Egg yolk phospholipids reverse scopolamine–induced spatial memory deficits in mice by attenuating cholinergic damage

Comparative Analysis of Egg Yolk Phospholipid Unsaturation and Its Impact on Neural Health in Alzheimer Disease Mice

The mechanism of egg yolk phosphatidylcholine (PC) in alleviating Alzheimer's disease (AD) has not yet been clear. The fatty acid composition of PC, especially the ratio of polyunsaturated fatty acids (PUFA), may be a critical determinant of their structural and functional roles. This study aimed to conduct a comparative analysis of the unsaturation levels of egg yolk PC and their impact on neurological health in a murine model of AD. The results showed that oral administration of high and low unsaturation PC (HUP, LUP) enhanced learning and memory abilities in AD mice, with the HUP intervention demonstrating superior efficacy compared to the LUP. Follow-up biochemical analysis of the brain tissue also suggested that HUP intervention effectively mitigated oxidative-stress damage and inhibited tau hyperphosphorylation in AD mice. Meanwhile, lipidomic analyses of the mouse hippocampus revealed that HUP intervention substantially increased the levels of phospholipids, such as PEt (phosphatidylethanol) and BisMePA (bis(methylthio)phenylacetic acid), which are recognized as vital components of neuronal cell membranes. Furthermore, HUP intervention markedly elevated the levels of phospholipids incorporating PUFAs in the hippocampus. These results revealed a mitigating role for unsaturated egg yolk PC in AD prevention and offer new insights into AD prevention from a lipidomic perspective.

Characterization of phospholipid profiles of egg yolks: Newly classified plasmalogens, distribution of polyunsaturated fatty acids, and the effects of dietary enrichment

Egg yolk phospholipids are commercially valuable products that are beneficial to human health. Previous research on phospholipids in egg yolk mainly focuses on phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), and fatty acid compositions, and neglects the esterification position and other bioactive phospholipids. This study found a total of 19 classes of phospholipids and 275 subclasses using lipidomics. The study firstly found that egg yolks were also rich in glucosylceramides, galactosylceramides, lactosylceramides, gangliosides, and plasmalogens with polyunsaturated fatty acids (PUFAs) at the high bioavailable sn-2 position. Docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), α-Linolenic acid (ALA), and arachidonic acid (ARA) were esterified at sn-1 position of PC and sn-2 position of PE, phosphatidyl inositol (PI) and phosphatidic acid (PA). Microalgae feeding contributed to the deposition of PUFAs at sn-2 position and increased the contents of plasmalogens. The results provided detail the phospholipid profiles of egg yolk to improve understanding of its nutrition.

Cognitive-enhancing effect of Cordia dichotoma fruit on scopolamine-induced cognitive impairment in rats: metabolite profiling, in vivo, and in silico investigations

Many plants are reported to enhance cognition in amnesic-animal models. The metabolite profile of Cordia dichotoma fruit methanolic extract (CDFME) was characterized by LC-QTOF-MS/MS, and its total phenolics content (TPC) and total flavonoids content (TFC) were determined. In parallel, its cognitive-enhancing effect on scopolamine (SCOP)-induced AD in rats was evaluated. The TPC and TFC were 44.75 ± 1.84 mg gallic acid equiv. g-1 sample and 5.66 ± 0.67 mg rutin equiv. g-1 sample, respectively. In total, 81 metabolites were identified, including phenolic acids, lignans, coumarins, amino acids, fatty acids, and their derivatives, fatty acid amides, polar lipids, terpenoids, and others. The most abundant metabolites identified were quinic acid, caffeoyl-4'-hydroxyphenyllactate, rosmarinic acid, and oleamide. CDFME (200 mg kg-1) was found to significantly enhance recognition memory in the novel object recognition test. Furthermore, it nearly corrected acetylcholinesterase (AChE), acetylcholine, noradrenaline, and dopamine hippocampal levels, which changed due to SCOP. Further in silico validation of the in vivo results was conducted, focusing on the most abundant metabolites. Molecular docking showed that rosmarinic acid, caffeoyl-4'-hydroxyphenyllactate, sebestenoid C, and sagerinic acid exhibited the greatest affinity for receptor binding against AChE. However, molecular dynamics and mechanics calculations clarified that the complex of caffeoyl-4'-hydroxyphenyllactate with AChE was the most stable one. This study represents the first comprehensive metabolite profiling of CDFME to assess its cognition-enhancing effect both in vivo and in silico. These results demonstrate that CDFME protects against SCOP-induced cognitive impairment. Thus, additional preclinical and clinical studies on CDFME may provide an attractive approach in pharmacotherapy and AD prophylaxis.

Selenium- and/or Zinc-Enriched Egg Diet Improves Oxidative Damage and Regulates Gut Microbiota in D-Gal-Induced Aging Mice

Eggs, with their high nutritional value, are great carriers for enriching nutrients. In this study, selenium- and/or zinc-enriched eggs (SZE) were obtained and their effects on ameliorating oxidative stress injury, alleviating cognitive impairment, and maintaining intestinal flora balance in a D-gal-induced aging mice model were investigated. As determined by the Y-maze test, SZE restored the learning and memory abilities and increased the Ach level and AChE activity of aging mice (p < 0.05). Meanwhile, supplementation of low-dose SZE increased antioxidant levels and decreased inflammation levels (p < 0.05). High-dose SZE increased anti-inflammatory levels but were less effective than low dose. Additionally, SZE maintained the intestinal flora balance and significantly increased the ratio of Firmicutes and Bacteroidota. Blautia, as a probiotic, was negatively correlated with pro-inflammatory factors and positively correlated with antioxidant levels (p < 0.05). These results suggest that SZE might improve organ damage and cognitive function by attenuating oxidative stress and inflammatory response and maintaining healthy gut flora.

Effects Of Biotin Deficiency On Short Term Memory: The Role Of Glutamate, Glutamic Acid, Dopamine And Protein Kinase A

Insufficient dietary biotin intake, biotinidase deficiency, drug-biotin interactions can cause biotin deficiency which may result in central nervous system dysfunctions. We hypothesized that biotin deficiency could disrupt learning and memory functions by altering glutamate, glutamine, dopamine levels and protein kinase A (PKA) activity in the hippocampus. Sixteen female and 4 male Wistar rats were mated and females were separated into 4 groups. Three pups were selected from each mother and a total of 48 pups were divided into the following experimental groups. NN group, normal diet in the prenatal and postnatal period. NB group, normal diet in the prenatal and a biotin-deficient diet in the postnatal period. BN group: biotin-deficient diet in the prenatal and a normal diet in the postnatal period, BB group: biotin-deficient diet in both the prenatal and postnatal period. Open Field, Y-Maze, Object Location, and Novel Object Recognition Tests were performed in all groups and rats were sacrificed. Glutamine, glutamate, dopamine levels and PKA activity were analyzed in the hippocampus. In the open field test, distance and velocity values of NB, BN and BB groups were decreased with respect to the NN group. Learning and memory functions of NB, BN and BB groups were found to be impaired in behavioral tests. Dopamine levels and PKA activity were also decreased in all rat pups fed with a biotin deficient diet. In conclusion, we demonstrated that biotin deficiency deteriorates short-term memory and locomotor activity. This impairment may relate to decreased dopamine levels and PKA activity in the hippocampus.

Compositional Features and Nutritional Value of Pig Brain: Potential and Challenges as a Sustainable Source of Nutrients

The goal of this study was to establish the nutritional value and compositional properties of the brains of crossbred pigs (Landrace-Large white-Duroc (LLD)), in order to realize the zero-waste concept and increase the use of by-products in the sustainable meat industry. Fat (9.25% fresh weight (fw)) and protein (7.25% fw) were the principal dry matters of pig brain, followed by carbohydrate and ash. Phospholipid and cholesterol had a 3:1 ratio. Pig brain had a red tone (L* = 63.88, a* = 5.60, and b* = 15.43) and a high iron content (66 mg/kg) due to a total heme protein concentration of 1.31 g/100 g fw. The most prevalent macro-element was phosphorus (14 g/kg), followed by potassium, sodium, calcium, and magnesium. Zinc, copper, and manganese were among the other trace elements discovered. The most prevalent nitrogenous constituents were alkali-soluble protein, followed by water-soluble protein, stromal protein, salt-soluble protein, and non-protein nitrogen. Essential amino acids were abundant in pig brain (44% of total amino acids), particularly leucine (28.57 mg/g protein), threonine, valine, and lysine. The total lipid, neutral, and polar lipid fractions of the pig brain had different fatty acid compositions. The largest amount was observed in saturated fatty acids (SFA), followed by monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Stearic acid and palmitic acid were the most common SFA. Oleic acid was the most prevalent MUFA, while docosahexaenoic acid was the most common PUFA. Thus, the pig brain can be used in food formulations as a source of nutrients.

AGLPM and QMDDQ peptides exert a synergistic action on memory improvement against scopolamine-induced amnesiac mice

This study aimed to explore the synergistic action of pentapeptides Gln-Met-Asp-Asp-Gln (QMDDQ) and Ala-Gly-Leu-Pro-Met (AGLPM) on memory improvement against scopolamine-induced impairment in mice compared to those of either peptide alone. In behavioral tests, the codelivery of QMDDQ and AGLPM was superior to the individual supplements of either peptide alone not only in enhancing the memory ability at training trials but also in recovering the memory impairment in scopolamine-induced amnesiac mice in test trials. Furthermore, combination treatment with QMDDQ and AGLPM could significantly reduce the acetylcholinesterase (AChE) level and increase the acetylcholine (ACh) level in the hippocampus, and noticeably improve the pathological morphology of the neuron cells in hippocampal regions CA1 and CA2 and dentate gyrus (DG). The findings indicated that the combination treatment with QMDDQ and AGLPM could improve the memory function by regulating the cholinergic system.