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

A Metabolome-Wide Mendelian Randomization Study Identifies Dysregulated Arachidonic Acid Synthesis as a Potential Causal Risk Factor for Bipolar Disorder

BACKGROUND

Bipolar disorder (BPD) is a debilitating mood disorder with an unclear etiology. A better understanding of the underlying pathophysiological mechanisms will help to identify novel targets for improved treatment options and prevention strategies. In this metabolome-wide Mendelian randomization study, we screened for metabolites that may have a causal role in BPD.

METHODS

We tested a total of 913 circulating metabolite exposures assessed in 14,296 Europeans using a mass spectrometry-based platform. For the BPD outcome, we used summary data from the largest and most recent genome-wide association study reported to date, including 41,917 BPD cases.

RESULTS

We identified 33 metabolites associated with BPD (padjusted < 5.48 × 10-5). Most of them were lipids, including arachidonic acid (β = -0.154, SE = 0.023, p = 3.30 × 10-11), a polyunsaturated omega-6 fatty acid, along with several complex lipids containing either an arachidonic or a linoleic fatty acid side chain. These associations did not extend to other closely related psychiatric disorders like schizophrenia or depression, although they may be involved in the regulation of lithium response. These lipid associations were driven by genetic variants within the FADS1/2/3 gene cluster, which is a robust BPD risk locus encoding a family of fatty acid desaturase enzymes that are responsible for catalyzing the conversion of linoleic acid into arachidonic acid. Statistical colocalization analyses indicated that 27 of the 33 metabolites shared the same genetic etiology with BPD at the FADS1/2/3 cluster, demonstrating that our findings are not confounded by linkage disequilibrium.

CONCLUSIONS

Overall, our findings support the notion that arachidonic acid and other polyunsaturated fatty acids may represent potential targets for BPD.

Comparative Efficacy of Omega-3 Fatty Acid with Other Interventions for Depression in Children and Adolescents: A Systematic Review and Network Meta-Analysis

Background: The administration of omega-3 polyunsaturated fatty acid supplements is recommended as an adjuvant therapy for adults diagnosed with major depressive disorder. The evaluation of replicated data in combination treatment with omega-3 has been extensively conducted in adults over the past decade. However, the generalizability of these findings to pediatric groups is still uncertain. The objectives of this evaluation were twofold: (1) to evaluate the effectiveness of omega-3 and associated combination therapies in reducing the severity of depressive symptoms, and (2) to include remission rates (i.e., reduction of more than 50% in depression symptoms) as a measure of therapeutic efficacy. Methods: We conducted a literature search on PubMed/EMBASE from inception to October 2023. Data analyses were conducted using Stata (version 17.0). Results: We identified a total of 3168 articles. After eligibility screening of identified studies, nine studies (n = 561 participants) were included in our analysis herein. Pairwise comparisons revealed no significant improvement in depression symptoms for any intervention versus placebo. However, a clustered ranking plot identified omega-3 plus inositol as the most effective treatment for pediatric depression (77.3% efficacy). Omega-3 paired with psychoeducational psychotherapy significantly lowered the remission rate compared to placebo (standardized mean difference = 0.44, 95% confidence interval: 0.00-0.87, p = 0.048), resulting in a 91.5% remission rate, making it the most effective treatment in the study. Conclusions: Taken together, this network meta-analysis presents compelling evidence supporting the antidepressant effects of omega-3 in pediatric groups with depression. Future research should aim to investigate omega-3 as monotherapy for young individuals with depression, as well as investigate the efficacy of omega-3 in comparison to psychosocial interventions for affected individuals.

Mental health in society's margins: poor n-3 PUFA intake and psychological well-being of homeless youth

Dietary intake of long-chain n-3 PUFA (n-3 PUFA), particularly EPA and DHA, has been associated with psychological well-being, but little is known about the n-3 PUFA intake of homeless youth. The current study determined the association between depression and anxiety symptoms and n-3 PUFA intake and erythrocytes status in homeless youth. Totally, 114 homeless youth aged 18-24 years were recruited from a drop-in centre. n-3 PUFA dietary intake was assessed using an FFQ, and erythrocytes status was determined by gas chromatography (GC). Linear regression models were used to determine the relationship between psychological well-being and n-3 PUFA intake and status. The mean intakes of EPA and DHA for all participants (0·06 ± 0·13 g/d and 0·11 ± 0·24 g/d) were well below recommended levels, and mean erythrocytes EPA + DHA (n-3 index) in the cohort (2·42 %) was lower than reported for healthy, housed adolescents and those with clinical depression. There was no association of n-3 PUFA intake and erythrocytes status with either depression or anxiety. However, the relationships of depression with dietary EPA (P = 0·017) and DHA (P = 0·008), as well as erythrocytes DHA (P = 0·007) and n 3-index (P = 0·009), were significantly moderated by sex even after adjusting for confounders. Specifically, among females, as the intake and status of these n-3 PUFA decreased, depression increased. Our findings show poor dietary intake and low erythrocytes status of n-3 PUFA among homeless youth, which is associated with depressive symptoms among females.

A mitochondrial nexus in major depressive disorder: Integration with the psycho-immune-neuroendocrine network

Nervous system processes, including cognition and affective state, fundamentally rely on mitochondria. Impaired mitochondrial function is evident in major depressive disorder (MDD), reflecting cumulative detrimental influences of both extrinsic and intrinsic stressors, genetic predisposition, and mutation. Glucocorticoid 'stress' pathways converge on mitochondria; oxidative and nitrosative stresses in MDD are largely mitochondrial in origin; both initiate cascades promoting mitochondrial DNA (mtDNA) damage with disruptions to mitochondrial biogenesis and tryptophan catabolism. Mitochondrial dysfunction facilitates proinflammatory dysbiosis while directly triggering immuno-inflammatory activation via released mtDNA, mitochondrial lipids and mitochondria associated membranes (MAMs), further disrupting mitochondrial function and mitochondrial quality control, promoting the accumulation of abnormal mitochondria (confirmed in autopsy studies). Established and putative mechanisms highlight a mitochondrial nexus within the psycho-immune neuroendocrine (PINE) network implicated in MDD. Whether lowering neuronal resilience and thresholds for disease, or linking mechanistic nodes within the MDD pathogenic network, impaired mitochondrial function emerges as an important risk, a functional biomarker, providing a therapeutic target in MDD. Several treatment modalities have been demonstrated to reset mitochondrial function, which could benefit those with MDD.

Sex differences in erythrocyte fatty acid composition of first-diagnosed, drug-naïve patients with major depressive disorders

Background: Since depression, sex hormones, and fatty acid status are interrelated, it is important to understand their relationships. In this study, we aimed to investigate sex differences in erythrocyte membrane fatty acid composition among first-diagnosed, drug-naïve patients with major depressive disorders. Methods: The study included 139 individuals with first-diagnosed, drug-naïve depression (male/female = 48/91) and 55 healthy controls (male/female = 24/31). The levels of erythrocyte membrane fatty acids were analyzed to compare the difference between males and females in both patients with depression and healthy controls, as well as to study their correlation with depressive symptoms. Results: In first-diagnosed, drug-naïve patients with major depressive disorders, sex disparities were observed in the levels of erythrocyte saturated fatty acids (SFAs) and n-6 PUFAs (such as C18:0, C20:4n6 and C22:4n6), where higher levels evident in females compared to in males. We found a noteworthy correlation between fatty acid levels and depressive symptoms, in which there is a significant association between female patients and depression but a weaker association between male patients and depression. Conclusion: Our findings demonstrate higher levels of n-6 PUFAs and SFAs in female patients with depression. The relationship between fatty acid composition and depressive symptoms was more prominent in females than males. These findings highlight the significance of considering sex as a crucial and interconnected factor in future investigations and potential adjunctive treatment for mood disorders by targeting fatty acid metabolism.

New Insights into Prospective Health Potential of ω-3 PUFAs

PURPOSE OF REVIEW

Docosahexaenoic acid and eicosapentaenoic acid are the two essential long-chain ω-3 polyunsaturated fatty acids (ω-3 PUFAs) promoting human health which are obtained from diet or supplementation. The eicosanoids derived from ω-6 and ω-3 PUFAs have opposite characteristics of pro- and anti-inflammatory activities. The proinflammatory effects of ω-6 PUFAs are behind the pathology of the adverse health conditions of PUFA metabolism like cardiovascular diseases, neurological disorders, and inflammatory diseases. A balanced ω-6 to ω-3 ratio of 1-4:1 is critical to prevent the associated disorders. But due to modern agricultural practices, there is a disastrous shift in this ratio to 10-20:1. This review primarily aims to discuss the myriad health potentials of ω-3 PUFAs uncovered through recent research. It further manifests the importance of maintaining a balanced ω-6 to ω-3 PUFA ratio.

RECENT FINDINGS

ω-3 PUFAs exhibit protective effects against diabetes mellitus-associated complications including diabetic retinopathy, diabetic nephropathy, and proteinuria. COVID-19 is also not an exception to the health benefits of ω-3 PUFAs. Supplementation of ω-3 PUFAs improved the respiratory and clinical symptoms in COVID-19 patients. ω-3 PUFAs exhibit a variety of health benefits including anti-inflammatory property and antimicrobial property and are effective in protecting against various health conditions like atherosclerosis, cardiovascular diseases, diabetes mellitus, COVID-19, and neurological disorders. In the present review, various health potentials of ω-3 PUFAs are extensively reviewed and summarized. Further, the importance of a balanced ω-6 to ω-3 PUFA ratio has been emphasized besides stating the diverse sources of ω-3 PUFA.

Disturbances of phosphatidylcholines metabolism in major depressive disorder

OBJECTIVE

Major depressive disorder (MDD) is a common neuropsychiatry disorder with high prevalence and recurrence rate, but the misdiagnosis rate is inevitable due to the shortage of objective laboratory-based diagnostic criteria. This study is focused on the disturbance of lipid metabolism, providing potential biomarkers for diagnosing.

METHODS

Lipid metabolism-related molecules in plasma of 42 drug-naïve MDD patients and 49 healthy people were measured by liquid chromatography-mass spectrometry. Further to evaluate the diagnostic values of changed metabolites, these molecules were evaluated by the receiver operating characteristic curve. Based on the significant role of phosphatidylcholine (PC) disturbance in depression, oxidization of PCs, oxidation of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (OxPAPC), IL-8 and caspase-3 in hippocampus, and serum of chronic lipopolysaccharide (cLPS) depression mice were detected by ELISA.

RESULTS

Compared with healthy control, MDD patients expressed higher 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (16:0-16:0 PC, DPPC), 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (16:0-20:4 PC, PAPC), 1-palmitoyl-2-stearoyl-sn-glycero-3-phosphocholine (16:0-18:0 PC), glycocholic acid, taurocholic acid, glycoursodeoxycholic acid, and chenodeoxycholic acid glycine conjugate, and lower 1-heptadecanoyl-2-hydroxy-sn-glycero-3-phosphocholine (LPC 20:0). The 16:0-20:4 PC showed the great diagnostic value for MDD with an area under the curve (AUC) of 0.9519, and combination of 16:0 PC, 16:0-18:0 PC, and 16:0-20:4 PC exhibited the highest diagnostic value with AUC of 0.9602. OxPAPC was certified increase in hippocampus and serum of cLPS depression mice, which further supported PCs disorder participated in depression.

CONCLUSION

This research offers 16:0-20:4 PC as the latent diagnostic indicator for MDD and hints the important role of PCs in depression.

Lipids in major depressive disorder: new kids on the block or old friends revisited?

Major depressive disorder (MDD) is a psychiatric mood disorder that results in substantial functional impairment and is characterized by symptoms such as depressed mood, diminished interest, impaired cognitive function, and vegetative symptoms such as disturbed sleep. Although the exact etiology of MDD is unclear, several underlying mechanisms (disturbances in immune response and/or stress response) have been associated with its development, with no single mechanism able to account for all aspects of the disorder. Currently, about 1 in 3 patients are resistant to current antidepressant therapies. Providing an alternative perspective on MDD could therefore pave the way for new, unexplored diagnostic and therapeutic solutions. The central nervous system harbors an enormous pool of lipids and lipid intermediates that have been linked to a plethora of its physiological functions. The aim of this review is therefore to provide an overview of the implications of lipids in MDD and highlight certain MDD-related underlying mechanisms that involve lipids and/or their intermediates. Furthermore, we will also focus on the bidirectional relationship between MDD and the lipid-related disorders obesity and type 2 diabetes.

Integration of non-targeted metabolomics with network pharmacology deciphers the anxiolytic mechanisms of Platycladi Semen extracts in CUMS mice

ETHNOPHARMACOLOGICAL RELEVANCE

Platycladi Semen was recorded in Shen Nong's Herbal Classic and was considered a herbal medicine with low toxicity after long-term medication. Multiple traditional Chinese medicine prescriptions containing Platycladi Semen have been used to treat insomnia. Modern clinical practitioners commonly use Platycladi Semen to treat anxiety disorders, but there are few studies on its composition and anxiolytic mechanisms.

AIM OF THE STUDY

To describe the main components of Platycladi Semen and investigate its anxiolytic effects and mechanisms.

MATERIALS AND METHODS

The main components of Platycladi Semen were characterized by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). The anxiolytic effects of oral Platycladi Semen were evaluated in chronic unpredictable mild stress (CUMS) induced mice. To explore the anxiolytic mechanisms of Platycladi Semen, serum non-targeted metabolomics combined with network pharmacology and molecular docking was performed.

RESULTS

Fourteen compounds were identified in the 50% methanol extract and 11 fatty acid derivatives were identified in the methyl-esterified fatty oil of Platycladi Semen. In CUMS mice, both the aqueous extract and fatty oil of Platycladi Semen had anxiolytic effects, which were shown by the increase in the time and frequency of mice entering the open arm in the elevated plus maze (EPM) experiment. Through serum non-targeted metabolomics, 34 differential metabolites were identified, and lipid metabolic pathways such as sphingolipid metabolism, steroidogenesis, alpha-linoleic acid, and linoleic acid metabolism were enriched. Through network pharmacology, 109 targets of the main components in Platycladi Semen were identified, and the 'neuroactive ligand-receptor interaction' and 'lipid metabolism' were enriched. The molecular docking results showed that the main components in Platycladi Semen could bind to the key targets such as peroxisome proliferator-activated receptor delta (PPARD), peroxisome proliferator-activated receptor alpha (PPARA), fatty acid binding protein 5 (FABP5), fatty acid binding protein 3 (FABP3), peroxisome proliferator-activated receptor gamma (PPARG), arachidonate 5-lipoxygenase (ALOX5) and fatty acid amide hydrolase (FAAH).

CONCLUSION

This study indicated that Platycladi Semen has anxiolytic effects, and the anxiolytic mechanisms may be the regulation of lipid metabolism and the neuroactive ligand-receptor interaction.

Dietary interventions for perinatal depression and anxiety: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Dietary interventions are a widely available intervention for depression and anxiety among pregnant and/or postpartum (i.e., perinatal) persons but their effectiveness is not well known.

OBJECTIVE

We performed a systematic review and meta-analysis to assess the effectiveness of dietary interventions for the treatment of perinatal depression and/or anxiety.

DESIGN

We searched Medline, EMBASE, PsycINFO, CINAHL, and Web of Science from their inception to November 2, 2022. Studies were included if they were available in English and examined the effectiveness of a dietary intervention for perinatal depression and/or anxiety in a randomized controlled trial.

RESULTS

Our search identified 4,246 articles, 36 of which were included and 28 were eligible for meta-analysis. Random effects meta-analyses were performed. Polyunsaturated fatty acids (PUFAs) were not found to improve symptoms of perinatal depression compared to control conditions (SMD -0.11; 95% CI -0.26 to 0.04). These results did not change when examined during pregnancy or the postpartum period separately, nor did they vary according to fatty acid ratio. Elemental metals (iron, zinc, and magnesium) were also not found to be superior to placebo (SMD, -0.42; 95% CI, -1.05 to 0.21), though, vitamin D yielded a small to medium effect size improvements (SMD, -0.52; 95% CI, -0.84 to -0.20) in postpartum depression. Iron may help in those with confirmed iron deficiency. Narrative synthesis was performed for studies ineligible for meta-analyses.

CONCLUSIONS

Despite their widespread popularity, PUFAs and elemental metals do not appear to effectively reduce perinatal depression. Vitamin D taken in doses of 1800 to 3500 International Units (IU) per day may have some promise. Additional high-quality, large-scale randomized controlled trials (RCTs) are needed to determine the true effectiveness of dietary interventions on perinatal depression and/or anxiety.

PROSPERO REGISTRATION DATE AND NUMBER

July 5^th 2020, CRD42020208830.

Causal effects of fatty acids on depression: Mendelian randomization study

Objectives

Fatty acids (FA) are widely believed to play a role in the pathophysiology of depression. However, the causal relationships between FA and depression remain elusive and warrant further research. We aimed to investigate the potential causal relationship between FA [saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA)] and the risk of depression using Mendelian randomization (MR) analysis.

Methods

We conducted a two-sample MR analysis using large-scale European-based genome-wide association studies (GWASs) summary data related to depression (n = 500,199 individuals) and FA [saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA)] levels. MR analysis was performed using the Wald ratio and inverse variance-weighted (IVW) methods, and sensitivity analysis was conducted by the simple mode, weighted mode, weighted median method, and MR-Egger method.

Results

We found the causal effects for the levels of oleic acid (OA; OR = 1.07, p = 5.72 × 10^-4), adrenic acid (OR = 0.74, p = 1.01 × 10^-3), α-linolenic acid (ALA; OR = 2.52, p = 1.01 × 10^-3), eicosapentaenoic acid (EPA; OR = 0.84, p = 3.11 × 10^-3) on depression risk, after Bonferroni correction. The sensitivity analyses indicated similar trends. No causal effect between the levels of SFA and depression risk was observed.

Conclusion

Our study suggests that adrenic acid and EPA are protective against the risk of depression, while OA and ALA are potential risk factors for depression. Nonetheless, the underlying mechanisms that mediate the association between these FAs and depression risk should be investigated in further experiments.

Combinatorial panel with endophenotypes from multilevel information of diffusion tensor imaging and lipid profile as predictors for depression

OBJECTIVE

Clinical heterogeneity in major depressive disorder likely reflects the range of etiology and contributing factors in the disorder, such as genetic risk. Identification of more refined subgroups based on biomarkers such as white matter integrity and lipid-related metabolites could facilitate precision medicine in major depressive disorder.

METHODS

A total of 148 participants (15 genetic high-risk participants, 57 patients with first-episode major depressive disorder and 76 healthy controls) underwent diffusion tensor imaging and plasma lipid profiling. Alterations in white matter integrity and lipid metabolites were identified in genetic high-risk participants and patients with first-episode major depressive disorder. Then, shared alterations between genetic high-risk and first-episode major depressive disorder were used to develop an imaging x metabolite diagnostic panel for genetically based major depressive disorder via factor analysis and logistic regression. A fivefold cross-validation test was performed to evaluate the diagnostic panel.

RESULTS

Alterations of white matter integrity in corona radiata, superior longitudinal fasciculus and the body of corpus callosum and dysregulated unsaturated fatty acid metabolism were identified in both genetic high-risk participants and patients with first-episode major depressive disorder. An imaging x metabolite diagnostic panel, consisting of measures for white matter integrity and unsaturated fatty acid metabolism, was identified that achieved an area under the receiver operating characteristic curve of 0.86 and had a significantly higher diagnostic performance than that using either measure alone. And cross-validation confirmed the adequate reliability and accuracy of the diagnostic panel.

CONCLUSION

Combining white matter integrity in corpus callosum, superior longitudinal fasciculus and corona radiata, and unsaturated fatty acid profile may improve the identification of genetically based endophenotypes in major depressive disorder to advance precision medicine strategies.

Nutrition and bipolar disorder: a systematic review

INTRODUCTION

Individuals with bipolar disorder (BD) have higher rates of unhealthy lifestyles and risk for medical comorbidities Research currently suggests that dietary factors may play a role in the development of depression and anxiety. Therefore, nutritional approaches are potential strategies for the treatment of BD. The aim of this review is to summarize the available evidence on nutrition and BD.

MATERIALS AND METHODS

The paper was developed based on PRISMA 2020 guidelines. The search was conducted in Sep-2021 using PubMed and Cochrane Library, augmented by manually checked references lists. The search found 986 studies, of which 47 were included, combined with 13 from reference lists, totaling 60 studies.

RESULTS

There were 33 observational trials, of which 15 focused on fatty acids, 9 on micronutrients, 5 on specific foods, 4 on macro and micronutrients. The 27 interventional studies mainly focused on fatty acids, micronutrients and N-acetylcysteine (NAC).

DISCUSSION

Dietary intake or supplementation of unsaturated fatty acids, mainly Omega-3 seems to be associated with improved BD symptoms, along with seafood, folic acid and zinc. Studies found variable, mainly non-significant impacts of creatine, carnitine, vitamin D, inositol or NAC supplementation on BD. There are promising results associated with Coenzyme Q10 (Coq10) and probiotics. Taken together, these preliminary findings suggest that dietetic approaches might be included as part of BD treatment. Also considering the high risk of metabolic disorders in individuals with BD, they should be encouraged to choose healthy dietary lifestyles, including daily intake of fruits, vegetables, seafood and whole grains.

Fish oil supplementation alters emotion-generated corticolimbic functional connectivity in depressed adolescents at high-risk for bipolar I disorder: A 12-week placebo-controlled fMRI trial

OBJECTIVE

To evaluate the effects of fish oil (FO), a source of the omega-3 polyunsaturated fatty acids (n-3 PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on emotion-generated corticolimbic functional connectivity in depressed youth at high risk for developing bipolar I disorder.

METHODS

Thirty-nine antidepressant-free youth with a current depressive disorder diagnosis and a biological parent with bipolar I disorder were randomized to 12-week double-blind treatment with FO or placebo. At baseline and endpoint, fMRI (4 Tesla) scans were obtained while performing a continuous performance task with emotional and neutral distractors (CPT-END). Seed-to-voxel functional connectivity analyses were performed using bilateral orbitofrontal cortex (OFC) and amygdala (AMY) seeds. Measures of depression, mania, global symptom severity, and erythrocyte fatty acids were obtained.

RESULTS

Erythrocyte EPA+DHA composition increased significantly in the FO group (+47%, p ≤ 0.0001) but not in the placebo group (-10%, p = 0.11). Significant group by time interactions were found for functional connectivity between the left OFC and the left superior temporal gyrus (STG) and between the right AMY and right inferior temporal gyrus (ITG). OFC-STG connectivity increased in the FO group (p = 0.0001) and decreased in the placebo group (p = 0.0019), and AMY-ITG connectivity decreased in the FO group (p = 0.0014) and increased in the placebo group (p < 0.0001). In the FO group, but not placebo group, the decrease in AMY-ITG functional connectivity correlated with decreases in Childhood Depression Rating Scale-Revised and Clinical Global Impression-Severity Scale scores.

CONCLUSIONS

In depressed high-risk youth FO supplementation alters emotion-generated corticolimbic functional connectivity which correlates with changes in symptom severity ratings.

Bioprospecting lipid-producing microorganisms: From metagenomic-assisted isolation techniques to industrial application and innovations

Traditionally, lipid-producing microorganisms have been obtained via conventional bioprospecting based on isolation and screening techniques, demanding time and effort. Thus, high-throughput sequencing combined with conventional microbiological approaches has emerged as an advanced and rapid strategy for recovering novel oleaginous microorganisms from target environments. This review highlights recent developments in lipid-producing microorganism bioprospecting, following (i) from traditional cultivation techniques to state-of-the-art metagenomics approaches; (ii) related topics on workflow, next-generation sequencing platforms, and knowledge bioinformatics; and (iii) biotechnological potential of the production of docosahexaenoic acid (DHA) by Aurantiochytrium limacinum, arachidonic acid (ARA) by Mortierella alpina and biodiesel by Rhodosporidium toruloides. These three species have been shown to be highly promising and studied in research articles, patents and commercialized products. Trends, innovations and future perspectives of these microorganisms are also addressed. Thus, these microbial lipids allow the development of food, feed and biofuels as alternative solutions to animal and vegetable oils.

The Role of Nutraceuticals in Osteoarthritis Prevention and Treatment: Focus on n-3 PUFAs

Osteoarthritis (OA) is a disease caused by joint degeneration with massive cartilage loss, and obesity is among the risk factors for its onset, though the pathophysiological mechanisms underlying the disease and better therapeutic approach still remain to be assessed. In recent years, several nutraceutical interventions have been investigated in order to define better solutions for preventing and treating OA. Among them, polyunsaturated fatty acids (n-3 PUFAs) appear to represent potential candidates in counteracting OA and its consequences, due to their anti-inflammatory, antioxidant, and chondroinductive effects. PUFAs have been found to counteract the onset and progression of OA by reducing bone and cartilage destruction, inhibiting proinflammatory cytokine release, reactive oxygen species (ROS) generation, and the NF-κB pathway's activation. Moreover, a diet rich in n-3 PUFAs and their derivatives (maresins and resolvins) demonstrates beneficial effects on associated pain reduction. Finally, it has been shown that together with the anti-inflammatory and antioxidant properties of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, their antiapoptotic and antiangiogenic effects contribute in reducing OA development. The present review is aimed at assessing evidence suggesting the potential benefit of nutraceutical supplementation with PUFAs in OA management according to their efficacy in targeting relevant pathophysiological mechanisms responsible for inflammation and joint destruction processes, and this may represent a novel and potentially useful approach in OA prevention and treatment. For that purpose, a PubMed literature survey was conducted with a focus on some in vitro and in vivo studies and clinical trials from 2015 to 2020.

N-3 PUFA ameliorated bone loss induced by postmenopausal depression following exposure to chronic mild stress and maternal separation by regulating neuronal processes

Depression induced by chronic mild stress (CMS) reduced bone mass in ovariectomized (OVX) rats, and maternal separation (MS) during early life aggravated depression-induced bone mass destruction. N-3 polyunsaturated fatty acids (PUFA) have been shown to improve bone mass and depression, but the bone-protecting effects of n-3 PUFA were unclear in CMS+MS-induced depression models. The purpose of this study was to determine whether n-3 PUFA improved CMS+MS-induced postmenopausal bone loss via its antidepressant-like action. Rats were fed diets containing 0% of total energy intake (en %) of n-3 PUFA during lifetime or 1 en % n-3 PUFA during pre-weaning or post-weaning periods, or their entire lifetimes and were allocated to CMS or CMS+MS groups after OVX. Lifetime supply of n-3 PUFA enhanced bone mass and microarchitecture, and expression of runt-related transcription factor 2, while decreasing blood levels of amino-terminal cross-linked telopeptide of type 1 collagen and the expression of receptor activator of nuclear factor kappa Β ligand/osteoprotegerin, activating transcription factor 4, and adrenergic receptor β2. Lifetime supply of n-3 PUFA decreased levels of adrenocorticotropic hormone and corticosterone and the expression of corticotropin-releasing factor in the brain but increased expression of the glucocorticoid receptor, serotonin-2C receptor, cAMP response element-binding protein (CREB), and calmodulin kinase IV and serotonin levels. Supply of n-3 PUFA during the pre-and post-weaning periods had beneficial effects on the brain but not on the bones. Lifetime supply of n-3 PUFA ameliorated bone loss induced by chronic stress by regulating hypothalamic-pituitary-adrenal axis activity and serotonin-CREB signaling.

PUFA Supplementation and Heart Failure: Effects on Fibrosis and Cardiac Remodeling

Heart failure (HF) characterized by cardiac remodeling is a condition in which inflammation and fibrosis play a key role. Dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) seems to produce good results. In fact, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti-inflammatory and antioxidant properties and different cardioprotective mechanisms. In particular, following their interaction with the nuclear factor erythropoietin 2 related factor 2 (NRF2), the free fatty acid receptor 4 (Ffar4) receptor, or the G-protein coupled receptor 120 (GPR120) fibroblast receptors, they inhibit cardiac fibrosis and protect the heart from HF onset. Furthermore, n-3 PUFAs increase the left ventricular ejection fraction (LVEF), reduce global longitudinal deformation, E/e ratio (early ventricular filling and early mitral annulus velocity), soluble interleukin-1 receptor-like 1 (sST2) and high-sensitive C Reactive protein (hsCRP) levels, and increase flow-mediated dilation. Moreover, lower levels of brain natriuretic peptide (BNP) and serum norepinephrine (sNE) are reported and have a positive effect on cardiac hemodynamics. In addition, they reduce cardiac remodeling and inflammation by protecting patients from HF onset after myocardial infarction (MI). The positive effects of PUFA supplementation are associated with treatment duration and a daily dosage of 1–2 g. Therefore, both the European Society of Cardiology (ESC) and the American College of Cardiology/American Heart Association (ACC/AHA) define dietary supplementation with n-3 PUFAs as an effective therapy for reducing the risk of hospitalization and death in HF patients. In this review, we seek to highlight the most recent studies related to the effect of PUFA supplementation in HF. For that purpose, a PubMed literature survey was conducted with a focus on various in vitro and in vivo studies and clinical trials from 2015 to 2021.

Advances in improving the biotechnological application of oleaginous fungus Mortierella alpina

Mortierella alpina is an oleaginous filamentous fungus with considerable lipid productivity, and it has been widely used for industrial production of arachidonic acid. The fermentation process of M. alpina is complicated and can be affected by various factors; therefore, a comprehensive knowledge of its metabolic characteristics and key factors governing lipid biosynthesis is required to further improve its industrial performance. In this review, we discuss the metabolic features and extracellular factors that affect lipid biosynthesis in M. alpina. The current progress in fermentation optimisation and metabolic engineering to improve lipid yield are also summarised. Moreover, we review the applications of M. alpina in the food industry and propose fermentation strategies for better utilisation of this genus in the future. In our opinion, the economic performance of M. alpina should be enhanced from multiple levels, including strains with ideal traits, efficient fermentation strategies, controllable fermentation costs, and competitive products of both high value and productivity. By reviewing the peculiarities of M. alpina and current progress to improve its suitability for biotechnological production, we wish to provide more efficient strategies for future development of M. alpina as a high-value lipid cell factory. KEY POINTS: • Understanding M. alpina metabolism is helpful for rational design of its fermentation processes. • Nitrogen source is a key point that affects PUFA's component and fermentation cost in M. alpina. • Dynamic fermentation strategy combined with breeding is needed to increase lipid yield in M. alpina.

Targeting Metabolic Dysfunction for the Treatment of Mood Disorders: Review of the Evidence

Major depressive disorder (MDD) and bipolar disorder (BD) are often chronic with many patients not responding to available treatments. As these mood disorders are frequently associated with metabolic dysfunction, there has been increased interest in novel treatments that would target metabolic pathways. The objectives of this scoping review were to synthesize evidence on the impact on mood symptoms of lipid lowering agents and anti-diabetics drugs, while also reviewing current knowledge on the association between mood disorders and dyslipidemia or hyperglycemia. We propose that metabolic dysfunction is prevalent in both MDD and BD and it may contribute to the development of these disorders through a variety of pathophysiological processes including inflammation, brain structural changes, hormonal alterations, neurotransmitter disruptions, alteration on brain cholesterol, central insulin resistance, and changes in gut microbiota. Current evidence is conflicting on the use of statins, polyunsaturated fatty acids, thiazolidinediones, glucagon-like peptide agonists, metformin, or insulin for the treatment of MDD and BD. Given the paucity of high-quality randomized controlled trials, additional studies are needed before any of these medications can be repurposed in routine clinical practice. Future trials need to enrich patient recruitment, include evaluations of mechanism of action, and explore differential effects on specific symptom domains such as anhedonia, suicidality, and cognition.

Plasma metabolites changes in male heroin addicts during acute and protracted withdrawal

BACKGROUND

Heroin addiction and withdrawal have been associated with an increased risk for infectious diseases and psychological complications. However, the changes of metabolites in heroin addicts during withdrawal remain largely unknown.

METHODS

A total of 50 participants including 20 heroin addicts with acute abstinence stage, 15 with protracted abstinence stage and 15 healthy controls, were recruited. We performed metabolic profiling of plasma samples based on ultraperformance liquid chromatography coupled to tandem mass spectrometry to explore the potential biomarkers and mechanisms of heroin withdrawal.

RESULTS

Among the metabolites analyzed, omega-6 polyunsaturated fatty acids (linoleic acid, dihomo-gamma-linolenic acid, arachidonic acid, n-6 docosapentaenoic acid), omega-3 polyunsaturated fatty acids (docosahexaenoic acid, docosapentaenoic acid), aromatic amino acids (phenylalanine, tyrosine, tryptophan), and intermediates of the tricarboxylic acid cycle (oxoglutaric acid, isocitric acid) were significantly reduced during acute heroin withdrawal. Although majority of the metabolite changes could recover after months of withdrawal, the levels of alpha-aminobutyric acid, alloisoleucine, ketoleucine, and oxalic acid do not recover.

CONCLUSIONS

In conclusion, the plasma metabolites undergo tremendous changes during heroin withdrawal. Through metabolomic analysis, we have identified links between a framework of metabolic perturbations and withdrawal stages in heroin addicts.

N-3 PUFA improved post-menopausal depression induced by maternal separation and chronic mild stress through serotonergic pathway in rats-effect associated with lipid mediators

Early life maternal separation (MS) increases the vulnerability to depression in rats with chronic mild stress (CMS). N-3 polyunsaturated fatty acids (PUFA) improved depressive behaviors in rats with acute stress; however, their effects on rats with MS+CMS were not apparent. The purpose of the present study was to investigate the hypothesis that lifetime n-3 PUFA supplementation improves post-menopausal depression through the serotonergic and glutamatergic pathways while modulating n-3 PUFA-derived metabolites. Female rats were fed diets of either 0% n-3 PUFA during lifetime or 1% energy n-3 PUFA during pre-weaning, post-weaning, or lifetime periods. Rats were allocated to non-MS or MS groups and underwent CMS after ovariectomy. N-3 PUFA increased brain n-3 PUFA-derived endocannabinoid/oxylipin levels, and reversed depressive behaviors. N-3 PUFA decreased blood levels of adrenocorticotropic hormone and corticosterone, and brain expressions of corticotropin-releasing factor and miRNA-218, which increased the expression of the glucocorticoid receptor. N-3 PUFA decreased the expression of tumor necrosis factor-α, interleukin (IL)-6, IL-1β, and prostaglandin E2, while increased the expression of miRNA-155. N-3 PUFA also increased brainstem serotonin levels and hippocampal expression of the serotonin-1A receptor, cAMP response element-binding protein (CREB), phospho-CREB, and brain-derived neurotrophic factor. However, n-3 PUFA did not affect brain expression of α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor subtype 1, N-methyl-D-aspartate receptor subtype 2B, or miRNA-132. Moreover, n-3 PUFA exposure during lifetime caused greater effects than pre- and post-weaning periods. The present study suggested that n-3 PUFA improved depressive behaviors through serotonergic pathway while modulating the metabolites of n-3 PUFA in post-menopausal depressed rats with chronic stress.

Epigenetic Element-Based Transcriptome-Wide Association Study Identifies Novel Genes for Bipolar Disorder

Since the bipolar disorder (BD) signals identified by genome-wide association study (GWAS) often reside in the non-coding regions, understanding the biological relevance of these genetic loci has proven to be complicated. Transcriptome-wide association studies (TWAS) providing a powerful approach to identify novel disease risk genes and uncover possible causal genes at loci identified previously by GWAS. However, these methods did not consider the importance of epigenetic regulation in gene expression. Here, we developed a novel epigenetic element-based transcriptome-wide association study (ETWAS) that tested the effects of genetic variants on gene expression levels with the epigenetic features as prior and further mediated the association between predicted expression and BD. We conducted an ETWAS consisting of 20 352 cases and 31 358 controls and identified 44 transcriptome-wide significant hits. We found 14 conditionally independent genes, and 10 genes that did not previously implicate with BD were regarded as novel candidate genes, such as ASB16 in the cerebellar hemisphere (P = 9.29 × 10-8). We demonstrated that several genome-wide significant signals from the BD GWAS driven by genetically regulated expression, and NEK4 explained 90.1% of the GWAS signal. Additionally, ETWAS identified genes could explain heritability beyond that explained by GWAS-associated SNPs (P = 5.60 × 10-66). By querying the SNPs in the final models of identified genes in phenome databases, we identified several phenotypes previously associated with BD, such as schizophrenia and depression. In conclusion, ETWAS is a powerful method, and we identified several novel candidate genes associated with BD.

Effects of n-3 Polyunsaturated Fatty Acid Supplementation in the Prevention and Treatment of Depressive Disorders-A Systematic Review and Meta-Analysis

N-3 polyunsaturated fatty acids (PUFAs) have been suggested to affect depressive disorders. This review aims to determine the effect of n-3 PUFAs on depressive symptoms in people with or without diagnosed depression. Medline, PsycINFO, and Cochrane CENTRAL databases were searched for randomized controlled trials (RCTs) assessing the association between n-3 PUFAs and depressive symptoms or disorders as outcomes. A random-effects meta-analysis of standardized mean difference (SMD) with 95% confidence intervals (CI) was performed. Twenty-five studies (7682 participants) were included. Our meta-analysis (20 studies) indicated that n-3 PUFA supplementation lowered depressive symptomology as compared with placebo: SMD = −0.34, 95% CI: −0.55, −0.12, I² = 86%, n = 5836, but a possible publication bias cannot be ruled out. Subgroup analyses indicated no statistically significant difference by treatment duration of <12 vs. ≥12 weeks, presence of comorbidity, or severity of depressive symptoms. Nevertheless, beneficial effects were seen in the subgroups of studies with longer treatment duration and with no depression and mild to moderate depression. Subgroup analysis by eicosapentaenoic acid (EPA) dosage revealed differences in favor of the lower EPA dosage. Sensitivity analysis including studies with low risk of bias seems to confirm the overall result. Supplementation of n-3 PUFA appears to have a modest beneficial effect on depressive symptomology, although the quality of evidence is still insufficient.

Inflammatory Depression-Mechanisms and Non-Pharmacological Interventions

Treatment of depression is hampered by the failure to identify distinct symptom profiles with distinct pathophysiologies that differentially respond to distinct treatments. We posit that inflammatory depression is a meaningful depression subtype associated with specific symptoms and biological abnormalities. We review several upstream, potentially causative, mechanisms driving low-grade inflammation in this subtype of depression. We also discuss downstream mechanisms mediating the link between inflammation and symptoms of depression, including alterations in dopaminergic neurotransmission and tryptophan metabolism. Finally, we review evidence for several non-pharmacological interventions for inflammatory depression, including probiotics, omega-3 fatty acids, and physical exercise interventions. While some evidence suggests that these interventions may be efficacious in inflammatory depression, future clinical trials should consider enriching patient populations for inflammatory markers, or stratify patients by inflammatory status, to confirm or refute this hypothesis.

Endothelial dysfunction in neuroprogressive disorders-causes and suggested treatments

BACKGROUND

Potential routes whereby systemic inflammation, oxidative stress and mitochondrial dysfunction may drive the development of endothelial dysfunction and atherosclerosis, even in an environment of low cholesterol, are examined.

MAIN TEXT

Key molecular players involved in the regulation of endothelial cell function are described, including PECAM-1, VE-cadherin, VEGFRs, SFK, Rho GEF TRIO, RAC-1, ITAM, SHP-2, MAPK/ERK, STAT-3, NF-κB, PI3K/AKT, eNOS, nitric oxide, miRNAs, KLF-4 and KLF-2. The key roles of platelet activation, xanthene oxidase and myeloperoxidase in the genesis of endothelial cell dysfunction and activation are detailed. The following roles of circulating reactive oxygen species (ROS), reactive nitrogen species and pro-inflammatory cytokines in the development of endothelial cell dysfunction are then described: paracrine signalling by circulating hydrogen peroxide, inhibition of eNOS and increased levels of mitochondrial ROS, including compromised mitochondrial dynamics, loss of calcium ion homeostasis and inactivation of SIRT-1-mediated signalling pathways. Next, loss of cellular redox homeostasis is considered, including further aspects of the roles of hydrogen peroxide signalling, the pathological consequences of elevated NF-κB, compromised S-nitrosylation and the development of hypernitrosylation and increased transcription of atherogenic miRNAs. These molecular aspects are then applied to neuroprogressive disorders by considering the following potential generators of endothelial dysfunction and activation in major depressive disorder, bipolar disorder and schizophrenia: NF-κB; platelet activation; atherogenic miRs; myeloperoxidase; xanthene oxidase and uric acid; and inflammation, oxidative stress, nitrosative stress and mitochondrial dysfunction.

CONCLUSIONS

Finally, on the basis of the above molecular mechanisms, details are given of potential treatment options for mitigating endothelial cell dysfunction and activation in neuroprogressive disorders.

Polyunsaturated fatty acid supplement alleviates depression-incident cognitive dysfunction by protecting the cerebrovascular and glymphatic systems

INTRODUCTION

Depression, the most prevalent mood disorder, has high comorbidity with cerebrovascular disease and cognitive decline. However, there is little understanding of the cellular mechanisms involved in depression and its comorbid cerebrovascular damage and cognition impairment. Here, we tested the prediction that the chronic unpredictable mild stress (CUMS) mouse model would manifest in disturbed glymphatic function and that dietary supplementation with polyunsaturated fatty acids (PUFA) could ameliorate these deficits while alleviating the depression-associated cognitive decline.

METHODS

To test the treatment effects of PUFA or Es on behaviours, we applied the tail suspension, open field, and sucrose preference tests to assess depressive symptoms, and applied the Morris water maze test to assess cognition in groups of control, chronic unpredictable mild stress (CUMS), PUFA, and escitalopram (Es) treatment. We measured the extracellular concentrations of dopamine (DA), 5-hydroxytryptamine (5-HT) and noradrenaline (NA) in microdialysates from prefrontal cortex (PFC) by liquid chromatography mass spectrometry. Glia cells and inflammatory factors were analysed with fluorescent immunochemistry and western blot, respectively. We tested brain vasomotor function with two-photon and laser speckle imaging in vivo, and measured glymphatic system function by two-photon imaging in vivo and fluorescence tracer imaging ex vivo, using awake and anesthetized mice. Besides, we monitored cortical spreading depression by laser speckle imaging system. AQP4 depolarization is analysed by fluorescent immunochemistry and western blot.

RESULTS

We confirmed that CUMS elicited depression-like and amnestic symptoms, accompanied by decreased monoamines neurotransmitter concentration in PFC and upregulated neuroinflammation markers. Moreover, CUMS mice showed reduced arterial pulsation and compliance in brain, and exhibited depolarized expression of AQP4, thus indicating glymphatic dysfunction both in awake and anesthetized states. PUFA supplementation rescued depression-like behaviours of CUMS mice, reduced neuroinflammation and cerebrovascular dysfunction, ultimately improved cognitive performance, all of which accompanied by restoring glymphatic system function. In contrast, Es treatment alleviated only the depression-like behavioural symptoms, while showing no effects on glymphatic function and depression-incident cognitive deficits.

CONCLUSIONS

The CUMS depression model entails suppression of the glymphatic system. PUFA supplementation rescued most behavioural signs of depression and the associated cognitive dysfunction by restoring the underlying glymphatic system disruption and protecting cerebral vascular function.

N-3 PUFA improved pup separation-induced postpartum depression via serotonergic pathway regulated by miRNA

Stress and ovarian hormone fluctuation are risk factors for postpartum depression (PPD). Previous studies suggested antidepressant-like effects of n-3 polyunsaturated fatty acids (PUFA), but their effect on dam animal with additional stress were not clear. The purpose of the present study was to investigate the hypothesis that n-3 PUFA improved PPD through the serotonergic and glutamatergic pathways by modulating miRNA. Rats were fed n-3 PUFA or control diet from gestation, with pup separation (PS) on postpartum days 2-14 and non-PS controls. N-3 PUFA reversed PS-induced depressive behaviors, including increased immobility, latencies to contact first pup and retrieve all pups, and decreased sucrose preference. N-3 PUFA also modulated the hypothalamic-pituitary-adrenal (HPA) axis by decreasing circulating levels of adrenocorticotropic hormone and corticosterone and expression of hypothalamic corticotrophin releasing factor and hippocampal miRNA-218 but increasing the hippocampal expression of glucocorticoid receptor. N-3 PUFA inhibited neuroinflammation by decreasing circulating levels of prostaglandin E₂ and hippocampal expression of tumor necrosis factor-α, interleukin-6, and miRNA-155. In addition, n-3 PUFA up-regulated the serotonergic pathway by increasing circulating levels of serotonin and hippocampal expression of serotonin-1A receptor, cAMP response element binding protein (CREB), pCREB, brain-derived neurotrophic factor, and miRNA-182 but did not affect the glutamatergic pathway according to the hippocampal expression of N-methyl-D-aspartate receptor-2B. The present study suggested that n-3 PUFA improved PPD through the serotonergic pathway by modifying the HPA axis, neuroinflammation, and related miRNAs.

Bidirectional longitudinal associations of omega-3 polyunsaturated fatty acid plasma levels with depressive disorders

BACKGROUND

Temporality of the association of low omega-3 polyunsaturated fatty acid (n-3 PUFA) plasma levels with depression remains questionable. To determine the underlying nature of these associations, this study examined the bidirectional longitudinal associations of n-3 PUFA plasma levels with (presence, onset and course of) depressive disorders and symptoms.

METHODS

Baseline (n = 2912, 28.6% with current depressive disorder) and 6-year follow-up data (n = 1966, 13.0% with current depressive disorder) of the Netherlands Study of Depression and Anxiety (NESDA) were used. Depression diagnoses and symptoms were based on psychiatric interviews and self-report questionnaires. N-3 PUFA levels (ratio of total fatty acids (mmol%)), were assessed using nuclear magnetic resonance.

RESULTS

Using two waves of data, n-3 PUFA levels were lower among depressed persons, as compared to healthy controls (Beta = -0.047, SE = 0.011, p < .001). Nevertheless, baseline n-3 PUFA levels were not consistently associated with subsequent change in depressive symptoms, onset or remission of depressive disorders over 6 years. Furthermore, the difference in n-3 PUFA levels detected at baseline between depressed and non-depressed participants tended to dissipate over 6 years (depression-by-time estimate: p = .011). Finally, subjects depressed both at baseline and at 6-year follow up had consistently lower n-3 PUFA levels over the entire follow-up as compared to those who had never been depressed. Change in depressive disorders across waves was not consistently accompanied by change in n-3 PUFA levels over time.

LIMITATIONS

No data on intermediate time points and EPA levels were available.

CONCLUSIONS

Despite significant cross-sectional associations between n-3 PUFA plasma levels and depressive disorders and severity, this 6-year longitudinal study could not confirm an uni- or bidirectional association over time. The association between depression and n-3 PUFA plasma levels is unlikely to be causal.

Neurodevelopmental pathways in bipolar disorder

Aberrations in neurodevelopmental trajectories have been implicated in the neurobiology of several mental disorders and evidence indicates a pathophysiological and genetic overlap of schizophrenia and bipolar disorder (BD). In this narrative review, we summarize findings related to developmental and perinatal factors as well as epidemiological, clinical, neuropsychological, brain imaging, postmortem brain and genomic studies that provide evidence for a putative neurodevelopmental pathogenesis and etiology of BD. Overall, aberrations in neurodevelopmental pathways have been more consistently implicated in the pathophysiology of schizophrenia compared to BD. Nevertheless, an accumulating body of evidence indicates that dysfunctional neurodevelopmental pathways may be implicated in the underlying pathophysiology of at least a subset of individuals with BD particularly those with an early age of illness onset and those exhibiting psychotic symptoms. A heuristic neurodevelopmental model for the pathophysiology of BD based on the findings of this review is proposed. Furthermore, we critically discuss clinical and research implications of this model. Finally, further research directions for this emerging field are provided.

Association of dietary n-3 polyunsaturated fatty acids intake with depressive symptoms in midlife women

BACKGROUND

To study the association of n-3 polyunsaturated fatty acid (n-3 PUFA) intake from diet with depressive symptoms in midlife women.

METHODS

Data for this cross-sectional study were retrieved from baseline assessment of the Study of Women's Health Across the Nation (SWAN). Logistic regression and restricted cubic spline models were performed to examine the association n-3 PUFA intake with depressive symptoms.

RESULTS

A total of 3054 women aged 42-52 years were included in the present study. In overall midlife women, n-3 PUFA intake was not significantly associated with depressive symptoms (CES-D score ≥16) after adjustment for potential confounders. In early perimenopausal women, n-3 PUFA intake was inversely associated with depressive symptoms after adjustment for potential confounders. The fully adjusted OR with 95% CI of depressive symptoms were 0.062 (0.009-0.457) in the highest quartile (n-3 PUFAs intake was categorized by quartiles) compared with the lowest quartile for n-3 PUFA intake. Restricted cubic spline analyses showed that n-3 PUFA intake were dose-response inversely associated with depressive symptoms in early perimenopausal women. However, in premenopausal women, no significant association between depressive symptoms and n-3 PUFA intake was observed.

LIMITATIONS

This was a cross-sectional study, limiting causal inferences.

CONCLUSION

Dietary n-3 PUFA may be inversely associated with depressive symptoms in early perimenopausal women, but not in premenopausal women.

Omega-3-polyunsatured fatty acids (O3PUFAs), compared to placebo, reduced symptoms of occupational burnout and lowered morning cortisol secretion

BACKGROUND

Occupational burnout is both a serious health concern at both public and individual levels. Treatment options are psychopharmacological, psychological and physical activity-related interventions. Here, we tested whether, compared to placebo, omega-3-polyunsaturated fatty acids (O3PUFAs) have a positive impact on burnout and morning cortisol secretion.

METHOD

A total of 43 individuals (mean age: 38.4 years, 76.7% females) took part in the present double-blind and placebo-controlled intervention. Participants were randomly assigned either to the O3PUFA or to the placebo condition. At baseline and again eight weeks later, participants completed the Maslach Burnout Inventory and collected morning saliva samples for analysis of the cortisol awakening response (CAR).

RESULTS

Emotional exhaustion and depersonalization decreased, and sense of personal accomplishment increased over time, but more so in the O3PUFA condition than in the placebo condition. Likewise, CAR decreased over time, but again more so in the O3PUFA condition than in the placebo condition.

CONCLUSIONS

The present pattern of results suggests that, compared to placebo, administration of daily omega-3-polyunsaturated fatty acids for eight consecutive weeks positively influences both psychological and physiological markers of occupational burnout.

Microarray analysis of gene expression in the diacylglycerol kinase η knockout mouse brain

We have revealed that diacylglycerol kinase η (DGKη)-knockout (KO) mice display bipolar disorder (BPD) remedy-sensitive mania-like behaviors. However, the molecular mechanisms causing the mania-like abnormal behaviors remain unclear. In the present study, microarray analysis was performed to determine global changes in gene expression in the DGKη-KO mouse brain. We found that the DGKη-KO brain had 43 differentially expressed genes and the following five affected biological pathways: "neuroactive ligand-receptor interaction", "transcription by RNA polymerase II", "cytosolic calcium ion concentration", "Jak-STAT signaling pathway" and "ERK1/2 cascade". Interestingly, mRNA levels of prolactin and growth hormone, which are augmented in BPD patients and model animals, were most strongly increased. Notably, all five biological pathways include at least one gene among prolactin, growth hormone, forkhead box P3, glucagon-like peptide 1 receptor and interleukin 1β, which were previously implicated in BPD. Consistent with the microarray data, phosphorylated ERK1/2 levels were decreased in the DGKη-KO brain. Microarray analysis showed that the expression levels of several glycerolipid metabolism-related genes were also changed. Liquid chromatography-mass spectrometry revealed that several polyunsaturated fatty acid (PUFA)-containing phosphatidic acid (PA) molecular species were significantly decreased as a result of DGKη deficiency, suggesting that the decrease affects PUFA metabolism. Intriguingly, the PUFA-containing lysoPA species were markedly decreased in DGKη-KO mouse blood. Taken together, our study provides not only key broad knowledge to gain novel insights into the underlying mechanisms for the mania-like behaviors but also information for developing BPD diagnostics.

Dietary Patterns: A New Therapeutic Approach for Depression?

Introduction:

The field of nutritional psychiatry is a fast-growing one. Although initially, it focused on the effects of vitamins and micronutrients in mental health, in the last decade, its focus also extended to the dietary patterns. The possibility of a dietary cost-effective intervention in the most common mental disorder, depression, cannot be overlooked due to its potential large-scale impact.

Method:

A classic review of the literature was conducted, and studies published between 2010 and 2018 focusing on the impact of dietary patterns in depression and depressive symptoms were included.

Results:

We found 10 studies that matched our criteria. Most studies showed an inverse association between healthy dietary patterns, rich in fruits, vegetables, lean meats, nuts and whole grains, and with low intake of processed and sugary foods, and depression and depressive symptoms throughout an array of age groups, although some authors reported statistical significance only in women. While most studies were of cross-sectional design, making it difficult to infer causality, a randomized controlled trial presented similar results.

Discussion:

he association between dietary patterns and depression is now well-established, although the exact etiological pathways are still unknown. Dietary intervention, with the implementation of healthier dietary patterns, closer to the traditional ones, can play an important role in the prevention and adjunctive therapy of depression and depressive symptoms.

Conclusion:

More large-scale randomized clinical trials need to be conducted, in order to confirm the association between high-quality dietary patterns and lower risk of depression and depressive symptoms.

Nut Oils and their Dietetic and Cosmetic Significance: a Review

Vegetable oils, which are a rich source of unsaturated fatty acids, phytosterols, vitamins and antioxidants, have a significant effect on the functioning and development of the body and contribute to health maintenance. They can be obtained from seeds, fruit stones, fruit, nuts or sprouts. This study discusses various species of plants that are sources of nut oils consumed in the daily diet and also used in the pharmaceutical and cosmetics industries.

Metabolomics Biomarkers for Precision Psychiatry

The treatment of psychiatric disorders remains a significant challenge in part due to imprecise diagnostic criteria and incomplete understanding of the molecular pathology involved. Current diagnostic and pharmacological treatment guidelines use a uniform approach to address each disorder even though psychiatric clinical presentation and prognosis within a disorder are known to be heterogeneous. Limited therapeutic success highlights the need for a precision medicine approach in psychiatry, termed precision psychiatry. To practice precision psychiatry, it is essential to research and develop multiple omics-based biomarkers that consider environmental factors and careful phenotype determination. Metabolomics, which lies at the endpoint of the "omics cascade," allows for detection of alterations in systems-level metabolites within biological pathways, thereby providing insights into the mechanisms that underlie various physiological conditions and pathologies. The eicosanoids, a family of metabolites derived from oxygenated polyunsaturated fatty acids, play a key role in inflammatory mechanisms and have been implicated in psychiatric disorders such as anorexia nervosa and depression. This review (1) provides background on the current clinical challenges of psychiatric disorders, (2) gives an overview of metabolomics application as a tool to develop improved biomarkers for precision psychiatry, and (3) summarizes current knowledge on metabolomics and lipidomic findings in common psychiatric disorders, with a focus on eicosanoids. Metabolomics is a promising tool for precision psychiatry. This research has great potential for both discovering biomarkers and elucidating molecular mechanisms underlying psychiatric disorders.

Influence of adjuvant omega-3-polyunsaturated fatty acids on depression, sleep, and emotion regulation among outpatients with major depressive disorders - Results from a double-blind, randomized and placebo-controlled clinical trial

BACKGROUND

Extant literature shows that adjuvant omega-3-polyunsaturated fatty acids (O3PUFAs) to a standard antidepressant medication impacts favorably on symptoms of depression in participants with major depressive disorders (MDD). The aim of the present study was to investigate, if and to what extent compared to placebo adjuvant O3PUFAs had a favorable impact on symptoms of depression, anxiety, sleep and emotion regulation among outpatients with MDD.

METHOD

A total of 50 outpatients (mean age: M = 42.46; 68% females) took part in this randomized, double-blind and placebo-controlled study. They were randomly assigned either to the O3PUFA- or to the placebo-condition. Standard medication was sertraline at therapeutic dosages. At baseline, six weeks and 12 weeks later at study completion participants completed questionnaires covering symptoms of depression, anxiety sensitivity, intolerance of uncertainty, sleep disturbances, and emotion regulation. In parallel, experts blind to participants' group assignment rated participants' depression with the Montgomery-Asberg Depression Scale.

RESULTS

Symptoms of depression (self- and experts' ratings) decreased over time, but more so in the O3PUFA condition, compared to the placebo condition. Likewise, anxiety sensitivity, intolerance of uncertainty and sleep disturbances improved, but again more so in the O3PUFA condition. Further, regulation and control of emotions and perception of other's emotions improved over time, but more so in the O3PUFA condition.

CONCLUSIONS

Among outpatients with MDD, and compared to placebo, adjuvant O3PUFAs to a standard medication improved not only symptoms of depression, but also dimensions of anxiety and sleep, and above all patients' competencies to regulate their emotions.

Docosahexaenoic acid (DHA): An essential nutrient and a nutraceutical for brain health and diseases

Docosahexaenoic acid (DHA), a polyunsaturated fatty acid (PUFA) enriched in phospholipids in the brain and retina, is known to play multi-functional roles in brain health and diseases. While arachidonic acid (AA) is released from membrane phospholipids by cytosolic phospholipase A2 (cPLA2), DHA is linked to action of the Ca2+-independent iPLA2. DHA undergoes enzymatic conversion by 15-lipoxygenase (Alox 15) to form oxylipins including resolvins and neuroprotectins, which are powerful lipid mediators. DHA can also undergo non-enzymatic conversion by reacting with oxygen free radicals (ROS), which cause the production of 4-hydoxyhexenal (4-HHE), an aldehyde derivative which can form adducts with DNA, proteins and lipids. In studies with both animal models and humans, there is evidence that inadequate intake of maternal n-3 PUFA may lead to aberrant development and function of the central nervous system (CNS). What is less certain is whether consumption of n-3 PUFA is important in maintaining brain health throughout one's life span. Evidence mostly from non-human studies suggests that DHA intake above normal nutritional requirements might modify the risk/course of a number of diseases of the brain. This concept has fueled much of the present interest in DHA research, in particular, in attempts to delineate mechanisms whereby DHA may serve as a nutraceutical and confer neuroprotective effects. Current studies have revealed ability for the oxylipins to regulation of cell redox homeostasis through the Nuclear factor (erythroid-derived 2)-like 2/Antioxidant response element (Nrf2/ARE) anti-oxidant pathway, and impact signaling pathways associated with neurotransmitters, and modulation of neuronal functions involving brain-derived neurotropic factor (BDNF). This review is aimed at describing recent studies elaborating these mechanisms with special regard to aging and Alzheimer's disease, autism spectrum disorder, schizophrenia, traumatic brain injury, and stroke.

Are Polyunsaturated Fatty Acids Implicated in Histaminergic Dysregulation in Bipolar Disorder?: AN HYPOTHESIS

Bipolar disorder (BD) is an extremely disabling psychiatric disease, characterized by alternate states of mania (or hypomania) and depression with euthymic states in between. Currently, patients receive pharmacological treatment with mood stabilizers, antipsychotics, and antidepressants. Unfortunately, not all patients respond well to this type of treatment. Bipolar patients are also more prone to heart and metabolic diseases as well as a higher risk of suicide compared to the healthy population. For a correct brain function is indispensable a right protein and lipids (e.g., fatty acids) balance. In particular, the amount of fatty acids in the brain corresponds to a 50–70% of the dry weight. It has been reported that in specific brain regions of BD patients there is a reduction in the content of unsaturated n-3 fatty acids. Accordingly, a diet rich in n-3 fatty acids has beneficial effects in BD patients, while their absence or high levels of saturated fatty acids in the diet are correlated to the risk of developing the disease. On the other hand, the histamine system is likely to be involved in the pathophysiology of several psychiatric diseases such as BD. Histamine is a neuromodulator involved in arousal, motivation, and energy balance; drugs acting on the histamine receptor H3 have shown potential as antidepressants and antipsychotics. The histaminergic system as other neurotransmission systems can be altered by fatty acid membrane composition. The purpose of this review is to explore how polyunsaturated fatty acids content alterations are related to the histaminergic system modulation and their impact in BD pathophysiology.

Coping with Stress During Aging: The Importance of a Resilient Brain

BACKGROUND

Resilience is the ability to achieve a positive outcome when we are in the face of adversity. It supposes an active resistance to adversity by coping mechanisms in which genetic, molecular, neural and environmental factors are involved. Resilience has been usually studied in early ages and few is known about it during aging.

METHODS

In this review, we will address the age-related changes in the brain mechanisms involved in regulating the stress response. Furthermore, using the EE paradigm, we analyse the resilient potential of this intervention and its neurobiological basis. In this case, we will focus on identifying the characteristics of a resilient brain (modifications in HPA structure and function, neurogenesis, specific neuron types, glia, neurotrophic factors, nitric oxide synthase or microRNAs, among others).

RESULTS

The evidence suggests that a healthy lifestyle has a crucial role to promote a resilient brain during aging. Along with the behavioral changes described, a better regulation of HPA axis, enhanced levels of postmitotic type-3 cells or changes in GABAergic neurotransmission are some of the brain mechanisms involved in resilience.

CONCLUSION

Future research should identify different biomarkers that increase the resistance to develop mood disorders and based on this knowledge, develop new potential therapeutic targets.

N-3 PUFA diet enrichment prevents amyloid beta-induced depressive-like phenotype

Among neuropsychiatric diseases, depression is one of the most prevalent. Many pathologies have been indicated as comorbid with depression and in particular, neurodegenerative disorders such as Alzheimer's diseases (AD). In this regard, several evidences endorse a strong relationship between depression and AD, so much that this mental illness has been proposed either as a risk factor for AD or as a prodromic AD phase. Furthermore, amyloid beta (Aβ) peptide, the main constituent of amyloid plaques commonly considered the principal hallmark of AD brains, has been shown to be increased, in its soluble form, in depressed patients. Accordingly, we have previously found that Aβ, intracerebroventricularly (i.c.v.) injected, is able to evoke a depressive-like profile in rats accompanied by low cortical serotonin and reduced neurotrophin content. Taking into account the great increase in AD and depression prevalence, many environmental factors have been under study, particularly dietary factors, and the role of polyunsaturated fatty acids (PUFA) is becoming central in this field of research. Thus, aim of the present study was to evaluate the neurobehavioral effects of lifelong exposure to either n-3 PUFA rich or n-3 PUFA poor diet after Aβ central administration. Results showed that n-3 PUFA enriched diet prevented the Aβ- induced depressive-like behaviors, as reveled by the reduction in the immobility time in the FST test. Furthermore, n-3 PUFA rich diet exposure reverted also serotonin and neurotrophin level reduction in prefrontal cortex of Aβ treated rats. Taken together, our data support the concept that supplementation of diet with n-3 PUFA represents a valid approach to reduce the risk of developing depressive symptoms, as well as reducing the risk of Aβ-related pathologies, such as AD.

Therapeutic potential of omega-3 fatty acid-derived epoxyeicosanoids in cardiovascular and inflammatory diseases

Numerous benefits have been attributed to dietary long-chain omega-3 polyunsaturated fatty acids (n-3 LC-PUFAs), including protection against cardiac arrhythmia, triglyceride-lowering, amelioration of inflammatory, and neurodegenerative disorders. This review covers recent findings indicating that a variety of these beneficial effects are mediated by "omega-3 epoxyeicosanoids", a class of novel n-3 LC-PUFA-derived lipid mediators, which are generated via the cytochrome P450 (CYP) epoxygenase pathway. CYP enzymes, previously identified as arachidonic acid (20:4n-6; AA) epoxygenases, accept eicosapentaenoic acid (20:5n-3; EPA) and docosahexaenoic acid (22:6n-3; DHA), the major fish oil n-3 LC-PUFAs, as efficient alternative substrates. In humans and rodents, dietary EPA/DHA supplementation causes a profound shift of the endogenous CYP-eicosanoid profile from AA- to EPA- and DHA-derived metabolites, increasing, in particular, the plasma and tissue levels of 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP). Based on preclinical studies, these omega-3 epoxyeicosanoids display cardioprotective, vasodilatory, anti-inflammatory, and anti-allergic properties that contribute to the beneficial effects of n-3 LC-PUFAs in diverse disease conditions ranging from cardiac disease, bronchial disorders, and intraocular neovascularization, to allergic intestinal inflammation and inflammatory pain. Increasing evidence also suggests that background nutrition as well as genetic and disease state-related factors could limit the response to EPA/DHA-supplementation by reducing the formation and/or enhancing the degradation of omega-3 epoxyeicosanoids. Recently, metabolically robust synthetic analogs mimicking the biological activities of 17,18-EEQ have been developed. These drug candidates may overcome limitations of dietary EPA/DHA supplementation and provide novel options for the treatment of cardiovascular and inflammatory diseases.

Emotion-Based Cognition in Mice Is Differentially Influenced by Dose and Chemical Form of Dietary Docosahexaenoic Acid

Docosahexaenoic acid (DHA) is a major constituent, and primary omega-3 fatty acid, in the brain. Evidence suggests that DHA consumption may promote cognitive functioning and prevent cognitive decline, and these effects may be particularly relevant in the context of fear or stress. However, the potency and efficacy of dietary DHA may depend on the form of DHA (e.g., phospholipid; PL vs. triglyceride; TG). In this study, we compared in mice the effects of consuming PL and TG forms of DHA on associative, avoidance (fear) based learning and memory. Diets consisted of either no DHA or 1%, 2%, and 4% PL- or TG-DHA. After 4 weeks on the test diets (n = 12/group), we used the 3-day passive avoidance (PA) and elevated plus maze (EPM) to examine fear and fear-associated learning and memory. We found a significant (p < 0.05) diet by time interaction in the PA and EPM. Compared to the control and the 1% TG-DHA group, mice consuming the diet supplemented with 1% PL-DHA displayed a significantly greater latency by test day 2 in the 3-day PA. No differences in latency between any of the groups were observed during trials 1 and 3. Mice consuming the 2% PL-DHA diet spent significantly more time frequenting the open arms during the first minute, but not the last 4 min, of the test. Compared to all other groups, mice fed the 4% TG-DHA diet had increased spleen, liver, and visceral fat weight. Consumption of the lower dose PL-DHA may confer enhanced efficacy, particularly on fear-based learning behavior.

From peroxisomal disorders to common neurodegenerative diseases - the role of ether phospholipids in the nervous system

The emerging diverse roles of ether (phospho)lipids in nervous system development and function in health and disease are currently attracting growing interest. Plasmalogens, a subgroup of ether lipids, are important membrane components involved in vesicle fusion and membrane raft composition. They store polyunsaturated fatty acids and may serve as antioxidants. Ether lipid metabolites act as precursors for the formation of glycosyl-phosphatidyl-inositol anchors; others, like platelet-activating factor, are implicated in signaling functions. Consolidating the available information, we attempt to provide molecular explanations for the dramatic neurological phenotype in ether lipid-deficient human patients and mice by linking individual functional properties of ether lipids with pathological features. Furthermore, recent publications have identified altered ether lipid levels in the context of many acquired neurological disorders including Alzheimer's disease (AD) and autism. Finally, current efforts to restore ether lipids in peroxisomal disorders as well as AD are critically reviewed.

Gluten related illnesses and severe mental disorders: a comprehensive review

The putative role of gluten in the pathophysiology of severe mental illnesses remains uncertain and there is doubt about the possible benefit of gluten-free diets for individuals affected by psychosis and mood disorders. The objective of this review was to summarize the findings linking gluten related conditions to pathophysiological substrates implicated in schizophrenia and mood disorders and review the evidences of potential benefits of glute-free diets in these populations. A literature search was conducted within PubMed and Scielo databases including references from inception until March 1st 2017. The strategy search was to use the key words "gluten", "celiac disease", "wheat", "bipolar disorder", "mood disorders", "psychosis", "schizophrenia", "depression". In the review about the potential efficacy of gluten-free diets in severe mental illnesses, we included only studies with original data, including cross sectional and longitudinal studies and clinical trials. Book chapters, review articles and meta-analysis and republished data were excluded. Although the current available evidences suggest that people with celiac disease or gluten allergy could have a slightly higher risk of schizophrenia and mood disorders compared to the general population, the literature review reveals significant inaccuracies in the data. There is insufficient evidence to recommend gluten-free diets for populations with psychosis and mood disorders.