Docosahexaenoic acid-rich algae oil supplementation in mothers of preterm infants is associated with a modification in breast milk oxylipins profile.

Oxylipins are derived from enzymatic and non-enzymatic oxidation of n-3 and n-6 long-chain polyunsaturated fatty acids. They are known to be involved in inflammatory processes. The aim of this study was to describe the breast milk oxylipin profile following a docosahexaenoic acid (DHA) supplementation of mothers of preterm infants. We examined the oxylipins profile in breast milk collected at day 14 post-delivery, of 40 mothers who delivered before 29 weeks of gestation and who were supplemented with either DHA-rich algae oil (S-DHA) or a placebo (PL). These mothers were selected from the MOBYDIck cohort (NCT02371460 registered on 25/05/2015 in ClinicalTrials.gov) according to the supplementation received (S-DHA vs. PL) and the DHA content quartiles as measured in breast milk (Low vs. High) to generate four study groups. Milk oxylipins, as ng/mL of milk, were analyzed by LC-MS/MS. Ten oxylipins derived from DHA were higher in the S-DHA-High group than the other three groups (P < 0.001). The 18-HEPE, was also higher in the S-DHA-High group (0.11 ± 0.01) compared to the other groups (P = 0.0001). Compared to the PL-Low group, there was a reduction in pro-inflammatory prostaglandins found in the S-DHA-High group with lower levels of prostaglandins PGF2α (0.21 ± 0.45 in the S-DHA-High group vs. 1.87 ± 0.44 in the PL-Low group, P = 0.03) and of PGE2 (0.33 ± 0.26 in the S-DHA-High group vs. 1.28 ± 0.25 in the PL-Low group, P = 0.04).In sum, the DHA supplementation was linked with a predominance of anti-inflammatory oxylipins in breast milk of mothers who delivered very preterm, like 17(S)-HDHA and 18-HEPE, precursors of D and E resolvins respectively. This was also accompanied with a lower level of pro-inflammatory prostaglandins.

Residual Solvents in Nanomedicine and Lipid-Based Drug Delivery Systems: a Case Study to Better Understand Processes.

PURPOSE: Complexities surrounding the manufacture and quality control of nanomedicines become increasingly apparent. This research article offers a case study to investigate how, at the laboratory scale, various stages of liposome and nanoparticle synthesis affect the amount of residual solvent found in the formulations. The objective is to bring insights on the reliability of each of these processes to provide final products which meet regulatory standards and facilitate identifying possible bottleneck early during the development process. METHODS: The residual solvent at various stages of preparation and purification was measured by headspace gas chromatography. Liposomes were prepared by two different methods with and without solvent. Polymer nanoparticles prepared via nanoprecipitation and purified by ultrafiltration were studied. The effects of purification by size exclusion chromatography and dialysis were also investigated. RESULTS: The complete removal of residual solvent requires processes which go beyond usual preparation methods. CONCLUSIONS: This work might prove valuable as a reference for scientists of different fields to compare their own practices and streamline the translation of nanomedicines into efficacious and safe drug products.

Studying the stability of polymer nanoparticles by size exclusion chromatography of radioactive polymers.

The properties of nanomedicines will influence how they can deliver drugs to patients reproducibly and effectively. For conventional pharmaceutical products, Chemistry, Manufacturing and Control (CMC) documents require monitoring stability and storage conditions. For nanomedicines, studying these important considerations is hindered by a lack of appropriate methods. In this paper, we show how combining radiolabelling with size exclusion chromatography, using a method called SERP (for Size Exclusion of Radioactive Polymers), can inform on the in vitro degradation of polymer nanoparticles. Using nanoparticles composed of biodegradable poly(lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA), we show that SERP is more sensitive than dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) to detect degradation. We also demonstrate that the properties of the polymer composition and the nature of the aqueous buffer affect nanoparticle degradation. Importantly, we show that minute changes in stability that cannot be detected by DLS and NTA impact the pharmacokinetic of nanoparticles injected in vivo. We believe that SERP might prove a valuable method to document and understand the pharmaceutical quality of polymer nanoparticles.

No benefit of vitamin D supplementation on muscle function and health-related quality of life in primary cardiovascular prevention patients with statin-associated muscle symptoms: A randomized controlled trial.

BACKGROUND: Statins are the leading lipid-lowering drugs, reducing blood cholesterol by controlling its synthesis. Side effects are linked to the use of statins, in particular statin-associated muscle symptoms (SAMS). Some data suggest that vitamin D supplementation could reduce SAMS. OBJECTIVE: The purpose of this study was to evaluate the potential benefits of vitamin D supplementation in a randomized controlled trial. METHODS: Men (n = 23) and women (n = 15) (50.5 ± 7.7 years [mean ± SD]) in primary cardiovascular prevention, self-reporting or not SAMS, were recruited. Following 2 months of statin withdrawal, patients were randomized to supplementation (vitamin D or placebo). After 1 month of supplementation, statins were reintroduced. Before and 2 months after drug reintroduction, muscle damage (creatine kinase and myoglobin) was measured. Force (F), endurance (E) and power (P) of the leg extensors (ext) and flexors (fle) and handgrip strength (FHG) were also measured with isokinetic and handheld dynamometers, respectively. The Short Form 36 Health Survey (SF-36) questionnaire and a visual analog scale (VAS) were administrated to assess participants' self-reported health-related quality of life and SAMS intensity, respectively. Repeated-measures analysis was used to investigate the effects of time, supplementation, and their interaction, according to the presence of SAMS. RESULTS: Despite no change for objective measures, subjective measures worsened after reintroduction of statins, independent of supplementation (VAS, SF-36 mental component score, all p < 0.05). However, no interaction between time and supplementation according to the presence of SAMS was observed for any variables. CONCLUSIONS: Vitamin D supplementation does not appear to mitigate SAMS.

Impact of statin withdrawal on perceived and objective muscle function.

BACKGROUND AND AIMS: Statin-associated muscle symptoms (SAMS) are frequently reported. Nevertheless, few data on objective measures of muscle function are available. Recent data suggesting an important nocebo effect with statin use could confound such effects. The objective was to assess if subjective and objective measures of muscle function improve after drug withdrawal in SAMS reporters. METHODS: Patients (59 men, 33 women, 50.3±9.6 yrs.) in primary cardiovascular prevention composed three cohorts: statin users with (SAMS, n = 61) or without symptoms (No SAMS, n = 15), and controls (n = 16) (registered at clinicaltrials.gov, NCT01493648). Force (F), endurance (E) and power (P) of the leg extensors (ext) and flexors (fle) and handgrip strength (Fhg) were measured using isokinetic and handheld dynamometers, respectively. A 10-point visual analogue scale (VAS) was used to self-assess SAMS intensity. Measures were taken before and after two months of withdrawal. RESULTS: Following withdrawal, repeated-measures analyses show improvements for the entire cohort in Eext, Efle, Ffle, Pext and Pfle (range +7.2 to +13.3%, all p≤0.02). Post-hoc analyses show these changes to occur notably in SAMS (+8.8 to +16.6%), concurrent with a decrease in subjective perception of effects in SAMS (VAS, from 5.09 to 1.85). Fhg was also improved in SAMS (+4.0 to +6.2%) when compared to No SAMS (-1.7 to -4.2%) (all p = 0.02). CONCLUSIONS: Whether suffering from "true" SAMS or nocebo, those who reported SAMS had modest but relevant improvements in muscle function concurrent with a decrease in subjective symptoms intensity after drug withdrawal. Greater attention by clinicians to muscle function in frail statin users appears warranted. TRIAL REGISTRATION: This study is registered in clinicaltrials.gov (NCT01493648).

Industrial and Ruminant Trans-Fatty Acids-Enriched Diets Differentially Modulate the Microbiome and Fecal Metabolites in C57BL/6 Mice.

Industrially originated trans-fatty acids (I-tFAs), such as elaidic acid (EA), and ruminant trans-fatty acids (R-tFAs), such as trans-palmitoleic acid (TPA), may have opposite effects on metabolic health. The objective was to compare the effects of consuming 2-3% I-tFA or R-tFA on the gut microbiome and fecal metabolite profile in mice after 7 and 28 days. Forty C57BL/6 mice were assigned to one of the four prepared formulations: lecithin nanovesicles, lecithin nanovesicles with EA or TPA, or water. Fecal samples and animals' weights were collected on days 0, 7, and 28. Fecal samples were used to determine gut microbiome profiles by 16S rRNA sequencing and metabolite concentrations by GC/MS. At 28 days, TPA intake decreased the abundance of Staphylococcus sp55 but increased Staphylococcus sp119. EA intake also increased the abundance of Staphylococcus sp119 but decreased Ruminococcaceae UCG-014, Lachnospiraceae, and Clostridium sensu stricto 1 at 28 days. Fecal short-chain fatty acids were increased after TPA while decreased after EA after 7 and 28 days. This study shows that TPA and EA modify the abundance of specific microbial taxa and fecal metabolite profiles in distinct ways.

Remodeling of lipid landscape in high fat fed very-long chain acyl-CoA dehydrogenase null mice favors pro-arrhythmic polyunsaturated fatty acids and their downstream metabolites.

Very-long chain acyl-CoA dehydrogenase (VLCAD) catalyzes the initial step of mitochondrial long chain (LC) fatty acid ß-oxidation (FAO). Inherited VLCAD deficiency (VLCADD) predisposes to neonatal arrhythmias whose pathophysiology is still not understood. We hypothesized that VLCADD results in global disruption of cardiac complex lipid homeostasis, which may set conditions predisposing to arrhythmia. To test this, we assessed the cardiac lipidome and related molecular markers in seven-month-old VLCAD-/- mice, which mimic to some extent the human cardiac phenotype. Mice were sacrificed in the fed or fasted state after receiving for two weeks a chow or a high-fat diet (HFD), the latter condition being known to worsen symptoms in human VLCADD. Compared to their littermate counterparts, HFD/fasted VLCAD-/- mouse hearts displayed the following lipid alterations: (1) Lower LC, but higher VLC-acylcarnitines accumulation, (2) higher levels of arachidonic acid (AA) and lower docosahexaenoic acid (DHA) contents in glycerophospholipids (GPLs), as well as (3) corresponding changes in pro-arrhythmogenic AA-derived isoprostanes and thromboxane B2 (higher), and anti-arrythmogenic DHA-derived neuroprostanes (lower). These changes were associated with remodeling in the expression of gene or protein markers of (1) GPLs remodeling: higher calcium-dependent phospholipase A2 and lysophosphatidylcholine-acyltransferase 2, (2) calcium handling perturbations, and (3) endoplasmic reticulum stress. Altogether, these results highlight global lipid dyshomeostasis beyond FAO in VLCAD-/- mouse hearts, which may set conditions predisposing the hearts to calcium mishandling and endoplasmic reticulum stress and thereby may contribute to the pathogenesis of arrhythmias in VLCADD in mice as well as in humans.

Impact of Dairy Intake on Plasma F2-IsoProstane Profiles in Overweight Subjects with Hyperinsulinemia: A Randomized Crossover Trial.

F2-IsoProstanes (F2-IsoPs) are major biomarkers of oxidative stress and are associated with type 2 diabetes (T2D). Further, plasma levels of F2-IsoPs may be modified by dairy products. The aim is to investigate the effect of high dairy product (HD) consumption compared to an adequate dairy product (AD) consumption on the level of F2-IsoPs among hyperinsulinemic subjects. In this crossover study, participants were randomized in two groups: HD (≥4 servings/day), or AD (≤2 servings/day) for six weeks. Fasting blood glucose and insulin were measured. The homeostatic model assessment of insulin resistance (HOMA-IR) was calculated. Six isomers of F2-IsoPs were quantified by HPLC-MS/MS. Twenty-seven subjects with hyperinsulinemia (mean age; 55 ± 13 years, BMI; 31.4 ± 3.3 kg/m2) were included. Fasting glucose, insulin and HOMA-IR were unchanged after HD or AD intervention. After HD intake, the total level of F2-IsoPs (p = 0.03), 5-F2t-IsoP (p = 0.002), and 8-F2t-IsoP (p = 0.004) decreased compared to AD. The 15-F2t-IsoP tended to be positively correlated with fasting blood glucose (r = 0.39, p = 0.08). Generally, F2-IsoPs levels were higher among men compared to women regardless of the dairy intake. Overall, intake of HD decreased plasma levels of F2-IsoPs compared to AD without modifying glycemic parameters.

The plasma antioxidant vitamin status of the INTAPP cohort examined: The unsuspected importance of ß-carotene and γ-tocopherol in preeclampsia.

OBJECTIVE: Examine the levels of plasma antioxidant vitamins before and during a treatment with placebo or vitamin E + C supplement to prevent preeclampsia (PE). STUDY DESIGN: Per-protocol analysis of a subset group of pregnant women (n = 295) from the International Trial of Antioxidants for the Prevention of PE (INTAPP) randomized case-control study. Normotensive receiving placebo or vitamins (n = 115 and 87 respectively) were compared to gestational hypertension (GH) without proteinuria (n = 30 and 27) and PE (n = 21 and 15). Vitamin quantification was performed at 12-18, 24-26 and 32-34 weeks of gestation. MAIN OUTCOME MEASURES: Coenzyme (Co) Q10, ß-carotene and vitamins E (α and γ forms) plasma levels. RESULTS: Vitamin E + C supplementation was found to increase the α-tocopherol levels by 40% but was associated with a 57% decrease in the γ-tocopherol isoform for all study groups (p < 0.001). The ß -carotene was lower in the PE than in the normotensive and GH groups (p < 0.001) while the level of CoQ10 remained unaffected. CONCLUSIONS: A more personalized approach that target the suboptimal levels of specific antioxidants without disturbing the α/γ-tocopherol ratio could be a more successful approach to counteract oxidative stress in PE.

Resolvin-D2 targets myogenic cells and improves muscle regeneration in Duchenne muscular dystrophy.

Lack of dystrophin causes muscle degeneration, which is exacerbated by chronic inflammation and reduced regenerative capacity of muscle stem cells in Duchenne Muscular Dystrophy (DMD). To date, glucocorticoids remain the gold standard for the treatment of DMD. These drugs are able to slow down the progression of the disease and increase lifespan by dampening the chronic and excessive inflammatory process; however, they also have numerous harmful side effects that hamper their therapeutic potential. Here, we investigated Resolvin-D2 as a new therapeutic alternative having the potential to target multiple key features contributing to the disease progression. Our in vitro findings showed that Resolvin-D2 promotes the switch of macrophages toward their anti-inflammatory phenotype and increases their secretion of pro-myogenic factors. Moreover, Resolvin-D2 directly targets myogenic cells and promotes their differentiation and the expansion of the pool of myogenic progenitor cells leading to increased myogenesis. These effects are ablated when the receptor Gpr18 is knocked-out, knocked-down, or blocked by the pharmacological antagonist O-1918. Using different mouse models of DMD, we showed that Resolvin-D2 targets both inflammation and myogenesis leading to enhanced muscle function compared to glucocorticoids. Overall, this preclinical study has identified a new therapeutic approach that is more potent than the gold-standard treatment for DMD.

Physical fitness is associated with prostaglandin F2α isomers during pregnancy.

INTRODUCTION: Pregnancy and physical activity are associated with oxidative stress and immune changes. We hypothesized that pregnant women physically more active in early pregnancy will display a better oxidative stress management and inflammatory response later in pregnancy compared with less active pregnant women. MATERIAL AND METHODS: Maternal physical activity using accelerometry monitors for 1 week and cardiorespiratory fitness (VO2 at anaerobic threshold) were assessed at 14-18 weeks in 58 pregnant women. Plasma and erythrocytes membrane samples were obtained from maternal blood samples at 14-18 and 34-37 weeks of pregnancy. Pro-inflammatory prostaglandin (PG) F2α and oxidative stress-derived F2-isoprostanes were measured by high-performance liquid chromatography coupled to tandem mass spectrometry. RESULTS: Higher physical activity levels at 14-18 weeks measured by mean counts per minute, >30 min/d of moderate to vigorous activity or >6500 steps/d at 14-18 weeks of pregnancy were associated with lower levels of total plasmatic PGF2α later in pregnancy. Concentrations of 5 F2-isomers in erythrocyte membranes in late pregnancy were significantly higher in the third (17.5-19.5 mL kg-1 min-1) and/or fourth (19.6-27.7 mL kg-1 min-1) quartiles of cardio-respiratory fitness compared to the first quartile (13.9-15.9 mL kg-1 min-1). CONCLUSIONS: Overall, higher cardio-respiratory fitness in early pregnancy is associated with enhanced erythrocyte membranes oxidation at 34-37 weeks reflecting a higher oxygen transfer capacity. Also, the most active women experienced lower circulating levels of pro-inflammatory PGF2α in plasma at 34-37 weeks, a marker associated with adverse antenatal inflammation-associated conditions. These results support the practice of physical activity by pregnant women.

Increased Dairy Product Intake Alters Serum Metabolite Profiles in Subjects at Risk of Developing Type 2 Diabetes.

SCOPE: Metabolomics is increasingly used to identify biomarkers of diet or chronic diseases, such as type 2 diabetes. Yet, metabolite signatures following dairy intake in hyperinsulinemic subjects have not been identified. The objective is to evaluate the effects of a high dairy diet (HD) for 6 weeks (4 servings or more per day), compared with an adequate dairy diet (AD) (2 servings or less per day), on serum metabolite profiles in hyperinsulinemic adults. METHODS AND RESULTS: In this crossover trial, subjects are randomized to HD or AD for 6 weeks. Serum metabolites are assessed using GC/MS. Twenty-six subjects completed the study. Levels of pentadecanoic acid, tyrosine and lathosterol are increased in HD, while 1,5-anhydrosorbitol, myo-inositol, 3-aminoisobutyric acid and beta-sitosterol are decreased (p < 0.05). Sorbitol levels are increased after AD, while hexanoic acid, lauric acid, l-kynurenine, methionine, and benzoic acid levels are reduced (p < 0.05). Histidine, caprylic acid, nonanoic acid, decanoic acid, lauric acid, heptadecanoic acid, and benzoic acid levels are increased in HD compared to AD, while malic acid levels are increased in AD compared with HD (p < 0.05). CONCLUSION: Higher dairy products intake modifies metabolite profiles in hyperinsulinemic subjects.

F2-isoprostanes and fatty acids profile in early pregnancy complicated by pre-existing diabetes.

BACKGROUND: Diabetes and pregnancy are both associated with oxidative stress, characterized by an increase of F2-isoprostanes from the non-enzymatic oxidation of arachidonic acid, a n - 6 polyunsaturated fatty acid (PUFA). We hypothesized that pregnant women with pre-existing diabetes will be characterized by elevated levels of specific F2-isoPs isomers and altered PUFA composition in plasma early pregnancy when compared to normoglycemic controls. METHODS: Plasma samples from 23 women with uncomplicated pregnancies and 11 women with pre-existing diabetes in pregnancy were collected between 12 and 18 weeks of pregnancy (MIROS cohort). Six F2-isoprostanes isomers were measured by high-performance liquid chromatography coupled to tandem mass spectrometry. Fatty acids concentrations in plasmatic phospholipids were measured by gas chromatography coupled to a flame ionization detector. RESULTS: F2-isoprostanes, specifically the 8-iso-15(R)-PGF2α levels, were 67% higher in diabetic than normoglycemic pregnancies (p = 0.026). The total n - 6 PUFA and arachidonic acid level did not differ between study groups. In contrast, total n - 3 level was 32% lower in diabetic pregnancies than in controls (p = 0.002); EPA(20:5) and DHA(22:6) being specifically reduced (p = 0.035 and p = 0.003 respectively). Delta-6-desaturase (D6D) activity index, calculated using fatty acid ratios, was 9% lower in pre-existing diabetes than in controls (p = 0.042). CONCLUSIONS: Pre-existing diabetes in early pregnancy displays a distinctive F2-isoprostanes profile when compared to other pathologies of pregnancy, such as preeclampsia, as previously assessed in the same cohort.

Modulation of the biomarkers of inflammation and oxidative stress by ruminant trans fatty acids and dairy proteins in vascular endothelial cells (HUVEC).

This study aimed to determine whether dairy macronutrients alter markers of inflammation and oxidative stress in endothelial cells. Human endothelial cells (HUVEC) were treated with ruminant trans fatty acids (rTFA), either trans-vaccenic acid (tVA) or trans-palmitoleic acid (tPA), whey protein hydrolysate, leucine or combinations of rTFA and dairy protein compounds. Industrial TFA elaidic acid (EA) was also investigated and compared with rTFA. Inflammatory prostaglandins (PG) and F2-isoprostanes (F2-isoP) isomers, markers of oxidative stress, were assessed in cell supernatants by LC-MS/MS. Both tVA and tPA, as well as whey protein hydrolysate, decreased TNFα-induced PG excretion. Combinations of rTFA and dairy protein compounds decreased inflammation to a similar extent than rTFA alone. EA increased class VI F2-isoP isomers, whereas tVA mostly raised class III isomers. In summary, rTFA decreased inflammatory markers and increased oxidative stress markers in endothelial cells. Combinations of rTFA with whey proteins or leucine showed no additive effect.

Fatty acid composition of birds and game hunted by the Eastern James Bay Cree people of Québec.

BACKGROUND: Indigenous peoples have traditionally relied on foods hunted and gathered from their immediate environment. The Eastern James Bay Cree people consume wild game and birds, and these are believed to provide health as well as cultural benefits. OBJECTIVE: To determine the fatty acid (FA) composition of traditional game and bird meats hunted in the Eastern James Bay area. DESIGN: Harvested traditional game and birds were analysed for FA composition. A total of 52 samples from six wildlife species were collected in the areas of Chisasibi, Waswanipi and Mistissini, of which 35 were from birds (white partridge and Canada goose) and 17 were from land animals (beaver, moose, caribou and black bear). RESULTS: Alpha-linolenic acid (ALA) was the most common n-3 polyunsaturated fatty acid (PUFA) in all samples except for the black bear flesh, in which it was docosapentaenoic acid (DPAn-3). In white partridge, beaver and caribou flesh, PUFAs (mainly n-6) were the most common category of fats while in goose, moose and black bear flesh, monounsaturated fatty acids (MUFAs) predominated. In all species, saturated fatty acids (SFAs) were the second most important FAs. It would appear that in the land animals and birds that were analysed, the SFA content was lower and the PUFA content was higher than store-bought meats giving them a more heart-healthy profile. CONCLUSIONS: These results showed that the FA composition of game species consumed by the James Bay Cree population is consistent with a beneficial diet and that traditional foods should continue to be promoted among the Cree people to provide better physical health as well as social and spiritual benefits.

Plasma F2-isoprostane class VI isomers at 12-18 weeks of pregnancy are associated with later occurrence of preeclampsia.

Preeclampsia (PE) has long been associated with early oxidative stress, although the symptoms occur later in pregnancy. We have hypothesized that the oxidative stress in PE, as characterized by the presence of F2-isoprostane (F2-isoP) isomers in late pregnancy, should already be present in plasma at the first regular visit of the obstetrical follow-up. There are 64 possible isomers of F2-isoPs derived from the oxidation of arachidonic acid (AA), but only one of these isomers has been investigated so far in PE, the classical 8-iso-PGF2α. Here, we have investigated two regioisomers of class III (8-iso-15(R)-PGF2α and 8-iso-PGF2α) and a mix of two isomers of class VI ((±)5-iPF2α-VI) in plasma samples collected prospectively at 12-18 weeks from normotensive controls (n = 60) and pregnant mothers who developed PE later in pregnancy (n = 33). The plasma samples were subjected to alkaline hydrolysis followed by liquid-liquid extraction to extract total F2-isoPs for later quantification by HPLC-MS/MS. The F2-isoPs were normalized to either plasma volume or polyunsaturated fatty acid (PUFA) levels measured by GC-FID in plasma phospholipids. Early in pregnancy, only the class VI F2-isoP isomers were found at concentrations significantly higher in women developing PE later in pregnancy (+13%; p = 0.0074). Normalization of F2-isoPs to their substrate, AA, or the omega-3 to omega-6 ratio improved the predictability of PE as determined by receiver operating characteristic (from area under the curve of 0.67 to 0.68 and 0.70 respectively). Interestingly, omega-3 fatty acids were 25% higher in the control group than in the PE group (P = 0.0225). Omega-6 PUFAs correlated with F2-Isop isomers only in cases of PE (r > 0.377; P >0.03, Spearman correlation). In sum, this study indicates that specific isomers of class VI are significant predictors of PE. This work also suggests that F2-isoP isomers are not all generated and eliminated to the same extent and are influenced by the PUFA composition of plasma phospholipids.

F2-isoprostanes are correlated with trans fatty acids in the plasma of pregnant women.

We hypothesized that the mild physiological oxidative stress present during pregnancy could increase both, plasma F2-isoprostanes (F2-isoPs) by lipid oxidation and trans fatty acids (TFA) through cis-trans isomerization respectively. Plasma samples collected at 12-18 weeks (MIROS cohort; n=65) and 38-41 weeks of pregnancy (CHUL cohort; n=21) were subjected to alkaline hydrolysis followed by liquid-liquid extraction in order to extract total F2-isoPs for quantification by HPLC-MS/MS. Several positive correlations were found between F2-isoPs and TFA, measured by GC-FID in plasma phospholipids, such as 6t-18:1, 9t-18:1 and 9t,12c-18:2 (r>0.306; p<0.045). Despite its low level, the 9t,12c-18:2 trans isomer, known to be associated to cardiovascular diseases, showed the most significant correlations with F2-isoPs. No correlation was observed between F2-isoPs and 9t-16:1 or 11t-18:1. In summary, this study suggests either a concomitant phenomenon or a competition between lipid peroxidation and cis-trans isomerisation of the cis precursor fatty acid in vivo during pregnancy.