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.

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.

Internalization and Endosomal Trafficking of Extracellular Tau in Microglia Improved by α-Linolenic Acid.

Alzheimer's disease (AD) is distinguished by extracellular accumulation of amyloid-beta plaques and intracellular neurofibrillary tangles of Tau. Pathogenic Tau species are also known to display "prion-like propagation," which explains their presence in extracellular spaces as well. Glial population, especially microglia, tend to proclaim neuroinflammatory condition, disrupted signaling mechanisms, and cytoskeleton deregulation in AD. Omega-3 fatty acids play a neuroprotective role in the brain, which can trigger the anti-inflammatory pathways as well as actin dynamics in the cells. Improvement of cytoskeletal assembly mechanism by omega-3 fatty acids would regulate the other signaling cascades in the cells, leading to refining clearance of extracellular protein burden in AD. In this study, we focused on analyzing the ability of α-linolenic acid (ALA) as a regulator of actin dynamics to balance the signaling pathways in microglia, including endocytosis of extracellular Tau burden in AD.

Exogenous alpha-linolenic acid and Vibrio parahaemolyticus induce EPA and DHA levels mediated by delta-6 desaturase to enhance shrimp immunity.

Globally, penaeid shrimp are the most farmed and traded aquatic organisms, although they are easily susceptible to microbial pathogens. Moreover, there is a desire to increase the nutritional value of shrimp, especially the levels of n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which also possess immunomodulatory and anti-inflammatory properties. Some aquatic animals can synthesize EPA and DHA from dietary plant-sourced alpha-linolenic acid (ALA), but penaeid shrimps' ability to synthesize these n-3 PUFAs is unknown. Here, molecular biology techniques, including gas chromatography-mass spectrometry, qPCR, ELISA, etc., were used to demonstrate that exogenous ALA or Vibrio parahaemolyticus could modulate EPA and DHA levels and immune genes in Penaeus vannamei by inducing key enzymes involved in n-3 PUFAs biosynthesis, such as delta desaturases and elongation of very long-chain fatty acid (ELOVLs). Most importantly, knockdown or inhibition of ∆6 desaturase significantly decreased EPA and DHA levels and immune gene expression even with exogenous ALA treatment, consequently affecting shrimp antibacterial immunity and survival. This study provides new insight into the potential of P. vannamei to synthesize n-3 PUFAs from exogenous ALA or upon bacteria challenge, which could be leveraged to increase their nutritional content and antimicrobial immunity.

Important roles of linoleic acid and α-linolenic acid in regulating cognitive impairment and neuropsychiatric issues in metabolic-related dementia.

Metabolic syndrome (MetS), which is characterized by insulin resistance, high blood glucose, obesity, and dyslipidemia, is known to increase the risk of dementia accompanied by memory loss and depression. The direct pathways and specific mechanisms in the central nervous system (CNS) for addressing fatty acid imbalances in MetS have not yet been fully elucidated. Among polyunsaturated acids, linoleic acid (LA, n6-PUFA) and α-linolenic acid (ALA, n3-PUFA), which are two essential fatty acids that should be provided by food sources (e.g., vegetable oils and seeds), have been reported to regulate various cellular mechanisms including apoptosis, inflammatory responses, mitochondrial biogenesis, and insulin signaling. Furthermore, inadequate intake of LA and ALA is reported to be involved in neuropathology and neuropsychiatric diseases as well as imbalanced metabolic conditions. Herein, we review the roles of LA and ALA on metabolic-related dementia focusing on insulin resistance, dyslipidemia, synaptic plasticity, cognitive function, and neuropsychiatric issues. This review suggests that LA and ALA are important fatty acids for concurrent treatment of both MetS and neurological problems.

Alpha-linolenic acid protects against methotrexate-induced nephrotoxicity in mouse kidney cells.

OBJECTIVE: Methotrexate (MTX) is a folic acid antagonist used in chronic inflammatory diseases and various cancer treatments. Although the main mechanism of the toxic effect of MTX is not known, it is stated that it causes oxidative stress and inflammation. Alpha-linolenic acid (ALA) protects against oxidative stress, apoptosis, and inflammation. For this reason, we aimed to find out the useful effect of ALA on MTX-induced nephrotoxicity MATERIALS AND METHODS: The mice were divided into 4 groups randomly. The control group was treated with physiological saline solution; the ALA group was treated with ALA (200 mg/kg) by gavage; MTX-treated group received 20 mg/kg i.p. (intraperitoneal) MTX; and MTX+ALA treated group received 20 mg/kg i.p. MTX and ALA 200 mg/kg by gavage. All of the drugs were performed once a day for 9 days. RESULTS: Alpha-linolenic acid significantly decreased oxidative stress parameters and MTX-induced inflammatory and apoptotic mediators. Furthermore, histopathological examination showed that MTX induced significant edematous damage, and ALA treatment attenuated this damage in renal tissue. CONCLUSIONS: Our results revealed that ALA may be helpful against MTX-induced nephrotoxicity in mice via its antioxidant and anti-inflammatory properties.

Protective Effect of Alpha-Linolenic Acid on Human Oral Squamous Cell Carcinoma Metastasis and Apoptotic Cell Death.

Oral cancer ranks sixth among Taiwan's top 10 cancers and most patients with poor prognosis acquire metastases. The essential fatty acid alpha-linolenic acid (ALA) has been found to diminish many cancer properties. However, the anti-cancer activity of ALA in oral cancer has yet to be determined. We examined the mechanisms underlying ALA inhibition of metastasis and induction of apoptotic cell death in oral squamous cell carcinoma (OSCC). Migration and invasion assays confirmed the cancer cells' EMT capabilities, whereas flow cytometry and Western blotting identified molecular pathways in OSCC. ALA dramatically reduced cell growth in a concentration-dependent manner according to the findings. Low concentrations of ALA (100 or 200 µM) inhibit colony formation, the expression of Twist and EMT-related proteins, the expression of MMP2/-9 proteins, and enzyme activity, as well as cell migration and invasion. Treatment with high concentrations of ALA (200 or 400 µM) greatly increases JNK phosphorylation and c-jun nuclear accumulation and then upregulates the FasL/caspase8/caspase3 and Bid/cytochrome c/caspase9/caspase3 pathways, leading to cell death. Low concentrations of ALA inhibit SAS and GNM cell migration and invasion by suppressing Twist and downregulating EMT-related proteins or by decreasing the protein expression and enzyme activity of MMP-2/-9, whereas high concentrations of ALA promote apoptosis by activating the JNK/FasL/caspase 8/caspase 3-extrinsic pathway and the Bid/cytochrome c/caspase 9 pathway. ALA demonstrates potential as a treatment for OSCC patients.

Effect of Alpha-Linolenic Acid Supplementation on Cardiovascular Disease Risk Profile in Individuals with Obesity or Overweight: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Overweight and obesity are highly prevalent worldwide and are associated with cardiovascular disease (CVD) risk factors, including systematic inflammation, dyslipidemia, and hypertension. Alpha-linolenic acid (ALA) is a plant-based essential polyunsaturated fatty acid associated with reduced CVD risks. This systematic review and meta-analysis aimed to investigate the effects of supplementation with ALA compared with the placebo on CVD risk factors in people with obesity or overweight (International Prospective Register of Systematic Reviews Registration No. CRD42023429563). This review included studies with adults using oral supplementation or food or combined interventions containing vegetable sources of ALA. All studies were randomly assigned trials with parallel or crossover designs. The Cochrane Collaboration tool was used for assessing the risk of bias (Version 1). PubMed, Web of Science, Embase, and Cochrane library databases were searched from inception to April 2023. Nineteen eligible randomized controlled trials, including 1183 participants, were included in the meta-analysis. Compared with placebo, dietary ALA supplementation significantly reduced C-reactive protein concentration (standardized mean difference [SMD] = -0.38 mg/L; 95% confidence interval [CI]: -0.72, -0.04), tumor necrosis factor-α concentration (SMD = -0.45 pg/mL; 95% CI: -0.73, -0.17), triglyceride in serum (SMD = -4.41 mg/dL; 95% CI: -5.99, -2.82), and systolic blood pressure (SMD = -0.37 mm Hg; 95% CI: -0.66, -0.08); but led to a significant increase in low-density lipoprotein cholesterol concentrations (SMD = 1.32 mg/dL; 95% CI: 0.05, 2.59). ALA supplementation had no significant effect on interleukin-6, diastolic blood pressure, total cholesterol, or high-density lipoprotein cholesterol (all P ≥ 0.05). Subgroup analysis revealed that ALA supplementation at a dose of ≥3 g/d from flaxseed and flaxseed oil had a more prominent effect on improving CVD risk profiles, particularly where the intervention duration was ≥12 wk and where the baseline CVD profile was poor.

Linolenic acid-metronidazole inhibits the growth of Helicobacter pylori through oxidation.

BACKGROUND: Resistance to antibiotics is one the main factors constraining the treatment and control of Helicobacter pylori (H. pylori) infections. Therefore, there is an urgent need to develop new antimicrobial agents to replace antibiotics. Our previous study found that linolenic acid-metronidazole (Lla-Met) has a good antibacterial effect against H. pylori, both antibiotic-resistant and sensitive H. pylori. Also, H. pylori does not develop resistance to Lla-Met. Therefore, it could be used for preparing broad-spectrum antibacterial agents. However, since the antibacterial mechanism of Lla-Met is not well understood, we explored this phenomenon in the present study. AIM: To understand the antimicrobial effect of Lla-Met and how this could be applied in treating corresponding infections. METHODS: H. pylori cells were treated with the Lla-Met compound, and the effect of the compound on the cell morphology, cell membrane permeability, and oxidation of the bacteria cell was assessed. Meanwhile, the differently expressed genes in H. pylori in response to Lla-Met treatment were identified. RESULTS: Lla-Met treatment induced several changes in H. pylori cells, including roughening and swelling. In vivo experiments revealed that Lla-Met induced oxidation, DNA fragmentation, and phosphatidylserine ectropionation in H. pylori cells. Inhibiting Lla-Met with L-cysteine abrogated the above phenomena. Transcriptome analysis revealed that Lla-Met treatment up-regulated the expression of superoxide dismutase SodB and MdaB genes, both anti-oxidation-related genes. CONCLUSION: Lla-Met kills H. pylori mainly by inducing oxidative stress, DNA damage, phosphatidylserine ectropionation, and changes on cell morphology.

Alpha-Linolenic Acid and Cardiovascular Events: A Narrative Review.

Cardiovascular diseases (CVDs) represent the leading cause of global mortality with 1.7 million deaths a year. One of the alternative systems to drug therapy to minimize the risk of CVDs is represented by alpha-linolenic acid (ALA), an essential fatty acid of the omega-3 series, known for its cholesterol-lowering effect. The main purpose of this review is to analyze the effects of ALA and investigate the relevant omega-6/omega-3 ratio in order to maintain functionally beneficial effects. Concerning the lipid-lowering preventive effects, ALA may favorably affect the values of LDL-C and triglycerides in both adult and pediatric populations. Furthermore, ALA has shown protective effects against hypertension, contributing to balancing blood pressure through customary diet. According to the 2009 EFSA statement, dietary ALA may contribute to reducing the risk of CVDs, thanks to anti-hypertensive, anti-atherosclerotic and cardioprotective effects.

The Effects of a Low Linoleic Acid/α-Linolenic Acid Ratio on Lipid Metabolism and Endogenous Fatty Acid Distribution in Obese Mice.

A reduced risk of obesity and metabolic syndrome has been observed in individuals with a low intake ratio of linoleic acid/α-linolenic acid (LA/ALA). However, the influence of a low ratio of LA/ALA intake on lipid metabolism and endogenous fatty acid distribution in obese patients remains elusive. In this investigation, 8-week-old C57BL/6J mice were randomly assigned to four groups: low-fat diet (LFD) as a control, high-fat diet (HFD), high-fat diet with a low LA/ALA ratio (HFD+H3L6), and high-fat diet with a high LA/ALA ratio (HFD+L3H6) for 16 weeks. Our results show that the HFD+H3L6 diet significantly decreased the liver index of HFD mice by 3.51%, as well as the levels of triacylglycerols (TGs) and low-density lipoprotein cholesterol (LDL-C) by 15.67% and 10.02%, respectively. Moreover, the HFD+H3L6 diet reduced the pro-inflammatory cytokines interleukin-6 (IL-6) level and aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio and elevated the level of superoxide dismutase (SOD) in the liver. The HFD+H3L6 diet also resulted in the downregulation of fatty acid synthetase (FAS) and sterol regulatory element binding proteins-1c (SREBP-1c) expression and the upregulation of peroxisome proliferator-activated receptor-α (PPAR-α) and acyl-CoA oxidase 1 (ACOX1) gene expression in the liver. The low LA/ALA ratio diet led to a notable increase in the levels of ALA and its downstream derivative docosahexaenoic acid (DHA) in the erythrocyte, liver, perienteric fat, epididymal fat, perirenal fat, spleen, brain, heart, and gastrocnemius, with a strong positive correlation. Conversely, the accumulation of LA in abdominal fat was more prominent, and a high LA/ALA ratio diet exacerbated the deposition effect of LA. In conclusion, the low LA/ALA ratio not only regulated endogenous fatty acid levels but also upregulated PPAR-α and ACOX1 and downregulated SREBP-1c and FAS gene expression levels, thus maintaining lipid homeostasis. Optimizing dietary fat intake is important in studying lipid nutrition. These research findings emphasize the significance of understanding and optimizing dietary fat intake.

α-Linolenic acid-regulated testosterone biosynthesis via activation of the JNK-SF-1 signaling pathway in primary rooster Leydig cells.

As a functional fatty acid, α-linolenic acid (ALA) is essential in promoting animal testosterone biosynthesis. This study investigated the effects of ALA on testosterone biosynthesis and the possible mechanism underlying the signaling pathway in primary Leydig cells of the rooster. METHODS: Primary rooster Leydig cells were treated with ALA (0, 20, 40, or 80 µmol/L) or pretreated with a p38 inhibitor (50 µmol/L), a c-Jun NH2-terminal kinase (JNK) inhibitor (20 µmol/L), or an extracellular signal-regulated kinase (ERK) inhibitor (20 µmol/L) before ALA treatment. Testosterone content in the conditioned culture medium was detected using an enzyme-linked immunosorbent assay (ELISA). The expression of steroidogenic enzymes and JNK-SF-1 signaling pathway factors was detected using real-time fluorescence quantitative PCR (qRT-PCR). RESULTS: Supplementation with ALA significantly increased testosterone secretion within culture media (P < 0.05), and the optimized dose was 40 µmol/L. Compared with the control group, steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) mRNA expression significantly increased (P < 0.05) in the 40 µmol/L ALA group; 17-hydroxylase/c17-20 lyase (P450c17) and p38 mRNA expressions were not significantly different in the 40 µmol/L ALA group; ERK and JNK mRNA expressions were significantly upregulated (P < 0.05) in 40 µmol/L ALA group. In the inhibitor group, testosterone levels were significantly downregulated (P < 0.05). Compared with the 40 µmol/L ALA group, StAR, P450scc, and P450c17 mRNA expressions were significantly decreased (P < 0.05), and 3ß-HSD mRNA expression in the p38 inhibitor group did not change; StAR, P450scc, and 3ß-HSD mRNA expressions were significantly decreased (P < 0.05), and P450c17 mRNA expression in ERK inhibitor group did not change; StAR, P450scc, 3ß-HSD, and P450c17 mRNA expressions were significantly decreased (P < 0.05) in JNK inhibitor group. Additionally, the increased steroidogenic factor 1 (SF-1) gene expression levels induced by ALA were reversed when the cells were pre-incubated with JNK and ERK inhibitors. The levels in the JNK inhibitor group were significantly lower than those in the control group (P < 0.05). CONCLUSION: ALA may promote testosterone biosynthesis by activating the JNK-SF-1 signaling pathway to upregulate StAR, P450scc, 3ß-HSD, and P450c17 expression in primary rooster Leydig cells.

Identification of alpha-linolenic acid as a broad-spectrum antiviral against zika, dengue, herpes simplex, influenza virus and SARS-CoV-2 infection.

Zika virus (ZIKV) has garnered global attention due to its association with severe congenital defects including microcephaly. However, there are no licensed vaccines or drugs against ZIKV infection. Pregnant women have the greatest need for treatment, making drug safety crucial. Alpha-linolenic acid (ALA), a polyunsaturated ω-3 fatty acid, has been used as a health-care product and dietary supplement due to its potential medicinal properties. Here, we demonstrated that ALA inhibits ZIKV infection in cells without loss of cell viability. Time-of-addition assay revealed that ALA interrupts the binding, adsorption, and entry stages of ZIKV replication cycle. The mechanism is probably that ALA disrupts membrane integrity of the virions to release ZIKV RNA, inhibiting viral infectivity. Further examination revealed that ALA inhibited DENV-2, HSV-1, influenza virus and SARS-CoV-2 infection dose-dependently. ALA is a promising broad-spectrum antiviral agent.

Through regulation of the SIRT1 pathway plant sterol ester of α-linolenic acid inhibits pyroptosis thereby attenuating the development of NASH in mice.

Increasing evidence demonstrated that pyroptosis and subsequent inflammation played an important role in the pathological process of non-alcoholic steatohepatitis (NASH). Plant sterol ester of α-linolenic acid (PS-ALA) was beneficial for non-alcoholic fatty liver disease, but the underlying mechanisms are still not fully understood. This study aims to investigate whether PS-ALA can protect against proptosis via regulating SIRT1. Thirty male C57BL/6J mice were fed a normal diet, a high-fat and high-cholesterol diet (HFCD), or a HFCD supplemented with either 1.3%ALA, 2%PS, or 3.3% PS-ALA for 24 weeks. Hepatocytes were treated with oleic acid and cholesterol (OA/Cho) with or without PS-ALA. We found that PS-ALA ameliorated NASH in HFCD-fed mice. In addition, PS-ALA decreased the expression of NLRP3 and ASC and reduced the co-localization of NLRP3 and cleave-Caspase-1. Also, PS-ALA protected against pyroptosis as evidenced by decreased co-localization of GSDMD and propidium iodide (PI) positive cells. Mechanistically, we revealed that the inhibitory action of PS-ALA on the pyroptosis was mediated by SIRT1. This was demonstrated by the fact that silencing SIRT1 with small interfering RNA or inhibition of SIRT1 with its inhibitor abolished the inhibition effect of PS-ALA on the expression of NLRP3 and GSDMD cleavage. Collectively, the data from the present study reveals a novel mechanism that PS-ALA inhibits pyroptosis and it triggered inflammation via stimulating SIRT1, which provides new insights into the beneficial effect of PS-ALA on NASH.

The Effect of Crackers Enriched with Camelina Sativa Oil on Omega-3 Serum Fatty Acid Composition in Older Adults: A Randomized Placebo-Controlled Pilot Trial.

BACKGROUND: Camelina sativa oil is one of the richest dietary sources of omega-3, with polyunsaturated fatty acids amounts of over 50%, linolenic acid content of around 40-45%, and linoleic acid of about 15%. Moreover, this oil is a valuable source of antioxidants which provide oxidative stability. All those features raise interest in considering Camelina oil as an alternative and sustainable oil source providing stable omega-3-rich emulsions for functional food production. OBJECTIVES: The present study aimed to investigate the effects of Camelina oil-enriched crackers on serum omega-3 concentration, inflammatory markers and serum lipid profile. DESIGN: Randomized placebo-controlled pilot trial. SETTING: Research and Development Center (Complife Italia s.r.l.). PARTICIPANTS: Sixty-six free-living older volunteers (aged≥65 years). INTERVENTION: Older adults were enrolled and randomly assigned to one of two groups: the camelina group or the placebo group. Subjects consumed daily 35 g of crackers (Camelina enriched crackers or placebo ones) twice daily for 12 weeks. MEASUREMENTS: Serum polyunsaturated fatty acid profile, inflammatory status and serum lipid panel parameters were recorded pre and post-intervention. RESULTS: In the camelina group, alpha-linolenic acid serum concentration was significantly higher (p<0.01) compared to the placebo group at the end of the study. Concerning inflammatory plasma markers, a significant mean pro-inflammatory interleukin-18 plasma concentration decrease in the placebo group compared to the camelina one was observed (p<0.05). No significant differences in other mean inflammatory markers concentrations post-intervention were noted in either group. Lastly, examining the change in lipid profile, it is noteworthy that a higher reduction of total cholesterol, low-density lipoprotein and triglycerides in the camelina group post-intervention, despite the lack of statistical significance. CONCLUSION: Camelina oil significantly elevated the serum alpha-linolenic acid concentration with no significant changes in inflammatory markers and lipid profile.

Alpha-linolenic acid improves nasal mucosa epithelial barrier function in allergic rhinitis by arresting CD4+ T cell differentiation via IL-4Rα-JAK2-STAT3 pathway.

BACKGROUND: Allergic rhinitis (AR) defined as inflammation and tissue remodeling of the nasal mucosa in atopic individuals after allergen exposure. Alpha-linolenic acid [cis-9, cis-12, cis-15-octadecatrienoic acid (18:3)] (ALA) as dietary supplementation can reduce inflammation and allergic symptoms. OBJECTIVE: To evaluate the potential therapeutic effect and mechanism of ALA in AR mouse model. METHODS: Ovalbumin sensitized AR mouse model were challenged with oral ALA administration. Nasal symptoms, tissue pathology, immune cell infiltration and goblet cell hyperplasia were investigated. Levels of IgE, TNF-ß, IFN-γ, IL-2, IL-4, IL-5, IL-12, IL-13 and IL-25 were determined by ELISA in serum and nasal fluid. Quantitative RT-PCR and immunofluorescence were performed for occludin and zonula occludens-1 expression. CD3+CD4+ T-cells from peripheral blood and splenic lymphocytes were isolated and Th1/Th2 ratio were determined. Mouse naive CD4+ T cell were isolated and Th1/Th2 ratio, IL-4Rα expression, and IL5/IL13 secretion were determined. IL-4Rα-JAK2-STAT3 pathway change in AR mice were performed by western blot. RESULTS: Ovalbumin induced AR, nasal symptoms, pathological performance, IgE, and cytokine production. ALA treated mice showed reduced nasal symptoms, nasal inflammation, nasal septum thickening, goblet cell hyperplasia, and eosinophil infiltration. In serum and nasal fluid of ovalbumin challenged mice, ALA decreased IgE, IL-4 levels, and the increase of Th2-cells. ALA prevented the disruption of the epithelial cell barrier in ovalbumin-challenged AR mice. Simultaneously, ALA prevents IL-4 induced barrier disruption. ALA treatment of AR by affecting the differentiation stage of CD4+T cells and block IL-4Rα-JAK2-STAT3 pathway. CONCLUSION: This study suggests that ALA has the potential therapeutic effect to ovalbumin-induced AR. ALA can affect the differentiation stage of CD4+T cells and improve epithelial barrier functions through IL-4Rα-JAK2-STAT3 pathways. CLINICAL IMPLICATION: ALA might be considered as drug candidate for improving epithelial barrier function through Th1/Th2 ratio recovery in AR.

Alpha-linolenic acid enhances the facilitation of GABAergic neurotransmission in the BLA and CA1.

Hyperexcitability is a major mechanism implicated in several neuropsychiatric disorders, such as organophosphate-induced status epilepticus (SE), primary epilepsy, stroke, spinal cord injury, traumatic brain injury, schizophrenia, and autism spectrum disorders. Underlying mechanisms are diverse, but a functional impairment and loss of GABAergic inhibitory neurons are common features in many of these disorders. While novel therapies abound to correct for the loss of GABAergic inhibitory neurons, it has been difficult at best to improve the activities of daily living for the majority of patients. Alpha-linolenic acid (ALA) is an essential omega-3 polyunsaturated fatty acid found in plants. ALA exerts pleiotropic effects in the brain that attenuate injury in chronic and acute brain disease models. However, the effect of ALA on GABAergic neurotransmission in hyperexcitable brain regions involved in neuropsychiatric disorders, such as the basolateral amygdala (BLA) and CA1 subfield of the hippocampus, is unknown. Administration of a single dose of ALA (1500 nmol/kg) subcutaneously increased the charge transfer of inhibitory postsynaptic potential currents mediated by GABAA receptors in pyramidal neurons by 52% in the BLA and by 92% in the CA1 compared to vehicle animals a day later. Similar results were obtained in pyramidal neurons from the BLA and CA1 when ALA was bath-applied in slices from naïve animals. Importantly, pretreatment with the high-affinity, selective TrkB inhibitor, k252, completely abolished the ALA-induced increase in GABAergic neurotransmission in the BLA and CA1, suggesting a brain-derived neurotrophic factor (BDNF)-mediated mechanism. Addition of mature BDNF (20 ng/mL) significantly increased GABAA receptor inhibitory activity in the BLA and CA1 pyramidal neurons similar to the results obtained with ALA. ALA may be an effective treatment for neuropsychiatric disorders where hyperexcitability is a major feature.

Alpha-linolenic acid modulates systemic and adipose tissue-specific insulin sensitivity, inflammation, and the endocannabinoid system in dairy cows.

Metabolic disorders are often linked to alterations in insulin signaling. Omega-3 (n-3) fatty acids modulate immunometabolic responses; thus, we examined the effects of peripartum n-3 on systemic and adipose tissue (AT)-specific insulin sensitivity, immune function, and the endocannabinoid system (ECS) in dairy cows. Cows were supplemented peripartum with saturated fat (CTL) or flaxseed supplement rich in alpha-linolenic acid (ALA). Blood immunometabolic biomarkers were examined, and at 5-8 d postpartum (PP), an intravenous glucose-tolerance-test (GTT) and AT biopsies were performed. Insulin sensitivity in AT was assessed by phosphoproteomics and proteomics. Peripartum n-3 reduced the plasma concentrations of Interleukin-6 (IL-6) and IL-17α, lowered the percentage of white blood cells PP, and reduced inflammatory proteins in AT. Systemic insulin sensitivity was higher in ALA than in CTL. In AT, the top canonical pathways, according to the differential phosphoproteome in ALA, were protein-kinase-A signaling and insulin-receptor signaling; network analysis and immunoblots validated the lower phosphorylation of protein kinase B (Akt), and lower abundance of insulin receptor, together suggesting reduced insulin sensitivity in ALA AT. The n-3 reduced the plasma concentrations of ECS-associated ligands, and lowered the abundances of cannabinoid-1-receptor and monoglycerol-lipase in peripheral blood mononuclear cells PP. Peripartum ALA supplementation in dairy cows improved systemic insulin sensitivity and immune function, reduced ECS components, and had tissue-specific effects on insulin-sensitivity in AT, possibly counter-balancing the systemic responses.

Cancer cell growth suppressibility of ω-3 fatty acid whose carboxy group converted to ester group.

Recently, ω-3 fatty acids have been revealed to having cancer cell growth suppressibility. It is necessary to analyze the mechanism of cancer cell growth suppressibility and to impart selective cancer cell accumulation when creating anticancer drugs based on ω-3 fatty acids. Therefore, it is necessarily essential to introduce a luminescent molecule or a molecule which have a drug delivery function into ω-3 fatty acids, and the position of introduction is the ω-3 fatty acids' carboxyl group. On the other hand, whether the ω-3 fatty acids' cancer cell growth suppressibility is maintained when the ω-3 fatty acids' carboxyl groups are converted to other structures, such as ester groups, is unclear. In this work, a derivative was synthesized wherein the α-linolenic acid carboxyl group, one of the ω-3 fatty acids, was converted to an ester group and evaluated the cancer cell growth suppressibility, as well as the amount of cancer cell uptake. As a result, it was suggested that the ester group derivatives presented the same functionality as α-linolenic acid, and the ω-3 fatty acid carboxyl group is a flexible functional group, which can be structurally modified in terms of functionality to cancer cells.