Fish oil decreases macrophage tumor necrosis factor gene transcription by altering the NF kappa B activity

The Role of Lipids in the Regulation of Immune Responses

Lipid metabolism plays a major role in the regulation of the immune system. Exogenous (dietary and microbial-derived) and endogenous (non-microbial-derived) lipids play a direct role in regulating immune cell activation, differentiation and expansion, and inflammatory phenotypes. Understanding the complexities of lipid-immune interactions may have important implications for human health, as certain lipids or immune pathways may be beneficial in circumstances of acute infection yet detrimental in chronic inflammatory diseases. Further, there are key differences in the lipid effects between specific immune cell types and location (e.g., gut mucosal vs. systemic immune cells), suggesting that the immunomodulatory properties of lipids may be tissue-compartment-specific, although the direct effect of dietary lipids on the mucosal immune system warrants further investigation. Importantly, there is recent evidence to suggest that lipid-immune interactions are dependent on sex, metabolic status, and the gut microbiome in preclinical models. While the lipid-immune relationship has not been adequately established in/translated to humans, research is warranted to evaluate the differences in lipid-immune interactions across individuals and whether the optimization of lipid-immune interactions requires precision nutrition approaches to mitigate or manage disease. In this review, we discuss the mechanisms by which lipids regulate immune responses and the influence of dietary lipids on these processes, highlighting compelling areas for future research.

Effects of Polyunsaturated Fatty Acids on Colorectal Cancer Patients: A Meta-Analysis of Randomized Controlled Trials

This study aimed to investigate the effects of polyunsaturated fatty acids (PUFAs) on patients with colorectal cancer (CRC). Electronic databases such as PubMed and Web of Science were searched. Studies on the application of PUFAs in patients with CRC, published up to January 2022, were conducted. Twelve studies involving 702 CRC patients were included. For patients undergoing surgery, subgroup analyses indicated that preoperative supplementation with PUFAs improved total postoperative infectious complications (RR: 0.37, p = 0.02). Furthermore, the supplementation of PUFAs in preoperative (WMD: -2.27, p < 0.001) and postoperative (WMD: -2.66, p = 0.01) groups was effective in shortening the postoperative hospital stay for patients with CRC. Tumor necrosis factor-α (TNF-α) (SMD: -0.56, p = 0.007) and interleukin-6 (IL-6) (SMD: -0.54, p = 0.004) levels were lower in all CRC patients receiving PUFAs intervention than in the control group. Moreover, supplementation with PUFAs in chemotherapy patients significantly increased albumin (WMD: 0.48, p = 0.03) and decreased C-reactive protein (CRP) (WMD: -6.12, p = 0.02) compared to the control group. This study demonstrated that PUFAs intervention could diminish the total postoperative infection complications of CRC patients, shorten the postoperative hospital stay, and reduce inflammation.

Anti-inflammatory properties of neutral lipids, glycolipids, and phospholipids isolated from Ammodytes personatus eggs in LPS-stimulated RAW264.7 cells

In the present study, total lipids were extracted from Ammodytes personatus eggs and separated into neutral lipids, glycolipids, and phospholipids. The anti-inflammatory activity of the neutral lipids, glycolipids, and phospholipids was investigated in macrophages, as well as the fatty acid profiles of the lipids. Palmitic acid, oleic acid, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) were the primary fatty acids in the three fractionated lipids. Among the lipids, the phospholipids contained the highest concentration of polyunsaturated fatty acids (PUFAs), particularly DHA and EPA (31.89 and 16.93% of the total fatty acids, respectively). The anti-inflammatory effects of the three lipids isolated from A. personatus eggs were analyzed in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The three lipids significantly reduced nitric oxide (NO) production and the mRNA expression of immune-associated genes in a dose-dependent manner. All lipids down-regulated the protein expression of phosphorylated NF-κB-p65 and MAPK (p38, JNK, and ERK1/2) signaling pathways, suggesting that they could inhibit cell signaling pathways by activating NF-κB and MAPK. The expression of CD40 and CD86 in LPS-stimulated RAW264.7 cells was also significantly decreased by A. personatus lipids. Consequently, the neutral lipids, glycolipids, and phospholipids from A. personatus eggs could serve as anti-inflammatory agents.

Docosahexaenoic Acid Delivery Systems, Bioavailability, Functionality, and Applications: A Review

Docosahexaenoic acid (DHA), mainly found in microalgae and fish oil, is crucial for the growth and development of visual, neurological, and brain. In addition, DHA has been found to improve metabolic disorders associated with obesity and has anti-inflammatory, anti-obesity, and anti-adipogenesis effects. However, DHA applications in food are often limited due to its low water solubility, instability, and poor bioavailability. Therefore, delivery systems have been developed to enhance the remainder of DHA activity and increase DHA homeostasis and bioavailability. This review focused on the different DHA delivery systems and the in vitro and in vivo digestive characteristics. The research progress on cardiovascular diseases, diabetes, visual, neurological/brain, anti-obesity, anti-inflammatory, food applications, future trends, and the development potential of DHA delivery systems were also reviewed. DHA delivery systems could overcome the instability of DHA in gastrointestinal digestion, improve the bioavailability of DHA, and better play the role of its functionality.

Lipid-based regulators of immunity

Lipids constitute a diverse class of molecular regulators with ubiquitous physiological roles in sustaining life. These carbon-rich compounds are primarily sourced from exogenous sources and may be used directly as structural cellular building blocks or as a substrate for generating signaling mediators to regulate cell behavior. In both of these roles, lipids play a key role in both immune activation and suppression, leading to inflammation and resolution, respectively. The simple yet elegant structural properties of lipids encompassing size, hydrophobicity, and molecular weight enable unique biodistribution profiles that facilitate preferential accumulation in target tissues to modulate relevant immune cell subsets. Thus, the structural and functional properties of lipids can be leveraged to generate new materials as pharmacological agents for potently modulating the immune system. Here, we discuss the properties of three classes of lipids: polyunsaturated fatty acids, short-chain fatty acids, and lipid adjuvants. We describe their immunoregulatory functions in modulating disease pathogenesis in preclinical models and in human clinical trials. We conclude with an outlook on harnessing the diverse and potent immune modulating properties of lipids for immunoregulation.

Role of omega 3 and omega 6 poly unsaturated fatty acids (PUFA) and vitamin D deficiency as risk determinants of metabolic syndrome in obesity: Worksite based case-control observational study

BACKGROUND AND AIMS

Risk factors for metabolic syndrome among obese population are not clear. The role of Eicosapentaenoic acid (EPA), Arachidonic acid (AA) Poly Unsaturated Fatty Acids (PUFA), their ratio and vitamin D deficiency as risk factors of metabolic syndrome (MS) was explored in obese worksite workers.

METHODS

The 145 obese worksite workers were enrolled and MS was diagnosed using adult treatment panel III criteria. The levels of EPA, AA PUFA were estimated using liquid chromatography-Mass Spectrometer and vitamin D levels with ELISA method. The association of MS with the tertiles of EPA, AA PUFAs, their ratio and vitamin D was estimated by calculating odds ratio and 95% C.I., taking lowest tertiles as the reference group using logistic regression model adjusted for age and gender.

RESULTS

105 out of 145 obese worksite workers; 72.4%, 95% C.I. (64.5%, 79.5%) had metabolic syndrome. The odd of MS was significantly lower in the group having highest tertiles of EPA 0.24 (0.09, 0.71) and was higher 2.0 (1.02, 3.89) in subjects with highest tertiles of AA: EPA ratio. The AA PUFA and vitamin D levels had no significant association with MS.

CONCLUSION

The low levels of omega 3 PUFA (EPA) and elevated ratio of AA: EPA PUFA was significantly associated with MS in obese works site workers.

Fatty acids in normal and pathological pregnancies

Long chain fatty acids, namely omega-3 and omega-6, are essential fatty acids and are necessary for proper pregnancy progression and fetal growth and development. Maternal fatty acid consumption and release of fatty acids from lipid stores provide increased availability of fatty acids for the placenta to transport to the growing fetus. Both omega-3 and omega-6 fatty acids are then utilized for generation of signaling molecules, such as eicosanoids, and for promoting of growth and developmental, most notably in the nervous system. Perturbations in fatty acid concentration and fatty acid signaling have been implicated in three major pregnancy complications - gestational diabetes, preeclampsia, and preterm birth. In this review we discuss the growing literature surrounding the role of fatty acids in normal and pathological pregnancies. Differences in maternal, placental, and fetal fatty acids and molecular regulation of fatty acid signaling and transport are presented. A look into novel fatty acid-based therapies for each of the highlighted disorders are discussed, and may present exciting bench to bedside alternatives to traditional pharmacological intervention.

Low Dietary n6/n3 Ratio Attenuates Changes in the NRF 2 Gene Expression, Lipid Peroxidation, and Inflammatory Markers Induced by Fructose Overconsumption in the Rat Abdominal Adipose Tissue

The objective of this study was to examine the benefits of different n6/n3 polyunsaturated fatty acid ratios on the lipid metabolism, insulin resistance, and oxidative stress in the adipose tissue of rats fed a high-fructose diet. Male and female rats were divided into four groups: a control group (CON) (n6/n3 ratio ~7), a high-fructose group (HF) (n6/n3 ratio ~7), an N6-HF group (n6/n3 ratio ~50), and the DHA-HF group (n6/n3 ratio ~1, with the addition of docosahexaenoic (DHA) and eicosapentaenoic (EPA) acid). The CON group received plain water and the HF group received 15% fructose in their drinking water. Fructose induced an increase in the content of serum triglycerides, serum cholesterol, and HOMA-IR index. Among the fatty acids, elevated proportions of C18:1n9 and C16:1n7, as well as an increase in total monounsaturated fatty acid (MUFA), were found in the adipose tissue of the HF group. Fructose treatment also changed oxidative parameters, including a marked increase in the serum malondialdehyde (MDA) content. Meanwhile, DHA supplementation caused a significant decrease in the serum MDA concentration in comparison with the HF group. In addition, DHA/EPA supplementation attenuated oxidative stress by increasing NRF 2 gene expression. Fructose treatment also significantly decreased the adiponectin level, while DHA supplementation ameliorated it. The changes observed in this trial, including the decrease in the content of DHA and EPA, the decreased EPA/ARA ratio, and the increase in the expression of inflammatory genes, are characteristics of the low-grade inflammation caused by fructose treatment. These changes in the rat adipose tissue could be prevented by dietary intervention consisting of DHA supplementation and a low n6/n3 ratio.

N-3 PUFA as an ergogenic supplement modulating muscle hypertrophy and strength: a systematic review

There is growing evidence that suggests that n-3 polyunsaturated fatty acids (PUFA) may improve physical performance when combined with proper training through modulation of muscle hypertrophy, muscle strength, and delayed onset muscle soreness (DOMS). This systematic review aims to examine the effect and optimal dosage of n-3 PUFA supplementation on muscle hypertrophy, muscle strength, and DOMS when combined with physical exercise. The PubMed, Web of Science, MEDLINE Complete, CINAHL and SPORTDiscus databases were searched following the PRISMA guidelines. Randomized controlled trials performed with healthy humans were considered. Fifteen studies with a total of 461 individuals were included in this systematic review. All of them measured muscle function (short physical performance test, range of motion (ROM), electromechanical delay (EMD), muscle echo intensity or muscle quality) and DOMS. Fourteen studies evaluated muscle strength and only six assessed muscle hypertrophy. Our results demonstrated that n-3 PUFA does not improve muscle hypertrophy, muscle strength or skeletal muscle biomarkers of inflammation and muscle damage beyond the benefits obtained by the training itself. Nevertheless, n-3 PUFA improves DOMS recovery and muscle function (measured by ROM, EMD and muscle quality).

Can N-3 polyunsaturated fatty acids be considered a potential adjuvant therapy for COVID-19-associated cardiovascular complications?

Coronavirus disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has currently led to a global pandemic with millions of confirmed and increasing cases around the world. The novel SARS-CoV-2 not only affects the lungs causing severe acute respiratory dysfunction but also leads to significant dysfunction in multiple organs and physiological systems including the cardiovascular system. A plethora of studies have shown the viral infection triggers an exaggerated immune response, hypercoagulation and oxidative stress, which contribute significantly to poor cardiovascular outcomes observed in COVID-19 patients. To date, there are no approved vaccines or therapies for COVID-19. Accordingly, cardiovascular protective and supportive therapies are urgent and necessary to the overall prognosis of COVID-19 patients. Accumulating literature has demonstrated the beneficial effects of n-3 polyunsaturated fatty acids (n-3 PUFA) toward the cardiovascular system, which include ameliorating uncontrolled inflammatory reactions, reduced oxidative stress and mitigating coagulopathy. Moreover, it has been demonstrated the n-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are precursors to a group of potent bioactive lipid mediators, generated endogenously, which mediate many of the beneficial effects attributed to their parent compounds. Considering the favorable safety profile for n-3 PUFAs and their metabolites, it is reasonable to consider n-3 PUFAs as potential adjuvant therapies for the clinical management of COVID-19 patients. In this article, we provide an overview of the pathogenesis of cardiovascular complications secondary to COVID-19 and focus on the mechanisms that may contribute to the likely benefits of n-3 PUFAs and their metabolites.

Synthesis of Eicosapentaenoic acid-enriched Phosphatidylcholine and Its Effect on Pro-inflammatory Cytokine Expression

AIM AND OBJECTIVE

We synthesized eicosapentaenoic acid-enriched phosphatidylcholine (EPA-PC) and investigated its effect on the production of lipopolysaccharide (LPS)-induced cytokines in murine splenocytes.

MATERIAL AND METHODS

The culture supernatants of splenocytes, which was exposed to EPA-PC along with LPS, was harvested to determine the production of cytokines [interleukin (IL)-4 , IL-5, IL-6, interferon (IFN)-γ, IL-2 and IL-12/IL-23(p40)]. Cytokines were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The co-administration of EPA-PC with LPS resulted in a significantly lower IFN-γ expression than that observed with LPS alone (p < 0.01). Moreover, treatment with EPA-PC and LPS significantly decreased IL-2, IL-6 and IL-12/IL-23(p40) expression (p < 0.01). Co-administration of EPA-PC at a concentration of 0.3 μg/mL with LPS resulted in a higher IL-5 expression after 24 hr of treatment when compared to LPS alone (p < 0.05).

CONCLUSION

These results suggest that EPA-PC is more effective in decreasing the expression of pro-inflammatory cytokines [IL-2, IFN-γ, IL-6 and IL-12/IL-23(p40)] upon induction of inflammation.

Omega-3 fatty acid modulation of serum and osteocyte tumor necrosis factor-α in adult mice exposed to ionizing radiation

Chronic inflammation leads to bone loss and fragility. Proinflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) consistently promote bone resorption. Dietary modulation of proinflammatory cytokines is an accepted therapeutic approach to treat chronic inflammation, including that induced by space-relevant radiation exposure. As such, these studies were designed to determine whether an anti-inflammatory diet, high in omega-3 fatty acids, could reduce radiation-mediated bone damage via reductions in the levels of inflammatory cytokines in osteocytes and serum. Lgr5-EGFP C57BL/6 mice were randomized to receive diets containing fish oil and pectin (FOP; high in omega-3 fatty acids) or corn oil and cellulose (COC; high in omega-6 fatty acids) and then acutely exposed to 0.5-Gy ⁵⁶Fe or 2.0-Gy gamma-radiation. Mice fed the FOP diet exhibited consistent reductions in serum TNF-α in the ⁵⁶Fe experiment but not the gamma-experiment. The percentage osteocytes (%Ot) positive for TNF-α increased in gamma-exposed COC, but not FOP, mice. Minimal changes in %Ot positive for sclerostin were observed. FOP mice exhibited modest improvements in several measures of cancellous microarchitecture and volumetric bone mineral density (BMD) postexposure to ⁵⁶Fe and gamma-radiation. Reduced serum TNF-α in FOP mice exposed to ⁵⁶Fe was associated with either neutral or modestly positive changes in bone structural integrity. Collectively, these data are generally consistent with previous findings that dietary intake of omega-3 fatty acids may effectively mitigate systemic inflammation after acute radiation exposure and facilitate maintenance of BMD during spaceflight in humans.NEW & NOTEWORTHY This is the first investigation, to our knowledge, to test the impact of a diet high in omega-3 fatty acids on multiple bone structural and biological outcomes following space-relevant radiation exposure. Novel in biological outcomes is the assessment of osteocyte responses to this stressor. These data also add to the growing evidence that low-dose exposures to even high-energy ion species like ⁵⁶Fe may have neutral or even small positive impacts on bone.

EPA and DHA differentially modulate monocyte inflammatory response in subjects with chronic inflammation in part via plasma specialized pro-resolving lipid mediators: A randomized, double-blind, crossover study

BACKGROUND AND AIMS

The independent effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on chronic inflammation through their downstream lipid mediators, including the specialized pro-resolving lipid mediators (SPM), remain unstudied. Therefore, we compared the effects of EPA and DHA supplementation on monocyte inflammatory response and plasma polyunsaturated fatty acids (PUFA) SPM lipidome.

METHODS

After a 4-week lead-in phase (baseline), 9 men and 12 postmenopausal women (50-75 years) with chronic inflammation received two phases of 10-week supplementation with 3 g/day EPA and DHA in a random order, separated by a 10-week washout.

RESULTS

Compared with baseline, EPA and DHA supplementation differently modulated LPS-stimulated monocyte cytokine expression. EPA lowered TNFA (p < 0.001) whereas DHA reduced TNFA (p < 0.001), IL6 (p < 0.02), MCP1 (p < 0.03), and IL10 (p < 0.01). DHA lowered IL10 expression relative to EPA (p = 0.03). Relative to baseline, EPA, but not DHA, decreased the ratios of TNFA/IL10 and MCP1/IL10 (both p < 0.01). EPA and DHA also significantly changed plasma PUFA SPM lipidome by replacing n-6 AA derivatives with their respective derivatives including 18-hydroxy-EPA (+5 fold by EPA) and 17- and 14-hydroxy-DHA (+3 folds by DHA). However, DHA showed a wider effect than EPA by also significantly increasing EPA derivatives and DPA-derived SPM at a greater expense of AA derivatives. Different groups of PUFA derivatives mediated the differential effects of EPA and DHA on monocyte cytokine expression.

CONCLUSIONS

EPA and DHA had distinct effects on monocyte inflammatory response with a broader effect of DHA in attenuating pro-inflammatory cytokines. These differential effects were potentially mediated by different groups of PUFA derivatives, suggesting immunomodulatory activities of SPM and their intermediates.

Potential use of n-3 PUFAs to prevent oxidative stress-derived ototoxicity caused by platinum-based chemotherapy

Platinum-based compounds are widely used for the treatment of different malignancies due to their high effectiveness. Unfortunately, platinum-based treatment may lead to ototoxicity, an often-irreversible side effect without a known effective treatment and prevention plan. Platinum-based compound-related ototoxicity results mainly from the production of toxic levels of reactive oxygen species (ROS) rather than DNA-adduct formation, which has led to test strategies based on direct ROS scavengers to ameliorate hearing loss. However, favorable clinical results have been associated with several complications, including potential interactions with chemotherapy efficacy. To understand the contribution of the different cytotoxic mechanisms of platinum analogues on malignant cells and auditory cells, the particular susceptibility and response of both kinds of cells to molecules that potentially interfere with these mechanisms, is fundamental to develop innovative strategies to prevent ototoxicity without affecting antineoplastic effects. The n-3 long-chain polyunsaturated fatty acids (n-3 PUFAs) have been tried in different clinical settings, including with cancer patients. Nevertheless, their use to decrease cisplatin-induced ototoxicity has not been explored to date. In this hypothesis paper, we address the mechanisms of platinum compounds-derived ototoxicity, focusing on the differences between the effects of these compounds in neoplastic versus auditory cells. We discuss the basis for a strategic use of n-3 PUFAs to potentially protect auditory cells from platinum-derived injury without affecting neoplastic cells and chemotherapy efficacy.

Influence of n-3 fatty acid supplementation on inflammatory and oxidative stress markers in patients with polycystic ovary syndrome: a systematic review and meta-analysis

Polycystic ovary syndrome (PCOS) is defined as a reproductive endocrine disease that results in a low-grade inflammatory and pro-oxidant state. Dietary factors, including n-3 fatty acids, may have a key role in improving metabolic disorders in PCOS patients. The present study aimed to investigate the influence of n-3 fatty acid supplementation on inflammatory and oxidative stress (OS) markers in patients with PCOS. A systematic literature search of Medline/PubMed, Cochrane Central Register of Controlled Trials, Scopus and Lilacs, until November 2019, was conducted. Randomised clinical trials that reported inflammatory and OS markers as endpoints in women with PCOS receiving n-3 fatty acid supplementation were included. The pooled estimates of the weighted mean differences (WMD) and the standard mean differences (SMD) were calculated. Random effects models were adopted to measure the pooled outcomes. Among the 323 studies retrieved, ten fulfilled the inclusion criteria for a meta-analysis. We founded a significant decrease in high-sensitivity C-reactive protein (hs-CRP) (SMD -0·29 (95 % CI -0·56, -0·02) mg/l) and an increase in adiponectin (WMD 1·42 (95 % CI 1·09, 1·76) ng/ml) concentrations in the intervention group when compared with the placebo group. No statistically significant results were found in the meta-analysis for visfatin, nitric oxide, GSH or malondialdehyde levels or total antioxidant capacity. The data suggest that supplementation of n-3 fatty acids could reduce the inflammatory state in women with PCOS, through a decrease in hs-CRP and an increase in adiponectin levels.

n-3 PUFA and inflammation: from membrane to nucleus and from bench to bedside

Inflammation is a normal part of the immune response and should be self-limiting. Excessive or unresolved inflammation is linked to tissue damage, pathology and ill health. Prostaglandins and leukotrienes produced from the n-6 fatty acid arachidonic acid are involved in inflammation. Fatty acids may also influence inflammatory processes through mechanisms not necessarily involving lipid mediators. The n-3 fatty acids EPA and DHA possess a range of anti-inflammatory actions. Increased content of EPA and DHA in the membranes of cells involved in inflammation has effects on the physical nature of the membranes and on the formation of signalling platforms called lipid rafts. EPA and DHA interfere with arachidonic acid metabolism which yields prostaglandins and leukotrienes involved in inflammation. EPA gives rise to weak (e.g. less inflammatory) analogues and both EPA and DHA are substrates for the synthesis of specialised pro-resolving mediators. Through their effects on early signalling events in membranes and on the profile of lipid mediators produced, EPA and DHA alter both intracellular and intercellular signals. Within cells, this leads to altered patterns of gene expression and of protein production. The net result is decreased production of inflammatory cytokines, chemokines, adhesion molecules, proteases and enzymes. The anti-inflammatory and inflammation-resolving effects of EPA and DHA are relevant to both prevention and treatment of human diseases that have an inflammatory component. This has been widely studied in rheumatoid arthritis where there is good evidence that high doses of EPA + DHA reduce pain and other symptoms.

Resolvin D5, a Lipid Mediator, Inhibits Production of Interleukin-6 and CCL5 Via the ERK-NF-κB Signaling Pathway in Lipopolysaccharide-Stimulated THP-1 Cells

One of the omega-3 essential fatty acids, docosahexaenoic acid (DHA), is a significant constituent of the cell membrane and the precursor of several potent lipid mediators. These mediators are considered to be important in preventing or treating several diseases. Resolvin D5, an oxidized lipid mediator derived from DHA, has been known to exert anti-inflammatory effects. However, the detailed mechanism underlying these effects has not yet been elucidated in human monocytic THP-1 cells. In the present study, we investigated the effects of resolvin D5 on inflammation-related signaling pathways, including the extracellular signal-regulated kinase (ERK)-nuclear factor (NF)-κB signaling pathway. Resolvin D5 downregulated the production of interleukin (IL)-6 and chemokine (C-C motif) ligand 5 (CCL5). Additionally, these inhibitory effects were found to be modulated by mitogen-activated protein kinase (MAPK) and NF-κB in lipopolysaccharide (LPS)-treated THP-1 cells. Resolvin D5 inhibited the LPS-stimulated phosphorylation of ERK and translocation of p65 and p50 into the nucleus, resulting in the inhibition of IL-6 and CCL5 production. These results revealed that resolvin D5 exerts anti-inflammatory effects in LPS-treated THP-1 cells by regulating the phosphorylation of ERK and nuclear translocation of NF-kappaB.

Bone Benefits of Fish Oil Supplementation Depend on its EPA and DHA Content

The preventive effect of high-dose (9%) regular-fish oil (FO) against bone loss during aging has been demonstrated, but the effects of a low-dose (1%–4%) of a highly purified concentrated FO (CFO) has not been elucidated. The aim of this study was to determine the dose-dependent effect of a CFO against bone loss in C57BL/6 female mice during aging. Twelve-month old mice were fed with 1% and 4% CFO and 4% safflower oil (SFO) diets, including a group with a 4% regular-FO diet and a group with a lab chow diet for 12 months. Bone mineral density (BMD) was analyzed by dual-energy x-ray absorptiometry (DXA) before and after the dietary intervention. At the end of dietary intervention, bone resorption markers in serum and inflammatory markers in bone marrow and splenocytes and inflammatory signaling pathways in the bone marrow were analyzed. As compared to the 4% SFO control, 4% CFO maintained higher BMD during aging, while 1% CFO offered only a mild benefit. However, the 1% CFO fed group exhibited slightly better BMD than the 4% regular-FO fed group. BMD loss protection by CFO was accompanied by reduced levels of the bone resorption marker, TRAP, and the osteoclast-stimulating-factor, RANKL, without affecting the decoy-receptor of RANKL, osteoprotegerin (OPG). Further, CFO supplementation was associated with an increase in the production of IL-10, IL-12, and IFN-γ and a decrease in the production of TNF-α and IL-6, and the activation of NF-κB, p38 MAPK, and JNK signaling pathways. In conclusion, the supplementation of 4% CFO is very efficient in maintaining BMD during aging, whereas 1% CFO is only mildly beneficial. CFO supplementation starting at middle age may maintain better bone health during aging.

Fenretinide favorably affects mucins (MUC5AC/MUC5B) and fatty acid imbalance in a manner mimicking CFTR-induced correction

Cystic fibrosis (CF) is the most common genetic disease in Caucasians. CF is manifested by abnormal accumulation of mucus in the lungs, which serves as fertile ground for the growth of microorganisms leading to recurrent infections and ultimately, lung failure. Mucus in CF patients consists of DNA from dead neutrophils as well as mucins produced by goblet cells. MUC5AC mucin leads to pathological plugging of the airways whereas MUC5B has a protective role against bacterial infection. Therefore, decreasing the level of MUC5AC while maintaining MUC5B intact would in principle be a desirable mucoregulatory treatment outcome. Fenretinide prevented the lipopolysaccharide-induced increase of MUC5AC gene expression, without affecting the level of MUC5B, in a lung goblet cell line. Additionally, fenretinide treatment reversed the pro-inflammatory imbalance of fatty acids by increasing docosahexaenoic acid and decreasing the levels of arachidonic acid in a lung epithelial cell line and primary leukocytes derived from CF patients. Furthermore, for the first time we also demonstrate the effect of fenretinide on multiple unsaturated fatty acids, as well as differential effects on the levels of long- compared to very-long-chain saturated fatty acids which are important substrates of complex phospholipids. Finally, we demonstrate that pre-treating mice with fenretinide in a chronic model of P. aeruginosa lung infection efficiently decreases the accumulation of mucus. These findings suggest that fenretinide may offer a new approach to therapeutic modulation of pathological mucus production in CF.

LIPid Intensive Drug therapy for Sepsis Pilot (LIPIDS-P): Phase I/II clinical trial protocol of lipid emulsion therapy for stabilising cholesterol levels in sepsis and septic shock

INTRODUCTION

Sepsis is a life-threatening, dysregulated response to infection. Both high-density lipoprotein and low-density lipoprotein cholesterol should protect against sepsis by several mechanisms; however, for partially unknown reasons, cholesterol levels become critically low in patients with early sepsis who experience poor outcomes. An anti-inflammatory lipid injectable emulsion containing fish oil is approved by the Food and Drug Administration as parenteral nutrition for critically ill patients and may prevent this decrease in serum cholesterol levels by providing substrate for cholesterol synthesis and may favourably modulate inflammation. This LIPid Intensive Drug therapy for Sepsis Pilot clinical trial is the first study to attempt to stabilise early cholesterol levels using lipid emulsion as a treatment modality for sepsis.

METHODS AND ANALYSIS

This is a two-centre, phase I/II clinical trial. Phase I is a non-randomised dose-escalation study using a Bayesian optimal interval design in which up to 16 patients will be enrolled to evaluate the safest and most efficacious dose for stabilising cholesterol levels. Based on phase I results, the two best doses will be used to randomise 48 patients to either lipid injectable emulsion or active control (no treatment). Twenty-four patients will be randomised to one of two doses of the study drug, while 24 control group patients will receive no drug and will be followed during their hospitalisation. The control group will receive all standard treatments mandated by the institutional sepsis alert protocol. The phase II study will employ a permuted blocked randomisation technique, and the primary endpoint will be change in serum total cholesterol level (48 hours - enrolment). Secondary endpoints include change in cholesterol level from enrolment to 7 days, change in Sequential Organ Failure Assessment score over the first 48 hours and 7 days, in-hospital and 28-day mortality, lipid oxidation status, inflammatory biomarkers, and high-density lipoprotein function.

ETHICS AND DISSEMINATION

Investigators are trained and follow good clinical practices, and each phase of the study was reviewed and approved by the institutional review boards of each institution. Results of each phase will be disseminated through presentations at national meetings and publication in peer-reviewed journals. If promising, data from the pilot study will be used for a larger, multicentre, phase II clinical trial.

TRIAL REGISTRATION NUMBER

NCT03405870.

Are immunotherapies for Huntington's disease a realistic option?

There is compelling evidence that the pathophysiology of many neurodegenerative diseases includes dysregulation of the immune system, with some elements that precede disease onset. However, if these alterations are prominent, why have clinical trials targeting this system failed to translate into long-lasting meaningful benefits for patients? This review focuses on Huntington's disease, a genetic disorder marked by notable cerebral and peripheral inflammation. We summarize ongoing and completed clinical trials that have involved pharmacological approaches to inhibit various components of the immune system and their pre-clinical correlates. We then discuss new putative treatment strategies using more targeted immunotherapies such as vaccination and intrabodies and how these may offer new hope in the treatment of Huntington's disease as well as other neurodegenerative diseases.

Effectiveness of Fish Oil Supplementation in Attenuating Exercise-Induced Muscle Damage in Women During Midfollicular and Midluteal Menstrual Phases

McKinley-Barnard, SK, Andre, TL, Gann, JJ, Hwang, PS, and Willoughby, DS. Effectiveness of fish oil supplementation in attenuating exercise-induced muscle damage in females during midfollicular and midluteal menstrual phases. J Strength Cond Res 32(6): 1601-1612, 2018-The purpose of this study was to determine whether the differences in estrogen levels during the female menstrual cycle and fish oil supplementation would attenuate eccentric exercise-induced muscle damage and delayed-onset muscle soreness (DOMS). In a double-blind fashion, 22 physically active females (20.9 ± 1.4 years, 63.5 ± 9.0 kg, 165.2 ± 7.5 cm) were randomly assigned to ingest either 6 g of fish oil (n = 11) or placebo (n = 11) daily for 21 days. Participants underwent an eccentric exercise bout of the knee extensors on 2 occasions during the midfollicular (MF) and midluteal (ML) phases of the 28-day menstrual cycle. Before (PRE), at 6 (6HRPOST), and at 24 hours postexercise (24HRPOST) for each session, participants underwent assessments of DOMS, muscle strength, and had venous blood samples and muscle biopsies obtained. Data were analyzed using a 2 × 2 × 3 repeated-measures multivariate analysis of variance for each criterion variable (p ≤ 0.05). Further analysis of the main effects for the test was performed using separate 1-way analyses of variance. Delayed-onset muscle soreness was significantly greater at the 6HRPOST and 24HRPOST timepoints compared with PRE (p < 0.001). Superoxide dismutase and tumor necrosis factor-alpha (TNF-α) concentrations were significantly higher at the MF phase compared with the ML phase (p < 0.001 and p = 0.05, respectively). There were no statistically significant differences observed for muscle strength, myoglobin, NF-Kβ p50, or NF-Kβ p65. This study demonstrates that higher levels of estrogen may exert a cytoprotective effect on the sarcolemma.

Inflammatory response following in vitro exposure to methylmercury with and without n-3 long chain polyunsaturated fatty acids in peripheral blood mononuclear cells from systemic lupus erythematosus patients compared to healthy controls

Methylmercury (MeHg) is a proposed environmental stimulus in systemic lupus erythematosus (SLE). Humans are primarily exposed to MeHg through fish consumption. Fish are also important sources of n-3 long chain polyunsaturated fatty acids (n-3 LCPUFA). This in vitro study investigated the inflammatory response of isolated peripheral blood mononuclear cells (PBMCs), when exposed to either MeHg alone or with added n-3 LCPUFA, from SLE patients (N = 12) compared to healthy sex matched controls (N = 12). The PBMCs were isolated and exposed to 200 nM of MeHg for 24 h with or without pre-exposure to eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) at a concentration of 100 μM each. Supernatants were analyzed for the inflammatory markers. Following exposure to MeHg_, mean TNF-α concentrations were significantly higher in SLE patients (2226.01 ± 348.98pg/ml) compared to controls (701.40 ± 680.65 pg/ml) (P = .008). Pre-exposure of cells with MeHg and EPA resulted in a significantly higher concentration of IL-8 in supernatants from SLE patients (2137.83 ± 1559.01 pg/ml) compared to that of the controls (879.26 ± 979.49 pg/ml) (P = .030). EPA and DHA attenuated the pro-inflammatory inducing effects of MeHg in SLE and control cells. In summary, exposure to MeHg stimulated a higher TNF-α response in SLE patients compared with healthy controls; nevertheless the presence of n-3 LCPUFA reduced the overall inflammatory response, albeit to a lesser degree in SLE patients.

Fish oil feeding reverses hepatomegaly and disrupted hepatic function due to the lack of FXR signaling

Mice lacking farnesoid X receptor (FXR) are used as a model for nonalcoholic fatty liver disease because their livers exhibit hepatomegaly, hepatic steatosis, and hepatic inflammation. The influence of fish oil feeding on hepatomegaly and disrupted hepatic function was investigated using female Fxr-null mice and wild-type mice fed a fish oil diet (2% fish oil and 2% corn oil) or a control diet (4% corn oil) for 4 weeks. Hepatic n-3 polyunsaturated fatty acid (PUFA) levels, including 22:6 n-3 docosahexaenoic acid (DHA) and 20:5 n-3 eicosapentaenoic acid (EPA) were significantly higher in the fish oil group than those in the control group of Fxr-null mice and wild-type mice. Fxr-null mouse livers of the control group showed a whitish brown coloration, whereas Fxr-null mouse livers of the fish oil group showed a dark brown coloration similar to that of wild-type mice. The liver in Fxr-null mice of the fish oil group was smaller than that of the control group. There was a significant decrease in the levels of hepatic damage-associated diagnostic markers, hepatic and serum bile acids, triglycerides, free fatty acids, and total cholesterol levels in Fxr-null mice because of fish oil feeding. It also reversed elevated mRNA levels of oxidative stress-related genes (Hmox1, Gsta1, and Gsta2) and reduced mRNA levels of transcriptional factors (Pparα and Shp) in Fxr-null mice. These results suggest that fish oil feeding reverses hepatomegaly and disrupted hepatic function due to the lack of FXR signaling.

Omega-3 fatty acids in obesity and metabolic syndrome: a mechanistic update

Strategies to reduce obesity have become public health priorities as the prevalence of obesity has risen in the United States and around the world. While the anti-inflammatory and hypotriglyceridemic properties of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) are well known, their antiobesity effects and efficacy against metabolic syndrome, especially in humans, are still under debate. In animal models, evidence consistently suggests a role for n-3 PUFAs in reducing fat mass, particularly in the retroperitoneal and epididymal regions. In humans, however, published research suggests that though n-3 PUFAs may not aid weight loss, they may attenuate further weight gain and could be useful in the diet or as a supplement to help maintain weight loss. Proposed mechanisms by which n-3 PUFAs may work to improve body composition and counteract obesity-related metabolic changes include modulating lipid metabolism; regulating adipokines, such as adiponectin and leptin; alleviating adipose tissue inflammation; promoting adipogenesis and altering epigenetic mechanisms.

Brominated indoles from a marine mollusc inhibit inflammation in a murine model of acute lung injury

New drug leads for the treatment of inflammation are urgently needed. Marine molluscs are widely used as traditional medicines for the treatment of inflammation. Here we report the positive effects of a hypobranchial gland (HBG) extract and the dominant bioactive compound 6-bromoisatin from the Muricidae mollusc Dicathais orbita, for reducing lipopolysaccharide (LPS) induced acute lung inflammation in a mouse model. Both 6-bromoisatin and the HBG extract suppressed the inflammatory response in mice that were pre-treated by oral gavage at 48, 24 and 1 h prior to LPS infusion. The inflammatory antagonists were tested at concentrations of 0.5 mg/g and 0.1 mg/g HBG extract and 0.1 mg/g and 0.05 mg/g 6-bromoisatin in carrier oil and all treatments reduced inflammation as indicated by a significant suppression of inflammatory markers present in bronchoalveolar lavage fluid (BALF), in comparison to LPS induced positive control mice administered the carrier oil alone (p < 0.0001). Tumour necrosis factor-alpha (TNFα) and interleukin-1 beta (IL-1β) levels, in addition to total protein concentration were all significantly reduced in BALF from mice treated with the extract or 6-bromoisatin. Furthermore, all treatment groups showed significant reductions in neutrophil sequestration and preservation of the lung tissue architecture compared to the positive control (p < 0.0001). The combined results from this study and our previous in vitro studies indicate that 6-bromoisatin in the HGB extracts inhibit the activation of inflammatory signalling pathway. The results from this study further confirm that the HBG extract from Muricidae molluscs and 6-bromoisatin are bioavailable and effective in vivo, thus have potential for development as natural therapeutic agents for inflammation.

Omega-3 fatty acids and inflammatory processes: from molecules to man

Inappropriate, excessive or uncontrolled inflammation contributes to a range of human diseases. Inflammation involves a multitude of cell types, chemical mediators and interactions. The present article will describe nutritional and metabolic aspects of omega-6 (n-6) and omega-3 (n-3) fatty acids and explain the roles of bioactive members of those fatty acid families in inflammatory processes. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 fatty acids found in oily fish and fish oil supplements. These fatty acids are capable of partly inhibiting many aspects of inflammation including leucocyte chemotaxis, adhesion molecule expression and leucocyte–endothelial adhesive interactions, production of eicosanoids like prostaglandins and leukotrienes from the n-6 fatty acid arachidonic acid and production of pro-inflammatory cytokines. In addition, EPA gives rise to eicosanoids that often have lower biological potency than those produced from arachidonic acid, and EPA and DHA give rise to anti-inflammatory and inflammation resolving mediators called resolvins, protectins and maresins. Mechanisms underlying the anti-inflammatory actions of EPA and DHA include altered cell membrane phospholipid fatty acid composition, disruption of lipid rafts, inhibition of activation of the pro-inflammatory transcription factor nuclear factor κB so reducing expression of inflammatory genes and activation of the anti-inflammatory transcription factor peroxisome proliferator-activated receptor γ. Animal experiments demonstrate benefit from EPA and DHA in a range of models of inflammatory conditions. Human trials demonstrate benefit of oral n-3 fatty acids in rheumatoid arthritis and in stabilizing advanced atherosclerotic plaques. Intravenous n-3 fatty acids may have benefits in critically ill patients through reduced inflammation. The anti-inflammatory and inflammation resolving actions of EPA, DHA and their derivatives are of clinical relevance.

Anti-Inflammatory Effects of Stearidonic Acid Mediated by Suppression of NF-κB and MAP-Kinase Pathways in Macrophages

Stearidonic acid (SDA, 18:4n-3) is an omega-3 polyunsaturated fatty acid present in oils derived from plants of the Boraginaceae family. In this study, we determined the anti-inflammatory effects of SDA isolated from echium oil on lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 macrophages. SDA significantly downregulated the levels of the inducible nitric oxide synthase (iNOS) protein, thereby suppressing the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells. In addition, SDA inhibited the nuclear translocation and promoter activity of nuclear factor κB (NFκB) and the phosphorylation of mitogen-activated protein kinases (MAPK) such as extracellular signal regulated kinase 1/2, c-jun N terminal kinase, and p38 in LPS-stimulated RAW 264.7 cells. Our results showed that SDA exerted anti-inflammatory effects by suppressing iNOS-mediated NO production via inactivation of NFκB and MAPK signaling pathways.

Anti-Inflammatory Activity and Structure-Activity Relationships of Brominated Indoles from a Marine Mollusc

Marine molluscs are rich in biologically active natural products that provide new potential sources of anti-inflammatory agents. Here we used bioassay guided fractionation of extracts from the muricid Dicathais orbita to identify brominated indoles with anti-inflammatory activity, based on the inhibition of nitric oxide (NO) and tumour necrosis factor α (TNFα) in lipopolysaccharide (LPS) stimulated RAW264.7 macrophages and prostaglandin E2 (PGE2) in calcium ionophore-stimulated 3T3 ccl-92 fibroblasts. Muricid brominated indoles were then compared to a range of synthetic indoles to determine structure-activity relationships. Both hypobranchial gland and egg extracts inhibited the production of NO significantly with IC₅₀ of 30.8 and 40 μg/mL, respectively. The hypobranchial gland extract also inhibited the production of TNFα and PGE2 with IC₅₀ of 43.03 µg/mL and 34.24 µg/mL, respectively. The purified mono-brominated indole and isatin compounds showed significant inhibitory activity against NO, TNFα, and PGE2, and were more active than dimer indoles and non-brominated isatin. The position of the bromine atom on the isatin benzene ring significantly affected the activity, with 5Br > 6Br > 7Br. The mode of action for the active hypobranchial gland extract, 6-bromoindole, and 6-bromoisatin was further tested by the assessment of the translocation of nuclear factor kappa B (NFκB) in LPS-stimulated RAW264.7 mouse macrophage. The extract (40 µg/mL) significantly inhibited the translocation of NFκB in the LPS-stimulated RAW264.7 macrophages by 48.2%, whereas 40 µg/mL of 6-bromoindole and 6-bromoistain caused a 60.7% and 63.7% reduction in NFκB, respectively. These results identify simple brominated indoles as useful anti-inflammatory drug leads and support the development of extracts from the Australian muricid D. orbita, as a new potential natural remedy for the treatment of inflammation.

Nutrigenomics of ω-3 fatty acids: Regulators of the master transcription factors

It is well known that ω-3 long-chain polyunsaturated fatty acids (LC-PUFAs) control some key molecular cell mechanisms, resulting in a beneficial role in inflammatory diseases. Such mechanisms are complex and reflect the diversity of their functions, mainly as modulators of the dynamic properties of membranes, regulators of gene expression, and precursors of active mediators. The aim of this review is to summarize the state of the art of the effects and mechanisms by which ω-3 LC-PUFAs such as eicosapentaenoic acid (EPA, C22:5 ω-3) and docosahexaenoic acid (DHA, C22:6 ω-3) regulate different metabolic processes to maintain homeostasis. Thus, we describe some aspects of these fatty acids-from their structural function in cell membranes to their role as regulators of gene expression, mainly in lipid metabolism. However, further studies are required to elucidate these actions and to have a better understanding in regard to the beneficial effects of ω-3 LC-PUFAs in the pathogenesis of several diseases as well as their functions as nutrients with protective action to avoid or delay development of these diseases. Furthermore, it is necessary to highlight the lack of comprehensive studies including nutritional, biochemical, genetic, and immune aspects to identify specific molecular mechanisms involved in the beneficial effects of consumption of DHA (C22:6 ω-3) and EPA (C22:5 ω-3) and their metabolic derivatives on health promotion.

A Study of the Differential Effects of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) on Gene Expression Profiles of Stimulated Thp-1 Macrophages

Background: An appropriate intake of omega-3 (n-3) fatty acids (FAs) such as eicosapentaenoic and docosahexaenoic acid (EPA/DHA) from marine sources is known to have anti-inflammatory effects. However, molecular mechanisms underlying their beneficial effects on health are not fully understood. The aim of the present study was to characterize gene expression profiles of THP-1 macrophages, incubated in either EPA or DHA and stimulated with lipopolysaccharide (LPS), a pro-inflammatory agent. Methods: THP-1 macrophages were incubated into 10, 50 and 75 µM of EPA or DHA for 24 h, and 100 nM of LPS was added to the culture media for 18 h. Total mRNA was extracted and gene expression examined by microarray analysis using Illumina Human HT-12 expression beadchips (Illumina). Results: Pathway analysis revealed that EPA and DHA regulate genes involved in cell cycle regulation, apoptosis, immune response and inflammation, oxidative stress and cancer pathways in a differential and dose-dependent manner. Conclusions: EPA and DHA appear to exert differential effects on gene expression in THP-1 macrophages. Specific effects of n-3 FAs on gene expression levels are also dose-dependent.

Dietary vegetable oil suppressed non-specific immunity and liver antioxidant capacity but induced inflammatory response in Japanese sea bass (Lateolabrax japonicus)

High percentage of dietary vegetable oil (VO) induced negative effects on immunity in numerous fish species. The present study was conducted to investigate whether VO could exert anti-immunological effects by regulating non-specific immunity, liver antioxidant capacity and nuclear factor kappa beta (NF-κB) signaling in Japanese sea bass (Lateolabrax japonicus). Three iso-nitrogenous and iso-lipid diets were formulated by replacing 0% (FO, the control), 50% (FV) and 100% (VO) of fish oil with vegetable oil. Each diet was randomly fed to triplicate groups of fish for 10 weeks. Results showed that the alternative complement pathway (ACP) activity and the disease resistance were significantly lower in fish fed VO diets compared with the control group (P < 0.05). Liver superoxide dismutase (SOD), catalase (CAT) and glutathion peroxidase (GPx) enzyme activities, as well as total antioxidant capacity (T-AOC) significantly decreased in fish fed VO diets (P < 0.05). Meanwhile, significantly low level of liver SOD1 and CAT mRNA, nuclear factor erythroid 2-related factor 2 (Nrf2) of both mRNA and protein were observed in fish fed VO diets when compared with fish fed FO diets (P < 0.05). However, the transcription level of TNFα and IL1β was significantly higher in the liver of fish fed VO diets, which might be attributed to the activation of NF-κB signaling pathway since the protein expression of p65, one of the key members of NF-κB family, was significantly increased (P < 0.05). These results suggested that dietary VO could lower the ACP activity, disease resistance and liver antioxidant capacity, but it could also exacerbate inflammatory response by activating NF-κB signaling pathway in Japanese sea bass.

The Effects of Immediate Enteral Feeding with a Formula Containing High Levels of ω-3 Fatty Acids in Patients After Surgery for Esophageal Cancer

BACKGROUND

We investigated whether supplementation of enteral nutrition (EN) with omega-3 polyunsaturated acids (PUFAs) affected platelet aggregation, coagulation activity, and inflammatory response in the early stages after esophageal cancer surgery.

METHODS

Twenty-eight patients with esophageal cancer who underwent the same surgical procedure were selected for this study. All patients received EN, which was started immediately after the operation and was increased to a maximum volume of 1500 ml/day by the third postoperative day (POD). Eleven patients received a conventional EN formula (Ensure Liquid), while the remaining 17 patients received a different formula rich in omega-3 PUFAs (Racol [RAC]). Several markers of coagulation and fibrinolysis were determined in POD 2, while the concentrations of interleukin (IL)-6, IL-8, 6-keto-PGF1alpha and thromboxane B2 were determined on PODs 1, 3, and 5.

RESULTS

A total of 27 patients completed the study, 11 in the Ensure Liquid group and 16 in the RAC group. Administration of RAC significantly inhibited the postoperative decrease in platelet count. The level of D-dimer was attenuated significantly in the RAC group. Plasma IL-8 levels were decreased significantly in the RAC group on PODs 1 and 3. The anti-inflammatory effects of omega-3 PUFAs were confirmed by the clinical findings of lower body temperature. The plasma concentration of 6-keto-PFG1alpha also tended to decrease in the RAC group with a significant difference on POD 5.

CONCLUSIONS

Early EN with a large amount of omega-3 PUFAs in reduced platelet aggregation, coagulation activity, and cytokine production. All these effects would be expected to be beneficial in patients following esophageal cancer surgery. The clinical significance of the changes in eicosanoid production remains to be established.

Is There a Role for Diet in the Therapy of Rheumatoid Arthritis?

Patients with rheumatoid arthritis (RA) often inquire about dietary interventions to improve RA symptoms. Although the majority of studies of diet and RA were published prior to the start of the twenty-first century, this review discusses the evidence for a relationship between diet, in particular omega-3 fatty acid supplements, vitamin D supplements, alcohol, and the Mediterranean diet and RA disease activity. We review possible mechanisms by which these dietary intakes may affect RA disease activity. Given the complexity of studying the relationship between diet and RA disease activity, we highlight areas deserving further study before specific recommendations can be made to RA patients.

Curcumin and long-chain Omega-3 polyunsaturated fatty acids for Prevention of type 2 Diabetes (COP-D): study protocol for a randomised controlled trial

Background

Lifestyle interventions, including increase in physical activity and dietary counselling, have shown the ability to prevent type 2 diabetes (T2D) in high-risk state individuals, but the prevalence is still skyrocketing in Australia, in line with global prevalence. Currently, no medicines are approved by the Therapeutic Goods Administration in Australia for the management of prediabetes. Therefore, there is a need of developing a safer, biologically efficacious and cost-effective alternative for delaying the transition of individual health state from prediabetes into T2D. In the current trial we propose to evaluate the effects of curcumin and/or long-chain omega-3 polyunsaturated fatty acids on improving glycosylated haemoglobin as a primary outcome, along with secondary outcomes of glycaemic indices, lipid profile and inflammatory parameters.

Methods/design

Eighty individuals diagnosed with prediabetes, aged between 30 and 70 years, will be randomly assigned to double placebo, curcumin alone, fish oil alone or double active groups according to a computer-generated randomisation sequence for 12 weeks. At baseline and post-intervention visits participants will be asked to provide blood samples and undergo body composition measurements. A blood sample is used for estimating glycaemic profiles, lipid profiles and inflammatory parameters (C-reactive protein, whole blood cell count, adiponectin, leptin, interleukin-6). The interim visit includes review on compliance with supplements based on capsule log and capsule count, adverse events and anthropometric measurements. In addition to these procedures, participants provide self-reported questionnaires on dietary intake (using a 3-day food record), a physical activity questionnaire and medical history.

Discussion

This trial aims to determine whether curcumin and/or long-chain omega-3 polyunsaturated fatty acids affect surrogate markers of glycaemic control which is relevant to delaying T2D. To date 38 participants completed the trial. No changes have been made to the clinical protocol post recruitment. If successful, this trial will provide considerable evidence for performing a larger trial to investigate whether this combination can be administered for preventing or delaying the onset of T2D in high-risk individuals.

Trial registration

ACTRN12615000559516, registered on 29 May 2015).

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1702-9) contains supplementary material, which is available to authorized users.

Diet and Inflammation in Alzheimer's Disease and Related Chronic Diseases: A Review

Inflammation is one of the pathological features of the neurodegenerative disease, Alzheimer's disease (AD). A number of additional disorders are likewise associated with a state of chronic inflammation, including obesity, cardiovascular disease, and type-2 diabetes, which are themselves risk factors for AD. Dietary components have been shown to modify the inflammatory process at several steps of the inflammatory pathway. This review aims to evaluate the published literature on the effect of consumption of pro- or anti-inflammatory dietary constituents on the severity of both AD pathology and related chronic diseases, concentrating on the dietary constituents of flavonoids, spices, and fats. Diet-based anti-inflammatory components could lead to the development of potent novel anti-inflammatory compounds for a range of diseases. However, further work is required to fully characterize the therapeutic potential of such compounds, including gaining an understanding of dose-dependent relationships and limiting factors to effectiveness. Nutritional interventions utilizing anti-inflammatory foods may prove to be a valuable asset in not only delaying or preventing the development of age-related neurodegenerative diseases such as AD, but also treating pre-existing conditions including type-2 diabetes, cardiovascular disease, and obesity.

Microbiota and chronic inflammatory arthritis: an interwoven link

BACKGROUND

Only recently, the scientific community gained insights on the importance of the intestinal resident flora for the host's health and disease. Gut microbiota in fact plays a crucial role in modulating innate and acquired immune responses and thus interferes with the fragile balance inflammation versus tolerance.

MAIN BODY

Correlations between gut bacteria composition and the severity of inflammation have been studied in inflammatory bowel diseases. More recently similar alterations in the gut microbiota have been reported in patients with spondyloarthritis, whereas in rheumatoid arthritis an accumulating body of evidence evokes a pathogenic role for the altered oral microbiota in disease development and course. In the context of dysbiosis it is also important to remember that different environmental factors like stress, smoke and dietary components can induce strong bacterial changes and consequent exposure of the intestinal epithelium to a variety of different metabolites, many of which have an unknown function. In this perspective, and in complex disorders like autoimmune diseases, not only the genetic makeup, sex and immunologic context of the individual but also the structure of his microbial community should be taken into account.

CONCLUSIONS

Here we provide a review of the role of the microbiota in the onset, severity and progression of chronic inflammatory arthritis as well as its impact on the therapeutic management of these patients. Furthermore we point-out the complex interwoven link between gut-joint-brain and immune system by reviewing the most recent data on the literature on the importance of environmental factors such as diet, smoke and stress.

Concentration and ratio of essential fatty acids influences the inflammatory response in lipopolysaccharide challenged mice

The goal of this study was to evaluate the role of both the % of dietary, 18-carbon PUFA (2.5%, 5% and 10%) and the n-6:n-3 ratio (1:1, 10:1 and 20:1) on the acute inflammatory response. Mice were fed diets for 8 weeks and injected intraperitoneally with LPS to induce acute inflammation. After 24h mice were sacrificed and plasma cytokines measured. Diets significantly affected the erythrocyte PUFA composition and the effect of PUFA ratio was more prominent than of PUFA concentration. The % dietary PUFA affected feed efficiency (p<0.05) and there was a PUFA×ratio interaction with body fat (p<0.01). In mice fed high %kcal from PUFA, those given a low n-6:n-3 ratio had more body fat than those fed a high ratio. Of the twelve cytokines measured, eleven were significantly affected by the % PUFA (p<0.05), whereas five were affected by the ratio (p<0.05). For seven cytokines, there was a significant PUFA×ratio interaction according to a two way ANOVA (p<0.05). These data indicate that dietary polyunsaturated fatty acids can affect LPS induced-inflammation.

Role of Omega-3 Fatty Acid Supplementation in Inflammation and Malignancy

Omega-3 fatty acids (FAs), which include eicosapentaenoic acid (EPA) and docosahexaenoic acid, are found in fish oils and have long been investigated as components of therapy for various disease states. Population studies initially revealed the cardioprotective and anti-inflammatory effects of omega-3 FAs and EPA, with subsequent clinical studies supporting the therapeutic role of omega-3 FAs in cardiovascular and chronic inflammatory conditions. Prospective randomized placebo-controlled trials have also demonstrated the utility of omega-3 FA supplementation in malignancy and cancer cachexia. In recent years, in vitro and animal studies have elucidated some of the mechanistic explanations underlying the wide range of biological effects produced by omega-3 FAs and EPA, including their antiproliferative and anticachectic actions in malignancy. In this review, the authors discuss the recent progress made with omega-3 FAs, focusing on the advances in mechanistic understanding and the results of clinical trials.

The importance of n-6/n-3 fatty acids ratio in the major depressive disorder

This review aims to clarify the relation between the ratio of omega-6 to omega-3 fatty acids and the development of depression. It is explained how these fatty acids are involved in the production of eicosanoids and how these fatty acids can affect the membrane fluidity, by their incorporation into membrane phospholipids. In addition, it is described how omega-3 derivatives are shown to regulate gene transcription. In view of the pathophysiology of depression, the mechanisms of how an altered ratio of omega-6 to omega-3 could be involved in depression are discussed. Possible mechanisms could include an increased production of pro-inflammatory cytokines, which can activate the HPA axis and a changed membrane fluidity, which potentially affects membrane bound enzymes, ion channels, receptor activity and neurotransmitter binding. In view of clinical trials, it is also discussed whether omega-3 supplementation could have a beneficial effect in the treatment of depressive patient. There are strong indications that an increased ratio of membrane omega-6 to omega-3 is involved in the pathogenesis of depression and so far, omega-3 supplementation has shown positive effects in clinical trials.

Effect of n-3 fatty acids on the expression of inflammatory genes in THP-1 macrophages

Background

Uncontrolled inflammation participates in the development of inflammatory diseases. Beneficial effects of polyunsaturated fatty acids belonging to the n-3 family such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on inflammation have been reported.

The present study investigates the basal effects of EPA, DHA and a mixture EPA + DHA on the expression of 10 genes (AKT1, MAPK, NFKB, TNFA, IL1Β, MCP1, ALOX5, PTGS2, MGST1and NOS2) related to inflammation in unstimulated cultured THP1 macrophages. Cells were incubated for 24 h with n-3 PUFAs (50 μM and 10 μM EPA, DHA, EPA + DHA). Expression levels of inflammatory genes were analyzed by real-time PCR.

Results

50 μM, 10 μM EPA and 50 μM EPA + DHA decreased the expression of genes involved in the NF-κB pathway (MAPK, AKT1, and NFKB). Treatment with 50 μM, 10 μM EPA, 50 μM DHA and EPA + DHA decreased expression levels of cytokines genes IL1Β and MCP1. TNFA expression was decreased by 50 μM, 10 μM of EPA, DHA and with 50 μM EPA + DHA. Two genes involved in the fatty acid metabolism (PTGS2 and ALOX5) were also modulated by the n-3 FAs. 50 μM of DHA and EPA + DHA inhibited PTGS2 expression when the two concentrations of EPA, 50 μM DHA and EPA + DHA inhibited ALOX5 expression. Finally, the effects of n-3 FAs were studied among genes involved in the oxidative stress. 50 μM of each fatty acid increased MGST1 expression. Both concentration of EPA and 50 μM DHA decreased NOS2 expression.

Conclusion

EPA seems to be more effective than DHA and EPA + DHA in modulating expression levels of selected inflammatory genes. The concentration of 50 μM was globally more effective than 10 μM.

Omega-3 fatty acids as an adjunct for periodontal therapy-a review

OBJECTIVES

The aim of this article is to present an overview of omega-3 fatty acids, their anti-inflammatory properties and potential use as an adjunct for periodontal therapy.

MATERIALS AND METHODS

A general literature search was conducted to provide an overview of omega-3 fatty acids, their metabolism and anti-inflammatory properties. A more specific literature search of PubMed and EMBASE was conducted to identify articles dealing studies investigating the effects of omega-3 fatty acids in the treatment of periodontitis in animals and humans and included cross-sectional, longitudinal and intervention designs.

RESULTS

To date, there is good emerging evidence that dietary supplementation with fish oil may be of some benefit and this is enhanced if combined with aspirin. All clinical intervention studies to date have been on small sample sizes, and this indicates there is need for larger and more robust clinical trials to verify these initial findings.

CONCLUSIONS

Dietary supplementation with fish oil could be a cost-effective adjunctive therapy to the management of periodontal disease.

CLINICAL RELEVANCE

The host modulatory properties of omega-3 fatty acids warrant further assessment of their use as an adjunct in the management of periodontitis.

n-3 Polyunsaturated Fatty Acids Improve Inflammation via Inhibiting Sphingosine Kinase 1 in a Rat Model of Parenteral Nutrition and CLP-Induced Sepsis

The sphingosine kinase 1 (SphK1)/sphingosine-1-phosphate (S1P) pathway plays a key role in inflammation. Parenteral nutrition containing n-3 polyunsaturated fatty acids (n-3 PUFA) may regulate inflammatory reactions. The aim of this study is to determine whether n-3 PUFA may improve inflammatory responses by neutralizing SphK1 signaling. Rat models of parenteral nutrition, cecal ligation and puncture (CLP)-induced sepsis were generated. Male Sprague-Dawley rats were operated for CLP on day 2 after venous catheterization. The rats were randomized to receive normal saline (NS; n = 20), parenteral nutrition (PN; n = 20), or PN + fish oil (FO; n = 20) for 5 days. The daily intake of fish oil (1.25-2.82 g EPA and 1.44-3.09 g DHA per 100 ml) in the FO group was approximately 1.8 g/kg body weight/day. Rats in the control group (n = 10) were subjected to sham operation and received a chow diet. Spleen tissues were collected for SphK1 and S1P receptor expression analysis. Our data showed that n-3 PUFA ameliorated the survival rate. SphK1 expression and its enzymatic activity were significantly upregulated in sepsis rats. Furthermore, mRNA and protein levels of S1PR3, but not S1PR1, were also facilitated after CLP. However, PN + FO dramatically decreased SphK1 mRNA level and its enzymatic activity. S1PR3 expression was also attenuated by FO addition. In conclusion, the anti-inflammatory effect of n-3 PUFA may be linked to the inhibition of the SphK1/S1P pathway in a rat model of parenteral nutrition and CLP-induced sepsis.

Resolvin E1 normalizes contractility, Ca2+ sensitivity and smooth muscle cell migration rate in TNF-α- and IL-6-pretreated human pulmonary arteries

Pulmonary hypertension (PH) is a rare disease in which pathophysiology is characterized by an increase in proinflammatory mediators, chronic endothelial dysfunctions, and a high migration rate of smooth muscle cells (SMC). Over the course of the last decade, various treatments have been proposed to relax the pulmonary arteries, none of which have been effective in resolving PH. Our hypothesis is that artery-relaxing drugs are not the long-term solution, but rather the inhibition of tissue inflammation, which underlies human pulmonary artery (HPA) dysfunctions that lead to abnormal vasoconstriction. The goal of the present study was to assess the anti-inflammatory effects of resolvin E1 (RvE1) with concomitant effects on SMC migration and on HPA reactivity. The role and mode of action of RvE1 and its precursor, monoacylglyceride eicosapentaenoic acid were assessed on HPA under proinflammatory conditions, involving a combined pretreatment with 10 ng/ml TNF-α and 10 ng/ml IL-6. Our results show that TNF-α and IL-6 treatment induced hyperreactivity and Ca2+ hypersensitivity in response to pharmaco-mechanical stimuli, including 80 mM KCl, 1 μM phorbol 12–13-dibutyrate, and 30 nM U-46619. Furthermore, the proinflammatory treatment increased the migration rate of SMC isolated from HPA. The phosphorylation level of regulatory contractile proteins (CPI-17, MYPT-1), and proinflammatory signaling pathways (c-Fos, c-Jun, NF-κB) were also significantly increased compared with control conditions. Conversely, 300 nM RvE1 was able to normalize all of the above abnormal events triggered by proinflammation. In conclusion, RvE1 can resolve human arterial hyperreactivity via the resolution of inflammatory markers.

Eicosapentaenoic acid prevents TCDD-induced oxidative stress and inflammatory response by modulating MAP kinases and redox-sensitive transcription factors

BACKGROUND AND PURPOSE

Oxidative stress and subsequent activation of inflammatory responses is a widely accepted consequence of exposure to environmental toxins. TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), a well-known environmental toxin, exerts its toxicity through many signalling mechanisms, with liver being the principal organ affected. However, an effective antidote to TCDD-induced toxicity is unknown. The present study evaluated the effect of eicosapentaenoic acid (EPA), an n3 fatty acid, on TCDD-induced toxicity.

EXPERIMENTAL APPROACH

In cultures of HepG2 cells, the EPA/AA ratio was determined using gas chromatography, oxidative stress and inflammatory responses through reactive oxygen species (ROS) levels, antioxidant status, [Ca(2+) ]i , nuclear migration of two redox-sensitive transcription factors, NF-κB p65 and Nrf-2, expression of MAP kinase (p-Erk, p-p38), NF-κB p65, COX-2 and Nrf-2. Cellular changes in ΔΨm, acidic vesicular organelle formation, cell cycle analysis and scanning electron microscopy analysis were performed.

KEY RESULTS

EPA offered significant cytoprotection by increasing EPA/AA ratios in cell membranes, inhibiting ROS generation, enhancing antioxidant status and modulating nuclear translocation of redox-sensitive transcription factors (NF-κB p65 and Nrf-2) and expression of NF-κB p65, COX-2 and Nrf-2. Furthermore, TCDD-induced upstream events of MAPK phosphorylation, the increase in [Ca(2+) ]i levels and cell surface changes in microvilli were significantly inhibited by EPA. EPA treatment maintained ΔΨm and prevented formation of acidic vesicular organelles.

CONCLUSION AND IMPLICATIONS

The present study demonstrates for the first time some underlying molecular mechanisms of cytoprotection exerted by EPA against TCDD-induced oxidative stress and inflammatory responses.