Association between erythrocyte n-3 polyunsaturated fatty acids and biomarkers of inflammation and oxidative stress in patients with and without depression

Major Depressive Disorder and Oxidative Stress: A Review of Peripheral and Genetic Biomarkers According to Clinical Characteristics and Disease Stages

Major depressive disorder (MDD) is currently the main cause of disability worldwide, but its pathophysiology remains largely unknown, especially given its high heterogeneity in terms of clinical phenotypes and biological characteristics. Accordingly, its management is still poor. Increasing evidence suggests that oxidative stress, measured on various matrices such as serum, plasma or erythrocytes, has a critical role in MDD. The aim of this narrative review is to identify serum, plasma and erythrocyte biomarkers of oxidative stress in MDD patients according to disease stage and clinical features. Sixty-three articles referenced on PubMed and Embase between 1 January 1991, and 31 December 2022, were included. Modifications to antioxidant enzymes (mainly glutathione peroxidase and superoxide dismutase) in MDD were highlighted. Non-enzymatic antioxidants (mainly uric acid) were decreased in depressed patients compared to healthy controls. These changes were associated with an increase in reactive oxygen species. Therefore, increased oxidative damage products (principally malondialdehyde, protein carbonyl content and 8-hydroxy-2'-deoxyguanosine) were present in MDD patients. Specific modifications could be identified according to disease stages and clinical features. Interestingly, antidepressant treatment corrected these changes. Accordingly, in patients in remission from depression, oxidative stress markers were globally normalized. This narrative review suggests the particular interest of oxidative stress biomarkers for MDD care that may contribute to the heterogeneity of the disease and provide the opportunity to find new therapeutic targets.

Omega-3 Polyunsaturated Fatty Acids in Managing Comorbid Mood Disorders in Chronic Obstructive Pulmonary Disease (COPD): A Review

Chronic obstructive pulmonary disease (COPD) is the third-leading cause of mortality globally, significantly affecting people over 40 years old. COPD is often comorbid with mood disorders; however, they are frequently neglected or undiagnosed in COPD management, thus resulting in unintended treatment outcomes and higher mortality associated with the disease. Although the exact link between COPD and mood disorders remains to be ascertained, there is a broader opinion that inflammatory reactions in the lungs, blood, and inflammation-induced changes in the brain could orchestrate the onset of mood disorders in COPD. Although the current management of mood disorders such as depression in COPD involves using antidepressants, their use has been limited due to tolerability issues. On the other hand, as omega-3 polyunsaturated fatty acids (n-3 PUFAs) play a vital role in regulating inflammatory responses, they could be promising alternatives in managing mood disorders in COPD. This review discusses comorbid mood disorders in COPD as well as their influence on the progression and management of COPD. The underlying mechanisms of comorbid mood disorders in COPD will also be discussed, along with the potential role of n-3 PUFAs in managing these conditions.

Urine 3-Nitrotyrosine and Serum HDL as Potential Biomarkers of Depression

Depression (MDD) is a leading psychiatric entity worldwide, with a high impact on individual life and public health. In recent years, efforts have been made to elucidate its biological underpinnings. MDD biomarker research provides promise for a better understanding of the biochemical processes involved in its pathogenesis. Oxidative and nitrosative stress (O&NS) and lipid disturbances are reported as major factors favoring the occurrence of depression. A total of 29 patients with MDD and 30 healthy volunteers were examined using the Hamilton Depression Scale (HAM-D), the Hamilton Anxiety Scale (HAM-A), and the Beck Depression Inventory (BDI). Blood and urine were collected to search for potential MDD biomarkers. O&NS parameters and β-amyloid were assessed in the urine, while cholesterol fractions were assessed in the blood. The group of depressed patients was characterized by higher concentrations of urine superoxide dismutase (SOD), 3-nitrotyrosine (3-NT), catalase (CAT), reduced glutathione (GSH), tryptophan (TRY), and serum triglycerides (TGA), along with lower levels of serum high-density lipoprotein (HDL). Elevated urine 3-NT and decreased serum HDL, considered together, were found to have the greatest potential as markers of depression. The study supports the importance of oxidative stress and cholesterol disturbances in MDD. Further research is required to assess their clinical usefulness as markers.

Oxidative stress parameters and antioxidants in adults with unipolar or bipolar depression versus healthy controls: Systematic review and meta-analysis

BACKGROUND

To study differences in oxidative stress markers and antioxidants among patients with bipolar depression (BPD) and unipolar depression (UPD).

METHODS

Data sources. Electronic MEDLINE/PubMed/Cochrane Library/Scopus/TripDatabase database search until 30/06/2021.

STUDY SELECTION

Included were articles comparing antioxidant or oxidative stress markers between adults with BPD or UPD and healthy controls (HCs).

DATA EXTRACTION

Two authors extracted data independently. Random effects meta-analysis, calculating standardized mean differences for results from ≥3 studies.

RESULTS

Oxidative stress markers reported in 40 studies -1 published repeatedly- (UPD, studies = 30 n = 3072; their HCs, n = 2856; BPD, studies = 11 n = 393; their HCs, n = 540; with 1 study reporting on both UPD and BPD) included thiobarbituric acid reactive substances (TBARS), antioxidant uric acid and antioxidant-enhancing enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GPX). Compared with HCs, UPD and BPD were associated with significantly higher levels of TBARS, without differences between UPD and BPD (P = 0.11). Compared with HCs, UPD and BPD did not differ regarding the activity of the CAT (P = 0.28), SOD (P = 0.87) and GPX (P = 0.25) enzymes. However, uric acid levels were significantly higher vs HCs in BPD than in UPD among adult patients (P = 0.004). Results were heterogenous, which, for some parameters, decreased after stratification by the blood source (serum, plasma red blood cells, whole blood).

LIMITATIONS

The main limitations are the small number of studies/participants in the BPD subgroup, and heterogeneity of the results.

SUMMATIONS

Both BPD and UPD may be associated with an impaired oxidative stress balance, with significantly higher uric acid levels vs. HCs in UPD than in BPD.

Towards Tailored Gut Microbiome-Based and Dietary Interventions for Promoting the Development and Maintenance of a Healthy Brain

Mental health is determined by a complex interplay between the Neurological Exposome and the Human Genome. Multiple genetic and non-genetic (exposome) factors interact early in life, modulating the risk of developing the most common complex neurodevelopmental disorders (NDDs), with potential long-term consequences on health. To date, the understating of the precise etiology underpinning these neurological alterations, and their clinical management pose a challenge. The crucial role played by diet and gut microbiota in brain development and functioning would indicate that modulating the gut-brain axis may help protect against the onset and progression of mental-health disorders. Some nutritional deficiencies and gut microbiota alterations have been linked to NDDs, suggesting their potential pathogenic implications. In addition, certain dietary interventions have emerged as promising alternatives or adjuvant strategies for improving the management of particular NDDs, at least in particular subsets of subjects. The gut microbiota can be a key to mediating the effects of other exposome factors such as diet on mental health, and ongoing research in Psychiatry and Neuropediatrics is developing Precision Nutrition Models to classify subjects according to a diet response prediction based on specific individual features, including microbiome signatures. Here, we review current scientific evidence for the impact of early life environmental factors, including diet, on gut microbiota and neuro-development, emphasizing the potential long-term consequences on health; and also summarize the state of the art regarding the mechanisms underlying diet and gut microbiota influence on the brain-gut axis. Furthermore, we describe the evidence supporting the key role played by gut microbiota, diet and nutrition in neurodevelopment, as well as the effectiveness of certain dietary and microbiome-based interventions aimed at preventing or treating NDDs. Finally, we emphasize the need for further research to gain greater insight into the complex interplay between diet, gut microbiome and brain development. Such knowledge would help towards achieving tailored integrative treatments, including personalized nutrition.

Molecular correlates of mitochondrial dysfunctions in major depression: Evidence from clinical and rodent studies

Major depressive disorder (MDD) is one of the most prevalent stress-related mental disorders worldwide. Several biological mechanisms underlying the pathophysiology of MDD have been proposed, including endocrine disturbances, neurotransmitter deficits, impaired neuronal plasticity, and more recently, mitochondrial dysfunctions. In this review, we provide an overview of relevant molecular correlates of mitochondrial dysfunction in MDD, based on findings from clinical studies and stress-induced rodent models. We also compare differences and similarities between the phenotypes of MDD patients and animal models. Our analysis of the literature reveals that both MDD and stress are associated, in humans and animals, with changes in mitochondrial biogenesis, redox imbalance, increased oxidative damages of cellular macromolecules, and apoptosis. Yet, a considerable amount of conflicting data exist and therefore, the translation of findings from clinical and preclinical research to novel therapies for MDD remains complex. Further studies are needed to advance our understanding of the molecular networks and biological mechanisms involving mitochondria in the pathophysiology of MDD.

Elevated activity of plasma superoxide dismutase in never-treated first-episode schizophrenia patients: Associated with depressive symptoms

Oxidative stress in excess may be engaged in the pathophysiological development of schizophrenia (SCZ). Previous research showed altered activity of superoxide dismutase (SOD) in patients suffering from SCZ, with inconsistent results. However, few studies have analyzed the relationship between SOD activity and psychopathological symptoms in never-treated first-episode (NTFE) patients with SCZ. The activities of manganese SOD (MnSOD) and total SOD were measured in a large sample of 166 NTFE patients with SCZ, and 133 healthy controls. The patients' symptoms were evaluated by the Positive and Negative Syndrome Scale (PANSS), as well as the depressive and cognitive factors originated from the PANSS five-factor model. NTFE patients had significantly higher activities of MnSOD and total SOD than healthy controls (both p < 0.01). Correlation analysis displayed a notably positive correlation between both MnSOD or total SOD activities and the PANSS depressive factor, as well as between MnSOD activity and the PANSS general psychopathology subscale score (all p < 0.05). Stepwise multiple regression analysis revealed that both MnSOD and total SOD were independent factors affecting PANSS depressive factor and PANSS general psychopathology subscale score. Our findings suggest that increased SOD activity may be associated with comorbid depressive symptoms in NTFE patients with SCZ.

Neurotrophins, cytokines, oxidative stress mediators and mood state in bipolar disorder: systematic review and meta-analyses

BACKGROUND

A reliable biomarker signature for bipolar disorder sensitive to illness phase would be of considerable clinical benefit. Among circulating blood-derived markers there has been a significant amount of research into inflammatory markers, neurotrophins and oxidative stress markers.AimsTo synthesise and interpret existing evidence of inflammatory markers, neurotrophins and oxidative stress markers in bipolar disorder focusing on the mood phase of illness.

METHOD

Following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-analyses) guidelines, a systematic review was conducted for studies investigating peripheral biomarkers in bipolar disorder compared with healthy controls. We searched Medline, Embase, PsycINFO, SciELO and Web of Science, and separated studies by bipolar mood phase (mania, depression and euthymia). Extracted data on each biomarker in separate mood phases were synthesised using random-effects model meta-analyses.

RESULTS

In total, 53 studies were included, comprising 2467 cases and 2360 controls. Fourteen biomarkers were identified from meta-analyses of three or more studies. No biomarker differentiated mood phase in bipolar disorder individually. Biomarker meta-analyses suggest a combination of high-sensitivity C-reactive protein/interleukin-6, brain derived neurotrophic factor/tumour necrosis factor (TNF)-α and soluble TNF-α receptor 1 can differentiate specific mood phase in bipolar disorder. Several other biomarkers of interest were identified.

CONCLUSIONS

Combining biomarker results could differentiate individuals with bipolar disorder from healthy controls and indicate a specific mood-phase signature. Future research should seek to test these combinations of biomarkers in longitudinal studies.Declaration of interestNone.

The Omega-6:Omega-3 ratio: A critical appraisal and possible successor

The well-known health effects of the long-chain, marine omega-3 (n-3) fatty acids (FAs) has led to a growing interest in the prognostic value that blood levels of these FAs might have vis-à-vis cardiovascular and neurocognitive diseases. The measurement and expression of n-3 FA levels is not straight-forward, however, and a wide variety of means of expression of n-3 FA status have been used in research and clinical medicine. This has led to considerable confusion as to what "optimal" n-3 FA status is. The n-6:n-3 ratio has enjoyed relatively widespread use, but this apparently simple metric has both theoretical and practical difficulties that have contributed to misunderstandings in this field. Just as the once-popular polyunsaturated:saturated FA ratio has largely disappeared from the nutritional and medical literature, it may be time to replace the n-6:n-3 ratio with a newer metric that focuses on the primary deficiency in Western diets - the lack of eicosapentaenoic and docosahexaenoic acids (EPA and DHA). The Omega-3 Index (red blood cell EPA+DHA) has much to recommend it in this regard.

In vivo imaging of oxidative stress and fronto-limbic white matter integrity in young adults with mood disorders

Fronto-limbic connectivity is compromised in mood disorders, as reflected by impairments in white matter (WM) integrity revealed by diffusion tensor imaging. Although the underlying mechanisms remain unclear, disruption to normal myelination due to oxidative stress is thought to play a key role. We aimed to determine whether fronto-limbic WM integrity is compromised, and associated with in vivo antioxidant levels (indexed by glutathione; GSH), in young adults with unipolar depression (DEP) and bipolar (BD) disorders. Ninety-four patients with DEP, 76 with BD and 59 healthy controls (18-30 years) underwent diffusion tensor and proton magnetic resonance spectroscopy imaging. Fractional anisotropy (FA) was calculated from the cingulum bundle (cingulate, hippocampus), fornix, stria terminalis (ST) and uncinate fasciculus tracts. GSH concentration was measured in anterior cingulate cortex (ACC) and hippocampus (HIPP). Compared to controls, DEP showed significantly reduced FA in ST, whereas BD did not significantly differ in FA across the five tracts. There were significant positive correlations between ST-FA and HIPP-GSH across groups. Regression analysis revealed that having DEP or BD and reduced HIPP-GSH were significantly associated with reduced ST-FA. Similarly, decreased ST-FA was associated with poorer neuropsychological performance in conjunction with having DEP. Our findings suggest a structural disconnectivity specific to the limbic region of young adults with DEP. Decreased WM integrity was associated with depleted levels of hippocampal GSH suggesting that this particular disruption may be linked to oxidative stress at early stages of illness. Young adults with BD do not have the same degree of impairment.

Natural regulatory IgM-mediated autoimmune responses directed against malondialdehyde regulate oxidative and nitrosative pathways and coupled with IgM responses to nitroso adducts attenuate depressive and physiosomatic symptoms at the end of term pregnancy

AIM

We aimed to delineate the effects of immunoglobulin (Ig)M-mediated autoimmune responses directed against malondialdehyde (MDA) and nitroso (SNO) adducts on nitro-oxidative stress and depressive and physiosomatic symptoms (DPSS) at the end of term.

METHODS

IgM responses to MDA, NO (nitroso) adducts formed by nitrosylation, and NO₂ tyrosine formed by nitration were measured as well as hydroperoxides (ferrous oxidation xylenol orange), advanced protein oxidation products (AOPP), and NO metabolite (NOx) levels in women at the end of term pregnancy and in normal controls.

RESULTS

IgM responses to MDA were significantly and inversely associated with AOPP, ferrous oxidation xylenol orange, and NOx and DPSS. IgM responses to NO adducts were significantly and inversely associated with DPSS and positively with NOx levels. There were significant associations between IgM responses to MDA, NO adducts, and NO₂ tyrosine. The DPSS score was predicted by AOPP and a lifetime history of premenstrual syndrome (both positively) and IgM responses to NO adducts (inversely). Furthermore, 71.8% of the variance in the index of nitro-oxidative stress was explained by lowered IgM responses to MDA, antioxidant levels (zinc, total radical trapping parameter), and inflammatory mediators.

CONCLUSION

Lowered levels of IgM responses to MDA during pregnancy are accompanied by a reduced regulation of nitro-oxidative processes thereby explaining increased oxidative and nitrosative stress biomarkers in association with DPSS. IgM responses to NO adducts, which reflect nitrosylation as a consequence of increased NO production, regulate DPSS symptoms at the end of term and are a trait marker of major depression. IgM responses to MDA are a key part of the compensatory anti-inflammatory responses system.

Cognitive Impairment Is Associated with a Low Omega-3 Index in the Elderly: Results from the KORA-Age Study

BACKGROUND

Omega-3 polyunsaturated fatty acids (PUFA) may affect the risk of cognitive decline in older adults.

METHODS

Cross-sectional analysis was conducted among 720 (50.4% women) participants aged 68-92 years (mean age: 77.6, SD ±6.2) of the population-based KORA-Age study. Eicosapentaenoic acid and docosahexaenoic acid (omega-3 index) were measured in erythrocytes as a percentage of total fatty acids. The categories low (<5.7), intermediate (5.7-6.8), and high (>6.8) levels of the omega-3 index were built using tertiles. The association between cognitive status and omega-3 levels was assessed by logistic regression analyses with adjustments for important concurrent risk factors of cognitive decline.

RESULTS

In the sex- and age-adjusted model (model 1), subjects with a low omega-3 index were at a significantly higher risk for cognitive impairment (OR: 1.77, 95% CI: 1.15-2.73, p = 0.009). This association remained stable after further adjusting for educational level (model 2; OR: 1.75, 95% CI: 1.13-2.71, p = 0.01) and metabolic risk factors (model 3; OR: 1.77, 95% CI: 1.14-2.75, p = 0.01). After further controlling for affective disorders (model 4), the association did not attenuate (OR: 1.77, 95% CI: 1.14-2.76, p = 0.01).

CONCLUSION

A robust association was found between low omega-3 levels and cognitive impairment in an elderly population. Further research is needed to understand the link between omega-3 PUFA and cognitive functioning.

Oxidative stress predicts depressive symptom changes with omega-3 fatty acid treatment in coronary artery disease patients

BACKGROUND

Antidepressant efficacy of omega-3 polyunsaturated fatty acid (n-3 PUFA) treatment in coronary artery disease (CAD) patients remains unpredictable. N-3 PUFA can mitigate oxidative stress, which is common in CAD and may contribute to depressive symptoms. This study investigated whether greater pre-treatment oxidative stress, measured by the ratios of late-stage lipid peroxidation markers (malondialdehyde [MDA], 4-hydroxy-2-nonenal [4-HNE], and 8-isoprostane [8-ISO]) to an early-stage marker (lipid hydroperoxides [LPH]), predicted n-3 PUFA antidepressant benefits in CAD.

METHODS

This was a secondary analysis of CAROTID (CAD Randomized Omega-3 Trial in Depression, NCT00981383). Patient demographics and medical characteristics were collected. Depressive symptoms were measured using the 17-item Hamilton Depression Rating Scale (HAM-D). Patients were then randomized to receive either 1.9g/day n-3 PUFA or placebo for 12weeks, after which HAM-D scores were reassessed. Baseline LPH, 4-HNE, 8-ISO, MDA and n-3 PUFA concentrations were analysed from fasting blood.

RESULTS

Seventy-nine patients (age=61.1±8.5, 76% male, HAM-D=7.5±6.1) were included (n=45 placebo, n=34 n-3 PUFA). In the n-3 PUFA group, higher baseline ratios of MDA/LPH (primary analysis: F_1,33=6.20, beta=-0.35, p=0.018), 4-HNE/LPH (exploratory analysis: F_1,33=5.35, beta=-0.32, p=0.027), and 8-ISO/LPH (exploratory analysis: F_1,33=6.10, beta=-0.33, p=0.019), indicating higher oxidative stress, were associated with greater depressive symptom improvement. In each model, higher baseline EPA+DHA concentrations independently predicted depressive symptom improvement with n-3 PUFA (MDA/LPH: F_1,33=11.05, p=0.002; 4-HNE/LPH: F_1,33=11.36, p=0.002; 8-ISO/LPH: F_1,33=13.15, p=0.001). No associations were observed in the placebo group.

CONCLUSIONS

n-3 PUFA may be more likely to improve depressive symptoms in CAD patients with pre-treatment evidence of oxidative stress.

Polyunsaturated fatty acids and recurrent mood disorders: Phenomenology, mechanisms, and clinical application

A body of evidence has implicated dietary deficiency in omega-3 polyunsaturated fatty acids (n-3 PUFA), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in the pathophysiology and etiology of recurrent mood disorders including major depressive disorder (MDD) and bipolar disorder. Cross-national and cross-sectional evidence suggests that greater habitual intake of n-3 PUFA is associated with reduced risk for developing mood symptoms. Meta-analyses provide strong evidence that patients with mood disorders exhibit low blood n-3 PUFA levels which are associated with increased risk for the initial development of mood symptoms in response to inflammation. While the etiology of this n-3 PUFA deficit may be multifactorial, n-3 PUFA supplementation is sufficient to correct this deficit and may also have antidepressant effects. Rodent studies suggest that n-3 PUFA deficiency during perinatal development can recapitulate key neuropathological, neurochemical, and behavioral features associated with mood disorders. Clinical neuroimaging studies suggest that low n-3 PUFA biostatus is associated with abnormalities in cortical structure and function also observed in mood disorders. Collectively, these findings implicate dietary n-3 PUFA insufficiency, particularly during development, in the pathophysiology of mood dysregulation, and support implementation of routine screening for and treatment of n-3 PUFA deficiency in patients with mood disorders.

A meta-analysis of blood cytokine network alterations in psychiatric patients: comparisons between schizophrenia, bipolar disorder and depression

Schizophrenia, bipolar disorder and major depressive disorder (MDD) have all been associated with aberrant blood cytokine levels; however, neither the pattern of cytokine alterations nor the impact of clinical status have been compared across disorders. We performed a meta-analysis of blood cytokines in acutely and chronically ill patients with these major psychiatric disorders. Articles were identified by searching the PubMed, PsycInfo and Web of Science, and the reference lists of these studies. Sixty-eight studies met the inclusion criteria (40 schizophrenia, 10 bipolar disorder and 18 MDD) for acutely ill patients. Forty-six studies met the inclusion criteria (18 schizophrenia, 16 bipolar disorder and 12 MDD) for chronically ill patients. Levels of two cytokines (interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)), one soluble cytokine receptor (sIL-2R), and one cytokine receptor antagonist (IL-1RA) were significantly increased in acutely ill patients with schizophrenia, bipolar mania and MDD compared with controls (P<0.01). Following treatment of the acute illness, IL-6 levels significantly decreased in both schizophrenia and MDD (P<0.01); sIL-2R levels increased in schizophrenia; and IL-1RA levels in bipolar mania decreased. In chronically ill patients, the levels of IL-6 were significantly increased in schizophrenia, euthymic (but not depressed) bipolar disorder and MDD compared with controls (P<0.01). The levels of IL-1β and sIL-2R were significantly increased in both chronic schizophrenia and euthymic bipolar disorder. Overall, there were similarities in the pattern of cytokine alterations in schizophrenia, bipolar disorder and MDD during acute and chronic phases of illness, raising the possibility of common underlying pathways for immune dysfunction. Effects of treatment on cytokines were more robust for schizophrenia and MDD, but were more frequently studied than for acute mania. These findings have important implications for our understanding of the pathophysiology and treatment of major psychiatric disorders.

Fatty acids composition of Caenorhabditis elegans using accurate mass GCMS-QTOF

The free living nematode Caenorhabditis elegans is a proven model organism for lipid metabolism research. Total lipids of C. elegans were extracted using chloroform and methanol in 2:1 ratio (v/v). Fatty acids composition of the extracted total lipids was converted to their corresponding fatty acids methyl esters (FAMEs) and analyzed by gas chromatography/accurate mass quadrupole time of flight mass spectrometry using both electron ionization and chemical ionization techniques. Twenty-eight fatty acids consisting of 12 to 22 carbon atoms were identified, 65% of them were unsaturated. Fatty acids containing 12 to17 carbons were mostly saturated with stearic acid (18:0) as the major constituent. Several branched-chain fatty acids were identified. Methyl-14-methylhexadecanoate (iso- 17:0) was the major identified branched fatty acid. This is the first report to detect the intact molecular parent ions of the identified fatty acids in C. elegans using chemical ionization compared to electron ionization which produced fragmentations of the FAMEs.

Role of Omega-3 Fatty Acids in the Etiology, Treatment, and Prevention of Depression: Current Status and Future Directions

Over the past three decades a body of translational evidence has implicated dietary deficiency in long-chain omega-3 (LCn-3) fatty acids, including eicosapenaenoic acid (EPA) and docosahexaenoic acid (DHA), in the pathophysiology and etiology of major depressive disorder (MDD). Cross-national and cross-sectional data suggest that greater habitual intake of preformed EPA+DHA is associated with reduced risk for developing depressive symptoms and syndromal MDD. Erythrocyte EPA and DHA composition is highly correlated with habitual fish or fish oil intake, and case-control studies have consistently observed lower erythrocyte EPA and/or DHA levels in patients with MDD. Low erythrocyte EPA+DHA composition may also be associated with increased risk for suicide and cardiovascular disease, two primary causes of excess premature mortality in MDD. While controversial, dietary EPA+DHA supplementation may have antidepressant properties and may augment the therapeutic efficacy of antidepressant medications. Neuroimaging and rodent neurodevelopmental studies further suggest that low LCn-3 fatty acid intake or biostatus can recapitulate central pathophysiological features associated with MDD. Prospective findings suggest that low LCn-3 fatty acid biostatus increases risk for depressive symptoms in part by augmenting pro-inflammatory responsivity. When taken collectively, these translational findings provide a strong empirical foundation in support of dietary LCn-3 fatty acid deficiency as a modifiable risk factor for MDD. This review provides an overview of this translational evidence and then discusses future directions including strategies to translate this evidence into routine clinical screening and treatment algorithms.

Effect of Selenium Deficiency on Nitric Oxide and Heat Shock Proteins in Chicken Erythrocytes

Selenium (Se) deficiency induces various types of diseases, including hemolytic anemia, which is one of the basic pathologies of erythrocyte damage. To investigate the effect of Se deficiency on chicken erythrocytes, we detected the effects of Se deficiency on the nitric oxide (NO) content and the levels of heat shock proteins (Hsps) in chicken erythrocytes, including Hsp27, Hsp40, Hsp60, Hsp70, and Hsp90. One-day-old chickens (180) were randomly divided into two groups, a low-Se group (L group, fed with a 0.008 mg/kg Se diet) and a control group (C group, fed with a 0.2 mg/kg Se diet). Next, erythrocytes were collected at 35 days old, and the NO content, activity of inducible nitric oxide synthase (iNOS), and levels of Hsps (27, 40, 60, 70, and 90) were examined. Compared with the C group, the NO and iNOS levels were significantly higher (P < 0.05), and the Hsps in the mRNA and protein levels were generally higher (P < 0.05) in the L group. Meanwhile, the correlation analysis showed that there were positive correlations between Hsps and NO. Thus, as typical damage biomarkers, NO and Hsps may play special roles in chicken erythrocyte injury by Se deficiency.

Cross-sectional association between serum concentrations of n-3 long-chain PUFA and depressive symptoms: results in Japanese community dwellers

The effect of n-3 long-chain PUFA (n-3 LCPUFA) on depression in healthy subjects is unclear, and most of the previous studies have focused on populations eating Western diets with lower fish intake. The present study investigated the association between blood levels of n-3 LCPUFA and depressive symptoms in Japanese community dwellers with higher n-3 LCPUFA blood levels. A cross-sectional study was conducted from 2006 to 2008, including 1050 men and 1073 women aged 40 years or older from the National Institute for Longevity Sciences – the Longitudinal Study of Aging. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depressive symptoms. Multiple logistic regression analysis was performed to estimate the OR and 95 % CI for a CES-D score ≥16. Serum concentrations of n-3 PUFA, but not n-6 PUFA, were inversely associated with depressive symptoms. Compared with the lowest quintile, the adjusted OR for serum EPA at the fourth and fifth quintiles were 0·55 (95 % CI 0·35, 0·85) and 0·64 (95 % CI 0·42, 0·98), respectively, and at the fifth quintile for DHA it was 0·58 (95 % CI 0·37, 0·92), for the presence of depressive symptoms (P_{for trend}=0·013 and 0·011, respectively). Serum levels of EPA and DHA were inversely associated with depressive symptoms in Japanese community dwellers with higher blood levels of n-3 LCPUFA, suggesting that n-3 LCPUFA intakes corresponding to higher levels in a Japanese population may have implications for a lower prevalence of depression.

Erythrocyte fatty acid profiles and plasma homocysteine, folate and vitamin B6 and B12 in recurrent depression: Implications for co-morbidity with cardiovascular disease

Oxidative stress induced interactions between fatty acid (FA) and one-carbon metabolism may be involved in co-occurrence of major depressive disorder (MDD) and cardiovascular disease (CVD), which have been scarcely studied together. In 137 recurrent MDD-patients vs. 73 age- and sex-matched healthy controls, we simultaneously measured key components of one-carbon metabolism in plasma (homocysteine, folate, vitamins B6 and B12), and of FA-metabolism in red blood cell membranes [main polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA) and structural FA-indices (chain length, unsaturation, peroxidation)]. Results show significant positive associations of folate with EPA, DHA, and the peroxidation index, which were similar in patients and controls. After correction for confounders, these associations were lost except for EPA. Associations between B-vitamins and FA-parameters were non-significant, but also similar in patients and controls. Homocysteine and DHA were significantly less negatively associated in patients than in controls. In conclusion, these data indicate similarities but also differences in associations between parameters of one-carbon and FA-metabolism in recurrent MDD patients vs. controls, which may reflect differences in handling of oxidative stress. Further research should test the consequences of these differences, particularly the premature development of CVD in MDD.

A review of recent evidence in human studies of n-3 and n-6 PUFA intake on cardiovascular disease, cancer, and depressive disorders: does the ratio really matter?

Polyunsaturated fatty acids (PUFAs) have been considered of great interest for human health due to their potential anti-inflammatory action that may protect from a number of chronic-degenerative diseases with an inflammatory pathogenesis. This review aimed to report the most updated evidence of both n-3 and n-6 PUFAs effect on cardiovascular disease, cancer, and depression in humans. Attention has been also paid to those studies exploring the effects of the ratio intake. Results from pooled analyses of human studies reported a general positive effect of n-3 PUFAs intake on all outcomes considered. In contrast, the role of n-6 PUFAs on human health needs to be better assessed in order to clearly identify which compound exerts beneficial/harmful effects. Only a limited number of clinical studies considered the n-3:n-6 PUFAs ratio, rather reporting contrasting results. A number of limitations when considering the ratio between these two families of PUFAs have risen.

Red blood cell fatty acids and biomarkers of inflammation: a cross-sectional study in a community-based cohort

INTRODUCTION

Inflammation and inflammatory biomarkers have emerged as integral components and predictors of incident cardiovascular (CV) disease. Omega-3 fatty acids, particularly eicosapentaenoic and docosahexaenoic acids (EPA and DHA) have anti-inflammatory properties, and have been variably associated with lower blood pressure, favorable blood lipid changes, and reduced CV events.

METHODS AND RESULTS

We examined the cross-sectional association of red blood cell (RBC) fatty acids, representative of body membrane fatty acid composition, with 10 biomarkers active in multiple inflammatory pathways in 2724 participants (mean age 66 ± 9 years, 54% women, 8% minorities) from the Framingham Offspring and minority Omni Cohorts. After multivariable adjustment, the RBC EPA and DHA content was inversely correlated (all P ≤ 0.001) with 8 biomarkers: urinary isoprostanes (r = -0.16); and soluble interleukin-6 (r = -0.10); C-reactive protein (r = -0.08); tumor necrosis factor receptor 2 (r = -0.08); intercellular adhesion molecule-1 (r = -0.08); P-selectin (r = -0.06); lipoprotein-associated phospholipase-A2 mass (r = -0.11) and activity (r = -0.08). The correlations for monocyte chemoattractant protein-1 was -0.05, P = 0.006 and osteoprotegerin (r = -0.06, P = 0.002) were only nominally significant.

CONCLUSION

In our large community-based study, we observed modest inverse associations between several types of inflammatory biomarkers with RBC omega-3 fatty acid levels. Our findings are consistent with the hypothesis that omega-3 fatty acids have anti-inflammatory properties.

Supplementation of n-3 Polyunsaturated Fatty Acids for Major Depressive Disorder: A Randomized, Double-Blind, 12-Week, Placebo-Controlled Trial in Korea

BACKGROUND

Controversy over the efficacy of n-3 polyunsaturated fatty acids (PUFAs) in depression continues to this day. The present study investigated the hypothesis that n-3 PUFA supplementation reduces depressive symptoms in Korean patients with major depressive disorder.

METHODS

In a randomized, double-blind, placebo-controlled, 12-week, parallel-group trial, 35 patients with Center for Epidemiological Studies Depression Scale Korean version (CES-D-K) scores ≥25 and depression confirmed by a psychiatrist were assigned to take either 3 capsules of n-3 PUFAs (1,140 mg of EPA + 600 mg of DHA; n = 18) or placebo (olive oil + safflower oil; n = 17).

RESULTS

Supplementation with n-3 PUFAs significantly reduced Clinical Global Impression Improvement (CGI-I) scores as compared with intake of placebo using intention-to-treat analysis with last-observation-carried-forward after adjusting for energy, fat, and fish intake. However, the CES-D-K, Hamilton Depression Rating Scale-17, and Clinical Global Impression Scale scores did not significantly differ between the n-3 PUFA and placebo groups. After supplementation with n-3 PUFAs, the erythrocyte levels of n-3 PUFAs were significantly increased, but n-6 PUFA levels were decreased.

CONCLUSIONS

n-3 PUFAs demonstrated an advantage over placebo that did not reach clinical significance, although CGI-I score was significantly decreased in the n-3 PUFA group as compared with the placebo group.

A meta-analysis of lipid peroxidation markers in major depression

BACKGROUND

Major depressive disorder (MDD) may be associated with oxidative damage to lipids, which can potentially affect mood-regulating pathways. This meta-analysis summarizes current knowledge regarding lipid peroxidation markers in clinical samples of MDD and the effects of antidepressant pharmacotherapy on those markers.

METHODS

MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Collaboration were searched for original, peer-reviewed articles measuring markers of lipid peroxidation in patients with MDD and nondepressed healthy controls up to April 2015. Standardized mean differences (SMDs) were generated from random effects models summarizing mean (± standard deviations) concentrations of selected markers.

RESULTS

Lipid peroxidation was greater in MDD than in controls (studies =17, N=857 MDD/782 control, SMD =0.83 [0.56-1.09], z=6.11, P<0.01, I (2)=84.0%) and was correlated with greater depressive symptom severity (B=0.05, df=8, P<0.01). Antidepressant treatment was associated with a reduction in lipid peroxidation in MDD patients (studies=5, N=222, SMD=0.71 [0.40-0.97], P<0.01; I (2)=42.5%).

LIMITATIONS

Lipid peroxidation markers were sampled from peripheral blood, included studies comparing MDD to controls were all cross-sectional, and only five antidepressant treatment studies were eligible for inclusion.

CONCLUSION

Increased lipid peroxidation was associated with MDD and may be normalized by antidepressants. Continued investigation of lipid peroxidation in MDD is warranted.

Construction and analysis of correlation networks based on gas chromatography-mass spectrometry metabonomics data for lipopolysaccharide-induced inflammation and intervention with volatile oil from Angelica sinensis in rats

Angelica sinensis (AS) is a well-known important traditional Chinese medicine that yields a volatile oil with anti-inflammatory effects.

Serum oxidative stress, visfatin and apelin in healthy women and those with premenstrual syndrome

The aim of this study was to investigate whether there is a relationship between premenstrual syndrome and oxidative stress, visfatin and apelin. The study included 40 women with premenstrual syndrome and 40 healthy women. In all subjects, serum visfatin, apelin and oxidative stress parameters were studied in venous blood samples. The oxidative stress parameters were higher in the premenstrual syndrome group than among the controls, but this difference did not reach statistical significance (p > 0.05). It was found that total antioxidant capacity was similar in both groups. For the insulin-serotonin cycle markers, no significant difference was found between groups in terms of visfatin level (p = 0.893), although apelin was found to be significantly higher in the premenstrual syndrome group when compared with the controls (p < 0.001). According to our results, apelin can be used as an ancillary laboratory test in the diagnosis of premenstrual syndrome.