Plant-based stearidonic acid as sustainable source of omega-3 fatty acid with functional outcomes on human health

Co-applied magnesium nanoparticles and biochar modulate salinity stress via regulating yield, biochemical attribute, and fatty acid profile of Physalis alkekengi L

While previous studies have addressed the desirable effects of biochar (BC) or magnesium nanoparticles (Mg NPs) on salinity stress individually, there is a research gap regarding their simultaneous application. Additionally, the specific mechanisms underlying the effects of BC and Mg NPs on salinity in Physalis alkekengi L. remain unclear. This study aimed to investigate the synergistic effects of BC and Mg NPs on P. alkekengi L. under salinity stress conditions. A pot experiment was conducted with salinity at 100 and 200 mM sodium chloride (NaCl), as well as soil applied BC (4% v/v) and foliar applied Mg NPs (500 mg L-1) on physiological and biochemical properties of P. alkekengi L. The results represented that salinity, particularly 200 mM NaCl, significantly reduced plant yield (58%) and total chlorophyll (Chl, 36%), but increased superoxide dismutase (SOD, 82%) and catalase (CAT, 159%) activity relative to non-saline conditions. However, the co-application of BC and Mg NPs mitigated these negative effects and improved fruit yield, Chl, anthocyanin, and ascorbic acid. It also decreased the activity of antioxidant enzymes. Salinity also altered the fatty acid composition, increasing saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs), while decreasing monounsaturated fatty acids (MUFAs). The heat map analysis showed that fruit yield, anthocyanin, Chl, and CAT were sensitive to salinity. The findings can provide insights into the possibility of these amendments as sustainable strategies to mitigate salt stress and enhance plant productivity in affected areas.

Proteomic and Metabolomic Signatures of Diet Quality in Young Adults

The assessment of "omics" signatures may contribute to personalized medicine and precision nutrition. However, the existing literature is still limited in the homogeneity of participants' characteristics and in limited assessments of integrated omics layers. Our objective was to use post-prandial metabolomics and fasting proteomics to identify biological pathways and functions associated with diet quality in a population of primarily Hispanic young adults. We conducted protein and metabolite-wide association studies and functional pathway analyses to assess the relationships between a priori diet indices, Healthy Eating Index-2015 (HEI) and Dietary Approaches to Stop Hypertension (DASH) diets, and proteins (n = 346) and untargeted metabolites (n = 23,173), using data from the MetaAIR study (n = 154, 61% Hispanic). Analyses were performed for each diet quality index separately, adjusting for demographics and BMI. Five proteins (ACY1, ADH4, AGXT, GSTA1, F7) and six metabolites (undecylenic acid, betaine, hyodeoxycholic acid, stearidonic acid, iprovalicarb, pyracarbolid) were associated with both diets (p < 0.05), though none were significant after adjustment for multiple comparisons. Overlapping proteins are involved in lipid and amino acid metabolism and in hemostasis, while overlapping metabolites include amino acid derivatives, bile acids, fatty acids, and pesticides. Enriched biological pathways were involved in macronutrient metabolism, immune function, and oxidative stress. These findings in young Hispanic adults contribute to efforts to develop precision nutrition and medicine for diverse populations.

Integrated metabolomics and transcriptomics revealed the anti-constipation mechanisms of xylooligosaccharides from corn cobs

Xylooligosaccharides (XOSs) have recently garnered interest for their potential as an anti-constipation agent. In this study, we investigated the effects of XOSs derived from corn cobs on constipation in mice through a comprehensive analysis of both the metabolome and transcriptome. Our multi-omics approach revealed that XOSs primarily modulated butanoate metabolism and steroid hormone biosynthesis pathways, as well as key signaling pathways such as PPAR and NF-kappa B. Notably, we observed a decrease in inflammatory biomarker expression and an elevation of butyric acid metabolite levels with XOSs treatment. A deeper analysis of gene expression and metabolite alterations highlighted significant changes in genes encoding critical enzymes and metabolites involved in these pathways. Overall, these findings underscore the considerable potential of XOSs derived from corn cobs as a dietary supplement for effectively alleviating constipation.

Human gut microbiota and their production of endocannabinoid-like mediators are directly affected by a dietary oil

Dietary omega-3 polyunsaturated fatty acids (n-3 PUFAs) and the gut microbiome affect each other. We investigated the impact of supplementation with Buglossoides arvensis oil (BO), rich in stearidonic acid (SDA), on the human gut microbiome. Employing the Mucosal Simulator of the Human Intestinal Microbial Ecosystem (M-SHIME), we simulated the ileal and ascending colon microbiomes of four donors. Our results reveal two distinct microbiota clusters influenced by BO, exhibiting shared and contrasting shifts. Notably, Bacteroides and Clostridia abundance underwent similar changes in both clusters, accompanied by increased propionate production in the colon. However, in the ileum, cluster 2 displayed a higher metabolic activity in terms of BO-induced propionate levels. Accordingly, a triad of bacterial members involved in propionate production through the succinate pathway, namely Bacteroides, Parabacteroides, and Phascolarctobacterium, was identified particularly in this cluster, which also showed a surge of second-generation probiotics, such as Akkermansia, in the colon. Finally, we describe for the first time the capability of gut bacteria to produce N-acyl-ethanolamines, and particularly the SDA-derived N-stearidonoyl-ethanolamine, following BO supplementation, which also stimulated the production of another bioactive endocannabinoid-like molecule, commendamide, in both cases with variations across individuals. Spearman correlations enabled the identification of bacterial genera potentially involved in endocannabinoid-like molecule production, such as, in agreement with previous reports, Bacteroides in the case of commendamide. This study suggests that the potential health benefits on the human microbiome of certain dietary oils may be amenable to stratified nutrition strategies and extend beyond n-3 PUFAs to include microbiota-derived endocannabinoid-like mediators.

Bioactive fatty acids from non-conventional lipid sources and their potential application in functional food development

There is growing evidence that bioactive fatty acids (BFAs), including eicosapentaenoic acid (EPA; 20:5-3), docosahexaenoic acid (DHA; 22:6-3), and conjugated fatty acids offer multiple biological benefits and constitute ingredients in functional food development. Despite their potential, novel and alternative/nonconventional sources with unique bioactive properties to meet growing demand remain largely unexplored, poorly characterized, and their effects are not well understood. We systematically reviewed the literature to identify studies on alternative sources of BFAs, their functions, extraction, and application in the food and nutraceutical industry. Twenty studies delved into alternate sources such as plants, bacteria, and algae. Six studies found EPA and DHA as the dominant FA in algal sources, while ten studies reported several BFAs from plant sources. Five studies assessed the health benefits of docosapentaenoic acid (DPA), arachidonic acid (ARA), EPA, γ-linolenic acid (GLA), and linoleic acid (LA). Eleven studies compared the quality of oil recovered by green solvents, pressurized liquid, supercritical fluid, and assisted extraction methods. Three studies assessed the effects of assisted extraction methods and reported that these approaches improved oil yield and quality, but the findings may have limited applicability to other lipid sources. The quality of nonconventional lipids largely depends on extraction techniques. Four studies suggested methods like 1D and 2D NMR spectroscopy, LC-MS/MS; however, their analytical differences make accurate comparison inadequate. Five studies found that the incorporation of algal and seafood biolipids during product development increased EHA and DHA contents.

A comparison of Echium, fish, palm, soya, and linseed oil supplementation on pork quality

OBJECTIVE

Long chain n-3 polyunsaturated fatty acids (PUFA) exert positive effects on human health. The long chain n-3 PUFA of pork can be increased by adding fish oil to the diet. Due to the cost and availability of fish oil an alternative source must be found.

METHODS

This study evaluated the effect of five dietary oils on meat quality, fatty acid composition and lipid stability. The five diets contained 1% palm oil (Control), 1% soya oil, 1% linseed oil, 1% fish oil, and 1% Echium oil, respectively. The trial consisted of 60 gilts, randomly allocated to five groups.

RESULTS

All color parameters, extractable fat content, fat free dry matter, and moisture content of the m. longissimus muscle were unaffected by dietary treatment. Consumers and a trained sensory panel could not detect a difference between the control samples and the Echium oil sample during sensory analysis. Samples containing higher levels of PUFA (soya, linseed, fish, and Echium oil) had higher levels of primary and secondary lipid oxidation products after refrigerated and frozen storage. However, these values were still well below the threshold value where off flavors can be detected. The Echium oil treatment had significantly higher levels of long chain PUFA than the linseed oil treatment, but it was still significantly lower than that of the fish oil treatment.

CONCLUSION

Echium oil supplementation did not increase the levels of n-3 to the same extent as fish oil did. The result did however suggest that Echium oil can be used in pig diets to improve muscle long chain n-3 fatty acid content without any adverse effects on meat quality when compared to linseed, soya, and palm oil.

Bioprocess engineering to produce essential polyunsaturated fatty acids from Thraustochytrium sp

In recent studies, thraustochytridhas emerged as a sustainable substitute to fish oil or polyunsaturated fatty acid(PUFA) sources: docosapentaenoic acid (DPA) eicosapentaenoic acid(EPA), anddocosahexaenoic acid(DHA). Due to growing health concerns, there is increasing demand for commercial application of PUFA to several diseases, aquaculture feeds, and dietary products. Thraustochytrium sp. found a sustainable source for considerable PUFA and SFA production and is expected to meet omega PUFA demand globally. This study aims to increase PUFA yield by glucose carbon with an appropriate nitrogen ratio (10:1). The maximum biomass and lipid obtained from 40 g/L glucose, with 7.47±0.3 g/L and 4.63 g/L (60.84±1.4%) yields, respectively. However, maximum relative lipid, DHA and DPA yields were from 30 g/L glucose i.e, 67.6±1.9 % and 963.58±24 and 693.10±24 mg/L respectively with complete glucose assimilation. Thus, this could be a potential source of commercial DPA and DHA producers under the biorefinery scheme.

Differential Lipid Accumulation on HepG2 Cells Triggered by Palmitic and Linoleic Fatty Acids Exposure

Lipid metabolism pathways such as β-oxidation, lipolysis and, lipogenesis, are mainly associated with normal liver function. However, steatosis is a growing pathology caused by the accumulation of lipids in hepatic cells due to increased lipogenesis, dysregulated lipid metabolism, and/or reduced lipolysis. Accordingly, this investigation hypothesizes a selective in vitro accumulation of palmitic and linoleic fatty acids on hepatocytes. After assessing the metabolic inhibition, apoptotic effect, and reactive oxygen species (ROS) generation by linoleic (LA) and palmitic (PA) fatty acids, HepG2 cells were exposed to different ratios of LA and PA to study the lipid accumulation using the lipophilic dye Oil Red O. Lipidomic studies were also carried out after lipid isolation. Results revealed that LA was highly accumulated and induced ROS production when compared to PA. Lipid profile modifications were observed after LA:PA 1:1 (v/v) exposure, which led to a four-fold increase in triglycerides (TGs) (mainly in linoleic acid-containing species), as well as a increase in cholesterol and polyunsaturated fatty acids (PUFA) content when compared to the control cells. The present work highlights the importance of balancing both PA and LA fatty acids concentrations in HepG2 cells to maintain normal levels of free fatty acids (FFAs), cholesterol, and TGs and to minimize some of the observed in vitro effects (i.e., apoptosis, ROS generation and lipid accumulation) caused by these fatty acids.

Promising Sources of Plant-Derived Polyunsaturated Fatty Acids: A Narrative Review

(1) Background: Polyunsaturated fatty acids (PUFAs) are known for their ability to protect against numerous metabolic disorders. The consumption of oily fish is the main source of PUFAs in human nutrition and is commonly used for supplement production. However, seafood is an overexploited source that cannot be guaranteed to cover the global demands. Furthermore, it is not consumed by everyone for ecological, economic, ethical, geographical and taste reasons. The growing demand for natural dietary sources of PUFAs suggests that current nutritional sources are insufficient to meet global needs, and less and less will be. Therefore, it is crucial to find sustainable sources that are acceptable to all, meeting the world population's needs. (2) Scope: This review aims to evaluate the recent evidence about alternative plant sources of essential fatty acids, focusing on long-chain omega-3 (n-3) PUFAs. (3) Method: A structured search was performed on the PubMed search engine to select available human data from interventional studies using omega-3 fatty acids of non-animal origin. (4) Results: Several promising sources have emerged from the literature, such as algae, microorganisms, plants rich in stearidonic acid and GM plants. However, the costs, acceptance and adequate formulation deserve further investigation.

Neuroprotective Effect of Stearidonic Acid on Amyloid β-Induced Neurotoxicity in Rat Hippocampal Cells

Dietary intake of omega-3 fatty acids found in fish has been reported to reduce the risk of Alzheimer's Disease (AD). Stearidonic acid (SDA), a plant-based omega-3 fatty acid, has been targeted as a potential surrogate for fish-based fatty acids. However, its role in neuronal degeneration is unknown. This study was designed to evaluate effects of SDA on Amyloid-β(A-β)-induced neurotoxicity in rat hippocampal cells. Results showed that SDA effectively converted to eicosapentaenoic acid (EPA) in hippocampal cells. Aβ-induced apoptosis in H19-7 cells was protected by SDA pretreatment as evidenced by its regulation on the expression of relevant pro- and anti-apoptotic genes, as well as the inhibition on caspase activation. SDA also protected H19-7 cells from Aβ-induced oxidative stress by regulating the expression of relevant pro- and anti-oxidative genes, as well as the improvement in activity of catalase. As for Aβ/LPS-induced neuronal inflammation, SDA pretreatment reduced the release of IL-1β and TNFα. Further, we found that the anti-Aβ effect of SDA involves its inhibition on the expression of amyloid precursor protein and the regulation on MAPK signaling. These results demonstrated that SDAs have neuroprotective effect in Aβ-induced H19-7 hippocampal cells. This beneficial effect of SDA was attributed to its antiapoptotic, antioxidant, and anti-inflammatory properties.

Solid-state fermentation produces greater stearidonic acid levels in genetically engineered Mucor circinelloides

Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are important dietary components due to their health benefits and preventative role in cardiovascular disease. Fish-based and plant seed oils are rich in stearidonic acid (SDA; 18:4 n-3) which are readily metabolized into ω-3 PUFAs such as eicosapentaenoic acid. However, these natural sources of SDA are generally low yielding and are unlikely to meet global demands, so new sustainable microbial fermentative sources of SDA need to be identified. Expression of delta15-desaturase in the oleaginous filamentous fungus Mucor circinelloides (McD15D) has been used to construct a recombinant SDA-producing McD15D strain that produces 5.0% SDA levels using submerged fermentation conditions. Switching to solid-state fermentation conditions in the same medium with submerged fermentation resulted in this engineered strain producing significantly higher amounts of SDA. A Box-Behnken design (BBD) of response surface methodology (RSM) approach has been used to identify optimal glucose and ammonium tartrate concentrations and temperature levels to maximize SDA production. The use of these optimal solid-state fermentation conditions resulted in the spores and mycelium of the recombinant McD15D producing 19.5% (0.64 mg g^-1 ) and 12.2% (1.52 mg g^-1 ) SDA content respectively, which represents an overall increase in SDA yield of 188.0% when compared to SDA yields produced using submerged fermentation conditions.

Improving the content of high value compounds in Nordic Desmodesmus microalgal strains

Nordic Desmodesmus microalgal strains (2-6) and (RUC-2) were exposed to abiotic stress (light and salt) to enhance lipids and carotenoids. The biomass output of both strains increased by more than 50% during light stress of 800 μmol m^-2 s^-1 compared to control light. The biomass of Desmodesmus sp. (2-6) contained most lipids (15% of dry weight) and total carotenoids (16.6 mg g^-1) when grown at moderate light stress (400 μmol m^-2 s^-1), which further could be enhanced up to 2.5-fold by salinity stress. Desmodesmus sp. (RUC-2) exhibited maximal lipid (26.5%) and carotenoid (43.8 mg L^-1) content at light intensities of 400 and 100 μmol m^-2 s^-1, respectively. Salinity stress stimulated lipid accumulation by 39%. Nordic Desmodesmus strains therefore are not only able to tolerate stress conditions, but their biomass considerably improves under stress. These strains have high potential to be used in algal bio-factories on low-cost medium like Baltic seawater.

Effects of Dietary α-Linolenic Acid Treatment and the Efficiency of Its Conversion to Eicosapentaenoic and Docosahexaenoic Acids in Obesity and Related Diseases

The essential fatty acid alpha-linolenic acid (ALA) is present in high amounts in oils such as flaxseed, soy, hemp, rapeseed, chia, and perilla, while stearidonic acid is abundant in echium oil. ALA is metabolized to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by desaturases and elongases in humans. The conversion of ALA to EPA and DHA is limited, and these long-chain n−3 polyunsaturated fatty acids (PUFAs) are mainly provided from dietary sources (fish and seafood). This review provides an overview of studies that explored the effects of dietary supplementation with ALA in obesity and related diseases. The obesity-associated changes of desaturase and elongase activities are summarized, as they could influence the metabolic conversion of ALA. Generally, supplementation with ALA or ALA-rich oils leads to an increase in EPA levels and has no effect on DHA or omega-3 index. According to the literature data, stearidonic acid could enhance conversion of ALA to long-chain n−3 PUFA in obesity. Recent studies confirm that EPA and DHA intake should be considered as a primary dietary treatment strategy for improving the omega-3 index in obesity and related diseases.

Recent advances in the development of bitter gourd seed oil: from chemical composition to potential applications

Non-conventional seed oils are being considered novelty foods due to the unique properties of their chemical constituents. Numerous such seed oils serve as nutritional and functional supplements, making them a point of interest for scholars. Bitter gourd (Momordica charantia L.) seed oil (BGSO) has been widely used in folk medicine worldwide for the treatment of different pathologies, such as diabetes, cancer, and several inflammatory diseases. Therefore, its nutritional and medicinal value has been extensively studied. Considering the potential use of BGSO, it is imperative to have a comprehensive understanding of this product to develop and use its biologically active ingredients in innovative food and pharmaceutical products. An extensive understanding of BGSO would also help improve the economic feasibility of the bitter gourd seed processing industry and help prevent environmental pollution associated with the raw waste produced during the processing of bitter gourd seeds. This review addresses the potential uses of BGSO in terms of food and pharmaceuticals industry perspectives and comprehensively summarizes the oil extraction process, chemical composition, biological activity, and the application prospects of BGSO in clinical medicine.

Synechococcus elongatus PCC 7942 as a Platform for Bioproduction of Omega-3 Fatty Acids

Alpha-linolenic acid and stearidonic acid are precursors of omega-3 polyunsaturated fatty acids, essential nutrients in the human diet. The ability of cyanobacteria to directly convert atmospheric carbon dioxide into bio-based compounds makes them promising microbial chassis to sustainably produce omega-3 fatty acids. However, their potential in this area remains unexploited, mainly due to important gaps in our knowledge of fatty acid synthesis pathways. To gain insight into the cyanobacterial fatty acid biosynthesis pathways, we analyzed two enzymes involved in the elongation cycle, FabG and FabZ, in Synechococcus elongatus PCC 7942. Overexpression of these two enzymes led to an increase in C18 fatty acids, key intermediates in omega-3 fatty acid production. Nevertheless, coexpression of these enzymes with desaturases DesA and DesB from Synechococcus sp. PCC 7002 did not improve alpha-linolenic acid production, possibly due to their limited role in fatty acid synthesis. In any case, efficient production of stearidonic acid was not achieved by cloning DesD from Synechocystis sp. PCC 6803 in combination with the aforementioned DesA and DesB, reaching maximum production at 48 h post induction. According to current knowledge, this is the first report demonstrating that S. elongatus PCC 7942 can be used as an autotrophic chassis to produce stearidonic acid.

Fatty acid profile, sterols, and squalene content comparison between two conventional (olive oil and linseed oil) and three non‐conventional vegetable oils (echium oil, hempseed oil, and moringa oil)

Abstract

New sources of bioactive compounds are constantly explored for reformulating healthier foods. This work aimed to explore and characterize the fatty acid profile and sterol content of three non‐conventional oils used in functional food products (hempseed oil, moringa oil, and echium oil) and to compare them with two conventional ones (extra virgin olive oil [EVOO] and linseed oil). Oxidative stability was assessed by determining their acidity value and peroxide content. All oils showed adequate values for acidity and oxidation status. Echium and hempseed oils showed a high content of polyunsaturated fatty acids (>70%), especially omega‐3 fatty acids, while moringa oil was rich in oleic acid. Echium oil, hempseed oil, and moringa oil presented higher sterol content than EVOO, but lower than that of linseed oil. Sitosterol was the most abundant sterol in all samples (97.88–275.36 mg/100 g oil), except in echium oil, where campesterol (170.62 mg/100 g oil) was the major sterol. Squalene was only found in significant amounts in EVOO. In conclusion, non‐conventional oils seem to be interesting sources of bioactive compounds and have great potential for the food industry.

Practical Application

Non‐conventional vegetable oils can be used as alternative sources of lipids in a variety of food products. Additionally, these oils have great potential to be included in the formulation of functional ingredients for the delivery of omega‐3 fatty acids, antioxidants, fiber, among others.

Profiling of Lipids, Nutraceuticals, and Bioactive Compounds Extracted from an Oilseed Rich in PUFA

Polyunsaturated fatty acid (PUFA) rich vegetable oils are nutritionally and economically important agriculture based commodities. The lipid profile, nutraceutical content, and antioxidant activity of Indian chia seed oil (CSO) were analysed and compared with PUFA rich vegetable oils. The total oil content was 28% (w/w) with α-linolenic acid (ALA; 65%) as the predominant fatty acid and a n-3/n-6 ratio of 3.5. The tocopherol content was 144 mg/kg of oil, with γ + β being the most abundant. The squalene content was 178.47 mg/100 g of oil, and the total phenolic content was 0.014 mg GAE/g of oil. The identity of major polyphenols in the methanolic extract of CSO were established by LC-HRMS. FTIR spectra of CSO exhibited characteristic features that were identical to other PUFA rich oils. Results demonstrate that the Indian CSO is an excellent source of essential fatty acids and key nutraceuticals.

α-Linolenic Acid and Risk of Heart Failure: A Meta-Analysis

Background: The α-linolenic acid is a plant origin n-3 fatty acid that may reduce the risk of cardiovascular disease. However, the effect of α-linolenic acid (ALA) on the risk of heart failure (HF) remains unclear. In this meta-analysis, we aimed to determine the role of ALA in the risk of incident HF.

Methods: Electronic databases were searched for studies up to August 10, 2021. Studies were included for meta-analysis if the adjusted risk of HF in different dietary intake or circulating levels of ALA was reported. We used the random-effects model to calculate the estimated hazard ratios (HRs) and 95% CI for higher ALA.

Results: A total of 6 studies (7 cohorts) comprising 135,270 participants were included for meta-analysis. After a median follow-up duration of 10 years, 5,905 cases of HF were recorded. No significant heterogeneity was observed among all the included studies. Random-effects model analyses showed that there was no significant association between ALA and the risk of incident HF, either assessed as quintiles (highest quintile vs. lowest quintile: HR = 0.95, 95% CI = 0.86–1.06) or per 1 SD increment (HR = 0.99, 95% CI = 0.95–1.01). Furthermore, we did not observe any association between ALA and the risk of HF in subgroup analyses performed according to age, sex, follow-up duration, and measuring method of ALA.

Conclusions: We found no association between ALA and the risk of incident HF, suggesting that ALA might not be effective in the prevention of HF.

(Wh)olistic (E)ndocannabinoidome-Microbiome-Axis Modulation through (N)utrition (WHEN) to Curb Obesity and Related Disorders

The discovery of the endocannabinoidome (eCBome) is evolving gradually with yet to be elucidated functional lipid mediators and receptors. The diet modulates these bioactive lipids and the gut microbiome, both working in an entwined alliance. Mounting evidence suggests that, in different ways and with a certain specialisation, lipid signalling mediators such as N-acylethanolamines (NAEs), 2-monoacylglycerols (2-MAGs), and N-acyl-amino acids (NAAs), along with endocannabinoids (eCBs), can modulate physiological mechanisms underpinning appetite, food intake, macronutrient metabolism, pain sensation, blood pressure, mood, cognition, and immunity. This knowledge has been primarily utilised in pharmacology and medicine to develop many drugs targeting the fine and specific molecular pathways orchestrating eCB and eCBome activity. Conversely, the contribution of dietary NAEs, 2-MAGs and eCBs to the biological functions of these molecules has been little studied. In this review, we discuss the importance of (Wh) olistic (E)ndocannabinoidome-Microbiome-Axis Modulation through (N) utrition (WHEN), in the management of obesity and related disorders.

Consensus mutagenesis and computational simulation provide insight into the desaturation catalytic mechanism for delta 6 fatty acid desaturase

Fatty acid desaturase (FADS) generates double bond at a certain position of the corresponding polyunsaturated fatty acids (PUFAs) with high selectivity, the enzyme activity and PUFAs products of which are essential to biological systems and are associated with a variety of physiological diseases. Little is known about the structure of FADSs and their amino acid residues related to catalytic activities. Identifying key residues of Micromonas pusilla delta 6 desaturase (MpFADS6) provides a point of departure for a better understanding of desaturation. In this study, conserved amino acids were anchored through gene consensus analysis, thereby generating corresponding variants by site-directed mutagenesis. To achieve stable and high-efficiency expression of MpFADS6 and its variants in Saccharomyces cerevisiae, the key points of induced expression were optimized. The contribution of conserved residues to the function of enzyme was determined by analyzing enzyme activity of the variants. Molecular modeling indicated that these residues are essential to catalytic activities, or substrate binding. Mutants MpFADS6_[Q409R] and MpFADS6_[M242P] abolished desaturation, while MpFADS6_[F419V] and MpFADS6_[A374Q] significantly reduced catalytic activities. Given that certain residues have been identified to have a significant impact on MpFADS6 activities, it is put forward that histidine-conserved region III of FADS6 is related to electronic transfer during desaturation, while histidine-conserved regions I and II are related to desaturation. These findings provide new insights and methods to determine the structure, mechanism and directed transformation of membrane-bound desaturases.

Chemical characterization of Echium plantagineum seed oil obtained by three methods of extraction

Echium seed oil has been considered an important alternative source of omega 3 fatty acids (n-3 FA) for human consumption. Considering the oxidative instability of n-3 FA richer oils, the objective of this study was to determine the chemical and sensory parameters of the oil obtained from Echium plantagineum seeds obtained by three extraction methods (hydraulic press: HYD; continuous screw press: PRESS; and solvent technique: SOLV). Stearidonic acid (C18:4, n3), the most important n-3 FA present in the oil, changed from 12.5% to 12.7%. Regarding the minor compounds, PRESS sample showed the highest concentration of gamma-tocopherol (782.24 mg/kg oil), while SOLV samples presented the highest amount of β-sitosterol (73.46 mg/100 g) with no difference of campesterol concentration (159.56 mg/100 g) among the samples. Higher values of total phenolics (19.65 mg GAE/kg oil) and β-carotene (34.83 mg/kg oil) were also found in the SOLV samples, suggesting the influence of hexane in the extraction of these bioactive compounds. High resolution mass spectrometry identified caffeic acid and its derivatives as the main phenolic compounds present in the echium oil. PRESS sample showed the best oxidative stability as measured by PV (0.61 mmol/kg oil) and malondialdehyde (173.13 µmol), probably due to faster time of processing compared to HYD and SOLV samples. Our data showed that the extraction method changed the chemical composition of the minor compounds in the echium oil, but these alterations did not reduce its nutritional quality or sensory acceptability. PRACTICAL APPLICATION: Echium oil represents a great potential source of omega 3 fatty acids, but there is not enough information about its oxidative stability and chemical composition, especially toward minor compounds. Our study characterizes echium oil composition obtained from three extraction methods, contributing to amplify the technical information about this important alternative oil for human consumption.

Omega-3 Polyunsaturated Fatty Acids (PUFAs): Emerging Plant and Microbial Sources, Oxidative Stability, Bioavailability, and Health Benefits-A Review

The omega−3 (n−3) polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic (DHA) acid are well known to protect against numerous metabolic disorders. In view of the alarming increase in the incidence of chronic diseases, consumer interest and demand are rapidly increasing for natural dietary sources of n−3 PUFAs. Among the plant sources, seed oils from chia (Salvia hispanica), flax (Linum usitatissimum), and garden cress (Lepidium sativum) are now widely considered to increase α-linolenic acid (ALA) in the diet. Moreover, seed oil of Echium plantagineum, Buglossoides arvensis, and Ribes sp. are widely explored as a source of stearidonic acid (SDA), a more effective source than is ALA for increasing the EPA and DHA status in the body. Further, the oil from microalgae and thraustochytrids can also directly supply EPA and DHA. Thus, these microbial sources are currently used for the commercial production of vegan EPA and DHA. Considering the nutritional and commercial importance of n−3 PUFAs, this review critically discusses the nutritional aspects of commercially exploited sources of n−3 PUFAs from plants, microalgae, macroalgae, and thraustochytrids. Moreover, we discuss issues related to oxidative stability and bioavailability of n−3 PUFAs and future prospects in these areas.

Essential Fatty Acids as Biomedicines in Cardiac Health

The destructive impact of cardiovascular diseases on health, including heart failure, peripheral artery disease, atherosclerosis, stroke, and other cardiac pathological conditions, positions these health conditions as leading causes of increased global mortality rates, thereby impacting the human quality of life. The considerable changes in modern lifestyles, including the increase in food intake and the change in eating habits, will unavoidably lead to an unbalanced consumption of essential fatty acids, with a direct effect on cardiovascular health problems. In the last decade, essential fatty acids have become the main focus of scientific research in medical fields aiming to establish their impact for preventing cardiovascular diseases and the associated risk factors. Specifically, polyunsaturated fatty acids (PUFA), such as omega 3 fatty acids, and monounsaturated fatty acids from various sources are mentioned in the literature as having a cardio-protective role, due to various biological mechanisms that are still to be clarified. This review aims to describe the major biological mechanisms of how diets rich in essential fatty acids, or simply essential fatty acid administration, could have anti-inflammatory, vasodilatory, anti-arrhythmic, antithrombotic, antioxidant, and anti-atherogenic effects. This review describes findings originating from clinical studies in which dietary sources of FAs were tested for their role in mitigating the impact of heart disorders in human health.

Proteomics and lipidomics reveal the protective mechanism of dietary n-3 PUFA supplementation for photoaging

Chronic ultraviolet radiation exposure could induce photoaging, and even carcinogenesis. Dietary omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation has proved to alleviate photoaging and cutaneous carcinoma. Although the exact mechanism remains poorly elucidated, accumulated evidence suggests that the alleviation effect of n-3 PUFA for photoaging is a multifactorial procession characterized by different pathways. Here, we performed a whole-genome proteomics and lipidomics analyses using a self-constructed photoaging mouse model with n-3 PUFA or n-6 PUFA supplementation. Significant alleviation of photoaging was observed, and a total of 88 differentially expressed proteins and 152 differentially expressed lipids were identified in mice with n-3 PUFA supplementation. We found that n-3 PUFA may alleviate photoaging by upregulating Hmmr (hyaluronic acid receptor) expression, which can decrease Mmp9 expression, reducing collagen degradation. As most proteins were associated with lipogenesis and lipid metabolism, we further analyzed the lipidomics data, finding that most triglycerides (93%) showed a significant increase in the n-3 PUFA supplementation group. Our proteomics and lipidomics results indicate that the protective mechanism of n-3 PUFA for photoaging is complicated. Furthermore, the effect of elevated triglycerides by n-3 PUFA supplementation in counteracting skin photoaging cannot be ignored, which will become a new prime target in anti-photoaging.

Serum ω-6/ω-3 polyunsaturated fatty acids ratio and diabetic retinopathy: A propensity score matching based case-control study in China

BACKGROUND

Optimal ω-6/ω-3 polyunsaturated fatty acids ratio (PUFAR) is reported to exert protective effects against chronic diseases. However, data on PUFAR and diabetic retinopathy (DR) remains scarce. We aimed to thoroughly quantify whether and how PUFAR was related to DR as well as its role in DR detection.

METHODS

This two-centre case-control study was conducted from August 2017 to June 2018 in China, participants were matched using a propensity score matching algorithm. We adopted multivariable logistic regression models and restricted cubic spline analyses to estimate the independent association of PUFAR with DR, adjusting for confounders identified using a directed acyclic graph. The value of PUFAR as a biomarker for DR identification was further evaluated by receiver operating characteristic analyses and Hosmer-Lemeshow tests.

FINDINGS

An apparent negative relationship between PUFAR and DR was observed. Adjusted odds of DR decreased by 79% (OR: 0·21, 95% CI: 0·10-0·40) with an interquartile range increase in PUFAR. Similar results were also obtained in tertile analysis. As compared to those in the 1st tertile of PUFAR, the adjusted odds of DR decreased by 76% (OR: 0·24, 95% CI: 0·08-0·66) and 93% (OR: 0·07, 95% CI: 0·03-0·22) for subjects in the 2nd and 3rd tertiles, respectively. Good calibration and discrimination of the PUFAR associated predictive model were detected and PUFAR = 35 would be an ideal cut-off value for DR identification.

INTERPRETATION

Our results suggest that serum PUAFR is inversely associated with DR. Although PUFAR-alteration is not observed amongst different stages of DR, it can serve as an ideal biomarker in distinguishing patients with DR from those without DR.

FUNDING

This study was funded by Natural Science Foundation of Zhejiang Province, Zhejiang Basic Public Welfare Research Project, the Major Project of the Eye Hospital of Wenzhou Medical University, and the Academician's Science and Technology Innovation Program in Zhejiang province. Part of this work was also funded by the National Nature Science Foundation of China, and Research Project for College Students in Wenzhou Medical University.

Pseudotargeted Lipidomics Strategy Enabling Comprehensive Profiling and Precise Lipid Structural Elucidation of Polyunsaturated Lipid-Rich Echium Oil

Echium oil has great nutritional value as a result of its high content of α-linolenic acid (ALA, 18:3ω-3) and stearidonic acid (SDA, 18:4ω-3). However, the comprehensive lipid profiling and exact structural characterization of bioactive polyunsaturated lipids in echium oil have not yet been obtained. In this study, we developed a novel pseudotargeted lipidomics strategy for comprehensive profiling and lipid structural elucidation of polyunsaturated lipid-rich echium oil. Our approach integrated untargeted lipidomics analysis with a targeted lipidomics strategy based on Paternò-Büchi (PB)-tandem mass spectrometry (MS/MS) using 2-acetylpyridine (2-AP) as the reaction reagent, allowing for high-coverage lipid profiling and simultaneous determination of C═C locations in triacylglycerols (TGs), diacylglycerols (DGs), free fatty acids (FFAs), and sterol esters (SEs) in echium oil. A total of 209 lipid species were profiled, among which 162 unsaturated lipids were identified with C═C location assignment and 42 groups of ω-3 and ω-6 C═C location isomers were discovered. In addition, relative isomer ratios of certain groups of lipid C═C location isomers were revealed. This pseudotargeted lipidomics strategy described in this study is expected to provide new insight into structural characterization of distinctive bioactive lipids in food.

Different Dietary N-3 Polyunsaturated Fatty Acid Formulations Distinctively Modify Tissue Fatty Acid and N-Acylethanolamine Profiles

We investigated the influence of different dietary formulation of n-3 polyunsaturated fatty acids (PUFA) on rat tissue fatty acid (FA) incorporation and consequent modulation of their bioactive metabolite N-acylethanolamines (NAE). For 10 weeks, rats were fed diets with 12% of fat from milk + 4% soybean oil and 4% of oils with different n-3 PUFA species: soybean oil as control, linseed oil rich in α-linolenic (ALA), Buglossoides arvensis oil rich in ALA and stearidonic acid (SDA), fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), Nannochloropsis microalga oil rich in EPA or Schizochytrium microalga oil rich in DHA. FA and NAE profiles were determined in plasma, liver, brain and adipose tissues. Different dietary n-3 PUFA distinctively influenced tissue FA profiles and consequently NAE tissue concentrations. Interestingly, in visceral adipose tissue the levels of N-arachidonoylethanolamide (AEA) and N-docosahexaenoylethanolamide (DHEA), NAE derived from arachidonic acid (AA) and DHA, respectively, significantly correlated with NAE in plasma, and circulating DHEA levels were also correlated with those in liver and brain. Circulating NAE derived from stearic acid, stearoylethanolamide (SEA), palmitic acid and palmitoylethanolamide (PEA) correlated with their liver concentrations. Our data indicate that dietary n-3 PUFA are not all the same in terms of altering tissue FA and NAE concentrations. In addition, correlation analyses suggest that NAE levels in plasma may reflect their concentration in specific tissues. Given the receptor-mediated tissue specific metabolic role of each NAE, a personalized formulation of dietary n-3 PUFA might potentially produce tailored metabolic effects in different pathophysiological conditions.

Combination of natural strategies to improve the oxidative stability of echium seed oil

Echium seed oil is an alternative source of omega 3 fatty acids but it is highly susceptible to oxidation. A combination of three natural strategies was proposed in this study aiming to improve the oxidative stability of echium oil obtained by pressing (PO) or solvent extraction (PSO), kept in the storage condition for 180 days or during the consumption for 30 days. Our results showed that the reduction of temperature was sufficient to keep the oil stable during storage for both samples. During the consumption time, the best stability was achieved by adding a mixture of antioxidants, composed of sinapic (500 ppm), ascorbic (250 ppm), and citric (150 ppm) acids, and/or 20% of high oleic sunflower oil. The combined strategies promoted a 34 to 80% reduction of peroxide value and 0 to 85% reduction of malondialdehyde concentrations in the samples, showing to be a feasible and natural alternative to improve the oxidative stability of echium oil. PRACTICAL APPLICATION: Our study successfully applied an optimized combination of simple and low-cost strategies to enhance the chemical stability of echium seed oil. As the use of echium oil expands around the world, the oil industry and final consumers may benefit from our results to increase the oil shelf-life.

Effect of Food with Low Enrichment of N-3 Fatty Acids in a Two-Month Diet on the Fatty Acid Content in the Plasma and Erythrocytes and on Cardiovascular Risk Markers in Healthy Young Men

Polyunsaturated fatty acids of the n-3 series (n-3 PUFA) exhibit a number of favorable effects on the human organism and it is desirable to increase their intake in the diet. For this purpose, flaxseed oil was added to a chicken-feed mixture for the production of meat and eggs. The content of n-3 PUFA in the obtained meat was increased from 250 mg (reference value) to 900 mg in 100 g of meat and from 110 mg (reference value) to 190 mg in 100 g of whole egg; the enriched products are designated as omega-3 meat and omega-3 eggs. Omega-3 meat and eggs were subsequently fed for a period of eight weeks in an amount of 480 g of meat and four eggs (228 g netto) a week to a group of 14 healthy volunteers, whose body composition parameters were measured and blood was analyzed biochemically to determine blood lipids, coagulation parameters, plasma, and erythrocyte fatty acid spectrum composition. A control group of 14 volunteers was fed normal chicken and eggs in the same regime. The performed dietary intervention increases the intake of long-chain PUFA (LC-PUFA) by 37 mg per day, which represents 7–15% of the recommended daily dose. The performed tests demonstrated that the consumption of omega-3 enriched meat and eggs significantly increases the content of n-3 PUFA in the erythrocytes, which are a long-term indicator of fatty acid intake. This intervention has no demonstrable effect on the basic body parameters, such as body weight, fat content, Body Mass Index (BMI), and also on the plasma cholesterol level, high-density lipoprotein (HDL), low-density lipoprotein (LDL), blood clotting and inflammation markers, and omega-3 index.