Fatty Acid Classes Research Articles

A high ratio of linoleic acid (n-6 PUFA) to alpha-linolenic acid (n-3 PUFA) adversely affects early stage of human neuronal differentiation and electrophysiological activity of glutamatergic neurons in vitro.

Introduction: There is a growing interest in the possibility of dietary supplementation with polyunsaturated fatty acids (PUFAs) for treatment and prevention of neurodevelopmental and neuropsychiatric disorders. Studies have suggested that of the two important classes of polyunsaturated fatty acids, omega-6 (n-6) and omega-3 (n-3), n-3 polyunsaturated fatty acids support brain development and function, and when used as a dietary supplement may have beneficial effects for maintenance of a healthy brain. However, to date epidemiological studies and clinical trials on children and adults have been inconclusive regarding treatment length, dosage and use of specific n-3 polyunsaturated fatty acids. The aim of this study is to generate a simplified in vitro cell-based model system to test how different n-6 to n-3 polyunsaturated fatty acids ratios affect human-derived neurons activity as a cellular correlate for brain function and to probe the mechanism of their action. Methods: All experiments were performed by use of human induced pluripotent stem cells (iPSCs). In this study, we examined the effect of different ratios of linoleic acid (n-6) to alpha-linolenic acid in cell growth medium on induced pluripotent stem cell proliferation, generation of neuronal precursors and electrophysiology of cortical glutamatergic neurons by multielectrode array (MEA) analysis. Results: This study shows that at a n-6:n-3 ratio of 5:1 polyunsaturated fatty acids induce stem cell proliferation, generating a large increase in number of cells after 72h treatment; suppress generation of neuronal progenitor cells, as measured by decreased expression of FOXG1 and Nestin in neuronal precursor cells (NPC) after 20days of development; and disrupt neuronal activity in vitro, increasing spontaneous neuronal firing, reducing synchronized bursting receptor subunits. We observed no significant differences for neuronal precursor cells treated with ratios 1:3 and 3:1, in comparison to 1:1 control ratio, but higher ratios of n-6 to n-3 polyunsaturated fatty acids adversely affect early stages of neuronal differentiation. Moreover, a 5:1 ratio in cortical glutamatergic neurons induce expression of GABA receptors which may explain the observed abnormal electrophysiological activity.

Metabolomics Biomarkers for Fatty Acid Intake and Biomarker-Calibrated Fatty Acid Associations with Chronic Disease Risk in Postmenopausal Women

BackgroundA substantial observational literature relating specific fatty acid classes to chronic disease risk may be limited by its reliance on self-reported dietary data. ObjectivesWe aimed to develop biomarkers for saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acid densities, and to study their associations with cardiovascular disease (CVD), cancer, and type 2 diabetes (T2D) in Women’s Health Initiative (WHI) cohorts. MethodsBiomarker equations were based primarily on serum and urine metabolomics profiles from an embedded WHI human feeding study (n = 153). Calibration equations were based on biomarker values in a WHI nutritional biomarker study (n = 436). Calibrated intakes were assessed in relation to disease incidence in larger WHI cohorts (n = 81,894). Participants were postmenopausal women, aged 50–79 when enrolled at 40 United States Clinical Centers (1993–1998), with a follow-up period of ∼20 y. ResultsBiomarker equations meeting criteria were developed for SFA, MUFA, and PUFA densities. That for SFA density depended somewhat weakly on metabolite profiles. On the basis of our metabolomics platforms, biomarkers were insensitive to trans fatty acid intake. Calibration equations meeting criteria were developed for SFA and PUFA density, but not for MUFA density. With or without biomarker calibration, SFA density was associated positively with risk of CVD, cancer, and T2D, but with small hazard ratios, and CVD associations were not statistically significant after controlling for other dietary variables, including trans fatty acid and fiber intake. Following this same control, PUFA density was not significantly associated with CVD risk, but there were positive associations for some cancers and T2D, with or without biomarker calibration. ConclusionsHigher SFA and PUFA diets were associated with null or somewhat higher risk for clinical outcomes considered in this population of postmenopausal United States women. Further research is needed to develop even stronger biomarkers for these fatty acid densities and their major components.This study is registered with clinicaltrials.gov identifier: NCT00000611.

Fatty acid profiles of cultured Hippocampus hippocampus trunk muscles and potential nutritional value

Syngnathids (seahorses, pipefishes and seadragons) are an attractive resource for Traditional Chinese Medicine (TCM). Despite few scientific studies supporting seahorse nutritional benefits, they are believed to possess medicinal properties that enhance human health. The European short-snout seahorse Hippocampus hippocampus is classified as Data Deficient by the IUCN Red List of Threatened Species. Nevertheless, there are increasing records of this species being illegally captured and traded to supply TCM. This study investigated the fatty acid (FA) profiles of the trunk muscles of cultured female and male H. hippocampus, to assess sex and intraspecific variation, as well as their potential nutritional value. The contents of crude lipid (4.05 ± 2.15% dry weight, DW in females and 2.82 ± 1.48% DW in males) and phospholipid (8.23 ± 3.34 μg mg−1 DW in females and 7.91 ± 2.36 μg mg−1 DW in males) were not significantly different between the two sexes. The absolute FA compositions of H. hippocampus trunk muscles revealed higher mean values for FA 16:0, 18:0, 18:1 n-9 and 22:6 n-3 (DHA), in both female (2.82 ± 1.11, 1.81 ± 0.89, 0.90 ± 0.41 and 0.93 ± 0.35 μg mg−1 DW, respectively) and male specimens (1.99 ± 0.95, 1.52 ± 0.78, 0.74 ± 0.44 and 0.80 ± 0.41 μg mg−1 DW, respectively). In terms of FA classes, saturated fatty acids (SFA) showed the highest absolute value of the total pool of FA, for both sexes (4.73 ± 1.94 μg mg−1 DW in females and 3.58 ± 1.76 μg mg−1 DW in males). Males tended to exhibit a more suitable profile for human nutrition, displaying a lower atherogenic index (AI) and thrombogenic index (TI). The relative composition of H. hippocampus trunk muscles followed the patterns of seahorse species valued in TCM, with DHA ranking amongst the PUFA with higher mean relative abundances (12.0% of total FA). While seahorse FA profiles may be of interest in terms of their nutritional value for humans, only specimens originating from sustainable production practices should be traded and the conservation of their populations in the wild should continue to be a global priority.

Phytochemical Composition, Bioactive Compounds, and Antioxidant Properties of Different Parts of Andrographis macrobotrys Nees.

Andrographis macrobotrys Nees is an ethnomedicinal plant belonging to the family Acanthaceae, distributed in the moist deciduous and semi-evergreen forests of the southern Western Ghats of India. The objective of this research was to determine the phytochemical composition and bioactive chemical components using gas chromatography and mass spectrometry (GC-MS) and to check the antioxidant potential of the plant part extracts. A. macrobotrys roots, stems, and leaves were obtained from the species' natural habitat in the Western Ghats, India. The bioactive compounds were extracted using a Soxhlet extractor at 55-60 °C for 8 h in methanol. Identification analysis of A. macrobotrys bioactive compound was performed using GC-MS. Quantitative estimation of phytochemicals was carried out, and the antioxidant capacity of the plant extracts was determined by 2,2'-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) and ferric reducing assays (FRAP). A. macrobotrys has a higher concentration of phenolics in its stem extract than in its root or leaf extracts (124.28 mg and 73.01 mg, respectively), according to spectrophotometric measurements. GC-MS analysis revealed the presence of phytochemicals such as azulene, 2,4-di-tert-butylphenol, benzoic acid, 4-ethoxy-ethyl ester, eicosane, 3-heptadecanol, isopropyl myristate, hexadecanoic acid methyl ester, hexadecanoic acid, 1-butyl-cyclohexanol, 9,12-octadecadienoic acid, alpha-monostearin, and 5-hydroxy-7,8-dimethoxyflavone belonging to various classes of flavonoids, terpenoids, phenolics, fatty acids, and aromatic compounds. Significant bioactive phytochemicals include 2,4-di-tert-butylphenol, 2-methoxy-4-vinylphenol, 5-hydroxy-7,8-dimethoxyflavone, azulene, salvigenin, squalene, and tetrapentacontane. In addition, the antioxidant capability of each of the three extracts was assessed. The stem extract demonstrated impressive DPPH scavenging and ferric reduction activities, with EC50 values of 79 mg/mL and 0.537 ± 0.02 OD at 0.2 mg/mL, respectively. The results demonstrated the importance of A. macrobotrys as a source of medicine and antioxidants.

Ассимиляция экзогенных жирных кислот в тканях радужной форели Parasalmo mykiss (Walbaum, 1792) в аквакультуре

A comparative study of the fatty acids composition in the feed and food lump from the rectum, and in muscles and internal fat of rainbow trout Parasalmo mykiss (Walbaum, 1792) grown on various diets in June and Septem-ber was carried out. Differences in content of dietary fatty acids in diet 1 and diet 2 were found. Monounsaturated fatty acids predominated in diet No. 1. A significantly higher level of saturated and ω3 polyunsaturated fatty acids in diet No. 2 was recorded. Concentration of ω6 polyunsaturated fatty acids in diets was equal. Despite the differences in the fatty acid composition of the diet, a decreased concentration of fatty acids in the intestines for the two groups of fish was similar and did not depend on the month of the study. Polyunsaturated fatty acids were absorbed more effectively in rainbow trout. Monounsaturated fatty acids showed a low level of assimilation. Significant differences in the content of saturated fatty acids in the food lump from the rectum and in feed was not stated. Monounsaturated fatty acids dominated in muscles and visceral fat of rainbow trout compared to other fatty acids. In June concentration of ω3 polyunsaturated fatty acids increased in the muscles of trout species of group No. 2 (143.9 ± 8.9 mg/g lipids), while concentration of monounsaturated fatty acids increased in the internal fat of the fish of group No. 1 (310.8 ± 10.8 mg/g lipids). This fact corresponded to the predominance of these classes of fatty acids in the feed of the fish. Concentration of mono- and polyunsaturated fatty acids in the tissues of the two groups of the fish increased by the end of the exper-iment. Monounsaturated fatty acids were mainly stored in the internal fat of trout, while polyunsaturated fatty acids were deposited in the muscles of the fish.

Protective Effects of Omega-3 Supplementation against Doxorubicin-Induced Deleterious Effects on the Liver and Kidneys of Rats.

Anthracycline doxorubicin (DOX) is still widely used as a chemotherapeutic drug for some solid tumors. Although DOX is highly effective, its side effects are limiting factors, such as cardio, nephro and hepatotoxicity. As such, approaches used to mitigate these adverse effects are highly encouraged. Omega 3 (ω-3), which is a class of long-chain polyunsaturated fatty acids, has been shown to have anti-inflammatory and antioxidant effects in preclinical bioassays. Thus, we evaluated the protective effects of ω-3 supplementation on hepatotoxicity and nephrotoxicity induced by multiple DOX administrations in rodents. Male Wistar rats (10 rats/group) were treated daily with ω-3 (400 mg/kg/day) by gavage for six weeks. Two weeks after the first ω-3 administration, the rats received DOX (3.5 mg/kg, intraperitoneal, 1×/week) for four weeks. DOX treatment reduced body weight gain increased systemic genotoxicity and caused liver-related (increase in serum ALT levels, thickness of the Glisson's capsule, compensatory proliferation and p65 levels) and kidney-related (increase in serum urea and creatinine levels, and incidence of tubular dilatation) deleterious outcomes. In contrast, ω-3 supplementation was safe and abrogated the DOX-related enhancement of systemic genotoxicity, serum urea and creatinine levels. Furthermore, ω-3 intervention reduced by 50% the incidence of kidney histological lesions while reducing by 40-50% the p65 protein level, and the proliferative response in the liver induced by DOX. Our findings indicate that ω-3 intervention attenuated the DOX-induced deleterious effects in the liver and kidney. Therefore, our findings may inspire future mechanistical investigations and clinical interventions with ω-3 on the reported outcomes.

The influence of temperature on performance, biological indices, composition, and nutrient retention of juvenile Chinook salmon (Oncorhynchus tshawytscha) reared in freshwater

This study investigated the effects of different temperatures on the performance, composition, and nutrient retention of Chinook salmon reared in freshwater. Individuals (187.6 ± 27.1 g) were distributed into twelve tanks of 8000 L each (155 to 157 fish per tank) at a temperature of 14 °C. The tanks were transitioned from 14 °C (hatchery temperature) to 8, 12, 16, and 20 °C over seven days. Three fish assessments were performed, the first (initial) when the fish were distributed in the tanks, a second (interim) between days 9 and 16 at the start of the experiment, and a third (final) after 41 to 49 days at the target temperature. At the end of the trial, performance parameters, proximate composition, amino acid, and fatty acid composition, and nutrient retention were evaluated. Better growth performance was observed in fish at 16 °C and 20 °C compared to the lower temperatures. Fish at higher temperatures had higher levels of saturated fatty acids (SFA), while at lower temperatures fish had higher levels of n-3 and n-6 polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). A polynomial relationship between nutrient retention and temperature showed that fish from all treatments retained more lipids than proteins, with higher retention of MUFA compared to the other fatty acid classes. Additionally, DHA retention was approximately three times higher than EPA retention. The results showed that 16 to 20 °C was the optimum temperature range for Chinook salmon, and the performance differences were mainly modulated by lipid retention/catabolism.

In the Beginning Was the Bud: Phytochemicals from Olive (Olea europaea L.) Vegetative Buds and Their Biological Properties.

Even though Olea europaea L. is one of the most important and well-studied crops in the world, embryonic parts of the plants remain largely understudied. In this study, comprehensive phytochemical profiling of olive vegetative buds of two Croatian cultivars, Lastovka and Oblica, was performed with an analysis of essential oils and methanol extracts as well as biological activities (antioxidant, antimicrobial, and cytotoxic activities). A total of 113 different volatiles were identified in essential oils with hydrocarbons accounting for up to 60.30% and (Z)-3-heptadecene being the most abundant compound. Oleacein, oleuropein, and 3-hydroxytyrosol had the highest concentrations of all phenolics in the bud extracts. Other major compounds belong to the chemical classes of sugars, fatty acids, and triterpenoid acids. Antioxidant, antimicrobial, and cytotoxic activities were determined for both cultivars. Apart from antioxidant activity, essential oils had a weak overall biological effect. The extract from cultivar Lastovka showed much better antioxidant activity than both isolates with both methods (with an oxygen radical absorbance capacity value of 1835.42 μM TE/g and DPPH IC50 of 0.274 mg/mL), as well as antimicrobial activity with the best results against Listeria monocytogenes. The human breast adenocarcinoma MDA-MB-231 cell line showed the best response for cultivar Lastovka bud extract (IC50 = 150 μg/mL) among three human cancer cell lines tested. These results demonstrate great chemical and biological potential that is hidden in olive buds and the need to increase research in the area of embryonic parts of plants.

The Modulatory Effects of Fatty Acids on Cancer Progression

Cancer is the second leading cause of death worldwide and the global cancer burden rises rapidly. The risk factors for cancer development can often be attributed to lifestyle factors, of which an unhealthy diet is a major contributor. Dietary fat is an important macronutrient and therefore a crucial part of a well-balanced and healthy diet, but it is still unclear which specific fatty acids contribute to a healthy and well-balanced diet in the context of cancer risk and prognosis. In this review, we describe epidemiological evidence on the associations between the intake of different classes of fatty acids and the risk of developing cancer, and we provide preclinical evidence on how specific fatty acids can act on tumor cells, thereby modulating tumor progression and metastasis. Moreover, the pro- and anti-inflammatory effects of each of the different groups of fatty acids will be discussed specifically in the context of inflammation-induced cancer progression and we will highlight challenges as well as opportunities for successful application of fatty acid tailored nutritional interventions in the clinic.

Biotin and Leucine Alone or in Combination Promoted the Synthesis of Odd- and Branched-Chain Fatty Acids in the Rumen In Vitro

The odd- and branched-chain fatty acids (OBCFA) accumulated in ruminant products are a class of beneficial fatty acids for human health. Since biotin and leucine are involved in OBCFA synthesis, this study aimed to evaluate their effect on OBCFA synthesis in vitro. There were four treatments: the control group that only provided the basal diet, or the basal diet supplemented with biotin (4 mg/kg dry matter, DM), leucine (4 g/kg DM), or a combination of biotin (4 mg/kg DM) and leucine (4 g/kg DM). The results showed that biotin promoted the degradation of DM (p < 0.10), while leucine significantly increased the concentration of branched-chain volatile fatty acids and valerate (p < 0.05). The concentrations of total odd-chain fatty acids, total iso, total anteiso, total branched-chain fatty acids, total OBCFA, and total fatty acids were significantly increased by the supplementation of biotin or leucine (p < 0.05). Biotin and leucine significantly stimulated the activities of acetyl-CoA carboxylase, fatty acid synthase, and malonyl-CoA, with a significant interaction effect (p < 0.05). In conclusion, the results of this study suggested that biotin and leucine can be used as effective nutrition strategies to promote OBCFA synthesis.

Effects of the Expressions and Variants of the CAST Gene on the Fatty Acid Composition of the Longissimus Thoracis Muscle of Grazing Sonid Sheep.

Fatty acid (FA) composition has an important impact on the nutrition and flavor of meat, and on consumer health, and is receiving more attention in the sheep industry. This study aimed to evaluate the relationship between the expression levels of the CAST gene and the FA composition in the longissimus thoracis (LL) muscle, to identify novel variants of CAST, and to perform association analysis with the FA composition in grazing Sonid lambs. The correlation results showed that high expression levels of CAST are correlated with better FA compositions and classes in LL. For association studies, the results showed that c.1210C>T and c.1437G>A in LD-M, and c.2097C>T mutations are associated with some compositions and classes of FA in the LL of grazing Sonid sheep. Two missense c.646G>C (G216R) and c.1210C>T (R404C) mutations were predicted to influence the Calpain_inhib domains of CAST. Thus, the correlation results and associated mutations are expected to be genetic selection markers for the FA composition and meat quality of grazing Sonid lamb muscle and provide new insights into sheep meat quality traits influenced by the ovine CAST gene.

Metabolite profiling from different parts of tender fruit endosperm of Borassus flabellifer L. (ice apple).

Borassus flabellifer L., commonly known as Asian palmyra, is native to South and Southeast Asia. The endosperms of B. flabellifer (known as nungu in Dravidian culture) are widely consumed during the summer season. It is rich in various nutrients and helps in reducing weight, treating skin and digestive issues, lowering body temperature, and managing migraines and diabetes. This study focuses on identifying the small molecules and proteins from the two varieties of B. flabellifer tender fruit endosperms collected from districts around Chennai, Tamil Nadu, India. The collected free nuclear endosperm was subjected to direct extraction and the mesocarp and cellular endosperms were lyophilized and homogenized. Metabolites were extracted by hexane, methanol, and chloroform and investigated using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). The compounds identified were from the classes of carboxylic acids, flavonoids, amino acids, alkaloids, fatty acids, oligopeptides, vitamins, and glycosides. High-performance liquid chromatography (HPLC) technique was employed to estimate the quantity of amino acids, wherein the total amino acid in the green variety was found to be higher than in the black variety. Proteins were identified after simulating with a gastrointestinal enzyme using liquid chromatography tandem mass spectrometry (LC-MS/MS)-based peptide mass fingerprinting. The different mineral oxides present in the tender fruit endosperm were identified using X-ray diffraction studies, which confirmed the presence of mineral oxides, such as Br1.25ClO2.75Pb3.88, calcium zirconium tantalum oxide, and barium fluoroniobate. This study validates the presence of bioactive metabolites in green and black varieties of B. flabellifer tender fruit endosperm with a range of activities, such as anti-inflammatory, antibacterial, anticancer, and anti-diabetic properties.

Characterization of polar and non-polar lipids of Hermetia illucens and Tenebrio molitor meals as animal feed ingredients

Although increasingly used in animal feeding, the black soldier fly (Hermetia illucens - HI) and mealworm (Tenebrio molitor - TM) larvae and pupae require the characterization and modulation of their fat profile for use in the feed industry. In this study, we provide a comprehensive fatty acid profile of the total lipid triglycerides and phospholipids, and sterol composition. For a more detailed characterization of the nutritional properties, we defined the profile of esterified fatty acids (FAs) in the sn-2 position of the triglycerides, which represents the most adsorbed fraction by animals during digestion. Twenty-four batches (12 batches per species divided into 6 batches of larvae and 6 batches of pupae) of 70 subjects were used for the analysis. For each of the developmental stages, individuals in the intermediate stage were considered (2 months and 8 days for TM larvae and pupae respectively; 9 days and 7 days for HI larvae and pupae respectively). Some fatty acids (decanoic, lauric, or myristic acid) were more abundant in HI than in TM. These FAs were produced de novo, indicating that HI produce them from carbohydrates as a source of acetyl-CoA. Hermetia illucens showed a higher level of conjugated linoleic acid (CLA) isomers, a class of fatty acids with positive health effects. In contrast, TM showed a similar fatty acid profile to the plant lipid source (such as soy and sunflower) due to the high level of linoleic acid. Analysis of the triglyceride fraction showed a different affinity for the three glyceride positions. In particular, lauric acid, polyunsaturated fatty acids n-3 and CLA isomers esterified preferentially in sn-2, and therefore were the most adsorbed by the animal during digestion. As for the phospholipids, HI showed a higher level, above all in terms of the phosphatidylethanolamine fraction. Interestingly there was no sphingomyelin in the pupae of both species. The high level of phospholipids is a useful feature for the emulsion of fats in animal feed diets. Lastly, we observed a considerable amount of phytosterol in the sterol profile of both species, which makes these insects a valid alternative to other food sources of plant origin for animal nutrition. We believe that our findings provide new nutritional information for the use of TM and HI in the animal diet.

TMET-22. ENHANCED LIPID METABOLISM IN BRAIN TUMORS: AN EXPLOITABLE METABOLIC VULNERABILITY THROUGH DIET-INDUCED KETOSIS

Abstract Enhanced lipid metabolism contributes towards carcinogenesis at multiple levels, serving as a "gain of function" in several cancers, including glioblastoma. Seemingly paradoxical to these findings, pre-clinical investigations have demonstrated anti-tumor activity in mice fed a high fat/low carbohydrate ketogenic diet (KD), both alone and in combination with conventional therapy. Therefore, we sought to define mechanistic underpinnings contributing towards this apparent disconnect. Consistent with previous reports, mice fed a KD demonstrated independent anti-tumor activity and potent synergy with RT when tested in an aggressive glioblastoma orthotopic model. To provide a window into metabolic consequences of a KD in glioblastoma, we performed global metabolomic profiling on tumors and serum from mice fed a standard diet and KD. Although ketosis was confirmed, no change in glucose was observed in serum of KD mice, suggesting presence/absence of carbohydrates might not be contributing to the observed anti-tumor activity. Interestingly, profound intra-tumoral metabolic changes were observed in intracranial tumors from mice fed a KD, with an accumulation of unsaturated fatty acids emerging as a central metabolic node. Intriguingly, recapitulating these findings in culture conditions in vitro, polyunsaturated fatty acid linoleic acid demonstrated anti-proliferative activity, decreased clonogenic capacity, and synergy with RT in GBM cells, recapitulating in vivo findings. This was not observed when cultured with the monounsaturated fatty acid oleic acid. Through a series of investigations, we went on to identify lipid storage homeostasis and lipotoxicity associated with free fatty acid accumulation played a contributory role in the differential activity of these different classes of fatty acids. Importantly, PUFA-rich modified diet showed potent antitumor activity in combination with RT in our preliminary investigation. These studies collectively reaffirm and provide mechanistic underpinnings of the anti-tumor activity of a KD, suggesting that enhanced lipid metabolism in brain tumors may serve as an exploitable metabolic vulnerability through diet modification.

Circulating fatty acids from high-throughput metabolomics platforms as potential biomarkers of dietary fatty acids

Some fatty acids, i.e. n-3 and n-6 polyunsaturated fatty acids (PUFA), from metabolomics platforms based on nuclear magnetic resonance imaging (NMR) or liquid chromatography mass-spectrometry (LC-MS) are suggested to reflect dietary exposure. NMR and LC-MS are both relatively fast and cheap, however few studies have investigated their validity. Linoleic acid (LA) and docosahexaenoic acid (DHA), measured using gas chromatography (GC), are established biomarkers of dietary n-6 and n-3 PUFA intake, respectively. To examine if circulating fatty acids derived from two commonly applied metabolomics platforms (using NMR and LC-MS) provide similar information compared to GC in two pooled population-based cohorts, one patient cohort, and in a randomized controlled trial (RCT). Spearman rank correlations were conducted between LA and DHA in cholesteryl esters (CE) from GC and whole serum/plasma LA and DHA from the metabolomics platforms in a pooled population-based cohort of men and women (n˜1100) (primary analysis). Secondary correlation analyses included fatty acid classes such as n-3 PUFA, n-6 PUFA, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and total PUFA. Additionally, correlations were investigated for LA, DHA and the five fatty acid classes in phospholipids (PL), triacylglycerols (TAG) and non-esterified fatty acids (NEFA) in a RCT of n=60 as well as in a population with biopsy-verified non-alcoholic fatty liver disease (NAFLD) (n=59). Misclassification was examined using cross-tabulation and visualized using alluvial plots. Moderate to strong correlations (r=0.51-0.81) were observed for LA and DHA in multiple lipid fractions in all cohorts using the NMR platform. For the pooled cohort, LA (r=0.67, P<0.0001) and DHA (r=0.68, P<0.0001) assessed in CE were strongly correlated with LA and DHA derived using NMR. Nearly half (49%) were correctly classified into their respective quartiles. Using LC-MS, only DHA (r=0.44, P<0.0001) demonstrated moderate correlations with DHA from GC. Unless fatty acid data from GC analysis is available or feasible, NMR-based technology might be a better option than a LC-MS-based platform, at least for certain PUFA. This should be taken into account in future studies aiming to use circulating fatty acids as dietary biomarkers for the investigation of diet-disease relationships.

Multifaced Assessment of Antioxidant Power, Phytochemical Metabolomics, In-Vitro Biological Potential and In-Silico Studies of Neurada procumbens L.: An Important Medicinal Plant.

This work was undertaken to explore the phytochemical composition, antioxidant, and enzyme-inhibiting properties of Neurada procumbens L. extracts/fractions of varying polarity (methanol extract and its fractions including n-hexane, chloroform, n-butanol, and aqueous fractions). A preliminary phytochemical study of all extracts/fractions, HPLC-PDA polyphenolic quantification, and GC-MS analysis of the n-hexane fraction were used to identify the phytochemical makeup. Antioxidant (DPPH), enzyme inhibition (against xanthine oxidase, carbonic anhydrase, and urease enzymes), and antibacterial activities against seven bacterial strains were performed for biological investigation. The GC-MS analysis revealed the tentative identification of 22 distinct phytochemicals in the n-hexane fraction, the majority of which belonged to the phenol, flavonoid, sesquiterpenoid, terpene, fatty acid, sterol, and triterpenoid classes of secondary metabolites. HPLC-PDA analysis quantified syringic acid, 3-OH benzoic acid, t-ferullic acid, naringin, and epicatechin in a significant amount. All of the studied extracts/fractions displayed significant antioxidant capability, with methanol extract exhibiting the highest radical-scavenging activity, as measured by an inhibitory percentage of 81.4 ± 0.7 and an IC50 value of 1.3 ± 0.3. For enzyme inhibition experiments, the n-hexane fraction was shown to be highly potent against xanthine oxidase and urease enzymes, with respective IC50 values of 2.3 ± 0.5 and 1.1 ± 0.4 mg/mL. Similarly, the methanol extract demonstrated the strongest activity against the carbonic anhydrase enzyme, with an IC50 value of 2.2 ± 0.4 mg/mL. Moreover, all the studied extracts/fractions presented moderate antibacterial potential against seven bacterial strains. Molecular docking of the five molecules β-amyrin, campesterol, ergosta-4,6,22-trien-3β-ol, stigmasterol, and caryophyllene revealed the interaction of these ligands with the investigated enzyme (xanthine oxidase). The results of the present study suggested that the N. procumbens plant may be evaluated as a possible source of bioactive compounds with multifunctional therapeutic applications.

Serum ω-3 Fatty Acids and Cognitive Domains in Community-Dwelling Older Adults from the NuAge Study: Exploring the Associations with Other Fatty Acids and Sex

BackgroundOmega-3 (n–3) PUFAs are suggested to play a role in the prevention of cognitive decline. The evidence may be inconsistent due to methodologic issues, including interrelations with other long-chain (14 or more carbons) fatty acids (LCFAs) and use of sex as a confounding factor rather than an effect modifier ObjectivesThis study evaluated the association between serum n–3 PUFAs and performance across 4 cognitive domains, overall and by sex, while controlling for other LCFAs MethodsIn total, 386 healthy older adults (aged 77.4 ± 3.8 y; 53% females) from the Quebec Longitudinal Study on Nutrition and Successful Aging underwent a cognitive evaluation and blood sampling. Verbal and nonverbal episodic memory, executive functioning, and processing speed were evaluated. Serum LCFA concentrations were measured by gas chromatography. LCFAs were grouped according to standard fatty acid classes and factor analysis using principal component analysis (FA-PCA). Multivariate linear regression models were performed, including unadjusted and adjusted models for other LCFAs ResultsHigher n–3 PUFA concentrations were associated with better nonverbal memory and processing speed in fully adjusted models not including other LCFAs (βs of 0.21 and 0.19, respectively). The magnitude of these associations varied when other LCFAs were entered in the model (βs of 0.27 and 0.32, respectively) or when FA-PCA factors were considered (βs of 0.27 and 0.21, respectively). Associations with verbal episodic memory were limited to higher concentrations of EPA, whereas there was no association between n–3 PUFAs and executive functioning. Higher n–3 PUFAs were associated with better verbal and nonverbal episodic memory in females and with better executive functioning and processing speed in males ConclusionsThese results suggest that other LCFAs should be considered when evaluating the association between n–3 PUFAs and cognitive performance in healthy older adults. Sex differences across cognitive domains warrant further investigation. J Nutr 2022;152:2117–2124.

Quality of dietary fat and risk of Alzheimer’s disease and dementia in adults aged ≥50 years: a systematic review

ObjectiveTo identify, critically appraise, and synthesize evidence on the effect of quality of dietary fat intake and different classes of fatty acids on the risk of Alzheimer’s disease (AD) and dementia in adults aged ≥50 years.MethodsWe searched MEDLINE, EMBASE, Cochrane Central of Controlled Trials, and Scopus for clinical trials and prospective cohort studies published until May 2021. Two reviewers independently screened retrieved literature, extracted relevant data, and performed risk of bias assessment. Classes of fatty acids included were saturated fatty acids (SFAs), trans fatty acids (TFAs), monounsaturated fatty acids (MUFAs), poly-unsaturated fatty acids (PUFAs), and their subtypes and sources. Given between-study heterogeneity, we did not perform meta-analyses but narratively described findings from the studies.ResultsFrom 4,491 identified records, five articles (based on four prospective cohort studies) met the inclusion criteria. Three studies had an overall serious risk of bias, while one study had a moderate risk. Overall, we found no robust association between intake of any fatty acids type and the development of AD and dementia. For example, for SFA and TFA, there was contradictory associations reported on AD: one study found that each unit increase in energy-adjusted intake of SFA (risk ratio [RR] 0.83, 95%CI 0.70–0.98) and TFA (RR 0.80, 95%CI 0.65–0.97) was associated with a decreased risk of AD, but not dementia. For PUFA, one study found that higher quintile intake of marine-based n-3 PUFA was associated with a decreased risk of AD. The intake of other fatty acids was not associated with the outcomes. The certainty of the overall evidence was inconclusive.ConclusionWe found no clear association between the intake of various classes of fatty acids and the risk of AD and dementia in adults. More well-designed prospective studies are required to clarify these findings.

Influence of very-long-chain polyunsaturated fatty acids on membrane structure and dynamics

The unique attributes of very-long-chain polyunsaturated fatty acids (VLC-PUFAs), their long carbon chains (n > 24) and high degree of unsaturation, impart unique chemical and physical properties to this class of fatty acids. The changes imparted by VLC-PUFA 32:6 n-3 on lipid packing and the compression moduli of model membranes were evaluated from π-A isotherms of VLC-PUFA in 1,2-distearoyl-sn-3-glycero-phosphocholine (DSPC) lipid monolayers. To compare the attractive or repulsive forces between VLC-PUFA and DSPC lipid monolayers, the measured mean molecular areas (MMAs) were compared with the calculated MMAs of an ideal mixture of VLC-PUFA and DSPC. The presence of 0.1, 1, and 10 mol % VLC-PUFA shifted the π-A isotherm to higher MMAs of the lipids comprising the membrane and the observed positive deviations from ideal behavior of the mixed VLC-PUFA:DSPC monolayers correspond to repulsive forces between VLC-PUFAs and DSPC. The MMA of the VLC-PUFA component was estimated using the measured MMAs of DSPC of 47.1 ± 0.7 Å2/molecule, to be 15,000, 1100, and 91 Å2/molecule at 0.1, 1, and 10 mol % VLC-PUFA:DSPC mixtures, respectively. The large MMAs of VLC-PUFA suggest that the docosahexaenoic acid tail reinserts into the membrane and adopts a nonlinear structure in the membrane, which is most pronounced at 0.1 mol % VLC-PUFA. The presence of 0.1 mol % VLC-PUFA:DSPC also significantly increased the compression modulus of the membrane by 28 mN/m compared with a pure DSPC membrane. The influence of VLC-PUFA on lipid “flip-flop” was investigated by sum-frequency vibrational spectroscopy. The incorporation of 0.1 mol % VLC-PUFA increased the DSPC flip-flop rate fourfold. The fact that VLC-PUFA promotes lipid translocation is noteworthy as retinal membranes require a high influx of retinoids which may be facilitated by lipid flip-flop.

Abstract 17: Enhanced lipid metabolism in brain tumors: An exploitable metabolic vulnerability through diet-induced ketosis

Abstract Altered metabolism displayed by cancer cells helps circumvent a plethora of microenvironmental stressors. We and others have identified enhanced lipid metabolism as an important metabolic pathway in tumors of different etiologies. This “gain of function” contributes to malignant transformation in various malignancies, including brain tumors. Paradoxical to these findings, a high-fat/low carbohydrate ketogenic diet (KD) has demonstrated anti-tumor activity, both alone and in combination with radiation therapy (RT). Therefore, using our novel patient-derived GBM stem cell models, we sought to define mechanistic underpinnings contributing to this disconnect from a metabolic perspective. As an initial investigation, we fed ad libitum standard diet (SD) or KD alone or in combination with hypofractionated RT (hfRT; 6 Gy x 3) to mice injected orthotopically with aggressive GBM tumor cells. Consistent with previous reports, mice fed a KD demonstrated independent anti-tumor activity and potent synergy with RT compared to mice fed a SD. To provide a window into the metabolic consequences of KD in GBM, we performed global metabolomic profiling on tumors and serum from mice fed a SD and KD. Although ketosis was confirmed, no change in glucose was observed in serum of KD mice, suggesting carbohydrates might not be contributing to the observed anti-tumor activity. Interestingly, profound intra-tumoral metabolic changes were observed in tumors from mice fed a KD, with an accumulation of unsaturated fatty acids emerging as a central metabolic node differentiating KD and SD, which was consistent with serum studies. To begin to understand the biologic consequence of these findings, we recapitulated these findings in culture conditions in vitro. Intriguingly, culturing GBM cells with the polyunsaturated fatty acid (PUFA) linoleic acid demonstrated anti-proliferative activity, decreased clonogenic capacity, and synergy with RT in, recapitulating in vivo findings. This was not observed when cultured with the monounsaturated fatty acid oleic acid. Through a series of investigations, we went on to identify lipid storage homeostasis played a contributory role in the differential activity of these different classes of fatty acids. Specifically, we discovered that long-term storage within lipid droplets was less efficient for PUFA, leading to an increase free fatty acid accumulation in cells and lipotoxicity. The anti-tumor activity of PUFAs were rescued following inhibition of lipolysis. These studies collectively reaffirm and provide mechanistic underpinnings of the antitumor activity of KD, suggesting enhanced FA metabolism in brain tumors may serve as an exploitable metabolic vulnerability through diet modification. In addition, it provides a framework to potentially modify this diet to both enhance its antitumor activity and improve tolerability to allow for clinical implementation. Citation Format: Shiva Kant, Pravin Kesarwani, Yi Zhao, Prakash Chinnaiyan. Enhanced lipid metabolism in brain tumors: An exploitable metabolic vulnerability through diet-induced ketosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 17.