Abundant Polyunsaturated Fatty Acids Research Articles

Ameliorative effect of walnut oil against cognitive impairment in alzheimers type dementia in rodent

Walnut oil (WO), known for abundant polyunsaturated fatty acids and an array of bioactive substances such as tocopherols, phytosterols, squalene, melatonin, and polyphenols, which is endowed with numerous health advantages. The primary objective of this research was to ascertain the impact of WO on cognitive deficits in learning and memory impairment mice caused by scopolamine (SCOP). The Morris water maze and the step-down avoidance test were utilized to assess the memory and learning capabilities. WO notably counteracted the detrimental effects of SCOP on learning and memory in the Morris water maze, as indicated by a reduction in escape latency and swimming distance. Likewise, WO administration led to a notably reduced number of errors in training trial and an increased latency in testing trial when compared to the SCOP group in the step-down avoidance test,. Moreover, WO activated the cholinergic system of the brain by upregulating choline acetyltransferase activity and reducing acetylcholinesterase activity. These results suggest that WO has the potential to protect against memory decline in mice, offering a promising strategy for the prevention of memory-related disorders.

Unveiling the "hidden quality" of the walnut pellicle: a precious source of bioactive lipids.

Tree nut consumption has been widely associated with various health benefits, with walnuts, in particular, being linked with improved cardiovascular and neurological health. These benefits have been attributed to walnuts' vast array of phenolic antioxidants and abundant polyunsaturated fatty acids. However, recent studies have revealed unexpected clinical outcomes related to walnut consumption, which cannot be explained simply with the aforementioned molecular hallmarks. With the goal of discovering potential molecular sources of these unexplained clinical outcomes, an exploratory untargeted metabolomics analysis of the isolated walnut pellicle was conducted. This analysis revealed a myriad of unusual lipids, including oxylipins and endocannabinoids. These lipid classes, which are likely present in the pellicle to enhance the seeds' defenses due to their antimicrobial properties, also have known potent bioactivities as mammalian signaling molecules and homeostatic regulators. Given the potential value of this tissue for human health, with respect to its "bioactive" lipid fraction, we sought to quantify the amounts of these compounds in pellicle-enriched waste by-products of mechanized walnut processing in California. An impressive repertoire of these compounds was revealed in these matrices, and in notably significant concentrations. This discovery establishes these low-value agriculture wastes promising candidates for valorization and translation into high-value, health-promoting products; as these molecules represent a potential explanation for the unexpected clinical outcomes of walnut consumption. This "hidden quality" of the walnut pellicle may encourage further consumption of walnuts, and walnut industries may benefit from a revaluation of abundant pellicle-enriched waste streams, leading to increased sustainability and profitability through waste upcycling.

Asterias Rolleston starfish gonad lipids: A novel source of Omega-3 fatty acids - assessment of major components and their antioxidant activities

The major lipids and antioxidant activities of Asterias rolleston gonad lipids were evaluated systematically. Major lipids of A. Rolleston gonad lipids were triacylglycerols (TAGs) and phospholipids (PLs). Total lipids were composed of 15.62% of polyunsaturated fatty acids (PUFAs), and 40.81% of monounsaturated fatty acids (MUFAs). The most abundant PUFA were C20:5n-3 (EPA) (6.28%) and C22:6n-3 (DHA) (5.80%). Predominantly composed of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), polar lipids were rich in PUFAs and could contain up to 34.59% EPA and DHA, and PE and PI (phosphatidylinositol) were also found to be the main carriers of EPA and ARA (arachidonic acid) in polar lipids. The MUFA and PUFA of Sn-2 in TAG are 39.72% and 30.37%, respectively. A total of 64 TAG species were identified, with Eo-P-M, Eo-Eo-M, and M-M-Eo being the main TAGs components. Moreover, A. rollestoni gonad lipids exhibited potent radical scavenging activities and reducing power in a dose-dependent manner.

Abstract 1557: Loss of lncRNA XIST promote brain metastasis by reshaping tumor lipid metabolism via upregulation of ACSL4

Abstract Metastatic disease is the main cause of cancer death, and the brain is one of the major sites of breast tumor metastasis. The median survival of breast cancer patients who developed brain metastases (BrM) is less than a year even with the advanced treatment such as stereotactic radiosurgery (SRS). Regardless of high clinical significance, the pathological mechanism of brain metastasis is still poorly understood. Previously, we found that loss of lncRNA XIST robustly promote metastasis and specially brain metastasis in breast cancer. However, the underlying molecular mechanism was not fully understood. In following study, we found that loss of XIST has significantly altered lipid metabolism of breast cancer cells specifically increasing lipid droplet amount and PUFA incorporation. Instead of de novo syntheses, XISTlow cancer cells acquire fatty acid by uptake from exogenous. We found that one X-linked gene, Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) which are highly upregulated after loss of XIST is responsible for the altered lipid metabolism. ACSL4 activated the free polyunsaturated fatty acids (PUFAs) and lead to increased incorporation of PUFAs into phospholipids. On one hand, elevated ACLS4 expression leads to relative low PPAR pathway activation by decreasing the cellular free PUFA level which directly binds and activate PPAR. PPAR pathway is known to inhibit the expression of inflammatory cytokines which are important for cancer cells to establish brain metastasis. On the other hand, elevated ACSL4 expression enable cancer cells to metabolize the abundant PUFAs in the brain environment, thereby gaining survival advantage. However, increased PUFA incorporation into lipids especially phospholipids produce excess lipid ROS and sensitize cells to ferroptosis inducer such as RSL3. Our study has find out that brain microenvironment not only supports the outgrowth of XIST low cells by providing PUFAs for maintaining their metastatic properties but also sensitizes those cells to ferroptosis inducers, a potential therapy for treating this devastating disease. Citation Format: Yin Liu, Margaret R. Smith, Yuezhu Wang, Ralph D’Agostino, Jimmy Ruiz, Gregory L. Kucera, Lance D. Miller, Wencheng Li, Michael D. Chan, Michael Farris, Dawen Zhao, Fei Xing. Loss of lncRNA XIST promote brain metastasis by reshaping tumor lipid metabolism via upregulation of ACSL4 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1557.

Oleic Acid Metabolism in Response to Glucose in C. elegans.

A key response to glucose stress is an increased production of unsaturated fatty acids to balance the increase in saturated fatty acids in the membrane. The C. elegans homolog of stearoyl-CoA desaturase, FAT-7, introduces the first double bond into saturated C18 fatty acids yielding oleic acid, and is a critical regulatory point for surviving cold and glucose stress. Here, we incorporated 13C stable isotopes into the diet of nematodes and quantified the 13C-labelled fatty acid using GC-MS and HPLC/MS-MS to track its metabolic response to various concentrations of glucose. Previous work has analyzed the membrane composition of C. elegans when responding to mild glucose stress and showed few alterations in the overall fatty acid composition in the membrane. Here, in nematodes exposed to higher concentrations of glucose, a specific reduction in oleic acid and linoleic acid was observed. Using time courses and stable isotope tracing, the response of fatty acid metabolism to increasing levels of glucose stress is characterized, revealing the funneling of monounsaturated fatty acids to preserve the abundance of polyunsaturated fatty acids. Taken together, higher levels of glucose unveil a specific reduction in oleic and linolenic acid in the metabolic rewiring required to survive glucose stress.

Chemical composition, fatty acids, amino acids, minerals and vitamins profiles of Mithun (Bos frontalis) milk reared under semi-intensive system

This study examined the composition and nutritional value of milk produced by Mithun (Bos frontalis) reared under a semi-intensive model. The study analyzed the milk's chemical composition, fatty acids, amino acids, minerals, and vitamin profiles using standard methods. The results showed that fresh Mithun milk contained (Mean ± SEM) 7.3 ± 0.48 % fat, 10.28 ± 0.13 % solids-not-fat, 4.0 ± 0.05 % protein, 5.7 ± 0.08 % lactose, and had a density of 1.20 ± 0.01 g/mL. Gas chromatography analysis revealed that the milk contained 69.08 % saturated fatty acids and 30.82 % unsaturated fatty acids. The most abundant fatty acids were palmitic, oleic, stearic, and myristic acids, while linoleic 18:2 (n-6) and linolenic acids 18:3 (n-3) were the most abundant polyunsaturated fatty acids. The study also found that Mithun milk was rich in essential amino acids, with glutamic acid, lysine, proline, and isoleucine being the most abundant. In addition, Mithun milk was found to have a high concentration of vitamins A, D, and E, as well as calcium. The study concluded that Mithun milk could serve as a nutrient-dense food and contribute significantly to the nutritional security of North East India.

In vitro CRISPR screening uncovers CRTC3 as a regulator of IFN-γ-induced ferroptosis of hepatocellular carcinoma

Interferon-gamma (IFN-γ) exerts anti-tumor effects by inducing ferroptosis. Based on CRISPR/Cas9 knockout screening targeting genome-wide protein encoding genes in HepG2 and SK-Hep-1 cell lines, we found that cAMP response element-binding protein (CREB) regulated transcription coactivator 3 (CRTC3) protects tumor cells from drug-induced ferroptosis and significantly inhibits the efficacy of IFN-γ treatment in hepatocellular carcinoma (HCC). Mechanistically, CRTC3 knockout altered tumor cell lipid patterns and increased the abundance of polyunsaturated fatty acids (PUFAs), which enables lipid peroxidation and enhances the susceptibility of HCC cells to ferroptosis inducers. To scavenge for accumulated lipid peroxides (LPO) and maintain redox equilibrium, HCC cells up-regulate SLC7A11 and glutathione peroxidase 4 (GPx4) expressions to enhance the activities of glutamate-cystine antiporter (system xc−) and LPO clearance. As IFN-γ inhibiting system xc−, simultaneous treatment with IFN-γ disrupts the compensatory mechanism, and generates a synergistic effect with CRTC3 knockout to facilitate ferroptosis. Sensitizing effects of CRTC3 depletion were confirmed using typical ferroptosis inducers, including RSL3 and erastin. Sorafeinib, a commonly used target drug in HCC, was repeatedly reported as a ferroptosis inducer. We then conducted both in vitro and vivo experiments and demonstrated that CRTC3 depletion sensitized HCC cells to sorafenib treatment. In conclusion, CRTC3 is involved in the regulation of PUFAs metabolism and ferroptosis. Targeting CRTC3 signaling in combination with ferroptosis inducers present a viable approach for HCC treatment and overcoming drug resistance.

Ability of high fat diet to induce liver pathology correlates with the level of linoleic acid and Vitamin E in the diet.

Increased uptake of fat, such as through the ingestion of high fat diet (HFD), can lead to fatty liver diseases and metabolic syndrome. It is not clear whether certain fatty acids may be more pathogenic than others to the liver. Linoleic acid (LA) is the most abundant polyunsaturated fatty acid in the Western diet and its excessive consumption can lead to increased lipid peroxidation. We hypothesized that a high level of LA in HFD will contribute significantly to the hepatic steatosis and injury, whereas vitamin E (VIT-E) may reverse the effects from LA by inhibiting lipid peroxidation. To test this hypothesis, we fed mice with the following diets for 20 weeks: a standard low-fat diet (CHOW), HFD with a low level of LA (LOW-LA, 1% of energy from LA), HFD with a high level of LA (HI-LA, 8% of energy from LA), or HI-LA diet with VIT-E supplement (HI-LA + VIT-E). We found that the HI-LA diet resulted in more body weight gain, larger adipocyte area, and higher serum levels of triglycerides (TG) and free fatty acids (FFA) relative to the CHOW and LOW-LA diets. In mice fed with the HI-LA diet, severer hepatic steatosis was seen with higher levels of hepatic TG and FFA. Expression of genes related to lipid metabolism was altered in the liver by HI-LA diet, including fibroblast growth factor 21 (Fgf21), cluster of differentiation 36 (Cd36), stearoyl-CoA desaturase 1 (Scd1), and acyl-CoA oxidase 1 (Acox1). Liver injury, inflammation and fibrotic response were all enhanced in mice fed with the HI-LA diet when compared with the LOW-LA diet. Notably, addition of VIT-E supplement, which restores the proper VIT-E/PUFA ratio, significantly reduced the detrimental effects of the high level of LA. Taken together, our results suggest that a high level of LA and a low ratio of VIT-E/PUFA in HFD can contribute significantly to metabolic abnormalities and hepatic injury.

Variability in nutrient composition of the edible long-horned grasshopper (Ruspolia differens) in Uganda and its potential in alleviating food insecurity.

Ruspolia differens Serville (Orthoptera: Tettigonidae) is a highly nutritious and luxurious insect delicacy that is consumed as a food source in many African countries. However, the nutrient profile of R. differens in different geographical regions have received limited research interest. Here, we provide comprehensive evidence of geographical impact on the nutrient profile of R. differens and its potential to meet the recommended dietary intake of the population. Our results demonstrated that proximate composition, fatty acids, amino acids, minerals, vitamins, and flavonoid contents of R. differens collected from five districts in Uganda varied considerably. The crude protein (28-45%), crude fat (41-54%), and energy (582-644 Kj/100 g) contents of R. differens exceed that reported from animal origins. The highest crude protein, crude fat, and carbohydrate contents of R. differens were recorded in Kabale, Masaka, and Kampala, respectively. A total of 37 fatty acids were identified with linoleic acid (omega-6 fatty acid) being the most abundant polyunsaturated fatty acid in R. differens from Kabale, Masaka, and Mbarara. All essential amino acids were recorded in R. differens, particularly histidine with values exceeding the daily requirement for adults. Mineral and vitamin content differed significantly across the five districts. The highest quantity of flavonoids was recorded in R. differens from Hoima (484 mg/100 g). Our findings revealed that R. differens could be considered as functional food ingredients capable of supplying essential macro- and micronutrients that are critical in curbing the rising food insecurity and malnutrition in the regions.

The Arachidonic Acid Content of the Australian Diet Is Lower than Previously Estimated

Linoleic acid [18:2(n-6)] is the most abundant polyunsaturated fatty acid in the Western diet and is considered to be the primary source of tissue arachidonic acid [20:4(n-6)]. Dietary 20:4(n-6) may also contribute to tissue 20:4(n-6) levels in humans, but the extent of this contribution is unclear. We believe that literature estimates of 20:4(n-6) intake of 200–1000 mg/d are too high, possibly because of incorrect values in food composition tables where high amounts of 20:4(n-6) are recorded in margarines, some vegetable products and animal fat. We assessed the 20:4(n-6) content of common Australian foods and found that the 20:4(n-6) levels (on a 100-g edible basis), were 891 mg and 390 mg, respectively, for duck and chicken egg yolks, 294 mg for liver, 153 mg for kidney, 75 mg for skinless turkey, 56 mg for lean pork, 49 mg for lean lamb, 31 mg for chicken breast, 56 mg for chicken legs and 35 mg for lean beef. Eicosapentaenoic acid [20:5(n-3)] levels were <10 mg/100 g in chicken meat, turkey meat, emu meat and chicken eggs, whereas the values for 20:5(n-3) for beef, lamb, liver, kidney and duck egg yolk ranged from 11 to 138 mg/100 g food. Applying our current 20:4(n-6) measurements to previously determined food intakes of Australian adults determined in an Australiawide survey in 1983, we estimated the mean 20:4(n-6) intake for Australian adult males to be 130 mg/d and females 96 mg/d. Whether such intakes of dietary 20:4(n-6) make an important contribution to tissue 20:4(n-6) levels is uncertain.

Quantitative lipidomics analysis of changes in egg yolk lipids during spray-drying and subsequent accelerated storage

Egg yolks are rich in lipids that are easily altered during processing and storage. In this study, a liquid chromatography-tandem mass spectrometry strategy was used for quantitative lipidomics analysis of egg yolk after spray-drying processing and accelerated storage. Spray-drying treatment caused lipid oxidation (especially the oxidation of free fatty acids), potential hydrolysis of phospholipids, and alteration of the form of certain polyunsaturated fatty acids (docosahexaenoic acid, eicosapentaenoic acid, linolenic acid, and eicosatetraenoic acid) in egg yolk. These lipid alterations caused by the spray-drying process were further aggravated by the accelerated storage process. In detail, following storage, the abundance of free fatty acids, phosphatidic acid and phosphatidylethanolamine decreased further; and the abundance of polyunsaturated fatty acids in the form of triglycerides increased significantly. These results provide new insight into the mechanism underlying egg yolk property changes during spray-drying and storage, and offer valuable reference data for egg yolk powder promotion and application in food processing.

Docosahexaenoic Acid Ameliorates Contextual Fear Memory Deficits in the Tg2576 Alzheimer's Disease Mouse Model: Cellular and Molecular Correlates.

Docosahexaenoic acid (DHA), the most abundant polyunsaturated fatty acid in the brain, is essential for successful aging. In fact, epidemiological studies have demonstrated that increased intake of DHA might lower the risk for developing Alzheimer's disease (AD). These observations are supported by studies in animal models showing that DHA reduces synaptic pathology and memory deficits. Different mechanisms to explain these beneficial effects have been proposed; however, the molecular pathways involved are still unknown. In this study, to unravel the main underlying molecular mechanisms activated upon DHA treatment, the effect of a high dose of DHA on cognitive function and AD pathology was analyzed in aged Tg2576 mice and their wild-type littermates. Transcriptomic analysis of mice hippocampi using RNA sequencing was subsequently performed. Our results revealed that, through an amyloid-independent mechanism, DHA enhanced memory function and increased synapse formation only in the Tg2576 mice. Likewise, the IPA analysis demonstrated that essential neuronal functions related to synaptogenesis, neuritogenesis, the branching of neurites, the density of dendritic spines and the outgrowth of axons were upregulated upon-DHA treatment in Tg2576 mice. Our results suggest that memory function in APP mice is influenced by DHA intake; therefore, a high dose of daily DHA should be tested as a dietary supplement for AD dementia prevention.

Light modulates the lipidome of the photosynthetic sea slug Elysia timida

Long-term kleptoplasty, the capability to retain functional stolen chloroplasts (kleptoplasts) for several weeks to months, has been shown in a handful of Sacoglossa sea slugs. One of these sea slugs is Elysia timida, endemic to the Mediterranean, which retains functional chloroplasts of the macroalga Acetabularia acetabulum. To understand how light modulates the lipidome of E. timida, sea slug specimens were subjected to two different 4-week light treatments: regular light and quasi-dark conditions. Lipidomic analyses were performed by HILIC-HR-ESI-MS and MS/MS. Quasi-dark conditions caused a reduction in the amount of essential lipids for photosynthetic membranes, such as glycolipids, indicating high level of kleptoplast degradation under sub-optimal light conditions. However, maximum photosynthetic capacities (Fv/Fm) were identical in both light treatments (≈0.75), showing similar kleptoplast functionality and suggesting that older kleptoplasts were targeted for degradation. Although more stable, the phospholipidome showed differences between light treatments: the amount of certain lipid species of phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylglycerol (PG) decreased under quasi-dark conditions, while other lipid species of phosphatidylcholine (PC), PE and lyso-PE (LPE) increased. Quasi-dark conditions promoted a decrease in the relative abundance of polyunsaturated fatty acids. These results suggest a light-driven remodelling of the lipidome according to the functions of the different lipids and highlight the plasticity of polar lipids in the photosynthetic sea slug E. timida.

Dietary Fatty Acid Composition Impacts the Fatty Acid Profiles of Different Regions of the Bovine Brain.

Simple SummaryThe fatty acid composition of the mammalian brains varies by functional region, development, sex, and diet. In the current study, diets for growing female and castrated male bovines were supplemented with the calcium salts of palm or fish oil for 220 days. The cattle had unrestricted access to the supplements. At slaughter, the brains were removed from the cranium and blocked to the functional region. Analysis of the fatty acid content of the brain revealed they had similar fatty acid contents to other species including rodents and wild ungulates. Although diet differences across the regions were small, cattle supplemented with fish oil had greater contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with arachidonic acid levels being greater in palm-oil-supplemented cattle. Fatty acid contents across regions were similar to what has been reported for other species, and it suggests that a conserved lipid metabolism creates a uniform brain fatty acid profile.Fatty acid composition across functional brain regions was determined in bovine brains collected from cattle that were provided supplements of calcium salts containing either palm or fish oil. The Angus cattle were divided into two groups, with one group offered the supplement of calcium salts of palm oil and the other offered the calcium salts of fish oil (n = 5 females and n = 5 males/supplement) for 220 days. These supplements to the basal forage diet were provided ad libitum as a suspension in dried molasses. The fish oil exclusively provided eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3). The functional regions were dissected from the entire brains following commercial harvest. While the cattle provided diets supplemented with the calcium salts of palm oil had increased (p < 0.01) liver concentrations of C18:1 n-9, C18:2 n-6, and arachidonic acid, the fish-oil-supplemented cattle had greater (p < 0.01) concentrations of liver EPA, DHA, and C18:3 n-3. In the brain, DHA was the most abundant polyunsaturated fatty acid. In the amygdala, pons, frontal lobe, internal capsule, and sensory cortex, DHA concentrations were greater (p < 0.05) in the brains of the cattle fed fish oil. Differences among the supplements were small, indicating that brain DHA content is resistant to dietary change. Arachidonic acid and C22:4 n-6 concentrations were greater across the regions for the palm-oil-supplemented cattle. EPA and C22:5 n-3 concentrations were low, but they were greater across the regions for the cattle fed fish oil. The effects of sex were inconsistent. The fatty acid profiles of the brain regions differed by diet, but they were similar to the contents reported for other species.

Nasopharyngeal lipidomic endotypes of infants with bronchiolitis and risk of childhood asthma: a multicentre prospective study

BackgroundBronchiolitis is the leading cause of hospitalisation of US infants and an important risk factor for childhood asthma. Recent evidence suggests that bronchiolitis is clinically heterogeneous. We sought to derive...

Biochemical composition, nutritional value and socio-economic impacts of the invasive crab Callinectes sapidus Rathbun, 1896 in central Mediterranean Sea

The Atlantic crab Callinectes sapidus was recently recorded in Tunisia and presents an invasive behavior. This study aims to evaluate its socio-economic impacts on small-scale fisheries and to analyze variations in chemical composition, fatty acids profile, and nutritive value according to sex and edible tissues. Socio-economic surveys via face-to-face revealed a decline in fishermen’s income from 15% to even 70% (damages on fishing nets and catches). Muscles yield of Callinectes sapidus ranged between 36.07±2.84% and 42.83±6.53% respectively for females and males. All the analyzed tissues contained high protein contents (&gt; 23%) and particularly cephalothorax muscles reaching 27.05±0.16%. This new exotic food can be recommended in low fat diets since it contained less than 5% of total fats. The fatty acid profile was dominated by the polyunsaturated fatty acids (PUFA) for both sexes and all the analyzed tissues. Eicosapentaenoic acid, docosahexaenoic acid and arachidonic acid were the most abundant PUFA in all tissues ranging respectively from 9.31% to 15.64%, from 8.74% to 13.78% and between 6.81% and 9.21%. All the nutritional indexes of lipids indicated that this crab could be beneficial for human health. In addition, it constitutes a new marine resource with high economic opportunity.

Intranasal Administration of Nanovectorized Docosahexaenoic Acid (DHA) Improves Cognitive Function in Two Complementary Mouse Models of Alzheimer's Disease.

Polyunsaturated fatty acids (PUFAs) are a class of fatty acids that are closely associated with the development and function of the brain. The most abundant PUFA is docosahexaenoic acid (DHA, 22:6 n-3). In humans, low plasmatic concentrations of DHA have been associated with impaired cognitive function, low hippocampal volumes, and increased amyloid deposition in the brain. Several studies have reported reduced brain DHA concentrations in Alzheimer’s disease (AD) patients’ brains. Although a number of epidemiological studies suggest that dietary DHA consumption may protect the elderly from developing cognitive impairment or dementia including AD, several review articles report an inconclusive association between omega-3 PUFAs intake and cognitive decline. The source of these inconsistencies might be because DHA is highly oxidizable and its accessibility to the brain is limited by the blood–brain barrier. Thus, there is a pressing need for new strategies to improve DHA brain supply. In the present study, we show for the first time that the intranasal administration of nanovectorized DHA reduces Tau phosphorylation and restores cognitive functions in two complementary murine models of AD. These results pave the way for the development of a new approach to target the brain with DHA for the prevention or treatment of this devastating disease.

Deuterated docosahexaenoic acid protects against oxidative stress and geographic atrophy-like retinal degeneration in a mouse model with iron overload.

Oxidative stress plays a central role in age‐related macular degeneration (AMD). Iron, a potent generator of hydroxyl radicals through the Fenton reaction, has been implicated in AMD. One easily oxidized molecule is docosahexaenoic acid (DHA), the most abundant polyunsaturated fatty acid in photoreceptor membranes. Oxidation of DHA produces toxic oxidation products including carboxyethylpyrrole (CEP) adducts, which are increased in the retinas of AMD patients. In this study, we hypothesized that deuterium substitution on the bis‐allylic sites of DHA in photoreceptor membranes could prevent iron‐induced retinal degeneration by inhibiting oxidative stress and lipid peroxidation. Mice were fed with either DHA deuterated at the oxidation‐prone positions (D‐DHA) or control natural DHA and then given an intravitreal injection of iron or control saline. Orally administered D‐DHA caused a dose‐dependent increase in D‐DHA levels in the neural retina and retinal pigment epithelium (RPE) as measured by mass spectrometry. At 1 week after iron injection, D‐DHA provided nearly complete protection against iron‐induced retinal autofluorescence and retinal degeneration, as determined by in vivo imaging, electroretinography, and histology. Iron injection resulted in carboxyethylpyrrole conjugate immunoreactivity in photoreceptors and RPE in mice fed with natural DHA but not D‐DHA. Quantitative PCR results were consistent with iron‐induced oxidative stress, inflammation, and retinal cell death in mice fed with natural DHA but not D‐DHA. Taken together, our findings suggest that DHA oxidation is central to the pathogenesis of iron‐induced retinal degeneration. They also provide preclinical evidence that dosing with D‐DHA could be a viable therapeutic strategy for retinal diseases involving oxidative stress.

Antioxidant potential and fatty acid profile of fish fillet: effects of season and fish species.

The objectives of the present study were to investigate the effect of season and fish species on the antioxidant capacity, fatty acids profile, and vitamin E content of fish fillets from Aras River. The antioxidant potential of hydrophilic and lipophilic extracts of fish fillets was evaluated. The fillet extracts of zander and bream in summer and common carp in winter had the highest antioxidant activity. Palmitic and oleic acids were the major saturated (SFA) and monounsaturated (MUFA) fatty acids, respectively. The fatty acids C22:6n3 and C20:5n3 were the most abundant polyunsaturated (PUFA) fatty acids in all the fishes. In summer, the highest levels of SFA (44.09), total PUFA (25.97), n3 PUFA (20.71) and n3/n6 ratio (4) were found in zander. In winter, the highest amounts of total PUFA and n3 PUFA were determined in silver carp, followed by zander. The highest n3/n6 ratio was also found in silver carp. The ratio of PUFA/SFA was higher in winter than in summer for all the fishes. Vitamin E content of fishes was largely varied. In conclusion, seasonal variation changed the antioxidant potential and fatty acid composition of fish fillets. Aras River fishes, especially zander, possess excellent antioxidant activity and high nutritional quality.

Physical-chemical characteristics of “Red Meal”, a novel non-defatted additive in the fish feed from cracked biomass of Haematococcus pluvialis

Haematococcus pluvialis (HP) astaxanthin is widely used in the aquaculture industry to improve the pigmentation of salmon, shrimp, and egg yolk, also this pigment has an important physiological role in animal health and reproduction. The “Red Meal” (RM) is the whole cracked biomass of HP homogenized in vegetable oil to form a non-defatted meal product. This study aimed to determine the physical and chemical characterization of a novel non-defatted meal feed product (“Red Meal”, so-called by the production company). RM behavior was shear-thickening fluid at 40 °C, whereas, at 5, 10, 25, 30, and 60 °C shear-thinning fluid was observed; thus, viscosity was decreased with the increase of shear rate. On the other hand, the RM presented a 14.5 ± 0.1, 62.5 ± 9.6, 17.6 ± 2.7, 3.7 ± 0.1, and 1.5 ± 0.4% of protein, lipids, carbohydrates, ash, and moisture, respectively. The fatty acid profile of RM was 51.1% of linoleic acid C18:2(c9c12), 25.4% of oleic acid C18:1(c9), 9.5% of palmitic acid C16:0, 7.9% of heneicosylic acid C21:1%, and 2.8% of stearic acid C18:0, where the linoleic acid and oleic acid represented 76.5% of the total fatty acid profile. Additionally, the most abundant polyunsaturated fatty acid was ω-6 (51.40%), followed by ω-9 (25.40%); whereas a small amount of omega-3 (0.88%) was reported. The total carotenoid content in the RM was 17.19 mg/g of dry biomass; in which the main pigment was astaxanthin esters (55.13%), followed by lutein (5.67%), free astaxanthin (5.54%), β-carotene (2.76%), and canthaxanthin (2.65%).