Malondialdehyde plasma concentration correlates with declarative and working memory in patients with recurrent depressive disorder

An Examination into the Effects of a Nutraceutical Supplement on Cognition, Stress, Eye Health, and Skin Satisfaction in Adults with Self-Reported Cognitive Complaints: A Randomized, Double-Blind, Placebo-Controlled Trial

Background: Dietary quality and the consumption of antioxidant-rich foods have been shown to protect against memory decline. Therefore, this double-blind, randomized, placebo-controlled study aimed to investigate the effects of a nutritional supplement on changes in cognitive performance. Methods: In adults aged 40 to 70 years with subjective memory complaints, participants were randomly allocated to take a supplement containing vitamin E, astaxanthin, and grape juice extract daily for 12 weeks or a matching placebo. The primary outcomes comprised changes in cognitive tasks assessing episodic memory, working memory, and verbal memory. Secondary and exploratory measures included changes in the speed of information processing, attention, and self-report measures of memory, stress, and eye and skin health. Moreover, changes in plasma concentrations of brain-derived neurotrophic factor, malondialdehyde, tumor-necrosis factor-α, and interleukin-6 were measured, along with changes in skin carotenoid concentrations. Results: Compared to the placebo, nutritional supplementation was associated with larger improvements in one primary outcome measure comprising episodic memory (p = 0.037), but not for working memory (p = 0.418) or verbal learning (p = 0.841). Findings from secondary and exploratory outcomes demonstrated that the nutraceutical intake was associated with larger improvements in the Everyday Memory Questionnaire (p = 0.022), increased plasma brain-derived neurotrophic factor (p = 0.030), decreased plasma malondialdehyde (p = 0.040), and increased skin carotenoid concentrations (p = 0.006). However, there were no group differences in changes in the remaining outcome measures. Conclusions: Twelve weeks of supplementation with a nutritional supplement was associated with improvements in episodic memory and several biological markers associated with cognitive health. Future research will be essential to extend and validate the current findings.

Neuroprotective Effects of Phenolic Antioxidant Tert-butylhydroquinone (tBHQ) in Brain Diseases

Human life and health are gravely threatened by brain diseases. The onset and progression of the illnesses are influenced by a variety of factors, including pathogenic causes, environmental factors, mental issues, etc. According to scientific studies, neuroinflammation and oxidative stress play a significant role in the development and incidence of brain diseases by producing pro-inflammatory cytokines and oxidative tissue damage to induce inflammation and apoptosis. Neuroinflammation, oxidative stress, and oxidative stress-related changes are inseparable factors in the etiology of several brain diseases. Numerous neurodegenerative diseases have undergone substantial research into the therapeutic alternatives that target oxidative stress, the function of oxidative stress, and the possible therapeutic use of antioxidants. Formerly, tBHQ is a synthetic phenolic antioxidant, which has been widely used as a food additive. According to recent researches, tBHQ can suppress the processes that lead to neuroinflammation and oxidative stress, which offers a fresh approach to treating brain diseases. In order to achieve the goal of decreasing inflammation and apoptosis, tBHQ is a specialized nuclear factor erythroid 2-related factor (Nrf2) activator that decreases oxidative stress and enhances antioxidant status by upregulating the Nrf2 gene and reducing nuclear factor kappa-B (NF-κB) activity. This article reviews the effects of tBHQ on neuroinflammation and oxidative stress in recent years and looks into how tBHQ inhibits neuroinflammation and oxidative stress through human, animal, and cell experiments to play a neuroprotective role in Alzheimer's disease (AD), stroke, depression, and Parkinson's disease (PD). It is anticipated that this article will be useful as a reference for upcoming research and the creation of drugs to treat brain diseases.

Gender-related Characteristics of Oxidative Stress Severity and Cognitive Impairment in Patients With Schizophrenia

The gender specificity of the clinical and psychopathological features of schizophrenia is an important factor in this disease. Gender features of neurocognitive deficit in schizophrenia and associated functional and structural disorders of the brain activity are of particular interest to researchers. There are several potential pathogenetic factors of this disease associated with gender, one of which is considered to be oxidative stress. Stress-induced cell death in the prefrontal and anterior frontal regions and reduced brain volume in these regions lead to cognitive and executive decline in patients with schizophrenia. Despite the great interest in the gender factor in schizophrenia pathogenesis, there are currently very few studies on gender differences in the severity of redox imbalance in patients with schizophrenia and their association with neurocognitive deficit. The aim of the study was to reveal the gender specificity of oxidative stress severity in patients with schizophrenia and assess its association with the severity of neurocognitive deficit. The study included 125 patients with schizophrenia and 75 sex- and age-matched healthy volunteers. Sociodemographic and clinical data were studied. Cognitive functions were evaluated using BACS. Blood samples were taken for biochemical studies of the levels of reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) in erythrocyte hemolysate, malonic dialdehyde (MDA), aldehyde-2,4-dinitrophenylhydrazones (ADNPH), ketone-2,4-dinitrophenylhydrazones (KDNPH) in plasma. Levels of oxidative stress markers were assessed by spectrophotometric method. In a sample of patients with schizophrenia, a statistically significantly higher activity of CAT was revealed among women compared to men (T=2.25; p=0.025), however, it was lower than in healthy volunteers. But, at the same time, a higher concentration of protein peroxidation products was found in the peripheral blood of women than in men (ADNPH MCO: T=2.52; p=0.013; KDNPH MCO: Z=-2.26; p=0.017). In the group of healthy volunteers, in contrast to patients with schizophrenia, gender differences in markers of oxidative stress were not found. In women with schizophrenia, single correlations were found between the level of the lipid peroxidation product MDA and the test scores for verbal memory (R=-0.36; p=0.006) and working memory (R=-0.36; p=0.006), antioxidant enzyme activity SOD and motor skills (R=-0.26; p=0.047). In men, on the contrary, multiple correlations of both antioxidants and, mainly, products of lipid and protein peroxidation with cognitive functions assessed using BACS were found. Despite the fact that oxidative stress is more pronounced in women than in men with schizophrenia, associations of redox imbalance with neurocognitive deficit in women is much less pronounced than in men.

Possible involvement of l-arginine-nitric oxide pathway in the antidepressant activity of Auraptene in mice

Background

Depression is one of the most common mental illnesses worldwide. Nitric oxide (NO) is involved in the pathophysiology of depression. Auraptene (a coumarin derivative) has been shown to possess pharmacological effects on neurological diseases.

Purpose

The present study aimed to investigate the possible role of the NO pathway in Auraptene antidepressant effects in male mice.

Methods

Behavioral tests were used to assess depression-like behaviors. The mice received Auraptene at 10, 30, and 100 mg/kg, the combination of the sub-effective (ineffective) dose of Auraptene (10 mg/kg) and L-NAME, and the combination of the effective dose of Auraptene (30 mg/kg) and L-arginine. Finally, OFT, TST, FST, brain, serum MDA level, antioxidant capacity, hippocampus, and serum NO level were measured.

Results

The data analysis showed that Auraptene (30 mg/kg) improved depression-like behaviors. Auraptene (30 mg/kg) also significantly reduced serum NO levels (P < 0.05) and significantly increased serum MDA (10 mg/kg, P < 0.05). Auraptene at 30 mg/kg also increased serum antioxidant capacity (P < 0.01). Co-administration of L-NAME and the sub-effective dose of Auraptene enhanced the effects of Auraptene. However, co-administration of the effective dose of Auraptene and L-arginine reduced the impacts of Auraptene.

Conclusions

The results showed that Auraptene causes antidepressant effects in a dose-dependent manner and acts as a prooxidant at 100 mg/kg, and exacerbates oxidative stress. The antidepressant effects of this active molecule are exerted by reducing the NO level in the hippocampus and serum, increasing the antioxidant capacity, and reducing the MDA level in the serum.

C-Reactive Protein as a Biomarker for Major Depressive Disorder?

The etiopathogenesis of depression is not entirely understood. Several studies have investigated the role of inflammation in major depressive disorder. The present work aims to review the literature on the association between C-Reactive Protein (CRP) and depression. A systematic review was performed for the topics of ‘CRP’ and ‘depression’ using the PubMed database from inception to December 2021. Fifty-six studies were identified and included in the review. Evidence suggested the presence of dysregulation in the inflammation system in individuals with depression. In most studies, higher blood CRP levels were associated with greater symptom severity, a specific pattern of depressive symptoms, and a worse response to treatment. Moreover, about one-third of depressed patients showed a low-grade inflammatory state, suggesting the presence of a different major depressive disorder (MDD) subgroup with a distinct etiopathogenesis, clinical course, treatment response, and prognosis, which could benefit from monitoring of CRP levels and might potentially respond to anti-inflammatory treatments. This work provides robust evidence about the potential role of CRP and its blood levels in depressive disorders. These findings can be relevant to developing new therapeutic strategies and better understanding if CRP may be considered a valuable biomarker for depression.

Efficacy of a novel proprietary dietary supplement (TRI 360TM) on psychological symptoms and stress-related quality of life in adult subjects: A randomized controlled clinical trial

Nowadays, diet plays an increasingly important role in normal physiology and mental health. Recently, many studies have shown that more use of dietary supplements in mental and psychological disorders. Study objective was to investigate safety and efficacy of proprietary nutraceutical combination (TRI 360^TM) on psychological symptoms in adult human subjects with one or more psychological symptoms in open-label, single-center, parallel-group, randomized controlled trial. Eighty-four participants aged 20-45 years with psychological symptoms were completed this trial. Participants were randomly assigned to placebo and treatment groups. Treatment group received TRI 360^TM capsules twice a day. TRI 360^TM was well-tolerated and didn't show treatment-related adverse-events upto 180 days. All assessed perception scorings on psychological symptoms like fatigue, mental stress, sleep disturbance, anxiety, depression, emotional trauma, mood changes, self-confidence, willpower, and motivation were very significantly (p ≤ 0.0001) improved in TRI 360^TM participants than placebo control group. Furthermore, significantly (p ≤ 0.001) increased levels of functional biomarkers: vitamin C and D₃ metabolites, neurotransmitters, hormones, antiaging protein (klotho) level; and decreased proinflammatory cytokines and oxidative stress marker, malondialdehyde in TRI 360^TM group than placebo. According to these findings, the use of TRI 360^TM supplementation as a potentially safe therapeutic option for reducing psychological symptoms in healthy adults.

Circulatory antioxidant and oxidative stress markers are in correlation with demographics but not cognitive functions in multiple sclerosis patients

BACKGROUND

Multiple sclerosis (MS) is the most common non-traumatic cause of disability in younger adults. MS can be presented with a wide range of symptoms such as cognitive impairment (CI). Oxidative stress (OXS) is a major basis of the pathogenesis of MS. There is a positive correlation between OXS factors and the progression of the disease in MS patients. There are limited studies regarding the role of OXS in MS-related CI. In this study, as an exploratory analysis, we assess the role of endogenous antioxidants and OXS factors in cognitive function, the severity of disability due to MS, and demographic findings in a sample of MS patients.

METHODS

Adult (>18 years old) patients with a definite diagnosis of MS based on 2017 revised MacDonald criteria were included in this study. The neurophysiological assessment was conducted, using the validated Persian version of minimal assessment of cognitive function in multiple sclerosis (MACFIMS) battery, which is composed of seven different tests. Based on the structure of the battery, CI was defined as a failure in at least two different components of the MACFIMS battery. The patients were separated into two groups of CI and non-CI. Examined antioxidant factors included catalase Activity (CAT), Glutathione Peroxidase 1 (GPX1), Glutathione Peroxidase 2 (GPX2), Reduced Glutathione (GSH), Superoxide Dismutase (SOD), and serum total antioxidant capacity (TAC). Malondialdehyde (MDA) was also measured as an OXS marker.

RESULTS

71 patients were involved in this study. The type of MS was relapsing-remitting MS (RRMS) in 80.28% of the participants. Disease duration (P<0.01), type of MS (p<0.01), and EDSS score (p<0.01) were different between CI and non-CI groups, but there were not any significant differences in CAT (p = 0.80), GPX1 (p = 0.71), GPX2 (p = 0.41), GSH (p = 0.96), TAC (p = 0.13), SOD (p = 0.37), and MDA (p = 0.82). A significant difference between RRMS and progressive MS (PMS) patients in the levels of GPX1 (p = 0.01), GPX2 (p = 0.01), and SOD (p = 0.01) was observed. Also, we found higher circulatory levels of CAT (p = 0.02) and TAC (p<0.01) in male MS patients. We found significant correlations between aging and CAT (R = 0.28; p = 0.01), GPX1 (R = 0.36; p<0.01), GPX2 (R = 0.34; p<0.01), and SOD (R = 0.40; p<0.01). EDSS, the duration of the disease, relapse rate, and the number of impaired cognitive tasks were not correlated with any of investigated OXS or antioxidant factors (p>0.05). In terms of a detailed investigation of associations between MACFIMS battery components and levels of OXS and antioxidant factors, there were no significant relations in this regard (p>0.05). Based on the logistic regression multivariate analysis, only disease duration (p = 0.03) and GPX1 (p = 0.01) were independently associated with CI in MS patients in our sample.

CONCLUSION

The circulatory levels of GPX1, GPX2, and SOD are significantly different between RRMS and PMS patients. Neither endogenous antioxidants nor MDA, as an OXS biomarker, are associated with the cognitive function or level of physical disability in MS patients. Limitations of this study suggest a need for future studies in a larger sample of MS patients.

Estimated Phytate Intake Is Associated with Improved Cognitive Function in the Elderly, NHANES 2013-2014

Phytate, an antioxidant, may improve cognition by inhibiting iron catalyzed hydroxyl radical formation. Particularly in the elderly, this provides a potential dietary approach for mitigating age-related brain neuronal dysfunction and loss. In this study, we investigated the relationship between phytate intake and cognitive function in the elderly. We used data from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) and the corresponding Food Patterns Equivalents Database (FPED). Phytate content of food groups from published data were merged with the appropriate FPED data to estimate the total phytate intake for each subject. Principal component analysis was used to develop a composite score from four cognitive function scores in NHANES data, and regression analysis was used to determine the relationship between this score and phytate intake. Median phytate intake was 0.65 (0.61, 0.71) g/day. It was low among females, non-Hispanic blacks, and people with history of at least one chronic disease (p < 0.05). In regression analysis adjusted for confounders, phytate intake was positively associated with cognitive function (β (95% CI) = 1.90 (0.73-3.07); p = 0.015). These results suggest that phytate may be associated with improved cognition, hence the need to consider including phytate-rich foods in the diet among the elderly.

Malondialdehyde concentrations in obsessive-compulsive disorder: a systematic review and meta-analysis

BACKGROUND

This meta-analysis aimed to investigate serum and plasma malondialdehyde (MDA) levels in patients with obsessive-compulsive disorder (OCD) in comparison to healthy controls.

METHODS

Following the PRISMA protocol, we searched for the relevant studies through the databases of Scopus, PubMed, Google Scholar, and web of science until September 2019 with no time restriction. Overall, nine studies were included in the current meta-analysis. Data were pooled using a random-effects model; in addition, standard mean difference (SMD) and/or weight mean difference (WMD) was calculated. Cochran's Q test and I-square (I2) statistics were used to evaluate between-study heterogeneity. The Newcastle-Ottawa scale (NOS) was used to evaluate the quality of the included studies. Statistical analyses were done using the STATA version 14.

RESULTS

Our systematic review included nine case-control studies (including 367 cases and 337 controls). Pooling findings from these studies showed a significantly higher MDA level in OCD patient compared to control groups (SMD = 1.62; 95% CI [0.53, 2.72]; I2 = 96.9%; Pheterogeneity (Ph) < 0.001). This finding remained unchanged among studies which reported MDA in the same unit (WMD = 1.93; 95% CI [0.27, 3.59]; I2 = 99.2%; Ph < 0.001). Subgroup analysis by the study location and sample size revealed findings that were also significant.

CONCLUSION

We found that MDA levels are higher in OCD patients than healthy controls. This finding highlights the importance of inflammatory responses in OCD patients that should be considered for future investigations. Further studies are recommended to expand current knowledge on this issue.

Inflammation as the Common Biological Link Between Depression and Cardiovascular Diseases: Can Carnosine Exert a Protective Role?

Several epidemiological studies have clearly shown the high co-morbidity between depression and Cardiovascular Diseases (CVD). Different studies have been conducted to identify the common pathophysiological events of these diseases such as the overactivation of the hypothalamic- pituitary-adrenal axis and, most importantly, the dysregulation of immune system which causes a chronic pro-inflammatory status. The biological link between depression, inflammation, and CVD can be related to high levels of pro-inflammatory cytokines, such as IL-1β, TNF-α, and IL-6, released by macrophages which play a central role in the pathophysiology of both depression and CVD. Pro-inflammatory cytokines interfere with many of the pathophysiological mechanisms relevant to depression by upregulating the rate-limiting enzymes in the metabolic pathway of tryptophan and altering serotonin metabolism. These cytokines also increase the risk to develop CVD, because activation of macrophages under this pro-inflammatory status is closely associated with endothelial dysfunction and oxidative stress, a preamble to atherosclerosis and atherothrombosis. Carnosine (β-alanyl-L-histidine) is an endogenous dipeptide which exerts a strong antiinflammatory activity on macrophages by suppressing reactive species and pro-inflammatory cytokines production and altering pro-inflammatory/anti-inflammatory macrophage polarization. This dipeptide exhibits antioxidant properties scavenging reactive species and preventing oxidative stress-induced pathologies such as CVD. In the present review we will discuss the role of oxidative stress and chronic inflammation as common pathophysiological events both in depression and CVD and the preclinical and clinical evidence on the protective effect of carnosine in both diseases as well as the therapeutic potential of this dipeptide in depressed patients with a high co-morbidity of cardiovascular diseases.

Anti-inflammatory effect of selenium on lead-induced testicular inflammation by inhibiting NLRP3 inflammasome activation in chickens

Lead (Pb) is a deleterious environmental pollutant that is toxic to testes. Selenium (Se) possesses antioxidant and anti-inflammatory properties. Nucleotide-binding domain, leucine-rich-containing family, pyrin-domain containing-3 (NLRP3) inflammasome is involved in inflammatory response. However, the function of NLRP3 inflammasome in antagonistic effect of Se on inflammation caused by Pb remains unknown. The purpose of this research is to identify anti-inflammatory role of Se on testicular toxicity induced by Pb with an emphasis on oxidative stress, inflammation and NLRP3 signaling pathway in chicken. In present study, sixty seven-day-old Hyline male chickens were assigned into four groups. The feeding program consisted of a commercial diet (0.49 mg/kg Se), a Se-supplemented diet (1 mg/kg Se), a Pb-supplemented diet (0.49 mg/kg Se and 350 mg/kg Pb) and a Se-supplemented and Pb-supplemented diet (1 mg/kg Se and 350 mg/kg Pb), respectively. On the 12th week, blood was collected to measure serum testosterone level and testicular tissues were removed to determine Se and Pb concentrations, testicular function, histological structure, oxidative stress indicators and inflammation-related factors (Nuclear factor-kappaB, tumor necrosis factor-α, cyclooxygenase-2, NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain, caspase-1, interluekin (IL)-1β, IL-6, IL-18 and interferon-γ). The experimental results showed that after Pb administration, testicular injury was confirmed via histological assessment; testicular dysfunction were further indicated by decreased testosterone level and mRNA expression of steroidogenic acute regulatory protein, cytochrome P450 side-chain cleavage, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase. Moreover, NLRP3 signaling pathway activated by Pb-caused oxidative stress was up-regulated accompanied by promotion in reactive oxygen species, nitric oxide, inducible nitric oxide synthase and malondialdehyde and reduction in antioxidants including glutathione peroxidase and glutathione s-transferase. Se administration ameliorated testicular tissue injury, testicular function, oxidative stress and inflammation. In conclusion, Se exhibited antagonistic role in Pb-induced testicular injury via enhancing antioxidant system and inhibiting inflammation in chickens.

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.

Oxidation-reduction mechanisms in psychiatric disorders: A novel target for pharmacological intervention

While neurotransmitter dysfunction represents a key component in mental illnesses, there is now a wide agreement for a central pathophysiological hub that includes hormones, neuroinflammation, redox mechanisms as well as oxidative stress. With respect to oxidation-reduction (redox) mechanisms, preclinical and clinical evidence suggests that an imbalance in the pro/anti-oxidative homeostasis toward the increased production of substances with oxidizing potential may contribute to the etiology and manifestation of different psychiatric disorders. The substantial and continous demand for energy renders the brain highly susceptible to disturbances in its energy supply, especially following exposure to stressful events, which may lead to overproduction of reactive oxygen and nitrogen species under conditions of perturbed antioxidant defenses. This will eventually induce different molecular alterations, including extensive protein and lipid peroxidation, increased blood-brain barrier permeability and neuroinflammation, which may contribute to the changes in brain function and morphology observed in mental illnesses. This view may also reconcile different key concepts for psychiatric disorders, such as the neurodevelopmental origin of these diseases, as well as the vulnerability of selective cellular populations that are critical for specific functional abnormalities. The possibility to pharmacologically modulate the redox system is receiving increasing interest as a novel therapeutic strategy to counteract the detrimental effects of the unbalance in brain oxidative mechanisms. This review will describe the main mechanisms and mediators of the redox system and will examine the alterations of oxidative stress found in animal models of psychiatric disorders as well as in patients suffering from mental illnesses, such as schizophrenia and major depressive disorder. In addition, it will discuss studies that examined the effects of psychotropic drugs, including antipsychotics and antidepressants, on the oxidative balance as well as studies that investigated the effectiveness of a direct modulation of oxidative mechanisms in counteracting the behavioral and functional alterations associated with psychiatric disorders, which supports the promising role of the redox system as a novel therapeutic target for the improved treatment of brain disorders.

DNA damage and repair in neuropsychiatric disorders. What do we know and what are the future perspectives?

Over the past two decades, extensive research has been done to elucidate the molecular etiology and pathophysiology of neuropsychiatric disorders. In majority of them, including Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), bipolar disorder (BD), schizophrenia and major depressive disorder, increased oxidative and nitrosative stress was found. This stress is known to induce oxidative damage to biomolecules, including DNA. Accordingly, increased mitochondrial and nuclear DNA, as well as RNA damage, were observed in patients suffering from these diseases. However, recent findings indicate that the patients are characterised by impaired DNA repair pathways, which may suggest that these DNA lesions could be also a result of their insufficient repair. In the current systematic, critical review, we aim to sum up, using available literature, the knowledge about the involvement of nuclear and mitochondrial DNA damage and repair, as well as about damage to RNA in pathoetiology of neuropsychiatric disorders, i.e., AD, PD, ALS, BD, schizophrenia and major depressive disorder, as well as the usefulness of the discussed factors as being diagnostic markers and targets for new therapies. Moreover, we also underline the new directions to which future studies should head to elucidate these phenomena.

Depression and anxiety symptoms are associated with prooxidant-antioxidant balance: A population-based study

BACKGROUND

Depression and anxiety are significantly associated with systemic inflammation. Moreover, oxidative stress resulting from a disturbance in the prooxidant-antioxidant balance is linked to inflammation-related conditions. Therefore, depression/anxiety symptoms may also be associated with oxidative stress.

OBJECTIVE

To examine the association between depression/anxiety symptoms and serum prooxidant-antioxidant balance (PAB) in adults who participated in a large population-based, cross-sectional study.

METHODS

Serum PAB values were measured in 7516 participants (62% females and 38% males) aged 35-65 years, enrolled in a population-based cohort study. beck depression and anxiety inventories were used to evaluate symptoms of depression and anxiety. Multinomial logistic regression was used to examine the effect of confounders on the status of serum PAB change.

RESULTS

Among men, serum PAB values were increased incrementally from 1.55 ± 0.47 to 1.59 ± 0.47, 1.69 ± 0.38, and 1.68 ± 0.38 in the no or minimal, mild, moderate and severe depression groups, respectively (P_trend< 0.001). Serum PAB values also increased significantly across these four corresponding groups among women [1.70 ± 0.45, 1.73 ± 0.44, 1.75 ± 0.44, and 1.76 ± 0.40, (P_trend= 0.005)]. About anxiety, serum PAB values increased significantly across the four groups in men (P_trend= 0.02) but not in women (P_trend= 0.2). The adjusted odds ratios for serum PAB values among men with severe depression and anxiety symptoms were 1.75 and 1.27, respectively. Moreover, the adjusted odds ratios for serum PAB values among women with severe depression and anxiety symptoms were 1.40 and 1.17, respectively.

CONCLUSION

Symptoms of depression and anxiety appear to be associated with higher degrees of oxidative stress, expressed by higher serum PAB values.

The interplay between inflammation, oxidative stress, DNA damage, DNA repair and mitochondrial dysfunction in depression

A growing body of evidence suggests that inflammation, mitochondrial dysfunction and oxidant-antioxidant imbalance may play a significant role in the development and progression of depression. Elevated levels of reactive oxygen and nitrogen species - a result of oxidant-antioxidant imbalance - may lead to increased damage of biomolecules, including DNA. This was confirmed in depressed patients in a research study conducted by our team and other scientists. 8-oxoguanine - a marker of oxidative DNA damage - was found in the patients' lymphocytes, urine and serum. These results were confirmed using a comet assay on lymphocytes. Furthermore, it was shown that the patients' cells repaired peroxide-induced DNA damage less efficiently than controls' cells and that some single nucleotide polymorphisms (SNP) of the genes involved in oxidative DNA damage repair may modulate the risk of depression. Lastly, less efficient DNA damage repair observed in the patients can be, at least partly, attributed to the presence of specific SNP variants, as it was revealed through a genotype-phenotype analysis. In conclusion, the available literature shows that both oxidative stress and less efficient DNA damage repair may lead to increased DNA damage in depressed patients. A similar mechanism may result in mitochondrial dysfunction, which is observed in depression.

Chronic stress causes protein kinase C epsilon-aldehyde dehydrogenase 2 signaling pathway perturbation in the rat hippocampus and prefrontal cortex, but not in the myocardium

Chronic stress is strongly associated with the occurrence and development of depression and cardiovascular disease. Stress can induce altered mitochondrial function and activation of apoptosis in the cardio-cerebral system. However, it is unknown whether the protein kinase C ε (PKCε)-aldehyde dehydrogenase 2 (ALDH2) pathway is altered under chronic stress, and this study sought to address this question. A rat model of depression was established using a chronic unpredictable mild stress (CUMS) protocol. After experiencing CUMS for 4 weeks, the sucrose preference test and the forced swim test verified depressive-like behaviors. Enzyme linked immunosorbent assays showed that ALDH2 activity was decreased in the rat hippocampus and prefrontal cortex, but was not altered in the myocardium. Western blot assays demonstrated reduced levels of ALDH2 and PKCε, but increased levels of 4-hydroxy-2-nonenal (4HNE) adducts. Caspase-3 expression did not obviously alter, but active forms of caspase-3 were increased in the hippocampus and prefrontal cortex. In the myocardium, expression of ALDH2, PKCε and 4HNE adducts did not remarkably alter; while caspase-3 expression was reduced and the active forms of caspase-3 were upregulated. Pearson’s correlation test demonstrated that expression of 4HNE adducts was positively correlated with levels of the active forms of caspase-3 in the hippocampus and prefrontal cortex, but not in the myocardium. In conclusion, chronic stress can damage the PKCε-ALDH2 signaling pathway in the hippocampus and prefrontal cortex, but not in the myocardium. Moreover, 4HNE is associated with active forms of caspase-3 in the hippocampus and prefrontal cortex.

Post-Operative Cognitive Dysfunction: An exploration of the inflammatory hypothesis and novel therapies

Post-Operative Cognitive Dysfunction (POCD) is a highly prevalent condition with significant clinical, social and financial impacts for patients and their communities. The underlying pathophysiology is becoming increasingly understood, with the role of neuroinflammation and oxidative stress secondary to surgery and anaesthesia strongly implicated. This review aims to describe the putative mechanisms by which surgery-induced inflammation produces cognitive sequelae, with a focus on identifying potential novel therapies based upon their ability to modify these pathways.

Molecular Mechanisms Underlying the Anti-depressant Effects of Resveratrol: a Review

Major depression is a public health problem, affecting 121 million people worldwide. Patients suffering from depression present high rates of morbidity, causing profound economic and social impacts. Furthermore, patients with depression present cognitive impairments, which could influence on treatment adherence and long-term outcomes. The pathophysiology of major depression is not completely understood yet but involves reduced levels of monoamine neurotransmitters, bioenergetics, and redox disturbances, as well as inflammation and neuronal loss. Treatment with anti-depressants provides a complete remission of symptoms in approximately 50% of patients with major depression. However, these drugs may cause side effects, as sedation and weight gain. In this context, there is increasing interest in studies focusing on the anti-depressant effects of natural compounds found in the diet. Resveratrol is a polyphenolic phytoalexin (3,4',5-trihydroxystilbene; C₁₄H₁₂O₃; MW 228.247 g/mol) and has been found in peanuts, berries, grapes, and wine and induces anti-oxidant, anti-inflammatory, and anti-apoptotic effects in several mammalian cell types. Resveratrol also elicits anti-depressant effects, as observed in experimental models using animals. Therefore, resveratrol may be viewed as a potential anti-depressant agent, as well as may serve as a model of molecule to be modified aiming to ameliorate depressive symptoms in humans. In the present review, we describe and discuss the anti-depressant effects of resveratrol focusing on the mechanism of action of this phytoalexin in different experimental models.

Serum ApoB levels in depressive patients: associated with cognitive deficits

Cognitive deficits have been regarded as one of the most significant clinical symptoms of depressive disorder. Accumulating evidence has shown that apolipoprotein B (ApoB) levels, which are responsible for inducing neurodegeneration, may be involved in cognitive deficits. This study examines cognitive deficits, and the correlation of serum ApoB levels with cognitive deficits of depressive disorder. 90 depressive patients and 90 healthy controls with matched age and gender were recruited. Cognition was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Serum ApoB levels in depressive patients were measured by immunoturbidimetric method. Our results showed that depressive patients had lower scores of cognition including RBANS total score and subscales of language and delayed memory (all, p < 0.001) than healthy controls after controlling for the variables. The differences in cognitive functions also passed Bonferroni corrections. Serum ApoB levels were negatively correlated with delayed memory score in depressive patients (r = −0.30, p = 0.01). Furthermore, stepwise multivariate regression analysis indicated that serum ApoB levels independently contributed to delayed memory in depressive patients (t = −2.68, p = 0.01). Our findings support that serum ApoB levels may be involved in delayed memory decline in depressive patients. Depressive patients also experience greater cognitive deficits, especially in delayed memory and language than healthy controls.

The role of oxidative and nitrosative stress in accelerated aging and major depressive disorder

Major depressive disorder (MDD) affects millions of individuals and is highly comorbid with many age associated diseases such as diabetes mellitus, immune-inflammatory dysregulation and cardiovascular diseases. Oxidative/nitrosative stress plays a fundamental role in aging, as well as in the pathogenesis of neurodegenerative/neuropsychiatric disorders including MDD. In this review, we critically review the evidence for an involvement of oxidative/nitrosative stress in acceleration of aging process in MDD. There are evidence of the association between MDD and changes in molecular mechanisms involved in aging. There is a significant association between telomere length, enzymatic antioxidant activities (SOD, CAT, GPx), glutathione (GSH), lipid peroxidation (MDA), nuclear factor κB, inflammatory cytokines with MDD. Major depression also is characterized by significantly lower concentration of antioxidants (zinc, coenzyme Q10, PON1). Since, aging and MDD share a common biological base in their pathophysiology, the potential therapeutic use of antioxidants and anti-aging molecules in MDD could be promising.

Oxidative stress and cognition amongst adults without dementia or stroke: Implications for mechanistic and therapeutic research in psychiatric disorders

Oxidative stress has been implicated in cognitive deficits in disease states such as dementia and stroke. However, growing evidence shows similar associations in individuals without these conditions. We therefore set out to systematically review the literature on this topic. MEDLINE searches were conducted of medical subject-headings neuropsychology, cognition, cognition disorders, or neuropsychological tests, cross-referenced with oxidative stress, or superoxide. Exclusion criteria were dementia and stroke studies, absence of human subjects, and absence of quantifiable oxidative stress/cognition measures. The search yielded 883 results, of which 19 studies (consisting of 3662 total subjects) were included in this review. The majority of studies indicated that frontal cognitive functions were most often impaired, and lipid peroxidation was most commonly associated with impairments. Literature on learning, memory, and general cognitive function was less robust. A substantial proportion of the literature on this topic is based on psychiatric populations. Frontal-executive dysfunction implicates frontal brain regions, which are known to be susceptible to oxidative damage. Further studies are needed, and those examining psychiatric populations may be especially fruitful. Focusing on youth may yield enhanced signal detection. Further study is needed to identify which antioxidant interventions work best for which cognitive functions and for which patients.

Mechanisms underlying neurocognitive dysfunctions in recurrent major depression

Recent work shows that depression is intimately associated with changes in cognitive functioning, including memory, attention, verbal fluency, and other aspects of higher-order cognitive processing. Changes in cognitive functioning are more likely to occur when depressive episodes are recurrent and to abate to some degree during periods of remission. However, with accumulating frequency and duration of depressive episodes, cognitive deficits can become enduring, being evident even when mood improves. Such changes in cognitive functioning give depression links to mild cognitive impairment and thereby with neurodegenerative conditions, including Alzheimer’s disease, Parkinson’s disease, schizophrenia, and multiple sclerosis. Depression may then be conceptualized on a dimension of depression – mild cognitive impairment – dementia. The biological underpinnings of depression have substantial overlaps with those of neurodegenerative conditions, including reduced neurogenesis, increased apoptosis, reactive oxygen species, tryptophan catabolites, autoimmunity, and immune-inflammatory processes, as well as decreased antioxidant defenses. These evolving changes over the course of depressive episodes drive the association of depression with neurodegenerative conditions. As such, the changes in cognitive functioning in depression have important consequences for the treatment of depression and in reconceptualizing the role of depression in wider neuroprogressive conditions. Here we review the data on changes in cognitive functioning in recurrent major depression and their association with other central conditions.

Oxidative stress and major depression

BACKGROUND

Major causative factor for major depression is inflammation, autoimmune tissue damage and prolonged psychological stress, which leads to oxidative stress. The aim of this study was to know the association of free radicals and antioxidant status in subjects suffering from major depression.

MATERIALS AND METHODS

Sixty patients diagnosed as a case of unipolar depression as per DSM IV, fulfilling the inclusion and exclusion criteria were compared with 40 healthy age and sex matched controls. The sera of both the groups were collected taking aseptic precautions and were evaluated for the markers of oxidative stress and for the antioxidants. The age group of the sample and the controls was between 18-60 y, both males and females were equally represented in the groups.

RESULTS

A significantly high level of malondialdehyde (MDA) was found in the patients with major depression (1.95 ± 1.04 mmol/L) as compared to healthy controls (0.366 ± 0.175 mmol/L) (p < 0.0001). The serum level of nitrite was found to be lower in cases (23.18 ± 12.08 μmol/L) in comparison to controls (26.18 ± 8.68 μmol/L) (p = 0.1789). Similarly the serum level of ascorbic acid and superoxide dismutase (SOD) were significantly below as compared to healthy controls (all p < 0.0001). Ceruloplasmin levels were also depressed in cases (p = 0.3943).

CONCLUSION

The study concluded that in the absence of known oxidative injury causative agents, the lowered levels of antioxidants and higher levels of MDA implicate the high degree of oxidative stress in unipolar depression.

Impact of oxidative/nitrosative stress and inflammation on cognitive functions in patients with recurrent depressive disorders

Data show that up to 38.2% of the European population have a mental disorder and that recurrent depressive disorder (rDD) is among the most commonly diagnosed disabling diseases. Over the last few years, neurocognitive impairments in rDD have become a new research front focusing on the role of cognitive decline during the course of rDD and in relation to its clinical presentation and prognosis. Both immune-inflammatory and oxidative and nitrosative stress (O&NS) processes potentially play a role in development of cognitive dysfunction in rDD. New evidence shows that chronic inflammatory and O&NS reactions occur in the brains of patients with neurodegenerative disorders and those with rDD. This narrative review presents the current state of knowledge on the possible impact of selected inflammatory and O&NS enzymes on cognitive functioning in patients with rDD. We focus on manganese superoxide dismutase (MnSOD), inducible nitric oxide synthase (iNOS), and myeloperoxidase (MPO).

Synaptic plasticity in depression: molecular, cellular and functional correlates

Synaptic plasticity confers environmental adaptability through modification of the connectivity between neurons and neuronal circuits. This is achieved through changes to synapse-associated signaling systems and supported by complementary changes to cellular morphology and metabolism within the tripartite synapse. Mounting evidence suggests region-specific changes to synaptic form and function occur as a result of chronic stress and in depression. Within subregions of the prefrontal cortex (PFC) and hippocampus structural and synapse-related findings seem consistent with a deficit in long-term potentiation (LTP) and facilitation of long-term depression (LTD), particularly at excitatory pyramidal synapses. Other brain regions are less well-studied; however the amygdala may feature a somewhat opposite synaptic pathology including reduced inhibitory tone. Changes to synaptic plasticity in stress and depression may correlate those to several signal transduction pathways (e.g. NOS-NO, cAMP-PKA, Ras-ERK, PI3K-Akt, GSK-3, mTOR and CREB) and upstream receptors (e.g. NMDAR, TrkB and p75NTR). Deficits in synaptic plasticity may further correlate disrupted brain redox and bioenergetics. Finally, at a functional level region-specific changes to synaptic plasticity in depression may relate to maladapted neurocircuitry and parallel reduced cognitive control over negative emotion.

Schizophrenia is primed for an increased expression of depression through activation of immuno-inflammatory, oxidative and nitrosative stress, and tryptophan catabolite pathways

Schizophrenia and depression are two common and debilitating psychiatric conditions. Up to 61% of schizophrenic patients have comorbid clinical depression, often undiagnosed. Both share significant overlaps in underlying biological processes, which are relevant to the course and treatment of both conditions. Shared processes include changes in cell-mediated immune and inflammatory pathways, e.g. increased levels of pro-inflammatory cytokines and a Th1 response; activation of oxidative and nitrosative stress (O&NS) pathways, e.g. increased lipid peroxidation, damage to proteins and DNA; decreased antioxidant levels, e.g. lowered coenzyme Q10, vitamin E, glutathione and melatonin levels; autoimmune responses; and activation of the tryptophan catabolite (TRYCAT) pathway through induction of indoleamine-2,3-dioxygenase. Both show cognitive and neurostructural evidence of a neuroprogressive process. Here we review the interlinked nature of these biological processes, suggesting that schizophrenia is immunologically primed for an increased expression of depression. Such a conceptualization explains, and incorporates, many of the current perspectives on the nature of schizophrenia and depression, and has implications for the nature of classification and treatment of both disorders. An early developmental etiology to schizophrenia, driven by maternal infection, with subsequent impact on offspring immuno-inflammatory responses, creates alterations in the immune pathways, which although priming for depression, also differentiates the two disorders.

Synergist effects of n-acetylcysteine and deferoxamine treatment on behavioral and oxidative parameters induced by chronic mild stress in rats

A growing body of evidence has pointed to a relationship between oxidative stress and depression. Thus, the present study was aimed at evaluating the effects of the antioxidants n-acetylcysteine (NAC), deferoxamine (DFX) or their combination on sweet food consumption and oxidative stress parameters in rats submitted to 40days of exposure to chronic mild stress (CMS). Our results showed that in stressed rats treated with saline, there was a decrease in sweet food intake and treatment with NAC or NAC in combination with DFX reversed this effect. Treatment with NAC and DFX decreased the oxidative damage, which include superoxide and TBARS production in submitochondrial particles, and also thiobarbituric acid reactive substances (TBARS) levels and carbonyl proteins in the prefrontal cortex, amygdala and hippocampus. Treatment with NAC and DFX also increased the activity of the antioxidant enzymes, superoxide dismutase and catalase in the same brain areas. Even so, a combined treatment with NAC and DFX produced a stronger increase of antioxidant activities in the prefrontal cortex, amygdala and hippocampus. The results described here indicate that co-administration may induce a more pronounced antidepressant activity than each treatment alone. In conclusion, these results suggests that treatment with NAC or DFX alone or in combination on oxidative stress parameters could have positive effects against neuronal damage caused by oxidative stress in major depressive disorders.