Long-chain Monounsaturated Fatty Acid Research Articles

Nervonic acid alleviates stroke and its associated poststroke depression behaviors

Nervonic acid (NA) is an important long-chain monounsaturated fatty acid found in mammalian nervous tissue. It has recently garnered research attention due to its therapeutic potential in treating psychiatric and neurodegenerative disorders. In this study, we investigated the efficacy of NA in treating ischemia/reperfusion and poststroke events in a rat model. Specifically, there was significant reduction in the infarct area, cell death, and neuronal swelling after NA treatment, and the improvement in cerebral blood flow was also observed on day five after middle cerebral artery occlusion. Moreover, NA treatment led to the upregulation of brain-derived neurotrophic factors and myelin basic protein genes. NA displayed improved effects on depressive-like behavior of rats by three validated assays—the sucrose preference test, open-field test, and forced swim test. Regarding the mechanism of action, direct supplementation of NA in the brain was observed. We also observed the indirect effects of NA on the gut microbiota. Notably, the NA group gradually restored the bacterial diversity and the EGb group exhibited no impact based on observed-out analysis. We found an increase in the abundance of Blautia and Sutterella, which participated in phenylalanine metabolism. The metabolomics of plasma and brain samples revealed a decrease in the levels of phenylalanine-based amino acids, which alleviated the inhibitory effects on glutamine metabolism and promoted the recovery and signaling transmission of neurons after stroke. Altogether, our findings suggest that NA can be a viable treatment option for alleviating stroke and its associated poststroke depressive-like behaviors.

Effects of diets containing fish oils or fish oil concentrates with high cetoleic acid content on the circulating cholesterol concentration in rodents. A systematic review and meta-analysis.

Hypercholesterolaemia is a major risk factor for CVD. Fish intake is associated with lower risk of CVD, whereas supplementation with n-3 long-chain PUFA (LC-PUFA) has little effect on the cholesterol concentration. We therefore investigated if cetoleic acid (CA), a long-chain MUFA (LC-MUFA) found especially in pelagic fish species, could lower the circulating total cholesterol (TC) concentration in rodents. A systematic literature search was performed using the databases PubMed, Web of Science and Embase, structured around the population (rodents), intervention (CA-rich fish oils or concentrates), comparator (diets not containing CA) and the primary outcome (circulating TC). Articles were assessed for risk of bias using the SYRCLE's tool. A meta-analysis was conducted in Review Manager v. 5.4.1 (the Cochrane Collaboration) to determine the effectiveness of consuming diets containing CA-rich fish oils or concentrates on the circulating TC concentration. Twelve articles were included in the systematic review and meta-analysis, with data from 288 rodents. Consumption of CA-rich fish oils and concentrates resulted in a significantly lower circulating TC concentration relative to comparator groups (mean difference -0·65 mmol/l, 95 % CI (-0·93, -0·37), P < 0·00001), with high statistical heterogeneity (I2 = 87 %). The risk of bias is unclear since few of the entries in the SYRCLE's tool were addressed. To conclude, intake of CA-rich fish oils and concentrates prevents high cholesterol concentration in rodents and should be further investigated as functional dietary ingredients or supplements to reduce the risk for developing CVD in humans.

Higher Availability of Long-Chain Monounsaturated Fatty Acids in Preterm than in Full-Term Human Milk.

While the role of n-3 and n-6 long-chain polyunsaturated fatty acids (LCPUFAs) in the maturation of the infantile nervous system is extensively studied and relatively well-characterized, data on the potential developmental importance of the n-9 long-chain monounsaturated fatty acid (LCMUFA), nervonic acid (NA, C24:1n-9) are scarce and ambiguous. Therefore, the aim of the present study was to reanalyze our available data on the contribution of NA and its LCMUFA precursors, gondoic acid (C20:1n-9) and erucic acid (EA, C22:1n-9) to the fatty acid composition of human milk (HM) during the first month of lactation in mothers of both preterm (PT) and full-term (FT) infants. HM samples were obtained daily during the first week of lactation, and then on the 14th, 21st, and 28th days. Values of the LCMUFAs, C20:1n-9, EA, and NA were significantly higher in colostrum than in transient and mature HM. Consequently, there were highly significant inverse associations between LCMUFA values and the duration of lactation. Moreover, C20:1n-9, EA, and NA values were monotonously, considerably, and at many timepoints significantly higher in PT than in FT HM samples. By the 28th day of lactation, summarized LCMUFA values in PT HM samples declined to the level measured in FT HM samples on the first day of lactation; however, EA and NA values were still significantly higher in PT than in FT HM on the 28th day. Significantly higher availability of LCMUFAs in PT than in FT HM underpins the potential biological role of this hitherto somewhat neglected group of fatty acids.

Improved colonic inflammation by nervonic acid via inhibition of NF-κB signaling pathway of DSS-induced colitis mice

BackgroundNervonic acid (C24:1∆15, 24:1 ω-9, cis-tetracos-15-enoic acid; NA), a long-chain monounsaturated fatty acid, plays an essential role in prevention of metabolic diseases, and immune regulation, and has anti-inflammatory properties. As a chronic, immune-mediated inflammatory disease, ulcerative colitis (UC) can affect the large intestine. The influences of NA on UC are largely unknown. PurposeThe present study aimed to decipher the anti-UC effect of NA in the mouse colitis model. Specifically, we wanted to explore whether NA can regulate the levels of inflammatory factors in RAW264.7 cells and mouse colitis model. MethodsTo address the above issues, the RAW264.7 cell inflammation model was established by lipopolysaccharide (LPS), then the inflammatory factors tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-1β (IL-1β), and Interleukin-10 (IL-10) were detected by Enzyme-linked immunosorbent assay (ELISA). The therapeutic effects of NA for UC were evaluated using C57BL/6 mice gavaged dextran sodium sulfate (DSS). Hematoxylin and eosin (H&E) staining, Myeloperoxidase (MPO) kit assay, ELISA, immunofluorescence assay, and LC-MS/MS were used to assess histological changes, MPO levels, inflammatory factors release, expression and distribution of intestinal tight junction (TJ) protein ZO-1, and metabolic pathways, respectively. The levels of proteins involved in the nuclear factor kappa-B (NF-κB) pathway in the UC were investigated by western blotting and RT-qPCR. ResultsIn vitro experiments verified that NA could reduce inflammatory response and inhibit the activation of key signal pathways associated with inflammation in LPS-induced RAW264.7 cells. Further, results from the mouse colitis model suggested that NA could restore intestinal barrier function and suppress NF-κB signal pathways to ameliorate DSS-induced colitis. In addition, untargeted metabolomics analysis of NA protection against UC found that NA protected mice from colitis by regulating citrate cycle, amino acid metabolism, pyrimidine and purine metabolism. ConclusionThese results suggested that NA could ameliorate the secretion of inflammatory factors, suppress the NF-κB signaling pathway, and protect the integrity of colon tissue, thereby having a novel role in prevention or treatment therapy for UC. This work for the first time indicated that NA might be a potential functional food ingredient for preventing and treating inflammatory bowel disease (IBD).

Erythrocyte, Whole Blood, Plasma, and Blubber Fatty Acid Profiles in Oceanaria-Based versus Wild Alaskan Belugas (Delphinapterus leucas)

This investigation compared the fatty acid (FA) levels found in erythrocyte (RBC) membranes, plasma, whole blood (WB), and blubber from wild Alaskan (Bristol Bay) belugas (Delphinapterus leucas) (BBB, n = 9) with oceanaria-based belugas (OBB, n = 14) fed a controlled diet consisting of primarily herring (Clupea harengus) and capelin (Mallotus villosus). FA patterns in RBCs, WB, and plasma varied considerably between BBB and OBB animals. Focusing on RBC FA levels of known dietary origin, the OBBs had markedly higher levels of 20:1n9,11 and 22:1n9,11. RBC levels of these fatty acids were 1% and 0.2% in the BBBs, but 8.2% and 4.5%, respectively, in the OBBs (p &lt; 0.05 both). These long-chain mono-unsaturated FAs (LC-MUFAs) are rich in herring and capelin but not in the prey species (i.e., salmonids, smelt, cod, and shrimp) generally available to BBBs. As for the marine omega-3 poly-unsaturated fatty acids [PUFAs; 20:5n3 (eicosapentaenoic acid) and 22:6n3 (docosahexaenoic acid)], the former was higher in the OBBs vs. BBBs (16% vs. 11%, p &lt; 0.05), but the latter was low and similar in both (3.8% vs. 4%). Similar patterns were seen in the other sample types, except that DHA% was higher in BBB than OBB animals in both plasma (12.6% vs. 8.7%) and in blubber (12% vs. 4.9%) (p &lt; 0.05). A physiologically important omega-6 PUFA, 20:4n6 (arachidonic acid) was approximately 2× higher in BBB than OBB within RBC (22% vs. 12%), WB (16% vs. 7%), plasma (11.5% vs. 4.6%) and blubber (4.6% vs. 2.4%), respectively. While blubber FAs have been evaluated historically and relatively easy to procure with biopsy darts in the field, this study proposes that blood-based FAs collected during health assessments or subsistence hunts, especially RBC or WB FAs, may be more convenient to handle using dried blood spot cards (DBS) with limited cold storage and simplifies shipping requirements, and may more accurately reflect tissue FA status.

Individual non-esterified fatty acids and incident atrial fibrillation late in life

ObjectiveObesity and dysmetabolism are major risk factors for atrial fibrillation (AF). Expansion of fat depots is associated with increased circulating total non-esterified fatty acids (NEFAs), elevated levels of which are...

Semi-refined Crambe abyssinica (Hochst. EX R.E.Fr.) oil as a biobased hydraulic fluid for agricultural applications

Vegetable oils are well known for their potential applications in green chemistry, including use as hydraulic fluids. Among oilseed crops, Crambe abyssinica Hochst. EX R.E.Fr . gained attention for its low-input requirements during cultivation and for the properties of its oil, characterised by a high erucic acid content. This long-chain mono-unsaturated fatty acid provides appreciable features that make the oil suitable for interesting green chemistry sectors, as biolubricants and cosmetics. In the present work, Crambe oil was tested as a hydraulic fluid for sustainable agricultural applications. Crambe oil was partially refined through phospholipid removal and added with a food-grade antioxidant (tert-butylhydroquinone) at two different concentrations. The fluid efficiency tests were carried out using an experimental test rig, able to simulate a real hydraulic device, performing heavy work cycles at 40-MPa pressure and at 100 °C temperature, with the aim of strongly accelerating the ageing of the tested fluid. At a lower antioxidant concentration, 0.25 g kg−1, the oil underwent a very quick degradation process. However, increasing the additive dose to 2.0 g kg−1, the fluid maintained stable performances. Indeed, all parameters, referred to oil chemical-physical stability and technical performance, were constant along the entire work cycle, up to 290 h. Finally, the present work showed how Crambe seed cultivation, oil extraction and exploitation in the hydraulic circuit of farm machinery could be developed applying green chemistry approaches aiming at small-scale biorefineries linked to the local supply.

Simultaneous Treatment of Long-chain Monounsaturated Fatty Acid and n-3 Polyunsaturated Fatty Acid Decreases Lipid and Cholesterol Levels in HepG2 Cell.

The n-3 type polyunsaturated fatty acids (n-3PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), from fish oil exhibit health benefits such as triacylglycerol- and cholesterol-lowering effects. Some pelagic fishes contain long-chain monounsaturated fatty acids (LC-MUFAs) such as eicosenoic acid (C20:1), which exert health-promoting effects. However, no study has evaluated beneficial effects of n-3PUFA and LC-MUFA combination. Here, we investigated effects of simultaneous treatment with n-3PUFA (EPA and DHA) and LC-MUFA (cis-5-C20:1 and cis-7-C20:1) and found that n-3PUFA and LC-MUFA combination significantly decreased lipid accumulation and reduced total cholesterol in HepG2 cells. Cholesterol level was significantly lower in DHA + cis-7-C20:1 group than in DHA + EPA group. These results suggest the importance of LC-MUFA as a functional molecule in fish oil.

Reducing Pup Litter Size Alters Early Postnatal Calcium Homeostasis and Programs Adverse Adult Cardiovascular and Bone Health in Male Rats.

The in utero and early postnatal environments play essential roles in offspring growth and development. Standardizing or reducing pup litter size can independently compromise long-term health likely due to altered milk quality, thus limiting translational potential. This study investigated the effect reducing litter size has on milk quality and offspring outcomes. On gestation day 18, dams underwent sham or bilateral uterine vessel ligation surgery to generate dams with normal (Control) and altered (Restricted) milk quality/composition. At birth, pups were cross-fostered onto separate dams with either an unadjusted or reduced litter size. Plasma parathyroid hormone-related protein was increased in Reduced litter pups, whereas ionic calcium and total body calcium were decreased. These data suggest Reduced litter pups have dysregulated calcium homeostasis in early postnatal life, which may impair bone mineralization decreasing adult bone bending strength. Dams suckling Reduced litter pups had increased milk long-chain monounsaturated fatty acid and omega-3 docosahexaenoic acid. Reduced litter pups suckled by Normal milk quality/composition dams had increased milk omega-6 linoleic and arachidonic acids. Reduced litter male adult offspring had elevated blood pressure. This study highlights care must be taken when interpreting data from research that alters litter size as it may mask subtle cardiometabolic health effects.

Dietary supplementation with long-chain monounsaturated fatty acid isomers decreases atherosclerosis and alters lipoprotein proteomes in LDLr−/− mice

Background and aimsConcentrated fish oils, containing a mixture of long-chain monounsaturated fatty acids (LCMUFA) with aliphatic chains longer than 18 C atoms (i.e., C20:1 and C22:1), have been shown to attenuate atherosclerosis development in mouse models. It is not clear, however, how individual LCMUFA isomers may act on atherosclerosis. MethodsIn the present study, we used saury fish oil-derived concentrates enriched in either C20:1 or C22:1 isomer fractions to investigate their individual effect on atherosclerosis and lipoprotein metabolism. LDLR-deficient (LDLr−/−) mice were fed a Western diet supplemented with 5% (w/w) of either C20:1 or C22:1 concentrate for 12 wk. ResultsCompared to the control Western diet with no supplement, both LCMUFA isomers increased hepatic levels of LCMUFA by 2∼3-fold (p < 0.05), and decreased atherosclerotic lesion areas by more than 40% (p < 0.05), although there were no major differences in plasma lipoproteins or hepatic lipid content. Both LCMUFA isomers significantly decreased plasma CRP levels, improved Abca1-dependent cholesterol efflux capacity of apoB-depleted plasma, and enhanced Ppar transcriptional activities in HepG2 cells. LC-MS/MS proteomic analysis of lipoproteins (HDL, LDL and VLDL) revealed that both LCMUFA isomer diets resulted in similar potentially beneficial alterations in proteins involved in complement activation, blood coagulation, and lipid metabolism. Several lipoprotein proteome changes were significantly correlated with atherosclerotic plaque reduction. ConclusionsDietary supplementation with the LCMUFA isomers C20:1 or C22:1 was equally effective in reducing atherosclerosis in LDLr−/−mice and this may partly occur through activation of the Ppar signaling pathways and favorable alterations in the proteome of lipoproteins.

Dietary long‐chain monounsaturated fatty acid (LCMUFA) as functional ingredient in fish oils: a novel approach for cardioprotection

Dietary long‐chain monounsaturated fatty acid (LCMUFA) as functional ingredient in fish oils: a novel approach for cardioprotection

Liver-specific mono-unsaturated fatty acid synthase-1 inhibitor for anti-hepatitis C treatment

Recently, direct antiviral agents against hepatitis C virus (HCV) infection have been developed as highly effective anti-HCV drugs. However, the appearance of resistant viruses against direct anti-viral agents is an unsolved problem. One of the strategies considered to suppress the emergence of the drug-resistant viruses is to use drugs inhibiting the host factor, which contributes to HCV proliferation, in combination with direct anti-viral agents. The replication complex was reported to be present in the membranous compartment in the cells. Thus, lipid metabolism modulators are good candidates to regulate virus assembly and HCV replication. Recent studies have shown that stearoyl-CoA desaturase (SCD), an enzyme for long-chain mono-unsaturated fatty acid (LCMUFA) synthesis, is a key factor that defines HCV replication efficiency. Systemic exposure to SCD-1 inhibor induces some side effects in the eyes and skin. Thus, systemic SCD-1 inhibitors are considered inappropriate for HCV therapy. To avoid the side effects of systemic SCD-1 inhibitors, the liver-specific SCD-1 inhibitor, MK8245, was synthesized; it showed antidiabetic effects in diabetic model mice with no side effects. In the phase 1 clinical study on measurement of MK8245 tolerability, no significant side effects were reported (ClinicalTrials.gov Identifier: NCT00790556). Therefore, we thought liver-specific SCD-1 inhibitors would be suitable agents for HCV-infected patients. MK8245 was evaluated using recombinant HCV culture systems. Considering current HCV treatments, to avoid the emergence of direct anti-viral agents-resistant viruses, combination therapy with direct anti-viral agents and host-targeted agents would be optimal. With this viewpoint, we confirmed MK8245’s additive or synergistic anti-HCV effects on current direct anti-viral agents and interferon-alpha therapy. The results suggest that MK8245 is an option for anti-HCV multi-drug therapy with a low risk of emergence of drug-resistant HCV without significant side effects.

Abstract 266: Role of Marine Long-chain Monounsaturated Fatty Acid in Cardiovascular Disease Prevention and Possible Mechanism to Reduce the Atherosclerosis

Numerous studies have shown cardiovascular benefits of fish oil, and most of these favorable effects have been attributed to omega-3 fatty acids. Fish oils, however, also contain varying amounts of other unusual types of fatty acids, such as long-chain monounsaturated fatty acids (LCMUFA; i.e., C20:1 and C22:1 isomers combined). Compared with well-studied omega-3, limited information is available on the role of LCMUFA on cardiovascular disease. In the current study, we examined the effect of saury fish oil-derived LCMUFA concentrate on the pathogenesis of atherosclerosis in ApoE-deficient and LDLR-deficient mice. Male ApoE-deficient mice were fed a western diet supplemented with 5% LCMUFA concentrate or not (control) for 12 weeks. En face Sudan IV staining of the aorta revealed that LCMUFA significantly suppressed the development of atherosclerotic lesions, and down-regulated inflammatory gene expression. In LDLR-deficient female mice, we also observed that 12-week supplementation of 2% LCMUFA on a western diet significantly decreased atherosclerosis lesion areas and accumulation of macrophages, compared with western diet (control) or western diet supplemented with 2% olive oil enriched in shorter-chain MUFA oleic acid (C18:1). There were no differences, however, in plasma or hepatic lipid profiles between the three groups. LCMUFA, but not olive oil, also significantly suppressed several plasma inflammatory cytokine levels. RNA sequencing and subsequent qPCR analyses revealed that LCMUFA upregulated PPAR signaling pathways in liver. In cell culture studies, apoB-depleted plasma from the LCMUFA group promoted cholesterol efflux from macrophage-like THP-1 cells and ABCA1-overexpressing BHK cells. LCMUFA also suppressed LPS-induced inflammatory cytokine production by macrophages. In conclusion, our research showed for the first time that LCMUFA consumption could protects against atherosclerosis, possibly by upregulating the PPAR signaling pathway. Omega-3 fatty acids are generally considered the major active components in fish lipids, but our findings provide new insights into potential health effect of LCMUFA-rich fish oil and suggest that LCMUFA-rich fish oil may also be beneficial for reducing cardiovascular disease risk.

Mobilisation of blubber fatty acids of northern elephant seal pups (Mirounga angustirostris) during the post-weaning fast

Northern elephant seal pups were longitudinally sampled at Año Nuevo State Reserve during the post-weaning fast, in order to evaluate the changes of fatty acid (FA) profiles in serum as well as in the inner and outer layers of blubber. The major FAs of inner and outer blubber layers were broadly similar to those found in NES maternal milk previously measured, suggesting a direct deposit of dietary FAs in the blubber during the suckling period. The outer blubber layer contained more medium-chain monounsaturated FAs that contribute in keeping the fluidity of this tissue at cold temperatures. It was compensated by higher proportions of saturated FAs in the inner blubber layer. The FA signature of inner blubber, the layer that is mainly mobilised during energy deprivation, slightly differed from the signature of serum. There were greater proportions of medium-chain saturated FAs and ω-6 polyunsaturated FAs, and lower proportions of long-chain saturated FAs, medium-chain monounsaturated FAs and long-chain monounsaturated FAs in serum as compared to inner blubber. We also demonstrated that lipophilicity is the main factor governing the mobilisation of FAs from blubber. The least lipophilic FAs were preferentially hydrolysed from blubber, leading to an enrichment of the more lipophilic FAs in this tissue with the progression of the fast. The expression levels of HSL and ATGL, which are two enzymes involved in the lipolytic process, remained stable during the post-weaning fast. This suggests that the pups have developed the enzymatic mechanisms for an efficient lipolysis as soon as the first week of fast.

Extraction and Characterization of Vegetable Oils from Cherry Seed by Different Extraction Processes

The aim of this work was to compare the content and composition of oil from cherry seeds using supercritical fluid extraction (SFE) using carbon dioxide as solvent, and Soxhlet extraction using diethyl ether. The compositions of free fatty acids and phytosterols, achieved with two extraction methods, were analyzed. Gas chromatographic analysis of unsaponifiables cherry seed oil samples, obtained with SFE and Soxhlet extraction, permitted to identify in particular two sterols, the s-sitosterol and campesterol. Brassicasterol or stigmasterol were not present in the extracts. The percentages of monitored components changed in function of extraction used procedure, allowing to assert that, with SFE, higher yield of phytosterols was provided. Preliminary data showed that there were significant differences also in the fatty acid composition of cherry seed oil obtained with the two extraction procedures (by means supercritical carbon dioxide or solvent). With the Soxhlet extraction, 48.6% of saturated fatty acids, 17.74% of unsaturated acids, 32.75% of polyunsaturated are obtained. On the contrary, with SFE decreased the percentage of saturated fatty acids (38.43%) in favor of larger amounts of unsaturated (19.93%) and polyunsaturated (36.04%). The supercritical fluid extraction procedure proved so effective in getting an oil of superior quality, without the possibility of degradation phenomena due to the solvent or heat. In both extraction procedures the cherry seed oil contained high percentages of arachidic acid (C20:0) and linoleic acid (C18:2, ?-6). An interesting result was also the presence of nervonic acid in remarkable amount, in all examined samples. Nervonic acid is a long-chain monounsaturated fatty acid (C24:1, ?-9), of marine origin, precursor of the neuronal cell membrane glycolipids, with a key role in the modulation of ion channels and membrane receptors, and therefore widely used as a neurotrophic factor in food supplements and nutraceuticals.

Abstract 061: Long-chain monounsaturated fatty acids and congestive heart failure incidence: the Atherosclerosis Risk in Communities Study

Background: Animal experiments in 1970s demonstrated direct cardiotoxicity of long-chain monounsaturated fatty acid (LCMUFA, 22:1 and 24:1 fatty acids) consumption. We recently found plasma phospholipid 22:1 and 24:1 to be associated with 34% and 75% higher risk (quintiles 5 vs. 1), respectively, of congestive heart failure (CHF) among older adults in the Cardiovascular Health Study. We wished to validate these results in a second independent cohort of middle-aged adults. Methods: We evaluated 3,577 adults free of CHF at baseline (age=54.1±5.8) in the Minnesota subcohort of the Atherosclerosis Risk in Communities Study (ARIC) in whom plasma phospholipid LCMUFA were measured. Incident CHF was ascertained from 1988 to 2008 by annual phone contacts, hospitalization discharge codes, and death certificates. Using multivariate Cox models, we evaluated prospective association of each LCMUFA with incident CHF, and potential mediation via CHF risk factors, including ECG left ventricular hypertrophy, and incident coronary heart disease (CHD). As a negative control, we also evaluated incident stroke, given its many shared risk factors for CHF but no link to potentially direct cardiotoxicity. Results: Mean±SD plasma phospholipid levels (% of total fatty acids) of 22:1 and 24:1 were 0.01±0.03 and 0.58±0.17. Over the 64,438 person-years of follow-up, 330 CHF events occurred. After multivariable adjustment, higher levels of 22:1 and 24:1 were associated with higher risk of CHF (Figure). Hazard ratios (95%CI) for quintiles 5 vs. 1 of 22:1 and 24:1 levels were 1.57 (1.11–2.23) and 1.92 (1.22–3.03) (p trend=0.03 and 0.002), respectively. These associations were only partly attenuated by potential mediators, including incident CHD. Neither LCMUFA was associated with incident stroke (not shown). Conclusions: Higher 22:1 and 24:1 LCMUFA levels were associated with CHF risk in middle-aged adults, consistent with our prior findings in older adults. These findings support the possibility of clinical cardiotoxicity of LCMUFA in humans.

Extraction, Identification, and Functional Characterization of a Bioactive Substance From Automated Compound-Handling Plastic Tips

Disposable plastic labware is ubiquitous in contemporary pharmaceutical research laboratories. Plastic labware is routinely used for chemical compound storage and during automated liquid-handling processes that support assay development, high-throughput screening, structure-activity determinations, and liability profiling. However, there is little information available in the literature on the contaminants released from plastic labware upon DMSO exposure and their resultant effects on specific biological assays. The authors report here the extraction, by simple DMSO washing, of a biologically active substance from one particular size of disposable plastic tips used in automated compound handling. The active contaminant was identified as erucamide ((Z)-docos-13-enamide), a long-chain mono-unsaturated fatty acid amide commonly used in plastics manufacturing, by gas chromatography/mass spectroscopy analysis of the DMSO-extracted material. Tip extracts prepared in DMSO, as well as a commercially obtained sample of erucamide, were active in a functional bioassay of a known G-protein-coupled fatty acid receptor. A sample of a different disposable tip product from the same vendor did not release detectable erucamide following solvent extraction, and DMSO extracts prepared from this product were inactive in the receptor functional assay. These results demonstrate that solvent-extractable contaminants from some plastic labware used in the contemporary pharmaceutical research and development (R&D) environment can be introduced into physical and biological assays during routine compound management liquid-handling processes. These contaminants may further possess biological activity and are therefore a potential source of assay-specific confounding artifacts.

Charge-Remote Metastable Ion Decomposition of Free Fatty Acids under FAB MS: Evidence for Biradical Ion Structures

Classical charge-remote fragmentation (CRF) of a series of long-chain saturated and monounsaturated fatty acid anions, a well-known phenomenon under collisional activation conditions, is observed for the first time during fast atom bombardment of the analyte-matrix mixture without collisional activation. The process is efficient enough to allow collision-induced dissociation and metastable ion decomposition MS/MS spectra of any charge-remote [M-H2-(CH2)n]- fragments as well as spectra of neutral losses to be recorded. The results obtained are in contradiction to the generally accepted theory that CRF results exclusively in terminally unsaturated carboxylate anions. The new results indicate that a multistep radical mechanism is involved in CRF ion formation. The first step of the process appears to be accompanied by hydrogen elimination that occurs randomly throughout the molecule. The primary fragment radical ions formed can decompose further with the formation of the next generation of CRF ions.

Fatty Acids Activate Transcription of the Muscle Carnitine Palmitoyltransferase I Gene in Cardiac Myocytes via the Peroxisome Proliferator-activated Receptor α

To explore the gene regulatory mechanisms involved in the metabolic control of cardiac fatty acid oxidative flux, the expression of muscle-type carnitine palmitoyltransferase I (M-CPT I) was characterized in primary cardiac myocytes in culture following exposure to the long-chain mono-unsaturated fatty acid, oleate. Oleate induced steady-state levels of M-CPT I mRNA 4.5-fold. The transcription of a plasmid construct containing the human M-CPT I gene promoter region fused to a luciferase gene reporter transfected into cardiac myocytes, was induced over 20-fold by long-chain fatty acid in a concentration-dependent and fatty acyl-chain length-specific manner. The M-CPT I gene promoter fatty acid response element (FARE-1) was localized to a hexameric repeat sequence located between 775 and 763 base pairs upstream of the initiator codon. Cotransfection experiments with expression vectors for the peroxisome proliferator-activated receptor alpha (PPARalpha) demonstrated that FARE-1 is a PPARalpha response element capable of conferring oleate-mediated transcriptional activation to homologous or heterologous promoters. Electrophoretic mobility shift assays demonstrated that PPARalpha bound FARE-1 with the retinoid X receptor alpha. The expression of M-CPT I in hearts of mice null for PPARalpha was approximately 50% lower than levels in wild-type controls. Moreover, a PPARalpha activator did not induce cardiac expression of the M-CPT I gene in the PPARalpha null mice. These results demonstrate that long-chain fatty acids regulate the transcription of a gene encoding a pivotal enzyme in the mitochondrial fatty acid uptake pathway in cardiac myocytes and define a role for PPARalpha in the control of myocardial lipid metabolism.

Digestion and absorption of polyunsaturated fatty acids

Polyunsaturated fatty acids play an important part in the structure and function of cellular membranes and are precursors of lipid mediators which play a key role in cardiovascular and inflammatory diseases. Dietary sources of essential fatty acids are vegetable oils for either linoleic or alpha-linolenic acids, and sea fish oils for eicosapentaenoic and docosahexaenoic acids. Because of the specificity of the pancreatic lipid hydrolases, triglyceride fatty acid distribution is an essential parameter in the digestibility of fats. The efficiency of the intestinal uptake depends on the hydrolysis and especially on their micellarization. n-3 polyunsaturated fatty acid ethyl ester digestion is recognized to be impaired, but n-3 polyunsaturated fatty acid triglyceride hydrolysis remains a controversial point, and to some authors explains differences observed between vegetable and fish oil absorption. So additional studies are required to investigate this intestinal step. In enterocytes, morphological and biochemical absorption processes involve reesterification of long-chain fatty acids and lipoprotein formation. At this level, specific affinity of I- and L-FABPc (cytosolic fatty acid binding proteins) to polyunsaturated fatty acids requires further investigation. A better understanding of the role of these FABPc might bring to light the esterification step, particularly the integration of polyunsaturated fatty acids into phospholipids. With reference to differences published between fish and vegetable oil absorption, longer-term absorption studies appear essential to some authors. Polyunsaturated fatty acid absorption is thought to be not very dissimilar to that of long-chain mono-unsaturated fatty acid absorption. However, several digestion and absorption specific steps are worth studying with reference to the crucial role of polyunsaturated fatty acids in the organism, and for example adaptation of possible dietary supplements.