Neuroprotective and Ameliorative Actions of Polyunsaturated Fatty Acids Against Neuronal Diseases: Beneficial Effect of Docosahexaenoic Acid on Cognitive Decline in Alzheimer’s Disease

The effects of omega-3, DHA, EPA, Souvenaid® in Alzheimer's disease: A systematic review and meta-analysis

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia worldwide. Omega-3 fatty acids (n-3-PUFA) are essential to normal neural development and function. Souvenaid®, a medical supplement that contains n-3-PUFA's: eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA), has emerged as an alternative, slowing cognitive decline in AD patients. In this study, we investigated the effect of dietary supplementation with n-3-PUFA, EPA, DHA, and Souvenaid® in AD patients.

AIM

This systematic review and meta-analysis aim to establish the relationship between n-3-PUFA, EPA, DHA, and Souvenaid® with cognitive effects, ventricular volume and adverse events in AD patients.

METHODS

A systematic search of randomized control trials (RCT), cohorts, and case-control studies was done in PubMed, Scopus, Web of Science, Cochrane, and Embase for AD adult patients with dietary supplementation with n-3-PUFA, EPA, DHA, or Souvenaid® between 2003 and 2024.

RESULTS

We identified 14 studies with 2766 subjects aligned with our criteria. Most publications described positive cognitive outcomes from supplements (58%). The most common adverse events reported were gastrointestinal symptoms. CDR scale showed reduced progression of cognitive decline (SMD = -0.4127, 95% CI: [-0.5926; -0.2327]), without subgroup differences between different dietary supplement interventions. ADCS-ADL, MMSE, ADAS-cog, adverse events, and ventricular volume did not demonstrate significant differences. However, Souvenaid® showed a significant negative effect (SMD = -0.3593, 95% CI: -0.5834 to -0.1352) in ventricular volumes.

CONCLUSIONS

The CDR scale showed reduced progression of cognitive decline among patients with n-3-PUFA supplemental interventions, with no differences between different n-3-PUFA supplements.

LC/MS-Based Metabolomics Reveals Chemical Variations of Two Broccoli Varieties in Relation to Their Anticholinesterase Activity: In vitro and In silico Studies

Broccoli is commonly consumed as food and as medicine. However, comprehensive metabolic profiling of two broccoli varieties, Romanesco broccoli (RB) and purple broccoli (PB), in relation to their anticholinergic activity has not been fully disclosed. A total of 110 compounds were tentatively identified using UPLC-Q-TOF-MS metabolomics. Distinctively different metabolomic profiles of the two varieties were revealed by principal component analysis (PCA). Furthermore, by volcano diagram analysis, it was found that PB had a significantly higher content of phenolic acids, flavonoids, and glucosinolates, indicating the different beneficial health potentials of PB that demonstrated higher antioxidant and anticholinergic activities. Moreover, Pearson's correlation analysis revealed 18 metabolites, mainly phenolic and sulfur compounds, as the main bioactive. The binding affinity of these biomarkers to the active sites of acetyl- and butyryl-cholinesterase enzymes was further validated using molecular docking studies. Results emphasize the broccoli significance as a functional food and nutraceutical source and highlight its beneficial effects against Alzheimer's disease.

Medicinal herbal remedies in neurodegenerative diseases: an update on antioxidant potential

It has been widely documented that medicinal herbal remedies are effective, have fewer side effects than conventional medicine, and have a synergistic effect on health collaborations in the fight against complicated diseases. Traditional treatments for neurological problems in ancient times sometimes involved the use of herbal remedies and conventional methods from East Asian countries including India, Japan, China, and Korea. We collected and reviewed studies on plant-derived neuroprotective drugs and tested them in neurotoxic models. Basic research, preclinical and clinical transgene research can benefit from in silico, in vitro, and in vivo investigations. Research, summaries of the extracts, fractions, and herbal ingredients were compiled from popular scientific databases, which were then examined according to origin and bioactivity. Given the complex and varied causes of neurodegeneration, it may be beneficial to focus on multiple mechanisms of action and a neuroprotection approach. This approach aims to prevent cell death and restore function to damaged neurons, offering promising strategies for preventing and treating neurodegenerative diseases. Neurodegenerative illnesses can potentially be treated with natural compounds that have been identified as neuroprotective agents. To gain deeper insights into the neuropharmacological mechanisms underlying the neuroprotective and therapeutic properties of naturally occurring antioxidant phytochemical compounds in diverse neurodegenerative diseases, this study aims to comprehensively review such compounds, focusing on their modulation of apoptotic markers such as caspase, Bax, Bcl-2, and proinflammatory markers. In addition, we delve into a range of efficacies of antioxidant phytochemical compounds as neuroprotective agents in animal models. They reduce the oxidative stress of the brain and have been shown to have anti-apoptotic effects. Many researches have demonstrated that plant extracts or bioactive compounds can fight neurodegenerative disorders. Herbal medications may offer neurodegenerative disease patients' new treatments. This may be a cheaper and more culturally appropriate alternative to standard drugs for millions of people with age-related NDDs.

Gut microbiome and brain transcriptome analyses reveal the effect of walnut oil in preventing scopolamine-induced cognitive impairment

Walnut Oil (WO) is recognized for its potential to improve cognition, but the mechanisms of its action related to improving cognitive impairment are not yet clear. In this study, the components of walnut oil were measured, and it was found that WO supplementation for 8 weeks could significantly prevent cognitive behavioral deficits and synaptic dysfunction induced by intraperitoneal injection of scopolamine (SCOP) in mice. By comparing and analyzing the changes in the hippocampal synaptic structure, oxidative stress, neurotransmitter fluctuations, brain transcriptome, inflammatory factors and gut microbiota in mice from different treatment groups, we observed a significant correlation between synaptic transmission genes, gut microbiota and neurotransmission in the WO supplemented group. It was found that WO supplementation could influence the secretion of neurotransmitters Ach and 5-HT by modulating the gut microbiota in vivo, thereby improving cognitive impairment through the central nervous system and hypothalamic-pituitary-adrenal (HPA) axis regulation.

Review of Eukaryote Cellular Membrane Lipid Composition, with Special Attention to the Fatty Acids

Biological membranes, primarily composed of lipids, envelop each living cell. The intricate composition and organization of membrane lipids, including the variety of fatty acids they encompass, serve a dynamic role in sustaining cellular structural integrity and functionality. Typically, modifications in lipid composition coincide with consequential alterations in universally significant signaling pathways. Exploring the various fatty acids, which serve as the foundational building blocks of membrane lipids, provides crucial insights into the underlying mechanisms governing a myriad of cellular processes, such as membrane fluidity, protein trafficking, signal transduction, intercellular communication, and the etiology of certain metabolic disorders. Furthermore, comprehending how alterations in the lipid composition, especially concerning the fatty acid profile, either contribute to or prevent the onset of pathological conditions stands as a compelling area of research. Hence, this review aims to meticulously introduce the intricacies of membrane lipids and their constituent fatty acids in a healthy organism, thereby illuminating their remarkable diversity and profound influence on cellular function. Furthermore, this review aspires to highlight some potential therapeutic targets for various pathological conditions that may be ameliorated through dietary fatty acid supplements. The initial section of this review expounds on the eukaryotic biomembranes and their complex lipids. Subsequent sections provide insights into the synthesis, membrane incorporation, and distribution of fatty acids across various fractions of membrane lipids. The last section highlights the functional significance of membrane-associated fatty acids and their innate capacity to shape the various cellular physiological responses.

Effect of local administration of eicosapentaenoic acid on the jaw-opening reflex in rats

Although eicosapentaenoic acid (EPA) application in vitro inhibits voltage-gated Na⁺ (Nav) channels in excitable tissues, the acute local effect of EPA on the jaw-opening reflex in vivo remains unknown. The aim of the present study was to determine whether local administration of EPA to adult male Wistar rats could attenuate the excitability of the jaw-opening reflex in vivo, including nociception. The jaw-opening reflex evoked by electrical stimulation of the tongue was recorded by a digastric muscle electromyogram (dEMG) in pentobarbital-anesthetized rats. The amplitude of the dEMG response was significantly increased in proportion to the electrical stimulation intensity (1×-5× threshold). At 3×, local administration of EPA dose-dependently inhibited the dEMG response, lasting 60 min, with maximum inhibition observed within approximately 10 min. The mean magnitude of dEMG signal inhibition by EPA was almost equal to that observed with a local anesthetic, 1% lidocaine, and with a half dose of lidocaine plus a half dose of EPA. These findings suggest that EPA attenuates the jaw-opening reflex, possibly by blocking Nav channels of primary nerve terminals, and strongly support the idea that EPA is a potential therapeutic agent and complementary alternative medicine for the prevention of acute trigeminal nociception.

DHA Ameliorates Cognitive Ability, Reduces Amyloid Deposition, and Nerve Fiber Production in Alzheimer’s Disease

Background

The etiology of Alzheimer’s disease (AD) is very complex. Docosahexaenoic acid (DHA) is important in cognitive ability and nervous system development. A limited number of studies have evaluated the efficacy of DHA in the treatment of AD.

Introduction

We detected neurofibrillary tangles (NFT) in the hippocampus and cortex of transgenic mice brain through silver glycine staining. We determined the activity of neurons by staining Nissl bodies, used liquid NMR to detect metabolites in the brain, and functional magnetic resonance imaging results to observe the connection signal value between brain regions.

Materials and Methods

We fed 3-month-old APP/PS1 double transgenic mice with DHA mixed feeds for 4 months to assess the effects of DHA on cognitive ability in AD mice through the Morris water maze and open field tests. To evaluate its effects with AD pathology, continuous feeding was done until the mice reached 9 months of age.

Results

Compared to AD mice, escape latency significantly decreased on the fifth day while swimming speed, target quadrant stay time, and the crossing number of platforms increased by varying degrees after DHA treatment. Brain tissue section staining revealed that DHA significantly reduced Aβ and nerve fibers in the brain of AD mice.

Conclusion

DHA significantly reduced the deposition of Aβ in the brain and inhibited the production of nerve fibers, thereby increasing cognitive abilities in AD mice. In addition, DHA suppressed blood lipid levels, and restored uric acid and urea levels, implying that DHA is a potential therapeutic option for early AD.

Methylxanthines Induce a Change in the AD/Neurodegeneration-Linked Lipid Profile in Neuroblastoma Cells

Alzheimer's disease (AD) is characterized by an increased plaque burden and tangle accumulation in the brain accompanied by extensive lipid alterations. Methylxanthines (MTXs) are alkaloids frequently consumed by dietary intake known to interfere with the molecular mechanisms leading to AD. Besides the fact that MTX consumption is associated with changes in triglycerides and cholesterol in serum and liver, little is known about the effect of MTXs on other lipid classes, which raises the question of whether MTX can alter lipids in a way that may be relevant in AD. Here we have analyzed naturally occurring MTXs caffeine, theobromine, theophylline, and the synthetic MTXs pentoxifylline and propentofylline also used as drugs in different neuroblastoma cell lines. Our results show that lipid alterations are not limited to triglycerides and cholesterol in the liver and serum, but also include changes in sphingomyelins, ceramides, phosphatidylcholine, and plasmalogens in neuroblastoma cells. These changes comprise alterations known to be beneficial, but also adverse effects regarding AD were observed. Our results give an additional perspective of the complex link between MTX and AD, and suggest combining MTX with a lipid-altering diet compensating the adverse effects of MTX rather than using MTX alone to prevent or treat AD.

Consensus mutagenesis and computational simulation provide insight into the desaturation catalytic mechanism for delta 6 fatty acid desaturase

Fatty acid desaturase (FADS) generates double bond at a certain position of the corresponding polyunsaturated fatty acids (PUFAs) with high selectivity, the enzyme activity and PUFAs products of which are essential to biological systems and are associated with a variety of physiological diseases. Little is known about the structure of FADSs and their amino acid residues related to catalytic activities. Identifying key residues of Micromonas pusilla delta 6 desaturase (MpFADS6) provides a point of departure for a better understanding of desaturation. In this study, conserved amino acids were anchored through gene consensus analysis, thereby generating corresponding variants by site-directed mutagenesis. To achieve stable and high-efficiency expression of MpFADS6 and its variants in Saccharomyces cerevisiae, the key points of induced expression were optimized. The contribution of conserved residues to the function of enzyme was determined by analyzing enzyme activity of the variants. Molecular modeling indicated that these residues are essential to catalytic activities, or substrate binding. Mutants MpFADS6_[Q409R] and MpFADS6_[M242P] abolished desaturation, while MpFADS6_[F419V] and MpFADS6_[A374Q] significantly reduced catalytic activities. Given that certain residues have been identified to have a significant impact on MpFADS6 activities, it is put forward that histidine-conserved region III of FADS6 is related to electronic transfer during desaturation, while histidine-conserved regions I and II are related to desaturation. These findings provide new insights and methods to determine the structure, mechanism and directed transformation of membrane-bound desaturases.

Intake of Docosahexaenoic Acid-Enriched Milk Beverage Prevents Age-Related Cognitive Decline and Decreases Serum Bone Resorption Marker Levels

The pathogenic mechanism of dementia is still unknown, and the fundamental treatment remains to be established. Thus, there is growing interest in preventing dementia through diet. One of the functional ingredients attracting attention is docosahexaenoic acid. We conducted a 12-month, randomized, double-blind, placebo-controlled clinical trial in healthy elderly Japanese individuals with a Mini-Mental State Examination score of 28 or higher at baseline using a docosahexaenoic acid-enriched milk beverage containing 297 mg docosahexaenoic acid and 137 mg eicosapentaenoic acid. Consumption of a docosahexaenoic acid-enriched milk beverage increased the fatty acid levels of docosahexaenoic acid and eicosapentaenoic acid in erythrocyte membranes, which was the primary outcome of this study. Moreover, intake of this beverage prevented age-related cognitive decline and decreased serum bone resorption marker levels. Our data demonstrate that, even at a low dose, long-term daily intake of docosahexaenoic acid prevents dementia and may show beneficial effect on bone health.

Delineation of Neuroprotective Effects and Possible Benefits of AntioxidantsTherapy for the Treatment of Alzheimer's Diseases by Targeting Mitochondrial-Derived Reactive Oxygen Species: Bench to Bedside

Alzheimer's disease (AD) is considered the sixth leading cause of death in elderly patients and is characterized by progressive neuronal degeneration and impairment in memory, language, etc. AD is characterized by the deposition of senile plaque, accumulation of fibrils, and neurofibrillary tangles (NFTs) which are responsible for neuronal degeneration. Amyloid-β (Aβ) plays a key role in the process of neuronal degeneration in the case of AD. It has been reported that Aβ is responsible for the production of reactive oxygen species (ROS), depletion of endogenous antioxidants, increase in intracellular Ca²⁺ which further increases mitochondria dysfunctions, oxidative stress, release of pro-apoptotic factors, neuronal apoptosis, etc. Thus, oxidative stress plays a key role in the pathogenesis of AD. Antioxidants are compounds that have the ability to counteract the oxidative damage conferred by ROS. Therefore, the antioxidant therapy may provide benefits and halt the progress of AD to advance stages by counteracting neuronal degeneration. However, despite the beneficial effects imposed by the antioxidants, the findings from the clinical studies suggested inconsistent results which might be due to poor study design, selection of the wrong antioxidant, inability of the molecule to cross the blood-brain barrier (BBB), treatment in the advanced state of disease, etc. The present review insights into the neuroprotective effects and limitations of the antioxidant therapy for the treatment of AD by targeting mitochondrial-derived ROS. This particular article will certainly help the researchers to search new avenues for the treatment of AD by utilizing mitochondrial-derived ROS-targeted antioxidant therapies.

DUSP1 regulates hippocampal damage in epilepsy rats via ERK1/2 pathway

OBJECTIVE

To investigate the effects of DUSP1 on the hippocampal injury of young rats with epilepsy (EP) through mediating ERK1/2 signaling pathway.

METHODS

Young SD rats were selected and divided into Control, EP, EP + LV-GFP, EP + LV-DUSP1, EP + LV-siDUSP1, and EP + LV-siDUSP1 + U0126 groups. Morris Water Maze Test was used to detect the spatial learning and memory. Nissl staining and TUNEL staining were conducted and the inflammatory factors and oxidative stress-related indicators were also measured. Western blotting was utilized to detect the expression of DUSP1 and ERK1/2 pathway. EP cell model was constructed in vitro to verify the in vivo results.

RESULTS

Compared with Control group, young rats in EP group had decreased spatial learning and memory abilities and increased apoptotic rate and decreased number of Nissl positive cells. Besides, the up-regulated levels in inflammatory factors (IL-1β, IL-6), MDA content, and p-ERK1/2/ERK1/2 protein expression, as well as the down-regulated levels in DUSP1 protein expression and SOD content were also observed in EP rats. The EP rats treated with LV-DUSP1 showed obvious improvements regarding the above indicators, while those treated with LV-siDUSP1 had aggravated injury. But the effect of LV-siDUSP1 can be reversed by the treatment with ERK1/2 pathway inhibitor U0126. Further in vitro investigation verified the in vivo results.

CONCLUSION

DUSP1 may ameliorate the oxidative stress and inflammatory injury, as well as improve spatial learning and memory abilities via inhibiting ERK1/2 pathway, eventually playing protective roles in hippocampal injury of young rats with EP.

Behavioral, neuromorphological, and neurobiochemical effects induced by omega-3 fatty acids following basal forebrain cholinergic depletion in aged mice

Background

In recent years, mechanistic, epidemiologic, and interventional studies have indicated beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFA) against brain aging and age-related cognitive decline, with the most consistent effects against Alzheimer’s disease (AD) confined especially in the early or prodromal stages of the pathology.

In the present study, we investigated the action of n-3 PUFA supplementation on behavioral performances and hippocampal neurogenesis, volume, and astrogliosis in aged mice subjected to a selective depletion of basal forebrain cholinergic neurons. Such a lesion represents a valuable model to mimic one of the most reliable hallmarks of early AD neuropathology.

Methods

Aged mice first underwent mu-p75-saporin immunotoxin intraventricular lesions to obtain a massive cholinergic depletion and then were orally supplemented with n-3 PUFA or olive oil (as isocaloric control) for 8 weeks. Four weeks after the beginning of the dietary supplementation, anxiety levels as well as mnesic, social, and depressive-like behaviors were evaluated. Subsequently, hippocampal morphological and biochemical analyses and n-3 PUFA brain quantification were carried out.

Results

The n-3 PUFA treatment regulated the anxiety alterations and reverted the novelty recognition memory impairment induced by the cholinergic depletion in aged mice. Moreover, n-3 PUFA preserved hippocampal volume, enhanced neurogenesis in the dentate gyrus, and reduced astrogliosis in the hippocampus. Brain levels of n-3 PUFA were positively related to mnesic abilities.

Conclusions

The demonstration that n-3 PUFA are able to counteract behavioral deficits and hippocampal neurodegeneration in cholinergically depleted aged mice promotes their use as a low-cost, safe nutraceutical tool to improve life quality at old age, even in the presence of first stages of AD.

Δ6 fatty acid desaturases in polyunsaturated fatty acid biosynthesis: insights into the evolution, function with substrate specificities and biotechnological use

Δ6 fatty acid desaturases (FADS6) have different substrate specificities that impact the ratio of omega-6/omega-3 polyunsaturated fatty acids, which are involved in regulating multiple signalling pathways associated with various diseases. For decades, FADS6 with different substrate specificities have been characterized and the functions of these crucial enzymes have been investigated, while it remains enigmatic that the substrate specificities of FADS6 from various species have a huge difference. This review summarizes the substrate specificities of FADS6 in different species and reveals the underlying relationship. Further evaluation of biochemical properties has revealed that the FADS6 prefer linoleic acid that is more hydrophilic and stable. Domain-swapping and site-directed mutagenesis have been employed to delineate the regions and sites that affect the substrate specificities of FADS6. These analyses improve our understanding of the functions of FADS6 and offer information for the discovery of novel biological resources. KEY POINTS: • Outline of the excavation and identification of Δ6 fatty acid desaturases. • Overview of methods used to determine the pivotal resides of desaturases. • Application of substrate properties to generate specific fatty acids.

Comparison of pharmacokinetics of omega-3 fatty acid supplements in monoacylglycerol or ethyl ester in humans: a randomized controlled trial

Background

A diet low in omega-3 fatty acids (n-3 FA) results in low plasma concentrations of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the two main long chain n-3 FA. n-3 FA supplements on the market are esterified in triglycerides (TG) or ethyl ester (EE); the latter is absorbed less than other esterification forms. The objective of this study was to test and compare the pharmacokinetics of n-3 FA esterified in monoacylglycerides (MAG), a predigested form, with the EE form.

Methods

This study was a randomized, double-blind, crossover, controlled, clinical trial. Ten men and ten women between 18 and 60 years old were recruited. Participants received a single oral dose of 3 g of n-3 FA esterified in EE or MAG. Eleven blood samples were collected over 24 h post-dose. Plasma total lipids were extracted, methylated, and analyzed using gas chromatography.

Results

After receiving the MAG form, plasma EPA and DHA peaked at a concentration 3 and 2.5 times higher, respectively, than with the EE form. When provided in MAG form, n-3 FA plasma concentration during the absorption phase was on average 3–5 times higher than in EE form. When n-3 FAs were provided esterified in MAG, their concentration 24 h post-dose was higher than in EE. Males had a lower n-3 FA plasma concentration than females when n-3 FAs were provided in EE but there was no sexe difference when provided in MAG.

Conclusions

Plasma concentration of DHA and EPA was higher when provided in MAG than EE form.

Exploring the multimodal role of phytochemicals in the modulation of cellular signaling pathways to combat age-related neurodegeneration

Neurodegeneration is the progressive loss of neuronal structures and functions that lead to copious disorders like Alzheimer's (AD), Parkinson's (PD), Huntington's (HD), amyotrophic lateral sclerosis (ALS), and other less recurring diseases. Aging is the prime culprit for most neurodegenerative events. Moreover, the shared pathogenic factors of many neurodegenerative processes are inflammatory responses and oxidative stress (OS). Unfortunately, it is very complicated to treat neurodegeneration and there is no effective remedy. The rapid progression of the neurodegenerative diseases that exacerbate the burden and the concurrent absence of effective treatment strategies force the researchers to investigate more therapeutic approaches that ultimately target the causative factors of the neurodegeneration. Phytochemicals have great potential to exert their neuroprotective effects by targeting various mechanisms, such as OS, neuroinflammation, abnormal protein aggregation, neurotrophic factor deficiency, disruption in mitochondrial function, and apoptosis. Therefore, this review represents the molecular mechanisms of neuroprotection by multifunctional phytochemicals to combat age-linked neurodegenerative disorders.

Natural Compounds Rosmarinic Acid and Carvacrol Counteract Aluminium-Induced Oxidative Stress

Aluminum accumulation, glutathione (GSH) and malondialdehyde (MDA) concentrations as well as catalase (CAT) and superoxide dismutase (SOD) activities were determined in erythrocytes and brain and liver homogenates of BALB/c mice treated with Al3+ (7.5 mg/kg/day (0.15 LD50) as AlCl3 (37.08 mg/kg/day), whereas HCl (30.41 mg/kg/day) was used as Cl- control, the treatments were performed for 21 days, i.p., in the presence and absence of rosmarinic acid (0.2805 mg/kg/day (0.05 LD50), 21 days, i.g.) or carvacrol (0.0405 mg/kg/day (0.05 LD50), 21 days, i.g.). The treatment with AlCl3 increased GSH concentration in erythrocytes only slightly and had no effect on brain and liver homogenates. Rosmarinic acid and carvacrol strongly increased GSH concentration in erythrocytes but decreased it in brain and liver homogenates. However, AlCl3 treatment led to Al accumulation in mice blood, brain, and liver and induced oxidative stress, assessed based on MDA concentration in the brain and liver. Both rosmarinic acid and carvacrol were able to counteract the negative Al effect by decreasing its accumulation and protecting tissues from lipid peroxidation. AlCl3 treatment increased CAT activity in mice brain and liver homogenates, whereas the administration of either rosmarinic acid or carvacrol alone or in combination with AlCl3 had no significant effect on CAT activity. SOD activity remained unchanged after all the treatments in our study. We propose that natural herbal phenolic compounds rosmarinic acid and carvacrol could be used to protect brain and liver against aluminum induced oxidative stress leading to lipid peroxidation.

Association of dietary ω-3 and ω-6 fatty acids intake with cognitive performance in older adults: National Health and nutrition examination Survey (NHANES) 2011-2014

Background

Current evidence on the association of dietary ω-3 and ω-6 fatty acids intake with cognitive performance is inconsistent. Therefore, the aim is to explore the association of dietary ω-3 and ω-6 fatty acids intake with cognitive performance in the U.S. noninstitutionalized population of older adults.

Methods

We used data from the National Health and Nutrition Examination Survey (NHANES) 2011–2014. Intakes of ω-3 and ω-6 fatty acids were obtained through two 24-h dietary recalls and were adjusted by energy. Cognitive performance was evaluated by the Consortium to Establish a Registry for Alzheimer’s disease (CERAD) Word Learning sub-test, Animal Fluency test and Digit Symbol Substitution Test (DSST). For each cognitive test, people who scored lower than the lowest quartile in each age group were defined as having low cognitive performance. Binary logistic regression and restricted cubic spline models were applied to evaluate the association of dietary ω-3 and ω-6 fatty acids intake with cognitive performance.

Results

A total of 2496 participants aged 60 years or older were included. In the full-adjusted model, the odds ratios (ORs) with 95% confidence interval (CI) of CERAD test score, Animal Fluency test score and DSST test score were 0.58 (0.38–0.88), 0.68 (0.47–0.99) and 0.59 (0.37–0.92) for the highest versus lowest tertile of dietary ω-3 fatty acids intake, respectively; the ORs with 95% CI of CERAD test score, Animal Fluency test score and DSST test score were 0.48 (0.31–0.75), 0.60 (0.40–0.92) and 0.50 (0.34–0.75) for the highest versus lowest tertile of dietary ω-6 fatty acids intake, respectively. The association between ω-6: ω-3 ratio and cognitive performance was not statistically significant in three tests. In dose-response relationship analysis, L-shaped associations were apparent for ω-3 and ω-6 fatty acids intake with CERAD test score, Animal Fluency test score and DSST test score.

Conclusions

Dietary ω-3 and ω-6 fatty acids intake might be inversely associated with low cognitive performance.

Multidomain intervention and/or omega-3 in nondemented elderly subjects according to amyloid status

INTRODUCTION

The Multidomain Alzheimer Preventive Trial (MAPT) assessed the efficacy of omega-3 fatty acid supplementation, a multidomain intervention (MI), or a combination of both on cognition. Impact according to cerebral amyloid status was evaluated by PET scan.

METHODS

Participants were nondemented and had memory complaints, limitation in one instrumental activity of daily living, or slow gait. The primary outcome was a change from baseline in 36 months measured with a cognitive composite Z score.

RESULTS

No effect was observed on cognition in the negative amyloid group (n = 167). In the positive amyloid group (n = 102), we observed a difference of 0.708 and 0.471 in the cognitive composite score between the MI plus omega-3 fatty acid group, the MI alone group, and the placebo group, respectively.

DISCUSSION

MI alone or in combination with omega-3 fatty acids was associated with improved primary cognitive outcome in subjects with positive amyloid status.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01513252.

SQSTM1/p62 is involved in docosahexaenoic acid-induced cellular autophagy in glioblastoma cell lines

Docosahexaenoic acid (DHA) is the most abundant n-3 polyunsaturated fatty acid in the human brain and works as an anticancer agent to induce cell cycle arrest and apoptosis in glioblastoma multiforme (GBM) cell lines. However, little is known about the connection between DHA and autophagy in GBM cells. We found that high-dose DHA caused cellular autophagy in cultured U251 and U118 GBM cell lines, but there was no effect with a low dose. Moreover, after treatment with a high dose of DHA at 12, 24, and 48 h, the protein expression of SQSTM1/p62 decreased in DHA-treated U251 cells at 12 and 24 h, but increased at 48 h, while in DHA-treated U118 cells, the protein expression increased at all time points. Interestingly, the level of SQSTM1/p62 mRNA was elevated in both DHA-treated U251 and U118 cells at all time points, indicating that DHA activated SQSTM1/p62 transcription in both cell lines. Furthermore, downregulation of SQSTM1/p62 by siRNA attenuated DHA-induced cellular autophagy in both cell lines. This report confirms that high-dose DHA induces cellular autophagy in GBM cells, and demonstrates that SQSTM1/p62 acts as a regulator and participates in DHA-induced autophagy.

Membrane Lipid Composition: Effect on Membrane and Organelle Structure, Function and Compartmentalization and Therapeutic Avenues

Biological membranes are key elements for the maintenance of cell architecture and physiology. Beyond a pure barrier separating the inner space of the cell from the outer, the plasma membrane is a scaffold and player in cell-to-cell communication and the initiation of intracellular signals among other functions. Critical to this function is the plasma membrane compartmentalization in lipid microdomains that control the localization and productive interactions of proteins involved in cell signal propagation. In addition, cells are divided into compartments limited by other membranes whose integrity and homeostasis are finely controlled, and which determine the identity and function of the different organelles. Here, we review current knowledge on membrane lipid composition in the plasma membrane and endomembrane compartments, emphasizing its role in sustaining organelle structure and function. The correct composition and structure of cell membranes define key pathophysiological aspects of cells. Therefore, we explore the therapeutic potential of manipulating membrane lipid composition with approaches like membrane lipid therapy, aiming to normalize cell functions through the modification of membrane lipid bilayers.

The emerging role of omega-3 fatty acids as a therapeutic option in neuropsychiatric disorders

The prevalence of neurologic and psychiatric diseases has been increasing for decades and, given the moderate therapeutic efficacy and safety profile of existing pharmacological treatments, there is an urgent need for new therapeutic approaches. Nutrition has recently been recognized as an important factor for the prevention and treatment of neuropsychiatric disorders. The omega-3 polyunsaturated fatty acids (n-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) play critical roles in neuronal cell function and neurotransmission as well as inflammatory and immune reactions that are involved in neuropsychiatric disease states. A large number of experimental and epidemiological studies provide a strong basis for interventional clinical trials that assessed the clinical efficacy of n-3 PUFAs in various neurological and psychiatric disorders. Most of these trials found beneficial effects of dietary supplementation with EPA and DHA, and no serious safety concerns have emerged. This review gives an introduction to recent findings on the clinical efficacy of n-3 PUFAs in various neuropsychiatric disorders and the underlying biochemical mechanisms. In addition, the reader will be enabled to identify common methodological weaknesses of clinical studies on n-3 PUFAs, and suggestions for the design of future studies are given.

Clinical predictors of Alzheimer's disease progression

AIM

Rates of disease progression differ among patients with Alzheimer's disease (AD), but prognostic predictions remain a challenge. We carried out a clinic-based retrospective study to investigate the clinical factors for AD progression.

METHODS

The 748 AD patients, who attended our hospital for >1 year and were given the Mini-Mental State Examination (MMSE) at least three times, were divided into three groups according to the annual change rate of MMSE score (G): Aggravater group (G < -2), Stabler group (-2 ≤ G ≤ 2) and Improver group (2 < G). We compared the three groups on cognitive, affective and activities of daily living functions, response to medication, clinical fluctuations, serum levels of metabolic factors, and neuroimaging data.

RESULTS

We found no significant differences in age, sex, educational attainment or body mass index across the groups. The Aggravater group showed better baseline MMSE (P < 0.01) and Abe's behavioral and psychological symptoms of dementia (P < 0.01) scores than the Improver group, but its MMSE improvement after drug treatment was the worst among the three groups (P < 0.01 vs Stabler/Improver). Fluctuations in MMSE (P < 0.01), apathy scale (P < 0.05) and activities of daily living (P < 0.01) scores were smaller in the Improver group than in the Aggravater or Stabler groups. Serum docosahexaenoic acid levels tended to be lower (trend P < 0.05) and voxel-based specific regional analysis system for Alzheimer's disease Z-scores tended to be higher (trend P < 0.05) in the Improver group than in the Stabler or Aggravater groups.

CONCLUSIONS

Initial responses to medication, fluctuations in cognitive, affective and activities of daily living functions, serum docosahexaenoic acid levels, and medial temporal atrophy are clinical factors related to AD prognosis. Geriatr Gerontol Int 2018; 18: 929-936.

Reduced cognitive function, increased blood-brain-barrier transport and inflammatory responses, and altered brain metabolites in LDLr -/-and C57BL/6 mice fed a western diet

Recent work suggests that diet affects brain metabolism thereby impacting cognitive function. Our objective was to determine if a western diet altered brain metabolism, increased blood-brain barrier (BBB) transport and inflammation, and induced cognitive impairment in C57BL/6 (WT) mice and low-density lipoprotein receptor null (LDLr -/-) mice, a model of hyperlipidemia and cognitive decline. We show that a western diet and LDLr -/- moderately influence cognitive processes as assessed by Y-maze and radial arm water maze. Also, western diet significantly increased BBB transport, as well as microvessel factor VIII in LDLr -/- and microglia IBA1 staining in WT, both indicators of activation and neuroinflammation. Interestingly, LDLr -/- mice had a significant increase in ¹⁸F- fluorodeoxyglucose uptake irrespective of diet and brain ¹H-magnetic resonance spectroscopy showed increased lactate and lipid moieties. Metabolic assessments of whole mouse brain by GC/MS and LC/MS/MS showed that a western diet altered brain TCA cycle and β-oxidation intermediates, levels of amino acids, and complex lipid levels and elevated proinflammatory lipid mediators. Our study reveals that the western diet has multiple impacts on brain metabolism, physiology, and altered cognitive function that likely manifest via multiple cellular pathways.

[n-3 fatty acids and the maintenance of neuronal functions]

The functions of n-3 fatty acids are known to be diverse, and they play roles in cardiovascular and neuronal systems and in lipid metabolism. Docosahexaenoic acid (DHA), which is the most abundant n-3 fatty acid in the brain, is essential for the maintenance of brain functions throughout the human lifespan. Epidemiological studies have demonstrated that reduced n-3 fatty acid intake is closely associated with the onset of mental and neurological diseases such as brain developmental disorders, depression, and Alzheimer's disease. DHA is primarily involved in neurogenesis, synapse formation, neuronal differentiation, neurite outgrowth, maintenance of membrane fluidity, anti-inflammatory action, and antioxidant action. Its mechanism of action include: 1) the effects on ion channels and membrane bound receptors/enzymes achieved by changing membrane fluidity, as a cell membrane constituent, and 2) free DHA molecules, derived from the cell membrane that directly or metabolically, by conversion to protectin D1 and other molecules, indirectly regulates the gene expression and the activity of intracellular proteins. Although future studies are required, the supplementation of n-3 fatty acids such as DHA may suppress the deterioration of brain functions, delay the onset and progression of various mental/neurological diseases, and further improve the outcome of the neuronal diseases.

Nutrient intake, nutritional status, and cognitive function with aging

With the demographic aging of populations worldwide, diseases associated with aging are becoming more prevalent and costly to individuals, families, and healthcare systems. Among aging-related impairments, a decline in cognitive function is of particular concern, as it erodes memory and processing abilities and eventually leads to the need for institutionalized care. Accumulating evidence suggests that nutritional status is a key factor in the loss of cognitive abilities with aging. This is of tremendous importance, as dietary intake is a modifiable risk factor that can be improved to help reduce the burden of cognitive impairment. With respect to nutrients, there is evidence to support the critical role of several B vitamins in particular, but also of vitamin D, antioxidant vitamins (including vitamin E), and omega-3 fatty acids, which are preferentially taken up by brain tissue. On the other hand, high intakes of nutrients that contribute to hypertension, atherosclerosis, and poor glycemic control may have negative effects on cognition through these conditions. Collectively, the evidence suggests that considerable slowing and reduction of cognitive decline may be achieved by following a healthy dietary pattern, which limits intake of added sugars, while maximizing intakes of fish, fruits, vegetables, nuts, and seeds.

Lipids as central modulators of sensory TRP channels

The transient receptor potential (TRP) ion channel family is involved in a diversity of physiological processes including sensory and homeostatic functions, as well as muscle contraction and vasomotor control. Their dysfunction contributes to the etiology of several diseases, being validated as therapeutic targets. These ion channels may be activated by physical or chemical stimuli and their function is highly influenced by signaling molecules activated by extracellular signals. Notably, as integral membrane proteins, lipid molecules also modulate their membrane location and function either by direct interaction with the channel structure or by modulating the physico-chemical properties of the cellular membrane. This lipid-based modulatory effect is being considered an alternative and promising approach to regulate TRP channel dysfunction in diseases. Here, we review the current progress in this exciting field highlighting a complex channel regulation by a large diversity of lipid molecules and suggesting some diseases that may benefit from a membrane lipid therapy. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.

Impact of Omega-3 Fatty Acid Supplementation on Memory Functions in Healthy Older Adults

As the process of Alzheimer's disease (AD) begins years before disease onset, searching for prevention strategies is of major medical and economic importance. Nutritional supplementation with long-chain polyunsaturated omega-3 fatty acids (LC-n3-FA) may exert beneficial effects on brain structure and function. However, experimental evidence in older adults without clinical dementia is inconsistent, possibly due to low sensitivity of previously employed test batteries for detecting subtle improvements in cognition in healthy individuals. Here we used LOCATO, recently described as a robust and sensitive tool for assessing object-location memory (OLM) in older adults, to evaluate the impact of LC-n3-FA supplementation on learning and memory formation. In a double-blind placebo-controlled proof-of-concept study, 44 (20 female) cognitively healthy individuals aged 50-75 years received either LC-n3-FA (2,200 mg/day, n = 22) or placebo (n = 22) for 26 weeks. Before and after intervention, memory performance in the OLM-task (primary) was tested. As secondary outcome parameters, performance in Rey Auditory Verbal Learning Test (AVLT), dietary habits, omega-3-index, and other blood-derived parameters were assessed. Omega-3 index increased significantly in the LC-n3-FA group compared with the placebo group. Moreover, recall of object locations was significantly better after LC-n3-FA supplementation compared with placebo. Performance in the AVLT was not significantly affected by LC-n3-FA. This double-blind placebo-controlled proof-of-concept study provides further experimental evidence that LC-n3-FA exert positive effects on memory functions in healthy older adults. Our findings suggest novel strategies to maintain cognitive functions into old age.

Neuroprotective Effect of Several Phytochemicals and Its Potential Application in the Prevention of Neurodegenerative Diseases

The detrimental effects of oxidative stress and chronic neuroinflammation on neuronal cell death have been implicated in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD). The nutritional neuroscience is quickly growing, and phytochemicals or phytobioactive compounds such as curcumin, resveratrol, propolis, ginsenoside, and ω-3 polyunsaturated fatty acids (PUFAs) have been extensively applied to potential therapeutic purposes for numerous neurodegenerative diseases for their anti-oxidative and anti-inflammatory effects. However, their administration as food supplements in the daily diet of the elderly is normally a voluntary and less-organized behavior, indicating the uncertainty of therapeutic effects in this sporadic population; specifically, the effective physiological dosages and the real positive effects in preserving brain health have not yet been fully elucidated. In this review, we collect several lines of evidence on these compounds, which constitute a major type of nutraceuticals and are widely integrated into the daily anti-aging caring of elderly patients, and discuss the underlying anti-oxidative and anti-inflammatory mechanisms of these phytochemicals. In conclusion, we highlight the implications of these compounds in the prevention and treatment of geriatric diseases, and of the potential supplementation procedures used as a dietary therapeutic program in clinical nursing services for patients with neurodegenerative diseases or for the elderly in certain communities, which we hope will lead to more beneficial health outcomes with respect to brain function, innate immunity, and gastrointestinal function, as well as more economic and social benefits.

Dipotassium N-stearoyltyrosinate ameliorated pathological injuries in triple-transgenic mouse model of Alzheimer's disease

Recently, anandamide (AEA) analogues have been well recognized for its potent neuroprotective effects in counteracting the deterioration of Alzheimer's disease (AD) brains through multiple pathological processes. In our previous studies, dipotassium N-stearoyltyrosinate (NSTK), an AEA analogue synthesized by our laboratory was reported to exert significant efficacy through multiple interventions. Within this study, the amyloid precursor protein (APP)_SWE/presenilin-1 (PS1)_M146V/Tau_P301L mouse (3×Tg-AD) model was used to explore further the neuroprotective effects of NSTK and its underlying mechanisms. NSTK could increase spontaneous locomotor activity in the open field and low anxiety-like behavior in the elevated plus maze, and improve the spatial memory deficits in the Morris water maze. The biochemical analysis suggested that NSTK could decrease Aβ₄₂ deposition, abnormal tau aggregation, and the expressions of p-APP Thr668, PS1 and p-tau Ser202/Thr205 in the hippocampus of 3×Tg-AD mice. Consistently, NSTK could reduce the level of malondialdehyde, increase the activity of superoxide dismutase and catalase. Up-regulation of Bcl-2, and down-regulation of BAX, caspase-3 and inflammatory cytokines also occurred in the hippocampus of 3×Tg-AD mice after treatment with NSTK. Thus, NSTK could intervene in multiple pathological processes of AD and would be a drug candidate against AD.

Fatty acids and their therapeutic potential in neurological disorders

There is little doubt that we are what we eat. Fatty acid supplementation and diets rich in fatty acids are being promoted as ways to a healthier brain. Short chain fatty acids are a product of intestinal microbiota metabolism of dietary fibre; and their derivatives are used as an anti-convulstant. They demonstrated therapeutic potential in neurodegenerative conditions as HDAC inhibitors; and while the mechanism is not well understood, have been shown to lower amyloid β in Alzheimer's Disease in preclinical studies. Medium chain fatty acids consumed as a mixture in dietary oils can induce ketogenesis without the need for a ketogentic diet. Hence, this has the potential to provide an alternative energy source to prevent neuronal cell death due to lack of glucose. Long chain fatty acids are commonly found in the diet as omega fatty acids. They act as an anti-oxidant protecting neuronal cell membranes from oxidative damage and as an anti-inflammatory mediator in the brain. We review which agents, from each fatty acid class, have the most therapeutic potential for neurological disorders (primarily Alzheimer's disease, Parkinson's disease, Autism Spectrum Disorder as well as possible applications to traumatic brain injury), by discussing what is known about their biological mechanisms from preclinical studies.

Beneficial effects of dietary docosahexaenoic acid intervention on cognitive function and mental health of the oldest elderly in Japanese care facilities and nursing homes

AIM

We examined the effects of the administration of docosahexaenoic acid (DHA)-enriched meals on cognitive function in the oldest elderly with cognitive impairment, such as dementia, living in nursing homes, and on the improvement in caregiver burden at aging agencies.

METHODS

Participants in elderly care facilities and nursing homes (n = 75; 88.5 ± 0.6 years) were randomized in active and placebo groups. The active group had family-style meals containing an additional 1720 mg of docosahexaenoic acid per day for 12 months. At baseline, and after 6 and 12 months of intervention, cognitive function was assessed using Hasegawa's Dementia Scale-Revised and the Mini-Mental State Examination; mental health condition was assessed with the Apathy scale and the Zung Self-Rating Depression Scale; caregiver burden was evaluated using Zarit Burden Interview scores; and participants' serum biochemical factors were measured.

RESULTS

The participants were suggested to have dementia. After 12 months, the mean change in Mini-Mental State Examination subitem "Registration" score from baseline to month 12 showed a tendency to be greater in the active group than that in the placebo group. Mean changes in the Apathy scale from baseline to month 12 were less, and the changes in the Zung Self-Rating Depression Scale and the total Zarit Burden Interview scores showed a tendency to be lower in the active group than in the placebo group, respectively.

CONCLUSION

These results suggest that docosahexaenoic acid-enriched meals protect against age-related cognitive decline, and also improve apathy and caregiver burden for the oldest-elderly Japanese with cognitive impairment, such as dementia. Geriatr Gerontol Int 2017; 17: 330-337.

Oxidant/Antioxidant imbalance and the risk of Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia characterized by progressive loss of memory and other cognitive functions among older people. Senile plaques and neurofibrillary tangles are the most hallmarks lesions in the brain of AD in addition to neurons loss. Accumulating evidence has shown that oxidative stress-induced damage may play an important role in the initiation and progression of AD pathogenesis. Redox impairment occurs when there is an imbalance between the production and quenching of free radicals from oxygen species. These reactive oxygen species augment the formation and aggregation of amyloid-β and tau protein hyperphosphorylation and vice versa. Currently, there is no available treatments can modify the disease. However, wide varieties of antioxidants show promise to delay or prevent the symptoms of AD and may help in treating the disease. In this review, the role of oxidative stress in AD pathogenesis and the common used antioxidant therapies for AD will summarize.

The Association between Cerebral White Matter Lesions and Plasma Omega-3 to Omega-6 Polyunsaturated Fatty Acids Ratio to Cognitive Impairment Development

OBJECTIVE

Cerebral white matter hyperintensity (WMH) with magnetic resonance imaging (MRI) has a potential for predicting cognitive impairment. Serum polyunsaturated fatty acid (PUFA) levels are important for evaluating the extent of atherosclerosis. We investigated whether abnormal PUFA levels affected WMH grading and cognitive function in patients without significant cognitive impairment.

METHODS

Atherosclerotic risk factors, the internal carotid artery (ICA) plaque, and serum ratios of eicosapentaenoic to arachidonic acids (EPA/AA) and docosahexaenoic to arachidonic acids (DHA/AA) were assessed in 286 patients. The relationship among these risk factors, WMH, and cognitive function was evaluated using WMH grading and the Mini-Mental State Examination (MMSE).

RESULTS

The development of WMH was associated with aging, hypertension, ICA plaques, and a low serum EPA/AA ratio (<0.38, obtained as the median value) but was not related to dyslipidemia, diabetes, smoking, and a low serum DHA/AA ratio (<0.84, obtained as the median value). In addition, the MMSE score deteriorated slightly with the progression of WMH (29.7 ± 1.0 compared to 28.4 ± 2.1, P < 0.0001).

CONCLUSIONS

The progression of WMH was associated with a low serum EPA/AA ratio and accompanied minimal deterioration in cognitive function. Sufficient omega-3 PUFA intake may be effective in preventing the development of cognitive impairment.

Safety and lipid-altering efficacy of a new omega-3 fatty acid and antioxidant-containing medical food in men and women with elevated triacylglycerols

This randomized, double-blind, placebo-controlled multi-center trial investigated the lipid-altering effects of a medical food (PDL-0101) providing 1.8 g/d eicosapentaenoic acid; 12 mg/d astaxanthin, a marine algae-derived carotenoid; and 100 mg/d tocopherol-free gamma/delta tocotrienols enriched with geranylgeraniol, extracted from annatto, on triacylglycerols (TAG), other lipoprotein lipids, and oxidized low-density lipoprotein (LDL) in 102 subjects with TAG 150-499 mg/dL (1.69-5.63 mmol/L) and LDL cholesterol (LDL-C) ≥70 mg/dL (1.81 mmol/L). Compared to placebo, after eight weeks of treatment, PDL-0101 significantly reduced median TAG (-9.5% vs. 10.6%, p<0.001), while not significantly altering mean LDL-C (-3.0% vs. -8.0% for PDL-0101 and placebo, respectively, p=0.071), mean high-density lipoprotein cholesterol (~3% decrease in both groups, p=0.732), or median oxidized LDL concentrations (5% vs. -5% for PDL-0101 and placebo, respectively, p=0.112). These results demonstrate that PDL-0101 is an effective medical food for the management of elevated TAG.

Membrane lipid therapy: Modulation of the cell membrane composition and structure as a molecular base for drug discovery and new disease treatment

Nowadays we understand cell membranes not as a simple double lipid layer but as a collection of complex and dynamic protein-lipid structures and microdomains that serve as functional platforms for interacting signaling lipids and proteins. Membrane lipids and lipid structures participate directly as messengers or regulators of signal transduction. In addition, protein-lipid interactions participate in the localization of signaling protein partners to specific membrane microdomains. Thus, lipid alterations change cell signaling that are associated with a variety of diseases including cancer, obesity, neurodegenerative disorders, cardiovascular pathologies, etc. This article reviews the newly emerging field of membrane lipid therapy which involves the pharmacological regulation of membrane lipid composition and structure for the treatment of diseases. Membrane lipid therapy proposes the use of new molecules specifically designed to modify membrane lipid structures and microdomains as pharmaceutical disease-modifying agents by reversing the malfunction or altering the expression of disease-specific protein or lipid signal cascades. Here, we provide an in-depth analysis of this emerging field, especially its molecular bases and its relevance to the development of innovative therapeutic approaches.

Low-level mercury, omega-3 index and neurobehavioral outcomes in an adult US coastal population

BACKGROUND

Neurodevelopmental effects of omega-3 fatty acids and mercury from fish consumption have been characterized in children. In contrast, neurobehavioral outcomes associated with fish are not well studied in adults.

OBJECTIVE

This study of avid seafood consumers on Long Island (NY, USA) sought to define associations between mercury, seafood consumption, omega-3 fatty acids and neurobehavioral outcomes.

METHODS

A computer-based test system was used to assess neurobehavioral function. Blood total Hg (Hg) and omega-3 index were measured in 199 adult avid seafood eaters, who also completed the neurobehavioral assessment and an extensive food and fish frequency and demographic questionnaire.

RESULTS

For most of the outcomes considered, neither Hg nor omega-3 index was associated with neurobehavioral outcomes after adjustment for key confounding variables. Fish consumption, however, was associated with decreased odds of both self-reported fatigue (OR 0.85; 95 % CI 0.72, 1.01) and a constellation of neurologic symptoms (OR 0.79; 95 % CI 0.66, 0.96).

CONCLUSIONS

Results from our study provide little evidence that omega-3 fatty acids or Hg is associated with cognitive function in adult avid seafood consumers. Larger studies are needed to confirm our finding of associations between fish consumption and decreased self-reported fatigue and neurologic impairment.

n-3 fatty acids effectively improve the reference memory-related learning ability associated with increased brain docosahexaenoic acid-derived docosanoids in aged rats

We investigated whether a highly purified eicosapentaenoic acid (EPA) and a concentrated n-3 fatty acid formulation (prescription TAK-085) containing EPA and docosahexaenoic acid (DHA) ethyl ester could improve the learning ability of aged rats and whether this specific outcome had any relation with the brain levels of EPA-derived eicosanoids and DHA-derived docosanoids. The rats were tested for reference memory errors (RMEs) and working memory errors (WMEs) in an eight-arm radial maze. Fatty acid compositions were analyzed by GC, whereas brain eicosanoid/docosanoids were measured by LC-ESI-MS-MS-based analysis. The levels of lipid peroxides (LPOs) were measured by thiobarbituric acid reactive substances. The administration of TAK-085 at 300 mg·kg⁻¹day⁻¹ for 17 weeks reduced the number of RMEs in aged rats compared with that in the control rats. Both TAK-085 and EPA administration increased plasma EPA and DHA levels in aged rats, with concurrent increases in DHA and decreases in arachidonic acid in the corticohippocampal brain tissues. TAK-085 administration significantly increased the formation of EPA-derived 5-HETE and DHA-derived 7-, 10-, and 17-HDoHE, PD1, RvD1, and RvD2. ARA-derived PGE2, PGD2, and PGF2α significantly decreased in TAK-085-treated rats. DHA-derived mediators demonstrated a significantly negative correlation with the number of RMEs, whereas EPA-derived mediators did not exhibit any relationship. Furthermore, compared with the control rats, the levels of LPO in the plasma, cerebral cortex, and hippocampus were significantly reduced in TAK-085-treated rats. The findings of the present study suggest that long-term EPA+DHA administration may be a possible preventative strategy against age-related cognitive decline.

Senile plaques and cerebral amyloid angiopathy in an aged California sea lion (Zalophus californianus)

Senile plaques (SPs) and cerebral amyloid angiopathy (CAA) consisting of β-amyloid (Aβ) are major features in the brain of Alzheimer's disease (AD) patients and elderly humans and animals. In this study, we report the finding of SPs and CAA in an aged sea lion (30 years), which is the first demonstration of AD-related pathological changes in a marine animal. Histologically, SPs were observed at the cerebral cortex, most frequently at the frontal lobe, with two morphologically different types: the small round type and the large granular type. Only the small round SPs were positive for Congo red staining. The SPs were equally immunoreactive to Aβ40 and Aβ42 and were mainly composed of Aβ with an N-terminal pyroglutamate residue at position 3. Amyloid depositions at vessel walls were noted at the meninges and within the parenchyma. Interestingly, double immunofluorescence staining for Aβ40 and Aβ42 showed that the two subtypes were deposited segmentally in different parts of the vessel walls. The lesions observed in the sea lion suggest that Aβ deposition is widely present in various animal species, including marine mammals; however, the peculiar deposits similar to cotton wool plaques and the specific pattern of CAA are characteristic features of this animal.

Effect of docosahexaenoic acid and furan fatty acids on cytokinesis block micronucleus cytome assay biomarkers in astrocytoma cell lines under conditions of oxidative stress

Fatty acids from fish such as docosahexaenoic acid (DHA) are associated with improved brain function, whereas furan fatty acids (FFAs) also found in fish oil at low levels (1%) are thought to have antioxidant properties. Understanding their effects in astrocytes is important as these cells are responsible for maintaining healthy neurons via lipid homeostasis and distribution within the brain, and their decline with aging is a possible cause of dementia. We investigated the cytotoxic and genotoxic effects of DHA and FFA using the cytokinesis-block micronucleus cytome assay in in vitro cultures of U87MG (APOE ɛ3/ɛ3) and U118MG (APOE ɛ2/ɛ4) astrocytoma cell lines with and without a hydrogen peroxide (H2O2, 100 µM) challenge. U118MG was found to be more sensitive to the cytostatic, cytotoxic (i.e., apoptosis), and DNA damaging effects [micronuclei (MNi), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs)] of H2O2 (P < 0.01 and P < 0.001) when compared with U87MG. DHA at 100 µg/mL significantly affected cytostasis (P < 0.05) and increased DNA damage in the form of NPBs and MNi (P < 0.05) in both cell lines, whereas it decreased necrosis (P = 0.0251) in U87MG. Significant DHA-H2O2 interactions were observed for decreased necrosis (P = 0.0033) and DNA damage biomarkers (P < 0.0001) in the U87MG cell line and increased cytostasis (P < 0.0001) in the U118MG cell line. The effects of FFA also varied between the cell lines, with significant effects observed in decreased cytostasis (P = 0.0022) in the U87MG cell line, whereas increasing cytostasis (P = 0.0144) in the U118MG cell line. Overall, FFA exerted minimal effects on DNA damage biomarkers.