Immuno‐Resolving Ability of Resolvins,Protectins, and Maresins Derived from Omega‐3 Fatty Acids in Metabolic Syndrome

Omega‐3 fatty acid consumption has been suggested to be beneficial for the prevention of type 2 diabetes mellitus (T2DM). Its effects have been attributed to anti‐inflammatory activity, with the inhibition of arachidonic acid metabolism playing a central role. However, a more recent view is that omega‐3 fatty acids play an active role as the precursors of potent, specialized pro‐resolving mediators (SPMs), such as resolvins, protectins, and maresins. Docosahexaenoic acid (DHA)‐ and eicosapentaenoic‐acid‐derived SPMs are identified in the adipose tissue but the levels of certain SPMs (e.g., protectin D1) are markedly reduced with obesity, suggesting adipose SPM deficiency, potentially resulting in unresolved inflammation. Supplementation of the biosynthetic intermediates of SPM (e.g., 17‐hydroxy‐DHA) or omega‐3 fatty acids increases the level of adipose SPMs, reduces adipose inflammation (decrease in macrophage accumulation and change to less inflammatory macrophages), and enhances insulin sensitivity. The findings from studies using rodent obesity models must be translated to humans. It will be important to further elucidate the underlying mechanisms by which obesity reduces the levels of and the sensitivity to SPM in adipose tissues. This will enable the development of nutrition therapy to enhance the effects of omega‐3 fatty acids in the prevention and/or treatment of T2DM.     

The New Paradigm for Lipid Oxidation and Insights to Microencapsulation of Omega‐3 Fatty Acids

The consumption of omega‐3 fatty acids provides a wide range of health benefits. However, the incorporation of these fatty acids in foods is limited because of their high oxidative instability. A new paradigm has emerged to better explain the oxidation mechanism of polyunsaturated fatty acids, which will be discussed here with reference to bulk lipids considered a special case of water in oil microemulsion. This paradigm suggests that lipid oxidation reactions are initiated by heterogeneous catalysis by metal oxides followed by the formation of micelles containing initial hydroperoxides, water, and other amphiphilic compounds. The induction period comes to the end when the formed micelles reach a critical micelle concentration and start to decompose opening the way to intense free radical reactions. Antioxidants and synergists extend the induction period not only by scavenging free radicals but also by stabilizing the micelles. With better understanding of the lipid oxidation mechanism, a tailored choice of antioxidants and synergistic combinations, and efficient encapsulation methods may be optimized to provide stable encapsulates containing highly n‐3 polyunsaturated fatty acids. Smart processing and encapsulation technologies utilizing properly stabilized oils as well as optimized packaging parameters aiming to enhance n‐3 fatty acid stability by smart selection/design of antioxidants, control of the interfacial physics and chemistry, and elimination of surface oil are needed for this purpose.     

Effects of Enrichment with Polyunsaturated Fatty Acids (Omega‐3 and Conjugated Linoleic Acid) on Consumer Liking of Beef Aged for 7 or 21 d Evaluated at Different Locations

The effect of different animal diets supplemented with linseed (source of omega‐3 fatty acids: n‐3) and/or conjugated linoleic acid (CON: control, LIN: 10% linseed, CLA: 2% conjugated linoleic acid, LINCLA: 10% linseed plus 2% CLA) on consumer liking of beef aged for 7 or 21 d was assessed in 3 Spanish cities. Overall, tenderness, juiciness, and flavor liking of beef were evaluated by consumers (n = 720) using 9‐point scales. Hedonic scores assigned by consumers did not differ (P > 0.05) for beef from animals fed the different diets and aged for 7 or 21 d. Consumer scores showed an increasing trend in beef liking with aging time. Consumers from Pamplona assigned lower (P < 0.05) hedonic scores for beef liking than consumers from Barcelona and Zaragoza. Linseed and/or CLA can be fed to improve the fatty acid profile in beef with minimal impact on consumer liking. Consumer ratings seem to depend on regional tastes and preferences.     

Manipulation of Omega‐3 PUFAs in Lamb: Phenotypic and Genotypic Views

A number of studies have shown that dietary omega‐6 and omega‐3 long‐chain fatty acids can be incorporated into muscle tissue of ruminants despite the biohydrogenation of dietary fatty acids in the rumen. The main focus of this review is on eicosapentaenoic (20:5n‐3) and docosahexaenoic (22:6n‐3) fatty acids because health authorities around the world consider the sum of these fatty acids as the basis of classifying a food as a source or good source of omega‐3 polyunsaturated fatty acids (PUFAs). A high proportion of polyunsaturated fatty acids are hydrogenated in the rumen, leading to a higher concentration of 18:0, but some escapes the rumen to be absorbed intact by the small intestine. Feeding strategies for ruminants have been successfully applied to increase the absorption of PUFAs in the small intestine and therefore to increase the levels of PUFAs in muscle tissue. Protected fats and algae are strong candidates to improve the nutritional value of red meat in ruminants in terms of health‐claimable omega‐3 fatty acids. Efforts to understand the genetic basis of fatty acid metabolism have been underway. The knowledge of the main genes which control the output of omega‐3 fatty acids is still lacking, but gene expression studies have helped to explain the deposition of these acids in muscle, liver, and subcutaneous fat.     

Olive Oil Phenolics Prevent Oxysterol‐Induced Proinflammatory Cytokine Secretion and Reactive Oxygen Species Production in Human Peripheral Blood Mononuclear Cells,Through Modulation of p38 and JNK Pathways

1 Scope

The aim of the present study was to investigate the ability of extra virgin olive oil (EVOO) polyphenols to counteract the proinflammatory effects induced by dietary and endogenous oxysterols in ex vivo immune cells.

2 Methods and results

Peripheral blood mononuclear cells (PBMCs), separated from the whole blood of healthy donors, were utilized and were stimulated with an oxysterols mixture, in the presence of physiologically relevant concentrations of the EVOO polyphenols, hydroxytyrosol, tyrosol, and homovanillic alcohol. Oxysterols significantly increased the production of proinflammatory cytokines, interleukin‐1β, regulated on activation, normal T‐cell expressed and secreted and macrophage migration inhibitory factor in ex vivo cultured PBMCs. Increased levels of reactive oxygen species (ROS) were also detected along with increased phosphorylation of the p38 and JNK. All phenolic compounds significantly reduced cytokine secretion induced by the oxysterols and inhibited ROS production and mitogen activated protein kinase phosphorylation.

3 Conclusions

These results suggest that extra virgin olive oil polyphenols modulate the immune response induced by dietary and endogenous cholesterol oxidation products in human immune cells and may hold benefit in controlling chronic immune and/or inflammatory processes.     

Effects of Long‐Chain and Medium‐Chain Fatty Acids on Apoptosis and Oxidative Stress in Human Liver Cells with Steatosis

Nonalcoholic fatty liver disease (NAFLD) is closely associated with obesity‐related metabolic complications, which caused by excess energy intake and physical inactivity apart from genetic defects. The mechanisms that promote disease progression from NAFLD to further liver injury are still unclear. We hypothesize that the progression involved “2nd hit” is strongly influenced by the type of fatty acids in diets. Flow cytometric analysis showed that medium‐chain fatty acid (MCFA) markedly decreased the percentage of late apoptotic and necrotic cells compared with long‐chain fatty acid (LCFA), and MCFA inhibited the activities of caspase‐3 and ‐9 in human liver cells with steatosis. Western blot analysis found that the levels of inflammatory markers (interleukin [IL]‐6, IL‐1‐β, and tumor necrosis factor‐α) were substantially reduced by MCFA compared with LCFA. Proteomic analysis further showed that LCFA inhibited the expression of antioxidant enzymes, and increased the expression of proteins associated with oxidative stress. It was found that LCFA (palmitate), not MCFA induced apoptosis, oxidative stress and chronic inflammatory responses in the hepatic cells with steatosis. In conclusion, reasonable selection of dietary fats has potential to translate therapeutically by ameliorating disease progression in patients with NAFLD.     

低温诱导球等鞭金藻3011脂肪酸去饱和酶基因片段的筛选及mRNA表达分析

本实验通过设计特异引物序列,对经低温诱导处理的球等鞭金藻3011的脂肪酸去饱和酶基因片段进行筛选,以实时荧光定量聚合酶链式反应检测酶的表达量,探索低温对该多不饱和脂肪酸脱饱和酶基因表达量的影响。结果表明：用prime5设计包括内参基因在内的14 条引物,其中7 条引物具有特异性扩增,根据扩增效果对其扩增体系进行优化。结果表明：Des4、Des5、Des6、Des8、Des9和Des12 mRNA相对最大表达量分别为7.71、11.33、42.58、22.02、73.91和16.01。随温度的降低均呈现先增加后降低的趋势。根据SPSS 19.0统计分析,6 个基因在其mRNA相对表达量最大的诱导时间时,18 ℃的mRNA相对表达量与其在12、15、21 ℃ 3 个温度条件下的相对表达量相比具有极显著差异（P＜0.01）。18 ℃条件下诱导24 h可以有效增加Des9基因在球等鞭金藻3011中的表达。此研究结果为人为调控微藻的多不饱和脂肪酸含量提供了一条可行的方法。     

Fatty Acid Composition Including Trans‐Fatty Acids in Edible Oils and Fats: Probable Intake in Indian Population

Abstract: The susceptibility of trans‐fat to the human health risk prompted the Food and Agriculture Organization (FAO) and World Health Organization (WHO) to prepare regulations or compulsory claims for trans‐fatty acids (TFA) in edible oils and fats. In this study, analysis of fatty acid composition and TFA content in edible oils and fats along with the possible intake of trans‐fat in Indian population was carried out. The analysis was carried out as per the Assn. of Official Analytical Chemists (AOAC) methodology and the results were statistically analyzed. The average TFA content in nonrefined mustard and refined soybean oils exceeded by 1.16‐ to 1.64‐fold as compared to the Denmark limit of 2% TFA in fats and oils destined for human consumption. In branded/nonbranded butter and butter oil samples, average TFA limit exceeded by 4.2‐ to 9.5‐fold whereas hydrogenated vegetable oil (HVO) samples exceeded the limit by 9.8‐fold, when compared to Denmark standards. The probable TFA intake per day through different oils in Indian population were found to be less than WHO recommendation. However Punjab having highest consumption of HVO (–15 g/d) showed 1.09‐fold higher TFA intake than the WHO recommendation, which is alarming and may be one of the factors for high cardiovascular disease mortality rate that needs further elucidation. Thus there is a need to prescribe TFA limit for edible oil, butter, and butter oil in India and to reduce the already proposed TFA levels in HVO to safeguard the health of consumers. Practical Application: The probable daily intake of trans‐fatty acid (TFA) especially through hydrogenated vegetable oil (HVO) was assessed. In absence of any specification for TFA and fatty acid composition for edible oils, butter, and butter samples, a pressing need was felt to prescribe TFA limit in India. The study indicates that TFA intake through HVO consumption is higher in States like Punjab than the recommended daily intake prescribed by WHO. Hence, strategies should be adopted to either decrease the consumption of HVO or to modify the industrial processing method of HVO with less content of TFA to safeguard the health of consumers.     

Enzymatic Synthesis of Refined Olive Oil‐Based Structured Lipid Containing Omega ‐3 and ‐6 Fatty Acids for Potential Application in Infant Formula

Structured lipids (SLs) containing palmitic, docosahexaenoic (DHA), and gamma‐linolenic (GLA) acids were produced using refined olive oil, tripalmitin, and ethyl esters of DHA single cell oil and GLA ethyl esters. Immobilized Lipozyme TL IM lipase was used as the biocatalyst. The SLs were characterized for fatty acid profile, triacylglycerol (TAG) molecular species, solid fat content, oxidative stability index, and melting and crystallization profiles and compared to physical blend of substrates, extracted fat from commercial infant formula (IFF), and milk fat. 49.28 mol% of palmitic acid was found at the sn‐2 position of SL TAG and total DHA and GLA composition were 0.73 and 5.00 mol%, respectively. The total oleic acid content was 36.13 mol% which was very close to the 30.49% present in commercial IFF. Comparable solid fat content profiles were also found between SLs and IFF. The SLs produced have potential for use in infant formulas.     

Effects of Different Simple Triglycerides on Cell Fatty Acid Compositions,Proliferation‐Related Protein,and Gene Expressions Induced by Oxidized‐LDL in HUVSMCs

The proliferating effects of 3 different simple triglycerides (tristearin, triolein, and trilinolein) on the human umbilical vein smooth muscle cells (HUVSMCs) induced by oxidized‐LDL (ox‐LDL) were investigated in this study. The protein and mRNA gene expressions of proliferating cell nuclear antigen (PCNA), smooth muscle‐α‐actin (SM‐α‐actin), and monocyte chemoattractant protein‐1 (MCP‐1) in HUVSMCs were measured by Western blotting and real‐time quantitative polymerase chain reaction (PCR). It was shown that in tristearin (SSS) treated HUVSMCs, the saturated fatty acid content was increased, and the compositions of polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid were decreased significantly. On the other hand, triolein (OOO) and trilinolein (LLL) significantly increased the levels of some typical PUFA such as arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. Moreover, LLL and OOO could upregulate the protein and mRNA expressions of PCNA, MCP‐1 as well as downregulate the expression of SM‐α‐actin. The results also showed that, SSS had significant promotion effects on the proliferation of HUVSMCs induced by ox‐LDL. Although both LLL and OOO could inhibit the proliferation of HUVSMCs induced by ox‐LDL, and might have certain inhibition of the atherosclerotic process.     

Rising Atmospheric CO2 Lowers Concentrations of Plant Carotenoids Essential to Human Health: A Meta‐Analysis

Plant and human tissues (e.g., leaves, retina) share the need for carotenoids to protect against light‐induced and other oxidative stresses. While plants synthesize carotenoids de novo, humans must obtain them primarily through plant‐based foods. In plants, elevated levels of atmospheric carbon dioxide (eCO₂) decrease the concentrations of essential minerals, including magnesium and zinc (essential for brain and eye health), but the overall effect of globally rising CO₂ levels on carotenoids is unknown. Here, investigation is sought on how eCO₂ affects carotenoids in plants. A meta‐analysis of 1026 experimental observations from 37 studies shows that eCO₂ decreases plant carotenoid concentrations by 15% (95% CI: ?26% to ?6%). The meta‐analysis of available gene expression data for Arabidopsis thaliana points to a potential CO₂‐induced downregulation of carotenoid biosynthesis (Log2 fold‐change ?13%, 95% CI: ?17% to ?9%). Some other stoichiometric and biochemical mechanisms related to CO₂‐induced changes in carotenoids are also highlighted. While overall eCO₂ decreases carotenoid concentrations, individual CO₂ studies report variable responses, including increases in carotenoid levels, especially in abiotically stressed plants. The initial assessment raises a novel question about the potential effects of rising CO₂ on human health through its global effect on plant carotenoids.