Relative levels of dietary EPA and DHA impact gastric oxidation and essential fatty acid uptake

A randomized double-blind trial to measure the absorption characteristics of eicosapentaenoic acid and docosahexaenoic acid rich oil blend with natural lipid-based delivery system

A randomized, double-blinded trial with 65 subjects was conducted to compare the pharmacokinetics between PhytoMarineCelle (PM) that consists of eicosapentaenoic acid and docosahexaenoic acid (EPA + DHA) plus a self-emulsifying drug delivery system (SEDDS), and a standard EPA + DHA ethyl ester (SEE) that does not contain SEDDS. PM showed 1.6-fold greater plasma area under the curve (AUC) than SEE at 300 mg, although no significant difference was observed. PM showed a 3.1 and 3.2-fold (p < 0.05) greater plasma AUC than SEE at 500 mg and 1000 mg respectively. The concentration max (Cmax) of EPA + DHA did not change between PM and SEE at 300 mg. Cmax of PM was twofold greater than SEE at 500 mg and 1000 mg respectively. The Cmax of EPA + DHA achieved significant difference (p < 0.05) only with the 500 mg dose. The PM formulation increased the bioavailability of EPA + DHA by threefold compared to SEE at 500 and 1000 mg.

Evaluation of the Metabolite Profile of Fish Oil Omega-3 Fatty Acids (n-3 FAs) in Micellar and Enteric-Coated Forms-A Randomized, Cross-Over Human Study

This study evaluated the differences in the metabolite profile of three n-3 FA fish oil formulations in 12 healthy participants: (1) standard softgels (STD) providing 600 mg n-3 FA; (2) enteric-coated softgels (ENT) providing 600 mg n-3 FA; (3) a new micellar formulation (LMF) providing 374 mg n-3 FA. The pharmacokinetics (PKs), such as the area under the plot of plasma concentration (AUC), and the peak blood concentration (Cmax) of the different FA metabolites including HDHAs, HETEs, HEPEs, RvD1, RvD5, RvE1, and RvE2, were determined over a total period of 24 h. Blood concentrations of EPA (26,920.0 ± 10,021.0 ng/mL·h) were significantly higher with respect to AUC0-24 following LMF treatment vs STD and ENT; when measured incrementally, blood concentrations of total n-3 FAs (EPA/DHA/DPA3) up to 11 times higher were observed for LMF vs STD (iAUC 0-24: 16,150.0 ± 5454.0 vs 1498.9 ± 443.0; p ≤ 0.0001). Significant differences in n-3 metabolites including oxylipins were found between STD and LMF with respect to 12-HEPE, 9-HEPE, 12-HETE, and RvD1; 9-HEPE levels were significantly higher following the STD vs. ENT treatment. Furthermore, within the scope of this study, changes in blood lipid levels (i.e., cholesterol, triglycerides, LDL, and HDL) were monitored in participants for up to 120 h post-treatment; a significant decrease in serum triglycerides was detected in participants (~20%) following the LMF treatment; no significant deviations from the baseline were detected for all the other lipid biomarkers in any of the treatment groups. Despite a lower administered dose, LMF provided higher blood concentrations of n-3 FAs and certain anti-inflammatory n-3 metabolites in human participants-potentially leading to better health outcomes.

A Randomized, Open-Label, Single-Dose, Crossover Study of the Comparative Bioavailability of EPA and DHA in a Novel Liquid Crystalline Nanoparticle-Based Formulation of ω-3 Acid Ethyl Ester Versus Omacor® Soft Capsule among Healthy Adults

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are well known for their capacity to lower triglyceride levels, but the clinical effectiveness is hindered by limited bioavailability and patient adherence. To address this challenge, we introduce a novel liquid crystalline nanoparticle-based formulation, the innovative medicine and drug delivery (IMD)-Omega soft capsule (cap), designed to optimize the pharmacokinetics (PK) and safety of EPA and DHA. This randomized, open-label, crossover study engages a cohort of 24 healthy adult subjects, utilizing key PK parameters like Cmax, AUC, Tmax, t½, and Ke to conduct a comprehensive evaluation. The trial compares the performance of the IMD-Omega soft cap with the well-established Omacor® soft cap. The IMD-Omega soft cap exhibited an impressive 110% increase in bioavailability for EPA and a remarkable 134% surge for DHA in comparison to the Omacor® soft cap over a span of 72 h. The key success can be attributed to the innovative liquid crystalline nanoparticle design, bolstering the dissolution and permeability of these essential fatty acids. Intriguingly, intra-participant variability for AUC0-72 h and Cmax were calculated at 45.04% and 34.26%, respectively. It is noteworthy that the parameters of Tmax for EPA (≈6.00 h) and DHA (≈5.00 h), t½ for both EPA and DHA ≈ 30-40 h, and Kel around 0.18-0.22 h-1 for EPA and ≈0.008-0.02 h-1 for DHA, displayed comparability between the IMD-Omega and Omacor® formulations. Encouragingly, the IMD-Omega soft cap showed excellent tolerability. The promise of optimized patient compliance and reduced dosages adds further weight to its potential significance.

Lipid emulsion structure, digestion behavior, physiology, and health: a scoping review and future directions

Research investigating the effects of the food matrix on health is needed to untangle many unresolved questions in nutritional science. Emulsion structure plays a fundamental role in this inquiry; however, the effects of oil-in-water emulsion structure on broad metabolic, physiological, and health-related outcomes have not been comprehensively reviewed. This systematic scoping review targets this gap and examines methodological considerations for the field of relating food structure and health. MEDLINE, Web of Science, and CAB Direct were searched from inception to December 2022, returning 3106 articles, 52 of which were eligible for inclusion. Many investigated emulsion lipid droplet size and/or gastric colloidal stability and their relation to postprandial weight-loss-related outcomes. The present review also identifies numerous novel relationships between emulsion structures and health-related outcomes. "Omics" endpoints present an exciting avenue for more comprehensive analysis in this area, yet interpretation remains difficult. Identifying valid surrogate biomarkers for long-term outcomes and disease risk will be a turning point for food structure research, leading to breakthroughs in the pace and utility of research that generates advancements in health. The review's findings and recommendations aim to support new hypotheses, future trial design, and evidence-based emulsion design for improved health and well-being.

Effects of Marine Bioactive Compounds on Gut Ecology Based on In Vitro Digestion and Colonic Fermentation Models

Digestion and the absorption of food compounds are necessary steps before nutrients can exert a role in human health. The absorption and utilization of nutrients in the diet is an extremely complex dynamic process. Accurately grasping the digestion and absorption mechanisms of different nutrients or bioactive compounds can provide a better understanding regarding the relationship between health and nutrition. Several in vitro models for simulating human gastrointestinal digestion and colonic fermentation have been established to obtain more accurate data for further understanding of the metabolism of dietary components. Marine media is rich in a wide variety of nutrients that are essential for humans and is gaining increased attention as a research topic. This review summarizes some of the most explored in vitro digestion and colonic fermentation models. It also summarizes the research progress on the digestion and absorption of nutrients and bioactive compounds from marine substrates when subjected to these in vitro models. Additionally, an overview of the changes imparted by the digestion process on these bioactive compounds is provided, in order to support those marine resources that can be utilized for developing new healthy foods.

Fat Oxidation of Fatty Fish vs. Meat Meal Diets Under in vitro Standardized Semi-Dynamic Gastric Digestion

Meat and fish are introduced into the diet as a source of protein, but these muscle foods present different fatty acid (FA) compositions and different lipid stabilities. Fatty fish is expected to oxidize due to its higher content of polyunsaturated FA (PUFA), whereas the higher heme-Fe content of red meat will also affect lipid stability. Combining other food ingredients within a meal also influences lipid oxidation, which will not stop after meals intake. This is due to the acidic environment of the stomach together with the presence of metallic ions, a process that is scarcely understood. The goal of this study was to evaluate the oxidation of fatty fish vs. meat meal diets under in vitro standardized semi-dynamic gastric conditions and FA release from the stomach to the duodenum. Meal diets composed by 25% beef meal (BM) or fatty fish meal (FM), 25% fried potatoes, and 50% sugar soft drink were prepared. Proximate composition, FA and amino acid profiles, and meals quality indices were evaluated. Their differences in composition led to different total gastric digestion time of 242.74 (BM) and 175.20 (FM) minutes. Using the INFOGEST semi-dynamic gastric model, 4 gastric emptying (GE) were simulated in both meals. In each GE, FA profile and lipid oxidation products (LOPs) formation were assessed. As a result, more than 50% FA release to the duodenum occurred in GE1, whose percentage decreased with the time of digestion. FM exhibited the highest LOPs formation, which corroborates the high peroxidizability index measured for this meal diet. Higher LOPs formation occurred in the later GEs, which released less FA. This suggests that higher times of residence in the stomach increase FA oxidation. This study shows a higher formation of LOPs during digestion of FM using a whole meal approach. These results relate to its richness in PUFAs compared to BM. Despite higher LOPs formation, FM digests that reached duodenum still contain higher content of unoxidized PUFAs compared with BM and a desirable ω3/ω6 PUFAs ratio of ~0.43. LOPs formation in PUFA-rich meals could be reduced if those meals have a low caloric value, avoiding large times of residence in the stomach and consequently high levels of oxidation.

The Role of Dietary and Microbial Fatty Acids in the Control of Inflammation in Neonatal Piglets

Simple Summary

The maturation of the gut is a specific and very dynamic process in new-born piglets. Consequently, piglet’s gut is very susceptible to disturbances, especially in stressful periods of life, such as weaning, when the gut lining often becomes inflamed and leaky. Dietary fatty acids (FA) do not only serve as source of energy and essential FA, but they are important precursors for bioactive lipid mediators, which modulate inflammatory signalling in the body. The current review summarizes results on dietary sources of FA for piglets, the signalling cascades, bioactivities, the necessity to consider the autoxidation potential of polyunsaturated FA and the area of microbially produced long-chain FA. That said, porcine milk is high in fat, whereby the milk FA composition partly depends on the dietary FA composition of the sow. Therefore, manipulation of the sow diet is an efficient tool to increase the piglet’s intake of specific FA, e.g., n-3 polyunsaturated FA which show anti-inflammatory activity and may support intestinal integrity and functioning in the growing animal.

Abstract

Excessive inflammation and a reduced gut mucosal barrier are major causes for gut dysfunction in piglets. The fatty acid (FA) composition of the membrane lipids is crucial for mediating inflammatory signalling and is largely determined by their dietary intake. Porcine colostrum and milk are the major sources of fat in neonatal piglets. Both are rich in fat, demonstrating the dependence of the young metabolism from fat and providing the young organism with the optimum profile of lipids for growth and development. The manipulation of sow’s dietary polyunsaturated FA (PUFA) intake has been shown to be an efficient strategy to increase the transfer of specific FAs to the piglet for incorporation in enteric tissues and cell membranes. n-3 PUFAs, especially seems to be beneficial for the immune response and gut epithelial barrier function, supporting the piglet’s enteric defences in situations of increased stress such as weaning. Little is known about microbial lipid mediators and their role in gut barrier function and inhibition of inflammation in neonatal piglets. The present review summarizes the current knowledge of lipid nutrition in new-born piglets, comparing the FA ingestion from milk and plant-based lipid sources and touching the areas of host lipid signalling, inflammatory signalling and microbially derived FAs.

Impact of Dietary Lipids on the Reverse Cholesterol Transport: What We Learned from Animal Studies

Reverse cholesterol transport (RCT) is a physiological mechanism protecting cells from an excessive accumulation of cholesterol. When this process begins in vascular macrophages, it acquires antiatherogenic properties, as has been widely demonstrated in animal models. Dietary lipids, despite representing a fundamental source of energy and exerting multiple biological functions, may induce detrimental effects on cardiovascular health. In the present review we summarize the current knowledge on the mechanisms of action of the most relevant classes of dietary lipids, such as fatty acids, sterols and liposoluble vitamins, with effects on different steps of RCT. We also provide a critical analysis of data obtained from experimental models which can serve as a valuable tool to clarify the effects of dietary lipids on cardiovascular disease.

Polyphenols and Fish Oils for Improving Metabolic Health: A Revision of the Recent Evidence for Their Combined Nutraceutical Effects

Polyphenols and omega-3 polyunsaturated fatty acids from fish oils, i.e., eicosapentaenoic and docosahexaenoic acids, are well-recognized nutraceuticals, and their single antioxidant and anti-inflammatory properties have been demonstrated in several studies found in the literature. It has been reported that the combination of these nutraceuticals can lead to three-fold increases in glutathione peroxidase activity, two-fold increases in plasma antioxidant capacity, decreases of 50-100% in lipid peroxidation, protein carbonylation, and urinary 8-isoprotanes, as well as 50-200% attenuation of common inflammation biomarkers, among other effects, as compared to their individual capacities. Therefore, the adequate combination of those bioactive food compounds and their single properties should offer a powerful tool for the design of successfully nutritional interventions for the prevention and palliation of a plethora of human metabolic diseases, frequently diet-induced, whose etiology and progression are characterized by redox homeostasis disturbances and a low-grade of chronic inflammation. However, the certain mechanisms behind their biological activities, in vivo interaction (both between them and other food compounds), and their optimal doses and consumption are not well-known yet. Therefore, we review here the recent evidence accumulated during the last decade about the cooperative action between polyphenols and fish oils against diet-related metabolic alterations, focusing on the mechanisms and pathways described and the effects reported. The final objective is to provide useful information for strategies for personalized nutrition based on these nutraceuticals.

Supplemental Xylooligosaccharide Modulates Intestinal Mucosal Barrier and Cecal Microbiota in Laying Hens Fed Oxidized Fish Oil

Our previous study indicated that dietary xylooligosaccharide (XOS) supplementation improved feed efficiency, ileal morphology, and nutrient digestibility in laying hens. The objective of this study was to evaluate the mitigative effects of XOS on intestinal mucosal barrier impairment and microbiota dysbiosis induced by oxidized fish oil (OFO) in laying hens. A total of 384 Hy-Line Brown layers at 50 weeks of age were randomly divided into four dietary treatments, including the diets supplemented with 20 g/kg of fresh fish oil (FFO group) or 20 g/kg of oxidized fish oil (OFO group), and the OFO diets with XOS addition at 200 mg/kg (OFO/XOS200 group) or 400 mg/kg (OFO/XOS400 group). Each treatment had eight replicates with 12 birds each. The OFO treatment decreased (P < 0.05) the production performance of birds from 7 to 12 weeks of the experiment, reduced (P < 0.05) ileal mucosal secretory immunoglobulin A (sIgA) content, and increased (P < 0.05) serum endotoxin concentration, as well as downregulated (P < 0.05) mRNA expression of claudin-1 (CLDN1) and claudin-5 (CLDN5) in the ileal mucosa at the end of the experiment. Dietary XOS addition (400 mg/kg) recovered (P < 0.05) these changes and further improved (P < 0.05) ileal villus height (VH) and the villus height-to-crypt depth ratio (VCR). In addition, OFO treatment altered cecal microbial composition of layers, and these alterations were probably involved in OFO-induced ileal mucosal impairment as causes or consequences. Supplemental XOS remodeled cecal microbiota of layers fed the OFO diet, characterized by an elevation in microbial richness and changes in microbial composition, including increases in Firmicutes, Ruminococcaceae, Verrucomicrobia (Akkermansia), Paraprevotella, Prevotella_9, and Oscillospira, along with a decrease in Erysipelatoclostridium. The increased abundance of Verrucomicrobia (Akkermansia) had positive correlations with the improved ileal VH and ileal mucosal expression of CLDN1. The abundance of Erysipelatoclostridium decreased by XOS addition was negatively associated with ileal VH, VCR, ileal mucosal sIgA content, and the relative expression of zonula occludens-2, CLDN1, and CLDN5. Collectively, supplemental XOS alleviated OFO-induced intestinal mucosal barrier dysfunction and performance impairment in laying hens, which could be at least partially attributed to the modulation of gut microbiota.

Protective Effect of Lacticaseibacillus casei CRL 431 Postbiotics on Mitochondrial Function and Oxidative Status in Rats with Aflatoxin B1-Induced Oxidative Stress

Studies have shown that the intracellular content of probiotic (postbiotics) has antioxidant properties, which can improve the antioxidant status in vivo. However, its absorption and mechanisms underlying the protective effects are still unknown. The antioxidant capacity of Lacticaseibacillus casei CRL431 (IC-431) postbiotics was determined after an in vitro simulated digestive process. Permeability of antioxidant constituents of IC-431 was determined by an ex vivo everted duodenum assay. Aflatoxin B₁-induced oxidative stress rat models were established and treated with IC-431; biomarkers of hepatic mitochondrial function and H₂O₂ levels, oxidative stress, and oxidative stress index (OSi) were examined. The antioxidant capacity of IC-431 (477 ± 45.25 μmol Trolox Equivalent/L) was reduced by exposure to the simulated digestive process. No difference (p > 0.05) was found among digested and the permeate fraction of IC-431. A protective effect was observed by significantly lower OSi and higher liver glutathione peroxidase and catalase activities. Lower H₂O₂ production, a higher degree of mitochondrial uncoupling, and lower mitochondrial respiration coefficient were also observed (p < 0.05). These results suggest that IC-431 antioxidant components permeate intestinal barriers to enter the bloodstream and regulate antioxidant status during AFB₁-induced oxidative stress by reducing hepatic mitochondrial dysfunction, thus enhancing antioxidant enzyme response.

In Vivo Digestion of Egg Products Enriched with DHA: Effect of the Food Matrix on DHA Bioavailability

The aim of the present study was to determine to what extent the food matrix could affect the release of docosahexaenoic acid (DHA) during digestion and its incorporation into systemic circulation. In this aim, three DHA-enriched egg products having the same composition but different structure were developed: omelet, hard-boiled egg, and mousse. Then, nine pigs fitted with T-shape cannulas at duodenal level and a jugular venous catheter were fed with the DHA-enriched egg products, and duodenal effluents and plasma were collected throughout the postprandial period. Results highlighted an undeniable effect of the food matrix on digestion parameters and DHA bioavailability. The transit of DHA and protein through the duodenum was faster after the ingestion of the mousse than after the ingestion of the omelet and hard-boiled egg. While most of the DHA and protein ingested under the form of mousse had already passed through the duodenum 4.5 h after its ingestion, significantly higher quantities were still present in the case of the omelet and hard-boiled egg. In terms of bioavailability, the omelet was the most efficient vector for delivering DHA into systemic circulation. It supplied 56% and 120% more DHA than the hard-boiled egg and the mousse, respectively.

Effect of Phospholipase A1 and High-Pressure Homogenization on the Stability, Toxicity, and Permeability of Egg Yolk/Fish Oil Emulsions

Enzymatic treatment of egg yolk with phospholipases can enhance its emulsifying properties and thermal stability. Additionally, a two-step process (primary and secondary homogenization) could form emulsions with better stability. Thus, in this study we used a split-split-plot in time design to assess the effect of enzymatic treatment, processing, and storage conditions on the encapsulation efficiency, stability, toxicity, and permeability of egg yolk/fish oil emulsions stored up to 10 days at 45 °C. Egg yolk solutions before and after treatment with phospholipase A₁ were used as carriers of fish oil containing ≥82% eicosapentaenoic and docosahexaenoic acids. Emulsions were formed by primary (24,000 rpm, 4 min) and secondary (200 MPa) homogenization. The combined effect of treatment with phospholipase A₁ and secondary homogenization resulted in emulsions with improved stability, increased the encapsulation efficiency of the carriers, and reduced the release of oil to the particle surface, resulting in lower formation of oxidation products. At the end of storage time, none of the emulsions were toxic to Caco-2 cells at a concentration of 75 μg/mL medium, while nonencapsulated fish oil reduced cell viability to 81%. Only eicosapentaenoic acid was detected in the basolateral side of Caco-2:HT29 monolayers, and its apparent permeability from nonencapsulated fish oil was significantly lower than that from emulsions.

Omega-3 Phospholipids from Krill Oil Enhance Intestinal Fatty Acid Oxidation More Effectively than Omega-3 Triacylglycerols in High-Fat Diet-Fed Obese Mice

Antisteatotic effects of omega-3 fatty acids (Omega-3) in obese rodents seem to vary depending on the lipid form of their administration. Whether these effects could reflect changes in intestinal metabolism is unknown. Here, we compare Omega-3-containing phospholipids (krill oil; ω3PL-H) and triacylglycerols (ω3TG) in terms of their effects on morphology, gene expression and fatty acid (FA) oxidation in the small intestine. Male C57BL/6N mice were fed for 8 weeks with a high-fat diet (HFD) alone or supplemented with 30 mg/g diet of ω3TG or ω3PL-H. Omega-3 index, reflecting the bioavailability of Omega-3, reached 12.5% and 7.5% in the ω3PL-H and ω3TG groups, respectively. Compared to HFD mice, ω3PL-H but not ω3TG animals had lower body weight gain (−40%), mesenteric adipose tissue (−43%), and hepatic lipid content (−64%). The highest number and expression level of regulated intestinal genes was observed in ω3PL-H mice. The expression of FA ω-oxidation genes was enhanced in both Omega-3-supplemented groups, but gene expression within the FA β-oxidation pathway and functional palmitate oxidation in the proximal ileum was significantly increased only in ω3PL-H mice. In conclusion, enhanced intestinal FA oxidation could contribute to the strong antisteatotic effects of Omega-3 when administered as phospholipids to dietary obese mice.

Environmental lipidomics: understanding the response of organisms and ecosystems to a changing world

BACKGROUND

Understanding the interaction between organisms and the environment is important for predicting and mitigating the effects of global phenomena such as climate change, and the fate, transport, and health effects of anthropogenic pollutants. By understanding organism and ecosystem responses to environmental stressors at the molecular level, mechanisms of toxicity and adaptation can be determined. This information has important implications in human and environmental health, engineering biotechnologies, and understanding the interaction between anthropogenic induced changes and the biosphere. One class of molecules with unique promise for environmental science are lipids; lipids are highly abundant and ubiquitous across nearly all organisms, and lipid profiles often change drastically in response to external stimuli. These changes allow organisms to maintain essential biological functions, for example, membrane fluidity, as they adapt to a changing climate and chemical environment. Lipidomics can help scientists understand the historical and present biofeedback processes in climate change and the biogeochemical processes affecting nutrient cycles. Lipids can also be used to understand how ecosystems respond to historical environmental changes with lipid signatures dating back to hundreds of millions of years, which can help predict similar changes in the future. In addition, lipids are direct targets of environmental stressors, for example, lipids are easily prone to oxidative damage, which occurs during exposure to most toxins.

AIM OF REVIEW

This is the first review to summarize the current efforts to comprehensively measure lipids to better understand the interaction between organisms and their environment. This review focuses on lipidomic applications in the arenas of environmental toxicology and exposure assessment, xenobiotic exposures and health (e.g., obesity), global climate change, and nutrient cycles. Moreover, this review summarizes the use of and the potential for lipidomics in engineering biotechnologies for the remediation of persistent compounds and biofuel production.

KEY SCIENTIFIC CONCEPT

With the preservation of certain lipids across millions of years and our ever-increasing understanding of their diverse biological roles, lipidomic-based approaches provide a unique utility to increase our understanding of the contemporary and historical interactions between organisms, ecosystems, and anthropogenically-induced environmental changes.

Intestinal bioavailability of n-3 long-chain polyunsaturated fatty acids influenced by the supramolecular form of phospholipids

This work aims at studying the bioavailability of n-3 long-chain polyunsaturated fatty acids carried by marine phospholipids, formulated in different supramolecular forms,i.e.oil-in-water emulsion and liposomes.

Lipidomic methodologies for biomarkers of chronic inflammation in nutritional research: ω-3 and ω-6 lipid mediators

The evolutionary history of hominins has been characterized by significant dietary changes, which include the introduction of meat eating, cooking, and the changes associated with plant and animal domestication. The Western pattern diet has been linked with the onset of chronic inflammation, and serious health problems including obesity, metabolic syndrome, and cardiovascular diseases. Diets enriched with ω-3 marine PUFAs have revealed additional improvements in health status associated to a reduction of proinflammatory ω-3 and ω-6 lipid mediators. Lipid mediators are produced from enzymatic and non-enzymatic oxidation of PUFAs. Interest in better understanding the occurrence of these metabolites has increased exponentially as a result of the growing evidence of their role on inflammatory processes, control of the immune system, cell signaling, onset of metabolic diseases, or even cancer. The scope of this review has been to highlight the recent findings on: a) the formation of lipid mediators and their role in different inflammatory and metabolic conditions, b) the direct use of lipid mediators as antiinflammatory drugs or the potential of new drugs as a new therapeutic option for the synthesis of antiinflammatory or resolving lipid mediators and c) the impact of nutritional interventions to modulate lipid mediators synthesis towards antiinflammatory conditions. In a second part, we have summarized methodological approaches (Lipidomics) for the accurate analysis of lipid mediators. Although several techniques have been used, most authors preferred the combination of SPE with LC-MS. Advantages and disadvantages of each method are herein addressed, as well as the main LC-MS difficulties and challenges for the establishment of new biomarkers and standardization of experimental designs, and finally to deepen the study of mechanisms involved on the inflammatory response.