N-3 polyunsaturated fatty acids attenuate amyloid-beta-induced toxicity in AD transgenic Caenorhabditis elegans via promotion of proteasomal activity and activation of PPAR-gamma

Alzheimer's disease (AD) is a common neurodegenerative disease that causes progressive cognitive decline. A major pathological characteristic of AD brain is the presence of senile plaques composed of β-amyloid (Aβ), the accumulation of which induces toxic cascades leading to synaptic dysfunction, neuronal apoptosis, and eventually cognitive decline. Dietary n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are beneficial for patients with early-stage AD; however, the mechanisms are not completely understood. In this study, we investigated the effects of n-3 PUFAs on Aβ-induced toxicity in a transgenic AD Caenorhabditis elegans (C. elegans) model. The results showed that EPA and DHA significantly inhibited Aβ-induced paralytic phenotype and decreased the production of reactive oxygen species while reducing the levels of Aβ in the AD worms. Further studies revealed that EPA and DHA might reduce the accumulation of Aβ by restoring the activity of proteasome. Moreover, treating worms with peroxisome proliferator-activated receptor (PPAR)-γ inhibitor GW9662 prevented the inhibitory effects of n-3 PUFAs on Aβ-induced paralytic phenotype and diminished the elevation of proteasomal activity by n-3 PUFAs, suggesting that PPARγ-mediated signals play important role in the protective effects of n-3 PUFAs against Aβ-induced toxicity.

Long-Term Krill Oil Administration Alleviated Early Mild Cognitive Impairment in APP/PS1 Mice

SCOPE

Alzheimer's disease is an age-dependent neurodegenerative disorder. Mounting studies focus on the improvement of advanced cognitive impairment by dietary nutrients. Krill oil (KO), a rich source of DHA/EPA and astaxanthin, is effective in improving cognitive function. The study mainly investigates the protective effects of long-term KO administration on early cognitive impairment.

METHODS AND RESULTS

Results show that 2 months KO administration (50 and 100 mg kg-1 BW) can dramatically promote learning and memory abilities. Mechanism studies demonstrate that KO reduces amyloid β concentration by regulating the amyloidogenic pathway, inhibits neuro-inflammation via regulating TLR4-NLRP3 signaling pathway, and prevents neuron injure. KO supplementation also enhances gut barrier integrity, reduces serum lipopolysaccharide leakage, and alters the gut microbiota by reducing Helicobacteraceae, Lactobacillaceae proportion, increasing Dubosiella and Akkermansia relative abundance. Particularly, a significant increase of isovaleric acid, propionic acid, and acetic acid levels is observed after KO supplementation. Correlation analysis shows that short-chain fatty acids (SCFAs), gut microbiota, and cognitive function are strongly correlated.

CONCLUSIONS

The results reveal that KO relieves early mild cognitive impairment possibly for its role in mediating the gut microbiome-SCFAs-brain axis. Thus, KO may provide potential intervention strategies to prevent cognitive impairment in the early stages through the microbiota-gut-brain axis.

Decreased DHA-containing phospholipids in the neocortex of dementia with Lewy bodies are associated with soluble Aβ42 , phosphorylated α-synuclein, and synaptopathology

Docosahexaenoic acid (DHA) is an essential omega-3 polyunsaturated fatty acid implicated in cognitive functions by promoting synaptic protein expression. While alterations of specific DHA-containing phospholipids have been described in the neocortex of patients with Alzheimer's disease (AD), the status of these lipids in dementia with Lewy bodies (DLB), known to manifest aggregated α-synuclein-containing Lewy bodies together with variable amyloid pathology, is unclear. In this study, post-mortem samples from the parietal cortex of 25 DLB patients and 17 age-matched controls were processed for phospholipidomics analyses using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) platform. After controlling for false discovery rate, six out of the 46 identified putative DHA-phospholipid species were significantly decreased in DLB, with only one showing increase. Altered putative DHA-phospholipid species were subsequently validated with further LC-MS/MS measurements. Of the DHA-containing phospholipid (DCP) species showing decreases, five negatively correlated with soluble beta-amyloid (Aβ42) levels, whilst three also correlated with phosphorylated α-synuclein (all p < 0.05). Furthermore, five of these phospholipid species correlated with deficits of presynaptic Rab3A, postsynaptic neurogranin, or both (all p < 0.05). Finally, we found altered immunoreactivities of brain lysolipid DHA transporter, MFSD2A, and the fatty acid binding protein FABP5 in DLB parietal cortex. In summary, we report alterations of specific DCP species in DLB, as well as their associations with markers of neuropathological burden and synaptopathology. These results support the potential role of DHA perturbations in DLB as well as therapeutic targets.

Habitual intake of fat and sugar is associated with poorer memory and greater impulsivity in humans

The vicious cycle model of obesity suggests that repeated habitual intake of a diet high in fat and sugar (HFS) results in impairment in hippocampal function which in turn increases impulsive behaviours, making it harder to resist unhealthy diet choices. Evidence from studies with rodents consistently show switching to a HFS diet impairs performance on hippocampally-sensitive memory tasks. The limited literature in humans also suggest impaired memory and increased impulsivity related to higher habitual HFS intake. However, these changes in memory and impulsivity have been looked at independently. To investigate how these effects are inter-related, three experiments were conducted where relative HFS intake was related to measures of memory and impulsivity. In Experiment 1 (90 female participants), HFS was associated with higher scores on the Everyday Memory Questionnaire-revised (EMQ), and higher scores on the total, Attention (BISatt) and Motor (BISmot) sub-scales of the Barratt Impulsiveness Scale (BIS11). Experiment 2 (84 women and 35 men), replicated the association between HFS and EMQ, and also found HFS related to poorer performance on the hippocampally-sensitive 4 mountain (4MT) memory task. The association between HFS intake and the BISatt replicated, but there were no significant associations with other BIS11 measures or delay-discounting for monetary rewards. Experiment 3 (199 women and 87 men) replicated the associations between DFS and 4MT and EMQ, and also found an association with overall recall, but not response inhibition, from a Remembering Causes Forgetting task: HFS was also significantly associated with BIS total, BISatt and BISmot. In all three studies these associations remained when potential confounds (BMI, age, gender, hunger state, restrained and disinhibited eating) were controlled for. Mediation analysis found that the effect of HFS on memory at least part mediated the relationship between HFS and impulsivity in Experiments 1 and 3, but not 2. Overall these data provide some support for the vicious cycle model, but also suggest that trait impulsivity may be a risk factor for poor dietary choice.

A Comparative Study about the Neuroprotective Effects of DHA-Enriched Phosphatidylserine and EPA-Enriched Phosphatidylserine against Oxidative Damage in Primary Hippocampal Neurons

Nerve damage caused by accumulated oxidative stress is one of the characteristics and main mechanisms of Alzheimer's disease (AD). Previous studies have shown that phosphatidylserine (PS) rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) plays a significant role in preventing and mitigating the progression of AD. However, whether DHA-PS and EPA-PS can directly protect primary hippocampal neurons against oxidative damage has not been studied. Here, the neuroprotective functions of DHA-PS and EPA-PS against H₂O₂/t-BHP-induced oxidative damage and the possible mechanisms were evaluated in primary hippocampal neurons. It was found that DHA-PS and EPA-PS could significantly improve cell morphology and promote the restoration of neural network structure. Further studies showed that both of them significantly alleviated oxidative stress-mediated mitochondrial dysfunction. EPA-PS significantly inhibited the phosphorylation of ERK, thus playing an anti-apoptotic role, and EPA-PS significantly increased the protein expressions of p-TrkB and p-CREB, thus playing a neuroprotective role. In addition, EPA-PS, rather than DHA-PS could enhance synaptic plasticity by increasing the expression of SYN, and both could significantly reduce the expression levels of p-GSK3β and p-Tau. These results provide a scientific basis for the use of DHA/EPA-enriched phospholipids in the treatment of neurodegenerative diseases, and also provide a reference for the development of related functional foods.

Predictive metabolic networks reveal sex- and APOE genotype-specific metabolic signatures and drivers for precision medicine in Alzheimer's disease

INTRODUCTION

Late-onset Alzheimer's disease (LOAD) is a complex neurodegenerative disease characterized by multiple progressive stages, glucose metabolic dysregulation, Alzheimer's disease (AD) pathology, and inexorable cognitive decline. Discovery of metabolic profiles unique to sex, apolipoprotein E (APOE) genotype, and stage of disease progression could provide critical insights for personalized LOAD medicine.

METHODS

Sex- and APOE-specific metabolic networks were constructed based on changes in 127 metabolites of 656 serum samples from the Alzheimer's Disease Neuroimaging Initiative cohort.

RESULTS

Application of an advanced analytical platform identified metabolic drivers and signatures clustered with sex and/or APOE ɛ4, establishing patient-specific biomarkers predictive of disease state that significantly associated with cognitive function. Presence of the APOE ɛ4 shifts metabolic signatures to a phosphatidylcholine-focused profile overriding sex-specific differences in serum metabolites of AD patients.

DISCUSSION

These findings provide an initial but critical step in developing a diagnostic platform for personalized medicine by integrating metabolomic profiling and cognitive assessments to identify targeted precision therapeutics for AD patient subgroups through computational network modeling.

Longitudinal spatial mapping of lipid metabolites reveals pre-symptomatic changes in the hippocampi of Huntington's disease transgenic mice

In Huntington's disease (HD), a key pathological feature includes the development of inclusion-bodies of fragments of the mutant huntingtin protein in the neurons of the striatum and hippocampus. To examine the molecular changes associated with inclusion-body formation, we applied MALDI-mass spectrometry imaging and deuterium pulse labelling to determine lipid levels and synthesis rates in the hippocampus of a transgenic mouse model of HD (R6/1 line). The R6/1 HD mice lacked inclusions in the hippocampus at 6 weeks of age (pre-symptomatic), whereas inclusions were pervasive by 16 weeks of age (symptomatic). Hippocampal subfields (CA1, CA3 and DG), which formed the highest density of inclusion formation in the mouse brain showed a reduction in the relative abundance of neuron-enriched lipids that have roles in neurotransmission, synaptic plasticity, neurogenesis, and ER-stress protection. Lipids involved in the adaptive response to ER stress (phosphatidylinositol, phosphatidic acid, and ganglioside classes) displayed increased rates of synthesis in HD mice relative to WT mice at all the ages examined, including prior to the formation of the inclusion bodies. Our findings, therefore, support a role for ER stress occurring pre-symptomatically and potentially contributing to pathological mechanisms underlying HD.

Marine Sources of DHA-Rich Phospholipids with Anti-Alzheimer Effect

Alzheimer's disease (AD) is a complex and progressive disease, which affects millions of people around the world. Despite the many efforts over the years to find efficient therapeutics, there is no cure yet. Nonetheless, many compounds have been proven to decrease Alzheimer's symptoms. After a short overview of the hypotheses considered in AD drug development and the drugs approved for AD treatment, which lead to symptom release, we focus on the valorization of natural marine sources that decrease AD symptoms, particularly on docosahexaenoic acid (DHA), an important component in membrane phospholipids and the most abundant n-3 polyunsaturated fatty acids (PUFA) found in gray matter of the brain and in retina and on the DHA-containing phospholipids (DHA-PLs) present in marine sources, namely fish, krill, mollusks and in fisheries and aquaculture by-products. DHA-PLs' bioactivities are presented, namely their properties in anti-neurodegeneration, neuroinflammation, as anticancer agents, as well as their benefits to obesity and visual problems. Fisheries and aquaculture by-products are also highlighted as they have a high content of DHA and DHA-rich phospholipids, can be extracted by green methodologies and should be considered in a circular economy for a healthy sustainable future.

EPA-enriched plasmalogen attenuates the cytotoxic effects of LPS-stimulated microglia on the SH-SY5Y neuronal cell line

Microglia plays an important role in the production of inflammation in the central nervous system. Excessive nerve inflammation can cause neuronal damage and neurodegenerative disease. It has been shown that EPA-enriched ethanolamine plasmalogen (EPA-PlsEtn) significantly inhibited the expressions of inflammatory factors and suppressed neuronal loss in a rat model of Alzheimer's disease. However, whether EPA-PlsEtn protects against neuronal loss by inhibiting the activation of microglia is still not clear. Therefore, we examined the effect of PlsEtn on SH-SY5Y cells incubated by conditioned medium from LPS-induced BV2 cells as a neuroinflammation model. Results showed that pre-incubation of LPS-induced BV2 cells with PlsEtn significantly improved the viability of SH-SY5Y cells by reducing the early apoptosis. The increasing production of NO and TNF-α in BV2 cells was reversed by PlsEtn treatment, while the decreasing level of IL-10 was raised. Polarization toward M1 phenotype and activation of NLRP3 inflammasome pathways are attenuated significantly by pre-treatment of PlsEtn in LPS-induced BV2 cells. The study provides evidence for a positive effect of PlsEtn on neuroprotection and the inhibition of neuroinflammation, and PlsEtn may be explored as a potential functional ingredient with neuroprotection effects.

Effects of Dietary n-3 LCPUFA Supplementation on the Hippocampus of Aging Female Mice: Impact on Memory, Lipid Raft-Associated Glutamatergic Receptors and Neuroinflammation

Long-chain polyunsaturated fatty acids (LCPUFA), essential molecules whose precursors must be dietary supplied, are highly represented in the brain contributing to numerous neuronal processes. Recent findings have demonstrated that LCPUFA are represented in lipid raft microstructures, where they favor molecular interactions of signaling complexes underlying neuronal functionality. During aging, the brain lipid composition changes affecting the lipid rafts’ integrity and protein signaling, which may induce memory detriment. We investigated the effect of a n-3 LCPUFA-enriched diet on the cognitive function of 6- and 15-months-old female mice. Likewise, we explored the impact of dietary n-3 LCPUFAs on hippocampal lipid rafts, and their potential correlation with aging-induced neuroinflammation. Our results demonstrate that n-3 LCPUFA supplementation improves spatial and recognition memory and restores the expression of glutamate and estrogen receptors in the hippocampal lipid rafts of aged mice to similar profiles than young ones. Additionally, the n-3 LCPUFA-enriched diet stabilized the lipid composition of the old mice’s hippocampal lipid rafts to the levels of young ones and reduced the aged-induced neuroinflammatory markers. Hence, we propose that n-3 LCPUFA supplementation leads to beneficial cognitive performance by “rejuvenating” the lipid raft microenvironment that stabilizes the integrity and interactions of memory protein players embedded in these microdomains.

Elevated serum phosphatidylcholine (16:1/22:6) levels promoted by fish oil and vitamin D3 are highly correlated with biomarkers of non-alcoholic fatty liver disease in Chinese subjects

Phosphatidylcholine (16:1/22:6) was associated with improving inflammation and lipid metabolism.

Eicosapentaenoic acid (EPA) exhibits antioxidant activity via mitochondrial modulation

Reactive oxygen species (ROS) are mitochondrial respiration byproducts, the accumulation of which may cause oxidative damage and is associated with several chronic health problems. As an essential unsaturated fatty acid, eicosapentaenoic acid (EPA) provides various physiological functions; however, its exact regulatory role remains elusive. The current study aimed to address how EPA regulates cellular antioxidant capacity and the possible mechanisms of action. Upon 48 h of EPA treatment, the ROS levels of HepG2 cells were reduced by at least 40%; the total cellular antioxidant capacity was increased by approximately 50-70%, accompanied by enhanced activities and expression of major antioxidant enzymes. Furthermore, the mitochondrial membrane potential and the mitochondrial biogenesis were dramatically improved in EPA-treated cells. These data suggest that EPA improves cellular antioxidant capacity by enhancing mitochondrial function and biogenesis, which sheds light on EPA as a dietary complement to relieve the oxidative damage caused by chronic diseases.

Peony seed oil ameliorates neuroinflammation-mediated cognitive deficits by suppressing microglial activation through inhibition of NF-κB pathway in presenilin 1/2 conditional double knockout mice

Chronic neuroinflammation has been shown to exert adverse influences on the pathology of Alzheimer's disease (AD), associated with the release of abundant proinflammatory mediators by excessively activated microglia, causing synaptic dysfunction, neuronal degeneration, and memory deficits. Thus, the prevention of microglial activation-associated neuroinflammation is important target for deterring neurodegenerative disorders. Peony seed oil (PSO) is a new food resource, rich in α-linolenic acid, the precursor of long chain omega-3 polyunsaturated fatty acids, including docosahexaenoic acid and eicosapentaenoic acid, which exhibit anti-inflammatory properties by altering cell membrane phospholipid fatty acid compositions, disrupting lipid rafts, and inhibiting the activation of the proinflammatory transcription factor NF-κB. However, few studies have examined the anti-neuroinflammatory effects of PSO in AD, and the relevant molecular mechanisms remain unclear. Presenilin1/2 conditional double knockout (PS cDKO) mice display obvious AD-like phenotypes, such as neuroinflammatory responses, synaptic dysfunction, and cognitive deficits. Here, we assessed the potential neuroprotective effects of PSO against neuroinflammation-mediated cognitive deficits in PS cDKO using behavioral tests and molecular biologic analyses. Our study demonstrated that PSO suppressed microglial activation and neuroinflammation through the down-regulation of proinflammatory mediators, such as inducible NOS, COX-2, IL-1β, and TNF-α, in the prefrontal cortex and hippocampus of PS cDKO mice. Further, PSO significantly lessened memory impairment by reversing hyperphosphorylated tau and synaptic proteins deficits in PS cDKO mice. Importantly, PSO's therapeutic effects on cognitive deficits were due to inhibiting neuroinflammatory responses mediated by NF-κB signaling pathway. Taken together, PSO may represent an effective dietary supplementation to restrain the neurodegenerative processes of AD.

Combination of Lutein and DHA Alleviate H2O2 Induced Cytotoxicity in PC12 Cells by Regulating the MAPK Pathway

Docosahexaenoic acid (DHA) and lutein are important nutrients for brain health. Whether there were synergistic effects of DHA and lutein on the protection against neuronal cell damage induced by oxidative stress remained unclear. The present study was designed to investigate the synergistic effects of DHA and lutein against hydrogen peroxide (H₂O₂)-induced oxidative challenge in PC12 cells. PC12 cells were divided into different groups and received H₂O₂ (80 μM), lutein (20 μM)+H₂O₂ (80 μM), DHA (25 μM)+H₂O₂ (80 μM), and lutein (20 μM)+DHA (25 μM)+H₂O₂ (80 μM), respectively. The results indicated that pre-treatment of cells with lutein, DHA and DHA+lutein could significantly antagonize the H₂O₂-mediated growth inhibition and morphological changes in PC12 cells (p<0.05). Molecularlevel studies indicated that the DHA+lutein combination can significantly inhibit the mRNA expression of AMAD10 and BAX. Furthermore, Western blot analysis demonstrated that DHA+lutein synergistically inhibits the phosphorylation of JNK1/2. The results of the present study suggest that DHA and lutein in combination may be utilized as potent antioxidative compounds, with potential preventative or palliative effects on age-related neurodegenerative diseases.

Docosahexaenoic Acid-Acylated Astaxanthin Esters Exhibit Superior Renal Protective Effect to Recombination of Astaxanthin with DHA via Alleviating Oxidative Stress Coupled with Apoptosis in Vancomycin-Treated Mice with Nephrotoxicity

Prevention of acute kidney injury caused by drugs is still a clinical problem to be solved urgently. Astaxanthin (AST) and docosahexaenoic acid (DHA) are important marine-derived active ingredients, and they are reported to exhibit renal protective activity. It is noteworthy that the existing forms of AST in nature are mainly fatty acid-acylated AST monoesters and diesters, as well as unesterified AST, in which DHA is an esterified fatty acid. However, no reports focus on the different bioactivities of unesterified AST, monoesters and diesters, as well as the recombination of DHA and unesterified AST on nephrotoxicity. In the present study, vancomycin-treated mice were used to evaluate the effects of DHA-acylated AST monoesters, DHA-acylated AST diesters, unesterified AST, and the recombination of AST and DHA in alleviating nephrotoxicity by determining serum biochemical index, histopathological changes, and the enzyme activity related to oxidative stress. Results found that the intervention of DHA-acylated AST diesters significantly ameliorated kidney dysfunction by decreasing the levels of urea nitrogen and creatinine, alleviating pathological damage and oxidative stress compared to AST monoester, unesterified AST, and the recombination of AST and DHA. Further studies revealed that dietary DHA-acylated AST esters could inhibit the activation of the caspase cascade and MAPKs signaling pathway, and reduce the levels of pro-inflammatory cytokines. These findings indicated that the administration of DHA-acylated AST esters could alleviate vancomycin-induced nephrotoxicity, which represented a potentially novel candidate or therapeutic adjuvant for alleviating acute kidney injury.

Orally Administered DHA-Enriched Phospholipids and DHA-Enriched Triglyceride Relieve Oxidative Stress, Improve Intestinal Barrier, Modulate Inflammatory Cytokine and Gut Microbiota, and Meliorate Inflammatory Responses in the Brain in Dextran Sodium Sulfate Induced Colitis in Mice

SCOPE

Studies based on DHA/EPA supplementation in animal models of inflammatory bowel disease (IBD) reveal controversial results. It is speculated that different forms of DHA may explain the controversial results. Therefore, the effects of DHA-enriched phospholipids (DHA-PL) and DHA-enriched triglyceride (DHA-TG) on IBD are compared.

METHODS AND RESULTS

Male C57BL6/J mice are given DHA-PL and DHA-TG for 14 consecutive days, and receive ad libitum a 3.0% dextran sodium sulfate solution on the eighth day to establish IBD model. The results show that both DHA-PL and DHA-TG can reverse the colitis pathological process by decreasing the disease activity indexes (DAI), raising the colon length, suppressing the intestinal permeability, suppressing the oxidative stress, down-regulating pro-inflammatory factors, up-regulating anti-inflammatory factor in colon tissues. DHA-PL and DHA-TG also regulate the composition of gut microbiota via decreasing of the abundance Bacteroidetes and Firmicutes, and DHA-TG increases the abundance of Odoribacter. Importantly, DHA-PL and DHA-TG obviously attenuate the activation of microglia.

CONCLUSIONS

DHA-PL shows outstanding advantages in regulating oxidative stress, inflammatory responses, and intestinal barrier permeability. The current research indicates that the existence of DHA affects the improvement, DHA in phospholipid form could be a more effective choice for nutritional intervention to prevent and treat colitis.

Anti-aging effects of a functional food via the action of gut microbiota and metabolites in aging mice

Wushen (WS) is a mixed food containing 55 natural products that is beneficial to human health. This study aimed to reveal the preventive effect of WS on aging via a combined analysis of gut microbiome and metabolome. Senescence-accelerated mouse prone 8 (SAMP8) mice were used as aging model and senescence-accelerated mouse resistant 1 (SAMR1) mice as control. The mice were fed four diet types; control diet (for SAMR1 mice), standard diet (for SAMP8 mice, as SD group), WS diet, and fecal microbiota transplantation (FMT; transplanted from aging-WS mice). Our results showed that the weight, food intake, neurological function, and general physical conditions significantly improved in WS-fed mice compared to those fed with SD. The CA1 hippocampal region in WS-fed aged mice showed fewer shriveled neurons and increased neuronal layers compared to that of the SD group. WS-fed mice showed a decrease in malondialdehyde and an increase in superoxide dismutase levels in the brain; additionally, IL-6 and TNF-α levels significantly decreased, whereas IL-2 levels and the proportion of lymphocytes, CD3+CD8+ T, and CD4+IFNγ+T cells increased in WS-fed mice. After fed with WS, the abundance of Ruminococcus and Butyrivibrio markedly increased, whereas Lachnoclostridium and Ruminiclostridium significantly decreased in the aging mice. In addition, 887 differentially expressed metabolites were identified in fecal samples, among these, Butyrivibrio was positively correlated with D-glucuronic acid and Ruminococcus was positively associated with 5-acetamidovalerate. These findings provide mechanistic insight into the impact of WS on aging, and WS may be a valuable diet for preventing aging.

A comparative study of the effects of phosphatidylserine rich in DHA and EPA on Aβ-induced Alzheimer's disease using cell models

Alzheimer's disease (AD) is an age-dependent, irreversible neurodegenerative disease, and one of the pathological features is amyloid-β (Aβ) deposition. Previous studies have shown that phosphatidylserine (PS) enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exhibited significant effects in preventing and alleviating the progress of AD. However, no studies have focused on the differences in the preventive effects on AD between EPA-PS and DHA-PS. Here, the effects of EPA-PS and DHA-PS on Aβ production, Aβ-induced neurotoxicity and Aβ clearance have been studied. The results show that DHA-PS significantly reduced Aβ production in CHO-APP/PS1 cells compared to EPA-PS. Moreover, both EPA-PS and DHA-PS significantly protected the primary hippocampal neurons against Aβ-induced toxicity by inhibiting the mitochondrial-dependent apoptotic pathway and phosphorylation of JNK and p38. Compared to DHA-PS, EPA-PS administration significantly improved the Aβ phagocytic capacity of BV2 cells. In addition, EPA-PS and DHA-PS significantly promoted the neurite outgrowth of primary hippocampal neurons. These findings might provide dietary guidance for the prevention of AD as well as a reference for the development of related functional foods.

Differences in oxidative susceptibilities between glycerophosphocholine and glycerophosphoethanolamine in dried scallop (Argopecten irradians) adductor muscle during storage: an oxidation kinetic assessment

BACKGROUND

Phospholipids, the main lipid component in marine shellfish, mainly comprise glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE). GPC and GPE in marine shellfish, especially scallop, carry n-3 long-chain polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), although different types of glycerophospholipids (GP) have different health benefits on human health. Moreover, different GP subclasses such as GPC and GPE have different oxidative susceptibilities in complex food systems. The present study compared the oxidative susceptibilities of GPC and GPE in dried scallop during storage by high-performance liquid chromatography-tandem mass spectrometry and kinetic models, and also investigated the effects of natural phenolic antioxidant on their susceptibilities.

RESULTS

The results showed that GPC and GPE molecular species (carrying EPA or DHA) contents in samples continuously reduced during storage at two different temperatures. The first-order kinetic model better reflected the changes of GPC and GPE molecular species (carrying EPA or DHA) in samples than the zero-order kinetic model during storage. According to the oxidation rate (k) obtained from first-order kinetic models, GPE possessed a greater oxidation rate than GPC during storage. Moreover, the results showed that antioxidants of bamboo leaves (AOB, polar polyphenolic antioxidants) significantly decreased the oxidation rates of GPC and GPE molecular species (carrying EPA or DHA) in samples during storage, and GPC could be more effectively protected by AOB compared to GPE.

CONCLUSION

The present study provides a practical method for accurately evaluating the oxidative susceptibility of different phospholipid classes in complex food systems. © 2020 Society of Chemical Industry.

The Potential for Phospholipids in the Treatment of Airway Inflammation: An Unexplored Solution

Asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) are major inflammatory respiratory diseases. Current mainstay therapy for asthma, and chronic obstructive pulmonary disease are corticosteroids, which have well-established side effect profiles. Phospholipids (PLs) are ubiquitous, diverse compounds with varying functions such as their structural role incell membrane, energy storage, and cell signaling.Recent advances in understanding PLs role as inflammatory mediators in the body as well as their widespread long-standing use as carrier molecules in drug delivery demonstrate the potential application of phospholipids in modulating inflammatory conditions. This review briefly explains the main mechanisms of inflammation in chronic respiratory diseases, currentanti-inflammatory treatments and areas of unmet need. The structural features, roles of endogenous and exogenous phospholipids, including their use as pharmaceutical excipients are reviewed. Current research on the immunomodulatory properties of PLs and their potentialapplication in inflammatory diseasesis the major section of this review. Considering the roles of PLs as inflammatory mediators and their safety profile established in pharmaceutical formulations, these small molecules demonstrate great potential as candidates in respiratory inflammation. Future studies need to focus on the immunomodulatory properties and the underlying mechanisms of phospholipids in respiratory inflammatory diseases.

Association Between Dietary Fish and PUFA Intake in Midlife and Dementia in Later Life: The JPHC Saku Mental Health Study

BACKGROUND

The relationship between midlife dietary habits and risk of dementia remains unclear.

OBJECTIVE

To investigate the association between dietary fish and n-3 polyunsaturated fatty acid (PUFA) consumption in midlife and risk of dementia in later life.

METHODS

This population-based cohort study assessed food frequency (average intake in 1995 and 2000) and cognition (2014-2015) in 1,127 participants (aged 45-64 in 1995). We used logistic regression analyses to calculate odds ratios (ORs) for dementia and mild cognitive impairment (MCI) diagnoses for consumption quartiles of fish, PUFA-rich fish, total n-3 PUFAs, total n-6 PUFAs, types of PUFAs, and n-3/n-6 PUFA ratio. Estimated ORs were adjusted for age; sex; education; smoking status; alcohol consumption frequency; physical activity; histories of cancer, myocardial infarction, and diabetes mellitus; and depression.

RESULTS

Significantly reduced risks of dementia over non-dementia (MCI plus cognitively normal) were observed in the second (OR = 0.43 (95% CI = 0.20-0.93)), third (OR = 0.22 (95% CI = 0.09-0.54)), and highest quartiles (OR = 0.39 (95% CI = 0.18-0.86)) for fish; the third (OR = 0.39 (95% CI = 0.16-0.92)) and highest quartiles (OR = 0.44 (95% CI = 0.19-0.98)) for eicosapentaenoic acid (EPA); the second (OR = 0.39 (95% CI = 0.18-0.84)), third (OR = 0.30 (95% CI = 0.13-0.70)), and highest quartiles (OR = 0.28 (95% CI = 0.12-0.66)) for docosahexaenoic acid (DHA); and the third (OR = 0.36 (95% CI = 0.16-0.85)) and highest quartiles (OR = 0.42 (95% CI = 0.19-0.95)) for docosapentaenoic acid (DPA).

CONCLUSION

High intake of fish in midlife might aid in preventing dementia.

Effect of different phosphatidylcholines on high fat diet-induced insulin resistance in mice

In this study, we systematically investigated the effect of different phosphatidylcholines on high fat diet-induced insulin resistance in mice.

Phosphatidylcholine Ameliorates LPS-Induced Systemic Inflammation and Cognitive Impairments via Mediating the Gut-Brain Axis Balance

Systemic inflammation will cause an imbalance in the steady state of the gut-brain axis. Phosphatidylcholine (PC) is a phospholipid found in egg yolk that has anti-inflammatory and antioxidant properties. The present research proved that PC supplementation (60 mg/kg body weight) for 35 days prevented inflammatory responses and behavioral disturbances in lipopolysaccharide (LPS)-induced mice. PC could regulate the expression of neurotrophic factors and synaptic proteins, which effectively alleviated the nerve damage and synaptic dysfunction caused by LPS. In addition, PC supplementation ameliorated gut barrier damage, altered gut genes, and improved gut health by modulating the cell adhesion molecule (CAM) pathway. Furthermore, PC remodeled the gut microbiome structure in the mice of the LPS group by increasing the relative abundance of Rikenellaceae and Lachnospiraceae. PC also increased short-chain fatty acid (SCFA) production in LPS-induced mice, which in turn ameliorated brain inflammatory responses. In conclusion, PC supplementation may be a nutritional strategy for the prevention of systemic inflammation via the gut-brain axis.

Inflammation: major denominator of obesity, Type 2 diabetes and Alzheimer's disease-like pathology?

Adipose tissue is an active metabolic organ that contributes to processes such as energy storage and utilization and to the production of a number of metabolic agents, such as adipokines, which play a role in inflammation. In this review, we try to elucidate the connections between peripheral inflammation at obesity and Type 2 diabetes and the central inflammatory process. Multiple lines of evidence highlight the importance of peripheral inflammation and its link to neuroinflammation, which can lead to neurodegenerative diseases such as dementia, Alzheimer's disease (AD) and Parkinson's disease. In addition to the accumulation of misfolded amyloid beta (Aβ) peptide and the formation of the neurofibrillary tangles of hyperphosphorylated tau protein in the brain, activated microglia and reactive astrocytes are the main indicators of AD progression. They were found close to Aβ plaques in the brains of both AD patients and rodent models of Alzheimer's disease-like pathology. Cytokines are key players in pro- and anti-inflammatory processes and are also produced by microglia and astrocytes. The interplay of seemingly unrelated pathways between the periphery and the brain could, in fact, have a common denominator, with inflammation in general being a key factor affecting neuronal processes in the brain. An increased amount of white adipose tissue throughout the body seems to be an important player in pro-inflammatory processes. Nevertheless, other important factors should be studied to elucidate the pathological processes of and the relationship among obesity, Type 2 diabetes and neurodegenerative diseases.

The effect of fish oil on social interaction memory in total sleep-deprived rats with respect to the hippocampal level of stathmin, TFEB, synaptophysin and LAMP-1 proteins

Fish oil (FO) is one of the richest natural sources of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). DHA is essential for brain functions and EPA has been approved for brain health. On the other hand, stathmin, TFEB, synaptophysin and LAMP-1 proteins are involved in synaptic plasticity, lysosome biogenesis and synaptic vesicles biogenesis. In this study, we aimed to investigate the effect of FO on social interaction memory in sleep-deprived rats with respect to level of stathmin, TFEB, synaptophysin and LAMP-1 in the hippocampus of rats. All rats received FO through oral gavage at the doses of 0.5, 0.75 and 1 mg/kg. The water box was used to induce total sleep deprivation (TSD) and the three-chamber paradigm test was used to assess social behavior. Hippocampal level of proteins was assessed using Western blot. The results showed, FO impaired social memory at the dose of 1 mg/kg in normal and sham groups. SD impaired social memory and FO did not restore this effect. Furthermore, FO at the dose of 0.75 mg/kg decreased social affiliation and social memory in all groups of normal rats, compared with related saline groups, and at the dose of 1 mg/kg impaired social memory for stranger 2 compared with saline group. In sham groups, FO at the dose of 1 mg/kg impaired social memory for stranger 2 compared with saline group. SD decreased hippocampal level of all proteins (except stathmin), and FO (1 mg/kg) restored these effects. In conclusion, FO negatively affects social interaction memory in rats.

Advances in exogenous docosahexaenoic acid-containing phospholipids: Sources, positional isomerism, biological activities, and advantages

In recent years, docosahexaenoic acid-containing phospholipids (DHA-PLs) have attracted much attention because of theirs unique health benefits. Compared with other forms of docosahexaenoic acid (DHA), DHA-PLs possess superior biological effects (e.g., anticancer, lipid metabolism regulation, visual development, and brain and nervous system biochemical reactions), more intricate metabolism mechanisms, and a stronger attraction to consumer. The production of DHA-PLs is hampered by several challenges associated with the limited content of DHA-PLs in natural sources, incomplete utilization of by-products, few microorganisms for DHA-PLs production, high cost, and complex process of artificial preparation of DHA-PLs. In this article, the sources, biological activities, and commercial applications of DHA-PLs were summarized, with intensive discussions on advantages of DHA-PLs over DHA, isomerism of DHA in phospholipids (PLs), and brain health. The excellent biological characteristics of DHA-PLs are primarily concerned with DHA and PLs. The metabolic fate of different DHA-PLs varies from the position of DHA in PLs to polar groups in DHA-PLs. Overall, well understanding of DHA-PLs about their sources and characteristics is critical to accelerate the production of DHA-PLs, economically enhance the value of DHA-PLs, and improve the applicability of DHA-PLs and the acceptance of consumers.

Green Nut Oil or DHA Supplementation Restored Decreased Distribution Levels of DHA Containing Phosphatidylcholines in the Brain of a Mouse Model of Dementia

Dementia is a major public health concern nowadays. Reduced levels of brain docosahexaenoic acid (DHA) and DHA-phosphatidylcholines (DHA-PCs) in dementia patients were reported previously. Recently, we have reported that supplementation of green nut oil (GNO) or DHA improves memory function and distribution levels of brain DHA in senescence accelerated mice P8 (SAMP8). GNO is extracted from Plukenetia volubilis seeds, and SAMP8 is a well-known model mouse of dementia. In this current study, we examined the results of GNO or DHA supplementation in the distribution levels of brain DHA-PCs in same model mouse of dementia using desorption electrospray ionization (DESI) mass spectrometry imaging (MSI). We observed significantly decreased distribution of brain DHA-PCs, PC (16:0_22:6), and PC (18:0_22:6) in SAMP8 mice compared to wild type mice, and GNO or DHA treatment restored the decreased distribution levels of PC (16:0_22:6) and PC (18:0_22:6) in the brain of SAMP8 mice. These results indicate that GNO or DHA supplementation can ameliorate the decreased distribution of brain DHA-PCs in dementia, and could be potentially used for the prevention and treatment of dementia.

Lipids Nutrients in Parkinson and Alzheimer's Diseases: Cell Death and Cytoprotection

Neurodegenerative diseases, particularly Parkinson’s and Alzheimer’s, have common features: protein accumulation, cell death with mitochondrial involvement and oxidative stress. Patients are treated to cure the symptoms, but the treatments do not target the causes; so, the disease is not stopped. It is interesting to look at the side of nutrition which could help prevent the first signs of the disease or slow its progression in addition to existing therapeutic strategies. Lipids, whether in the form of vegetable or animal oils or in the form of fatty acids, could be incorporated into diets with the aim of preventing neurodegenerative diseases. These different lipids can inhibit the cytotoxicity induced during the pathology, whether at the level of mitochondria, oxidative stress or apoptosis and inflammation. The conclusions of the various studies cited are oriented towards the preventive use of oils or fatty acids. The future of these lipids that can be used in therapy/prevention will undoubtedly involve a better delivery to the body and to the brain by utilizing lipid encapsulation.

Chemo-enzymatic synthesis, characterization, in vitro antioxidant capacity and oxidative stability studies of novel phosphatidylcholines with ω-3/ω-6 PUFAs and phenolic acids

Novel phosphatidylcholines containing PUFAs and phenolic acids were synthesized from egg phosphatidylcholine (PC), PUFAs (docosahexaenoic, arachidonic and linoleic acids) and phenolic acids (caffeic, ferulic and p-coumaric acids) as substrates. The structures of modified PCs were confirmed by spectral analysis and were evaluated for antioxidant activities. The modified PCs containing caffeic and ferulic acids exhibited excellent antioxidant activities compared with butylated hydroxytoluene (BHT) and α-tocopherol. The synthesized compounds were also evaluated for the oxidative stabilities in liposome and organic solvent. The modified PCs showed more oxidative stable compared with standard PUFA-PCs and PUFA-PCs + BHT. Results showed that the oxidative stability decreased with increasing degree of unsaturation in organic solvent whereas in liposomes, increased with increasing degree of unsaturation due to tight packed configuration. In this study, phenolic acids were found to render protections for PUFAs in modified PCs from oxidation. Modified PCs may have great potential for applications in food, cosmetic and pharmaceutical industries.

Eicosapentaenoic Acid-Enriched Phosphatidylcholine Mitigated Aβ1-42-Induced Neurotoxicity via Autophagy-Inflammasome Pathway

Recent studies indicated that neuroinflammation contributes to the exacerbation of Alzheimer's disease (AD) and plays an important role in AD. The NOD-like receptor protein 3 (NLRP3) inflammasome, which is an important component of innate immune system, is associated with a wide range of human central nervous system disorders, including AD. Most of the studies focus on the protective effects of docosahexaenoic acid (DHA) in AD, but eicosapentaenoic acid (EPA) has rarely been involved. Here, we investigate the effects of EPA in the forms of phosphatidylcholine (EPA-PC) and ethyl esters (EPA-EE) in improving Aβ1-42-induced neurotoxicity. The spatial memory ability and the biochemical changes in the hippocampus were measured, including glial cell activation, tumor necrosis factor α production, NLRP3 inflammasome activation, and autophagic flux. The present results showed that the AD rats were significantly protected from spatial memory loss by the supplementation (EPA + DHA = 60 mg/kg, i.g., 20 days) of EPA-PC, while EPA-EE showed no significant benefit. Further mechanism studies suggested that EPA-PC could inhibit Aβ-induced neurotoxicity by alleviating NLRP3 inflammasome activation and enhancing autophagy. These findings indicate that EPA could improve cognitive deficiency in Aβ1-42-induced AD rats via autophagic inflammasomal pathway and the bioactivity differs in its molecular form.

A Standardized Extract of Asparagus officinalis Stem (ETAS®) Ameliorates Cognitive Impairment, Inhibits Amyloid β Deposition via BACE-1 and Normalizes Circadian Rhythm Signaling via MT1 and MT2

The prevalence of cognitive impairments and circadian disturbances increases in the elderly and Alzheimer’s disease (AD) patients. This study investigated the effects of a standardized extract of Asparagus officinalis stem, ETAS^® on cognitive impairments and circadian rhythm status in senescence-accelerated mice prone 8 (SAMP8). ETAS^® consists of two major bioactive constituents: 5-hydroxymethyl-2-furfural (HMF), an abundant constituent, and (S)-asfural, a novel constituent, which is a derivative of HMF. Three-month-old SAMP8 male mice were divided into a control, 200 and 1000 mg/kg BW ETAS^® groups, while senescence-accelerated resistant mice (SAMR1) were used as the normal control. After 12-week feeding, ETAS^® significantly enhanced cognitive performance by an active avoidance test, inhibited the expressions of amyloid-beta precursor protein (APP) and BACE-1 and lowered the accumulation of amyloid β (Aβ) in the brain. ETAS^® also significantly increased neuron number in the suprachiasmatic nucleus (SCN) and normalized the expressions of the melatonin receptor 1 (MT1) and melatonin receptor 2 (MT2). In conclusion, ETAS^® enhances the cognitive ability, inhibits Aβ deposition and normalizes circadian rhythm signaling, suggesting it is beneficial for preventing cognitive impairments and circadian rhythm disturbances in aging.

Evaluation system construction and factor impact analysis of silica-gel adsorption to extract phytosterol glycosides from soybean lecithin powder

BACKGROUND

Soybean lecithin powders are good sources of phytosterol glucosides (PGs) containing acyl-sterylglycosides (ASGs) and sterylglucosides (SGs), but PG extraction from soybean lecithin powder is difficult due to the solubilizing property of phospolipids. To comprehensively utilize soybean lecithin resources, an evaluation system construction and factor impact analysis of PG extraction by silica-gel adsorption was investigated in this article.

RESULTS

With high-performance liquid chromatography (HPLC) as the main experimental analysis method, software such as SIMICA and SPSS were applied to construct an evaluation system of PG extraction. Different from scores plot in SIMICA for distinguishing samples in chloroform from others, the loading plot and binary variant correlation analysis of all indicators in PG extraction were brought to confirm four evaluation indicators containing PG purity, ASG recovery, SG recovery and phospholipid recovery. In the factor impact analysis, four times elution from silica-gel sediment was enough to achieve a PG product with least reagent waste, while SPW in petroleum ether at 50 mg mL-1 with 1:3 silica-gel dosage (lecithin/silica-gel, w/w) was then determined as the optimum of single factors.

CONCLUSION

All studies in this article were of great significance, as they laid foundations for research of PG extraction procedure, as well as PG industrial production, facilitating the comprehensive utilization of lecithin resources. © 2019 Society of Chemical Industry.

Dietary lysophosphatidylcholine-EPA enriches both EPA and DHA in the brain: potential treatment for depression

EPA and DHA protect against multiple metabolic and neurologic disorders. Although DHA appears more effective for neuroinflammatory conditions, EPA is more beneficial for depression. However, the brain contains negligible amounts of EPA, and dietary supplements fail to increase it appreciably. We tested the hypothesis that this failure is due to absorption of EPA as triacylglycerol, whereas the transporter at the blood-brain barrier requires EPA as lysophosphatidylcholine (LPC). We compared tissue uptake in normal mice gavaged with equal amounts (3.3 μmol/day) of either LPC-EPA or free EPA (surrogate for current supplements) for 15 days and also measured target gene expression. Compared with the no-EPA control, LPC-EPA increased brain EPA >100-fold (from 0.03 to 4 μmol/g); free EPA had little effect. Furthermore, LPC-EPA, but not free EPA, increased brain DHA 2-fold. Free EPA increased EPA in adipose tissue, and both supplements increased EPA and DHA in the liver and heart. Only LPC-EPA increased EPA and DHA in the retina, and expression of brain-derived neurotrophic factor, cyclic AMP response element binding protein, and 5-hydroxy tryptamine (serotonin) receptor 1A in the brain. These novel results show that brain EPA can be increased through diet. Because LPC-EPA increased both EPA and DHA in the brain, it may help in the treatment of depression as well as neuroinflammatory diseases, such as Alzheimer's disease.

Comparative studies of DHA-enriched phosphatidylcholine and recombination of DHA-ethyl ester with egg phosphatidylcholine on ameliorating memory and cognitive deficiency in SAMP8 mice

DHA-PLs (DHA-PC) could not be substituted by recombination of commercial fish oil with DHA-free PC in alleviating age-related memory loss and cognitive deficiency in SAMP8 mice.

Thein silicoandin vivoevaluation of puerarin against Alzheimer's disease

In silicomethods were used to screen the anti-AD effect of puerarin, further mutually verified by anin vivostudy.

Sex-Based Differences in Gut Microbiota Composition in Response to Tuna Oil and Algae Oil Supplementation in a D-galactose-Induced Aging Mouse Model

Our previous work indicated that a mixture of tuna oil and algae oil treatment in male mice effectively relieved D-galactose (D-gal)-induced aging and resulted in gut microbiota alterations, and that the best anti-aging effects were observed for a tuna oil to algae oil ratio of 1:2. However, the possibility of a sex-based difference in the anti-aging effect of the tuna oil and algae oil mixture or gut microbiota variation, has rarely been investigated. In this study, the anti-aging effect of an oil mixture (1:2) in male and female mice was measured, and oil treatment improved the learning and cognition of mice that were damaged by D-gal, increased the activities of anti-oxidative enzymes, and decreased the level of MDA, which acted as a hallmark of oxidative damage to lipids. Male mice showed better anti-aging effects than female mice with a specific oil mixture ratio, and the clinical drug donepezil showed a similar or better effect on aging alleviation than oil treatments in both sexes. On the other hand, the same oil treatment led to different gut microbiota composition alterations in male and female mice. Redundancy analysis (RDA) identified 31 and 30 key operational taxonomic units (OTUs) in the male and female mice, respectively, and only three of these OTUs overlapped. Moreover, the abundance of Lactobacillus and several probiotic-like butyric acid producers was higher in male mice than in female mice, whereas the abundance of some inflammation-related genera, such as Clostridium XlVa, was lower in male mice. In conclusion, this study indicated the sex-based differences related to the anti-aging effects of tuna oil and algae oil treatment are accompanied by sex-based differences in gut microbiota modulation.

Effects of Astaxanthin and Docosahexaenoic-Acid-Acylated Astaxanthin on Alzheimer's Disease in APP/PS1 Double-Transgenic Mice

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with the characteristics of senile plaques, neuroinflammation, neurofibrillary tangles, and destruction of synapse structure stability. Previous studies have verified the protective effects of astaxanthin (AST). However, whether synthesized docosahexaenoic-acid-acylated AST diesters (AST-DHA) could delay AD pathogenesis remains unclear. In the present study, APP/PSEN1 (APP/PS1) double-transgenic mice were administrated with AST and AST-DHA for 2 months. The results of radial 8-arm maze and Morris water maze tests showed that AST-DHA exerted more significant effects than AST in enhancing learning and memory levels of APP/PS1 mice. Further mechanical studies suggested that AST-DHA was superior to AST in regulating the parameters of oxidative stress, reducing tau hyperphosphorylation, suppressing neuroinflammation, and regulating inflammasome expression and activation in APP/PS1 mice. The findings suggested that AST-DHA attenuated cognitive disorders by reducing pathological features in APP/PS1 mice, suggesting that AST-DHA might be a potential therapeutic agent for AD.