Preparation, Characterization, Evaluation of Neuroprotective Effect, and Related Mechanisms of Phosphatidylserine Emulsion in 5- and 12-Week Old Mice

Combination of Milk Polar Lipids and Casein Hydrolysate as a Healthy Emulsifier for Ice Cream

The demand for healthy ingredients in food products including ice cream, is continuously increasing. The potential of a combination of milk polar lipids (MPL) and casein hydrolysate (CH) to replace synthetic emulsifiers such as diacetyl tartaric acid esters of monoglycerides (DATEM), in ice cream production was investigated. Changes in particle size, emulsion stability, and interfacial tension of model emulsions (milk protein, casein:whey=8:2, w/v) were analyzed after the addition of MPL, CH, and their combination (MPL+CH). The use of MPL+CH reduced interfacial tension and increased αs- and β-casein displacement from the surface of cream layers compared to the addition of MPL alone. The addition of MPL+CH improved ice cream overrun to levels comparable to those of control ice cream containing DATEM (0.3%, w/v), without adversely affecting melt rate or microstructure. Confocal laser scanning microscopy revealed that ice cream prepared with MPL+CH formed a thick protein and coalesced fat layer on the surface of air cells that might help enhance overrun. These findings suggest that the combination of MPL (0.3%, w/v) and CH (0.03%, w/v) can be used as a potential emulsifier alternative to replace chemically synthesized emulsifiers such as DATEM.

Phase-Specific Immobilization of Phospholipase D as an Efficient Pickering Emulsion Interfacial Catalyst for Converting Antarctic Krill Oil Phospholipid

Phosphatidylserine (PS), a rare phospholipid in Antarctic krill oil (AKO) critical for brain development, can be produced from the abundant phosphatidylcholine (PC) using phospholipase D (PLD) in Pickering emulsion interfacial catalysis (PIC) systems. However, the exposure of PLD to organic solvent around the emulsion interface diminished PLD activity, limiting the conversion efficiency of PS. In this study, we proposed a strategy to fabricate a PIC system with high efficiency and stability by immobilizing PLD in a specific phase on the emulsion interface, based on investigating the effect of the interfacial microenvironment on PLD activity. Janus-poly(acrylic acid)/polystyrene (JPP) and Janus-polyethylenimine/octadecane (JPO) particles were fabricated as carriers to realize the specific-phase immobilization of PLD. The highest activity was observed when PLD was immobilized on the hydrophilic side of JPP (PLD@JPP(W)), 1.9-fold that of free PLD. The catalytic efficiency of PLD@JPP(W) was 1.7-fold that of free PLD, confirmed by the kcat/Km value enhancement. Immobilization on the hydrophilic side also enhanced the thermal stability of PLD. The half-lives of PLD were extended from 4 to 36 h at 40 °C and from 6 to 28 days at 4 °C. Importantly, PLD@JPP(W) showed excellent catalytic efficiency as a PIC system, achieving a PS productivity of 93% within a short time of 2 h at an enzyme dosage of 0.05 mg. PLD@JPP(W) exhibited a 3.6 times higher yield than free PLD in the production of PS from PC rich in Antarctic krill oil. The strategy in this work could also be applied to other lipases, providing a promising method for the efficient conversion of functional lipids.

Phosphatidylserine improves aging sepsis survival, modulates gut microbiome, and prevents sepsis-associated encephalopathy

Aged adults are prone to both short- and long-term complications following sepsis due to ineffective therapy. Phosphatidylserine (PS) is a membrane nutrient supplement known to enhance cognition and brain function, but its potential effects in treating sepsis are not well-documented. Our study aimed to explore the potential of PS in improving outcomes in sepsis and sepsis-associated encephalopathy (SAE). Middle-aged mice were administered PS for two months following induction of sepsis by lipopolysaccharides. The results indicated a significant increase in the survival rate of mice treated with PS after sepsis. Surviving mice underwent open field and shuttle box tests 45 days post-sepsis, revealing potential alleviation of neurobehavioral impairments due to PS pretreatment. Analysis at 60 days post-sepsis euthanasia showed reduced cleaved-caspase 3 in neurons and glial cell markers in the PS-treated group compared to the untreated sepsis group. Furthermore, PS administration effectively reduced proinflammatory cytokine gene expression in the hippocampus of mice with SAE, potentially inhibiting the TBK1/NLRP3/ASC signaling pathway. In the gut, PS pretreatment modulated β-diversity while maintaining jejunal morphology and colon ZO-1 expression, without significantly affecting α-diversity indices. Our findings suggest that PS administration improves survival rates, modulates the gut microbiome, preserves gut integrity, and ameliorates brain pathology in survived mice after sepsis. Importantly, these findings have significant implications for sepsis treatment and cognitive function preservation in aging individuals, providing new insights and sparking further interest and investigation into the potential of PS in sepsis treatment.

High-Yield Synthesis of Phosphatidylserine in a Well-Designed Mixed Micellar System

A sustainable enzymatic system is essential for efficient phosphatidylserine (PS) synthesis in industrial production. Conventional biphasic systems face challenges such as excessive organic solvent usage, enzyme-intensive processes, and increased costs. This study introduces a novel approach using chitin nanofibrils (ChNFs) as an immobilization material for phospholipase D (PLD) in a mixed micellar system stabilized by the food-grade emulsifier sodium deoxycholate (SDC). The immobilized enzyme, ChNF-chiA1, was quickly prepared in a one-step process, eliminating the need for purification. By optimizing the reaction conditions, including l-Ser concentration (1.0 M), SDC concentration (10 mM), reaction time (8 h), and enzyme dosage (1.0 U), a remarkable PS yield of 96.74% was achieved in the solvent-free mixed micellar system. The catalytic efficiency of ChNF-chiA1 surpassed that of the free PLD-chiA1 biphasic system by 6.0-fold. This innovative and green biocatalytic technology offers a reusable solution for the high-value enzymatic synthesis of phospholipids, providing a promising avenue for industrial applications.

Over the Counter Supplements for Memory: A Review of Available Evidence

In 2021, the Global Brain Health Supplement Industry Market size was valued at US$7.6 billion. It is predicted to increase to US$15.59 billion by 2030. Memory and its enhancement are a segment of the market that comprised the highest global revenue share in 2021. In the USA alone, dietary supplement sales reached US$18 billion in 2018. The US Food and Drug Administration (FDA) does not have the authority to approve dietary supplements' safety, effectiveness, or labeling before products go on the market. The FDA often does not even review supplements before they go to market. Supplement manufacturers are thus responsible for ensuring their products are safe and that their claims are truthful. An extensive review of current supplements on the market was performed by surveying memory products for sale at local and national pharmacies and grocery stores. A list of 103 supplements was compiled and the ingredients in these memory supplements were reviewed. The 18 most common ingredients in these supplements were identified. Each of the supplements included at least one of the 18 most common ingredients. Scientific data relative to these ingredients and their effect on memory was searched using PubMed and Cochrane library databases. Currently, there is no compelling evidence for use of apoaequorin, coenzyme Q10, coffee extracts, L-theanine, omega-3 fatty acids, vitamin B6, vitamin B9, or vitamin B12 supplementation for memory. On the other hand, there is some current evidence for memory benefit from supplementation with ashwagandha, choline, curcumin, ginger, Lion's Mane, polyphenols, phosphatidylserine, and turmeric. There are current studies with mixed results regarding the benefit of carnitine, gingko biloba, Huperzine A, vitamin D, and vitamin E supplementation for memory. Dietary supplements geared toward improving cognition are a billion-dollar industry that continues to grow despite lacking a solid scientific foundation for their marketing claims. More rigorous studies are needed relative to the long-term use of these supplements in homogenous populations with standardized measurements of cognition. Health care providers need to be aware of any and all supplements their older adult patients may be consuming and be educated about their side effects and interactions with prescription medications. Lastly, the FDA needs to take an active position relative to monitoring marketed supplements regarding safety, purity and claims of efficacy.

Mutation of the attractin gene impairs working memory in rats

OBJECTIVE

Attractin (ATRN) is a widely expressed member of the cell adhesion and guidance protein family in humans that is closely related to cellular immunity and neurodevelopment. However, while previous studies in our laboratory have confirmed the effect of ATRN mutations on long-term memory, its specific role and the molecular mechanism by which it influences spatial cognition are poorly understood.

METHODS

This study aimed to examine the effect of ATRN mutations on working memory in water maze with a novel ATRN-mutant rat generated by the CRISPR/Cas9 system; the mutation involved the substitution of the 505th amino acid, glycine (G), with cysteine (C), namely, a mutation from GGC to TGC. The changes in myelin basic protein (MBP) expression in rats were also analyzed with the western blot.

RESULTS

The ATRN-G505C(KI/KI) rats exhibited significant increases in the required latency and distance traveled to locate the escape platform in a Morris water maze test of working memory. In addition, the expression of MBP was reduced in ATRN-mutant rats, as shown in the western blot analysis.

CONCLUSION

Our results indicate that ATRN gene mutations may directly lead to the impairment of working memory in the water maze; this impairment may be due to the inhibition of MBP expression, which in turn affects the spatial cognition.