AND PURPOSE

Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the human brain and is implicated in several neuropathologies. Glutathione is a major antioxidant in the brain and is considered a marker of oxidative stress. Several studies have reported age-related declines in GABA levels in adulthood, but the trajectory of both GABA and glutathione during childhood has not been well explored. The aim of this study is to establish how GABA and glutathione vary with age during early development.

MATERIALS AND METHODS

Twenty-three healthy children (5.6-13.9 years of age) were recruited for this study. MR imaging/MR spectroscopy experiments were conducted on a 3T MR scanner. A 27-mL MR spectroscopy voxel was positioned in the frontal lobe. J-difference edited MR spectroscopy was used to spectrally edit GABA and glutathione. Data were analyzed using the Gannet software, and GABA+ (GABA + macromolecules/homocarnosine) and glutathione were quantified using water (GABA+_H2O and Glutathione_H2O) and Cr (GABA+/Cr and glutathione/Cr) as concentration references. Also, the relative gray matter contribution to the voxel volume (GM_ratio) was estimated from structural images. Pearson correlation coefficients were used to examine the association between age and GABA+_H2O (and glutathione_H2O), between age and GABA+/Cr (and glutathione/Cr), and between age and GM_ratio.

RESULTS

Both GABA+_H2O (r = 0.63, P = .002) and GABA+/Cr (r = 0.48, P = .026) significantly correlated with age, whereas glutathione measurements and GM_ratio did not.

CONCLUSIONS

We demonstrate increases in GABA and no differences in glutathione with age in a healthy pediatric sample. This study provides insight into neuronal maturation in children and may facilitate better understanding of normative behavioral development and the pathophysiology of developmental disorders.

Targeting Inflammatory-Mitochondrial Response in Major Depression: Current Evidence and Further Challenges

The prevalence of psychiatric disorders has increased in recent years. Among existing mental disorders, major depressive disorder (MDD) has emerged as one of the leading causes of disability worldwide, affecting individuals throughout their lives. Currently, MDD affects 15% of adults in the Americas. Over the past 50 years, pharmacotherapy, psychotherapy, and brain stimulation have been used to treat MDD. The most common approach is still pharmacotherapy; however, studies show that about 40% of patients are refractory to existing treatments. Although the monoamine hypothesis has been widely accepted as a molecular mechanism to explain the etiology of depression, its relationship with other biochemical phenomena remains only partially understood. This is the case of the link between MDD and inflammation, mitochondrial dysfunction, and oxidative stress. Studies have found that depressive patients usually exhibit altered inflammatory markers, mitochondrial membrane depolarization, oxidized mitochondrial DNA, and thus high levels of both central and peripheral reactive oxygen species (ROS). The effect of antidepressants on these events remains unclear. Nevertheless, the effects of ROS on the brain are well known, including lipid peroxidation of neuronal membranes, accumulation of peroxidation products in neurons, protein and DNA damage, reduced antioxidant defenses, apoptosis induction, and neuroinflammation. Antioxidants such as ascorbic acid, tocopherols, and coenzyme Q have shown promise in some depressive patients, but without consensus on their efficacy. Hence, this paper provides a review of MDD and its association with inflammation, mitochondrial dysfunction, and oxidative stress and is aimed at thoroughly discussing the putative links between these events, which may contribute to the design and development of new therapeutic approaches for patients.

Role of magnetic resonance spectroscopy in cerebral glutathione quantification for youth mental health: A systematic review

AIM

Oxidative stress is strongly implicated in many psychiatric disorders, which has resulted in the development of new interventions to attempt to perturb this pathology. A great deal of attention has been paid to glutathione, which is the brain's dominant antioxidant and plays a fundamental role in removing free radicals and other reactive oxygen species. Measurement of glutathione concentration in the brain in vivo can provide information on redox status and potential for oxidative stress to develop. Glutathione might also represent a marker to assess treatment response.

METHODS

This paper systematically reviews studies that assess glutathione concentration (measured using magnetic resonance spectroscopy) in various mental health conditions.

RESULTS

There is limited evidence showing altered brain glutathione concentration in mental disorders; the best evidence suggests glutathione is decreased in depression, but is not altered in bipolar disorder. The review then outlines the various methodological options for acquiring glutathione data using spectroscopy.

CONCLUSIONS

Analysis of the minimum effect size measurable in existing studies indicates that increased number of participants is required to measure subtle but possibly important differences and move the field forward.

Early-Life Stress Induces Depression-Like Behavior and Synaptic-Plasticity Changes in a Maternal Separation Rat Model: Gender Difference and Metabolomics Study

More than 300 million people suffer from depressive disorders globally. People under early-life stress (ELS) are reportedly vulnerable to depression in their adulthood, and synaptic plasticity can be the molecular mechanism underlying such depression. Herein, we simulated ELS by using a maternal separation (MS) model and evaluated the behavior of Sprague-Dawley (SD) rats in adulthood through behavioral examination, including sucrose preference, forced swimming, and open-field tests. The behavior tests showed that SD rats in the MS group were more susceptible to depression- and anxiety-like behaviors than did the non-MS (NMS) group. Nissl staining analysis indicated a significant reduction in the number of neurons at the prefrontal cortex and hippocampus, including the CA1, CA2, CA3, and DG regions of SD rats in the MS group. Immunohistochemistry results showed that the percentages of synaptophysin-positive area in the prefrontal cortex and hippocampus (including the CA1, CA2, CA3, and DG regions) slice of the MS group significantly decreased compared with those of the NMS group. Western blot analysis was used to assess synaptic-plasticity protein markers, including postsynaptic density 95, synaptophysin, and growth-associated binding protein 43 protein expression in the cortex and hippocampus. Results showed that the expression levels of these three proteins in the MS group were significantly lower than those in the NMS group. LC-MS/MS analysis revealed no significant differences in the peak areas of sex hormones and their metabolites, including estradiol, testosterone, androstenedione, estrone, estriol, and 5β-dihydrotestosterone. Through the application of nontargeted metabolomics to the overall analysis of differential metabolites, pathway-enrichment results showed the importance of arginine and proline metabolism; pantothenate and CoA biosyntheses; glutathione metabolism; and the phenylalanine, tyrosine, and tryptophan biosynthesis pathways. In summary, the MS model caused adult SD rats to be susceptible to depression, which may regulate synaptic plasticity through arginine and proline metabolism; pantothenate and CoA biosyntheses; glutathione metabolism; and phenylalanine, tyrosine, and tryptophan biosyntheses.

Feasibility of Measuring GABA Levels in the Upper Brainstem in Healthy Volunteers Using Edited MRS

PURPOSE

To assess the feasibility of small-voxel MEGA-PRESS in detecting gamma-aminobutyric acid (GABA) levels of the upper brainstem in healthy volunteers.

MATERIALS AND METHODS

Forty-two healthy volunteers, aged between 20 and 76 years were enrolled in this study, and underwent a 3.0T MRI scan using an eight-channel phased-array head coil. The MEGA-PRESS sequence was used to edit GABA signal from a 10x25x30 mm³ voxel in the upper brain stem. The detected signal includes contributions from macromolecules (MM) and homocarnosine and is therefore referred to as GABA+. All the data were processed using Gannet.

RESULTS

Thirty-four cases were successful in measuring GABA in the upper brainstem and 8 cases failed (based on poor modeling of spectra). The GABA+ levels were 2.66 ± 0.75 i.u. in the upper brainstem of healthy volunteers, ranging from 1.50 to 4.40 i.u. The normalized fitting residual (FitErr in Gannet) was 12.1 ± 2.8%, ranging from 7.4% to 19.1%; it was below 15.5% in 30 cases (71%).

CONCLUSIONS

It is possible to measure GABA levels in the upper brainstem using MEGA-PRESS with a relatively small ROI, with a moderate between-subject variance of under 30%.

Unraveling the Serum Metabolomic Profile of Post-partum Depression

Post-partum depression (PPD) is a severe psychiatric disorder affecting ∼15% of young mothers. Early life stressful conditions in periconceptual, fetal and early infant periods or exposure to maternal psychiatric disorders, have been linked to adverse childhood outcomes interfering with physiological, cognitive and emotional development. The molecular mechanisms of PPD are not yet fully understood. Unraveling the molecular underpinnings of PPD will allow timely detection and establishment of effective therapeutic approaches. To investigate the underlying molecular correlates of PPD in peripheral material, we compared the serum metabolomes of an in detail characterized group of mothers suffering from PPD and a control group of mothers, all from Heraklion, Crete in Greece. Serum samples were analyzed by a mass spectrometry platform for targeted metabolomics, based on selected reaction monitoring (SRM), which measures the levels of up to 300 metabolites. In the PPD group, we observed increased levels of glutathione-disulfide, adenylosuccinate, and ATP, which associate with oxidative stress, nucleotide biosynthesis and energy production pathways. We also followed up the metabolomic findings in a validation cohort of PPD mothers and controls. To the very best of our knowledge, this is the first metabolomic serum analysis in PPD. Our data show that molecular changes related to PPD are detectable in peripheral material, thus paving the way for additional studies in order to shed light on the molecular correlates of PPD.

Effects of Platycodins Folium on Depression in Mice Based on a UPLC-Q/TOF-MS Serum Assay and Hippocampus Metabolomics

Major depressive disorder (MDD), also known as depression, is a state characterized by low mood and aversion to activity. Platycodins Folium (PF) is the dried leaf of Platycodon grandiflorum, with anti-inflammatory and antioxidative activities. Our previous research suggested that PF was rich in flavonoids, phenols, organic acids, triterpenoid saponins, coumarins and terpenoids. This study aimed to investigate the antidepressant effect of PF using lipopolysaccharide (LPS)-induced depressive mice. Several behavior tests (sucrose preference test (SPT), forced swimming test (FST) and tail suspension test (TST)) and biochemical parameters (IL-6, TNF-α and SOD levels) were used to evaluate the antidepressive effect of PF on LPS-induced depression model. Furthermore, a UPLC-Q/TOF-MS-based metabolomics approach was applied to explore the latent mechanism of PF in attenuating depression. As a result, a total of 21 and 11 metabolites that potentially contribute to MDD progress and PF treatment were identified in serum and hippocampus, respectively. The analysis of metabolic pathways revealed that lipid metabolism, amino acid metabolism, energy metabolism, arachidonic acid metabolism, glutathione metabolism and inositol phosphate metabolism were disturbed in a model of mice undergoing MDD and PF treatment. These results help us to understand the pathogenesis of depression in depth, and to discover targets for clinical diagnosis and treatment. They also provide the possibility of developing PF into an anti-depressantive agent.