Polyunsaturated fatty acids and inflammatory processes: New twists in an old tale. Biochimie. 2009;91:791-795. [PMID: 19455748 DOI: 10.1016/j.biochi.2009.01.008]

High fat diet increases the severity of collagen-induced arthritis in mice by altering the gut microbial community

OBJECTIVES

Research has demonstrated that obesity may be associated with rheumatoid arthritis (RA). In addition, gut microbiota and its metabolites contribute to the occurrence and development of RA and obesity. However, the mechanism by which obesity affects RA remains unclear. In this study, we aimed to investigate whether gut microbiota and their metabolites alter the effects of high fat diet (HFD) on the severity of collagen-induced arthritis (CIA) in mice.

METHODS

Briefly, mice were divided into normal group (N), CIA model group (C), HFD group (T), and HFD CIA group (CT). Hematoxylin and Eosin staining(HE) and Safranin O-fast green staining were conducted, and levels of blood lipid and inflammatory cytokines were measured. 16S rDNA sequencing technique and liquid chromatography-mass spectrometry (LC-MS)-based metabolomics were performed to explore changes in the microbiota structure to further reveal the pathomechanism of HFD on CIA.

RESULTS

HFD aggravated the severity of CIA in mice. The CT group had the highest proportion of microbial abundance of Blautia, Oscillibacter, Ruminiclostridium-9, and Lachnospiraceae UCG 006 at the genus level, but had a lower proportion of Alistipes. Additionally, the fecal metabolic phenotype of the combined CT group shows significant changes, with differential metabolites enriched in 9 metabolic pathways, including primary bile acid biosynthesis, arginine biosynthesis, sphingolipid metabolism, purine metabolism, linoleic acid metabolism, oxytocin signaling pathway, aminoacyl-tRNA biosynthesis, the pentose phosphate pathway, and sphingolipid signaling pathway. Correlation analysis revealed that some of the altered gut microbiota genera were strongly correlated with changes in fecal metabolites, total cholesterol (TC), triglyceride (TG), and inflammatory cytokine levels.

CONCLUSIONS

This study shows that HFD may aggravate inflammatory reaction in CIA mice by altering the gut microbiota and metabolic pathways.

Adverse effects of excessive dietary arachidonic acid on survival, PUFA-derived enzymatic and non-enzymatic oxylipins, stress response in rainbow trout fry

Arachidonic acid (C20: 4n-6, AA) plays a fundamental role in fish physiology, influencing growth, survival and stress resistance. However, imbalances in dietary AA can have detrimental effects on fish health and performance. Optimal AA requirements for rainbow trout have not been established. This study aimed to elucidate the effects of varying dietary AA levels on survival, growth, long-chain polyunsaturated fatty acid (LC-PUFA) biosynthetic capacity, oxylipin profiles, lipid peroxidation, and stress resistance of rainbow trout fry. Over a period of eight weeks, 4000 female rainbow trout fry at the resorptive stage (0.12 g) from their first feeding were fed diets with varying levels of AA (0.6%, 1.1% or 2.5% of total fatty acids) while survival and growth metrics were closely monitored. The dietary trial was followed by an acute confinement stress test. Notably, while the fatty acid profiles of the fish reflected dietary intake, those fed an AA-0.6% diet showed increased expression of elongase5, highlighting their inherent ability to produce LC-PUFAs from C18 PUFAs and suggesting potential AA or docosapentaenoic acidn-6 (DPAn-6) biosynthesis. However, even with this biosynthetic capacity, the trout fed reduced dietary AA had higher mortality rates. The diet had no effect on final weight (3.38 g on average for the three diets). Conversely, increased dietary AA enhanced eicosanoid production from AA, suggesting potential inflammatory and oxidative consequences. This was further evidenced by an increase in non-enzymatic lipid oxidation metabolites, particularly in the AA-2.5% diet group, which had higher levels of phytoprostanes and isoprostanes, markers of cellular oxidative damage. Importantly, the AA-1.1% diet proved to be particularly beneficial for stress resilience. This was evidenced by higher post-stress turnover rates of serotonin and dopamine, neurotransmitters central to the fish's stress response. In conclusion, a dietary AA intake of 1.1% of total fatty acids appears to promote overall resilience in rainbow trout fry.

Restoring retinal polyunsaturated fatty acid balance and retina function by targeting ceramide in AdipoR1-deficient mice

Mutations in the adiponectin receptor 1 gene (AdipoR1) lead to retinitis pigmentosa and are associated with age-related macular degeneration. This study explores the effects of AdipoR1 gene deficiency in mice, revealing a striking decline in ω3 polyunsaturated fatty acids (PUFA), an increase in ω6 fatty acids, and elevated ceramides in the retina. The AdipoR1 deficiency impairs peroxisome proliferator-activated receptor α signaling, which is crucial for FA metabolism, particularly affecting proteins associated with FA transport and oxidation in the retina and retinal pigmented epithelium. Our lipidomic and proteomic analyses indicate changes that could affect membrane composition and viscosity through altered ω3 PUFA transport and synthesis, suggesting a potential influence of AdipoR1 on these properties. Furthermore, we noted a reduction in the Bardet-Biedl syndrome proteins, which are crucial for forming and maintaining photoreceptor outer segments that are PUFA-enriched ciliary structures. Diminution in Bardet-Biedl syndrome-proteins content combined with our electron microscopic observations raises the possibility that AdipoR1 deficiency might impair ciliary function. Treatment with inhibitors of ceramide synthesis led to substantial elevation of ω3 LC-PUFAs, alleviating photoreceptor degeneration and improving retinal function. These results serve as the proof of concept for a ceramide-targeted strategy to treat retinopathies linked to PUFA deficiency, including age-related macular degeneration.

Predictors of upstream inflammation and oxidative stress pathways during early pregnancy

BACKGROUND

Inflammation and oxidative stress are critical to pregnancy, but most human study has focused on downstream, non-causal indicators. Oxylipins are lipid mediators of inflammation and oxidative stress that act through many biological pathways. Our aim was to characterize predictors of circulating oxylipin concentrations based on maternal characteristics.

METHODS

Our study was conducted among 901 singleton pregnancies in the LIFECODES Fetal Growth Study, a nested case-cohort with recruitment from 2007 to 2018. We measured a targeted panel of oxylipins in early pregnancy plasma and urine samples from several biosynthetic pathways, defined by the polyunsaturated fatty acid (PUFA) precursor and enzyme group. We evaluated levels across predictors, including characteristics of participants' pregnancy, socioeconomic determinants, and obstetric and medical history.

RESULTS

Current pregnancy and sociodemographic characteristics were the most important predictors of circulating oxylipins concentrations. Plasma oxylipins were lower and urinary oxylipins higher for participants with a later gestational age at sampling (13-23 weeks), higher prepregnancy BMI (obesity class I, II, or III), Black or Hispanic race and ethnicity, and lower socioeconomic status (younger age, lower education, and uninsured). For example, compared to those with normal or underweight prepregnancy BMI, participants with class III prepregnancy obesity had 45-46% lower plasma epoxy-eicosatrienoic acids, the anti-inflammatory oxylipins produced from arachidonic acid (AA) by cytochrome P450, and had 81% higher urinary 15-series F2-isoprostanes, an indicator of oxidative stress produced from non-enzymatic AA oxidation. Similarly, in urine, Black participants had 92% higher prostaglandin E2 metabolite, a pro-inflammatory oxylipin, and 41% higher 5-series F2-isoprostane, an oxidative stress indicator.

CONCLUSIONS

In this large pregnancy study, we found that circulating levels of oxylipins were different for participants of lower socioeconomic status or of a systematically marginalized racial and ethnic groups. Given associations differed along biosynthetic pathways, results provide insight into etiologic links between maternal predictors and inflammation and oxidative stress.

Nutrition as the foundation for successful aging: a focus on dietary protein and omega-3 polyunsaturated fatty acids

Skeletal muscle plays a critical role throughout the aging process. People living with sarcopenia, a progressive and generalized loss of skeletal muscle mass and function, often experience diminished quality of life, which can be attributed to a long period of decline and disability. Therefore, it is important to identify modifiable factors that preserve skeletal muscle and promote successful aging (SA). In this review, SA was defined as (1) low cardiometabolic risk, (2) preservation of physical function, and (3) positive state of wellbeing, with nutrition as an integral component. Several studies identify nutrition, specifically high-quality protein (eg, containing all essential amino acids), and long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), as positive regulators of SA. Recently, an additive anabolic effect of protein and n-3 PUFAs has been identified in skeletal muscle of older adults. Evidence further suggests that the additive effect of protein and n-3 PUFAs may project beyond skeletal muscle anabolism and promote SA. The key mechanism(s) behind the enhanced effects of intake of protein and n-3 PUFAs needs to be defined. The first objective of this review is to evaluate skeletal muscle as a driver of cardiometabolic health, physical function, and wellbeing to promote SA. The second objective is to examine observational and interventional evidence of protein and n-3 PUFAs on skeletal muscle to promote SA. The final objective is to propose mechanisms by which combined optimal intake of high-quality protein and n-3 PUFAs likely play a key role in SA. Current evidence suggests that increased intake of protein above the Recommended Dietary Allowance and n-3 PUFAs above the Dietary Guidelines for Americans recommendations for late middle-aged and older adults is required to maintain skeletal muscle mass and to promote SA, potentially through the mechanistical target of rapamycin complex 1 (mTORC1).

Omega-3 fatty acids and endothelial function: A GRADE-assessed systematic review and meta-analysis

INTRODUCTION

N-3 polyunsaturated fatty acids (PUFAs) supplementation has been reported to have an impact on flow-mediated dilatation (FMD), a conventionally used clinical technique for estimating endothelial dysfunction. However, its proven effects on endothelial function are unclear. This systematic review and meta-analysis were conducted to evaluate the effects of n-3 PUFAs supplementation on FMD of the brachial artery.

METHOD

This study was performed following the PRISMA guidelines. To identify eligible RCTs, a systematic search was completed in PubMed/Medline, Scopus and Web of Science using relevant keywords. A fixed- or random-effects model was utilized to estimate the weighted mean difference (WMD) and 95% confidence interval (95% CI).

RESULTS

Thirty-two studies (with 35 arms) were included in this meta-analysis, involving 2385 subjects with intervention duration ranging from 4 to 48 weeks. The pooled meta-analysis demonstrated a significant effect of omega-3 on FMD (WMD = 0.8%, 95% CI = 0.3-1.3, p = .001) and heterogeneity was significant (I2  = 82.5%, p < .001).

CONCLUSION

We found that n-3 PUFA supplementation improves endothelial function as estimated by flow-mediated dilatation of the brachial artery.

Pumpkin seed oil: a comprehensive review of extraction methods, nutritional constituents, and health benefits

Pumpkin seed oil (PSO), a rich source of nutrients, is extracted from the seeds of different pumpkin varieties for food and medicines. This article aims to provide an evidence-based review of the literature and to explore the extraction technologies, nutritional properties, and biological activity of PSO. From previous literature, PSO contains a large proportion of unsaturated fatty acids, with linoleic acid as the main component, and an amount of tocopherol, phytosterol, and phenolic acids. Some differences in the yield, composition, and physicochemical properties of PSO can be associated with the pumpkin's cultivars and the extraction methods. Some novel technologies involved in supercritical fluid extraction, enzyme-assisted aqueous extraction, and ultrasound-assisted extraction have been replacing the conventional technologies gradually as promising methods for the safe, non-polluting, and effective recovery of PSO. This healthy vegetable oil was reported by several in vitro and in vivo studies to have potential protective roles in oxidative stress, inflammation, cancer, and cardiovascular diseases. © 2023 Society of Chemical Industry.

Omega-3 supplementation and outcomes of heart failure: A systematic review of clinical trials

BACKGROUNDS

Omega-3 supplements are endorsed for heart failure (HF) patients to reduce hospitalizations and mortality, offering anti-inflammatory and cardioprotective benefits.

METHODS

A comprehensive search was conducted in various databases until November 2022. Eligible studies included clinical trials on patients with HF. Data extraction covered study details, omega-3 specifics, outcomes, and limitations. The JADAD scale was used to assess the risk of bias in randomized controlled trials.

RESULTS

The review process involved 572 records from database searches, resulting in 19 studies after eliminating duplicates and screening. These studies assessed the impact of omega-3 on various clinical outcomes, such as mortality, hospitalization, cardiac function, and quality of life. Studied duration varied from weeks to years. Omega-3 supplementation demonstrated potential benefits such as improved heart function, reduced inflammation, and decreased risk of cardiovascular events.

CONCLUSION

Omega-3 supplementation could benefit heart disease treatment, potentially reducing therapy duration and improving outcomes. Starting omega-3 supplementation for HF patients seems favorable.

Effects of increasing omega-3 fatty acids on growth performance, immune response, and mortality in nursery pigs

Three experiments evaluated omega-3 fatty acids, provided by O3 trial feed, on nursery pig growth performance, mortality, and response to an LPS immune challenge or natural Porcine reproductive and respiratory virus (PRRSV) outbreak. In experiment 1, 350 pigs (241 × 600, DNA; initially 5.8 kg) were used. Pens of pigs were randomly assigned to one of the five dietary treatments containing increasing omega-3 fatty acids (0%, 1%, 2%, 3%, and 4% O3 trial feed) with 14 replications per treatment. On day 25, two pigs per pen were injected intramuscularly with 20 μg Escherichia coli LPS per kg BW and one pig per pen was injected with saline as a control. Body temperature was taken from all three pigs prior to and 2, 4, 6, and 12 h post-LPS challenge. Serum IL-1β and TNF-α concentrations were determined in LPS-challenged pigs 24 h prior and 4 h post-LPS challenge. There was no interaction between treatment and time for change in body temperature (P > 0.10). Overall, increasing the O3 trial feed did not affect (P > 0.10) ADG, ADFI, G:F, IL-1β, or TNF-α. In experiment 2, 1,056 pigs (PIC TR4 × [Fast LW × PIC L02] initially 7.3 kg) were used. Pens of pigs were randomly assigned to one of the four dietary treatments containing increasing omega-3 fatty acids (0%, 0.75%, 1.5%, and 3% O3 trial feed) with 12 replications per treatment. Oral fluids tested negative on days 7 and 14, but then positive for North American PRRSV virus via PCR on days 21, 28, 35, and 42. Overall, increasing O3 trial feed increased (linear, P < 0.001) ADG, ADFI, and G:F and decreased (linear, P = 0.027) total removals and mortality. In experiment 3, 91,140 pigs (DNA 600 × PIC 1050; initially 5.1 kg), originating from PRRSV-positive sow farms, were used across eight nursery sites. Each site contained five barns with two rooms per barn and ~1,100 pigs per room. Rooms of pigs were blocked by nursery site and allocated within sow source to one of the two dietary treatments (control or 3% O3 trial feed) with 40 replications per treatment. Oral fluids from 61 of the 80 rooms tested positive for North American PRRSV virus 1 wk postweaning and 78 of the 80 rooms tested positive 3 wk after weaning. Overall, O3 trial feed did not affect ADG, ADFI, or G:F but increased (P < 0.001) total removals and mortalities. In summary, increasing omega-3 fatty acids, sourced by O3 trial feed, did not improve growth performance or immune response in healthy pigs given an LPS challenge. However, it appears that if omega-3 fatty acids are fed prior to a natural PRRSV break (as in experiment 2), growth performance may be improved, and mortality reduced.

Fish consumption and its lipid modifying effects - A review of intervention studies

Fish is an important source of nutrients, particularly the long chain n-3 polyunsaturated fatty acids (n-3 PUFAs). The incorporation of fish into the diet has been shown to have several health benefits, including lowering the risk of cardiovascular disease (CVD). Elevated plasma lipids are one of the main modifiable risk factors contributing to CVD and may be partly mediated by n-3 PUFAs. Although n-3 PUFAs in the form of supplementation have been shown to exert lipid modifying effects, the effects of fish consumption on the lipid profile have not been well summarised to date. Therefore, the aim of the present review is to discuss the current evidence from intervention studies investigating the effect of fish consumption on the lipid profile in both apparently healthy and non-healthy populations. Existing evidence appears to support the role of fish in promoting a shift towards a less inflammatory lipid profile through raising n-3 PUFAs and potentially lowering n-6 PUFA and triglyceride concentrations in both healthy and non-healthy populations. Fish consumption has a negligible effect on cholesterol concentrations; however, fish consumption may promote a small increase in high density lipoprotein (HDL) cholesterol amongst people with lower HDL at baseline. Limited studies have shown fish consumption to result in shifts in phospholipid and sphingolipid species and structure, albeit it is not yet clear whether these alterations have any meaningful impact on CVD risk. Future well-designed studies that utilise NMR and/or lipidomics analysis are warranted to explore the effects of these shifts in lipid content and structure in the context of disease development. Public health guidance should emphasise the cardioprotective benefits of fish and encourage consumption particularly in the Global North where fish consumption remains low.

New Insights into Prospective Health Potential of ω-3 PUFAs

PURPOSE OF REVIEW

Docosahexaenoic acid and eicosapentaenoic acid are the two essential long-chain ω-3 polyunsaturated fatty acids (ω-3 PUFAs) promoting human health which are obtained from diet or supplementation. The eicosanoids derived from ω-6 and ω-3 PUFAs have opposite characteristics of pro- and anti-inflammatory activities. The proinflammatory effects of ω-6 PUFAs are behind the pathology of the adverse health conditions of PUFA metabolism like cardiovascular diseases, neurological disorders, and inflammatory diseases. A balanced ω-6 to ω-3 ratio of 1-4:1 is critical to prevent the associated disorders. But due to modern agricultural practices, there is a disastrous shift in this ratio to 10-20:1. This review primarily aims to discuss the myriad health potentials of ω-3 PUFAs uncovered through recent research. It further manifests the importance of maintaining a balanced ω-6 to ω-3 PUFA ratio.

RECENT FINDINGS

ω-3 PUFAs exhibit protective effects against diabetes mellitus-associated complications including diabetic retinopathy, diabetic nephropathy, and proteinuria. COVID-19 is also not an exception to the health benefits of ω-3 PUFAs. Supplementation of ω-3 PUFAs improved the respiratory and clinical symptoms in COVID-19 patients. ω-3 PUFAs exhibit a variety of health benefits including anti-inflammatory property and antimicrobial property and are effective in protecting against various health conditions like atherosclerosis, cardiovascular diseases, diabetes mellitus, COVID-19, and neurological disorders. In the present review, various health potentials of ω-3 PUFAs are extensively reviewed and summarized. Further, the importance of a balanced ω-6 to ω-3 PUFA ratio has been emphasized besides stating the diverse sources of ω-3 PUFA.

n-6 fatty acid biomarkers and incident atrial fibrillation: an individual participant-level pooled analysis of 11 international prospective studies

BACKGROUND

The presence of atrial fibrillation (AF) is associated with an over 2-fold increased risk of stroke, heart failure, and cardiovascular mortality. Long chain n-6 PUFAs have been suggested to have a variety of beneficial biologic effects that may reduce AF development; however, prior studies evaluating this relationship are limited.

OBJECTIVES

We prospectively evaluated the association between circulating levels of linoleic acid (LA) and arachidonic acid (AA) with incident AF.

METHODS

We used participant-level data from a global consortium of 11 prospective cohort studies with measurements of LA and AA in adults (aged ≥18 y). Participating studies conducted de novo analyses using a prespecified analytical plan with harmonized definitions for exposures, outcomes, covariates, and subgroups. Associations were pooled using inverse-variance weighted meta-analysis.

RESULTS

Among 41,335 participants, 6173 incident cases of AF were ascertained, with median follow-up time of 14 y. In multivariable analysis, per interquintile range (difference between the 10th and 90th percentiles for each fatty acid), circulating n-6 levels were not associated with incident AF. For LA, the hazard ratio per interquintile range was 0.96 (95% confidence interval [CI]: 0.89, 1.04), and for AA, 1.02 (95% CI: 0.94, 1.10), with little evidence of heterogeneity between cohorts. Associations were similarly nonsignificant across subgroups of age, race, and biomarker fraction.

CONCLUSIONS

Biomarkers of n-6 fatty acids including LA and AA are not associated with incident AF. These findings suggest that overall effects of n-6 PUFAs on influencing AF development are neutral.

COVID-19 associated thyroid dysfunction and other comorbidities and its management using phytochemical-based therapeutics: a natural way

The present severe acute respiratory syndrome-2 (SARS-CoV-2) mediated Coronavirus pandemic (COVID-19) and post-COVID-19 complications affect human life drastically. Patients who have been cured of COVID-19 infection are now experiencing post-COVID-19 associated comorbidities, which have increased mortality rates. The SARS-CoV-2 infection distresses the lungs, kidneys, gastrointestinal tract, and various endocrine glands, including the thyroid. The emergence of variants which includes Omicron (B.1.1.529) and its lineages threaten the world severely. Among different therapeutic approaches, phytochemical-based therapeutics are not only cost-effective but also have lesser side effects. Recently a plethora of studies have shown the therapeutic efficacy of various phytochemicals for the treatment of COVID-19. Besides this, various phytochemicals have been found efficacious in treating several inflammatory diseases, including thyroid-related anomalies. The method of the phytochemical formulation is quick and facile and the raw materials for such herbal preparations are approved worldwide for human use against certain disease conditions. Owing to the advantages of phytochemicals, this review primarily discusses the COVID-19-related thyroid dysfunction and the role of key phytochemicals to deal with thyroid anomaly and post-COVID-19 complications. Further, this review shed light on the mechanism via which COVID-19 and its related complication affect organ function of the body, along with the mechanistic insight into the way by which phytochemicals could help to cure post-COVID-19 complications in thyroid patients. Considering the advantages offered by phytochemicals as a safer and cost-effective medication they can be potentially used to combat COVID-19-associated comorbidities.

Mitigation of Insulin Resistance by Natural Products from a New Class of Molecules, Membrane-Active Immunomodulators

Insulin resistance (IR), accompanied by an impaired cellular glucose uptake, characterizes diverse pathologies that include, but are not limited to, metabolic disease, prediabetes and type 2 diabetes. Chronic inflammation associated with deranged cellular signaling is thought to contribute to IR. The key molecular players in IR are plasma membrane proteins, including the insulin receptor and glucose transporter 4. Certain natural products, such as lipids, phenols, terpenes, antibiotics and alkaloids have beneficial effects on IR, yet their mode of action remains obscured. We hypothesized that these products belong to a novel class of bioactive molecules that we have named membrane-active immunomodulators (MAIMs). A representative MAIM, the naturally occurring medium chain fatty acid ester diethyl azelate (DEA), has been shown to increase the fluidity of cell plasma membranes with subsequent downstream effects on cellular signaling. DEA has also been shown to improve markers of IR, including blood glucose, insulin and lipid levels, in humans. The literature supports the notion that DEA and other natural MAIMs share similar mechanisms of action in improving IR. These findings shed a new light on the mechanism of IR mitigation using natural products, and may facilitate the discovery of other compounds with similar activities.

Astaxanthin improves fatty acid dysregulation in diabetes by controlling the AMPK-SIRT1 pathway

Due to the rising prevalence of metabolic disorders, including type 2 diabetes (T2DM), new prevention and treatment strategies are needed. The aim was to examine the effect of astaxanthin (AST) on the major regulatory metabolism pathway SIRT-MAPK and fatty acid (FA) profile of plasma in patients with T2DM. This clinical trial included 68 T2DM patients randomly assigned to receive 10 mg/day of oral AST (n = 34) or placebo (n = 33) for 12 weeks. The expression level of SIRT1, AMPK activity, and the level of fatty acids in the serum were examined. The results showed that AST could modify the serum levels of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA), particularly that of Arachidonic acid, from 11.31±0.35 to 8.52±0.72 %. Also, AST increased the expression and activity levels of SIRT1 and AMPK, respectively. Pearson analysis also revealed a significant association between AMPK activity and Linoleic acid serum (LA) levels (~ -0.604, p~0.013). AST can modify the FA profile of plasma by inducing metabolizing cells to uptake them. Also, it can activate the SIRT-AMPK pathway related to metabolism regulation. See also Figure 1(Fig. 1).

Targeted Desorption Electrospray Ionization Mass Spectrometry Imaging for Drug Distribution, Toxicity, and Tissue Classification Studies

With increased use of mass spectrometry imaging (MSI) in support of pharmaceutical research and development, there are opportunities to develop analytical pipelines that incorporate exploratory high-performance analysis with higher capacity and faster targeted MSI. Therefore, to enable faster MSI data acquisition we present analyte-targeted desorption electrospray ionization–mass spectrometry imaging (DESI-MSI) utilizing a triple-quadrupole (TQ) mass analyzer. The evaluated platform configuration provided superior sensitivity compared to a conventional time-of-flight (TOF) mass analyzer and thus holds the potential to generate data applicable to pharmaceutical research and development. The platform was successfully operated with sampling rates up to 10 scans/s, comparing positively to the 1 scan/s commonly used on comparable DESI-TOF setups. The higher scan rate enabled investigation of the desorption/ionization processes of endogenous lipid species such as phosphatidylcholines and a co-administered cassette of four orally dosed drugs—erlotininb, moxifloxacin, olanzapine, and terfenadine. This was used to enable understanding of the impact of the desorption/ionization processes in order to optimize the operational parameters, resulting in improved compound coverage for olanzapine and the main olanzapine metabolite, hydroxy-olanzapine, in brain tissue sections compared to DESI-TOF analysis or matrix-assisted laser desorption/ionization (MALDI) platforms. The approach allowed reducing the amount of recorded information, thus reducing the size of datasets from up to 150 GB per experiment down to several hundred MB. The improved performance was demonstrated in case studies investigating the suitability of this approach for mapping drug distribution, spatially resolved profiling of drug-induced nephrotoxicity, and molecular–histological tissue classification of ovarian tumors specimens.

Metabolomics in Corneal Diseases: A Narrative Review from Clinical Aspects

Corneal pathologies may have subtle manifestations in the initial stages, delaying diagnosis and timely treatment. This can lead to irreversible visual loss. Metabolomics is a rapidly developing field that allows the study of metabolites in a system, providing a complementary tool in the early diagnosis and management of corneal diseases. Early identification of biomarkers is key to prevent disease progression. The advancement of nuclear magnetic resonance and mass spectrometry allows the identification of new biomarkers in the analysis of tear, cornea, and aqueous humor. Novel perspectives on disease mechanisms are identified, which provide vital information for potential targeted therapies in the future. Current treatments are analyzed at a molecular level to offer further information regarding their efficacy. In this article, we provide a comprehensive review of the metabolomic studies undertaken in the cornea and various pathologies such as dry eye disease, Sjogren’s syndrome, keratoconus, post-refractive surgery, contact lens wearers, and diabetic corneas. Lastly, we discuss the exciting future that metabolomics plays in cornea research.

Chlamydomonas reinhardtii: A Factory of Nutraceutical and Food Supplements for Human Health

Chlamydomonas reinhardtii (C. reinhardtii) is one of the most well-studied microalgae organisms that revealed important information for the photosynthetic and metabolic processes of plants and eukaryotes. Numerous extensive studies have also underpinned its great potential as a biochemical factory, capable of producing various highly desired molecules with a direct impact on human health and longevity. Polysaccharides, lipids, functional proteins, pigments, hormones, vaccines, and antibodies are among the valuable biomolecules that are produced spontaneously or under well-defined conditions by C. reinhardtii and can be directly linked to human nutrition and diet. The aim of this review is to highlight the recent advances in the field focusing on the most relevant applications related to the production of important biomolecules for human health that are also linked with human nutrition and diet. The limitations and challenges are critically discussed along with the potential future applications of C. reinhardtii biomass and processed products in the field of nutraceuticals and food supplements. The increasing need for high-value and low-cost biomolecules produced in an environmentally and economy sustainable manner also underline the important role of C. reinhardtii.

Effects of polyunsaturated fatty acid supplementation on plasma and follicular fluid resolvin D1 concentration and mRNA abundance in granulosa cells in ewes

The aim of this experiment was to evaluate the effect of increasing dietary omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation on plasma and follicular fluid resolvin D1 (RvD1) concentration and the mRNA expression of genes related to RvD1 production, inflammatory response, oxidative stress, hormone receptors and production, and free fatty acid receptors in the granulosa cells of ewes. Dorset × Hampshire ewes (n = 24) aged 2 to 4 yr and with an initial body weight (BW) of 84.08 ± 13.18 kg were blocked by body condition score (BCS) and BW, and randomly assigned to 12 pens. Each pen within each block was randomly assigned to one of three treatments: 1) diet without fatty acid supplementation (control), 2) diet with 0.5% n-3 PUFA supplementation (PUFA0.5), and 3) diet with 1% n-3 PUFA supplementation (PUFA1). BW, BCS, and blood samples were obtained on day 1 and every 21 d for 3 mo. Ewes were then synchronized, superstimulated, and ovariectomized. Antral follicles were aspirated to evaluate RvD1 concentration in follicular fluid, and granulosa cells were used to determine mRNA abundance. Data were analyzed as a randomized complete block design using a mixed model (MIXED or GLIMMIX with log as a link function when data presented a nonnormal distribution). A polynomial effect of treatments was used to analyze RvD1 concentration and mRNA expression when there was no interaction. In addition, the correlation between plasma and follicular fluid RvD1 concentration was evaluated. We found no differences in BW (P = 0.28) and BCS (P = 0.29) between treatments. The concentration of RvD1 in plasma and follicular fluid linearly increased (P = 0.03) and tended to increase (P = 0.06) concomitantly to increasing PUFA supplementation. Plasma and follicular fluid RvD1 concentrations were positively correlated (r = 0.61; P < 0.01). The abundance of GPX1 and GPR32 mRNA tended to increase linearly with increasing PUFA supplementation (P = 0.06). In addition, PUFA supplementation linearly decreased and tended to decrease IL-1β and COX-2 mRNA abundance (P = 0.01 and P = 0.06, respectively). In conclusion, the correlation between plasma and follicular fluid RvD1 concentration indicates a relationship between both compartments. Also, the decrease of IL-1β and the increase of GPX1 mRNA abundance after PUFA supplementation could have beneficial effects on follicle development.

Differences in the serum metabolic profile to identify potential biomarkers for cyanotic versus acyanotic heart disease

BACKGROUND

Growth retardation, malnutrition, and failure to thrive are some of the consequences associated with congenital heart diseases. Several metabolic factors such as hypoxia, anoxia, and several genetic factors are believed to alter the energetics of the heart. Timely diagnosis and patient management is one of the major challenges faced by the clinicians in understanding the disease and provide better treatment options. Metabolic profiling has shown to be potential diagnostic tool to understand the disease.

OBJECTIVE

The present experiment was designed as a single center observational pilot study to classify and create diagnostic metabolic signatures associated with the energetics of congenital heart disease in cyanotic and acyanotic groups.

METHODS

Metabolic sera profiles were obtained from 35 patients with cyanotic congenital heart disease (TOF) and 23 patients with acyanotic congenital heart disease (ASD and VSD) using high resolution 1D ¹H NMR spectra. Univariate and multivariate statistical analysis were performed to classify particular metabolic disorders associated with cyanotic and acyanotic heart disease.

RESULTS

The results show dysregulations in several metabolites in cyanotic CHD patients versus acyanotic CHD patients. The discriminatory metabolites were further analyzed with area under receiver operating characteristic (AUROC) curve and identified four metabolic entities (i.e. mannose, hydroxyacetone, myoinositol, and creatinine) which could differentiate cyanotic CHDs from acyanotic CHDs with higher specificity.

CONCLUSION

An untargeted metabolic approach proved to be helpful for the detection and distinction of disease-causing metabolites in cyanotic patients from acyanotic ones and can be useful for designing better and personalized treatment protocol.

Macroalgae Specialized Metabolites: Evidence for Their Anti-Inflammatory Health Benefits

Inflammation is an organism's response to chemical or physical injury. It is split into acute and chronic inflammation and is the last, most significant cause of death worldwide. Nowadays, according to the World Health Organization (WHO), the greatest threat to human health is chronic disease. Worldwide, three out of five people die from chronic inflammatory diseases such as stroke, chronic respiratory diseases, heart disorders, and cancer. Nowadays, anti-inflammatory drugs (steroidal and non-steroidal, enzyme inhibitors that are essential in the inflammatory process, and receptor antagonists, among others) have been considered as promising treatments to be explored. However, there remains a significant proportion of patients who show poor or incomplete responses to these treatments or experience associated severe side effects. Seaweeds represent a valuable resource of bioactive compounds associated with anti-inflammatory effects and offer great potential for the development of new anti-inflammatory drugs. This review presents an overview of specialized metabolites isolated from seaweeds with in situ and in vivo anti-inflammatory properties. Phlorotannins, carotenoids, sterols, alkaloids, and polyunsaturated fatty acids present significant anti-inflammatory effects given that some of them are involved directly or indirectly in several inflammatory pathways. The majority of the isolated compounds inhibit the pro-inflammatory mediators/cytokines. Studies have suggested an excellent selectivity of chromene nucleus towards inducible pro-inflammatory COX-2 than its constitutive isoform COX-1. Additional research is needed to understand the mechanisms of action of seaweed's compounds in inflammation, given the production of sustainable and healthier anti-inflammatory agents.

Integrated proteomics and metabolomics analysis of lumbar in a rat model of osteoporosis treated with Gushukang capsules

BACKGROUND

Gushukang (GSK) capsules are a Chinese patented medicine that is widely used in clinics for the treatment of osteoporosis (OP). Animal experiments have revealed that the bone mineral density of osteoporotic rats increase after treatment with GSK capsules. However, the specific mechanism and target of GSK in the treatment of osteoporosis are unclear. Further studies are needed.

METHODS

Metabolomics (GC/MS) and proteomics (TMT-LC-MC/MC) with bioinformatics (KEGG pathway enrichment), correlation analysis (Pearson correlation matrix), and joint pathway analysis (MetaboAnalyst) were employed to determine the underlying mechanisms of GSK. The differential expression proteins were verified by WB experiment.

RESULTS

The regulation of proteins, i.e., Cant1, Gstz1, Aldh3b1, Bid, and Slc1a3, in the common metabolic pathway of differential proteins and metabolites between GSK/OP and OP/SHAM was corrected in the GSK group. The regulation of 12 metabolites (tyramine, thymidine, deoxycytidine, cytosine, L-Aspartate, etc.) were differential in the common enrichment metabolic pathway between GSK /OP and OP/SHAM. Differential proteins and metabolites jointly regulate 11 metabolic pathways, such as purine metabolism, pyrimidine metabolism, histidine metabolism, beta-alanine metabolism, and so on.

CONCLUSION

GSK may protect bone metabolism in osteoporotic rats by affecting nucleotide metabolism, amino acid metabolism, and the immune system.

Associations of plasma omega-3 and omega-6 pufa levels with arterial elasticity: the multi-ethnic study of atherosclerosis

BACKGROUND

Literature examining the relationship of circulating omega-3 and omega-6 polyunsaturated fatty acids [n-3(ω-3) and n-6 (ω-6) PUFAs] and arterial elasticity in large cohort-based populations are lacking. We investigated the association of circulating ω-3and ω-6 PUFAs with large artery elasticity (LAE) and small artery elasticity (SAE) in participants from the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

A total of 6124 participants (mean age 61.9; 52% female; 38% White, 27% Black, 22% Hispanic, and 13% Chinese-American) with plasma phospholipid PUFAs and arterial elasticity measured at baseline were included. LAE and SAE were derived from pulse contour analysis of the radial artery in all subjects in a supine position using tonometry. Linear regression models were used to determine associations for levels of (1) each circulating fatty acid, (2) total ω-3PUFAs, and (3) total ω-6 PUFAs with log-transformed LAE and SAE.

RESULTS

Each standard deviation (SD) increment in circulating levels of total ω-3 PUFAs, eicosapentaenoic acid, and docosahexaenoic acid were associated with a 0.017 ml/mmHg, 0.017 ml/mmHg, and 0.015 ml/mmHg higher LAE respectively (p values all <0.01). No significant trends were observed for ω-3 PUFAs levels with SAE.22 Similarly, no significant trends were observed for ω-6 PUFA levels with either LAE or SAE.

CONCLUSIONS

In a multi-ethnic cohort of individuals free of baseline cardiovascular disease, higher plasma levels of total and individual ω-3 PUFAs were associated with an increased LAE. Further understanding into differential associations of ω-6 PUFAs with LAE and SAE is needed.

IL-17D affects the chemokines and chemokine receptors of intestinal epithelial cells under hyperoxia

IL-17D is a new member of the IL-17 family. Currently, it is believed that IL-17D can directly act on immune cells or may indirectly modulate immune responses by regulating cytokine expression. Herein, we hypothesized that IL-17D regulates the expression of chemokines in intestinal epithelial cells, in turn modulating the immune response within intestinal mucosa under hyperoxia. To explore this notion, newborn rats were divided into a hyperoxia group (85 % O₂) and control group (21 % O₂). Small intestinal tissues were obtained from neonatal rats at 3, 7, 10, and 14 days. Similarly, intestinal epithelial cells were treated by hyperoxia (85 % O₂) as the hyperoxia group or were incubated under normal oxygen (21 % O₂) as the control group. Finally, intestinal epithelial cells subjected to hyperoxia were treated with recombinant IL-17D and IL-17D antibodies for 24, 48, and 72 h. Immunohistochemistry, western blot, and reverse transcription-quantitative polymerase chain reaction were used to detect the expression levels of chemokines and chemokine receptors in intestinal tissues of newborn rats and intestinal epithelial cells. We found that hyperoxia affected chemokine expression both in vivo and in vitro. Under hyperoxia, IL-17D promoted the expression of CCL2, CCL25, CCL28, and CCR9 in intestinal epithelial cells while downregulating CCR2, CCR5, CCL5, and CCL20. Our findings provide a basis for further study on the effects of hyperoxia-induced intestinal inflammation and intestinal injury.

Multi-omics research strategies in ischemic stroke: A multidimensional perspective

Ischemic stroke (IS) is a multifactorial and heterogeneous neurological disorder with high rate of death and long-term impairment. Despite years of studies, there are still no stroke biomarkers for clinical practice, and the molecular mechanisms of stroke remain largely unclear. The high-throughput omics approach provides new avenues for discovering biomarkers of IS and explaining its pathological mechanisms. However, single-omics approaches only provide a limited understanding of the biological pathways of diseases. The integration of multiple omics data means the simultaneous analysis of thousands of genes, RNAs, proteins and metabolites, revealing networks of interactions between multiple molecular levels. Integrated analysis of multi-omics approaches will provide helpful insights into stroke pathogenesis, therapeutic target identification and biomarker discovery. Here, we consider advances in genomics, transcriptomics, proteomics and metabolomics and outline their use in discovering the biomarkers and pathological mechanisms of IS. We then delineate strategies for achieving integration at the multi-omics level and discuss how integrative omics and systems biology can contribute to our understanding and management of IS.

The effect of omega-3 fatty acids on active periodontal therapy: A systematic review and meta-analysis

AIM

"Host modulatory therapy" (HMT) with ω-3 fatty acids aims at reducing inflammation. With HMT as an adjunct, a better result of periodontal therapy is expected. The aim of this systematic review and meta-analysis (MA) was to examine the additional effect of ω-3 fatty acids to non-surgical periodontal therapy (SRP) on the probing pocket depth (PPD) and the clinical attachment level (CAL).

MATERIALS AND METHODS

MEDLINE-PubMed and Cochrane-CENTRAL libraries were searched up to January 2021 for randomized controlled trials in patients with chronic periodontitis, treated with SRP/placebo as controls and SRP/ω-3 fatty acids as the test group.

RESULTS

The search identified 173 unique abstracts, and screening resulted in 10 eligible publications. Descriptive analysis showed a significant effect on the PPD and CAL in favour of the groups with ω-3 fatty acids in the majority of comparisons. MA revealed that adjunctive use of ω-3 fatty acids to SRP resulted in 0.39 mm more PPD reduction (95% CI: -0.58; -0.21) and 0.41 mm more CAL gain (95% CI: -0.63; -0.19) than SRP alone.

CONCLUSIONS

In patients with periodontitis, dietary supplementation with ω-3 fatty acids as an adjunct to SRP is more effective in reducing the PPD and improving the CAL than SRP alone. If SRP is indicated, the use of ω-3 fatty acids can be considered for a moderate extra added effect on PPD reduction and CAL gain. The strength of this recommendation is moderate.

Impact of health and lifestyle food supplements on periodontal tissues and health

According to the new classification, periodontitis is defined as a chronic multifactorial inflammatory disease associated with dysbiotic biofilms and characterized by progressive destruction of the tooth-supporting apparatus. This definition, based on the current scientific evidence, clearly indicates and emphasizes, beside the microbial component dental biofilm, the importance of the inflammatory reaction in the progressive destruction of periodontal tissues. The idea to modulate this inflammatory reaction in order to decrease or even cease the progressive destruction was, therefore, a logical consequence. Attempts to achieve this goal involve various kinds of anti-inflammatory drugs or medications. However, there is also an increasing effort in using food supplements or so-called natural food ingredients to modulate patients' immune responses and maybe even improve the healing of periodontal tissues. The aim of this chapter of Periodontology 2000 is to review the evidence of various food supplements and ingredients regarding their possible effects on periodontal inflammation and wound healing. This review may help researchers and clinicians to evaluate the current evidence and to stimulate further research in this area.

The Potential of the Mediterranean Diet to Improve Mitochondrial Function in Experimental Models of Obesity and Metabolic Syndrome

The abnormal expansion of body fat paves the way for several metabolic abnormalities including overweight, obesity, and diabetes, which ultimately cluster under the umbrella of metabolic syndrome (MetS). Patients with MetS are at an increased risk of cardiovascular disease, morbidity, and mortality. The coexistence of distinct metabolic abnormalities is associated with the release of pro-inflammatory adipocytokines, as components of low-to-medium grade systemic inflammation and increased oxidative stress. Adopting healthy lifestyles, by using appropriate dietary regimens, contributes to the prevention and treatment of MetS. Metabolic abnormalities can influence the function and energetic capacity of mitochondria, as observed in many obesity-related cardio-metabolic disorders. There are preclinical studies both in cellular and animal models, as well as clinical studies, dealing with distinct nutrients of the Mediterranean diet (MD) and dysfunctional mitochondria in obesity and MetS. The term “Mitochondria nutrients” has been adopted in recent years, and it depicts the adequate nutrients to keep proper mitochondrial function. Different experimental models show that components of the MD, including polyphenols, plant-derived compounds, and polyunsaturated fatty acids, can improve mitochondrial metabolism, biogenesis, and antioxidant capacity. Such effects are valuable to counteract the mitochondrial dysfunction associated with obesity-related abnormalities and can represent the beneficial feature of polyphenols-enriched olive oil, vegetables, nuts, fish, and plant-based foods, as the main components of the MD. Thus, developing mitochondria-targeting nutrients and natural agents for MetS treatment and/or prevention is a logical strategy to decrease the burden of disease and medications at a later stage. In this comprehensive review, we discuss the effects of the MD and its bioactive components on improving mitochondrial structure and activity.

The Increase in the Drug Resistance of Acute Myeloid Leukemia THP-1 Cells in High-Density Cell Culture Is Associated with Inflammatory-like Activation and Anti-Apoptotic Bcl-2 Proteins

It is known that cell culture density can modulate the drug resistance of acute myeloid leukemia (AML) cells. In this work, we studied the drug sensitivity of AML cells in high-density cell cultures (cell lines THP-1, HL-60, MV4-11, and U937). It was shown that the AML cells in high-density cell cultures in vitro were significantly more resistant to DNA-damaging drugs and recombinant ligand izTRAIL than those in low-density cell cultures. To elucidate the mechanism of the increased drug resistance of AML cells in high-density cell cultures, we studied the activation of Bcl-2, Hif-1alpha, and NF-kB proteins, as well as cytokine secretion, the inflammatory immunophenotype, and the transcriptome for THP-1 cells in the low-density and high-density cultures. The results indicated that the increase in the drug resistance of proliferating THP-1 cells in high-density cell cultures was associated with the accumulation of inflammatory cytokines in extracellular medium, and the formation of NF-kB-dependent inflammatory-like cell activation with the anti-apoptotic proteins Bcl-2 and Bcl-xl. The increased drug resistance of THP-1 cells in high-density cultures can be reduced by ABT-737, an inhibitor of Bcl-2 family proteins, and by inhibitors of NF-kB. The results suggest a mechanism for increasing the drug resistance of AML cells in the bone marrow and are of interest for developing a strategy to suppress this resistance.

Chronic social defeat stress increases the amounts of 12-lipoxygenase lipid metabolites in the nucleus accumbens of stress-resilient mice

Severe and prolonged social stress induces mood and cognitive dysfunctions and precipitates major depression. Neuroinflammation has been associated with chronic stress and depression. Rodent studies showed crucial roles of a few inflammation-related lipid mediators for chronic stress-induced depressive-like behaviors. Despite an increasing number of lipid mediators identified, systematic analyses of synthetic pathways of lipid mediators in chronic stress models have not been performed. Using LC–MS/MS, here we examined the effects of chronic social defeat stress on multiple synthetic pathways of lipid mediators in brain regions associated with stress susceptibility in mice. Chronic social defeat stress increased the amounts of 12-lipoxygenase (LOX) metabolites, 12-HETE and 12-HEPE, specifically in the nucleus accumbens 1 week, but not immediately, after the last stress exposure. The increase was larger in stress-resilient mice than stress-susceptible mice. The S isomer of 12-HETE was selectively increased in amount, indicating the role of 12S-LOX activity. Among the enzymes known to have 12S-LOX activity, only Alox12 mRNA was reliably detected in the brain and enriched in brain endothelial cells. These findings suggest that chronic social stress induces a late increase in the amounts of 12S-LOX metabolites derived from the brain vasculature in the nucleus accumbens in a manner associated with stress resilience.

Effect of dietary n-6: n-3 Poly-Unsaturated fatty acids ratio on gestational diabetes mellitus: a prospective cohort

OBJECTIVE

The aim of this study was to investigate the relationship between dietary n-6: n-3 poly-unsaturated fatty acids (PUFA) ratio and the risk of developing gestational diabetes mellitus (GDM).

MATERIALS AND METHODS

A total of 100 pregnant women were prospectively included for detailed information on dietary intake at 16-18 weeks evaluated using a three-day food record, and subsequent GDM diagnosis at 24-28 weeks. Participants were divided into two groups for analysis: GDM group (n = 22) and control group (n = 78) based on oral glucose tolerance test results performed between 24 and 28 weeks.

RESULTS

The average dietary n-6: n-3 PUFA ratio in the control group was 5.63 ± 2.12 and that in the GDM group was 8.35 ± 3.45, within a significant difference (p < .05). A significant difference was associated with a higher dietary n-6: n-3 PUFA ratio and GDM (adjusted odds ratio = 4.29, 95%confidence interval:1.303, 14.124).

CONCLUSIONS

Higher dietary n-6: n-3 PUFA ratio was associated with higher odds of GDM. Given the small sample, further studies are required to confirm this hypothesis.

Qing-Wen-Jie-Re Mixture Ameliorates Poly (I:C)-Induced Viral Pneumonia Through Regulating the Inflammatory Response and Serum Metabolism

Qing-Wen-Jie-Re mixture (QWJR) has been used in the treatment of the coronavirus disease 2019 (COVID-19) in China. However, the protective mechanisms of QWJR on viral pneumonia remain unclear. In the present study, we first investigated the therapeutic effects of QWJR on a rat viral pneumonia model established by using polyinosinic-polycytidylic acid (poly (I:C)). The results indicated that QWJR could relieve the destruction of alveolar-capillary barrier in viral pneumonia rats, as represented by the decreased wet/dry weight (W/D) ratio in lung, total cell count and total protein concentration in bronchoalveolar lavage fluid (BALF). Besides, QWJR could also down-regulate the expression of inflammatory factors such as tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β and IL-6. More M1-type macrophage polarization was detected by calculating CD86⁺ cells and CD206⁺ cells and validated by the decline of inducible nitric oxide synthase (iNOS) and elevated arginase-1 (Arg-1) in lung. Finally, serum untargeted metabolomics analysis demonstrated that QWJR might take effect through regulating arginine metabolism, arachidonic acid (AA) metabolism, tricarboxylic acid (TCA) cycle, nicotinate and nicotinamide metabolism processes.

Progress in enrichment of n-3 polyunsaturated fatty acid: a review

n-3 Polyunsaturated fatty acids (n-3 PUFA) has been widely used in foods, and pharmaceutical products due to its beneficial effects. The content of n-3 PUFA in natural oils is usually low, which decreases its added value. Thus, there is an increasing demand on the market for n-3 PUFA concentrates. This review firstly introduces the differences in bioavailability and oxidative stability between different types of PUFA concentrate (free fatty acid, ethyl ester and acylglycerol), and then provides a comprehensive discussion of different methods for enrichment of lipids with n-3 PUFA including physical-chemical methods and enzymatic methods. Lipases used for catalyzing esterification, transesterification and hydrolysis reactions play an important role in the production of highly enriched various types of n-3 PUFA concentrates. Lipase-catalyzed alcoholysis or hydrolysis reactions are the mostly employed method to prepare high-quality n-3 PUFA of structural acylglycerols. Although many important advantages offered by lipases in enrichment of n-3 PUFA, the high cost of enzyme limits its industrial-scale production. Further research should focus on looking for biological enzymes with extraordinary catalytic ability and clear selectivity. Other novel technologies such as protein engineering and immobilization may be needed to modify lipases to improve its selectivity, catalytic ability and reuse.

Crohn's Disease and Female Infertility: Can Nutrition Play a Supporting Role?

Crohn's disease (CD) is a chronic inflammatory disease (IBD) that can affect the entire gastrointestinal tract in a non-continuous mode. CD is generally diagnosed most commonly between 15 and 35 years of age and may affect female fertility. The role of diet in supporting wellbeing outcome and reproductive potential in women is well-known; however, no effective efforts have been made to improve women's awareness in CD. Our review aims to describe the burden of CD on women's fertility, reporting the most relevant nutrients that support reproductive function to ensure women diagnosed with IBD an adequate health-related quality of life.

Associations of Vitamin B6 Intake and Plasma Pyridoxal 5'-Phosphate with Plasma Polyunsaturated Fatty Acids in US Older Adults: Findings from NHANES 2003-2004

Previous evidence suggests a potential dual impact of aging and vitamin B6 (B6) deficiency on polyunsaturated fatty acid (PUFA) metabolism; gender may influence PUFA biosynthesis. Perturbation of PUFA compositions during B6 deficiency could be linked to age-related health outcomes. However, little is known about the interrelationships between vitamin B6, PUFA, and gender in the older population. Therefore, we investigated whether gender-specific associations of B6 intake and plasma pyridoxal 5’-phosphate (PLP) concentration, respectively, with plasma PUFA concentrations and ratios (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), EPA + DHA, EPA/AA, and (EPA + DHA)/AA) existed in older adults. We further examined the relationships of adequate B6 status (PLP ≥ 20 nmol/L) with high (above median) plasma PUFA relative to deficient B6 status. This cross-sectional study analyzed 461 participants aged ≥60 years from NHANES 2003−2004. Nutrient intakes were assessed using two 24-h recalls and supplement questionnaires. PLP and PUFA concentrations were measured. Multivariate linear regression assessed the association of B6 intake and PLP with PUFA; multivariate logistic regression evaluated the relationship of adequate B6 status with high plasma PUFA, adjusting for demographic, socioeconomic, and dietary factors; physical activity; smoking; alcohol; medication; and BMI. There were interactions between gender and B6 intake on EPA (P-interaction = 0.008) and AA (P-interaction = 0.004) only, whereas no interaction existed between gender and PLP on PUFA. PLP was directly associated with EPA (β = 0.181, P = 0.002), DHA (β = 0.109, P = 0.005), EPA + DHA (β = 0.14, P = 0.002), EPA/AA (β = 0.186, P = 0.004), and (EPA + DHA)/AA (β = 0.13, P = 0.026). The odds of having high plasma EPA (adjusted (a) OR: 2.03, P = 0.049) and EPA/AA (aOR: 3.83, P < 0.0001) were greater in those with adequate B6 status compared to those with deficient B6 status. In conclusion, in US older adults, a higher PLP level was associated with a greater level of EPA, DHA, EPA + DHA, EPA/AA, and (EPA + DHA)/AA. Adequate B6 status was associated with high EPA and EPA/AA status. These findings suggest that sufficient vitamin B6 status may positively influence PUFA metabolism in older adults.

Lipid metabolism and endometrial receptivity

BACKGROUND

Obesity has now been recognized as a high-risk factor for reproductive health. Although remarkable advancements have been made in ART, a considerable number of infertile obese women still suffer from serial implantation failure, despite the high quality of embryos transferred. Although obesity has long been known to exert various deleterious effects on female fertility, the underlying mechanisms, especially the roles of lipid metabolism in endometrial receptivity, remain largely elusive.

OBJECTIVE AND RATIONALE

This review summarizes current evidence on the impacts of several major lipids and lipid-derived mediators on the embryonic implantation process. Emerging methods for evaluating endometrial receptivity, for example transcriptomic and lipidomic analysis, are also discussed.

SEARCH METHODS

The PubMed and Embase databases were searched using the following keywords: (lipid or fatty acid or prostaglandin or phospholipid or sphingolipid or endocannabinoid or lysophosphatidic acid or cholesterol or progesterone or estrogen or transcriptomic or lipidomic or obesity or dyslipidemia or polycystic ovary syndrome) AND (endometrial receptivity or uterine receptivity or embryo implantation or assisted reproductive technology or in vitro fertilization or embryo transfer). A comprehensive literature search was performed on the roles of lipid-related metabolic pathways in embryo implantation published between January 1970 and March 2022. Only studies with original data and reviews published in English were included in this review. Additional information was obtained from references cited in the articles resulting from the literature search.

OUTCOMES

Recent studies have shown that a fatty acids-related pro-inflammatory response in the embryo-endometrium boundary facilitates pregnancy via mediation of prostaglandin signaling. Phospholipid-derived mediators, for example endocannabinoids, lysophosphatidic acid and sphingosine-1-phosphate, are associated with endometrial receptivity, embryo spacing and decidualization based on evidence from both animal and human studies. Progesterone and estrogen are two cholesterol-derived steroid hormones that synergistically mediate the structural and functional alterations in the uterus ready for blastocyst implantation. Variations in serum cholesterol profiles throughout the menstrual cycle imply a demand for steroidogenesis at the time of window of implantation (WOI). Since 2002, endometrial transcriptomic analysis has been serving as a diagnostic tool for WOI dating. Numerous genes that govern lipid homeostasis have been identified and, based on specific alterations of lipidomic signatures differentially expressed in WOI, lipidomic analysis of endometrial fluid provides a possibility for non-invasive diagnosis of lipids alterations during the WOI.

WIDER IMPLICATIONS

Given that lipid metabolic dysregulation potentially plays a role in infertility, a better understanding of lipid metabolism could have significant clinical implications for the diagnosis and treatment of female reproductive disorders.

Defining Fatty Acid Changes Linked to Rumen Development, Weaning and Growth in Holstein-Friesian Heifers

After birth, as effectively monogastric animals, calves undergo substantial physiological changes to become ruminants by 3 months of age and reach sexual maturity at approximately 15 months of age. Herein, we assess longitudinal metabolomic changes in Holstein-Friesian (HF) heifers from birth until sexual maturity during this developmental process. Sera from 20 healthy, HF heifers were sampled biweekly from 2 weeks of age until 13 months of age and then monthly until 19 months of age. Sera were assessed using flow infusion electrospray high-resolution mass spectrometry (FIE-HRMS) on a Q Exactive hybrid quadrupole-Orbitrap mass spectrometer for high-throughput, sensitive, non-targeted metabolite fingerprinting. Partial least squares discriminant analysis (PLS-DA) and unsupervised hierarchical clustering analysis (HCA) of the derived metabolomes indicated changes detectable in heifers’ sera over time. Time series analyses identified 30 metabolites that could be related to rumen development and weaning at ~3 months of age. Further time series analysis identified 40 metabolites that could be correlated with growth. These findings highlight the role of acetic acid and 3-phenylpropionate (3-PP) in rumen development and growth, suggest that weaning induces elevated levels of fatty acyls in response to a post-weaning stress-induced innate immune response and demonstrate the utilization of fatty acyls in growth. The identified metabolites offer serum metabolites which could inform the nutrition and healthy development of heifers.

Role of omega-3 polyunsaturated fatty acids, citrus pectin, and milk-derived exosomes on intestinal barrier integrity and immunity in animals

The gastrointestinal tract of livestock and poultry is prone to challenge by feedborne antigens, pathogens, and other stress factors in the farm environment. Excessive physiological inflammation and oxidative stress that arises firstly disrupts the intestinal epithelial barrier followed by other components of the gastrointestinal tract. In the present review, the interrelationship between intestinal barrier inflammation and oxidative stress that contributes to the pathogenesis of inflammatory bowel disease was described. Further, the role of naturally existing immunomodulatory nutrients such as the omega-3 polyunsaturated fatty acids, citrus pectin, and milk-derived exosomes in preventing intestinal barrier inflammation was discussed. Based on the existing evidence, the possible molecular mechanism of these bioactive nutrients in the intestinal barrier was outlined for application in animal diets.

Blood levels of omega-6 fatty acids and coronary heart disease: a systematic review and metaanalysis of observational epidemiology

Individual omega-6 polyunsaturated fatty acids (PUFAs), principally linoleic acid (LA) and arachidonic acid (AA), may have differential impacts on cardiovascular risk. We aimed to summarize the up-to-date epidemiology evidence on the relationship between blood levels of omega-6 PUFAs and the risk of coronary heart disease (CHD). Population-based studies determining PUFA levels in blood were identified until May 2021 in PubMed, Embase, Web of Science, and Cochrane Library. Random-effects meta-analyses of cohorts comparing the highest versus lowest category were conducted to combine study-specific risk ratios (RRs) with 95% confidence intervals (CIs). Blood levels of omega-6 PUFAs were compared between the CHD case and non-case, presented as a weight mean difference (WMD). Twenty-one cohorts and eleven case-control studies were included. The WMD was -0.71 (95% CI: -1.20, -0.21) for LA and 0.08 (95% CI: -0.28, 0.43) for AA. LA levels were inversely associated with total CHD risk (RR: 0.85, 95% CI: 0.71, 1.00), but not AA. Each one-SD increase in LA levels resulted in 10% reductions in the risk of fatal CHD (RR: 0.90, 95% CI: 0.86, 0.95), but not in non-fatal CHD. Such findings highlight that the current recommendation for optimal intakes of omega-6 PUFAs (most LA) may offer a coronary benefit in primary prevention.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2056867 .

Dietary plant oil supplemented with arachidonic acid and eicosapentaenoic acid affects the fatty acid composition and eicosanoid metabolism of Atlantic salmon (Salmo salar L.) during smoltification

This study sought to investigate whether a "natural diet" (mimicking the fatty acid composition of freshwater aquatic insects eaten by salmon parr) during the freshwater (FW) life stage of pre-smolt Atlantic salmon (Salmo salar L.) affected red blood cells and gill fatty acid composition as well as eicosanoid metabolism in gill during smolting at different temperatures. Before being transferred to seawater (SW), salmon parr were fed with a modified (MO) diet containing vegetable oils (rapeseed, palm, and linseed oils) supplemented with eicosapentaenoic acid (EPA) and arachidonic acid (ARA) to completely replace the fish oil (FO). Fatty acid composition in red blood cells and gill tissues was determined before SW transfer and six weeks after. Additionally, the expression of genes associated with eicosanoid metabolism and Na⁺/K⁺-ATPase (NKA) activity in salmon gill was examined at different temperatures before SW transfer and 24 h after. The results showed the changes in fatty acid composition, including sum monounsaturated fatty acids (MUFAs), docosahexaenoic acid (DHA), ARA, EPA, and sum n-6 polyunsaturated fatty acids (n-6 PUFA) in both red blood cells and gill tissues at the FW stage were consistent with the fatty acid profiles of the supplied MO and FO fish diets; however sum EPA and DHA composition exhibited opposite trends to those of the FO diet. The proportion of ARA, EPA, and n-6 PUFA increased, whereas sum MUFAs and DHA decreased in the red blood cells and gill tissues of MO-fed fish compared to those fed with the FO diet at FW stage. Additionally, 5-lipoxygenase-activating protein (Flap) expression was downregulated in MO-fed fish prior to SW transfer. During the process of SW transfer at different temperatures, the MO diet remarkably suppressed NKAα1a expression in MO-fed fish both at 12 and 16 °C. The MO diet also upregulated phospholipase A2 group IV (PLA2g4) expression in gills at 8, 12, and 16 °C, but suppressed phospholipase A2 group VI (PLA2g6) expression in gills at 12 °C compared to FO-fed fish at 12 °C and MO-fed fish at 8 °C. The MO diet also upregulated Cyclooxygenase 2 (Cox-2) expression at 8 °C compared to FO-fed fish and increased Arachidonate 5-lipoxygenase (5-Lox) expression in MO-fed fish at 16 °C compared to both FO-fed fish at 16 °C and MO-fed fish at 8 °C. Our study also determined that both SW transfer water temperatures and diets during the FW period jointly influenced the mRNA expression of PLA2g4, PLA2g6, and Lpl, whereas 5-Lox was more sensitive to dietary changes. In conclusion, the MO diet affected the fatty acid composition in gill and in red blood cells. When transferred to SW, dietary ARA supplementation could promote the bioavailability for eicosanoid synthesis in gill mainly via PLA2g4 activation, and potentially inhibit the stress and inflammatory response caused by different water temperatures through dietary EPA supplementation.

Therapeutic Effects of Berberine on Liver Fibrosis are associated With Lipid Metabolism and Intestinal Flora

Liver cirrhosis is a form of liver fibrosis resulting from chronic hepatitis caused by various liver diseases, such as viral hepatitis, alcoholic liver damage, nonalcoholic steatohepatitis, autoimmune liver disease, and by parasitic diseases such as schistosomiasis. Liver fibrosis is the common pathological base and precursors of cirrhosis. Inflammation and disorders of lipid metabolism are key drivers in liver fibrosis. Studies have determined that parts of the arachidonic acid pathway, such as its metabolic enzymes and biologically active products, are hallmarks of inflammation, and that aberrant peroxisome proliferator-activated receptor gamma (PPARγ)-mediated regulation causes disorders of lipid metabolism. However, despite the ongoing research focus on delineating the mechanisms of liver fibrosis that underpin various chronic liver diseases, effective clinical treatments have yet to be developed. Berberine (BBR) is an isoquinoline alkaloid with multiple biological activities, such as anti-inflammatory, anti-bacterial, anti-cancer, and anti-hyperlipidemic activities. Many studies have also found that BBR acts via multiple pathways to alleviate liver fibrosis. Furthermore, the absorption of BBR is increased by nitroreductase-containing intestinal flora, and is strengthened via crosstalk with bile acid metabolism. This improves the oral bioavailability of BBR, thereby enhancing its clinical utility. The production of butyrate by intestinal anaerobic bacteria is dramatically increased by BBR, thereby amplifying butyrate-mediated alleviation of liver fibrosis. In this review, we discuss the effects of BBR on liver fibrosis and lipid metabolism, particularly the metabolism of arachidonic acid, and highlight the potential mechanisms by which BBR relieves liver fibrosis through lipid metabolism related and intestinal flora related pathways. We hope that this review will provide insights on the BBR-based treatment of liver cirrhosis and related research in this area, and we encourage further studies that increase the ability of BBR to enhance liver health.

Uncovering the Potential of Lipid Drugs: A Focus on Transient Membrane Microdomain-Targeted Lipid Therapeutics

Membrane lipids are generally viewed as inert physical barriers, but many vital cellular processes greatly rely on the interaction with these structures, as expressed by the membrane hypothesis that explain the genesis of schizophrenia, Alzheimer's and autoimmune diseases, chronic fatigue or cancer, among others. The concept that the cell membrane displays transient membrane microdomains with distinct lipid composition provide the basis for the development of selective lipid-targeted therapies, the membrane-lipid therapies (MLTs). In this concern, medicinal chemists may design therapeutically valuable compounds 1) with a higher affinity for the lipids in these microdomains to restore the normal physiological conditions, 2) that can directly or 3) indirectly (via enzyme inhibition/activation) replace damaged lipids or restore the regular lipid levels in the whole membrane or microdomain, 4) that alter the expression of genes related to lipid genesis/metabolism or 5) that modulate the pathways related to the membrane binding affinity of lipid-anchored proteins. In this context, this mini-review aims to explore the structural diversity and clinical applications of some of the main membrane and microdomain-targeted lipid drugs.

Egg-Phosphatidylcholine Attenuates T-Cell Dysfunction in High-Fat Diet Fed Male Wistar Rats

Obesity is associated with immune dysfunction including an impaired T-cell function characterized by a lower IL-2 (proliferation marker) production after stimulation. Phosphatidylcholine (PC), a form of choline mostly found in eggs, has been shown to beneficially modulate T-cell responses during the lactation period by increasing the production of IL-2. To determine the impact of egg-PC as part of a high-fat diet on immune function we randomly fed male Wistar rats one of three diets containing the same amount of total choline but differing in the form of choline: 1-Control low fat [CLF, 10% wt/wt fat, 100% free choline (FC)]; 2- Control high-fat (CHF, 25% wt/wt fat, 100% FC); 3- PC high-fat (PCHF, 25% wt/wt, 100% PC). After 9 weeks of feeding, rats were euthanized. Cell phenotypes and ex vivo cytokine production by splenocytes stimulated with phorbol 12-myristate 13-acetate plus ionomycin (PMA+I), lipopolysaccharide (LPS) and pokeweed (PWM) were measured by flow cytometry and ELISA, respectively. Rats fed the PCHF diet had a lower proportion of CD3+ cells when compared to both the CLF and the CHF. Following PMA+I stimulation, splenocytes from the CHF group produced less IL-2 and TNF-α compared to CLF and PCHF groups. No significant differences in cytokine production were found among groups after LPS and PWM stimulation. Our results show that feeding a high-fat diet impairs T-cell responses, as measured by ex vivo cytokine production, which can be attenuated by providing egg-PC.

n-3 polyunsaturated fatty acids in the regulation of adipose tissue browning and thermogenesis in obesity: Potential relationship with gut microbiota

BACKGROUND

Obesity is a worldwide public health problem characterized by fat tissue accumulation, favouring adipose tissue and metabolic alterations. Increasing energy expenditure (EE) through brown adipose tissue activation and white adipose tissue (WAT) browning has gained relevance as a therapeutic approach. Different bioactive compounds, such as n-3 polyunsaturated fatty acids (PUFA), have been shown to induce those thermogenic effects. This process is regulated by the gut microbiota as well. Nevertheless, obesity is characterized by gut microbiota dysbiosis, which can be restored by weight loss and n-3 PUFA intake, among other factors. Knowledge gap: However, the role of the gut microbiota on the n-3 PUFA effect in inducing thermogenesis in obesity has not been fully elucidated.

OBJECTIVE

This review aims to elucidate the potential implications of this interrelation on WAT browning adiposw sittue (BAT), BAT activity, and EE regulation in obesity models.

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.

Dietary intake and plasma concentrations of PUFAs in childhood and adolescence in relation to asthma and lung function up to adulthood

BACKGROUND

PUFAs may influence the risk of asthma; however, long-term prospective studies including objective biomarkers of PUFA intake are lacking.

OBJECTIVES

The objective was to investigate the role of dietary intake and plasma concentrations of n-3 and n-6 (ω-3 and ω-6) PUFAs in childhood and adolescence for the development of asthma and lung function up to young adulthood.

METHODS

The study included participants from the Swedish prospective birth cohort BAMSE. Dietary intake of PUFAs was calculated from FFQs (n = 1992) and plasma proportions of PUFAs were measured in phospholipids (n = 831). We analyzed the n-3 PUFA α-linolenic acid (ALA; 18:3n-3); the sum of very-long-chain (VLC) n-3 PUFAs: EPA (20:5n-3), DHA (22:6n-3), and docosapentaenoic acid (22:5n-3); and the n-6 PUFAs linoleic acid (LA; 18:2n-6) and arachidonic acid (AA; 20:4n-6). Asthma was assessed by questionnaires at 8, 16, and 24 y and lung function was measured by spirometry at 24 y.

RESULTS

A high (≥median) self-reported dietary intake of LA at 8 y and AA at 16 y was associated with increased risk of prevalent asthma at 24 y (OR: 1.41; 95% CI: 1.10, 1.82 and OR: 1.32; 95% CI: 1.02, 1.70, respectively). In contrast, plasma proportions of ALA, ∑VLC n-3 PUFAs, and AA at 8 y, as well as LA at 16 y, were inversely associated with prevalent asthma at 24 y (e.g., OR: 0.55; 95% CI: 0.38, 0.81 for ∑VLC n-3 PUFAs). No consistent associations were observed with lung function.

CONCLUSIONS

High dietary intake of certain n-6 PUFAs in childhood or adolescence may be associated with increased risk of asthma up to young adulthood, whereas dietary biomarkers of certain n-3 and n-6 PUFAs in plasma may be associated with decreased risk. Thus, the role of diet compared with altered metabolism of PUFAs needs further investigation to improve dietary preventive strategies for asthma.

The Impact of Fish Oil Supplementation on Self-Perception of the Voice in Vocal Performers: A Randomized, Single-Blind, Placebo-Controlled Study

PURPOSE

Physically active adults have experienced training benefits from fish oil-derived omega-3 fatty acid (FO n3), which may also be of benefit to singers. The purpose of this research study was to determine if self-reported vocal adaptations and body composition changes occur in singers following FO n3 supplementation in conjunction with a singer's normal training regimen.

METHOD

Twenty college students, currently enrolled in vocal lessons at a university, were randomized to receive either 3.0 g of FO n3 or placebo, which they took during a 10-week study period. Participants were blinded to group assignment. Participants completed the Reflux Symptom Index (RSI), Singing Voice Handicap Index-10 (SVHI-10), and the Evaluation of Ability to Sing Easily (EASE) and submitted to body composition measures (weight, skeletal mass, and body fat mass) before and after the study period.

RESULTS

Sixteen participants completed all parts of the study protocol. Mean compliance for the placebo group (83.9%) and the supplement group (75.2%) was similar. There were no significant differences in body composition measures, RSI scores, and EASE scores between groups. Scores on the SVHI-10 decreased significantly over time for all participants.

CONCLUSIONS

Improvements seen in the SVHI-10 were not meaningfully different between the supplement and placebo group, pointing to the benefit of weekly lessons. The lack of changes in the questionnaire scores in the supplement group are partially attributed to the low compliance rate and low sample size, which is supported by the lack of change in the body composition measures.

Depletion of essential fatty acids in muscle is associated with shorter survival of cancer patients undergoing surgery-preliminary report

Emerging studies are reporting associations between skeletal muscle abnormalities and survival in cancer patients. Cancer prognosis is associated with depletion of essential fatty acids in erythrocytes and plasma in humans. However the relationship between skeletal muscle membrane fatty acid composition and survival is unknown. This study investigates the relationship between fatty acid content of phospholipids in skeletal muscle and survival in cancer patients. Rectus abdominis biopsies were collected during cancer surgery from 35 patients diagnosed with cancer. Thin-layer and gas chromatography were used for quantification of phospholipid fatty acids. Cutpoints for survival were defined using optimal stratification. Median survival was between 450 and 500 days when patients had arachidonic acid (AA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in muscle phospholipid below the cut-point compared to 720-800 days for patients above. Cox regression analysis revealed that low amounts of AA, EPA and DHA are risk factors for death. The risk of death remained significant for AA [HR 3.5 (1.11-10.87), p = 0.03], EPA [HR 3.92 (1.1-14.0), p = 0.04] and DHA [HR 4.08 (1.1-14.6), p = 0.03] when adjusted for sex. Lower amounts of essential fatty acids in skeletal muscle membrane is a predictor of survival in cancer patients. These results warrant investigation to restore bioactive fatty acids in people with cancer.

Predictive serum biomarkers of patients with cerebral infarction

OBJECTIVES

Stroke is the third most common cause of death and also causes seizures and disability. Biomarkers are abnormal signal indicators at the biological level that are present before the organism is seriously affected and are more sensitive to early diagnosis than are traditional imaging methods. Early diagnosis of stroke can prevent the progression of the disease. However, there are currently no widely accepted biomarkers for stroke that have been applied clinically.

METHODS

A serum metabonomics method based on ultra-high-performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry (UPLC-Q-TOF/MS) was used to identify potential biomarkers and metabolic pathways of cerebral infarction. The receiver-operating characteristic (ROC) curve was used to verify the diagnostic and classification abilities of the biomarkers, and a support vector machine (SVM) model was developed for the prediction of cerebral infarction.

RESULTS

Principal component analysis revealed a clear separation between the normal and cerebral infarction groups. A total of 13 potential serum biomarkers were identified, which were mainly involved in linoleic acid metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis; tyrosine metabolism; arachidonic acid metabolism; and fatty acid biosynthesis. The ROC curve analysis showed that the potential biomarkers had high specificity and sensitivity for the diagnosis of cerebral infarction. The SVM model had good diagnostic ability and could accurately distinguish the control group from the cerebral infarction group.

DISCUSSION

The metabonomics approach may be a useful bioanalytical method for understanding the pathophysiology of cerebral infarction and may provide an experimental basis for the development of clinical biomarkers for stroke.