The role of C18 fatty acids in improving the digestion and retrogradation properties of highland barley starch.

In this study, five C18 fatty acids (FA) with different numbers of double bonds and configurations including stearic acid (SA), oleic acid (OA), elaidic acid (EA), linoleic acid (LA), and α-linolenic acid (ALA), were selected to prepare highland barely starch (HBS)-FA complexes to modulate digestibility and elaborate the underlying mechanism. The results showed that HBS-SA had the highest complex index (34.18 %), relative crystallinity (17.62 %) and single helix content (25.78 %). Furthermore, the HBS-C18 FA complexes were formed by EA (C18 FA with monounsaturated bonds) that had the highest R1047/1022 (1.0509) and lowest full width at half-maximum (FWHM, 20.85), suggesting good short-range ordered structure. Moreover, all C18 FAs could form two kinds of V-type complexes with HBS, which can be confirmed by the results of CLSM and DSC measurements, and all of them showed significantly lower digestibility. HBS-EA possessed the highest resistant starch content (20.17 %), while HBS-SA had the highest slowly digestible starch content (26.61 %). In addition, the inhibition of HBS retrogradation by fatty acid addition was further proven, where HBS-SA gel firmness (37.80 g) and aging enthalpy value were the lowest, indicating the most effective. Overall, compounding with fatty acids, especially SA, could be used as a novel way to make functional foods based on HBS.

Enzyme from Padina arborescens Holmes Synthesizes Parinaric Acid, a Conjugated Tetraenoic Fatty Acid, from α-Linolenic Acid.

Conjugated fatty acids have anticancer effects. Therefore, the establishment of a synthetic method for conjugated fatty acids is important for overcoming cancer. Here, we attempted to synthesize conjugated fatty acids using enzymes extracted from seaweeds containing these fatty acids. Lipids from 12 species of seaweeds from the seas around Japan were analyzed, and Padina arborescens Holmes was found to contain conjugated fatty acids. Then, we synthesized parinaric acid, a conjugated tetraenoic acid, from α-linolenic acid using the enzyme of P. arborescens. This method is expected to have a variety of potential applications for overcoming cancer.

Dietary combination of linseed and hazelnut skin as a sustainable strategy to enrich lamb with health promoting fatty acids.

This study investigated the effect of the inclusion of extruded linseed and hazelnut skin on fatty acid (FA) metabolism in finishing lambs. Forty lambs were divided into 4 groups and fed for 60 d with: a conventional cereal-based diet, or the same diet with 8% of extruded linseed, or 15% of hazelnut skin, or 4% of linseed plus 7.5% of hazelnut skin as partial replacement of maize. Dietary treatments did not affect growth performances, carcass traits, and ruminal fermentation. The combined effect of linseed and hazelnut skin enriched the intramuscular fat with health promoting FA. Particularly, increases in α-linolenic acid (3.75-fold), and very long-chain n-3 poly-unsaturated FA (+ 40%) were attributed to the supplementation with linseed, rich in α-linolenic acid. In addition, increases in rumenic (+ 33%), and vaccenic (+ 59%) acids were attributed to hazelnut skin tannins modulating ruminal biohydrogenation and accumulating intermediate metabolites. The simultaneous inclusion of linseed and hazelnut skin can be a profitable strategy for enriching the intramuscular fat of lambs with health promoting FA, without adverse effects on ruminal fermentation and animal performance.

Integrated Transcriptomic and Metabolomic Analysis Reveal the Dynamic Process of Bama Hemp Seed Development and the Accumulation Mechanism of α-Linolenic Acid and Linoleic Acid.

Bama County is a world-famous longevity county in the Guangxi Province, China. Bama hemp is a traditional seed used in hemp cultivation in the Bama County. The seeds contain abundant unsaturated fatty acids, particularly linoleic acid (LA) and linolenic acid in the golden ratio. These two substances have been proven to be related to human health and the prevention of various diseases. However, the seed development and seed oil accumulation mechanisms remain unclear. This study employed a combined analysis of physiological, transcriptomic, and metabolomic parameters to elucidate the fatty acid formation patterns in Bama hemp seeds throughout development. We found that seed oil accumulated at a late stage in embryo development, with seed oil accumulation following an "S″-shaped growth curve, and positively correlated with seed size, sugar content, protein content, and starch content. Transcriptome analysis identified genes related to the metabolism of LA, α-linolenic acid (ALA), and jasmonic acid (JA). We found that the FAD2 gene was upregulated 165.26 folds and the FAD3 gene was downregulated 6.15 folds at day 21. Metabolomic changes in LA, ALA, and JA compounds suggested a competitive relationship among these substances. Our findings indicate that the peak period of substance accumulation and nutrient accumulation in Bama hemp seeds occurs during the midstage of seed development (day 21) rather than in the late stage (day 40). The results of this research will provide a theoretical basis for local cultivation and deep processing of Bama hemp.

Shoots and Turions of Aquatic Plants as a Source of Fatty Acids.

BACKGROUND: Fatty acids are essential for human health. Currently, there is a search for alternative sources of fatty acids that could supplement such sources as staple crops or fishes. Turions of aquatic plants accumulate a variety of substances such as starch, free sugars, amino acids, reserve proteins and lipids. Our aim is to see if turions can be a valuable source of fatty acids. METHODS: Overwintering shoots and turions of aquatic carnivorous plants were collected. The plant material was extracted with hexane. The oils were analyzed using a gas chromatograph with mass spectrometer. RESULTS: The dominant compound in all samples was linolenic acid. The oil content was different in turions and shoots. The oil content of the shoots was higher than that of the turions, but the proportion of fatty acids in the oils from the shoots was low in contrast to the oils from the turions. The turions of Utricularia species were shown to be composed of about 50% fatty acids. CONCLUSIONS: The turions of Utricularia species can be used to obtain oil with unsaturated fatty acids. In addition, the high fatty acid content of turions may explain their ability to survive at low temperatures.

Daily Consumption of α-Linolenic Acid Increases Conversion Efficiency to Eicosapentaenoic Acid in Mice.

To maintain a beneficial concentration of eicosapentaenoic acid (EPA), the efficient conversion of its precursor, α-linolenic acid (α-LA), is important. Here, we studied the conversion of α-LA to EPA using ICR and C57BL/6 mice. A single dose of perilla oil rich-in α-LA or free α-LA had not been converted to EPA 18 h following administration. The α-LA was absorbed into the circulation, and its concentration peaked 6 h after administration, after which it rapidly decreased. In contrast, EPA administration was followed by an increase in circulating EPA concentration, but this did not decrease between 6 and 18 h, indicating that the clearance of EPA is slower than that of α-LA. After ≥1 week perilla oil intake, the circulating EPA concentration was >20 times higher than that of the control group which consumed olive oil, indicating that daily consumption, but not a single dose, of α-LA-rich oil might help preserve the physiologic EPA concentration. The consumption of high concentrations of perilla oil for 4 weeks also increased the hepatic expression of Elovl5, which is involved in fatty acid elongation; however, further studies are needed to characterize the relationship between the expression of this gene and the conversion of α-LA to EPA.

Physical and oxidative stability of flaxseed oil-in-water emulsions prepared by natural lignin-carbohydrate complex.

Flaxseed oil, rich in α-linolenic acid, plays a crucial role in various physiological processes. However, its stability presents certain challenges. In this study, the natural lignin-carbohydrate complex (LCC) was used to prepare the physical and oxidative stability of flaxseed oil-in-water emulsions. The LCC was characterized by HPLC, GPC, and FT-IR. The stability of emulsions was evaluated by viscosity, modulus, and micro-morphology changes. Then, the oxidation products were monitored by UV-vis spectrophotometer and HPLC. The results revealed that the high internal phase emulsion (HIPE) was successfully prepared with 2.5 wt% LCC at an oil/water ratio of 75/25 (v/v). Small droplet size (13.361 µm) and high viscosity (36,500 mPa·s) were found even after 30-day storage. Steric interactions of the LCC play a crucial role in ensuring stability, intricately linked to the interfacial properties of the emulsion. Meanwhile, the oxidative stability of α-linolenic acid in the encapsulated flaxseed oil was significantly higher than that in the bulk flaxseed oil. The results revealed that the LCC as a suitable emulsifier opens a new window for the storage of functional lipids rich in polyunsaturated fatty acids.

Phytochemical investigation of the n-hexane-extracted oil from four umbelliferous vegetables using GC/MS analysis in the context of antibacterial activity.

Umbelliferous (Apiaceae) vegetables are widely consumed worldwide for their nutritive and health benefits. The main goal of the current study is to explore the compositional heterogeneity in four dried umbelliferous vegetables viz, celery, coriander, dill, and parsley targeting their volatile profile using gas chromatography-mass spectrometry (GC-MS). A total of 133 volatile metabolites were detected belonging to 12 classes. Aromatic hydrocarbons were detected as the major components of the analyzed vegetables accounting ca. 64.0, 62.4, 59.5, and 47.8% in parsley, dill, celery, and coriander, respectively. Aliphatic hydrocarbons were detected at ca. 6.39, 8.21, 6.16, and 6.79% in parsley, dill, celery, and coriander, respectively. Polyunsaturated fatty acids (PUFA) of various health benefits were detected in parsley and represented by roughanic acid and α-linolenic acid at 4.99 and 0.47%, respectively. Myristicin and frambinone were detected only in parsley at 0.45 and 0.56%. Investigation of antibacterial activity of umbelliferous vegetables n-hexane extract revealed a moderate antibacterial activity against Gram-positive and Gram-negative bacteria with higher activity for celery and dill against Staphylococcus aureus with inhibition zone 20.3 mm compared to 24.3 mm of the standard antibacterial drug.

The balance of n-6 and n-3 fatty acids in canine, feline, and equine nutrition: exploring sources and the significance of alpha-linolenic acid.

Both n-6 and n-3 fatty acids (FA) have numerous significant physiological roles for mammals. The interplay between these families of FA is of interest in companion animal nutrition due to the influence of the n-6:n-3 FA ratio on the modulation of the inflammatory response in disease management and treatment. As both human and animal diets have shifted to greater consumption of vegetable oils rich in n-6 FA, the supplementation of n-3 FA to canine, feline, and equine diets has been advocated for. Although fish oils are commonly added to supply the long-chain n-3 FA eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), a heavy reliance on this ingredient by the human, pet food, and equine supplement industries is not environmentally sustainable. Instead, sustainable sourcing of plant-based oils rich in n-3 α-linolenic acid (ALA), such as flaxseed and camelina oils, emerges as a viable option to support an optimal n-6:n-3 FA ratio. Moreover, ALA may offer health benefits that extend beyond its role as a precursor for endogenous EPA and DHA production. The following review underlines the metabolism and recommendations of n-6 and n-3 FA for dogs, cats, and horses and the ratio between them in promoting optimal health and inflammation management. Additionally, insights into both marine and plant-based n-3 FA sources will be discussed, along with the commercial practicality of using plant oils rich in ALA for the provision of n-3 FA to companion animals.

In the realm of companion animal nutrition, the balance between the n-6 and n-3 fatty acids (FA) is important. The shared metabolic pathway of these two FA families and the respective signaling molecules produced have implications for the well-being of companion animals such as dogs, cats, and even horses. The n-6:n-3 FA ratio of the diet can directly influence inflammatory responses, disease management, and overall health. Given the prevalent use of n-6 FA-rich vegetable oils in both human and animal diets, there is a growing need to supplement these animals' diets with n-3 FA. While fish oils containing the long-chain n-3 FA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been the conventional choice, their overreliance is environmentally unsustainable. Plant-based oils abundant in the n-3 FA α-linolenic acid (ALA) such as flaxseed and camelina oils should be considered, especially given the health benefits of ALA that extend beyond its role as a precursor to EPA and DHA. This review examines the importance of n-3 FA and the n-6:n-3 FA ratio in companion animal diets on animal health while discussing environmentally sustainable alternatives to fish oil to supplement n-3 FA.

Current Insights into the Effects of Dietary α-Linolenic Acid Focusing on Alterations of Polyunsaturated Fatty Acid Profiles in Metabolic Syndrome.

The plant-derived α-linolenic acid (ALA) is an essential n-3 acid highly susceptible to oxidation, present in oils of flaxseeds, walnuts, canola, perilla, soy, and chia. After ingestion, it can be incorporated in to body lipid pools (particularly triglycerides and phospholipid membranes), and then endogenously metabolized through desaturation, elongation, and peroxisome oxidation to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with a very limited efficiency (particularly for DHA), beta-oxidized as an energy source, or directly metabolized to C18-oxilipins. At this moment, data in the literature about the effects of ALA supplementation on metabolic syndrome (MetS) in humans are inconsistent, indicating no effects or some positive effects on all MetS components (abdominal obesity, dyslipidemia, impaired insulin sensitivity and glucoregulation, blood pressure, and liver steatosis). The major effects of ALA on MetS seem to be through its conversion to more potent EPA and DHA, the impact on the n-3/n-6 ratio, and the consecutive effects on the formation of oxylipins and endocannabinoids, inflammation, insulin sensitivity, and insulin secretion, as well as adipocyte and hepatocytes function. It is important to distinguish the direct effects of ALA from the effects of EPA and DHA metabolites. This review summarizes the most recent findings on this topic and discusses the possible mechanisms.

Differential Modulation by Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) of Mesenteric Fat and Macrophages and T Cells in Adipose Tissue of Obese fa/fa Zucker Rats.

Polyunsaturated fatty acids (PUFAs) can alter adipose tissue function; however, the relative effects of plant and marine n3-PUFAs are less clear. Our objective was to directly compare the n3-PUFAs, plant-based α-linolenic acid (ALA) in flaxseed oil, and marine-based eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in high-purity oils versus n6-PUFA containing linoleic acid (LA) for their effects on the adipose tissue and oral glucose tolerance of obese rats. Male fa/fa Zucker rats were assigned to faALA, faEPA, faDHA, and faLA groups and compared to baseline fa/fa rats (faBASE) and lean Zucker rats (lnLA). After 8 weeks, faEPA and faDHA had 11-14% lower body weight than faLA. The oral glucose tolerance and total body fat were unchanged, but faEPA had less mesenteric fat. faEPA and faDHA had fewer large adipocytes compared to faLA and faALA. EPA reduced macrophages in the adipose tissue of fa/fa rats compared to ALA and DHA, while faLA had the greatest macrophage infiltration. DHA decreased (~10-fold) T-cell infiltration compared to faBASE and faEPA, whereas faALA and faLA had an ~40% increase. The n3-PUFA diets attenuated tumour necrosis factor-α in adipose tissue compared to faBASE, while it was increased by LA in both genotypes. In conclusion, EPA and DHA target different aspects of inflammation in adipose tissue.

Arabidopsis seeds altered in the circadian clock protein TOC1 are characterized by higher level of linolenic acid.

The circadian clock plays a critical role in regulating plant physiology and metabolism. However, the way in which the clock impacts the regulation of lipid biosynthesis in seeds is partially understood. In the present study, we characterized the seed fatty acid (FA) and glycerolipid (GL) compositions of pseudo-response regulator mutants. Among these mutants, toc1 (timing of cab expression 1) exhibited the most significant differences compared to control plants. These included an increase in total FA content, characterized by elevated levels of linolenic acid (18:3) along with a reduction in linoleic acid (18:2). Furthermore, our findings revealed that toc1 developing seeds showed increased expression of genes related to FA metabolism. Our results show a connection between TOC1 and lipid metabolism in Arabidopsis seeds.

Structural identification and antioxidant activity of trans-9, trans-11, cis-15-conjugated linolenic acid converted by probiotics.

The study aimed to determine the chemical structures of octadecatrienoic acid isomers produced by probiotics through the bioconversion of α-linolenic acid and to assess their antioxidant capacities. The chemical structures were identified using nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS), while the antioxidant capacities were evaluated in vitro and in cellular. The NMR signals obtained allowed for definitive characterization, with the main ion fragments detected being m/z 58.0062, 59.0140, 71.0141, 113.0616, 127.0777, and 181.5833. Compounds at concentrations below 40 µM maintained the antioxidant capacity of HepG2 cells by protecting endogenous antioxidative enzymes and mitochondrial membrane potential. However, doses higher than 40 µM increase oxidative damage and mitochondrial dysfunction. These results confirmed the structure of the probiotic-derived compound as trans9, trans11, cis15-conjugated linolenic acid. Additionally, appropriate doses of CLNA can alleviate oxidative stress induced by AAPH, while high doses aggravate cellular damage. These findings provide foundational information for the further exploration of probiotic-derived edible lipids.

[Quality control of Tianwang Buxin Pills based on UPLC fingerprint and multi-component quantification].

Tianwang Buxin Pills have demonstrated therapeutic effects in clinical practice, whereas there is a serious lack of comprehensive quality control to ensure the safety and effectiveness of clinical medication. In this study, ultra-performance liquid chromatography(UPLC) was employed to establish the fingerprint and the method for simultaneously determining the content of seven components of Tianwang Buxin Pills. Furthermore, chemometrics was employed to identify the key factors for the stable quality, which provided a reference for the comprehensive quality control and evaluation of this preparation. There were 25 common peaks in the UPLC fingerprints of 15 batches of Tianwang Buxin Pills, from which thirteen compounds were identified. A quantitation method was established for seven pharmacological components(α-linolenic acid, salvianolic acid B, glycyrrhetinic acid, schisandrin A, ß-asarone, 3,6'-disinapoylsucrose, and ligustilide). The principal component analysis(PCA) and partial least square discriminate analysis(PLS-DA) were performed to determine the key pharmacological components for controlling the quality stability of Tianwang Buxin Pills, which included 3,6'-disinapoylsucrose, α-linolenic acid, and ß-asarone. The established fingerprint and multi-component content determination method have strong specificity, stability, and reliability. In addition, 3,6'-disinapoylsucrose, α-linolenic acid, and ß-asarone are the key pharmacological components that ensure the quality stability between batches and can be used to comprehensively control the quality of Tianwang Buxin Pills. The findings provide a scientific basis for the quality evaluation and standard establishment of Tianwang Buxin Pills.

Integrated multi-omics analysis reveals liver metabolic reprogramming by fish iridovirus and antiviral function of alpha-linolenic acid.

Iridovirus poses a substantial threat to global aquaculture due to its high mortality rate; however, the molecular mechanisms underpinning its pathogenesis are not well elucidated. Here, a multi-omics approach was applied to groupers infected with Singapore grouper iridovirus (SGIV), focusing on the roles of key metabolites. Results showed that SGIV induced obvious histopathological damage and changes in metabolic enzymes within the liver. Furthermore, SGIV significantly reduced the contents of lipid droplets, triglycerides, cholesterol, and lipoproteins. Metabolomic analysis indicated that the altered metabolites were enriched in 19 pathways, with a notable down-regulation of lipid metabolites such as glycerophosphates and alpha-linolenic acid (ALA), consistent with disturbed lipid homeostasis in the liver. Integration of transcriptomic and metabolomic data revealed that the top enriched pathways were related to cell growth and death and nucleotide, carbohydrate, amino acid, and lipid metabolism, supporting the conclusion that SGIV infection induced liver metabolic reprogramming. Further integrative transcriptomic and proteomic analysis indicated that SGIV infection activated crucial molecular events in a phagosome-immune depression-metabolism dysregulation-necrosis signaling cascade. Of note, integrative multi-omics analysis demonstrated the consumption of ALA and linoleic acid (LA) metabolites, and the accumulation of L-glutamic acid (GA), accompanied by alterations in immune, inflammation, and cell death-related genes. Further experimental data showed that ALA, but not GA, suppressed SGIV replication by activating antioxidant and anti-inflammatory responses in the host. Collectively, these findings provide a comprehensive resource for understanding host response dynamics during fish iridovirus infection and highlight the antiviral potential of ALA in the prevention and treatment of iridoviral diseases.

The potential of Paeonia lactiflora pall seeds oil as a pure natural cosmetics raw material: In Vitro findings.

BACKGROUND: As a traditional Chinese herbal medicine, Paeonia lactiflora Pall is rich in various active ingredients such as polysaccharides and total flavonoids while having ornamental value. It has potential application value in the development of food and cosmetics. OBJECTIVE: To study the in vitro efficacy of Paeonia lactiflora Pall seeds oil. METHODS: Firstly, the levels of linolenic acid and linoleic acid in Paeonia lactiflora Pall seeds oil were quantified using gas chromatography. The impact of Paeonia lactiflora Pall seeds oil on the proliferation rate of B16F10 cells was assessed through the CCK-8 method, while the melanin content of B16F10 cells was determined using the sodium hydroxide lysis method. The inhibitory effects of Paeonia lactiflora Pall seeds oil on elastase, collagenase and hyaluronidase were evaluated by biochemical techniques in vitro. Lastly, the hen's egg chorioallantoic membrane test (HET-CAM) was conducted to confirm the absence of eye irritation caused by Paeonia lactiflora Pall seeds oil. RESULTS: Paeonia lactiflora Pall seeds oil within a certain volume concentration range (0.5%-4%) had no effect on the proliferation of B16F10 cells. Paeonia lactiflora Pall seeds oil showed significant inhibition of elastase, collagenase and hyaluronidase. Notably, the highest concentration tested, 4% Paeonia lactiflora Pall seed oil, yielded the most pronounced outcomes without causing any irritation. CONCLUSION: A certain concentration of Paeonia lactiflora Pall seeds oil has a significant effect on decreasing the melanin content in B16F10 cells and inhibiting the activities of elastase, collagenase, and hyaluronidase, which can provide a reference for the development of pure natural cosmetics raw materials.

Impact of changes in root biomass on the occurrence of internal browning in radish root.

The purpose of this study was to investigate the effects of root biomass during the later stage of growth on fatty acid composition and lipid peroxidation, and to clarify the physiological mechanisms by which these differences affect internal browning (IB) development in radish roots. Therefore, we controlled the enlargement of roots by changing the thinning period and generated plots composed of roots with different biomass in the latter half of growth. The earlier the radish seedlings were thinned, the more vigorous the root growth from an earlier stage was achieved. Earlier thinning caused IB from the early stage of root maturation, and IB severity progressed with subsequent age progression; however, IB damage did not occur when root size during the later growth stage was kept small by later thinning. Higher levels of hydrogen peroxide, peroxidase activity, NADPH-dependent reactive oxygen species (ROS) burst-related genes, and carbonyl compounds were detected in earlier-thinned large-sized roots compared to later-thinned small-sized ones. Compared with the latter small-sized roots, the former large-sized roots had a lower ratio of linoleic acid (18:2) and a higher ratio of α-linolenic acid (α-18:3). Furthermore, in earlier-thinned large-sized roots, higher levels of phospholipase- and/or lipoxygenase-related genes were detected compared to later-thinned small-sized ones. These facts suggest the possibility that root biomass in the later stage of growth affects the desaturation of membrane fatty acids, ROS concentration, and activity of fatty acid degrading enzymes, and controls the occurrence of IB injury through membrane oxidative degradation.

Conjugated Linolenic Acid (CLnA) vs Conjugated Linoleic Acid (CLA): A Comprehensive Review of Potential Advantages in Molecular Characteristics, Health Benefits, and Production Techniques.

Conjugated linoleic acid (CLA) has been extensively characterized due to its many biological activities and health benefits, but conjugated linolenic acid (CLnA) is still not well understood. However, CLnA has shown to be more effective than CLA as a potential functional food ingredient. Current research has not thoroughly investigated the differences and advantages between CLnA and CLA. This article compares CLnA and CLA based on molecular characteristics, including structural, chemical, and metabolic characteristics. Then, the in vivo research evidence of CLnA on various health benefits is comprehensively reviewed and compared with CLA in terms of effectiveness and mechanism. Furthermore, the potential of CLnA in production technology and product protection is analyzed. In general, CLnA and CLA have similar physicochemical properties of conjugated molecules and share many similarities in regulation effects and pathways of various health benefits as well as in the production methods. However, their specific properties, regulatory capabilities, and unique mechanisms are different. The superior potential of CLnA must be specified according to the practical application patterns of isomers. Future research should focus more on the advantageous characteristics of different isomers, especially the effectiveness and safety in clinical applications in order to truly exert the potential value of CLnA.

Biochemical and Biophysical Characterization of Tau and α-Linolenic Acid Vesicles In Vitro.

Alzheimer's disease (AD) is characterized by the abnormal accumulation of disordered protein, that is, extracellular senile plaques of amyloid-ß (Aß) and intracellular neurofibrillary tangles of Tau. Tau protein has gained the attention in recent years owing to the ability to propagate in a "prion-like" nature. The disordered protein Tau possesses a high positive charge, which allows its binding to anionic proteins and factors. The native disorder of proteins attends the ß-sheet structure from its random-coiled conformation upon charge compensation by various polyanionic agents such as heparin, RNA, etc. Anionic lipids such as arachidonic acid (AA) and oleic acid (OA) are also one of the factors which can induce aggregation of Tau in physiological conditions. The free units of Tau protein can bind to lipid membranes through its repeat domain (RD), the anionic side chains of the membrane lipids induce aggregation of Tau by reducing the activation barrier. In this study, we investigated the role of α-linolenic acid (ALA) as an inducing agent for Tau aggregation in vitro conditions. Omega-3 fatty acids bear a capacity to reduce the pathology of Tau by downregulating the Tau phosphorylation pathway. We have studied by using various biochemical or biophysical methods the potency of ALA as an aggregating agent for Tau. We have implemented different techniques such as SDS-PAGE, transmission electron microscopy, CD spectroscopy to evaluated higher-order aggregates of Tau upon induction by ALA.

α-Linolenic Acid Induces Microglial Activation and Extracellular Tau Internalization.

Neuroinflammation is the brain condition that occurs due to the hyper-activation of brain's immune cells and microglia, over the stimulation of extracellular aggregated proteins such as amyloid plaques and by extracellular Tau as well. The phenotypic changes of microglia from inflammatory to anti-inflammatory can be triggered by many factors, which also includes dietary fatty acids. The classes of omega-3 fatty acids are the majorly responsible in maintaining the anti-inflammatory phenotype of microglia. The enhanced phagocytic ability of microglia might induce the clearance of extracellular aggregated proteins, such as amyloid beta and Tau. In this study, we emphasized on the effect of α-linolenic acid (ALA) on the activation of microglia and internalization of the extracellular Tau seed in microglia.