Docosahexaenoic Acid Research Articles

Structural basis for the access and binding of resolvin D1 (RvD1) to formyl peptide receptor 2 (FPR2/ALX), a class A GPCR.

Inflammation is essential to the body's defense against tissue injury and microbial invasion. However, uncontrolled inflammation is highly detrimental and can result in chronic inflammatory diseases such as asthma, cancer, obesity, and diabetes. An increasing body of evidence suggests that specialized pro-resolving lipid mediators (SPMs), such as resolvins, are actively involved in critical cellular events that drive the resolution of inflammation and a return to homeostasis. An imbalance caused by insufficient SPMs can result in the unsuccessful resolution of inflammation. The D-series resolvins (metabolites of docosahexaenoic acid), such as resolvin D1 (RvD1) and resolvin D2 (RvD2), carry out their pro-resolving functions by directly binding to class A G protein-coupled receptors FPR2/ALXR and GPR32, and GPR18, respectively. We recently demonstrated that RvD1 and RvD2 preferentially partition and accumulate at the polar headgroup regions of the membrane. However, the mechanistic detail of how RvD1 gains access to the FPR2 binding site from a surrounding membrane environment remains unknown. In this study, we used classical MD and well-tempered metadynamics simulations to examine the structural basis for the access and binding of RvD1 to its target receptor from aqueous and membrane environments. The results offer valuable insights into the access path, potential binding pose, and key residue interactions essential for the access and binding of RvD1 to FPR2/ALXR and may help in identifying small molecule therapeutics as a possible treatment for inflammatory disorders.

Recent advances on the physiological and pathophysiological roles of polyunsaturated fatty acids and their biosynthetic pathway

Polyunsaturated fatty acids (PUFAs)—fatty acids containing multiple double bonds within their carbon chain—are an indispensable component of the cell membrane. PUFAs, including the omega-6 PUFA arachidonic acid (ARA; C20:4n-6) and the omega-3 PUFAs eicosapentaenoic acid (EPA; C20:5n-3) and docosahexaenoic acid (DHA; C22:6n-3), have been implicated in various (patho)physiological events. These PUFAs are either obtained from the diet or biosynthesized from the essential fatty acids linoleic acid (LA; C18:2n-6) and α-linolenic acid (ALA; C18:3n-3) via enzymatic reactions that are catalyzed by fatty acid elongases (ELOVL2 and ELOVL5) and fatty acid desaturases (FADS1 and FADS2). In this review, we summarize the recent literature studying the role of PUFAs, placing a special emphasis on the newly discovered functions of PUFAs and their biosynthetic pathway as revealed by studies using animal models targeting the PUFA biosynthetic pathway and genetic approaches including genome-wide association studies.

Analyzing eight Turkish macroalgae: Fatty acids, proteins, and in silico biological activity profiles

AbstractThis study investigated the fatty acid (FA) compositions and proteins’ molecular weight profiles (MWP) of eight macroalgae species collected from the Antalya and Çanakkale in Turkiye: three red (Liagora viscida, Laurencia obtusa, Palisada perforata), three brown (Stypopodium schimperi, Cladostephus spongiosus, Halopteris scoparia), and two green (Caulerpa scalpelliformis, Penicillus capitatus). The potential bioactivities of the FAs were evaluated by in silico studies, focusing on anti‐cholinesterase, antioxidant, and cardioprotective effects. The predominant FA across all species was palmitic acid comprising over 50% of total FAs in most species. Docosahexaenoic acid (DHA) was abundant in seven of the eight species. Significant variations in MWPs were observed among species, with values ranging from <2532 to >67 000 Da. Brown algae generally exhibited higher MWP levels compared to red and green algae which showed distinctive profiles. In silico studies revealed that DHA exhibited the strongest binding affinity toward lipoxygenase acetylcholinesterase and butyrylcholinesterase enzymes with −8.829, −10.636, and −7.984 kcal mol−1 docking scores, respectively. DHA demonstrated significant interactions with key residues, forming hydrogen bonds critical for enzymatic inhibition and potential therapeutic effects. Molecular dynamics simulations confirmed the stability of DHA–protein complexes with low root mean square deviation and root mean square fluctuation values. This comprehensive analysis underscores the nutritional richness and potential bioactivity of macroalgae, particularly in terms of FA composition and protein profiles. The findings suggest that macroalgae, rich in DHA and other beneficial FAs, hold promise for pharmaceutical and nutraceutical applications, warranting further exploration into their therapeutic potential.Practical Applications: This study explores the fatty acid compositions and protein MWPs of eight macroalgae from Turkey's coasts. The findings suggest potential applications in aquaculture feeds and functional foods. Notably, DHA stands out for its antioxidant, cardioprotective, and cholinesterase inhibitor properties, making these macroalgae promising sources for obtaining DHA. The research supports practical applications in developing nutritional supplements, pharmaceuticals, and aquaculture practices, harnessing the bioactive potential of these marine resources for human health and industry.

Discarded blue mussel (Mytilus edulis): a feed ingredient that maintains growth performance of juvenile gilthead seabream (Sparus aurata) while fishmeal and fish oil are removed

ABSTRACT The total substitution of fishmeal (FM) and fish oil (FO) with sustainable feed ingredients, while maintaining acceptable growth performances and fish composition, is a challenge. Mussels have a high protein content, with essential amino acid and fatty acid (FA) profiles similar to those of FM. This study aimed to assess the potential to rear gilthead seabream (Sparus aurata) on a plant-based feed (without FM and FO) to which mussels were added. Subsequent effects on growth performance, protein content, and FA concentrations were studied. Juvenile gilthead seabream were reared for 46 days in water temperature of 21°C, in a recirculated aquaculture system composed of three fish tanks, each corresponding to one treatment: in the FMFO treatment, 342 fish were fed a commercial feed that contained FM and FO; in the plant-based feed (PBF) treatment, 345 fish were fed an experimental feed that contained only plant-based ingredients; in the mussel feed (MF) treatment, 342 fish were fed the feed from PBF supplemented with fresh mussel flesh from which the shells had been removed. Fish weighed a mean of 6.7 ± 1.3 g at stocking in each treatment. At harvest, the mean weight of fish from FMFO and MF were significantly different (23.1 ± 4.3 and 23.1 ± 5.2 g, respectively) than that from PBF (15.5 ± 3.6 g) (p < .05). Compared to the feed from FMFO, the feed from PBF decreased the percentages of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and saturated FA (14:0, 16:0) in fish, but increased those of 18:1, 18:2 n-6 and 18:3 n-3 FA. Compared to the feed from PBF, the feed from MF increased the EPA+DHA concentration in fish by 21%. Thus, adding fresh mussels to a plant-based feed yielded similar growth performances and survival rate as a commercial feed. It also improved the FA composition of fish compared to that of fish fed a plant-based feed.

Differential Effect of Omega-3 Fatty Acids on Platelet Inhibition by Antiplatelet Drugs In Vitro.

The omega-3 polyunsaturated fatty acids (PUFAs) Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) exert multiple cardioprotective effects, influencing inflammation, platelet activation, endothelial function and lipid metabolism, besides their well-established triglyceride lowering properties. It is not uncommon for omega-3 PUFAs to be prescribed for hypertriglyceridemia, alongside antiplatelet therapy in cardiovascular disease (CVD) patients. In this regard, we studied the effect of EPA and DHA, in combination with antiplatelet drugs, in platelet aggregation and P-selectin and αIIbβ3 membrane expression. The antiplatelet drugs aspirin and triflusal, inhibitors of cyclooxygenase-1 (COX-1); ticagrelor, an inhibitor of the receptor P2Y12; vorapaxar, an inhibitor of the PAR-1 receptor, were combined with DHA or EPA and evaluated against in vitro platelet aggregation induced by agonists arachidonic acid (AA), adenosine diphosphate (ADP) and TRAP-6. We further investigated procaspase-activating compound 1 (PAC-1) binding and P-selectin membrane expression in platelets stimulated with ADP and TRAP-6. Both DHA and EPA displayed a dose-dependent inhibitory effect on platelet aggregation induced by AA, ADP and TRAP-6. In platelet aggregation induced by AA, DHA significantly improved acetylsalicylic acid (ASA) and triflusal's inhibitory activity, while EPA enhanced the inhibitory effect of ASA. In combination with EPA, ASA and ticagrelor expressed an increased inhibitory effect towards ADP-induced platelet activation. Both fatty acids could not improve the inhibitory effect of vorapaxar on AA- and ADP-induced platelet aggregation. In the presence of EPA, all antiplatelet drugs displayed a stronger inhibitory effect towards TRAP-6-induced platelet activation. Both omega-3 PUFAs inhibited the membrane expression of αIIbβ3, though they had no effect on P-selectin expression induced by ADP or TRAP-6. The antiplatelet drugs exhibited heterogeneity regarding their effect on P-selectin and αIIbβ3 membrane expression, while both omega-3 PUFAs inhibited the membrane expression of αIIbβ3, though had no effect on P-selectin expression induced by ADP or TRAP-6. The combinatory effect of DHA and EPA with the antiplatelet drugs did not result in enhanced inhibitory activity compared to the sum of the individual effects of each component.

Dietary EPA and DHA enrichment of a high fat diet during doxorubicin-based chemotherapy attenuated neuroinflammatory gene expression in the brain of C57bl/6 ovariectomized mice

Chemotherapy agents in breast cancer are associated with chemotherapy-related cognitive impairments (CRCI). Mechanisms are not fully clear, but alterations of glucose and lipid metabolism, neuroinflammation and neurodegeneration may contribute to CRCI. The aim of this study was to investigate the combined effects of a high fat (HF) diet combined with doxorubicin-based chemotherapy on glucose and lipid metabolism, neuroinflammation, and neurodegeneration in mice. Additionally, we examined the therapeutic potential of dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to attenuate these effects. Female C57Bl/6 mice (n = 42) were fed HF, HFn-3 (2 % kcals as EPA + DHA) or Low Fat (LF) diets for seven weeks, with and without chemotherapy. In this study, two chemotherapy injections led to weight and body fat loss associated with a decrease in insulin resistance measured by HOMA-IR. HOMA-IR was significantly greater in HF versus LF groups; but HOMA-IR in HFn-3 group did not significantly differ from either HF or LF groups. Chemotherapy resulted in higher brain concentrations of the inflammatory chemokine KC/GRO. Compared to LF diet plus chemotherapy, HF diet plus chemotherapy upregulated multiple genes involved in neuroinflammation and neurodegeneration pathways. HFn-3 diet plus chemotherapy attenuated gene expression by downregulating multiple genes involved in neuroinflammation and blood brain barrier regulation, including Mapkapk2, Aqp4, and s100b, and upregulating Kcnb1 and Atxn3, genes involved in reduction of oxidative stress and anxiety, respectively. Overall, a HF diet combined with chemotherapy is associated with neuroinflammatory and neurodegenerative gene expression changes in this mouse model; dietary enrichment of EPA and DHA attenuated these effects. Further studies are needed to understand how diet impacts behavioral outcomes of CRCI.

In vitro digestion study comparing a predigested glycerolysis product versus long-chain polyunsaturated fatty acid-rich oils (LCPUFA) as a strategy for administering LCPUFA to preterm neonates

Background & aimsMaintaining an adequate supply of arachidonic acid (ARA) and docosahexaenoic acid (DHA) is essential for optimal growth of preterm infants. This study aims to evaluate and compare the digestibility and bioaccessibility of ARA and DHA oils compared to their predigested product through an in vitro digestion model. MethodsAn in vitro gastrointestinal digestion model was used in two stages: gastric digestion and intestinal digestion. Samples of two polyunsaturated rich oils (ARA and DHA oils) and their predigested product (2:1, ARA: DHA) produced by enzymatic glycerolysis have been digested for 120 min. The final digestion product obtained was composed of three phases: an upper oily phase (OP) containing the undigested species, an intermediate micellar phase (MP) containing digested and bioaccessible lipids, and a precipitate phase (PP) with insoluble compounds. The reaction was monitored by taking aliquots and their subsequent lipid extraction and analysis. ResultsPoorer digestibility for ARA and DHA oils was observed based on the percentage of the oily phase (26.7% and 20%, respectively) found compared to the glycerolysis product (GP) oily phase (13.9%). The highest micellar phase was found in the GP (approx. 83%). On the other hand, the monoglyceride (MAG) content was lower in the digestion product (DP) from ARA and DHA oils, 4.3% and 9.2%, respectively, compared to the MAG observed in the DP of GP (15%). ConclusionConsidering the percentage of oily phase, micellar phase, and the MAG content, it can be concluded that the GP is more digestible and ARA and DHA are more bioaccessible than in its precursor oils.

A Clinicians Guide to Recommending Common Cholesterol-Lowering Dietary Supplements.

The US dietary supplement (DS) market has expanded exponentially since 1994, with an estimated 50,000-80,000 individual products currently available. Many DS claim cholesterol or cardiovascular benefits. Overall, well-designed randomized controlled trials (RCTs) with DS are lacking, while studies with favorable results are commonly performed outside of the USA, resulting in inconsistent findings. The expansion of the DS market has limited the ability of the Food and Drug Administration to regulate and prevent substandard products. Eicosapentaenoic acid and docosahexaenoic acid are components of DS fish oil. Recent RCTs utilizing prescription fish oil have provided mixed findings and small but significant safety concerns. Hence, the role of DS fish oil is limited and no longer recommended by major cardiovascular guidelines. Concerns have also been observed from RCTs utilizing prescription niacin, resulting in a negligible role for DS niacin in lipid management. Red yeast rice has demonstrated significant low-density lipoprotein cholesterol (LDL-C) reductions in studies performed worldwide, including the USA. However, quality concerns and inconsistent study results have been reported on multiple occasions. Other common DS have produced modest reductions in LDL-C and may provide other cardiometabolic benefits, including garlic, phytosterols, psyllium, and berberine. Yet inconsistent study results and quality concerns continue to be reported for most. Nonetheless, there is a need for alternative therapies that can safely and effectively reduce cardiovascular risk. However, until DS routinely match label claims and are free of contaminants, the agents have a limited role in clinical practice.

Fads2 knockout mice reveal that ALA prevention of hepatic steatosis is dependent on delta-6 desaturase activity

The production of the omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from alpha-linolenic acid (ALA) relies on the delta-6 desaturase (D6D) enzyme encoded by the Fads2 gene. While EPA and DHA reduce hepatic triacylglycerol (TAG) storage and regulate lipogenesis, the independent impact of ALA is less understood. To address this gap in knowledge, hepatic fatty acid metabolism was investigated in male wild-type (WT) and Fads2 knockout (KO) mice fed diets (16% kcal from fat) containing either lard (no n-3 LCPUFA), flaxseed oil (ALA-rich), or menhaden oil (EPA/DHA rich) for 21 weeks. Fat content and composition, as well as markers of lipogenesis, glyceroneogenesis, and TAG synthesis, were analyzed using histology, gas chromatography, and reverse transcription quantitative PCR (RT-qPCR). Mice fed the menhaden diet had significantly lower hepatic TAG compared to both lard- and flax-fed mice, concomitant with changes in n-3 and n-6 LCPUFA in both TAG and phospholipid (PL) fractions (all P < 0.05). Flax-fed WT mice had lower liver TAG content compared to their KO counterparts. Menhaden-fed mice had significantly lower expression of key lipogenic (Scd1, Srebp-1c, Fasn, Fads1, and Fads2), glyceroneogenic (Pck1), and TAG synthesis (Agpat3) genes compared to lard, with flax-fed mice showing some intermediate effects. Gene expression effects were independent of D6D activity, since no differences were detected between WT and KO mice fed the same diet. This study demonstrates that EPA/DHA and not ALA itself is critical for the prevention of hepatic steatosis.

Plasma levels of EPA and DHA after ingestion of a single dose of EPA and DHA ethyl esters

AbstractOmega‐3 polyunsaturated fatty acids (n3 PUFA), specifically eicosapentaenoic acid (EPA, 20:5n3), and docosahexaenoic acid (DHA, 22:6n3), are essential for maintaining health. To better understand their biology, it is important to define their bioavailability. The aim of this cross‐over study was to investigate and compare the acute effects on plasma EPA and DHA levels after single doses of EPA oil (99% pure) and DHA (97% pure) ethyl esters. Twelve men aged 20–40 years with a body‐mass‐index of 20–27 kg/m2 and low fish consumption were recruited. Several measures (e.g., 4‐week run‐in period, standardized diet, and blood collection protocols) were taken to reduce the inter‐individual variability of plasma fatty acids levels. Using a cross‐over design, the subjects received 2.2 g of EPA in the first test period and 2.3 g of DHA in the second. The test periods were separated by 2 weeks. Blood samples were taken before dosing and after 2, 4, 6, 8, 12, 24, 48, and 72 h. The mean ± SE maximum concentrations for EPA were higher than for DHA (115 ± 11 μg/mL vs. 86 ± 12 μg/mL; p = 0.05). The mean ± SE incremented area under the plasma concentration curve over 72 h for EPA (2461 ± 279 μg/mL) was 2.4 times higher (p &lt; 0.001) than that for DHA (1021 ± 170 μg/mL). The mean ± SE half‐life was for EPA and DHA was 45 ± 8 and 66 ± 12 h. Our results indicate that EPA administration in single doses leads to higher circulating plasma levels of EPA compared to an effect of an equivalent dose of DHA on DHA plasma levels.

IR spectra simulations by anharmonic DFT and CDFT-saturated and unsaturated fatty acids of Siberian sturgeon (Acipenser baerii Brandt,1869)

The Siberian sturgeon is one of the most remarkable species in the field of aquatic biology which also has ecological importance, commercial significance, and nutritional characteristics. The purpose of this study is to determine the fatty acid content of different organs of Siberian sturgeon through both theoretical and experimental techniques to compare oxidative stability of the samples in terms of fatty acid profile. For this purpose, the fatty acid content of flesh, brain, caviar and liver of sturgeon was determined by gas chromatography and the middle infrared spectra of tissues were collected by an infrared spectrofotometer. The fatty acid content of samples was also computed by anharmonic DFT and CDFT calculations using IR spectra. Oleic acid was the most abundant fatty acid in all tissues. All tissues accumulated by docosahexanoic, eicosapentanoic and linolenic acids. The PCA model was able to classified the tissues with respect to fatty acid contents. Comprehensive anharmonic DFT calculations were performed to better understand the fatty acid of samples at the atomistic level and to predict the spectra of more complex food samples with varying fatty acid compositions. Oxidative stabilities of fatty acids were also investigated through Conceptual DFT based computations. Maximum Hardness and Minimum Electrophilicity Principles accurately predicted saturated and unsaturated fatty acids of sturgeon as the experimental data revealed.

The N-3 polyunsaturated fatty acids supplementation to prevent depression recurrence in patients with late-life depression: A 52-week double-blind, placebo-controlled trial

BackgroundReports on the efficacy of omega-3 fatty acids (n-3 PUFAs) for the treatment of late-life depression (LLD) are mixed, and most studies focus on the modification of depressive symptoms rather than depression prevention. The aim of the present study was to investigate the efficacy of n-3 PUFAs in preventing depressive recurrence in patients with late-life depression. In addition, we investigated the effects of n-3 PUFAs on changes in depressive and anxiety symptoms and inflammatory markers in LLD. MethodsA 52-week, double-blind, randomized, controlled trial was conducted. We enrolled a total of 39 euthymic patients with LLD. They were randomized to receive either n-3 PUFAs (1.2 g per day of eicosapentaenoic acid and 1 g of docosahexaenoic acid) or placebo for 52 weeks. Recurrence of depression and severity of depression symptoms were assessed at baseline and weeks 4, 8, 16, 24, 32, 40, and 52. ResultsA total of 39 patients completed the trial with 19 in the n-3 PUFAs group and 20 in the placebo group. Cox proportional hazard regression indicated that n-3 PUFAs had significant protective effect on depression recurrence (Hazard Ratio: 0.295, 95 % Confidence Interval: 0.093–0.931, p value =0.037). But n-3 PUFAs intervention had no significant effect in reducing depressive or anxiety symptoms, inflammatory markers over the placebo group. LimitationThe results should be interpreted with consideration of the modest sample size. ConclusionThese findings suggest that n-3 PUFAs may have a prophylactic effect in currently euthymic patients with LLD.

Enhancing the nutritional values of egg yolks of laying hens by different dietary sources of omega-3 fatty acids, vitamin e and trace elements

The present study aims to investigate the effect of whole flaxseed (WFS), fish oil (FO), and different sources of Se, Zn, and Fe on lipid metabolites, antioxidant status, immunity, egg yolks’ minerals (Se, Zn and Fe) and fatty acids and eggs’ lipid and health index in laying hens. A total of 144 hens were divided into 6 groups with 6 replicated of 4 hens each. The laying hens were fed diets containing 0, 7.5 % whole flaxseed (WFS)+1.5 % fish oil (FO), 7.5 %WFS+1.5 % FO+175 mg kg-1 vitamin E (VE), 7.5 %WFS+1.5 % FO+ 175 mg kg-1 VE +inorganic sources of Se, Zn, and Fe (ISeZnFe), 7.5 %WFS+1.5 % FO+175 mg kg-1 VE+ organic sources of Se, Zn, and Fe (OSeZnFe) and 7.5 %WFS+1.5 % FO+ 175 mg kg-1 VE +nano-source of Se, Zn, and Fe (NSeZnFe) from 40 to 50 weeks of age. Results clarified that incorporation of 7.5 %WFS+1.5 %FO+VE+OSeZnFe or 7.5 %WFS+1.5 %FO+VE+NSeZnFe increased serum concentration of HDL-cholesterol and HDL/LDL ratio, while reduced LDL-cholesterol and the hypercholesteremia index (RHCH) in comparison with control. Dietary 7.5 %WFS+1.5 %FO+VE+OSeZnFe or 7.5 %WFS+1.5 %FO+VE+NSeZnFe increased concentrations of total antioxidants capacity and vitamin E and reduced concentrations of malonaldehyde (MDA) in blood serum and egg contents. Interestingly, dietary inclusion of 7.5 %WFS+1.5 %FO+VE+OSeZnFe, or 7.5 %WFS+1.5 %FO+VE+NSeZnFe increased α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFAs concentrations in egg yolk, while reduced arachidonic acid (ARA) in the egg yolks, whereas n-6/n-3 PUFAs ratio was decreased significantly. Moreover, incorporation of 7.5 %WFS+1.5 %FO+VE+OSeZnFe, or 7.5 %WFS+1.5 %FO+VE+NSeZnFe improved egg health indices. It might be concluded that, inclusion of 7.5 %WFS+1.5 %FO+VE+OSeZnFe, or 7.5 %WFS+1.5 %FO+VE+NSeZnFe in hens’ diets had a positive effect on antioxidative properties in blood serum and eggs yolks contents; at the same time, it improved the egg yolk lipids, fatty acids and its related health and nutritional indices.

Plasma fatty acid levels and risk of non-small cell lung cancer: a large-scale prospective cohort study.

Non-small cell lung cancer (NSCLC) ranks among the most prevalent and lethal malignancies globally. Fatty acids (FAs) play a significant role in diverse physiological and pathological mechanisms, yet their precise involvement in NSCLC remains poorly understood. This study utilized a large-scale prospective cohort of 249,132 participants, observed over an average of 12 years, to investigate the relationship between different FAs and NSCLC risk. Analytical approaches included Cox proportional hazards regression, Kaplan-Meier survival analysis, accelerated failure time (AFT) modeling, and restricted cubic spline (RCS) analysis. During the follow-up period, 1,460 participants were diagnosed with NSCLC. Cox regression analysis demonstrated that elevated levels of docosahexaenoic acid (DHA), linoleic acid (LA), and omega-3 were inversely associated with NSCLC risk. Kaplan-Meier curves, along with AFT models, corroborated that elevated concentrations of DHA and LA significantly delayed NSCLC onset. Additionally, RCS analysis uncovered nuanced dose-response relationships between these FAs and NSCLC. Stratified analyses highlighted variability based on smoking status, gender, and body mass index subgroups. The concentration of specific FAs exhibits a significant association with NSCLC risk. These results offer a foundation for devising dietary FA composition adjustments aimed at reducing NSCLC risk.

Effect of refrigeration and reheating on the lipid oxidation and volatile compounds in silver carp surimi gels.

As unsaturated and saturated aldehydes, ketones are known to be responsible for off-odors in surimi products, and they are mainly derived from lipid oxidation. Because surimi-based products are rich in unsaturated fatty acids, they are prone to producing off-odors during the refrigeration and reheating processes, which are common treatments for leftovers. The present study investigated the color, lipid oxidation productions, fatty acid profiles and volatile components in surimi gels during refrigeration at 4 °C for 3 days with multiple reheating. The results revealed that the accumulation rate of hydroperoxides was higher in the refrigeration stage, whereas the decomposition rate was higher during reheating in surimi gels. Both refrigeration and reheating treatments promoted conjugated diene values, acid values and carbonyl values. Nevertheless, reheating treatment decreased tohiobarbituric acid reactive substances and whiteness. The contents of unsaturated fatty acids, especially α-linolenic acid, arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid, were reduced, whereas the contents of saturated fatty acids increased during refrigeration and multiple reheating. The unsaturated fatty acids were lost as a result of their oxidative deterioration. The volatile components profile showed that the accumulation of volatile components mainly occurred in the refrigeration stage. Multivariate data analysis was utilized to further clarify whether the off-odors in surimi gels were mainly generated in refrigeration. Refrigeration and reheating both contributed to lipid oxidation and the generation of volatile compounds in surimi gels, but the off-odors were mainly generated during refrigeration. This research provides a novel understanding of the formation of food odors in processing. © 2024 Society of Chemical Industry.

Biochemical profile of the native seaweed fly Fucellia maritima (Haliday, 1838) (Diptera: Anthomyiidae) reared on five different substrates

Abstract The sustainability of aquaculture production is crucial for the industry’s long-term viability. Diversification of feed ingredients is a key component in achieving this sustainability. Considered a promising alternative to traditional feed ingredients, terrestrial insect meals often lack sufficient n-3 polyunsaturated fatty acids (PUFA). This study explores the potential of marine insect species, specifically evaluating the influence of five different substrates on the growth and composition of the European native seaweed fly, Fucellia maritima. The substrates tested include a brown seaweed (Fucus sp.), a green seaweed (Ulva sp.), a red seaweed (the invasive Agarophyton vermiculophyllum), the invasive freshwater hyacinth (Eichhornia crassipes), and fish processing waste (codfish Gadus morhua frames). Results show no significant difference in the number of individuals per substrate, although Fucus sp. had a higher total number of individuals completing their life cycle. In contrast, feeding on codfish frames resulted in a lower number of completed life cycles, while E. crassipes led to no survival. Protein content in adult flies ranged from 55.2% to 56.7%, and in pupae, it ranged from 46.1% to 48.7% across different feeding substrates. Notably, pupae fed with Ulva sp., exhibited the highest protein content at 48.7%. Lipid content in adult flies ranged from 10.0% to 13.0%, while in pupae, it ranged from 8.8% to 11.4%. Codfish frames had the highest lipid content in both pupae (11.4%) and adults (13%). The most abundant fatty acid in Fucus sp. – fed pupae and adult flies was oleic acid (18:1 n-9), while palmitoleic acid (16:1 n-7) dominated in other treatments. It is worth highlighting that docosahexaenoic acid (22:6 n-3) was reported for the first time in a seaweed fly, namely when supplied with fish processing waste. These findings suggest that Fucellia maritima may be a promising complementary ingredient for formulating marine aquafeeds.

In vitro versus cryo-induced capacitation of bovine spermatozoa, part 3: Compositional and molecular changes to the plasma membrane

The aim of this study was to assess the level of membrane cryodamage through the levels of selected capacitation and apoptosis-associated proteins, together with compositional membrane changes in capacitated (CAP), cryopreserved (CRYO) and non-capacitated bovine spermatozoa (CRTL). Sperm kinetic parameters were analyzed by the computer assisted sperm analysis (CASA) while the capacitation patterns were examined with the chlortetracycline (CTC) assay. In the case of DNA integrity, sperm chromatin structure assay and aniline blue staining were used. For the quantification of fatty acid content gas chromatography was performed. Using Western blotting the expression of capacitation (protein kinase C – PKC; phospholipases A2 and Cζ – PLA2, PLCζ; soluble adenylyl cyclase 10 – sAC10) and apoptosis-associated (apoptosis regulator Bax; B-cell lymphoma 2 – Bcl-2; caspase 3) proteins were evaluated. Data indicate a significant decline (p < 0.0001) of sperm kinetic parameters and higher occurrence (p < 0.0001) of DNA fragmentation in the CRYO group. CTC assay revealed a significant increase of acrosome-reacted spermatozoa in the CRYO group when compared to others. Compositional changes in the sperm membrane were visible as a notable decline of docosahexaenoic acid (p < 0.0001) associated with a significant decrease of membrane cholesterol (p < 0.05) and proteins (p < 0.0001) in the CRYO group while the amount of palmitic, stearic, oleic, and linoleic acid increased (p < 0.0001) significantly. Protein expression of all capacitation-associated proteins (PKC, PLA2, PLCζ, sAC10) was significantly down-regulated (p < 0.001; p < 0.0001) in the CRYO group. Relative quantification of apoptosis-associated proteins revealed increased Bax and decreased Bcl-2 levels in the CRYO group, except for caspase-3, which remained without significant changes.

Randomized dose-response trial of n-3 fatty acids in hormone receptor negative breast cancer survivors- impact on breast adipose oxylipin and DNA methylation patterns.

Increasing evidence suggests the unique susceptibility of estrogen receptor and progesterone receptor negative (ERPR-) breast cancer to dietary fat amount and type. Dietary n-3 polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), may modulate breast adipose fatty acid profiles and downstream bioactive metabolites to counteract pro-inflammatory, pro-carcinogenic signaling in the mammary microenvironment. To determine effects of ~1 to 5 g/d EPA+DHA over 12 months on breast adipose fatty acid and oxylipin profiles in women with ERPR(-) breast cancer, a high-risk molecular subtype. We conducted a 12-month randomized controlled, double-blind clinical trial of ~5g/d vs ~1g/d DHA+EPA supplementation in women within 5 years of completing standard therapy for ERPR(-) breast cancer Stages 0-III. Blood and breast adipose tissue specimens were collected every 3 months for biomarker analyses including fatty acids by gas chromatography, oxylipins by LC-MS/MS, and DNA methylation by reduced-representation bisulfite sequencing (RRBS). A total of 51 participants completed the 12-month intervention. Study treatments were generally well-tolerated. While both doses increased n-3 PUFAs from baseline in breast adipose, erythrocytes, and plasma, the 5g/d supplement was more potent (n =51, p <0.001). The 5g/d dose also reduced plasma triglycerides from baseline (p =0.008). Breast adipose oxylipins at 0, 6, and 12 months showed dose-dependent increases in unesterified and esterified DHA and EPA metabolites (n =28). Distinct DNA methylation patterns in adipose tissue after 12 months were identified, with effects unique to the 5g/d dose group (n =17). Over the course of 1 year, EPA+DHA dose-dependently increased concentrations of these fatty acids and their derivative oxylipin metabolites, producing differential DNA methylation profiles of gene promoters involved in metabolism-related pathways critical to ERPR(-) breast cancer development and progression. These data provide evidence of both metabolic and epigenetic effects of n-3 PUFAs in breast adipose tissue, elucidating novel mechanisms of action for high-dose EPA+DHA-mediated prevention of ERPR(-) breast cancer.

IPSC-Derived LCHADD Retinal Pigment Epithelial Cells Are Susceptible to Lipid Peroxidation and Rescued by Transfection of a Wildtype AAV-HADHA Vector.

Progressive choroid and retinal pigment epithelial (RPE) degeneration causing vision loss is a unique characteristic of long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD), a fatty acid oxidation disorder caused by a common c.1528G>C pathogenic variant in HADHA, the α subunit of the mitochondrial trifunctional protein (TFP). We established and characterized an induced pluripotent stem cell (iPSC)-derived RPE cell model from cultured skin fibroblasts of patients with LCHADD and tested whether addition of wildtype (WT) HAHDA could rescue the phenotypes identified in LCHADD-RPE. We constructed an rAAV expression vector containing 3' 3xFLAG-tagged human HADHA cDNA under the transcriptional control of the cytomegalovirus (CMV) enhancer-chicken beta actin (CAG) promoter (CAG-HADHA-3XFLAG). LCHADD-RPE were cultured, matured, and transduced with either AAV-GFP (control) or AAV-HADHA-3XFLAG. LCHADD-RPE express TFP subunits and accumulate 3-hydroxy-acylcarnitines, cannot oxidize palmitate, and release fewer ketones than WT-RPE. When LCHADD-RPE are exposed to docosahexaenoic acid (DHA), they have increased oxidative stress, lipid peroxidation, decreased viability, and are rescued by antioxidant agents potentially explaining the pathologic mechanism of RPE loss in LCHADD. Transduced LCHADD-RPE expressing a WT copy of TFPα incorporated TFPα-FLAG into the TFP complex in the mitochondria and accumulated significantly less 3-hydroxy-acylcarnitines, released more ketones in response to palmitate, and were more resistant to oxidative stress following DHA exposure than control. iPSC-derived LCHADD-RPE are susceptible to lipid peroxidation mediated cell death and are rescued by exogenous HADHA delivered with rAAV. These results are promising for AAV-HADHA gene addition therapy as a possible treatment for chorioretinopathy in patients with LCHADD.

Blue Food Consumption and Its Relation to Nutrient Intake among Koreans.

(1) Background: "Blue food" is a recently coined term referring to seafood, emphasizing health benefits and sustainability. This study compares nutrient intake levels between Koreans who consume fish and shellfish and those who do not. (2) Methods: Data from the eighth Korea National Health and Nutrition Examination Survey (2019-2020) were used. A total of 9442 individuals were analyzed (≥1 year old). A complex sample design was applied. (3) Results: Younger individuals aged 9 to 29 consumed less fish and shellfish, while those with higher education and income levels consumed more. Compared with the non-consumption group, individuals in the fish and shellfish consumption group exhibited a higher nutrient density in their diets, excluding total fat, saturated fatty acids, monounsaturated fatty acids, and riboflavin (p < 0.01). They also had a higher proportion of nutrient intakes relative to the Recommended Nutrient Intake level for all nutrients than the non-consumption group (p < 0.001), particularly in eicosapentaenoic acid and docosahexaenoic acid intakes. Conversely, the non-consumption group had a higher proportion of nutrient intakes below the Estimated Average Requirement compared with the consumption group. (p < 0.001). (4) Conclusions: Individuals consuming blue food exhibited higher levels of nutrient intake. Developing strategies to promote the consumption of blue food, considering factors such as age, education, and income, is essential.