Medium & long-chain acylcarnitine's relation to lipid metabolism as potential predictors for diabetic cardiomyopathy: a metabolomic study.

BACKGROUND: Acylcarnitine is an intermediate product of fatty acid oxidation. It is reported to be closely associated with the occurrence of diabetic cardiomyopathy (DCM). However, the mechanism of acylcarnitine affecting myocardial disorders is yet to be explored. This current research explores the different chain lengths of acylcarnitines as biomarkers for the early diagnosis of DCM and the mechanism of acylcarnitines for the development of DCM in-vitro. METHODS: In a retrospective non-interventional study, 50 simple type 2 diabetes mellitus patients and 50 DCM patients were recruited. Plasma samples from both groups were analyzed by high throughput metabolomics and cluster heat map using mass spectrometry. Principal component analysis was used to compare the changes occurring in the studied 25 acylcarnitines. Multivariable binary logistic regression was used to analyze the odds ratio of each group for factors and the 95% confidence interval in DCM. Myristoylcarnitine (C14) exogenous intervention was given to H9c2 cells to verify the expression of lipid metabolism-related protein, inflammation-related protein expression, apoptosis-related protein expression, and cardiomyocyte hypertrophy and fibrosis-related protein expression. RESULTS: Factor 1 (C14, lauroylcarnitine, tetradecanoyldiacylcarnitine, 3-hydroxyl-tetradecanoylcarnitine, arachidic carnitine, octadecanoylcarnitine, 3-hydroxypalmitoleylcarnitine) and factor 4 (octanoylcarnitine, hexanoylcarnitine, decanoylcarnitine) were positively correlated with the risk of DCM. Exogenous C14 supplementation to cardiomyocytes led to increased lipid deposition in cardiomyocytes along with the obstacles in adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathways and affecting fatty acid oxidation. This further caused myocardial lipotoxicity, ultimately leading to cardiomyocyte hypertrophy, fibrotic remodeling, and increased apoptosis. However, this effect was mitigated by the AMPK agonist acadesine. CONCLUSIONS: The increased plasma levels in medium and long-chain acylcarnitine extracted from factors 1 and 4 are closely related to the risk of DCM, indicating that these factors can be an important tool for DCM risk assessment. C14 supplementation associated lipid accumulation by inhibiting the AMPK/ACC/CPT1 signaling pathway, aggravated myocardial lipotoxicity, increased apoptosis apart from cardiomyocyte hypertrophy and fibrosis were alleviated by the acadesine.

Tetradecanoic Acids With Anti-Virulence Properties Increase the Pathogenicity of Pseudomonas aeruginosa in a Murine Cutaneous Infection Model.

Blocking virulence is a promising alternative to counteract Pseudomonas aeruginosa infections. In this regard, the phenomenon of cell-cell communication by quorum sensing (QS) is an important anti-virulence target. In this field, fatty acids (FA) have gained notoriety for their role as autoinducers, as well as anti-virulence molecules in vitro, like some saturated FA (SAFA). In this study, we analyzed the anti-virulence activity of SAFA with 12 to18 carbon atoms and compared their effect with the putative autoinducer cis-2-decenoic acid (CDA). The effect of SAFA on six QS-regulated virulence factors and on the secretion of the exoenzyme ExoU was evaluated. In addition, a murine cutaneous infection model was used to determine their influence on the establishment and damage caused by P. aeruginosa PA14. Dodecanoic (lauric, C12:0) and tetradecanoic (myristic, C14:0) acids (SAFA C12-14) reduced the production of pyocyanin by 35-58% at 40 and 1,000 µM, while CDA inhibited it 62% at a 3.1 µM concentration. Moreover, the SAFA C12-14 reduced swarming by 90% without affecting biofilm formation. In contrast, CDA reduced the biofilm by 57% at 3 µM but did not affect swarming. Furthermore, lauric and myristic acids abolished ExoU secretion at 100 and 50 µM respectively, while CDA reduced it by ≈ 92% at 100 µM. Remarkably, the coadministration of myristic acid (200 and 1,000 µM) with P. aeruginosa PA14 induced greater damage and reduced survival of the animals up to 50%, whereas CDA to 500 µM reduced the damage without affecting the viability of the PA14 strain. Hence, our results show that SAFA C12-14 and CDA have a role in regulation of P. aeruginosa virulence, although their inhibition/activation molecular mechanisms are different in complex environments such as in vivo systems.

Indole Reverses Intrinsic Antibiotic Resistance by Activating a Novel Dual-Function Importer.

Bacterial antibiotic resistance modulation by small signaling molecules is an emerging mechanism that has been increasingly reported in recent years. Several studies indicate that indole, an interkingdom signaling molecule, increases bacterial antibiotic resistance. However, the mechanism through which indole reduces antibiotic resistance is largely unknown. In this study, we demonstrated a novel mechanism for indole-mediated reversal of intrinsic antibiotic resistance in Lysobacter This reversal was facilitated by a novel BtuD-associated dual-function importer that can transfer both vitamin B12 and antibiotics. Indole stimulated btuD overexpression and promoted efficient absorption of extracellular vitamin B12; meanwhile, the weak selectivity of the importer caused cells to take up excessive doses of antibiotics that resulted in cell death. Consistently, btuD deletion and G48Y/K49D substitution led to marked reductions in the uptake of both antibiotics and vitamin B12 This novel mechanism is common across multiple bacterial species, among which the Q-loop amino acid of BtuD proteins is Glu (E) instead of Gln (Q). Interestingly, the antibiotic resistance of Lysobacter spp. can be restored by another small quorum sensing signaling factor, 13-methyltetradecanoic acid, designated LeDSF, in response to bacterial population density. This work highlights the mechanisms underlying dynamic regulation of bacterial antibiotic resistance by small signaling molecules and suggests that the effectiveness of traditional antibiotics could be increased by coupling them with appropriate signaling molecules.IMPORTANCE Recently, signaling molecules were found to play a role in mediating antibiotic resistance. In this study, we demonstrated that indole reversed the intrinsic antibiotic resistance (IRAR) of multiple bacterial species by promoting the expression of a novel dual-function importer. In addition, population-dependent behavior induced by 13-methyltetradecanoic acid, a quorum sensing signal molecule designated LeDSF, was involved in the IRAR process. This study highlights the dynamic regulation of bacterial antibiotic resistance by small signaling molecules and provides direction for new therapeutic strategies using traditional antibiotics in combination with signaling molecules.

Validation and Invalidation of Chemical Probes for the Human N-myristoyltransferases.

On-target, cell-active chemical probes are of fundamental importance in chemical and cell biology, whereas poorly characterized probes often lead to invalid conclusions. Human N-myristoyltransferase (NMT) has attracted increasing interest as target in cancer and infectious diseases. Here we report an in-depth comparison of five compounds widely applied as human NMT inhibitors, using a combination of quantitative whole-proteome N-myristoylation profiling, biochemical enzyme assays, cytotoxicity, in-cell protein synthesis, and cell-cycle assays. We find that N-myristoylation is unaffected by 2-hydroxymyristic acid (100 µM), D-NMAPPD (30 µM), or Tris-DBA palladium (10 µM), with the latter compounds causing cytotoxicity through mechanisms unrelated to NMT. In contrast, drug-like inhibitors IMP-366 (DDD85646) and IMP-1088 delivered complete and specific inhibition of N-myristoylation in a range of cell lines at 1 µM and 100 nM, respectively. This study enables the selection of appropriate on-target probes for future studies and suggests the need for reassessment of previous studies that used off-target compounds.

Monomyristin and Monopalmitin Derivatives: Synthesis and Evaluation as Potential Antibacterial and Antifungal Agents.

In the present work, monoacylglycerol derivatives, i.e., 1-monomyristin, 2-monomyristin, and 2-monopalmitin were successfully prepared from commercially available myristic acid and palmitic acid. The 1-monomyristin compound was prepared through a transesterification reaction between ethyl myristate and 1,2-O-isopropylidene glycerol, which was obtained from the protection of glycerol with acetone, then followed by deprotection using Amberlyst-15. On the other hand, 2-monoacylglycerol derivatives were prepared through enzymatic hydrolysis of triglycerides in the presence of Thermomyces lanuginosa lipase enzymes. The synthesized products were analyzed using fourier transform infrared (FTIR) spectrophotometer, gas or liquid chromatography-mass spectrometer (GC-MS or LC-MS), and proton and carbon nuclear magnetic resonance (¹H- and 13C-NMR) spectrometers. It was found that monomyristin showed high antibacterial and antifungal activities, while 2-monopalmitin did not show any activity at all. The 1-monomyristin compound showed higher antibacterial activity against Staphylococcus aureus and Aggregatibacter actinomycetemcomitans and also higher antifungal activity against Candida albicans compared to the positive control. Meanwhile, 2-monomyristin showed high antibacterial activity against Escherichia coli. The effect of the acyl position and carbon chains towards antibacterial and antifungal activities was discussed.

Identification of Inhibitory Compounds Against Singapore Grouper Iridovirus Infection by Cell Viability-Based Screening Assay and Droplet Digital PCR.

Singapore grouper iridovirus (SGIV) is one of the major causative agents of fish diseases and has caused significant economic losses in the aquaculture industry. There is currently no commercial vaccine or effective antiviral treatment against SGIV infection. Annually, an increasing number of small molecule compounds from various sources have been produced, and many are proved to be potential inhibitors against viruses. Here, a high-throughput in vitro cell viability-based screening assay was developed to identify antiviral compounds against SGIV using the luminescent-based CellTiter-Glo reagent in cultured grouper spleen cells by quantificational measurement of the cytopathic effects induced by SGIV infection. This assay was utilized to screen for potential SGIV inhibitors from five customized compounds which had been reported to be capable of inhibiting other viruses and 30 compounds isolated from various marine organisms, and three of them [ribavirin, harringtonine, and 2-hydroxytetradecanoic acid (2-HOM)] were identified to be effective on inhibiting SGIV infection, which was further confirmed with droplet digital PCR (ddPCR). In addition, the ddPCR results revealed that ribavirin and 2-HOM inhibited SGIV replication and entry in a dose-dependent manner, and harringtonine could reduce SGIV replication rather than entry at the working concentration without significant toxicity. These findings provided an easy and reliable cell viability-based screening assay to identify compounds with anti-SGIV effect and a way of studying the anti-SGIV mechanism of compounds.

Inhibition of enterovirus VP4 myristoylation is a potential antiviral strategy for hand, foot and mouth disease.

The Hand, Foot and Mouth Disease (HFMD) can result from infections by a plethora of human enteroviruses of the species Enterovirus A and B. These infections are highly contagious, resulting in regular outbreaks especially in the Asia-Pacific Region in the recent decade. Although this disease is generally a childhood affliction which manifests as a mild, febrile illness accompanied by the vesicles on the hands, feet and mouth, permanent morbidity or even fatality can result from severe forms of the disease in a subset of the infected patients. The N-terminal myristoylation signal (MGXXXS) of viral capsid protein VP4, one of the four viral structural proteins, is an extremely well conserved feature of enteroviruses, a potential antiviral target that may yield broad-spectrum inhibitors of HFMD. In this study, we have confirmed through the use of small interfering RNAs, human N-myristoyltransferase 1 plays an integral role in human Enterovirus 71 replication. Subsequent studies by inhibition of myristoylation using different myristic acid analogues elicited differential effects on the virus replication in human rhabdomyosarcoma cells. In particular, 2-hydroxymyristic acid specifically inhibited the cleavage between VP4 and VP2, part of the virion maturation process required to ensure infectivity of progeny virions while 4-oxatetradecanoic acid reduced the synthesis of viral RNA. These findings suggest that the requirement of a myristate moiety in viral structural protein precursor cleavage can serve as a viable antiviral target for further research.

Disturbance of mitochondrial functions provoked by the major long-chain 3-hydroxylated fatty acids accumulating in MTP and LCHAD deficiencies in skeletal muscle.

The pathogenesis of the muscular symptoms and recurrent rhabdomyolysis that are commonly manifested in patients with mitochondrial trifunctional protein (MTP) and long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) deficiencies is still unknown. In this study we investigated the effects of the major long-chain monocarboxylic 3-hydroxylated fatty acids (LCHFA) accumulating in these disorders, namely 3-hydroxytetradecanoic (3HTA) and 3-hydroxypalmitic (3HPA) acids, on important mitochondrial functions in rat skeletal muscle mitochondria. 3HTA and 3HPA markedly increased resting (state 4) and decreased ADP-stimulated (state 3) and CCCP-stimulated (uncoupled) respiration. 3HPA provoked similar effects in permeabilized skeletal muscle fibers, validating the results obtained in purified mitochondria. Furthermore, 3HTA and 3HPA markedly diminished mitochondrial membrane potential, NAD(P)H content and Ca(2+) retention capacity in Ca(2+)-loaded mitochondria. Mitochondrial permeability transition (mPT) induction probably underlie these effects since they were totally prevented by cyclosporin A and ADP. In contrast, the dicarboxylic analogue of 3HTA did not alter the tested parameters. Our data strongly indicate that 3HTA and 3HPA behave as metabolic inhibitors, uncouplers of oxidative phosphorylation and mPT inducers in skeletal muscle. It is proposed that these pathomechanisms disrupting mitochondrial homeostasis may be involved in the muscle alterations characteristic of MTP and LCHAD deficiencies.

Mitochondrial bioenergetics deregulation caused by long-chain 3-hydroxy fatty acids accumulating in LCHAD and MTP deficiencies in rat brain: a possible role of mPTP opening as a pathomechanism in these disorders?

Long-chain 3-hydroxylated fatty acids (LCHFA) accumulate in long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) and mitochondrial trifunctional protein (MTP) deficiencies. Affected patients usually present severe neonatal symptoms involving cardiac and hepatic functions, although long-term neurological abnormalities are also commonly observed. Since the underlying mechanisms of brain damage are practically unknown and have not been properly investigated, we studied the effects of LCHFA on important parameters of mitochondrial homeostasis in isolated mitochondria from cerebral cortex of developing rats. 3-Hydroxytetradecanoic acid (3 HTA) reduced mitochondrial membrane potential, NAD(P)H levels, Ca(2+) retention capacity and ATP content, besides inducing swelling, cytochrome c release and H2O2 production in Ca(2+)-loaded mitochondrial preparations. We also found that cyclosporine A plus ADP, as well as ruthenium red, a Ca(2+) uptake blocker, prevented these effects, suggesting the involvement of the mitochondrial permeability transition pore (mPTP) and an important role for Ca(2+), respectively. 3-Hydroxydodecanoic and 3-hydroxypalmitic acids, that also accumulate in LCHAD and MTP deficiencies, similarly induced mitochondrial swelling and decreased ATP content, but to a variable degree pending on the size of their carbon chain. It is proposed that mPTP opening induced by LCHFA disrupts brain bioenergetics and may contribute at least partly to explain the neurologic dysfunction observed in patients affected by LCHAD and MTP deficiencies.

13-methyltetradecanoic acid exhibits anti-tumor activity on T-cell lymphomas in vitro and in vivo by down-regulating p-AKT and activating caspase-3.

13-Methyltetradecanoic acid (13-MTD), a saturated branched-chain fatty acid purified from soy fermentation products, induces apoptosis in human cancer cells. We investigated the inhibitory effects and mechanism of action of 13-MTD on T-cell non-Hodgkin's lymphoma (T-NHL) cell lines both in vitro and in vivo. Growth inhibition in response to 13-MTD was evaluated by the cell counting kit-8 (CCK-8) assay in three T-NHL cell lines (Jurkat, Hut78, EL4 cells). Flow cytometry analyses were used to monitor the cell cycle and apoptosis. Proteins involved in 13-MTD-induced apoptosis were examined in Jurkat cells by western blotting. We found that 13-MTD inhibited proliferation and induced the apoptosis of T-NHL cell lines. 13-MTD treatment also induced a concentration-dependent arrest of Jurkat cells in the G1-phase. During 13-MTD-induced apoptosis in Jurkat cells, the cleavage of caspase-3 and poly ADP-ribose polymerase (PARP, a caspase enzymolysis product) were detected after incubation for 2 h, and increased after extending the incubation time. However, there was no change in the expression of Bcl-2 or c-myc proteins. The appearance of apoptotic Jurkat cells was accompanied by the inhibition of AKT and nuclear factor-kappa B (NF-κB) phosphorylation. In addition, 13-MTD could also effectively inhibit the growth of T-NHL tumors in vivo in a xenograft model. The tumor inhibition rate in the experimental group was 40%. These data indicate that 13-MTD inhibits proliferation and induces apoptosis through the down-regulation of AKT phosphorylation followed by caspase activation, which may provide a new approach for treating T-cell lymphomas.

Chaperone properties of pdia3 participate in rapid membrane actions of 1α,25-dihydroxyvitamin d3.

Protein disulfide isomerase family A, member 3 (Pdia3) mediates many of the plasma membrane (PM)-associated rapid responses to 1α,25-dihydroxyvitamin D3 (1α,25[OH]2D3). It is not well understood how Pdia3, which is an endoplasmic reticulum (ER) chaperone, functions as a PM receptor for 1α,25(OH)2D3. We mutated 3 amino acids (K214 and R282 in the calreticulin interaction site and C406 in the isomerase catalytic site), which are important for Pdia3's ER chaperone function, and examined their role in responses to 1α,25(OH)2D3. Pdia3 constructs with and without the ER retention signal KDEL were used to investigate the PM requirement for Pdia3. Finally, we determined whether palmitoylation and/or myristoylation were required for Pdia3-mediated responses to 1α,25(OH)2D3. Overexpressing the Pdia3 R282A mutant in MC3T3-E1 cells increased PM phospholipase A2-activating protein, Rous sarcoma oncogene (c-Src), and caveolin-1 but blocked increases in 1α,25(OH)2D3-stimulated protein kinase C (PKC) seen in cells overexpressing wild-type Pdia3 (Pdia3Ovr cells). Cells overexpressing Pdia3 with K214A and C406S mutations had PKC activity comparable to untreated controls, indicating that the native response to 1α,25(OH)2D3 also was blocked. Overexpressing Pdia3[-KDEL] increased PM localization and augmented baseline PKC, but the stimulatory effect of 1α,25(OH)2D3 was comparable to that seen in wild-type cultures. In contrast, 1α,25(OH)2D3 increased prostaglandin E2 in Pdia3[±KDEL] cells. Although neither palmitoylation nor myristoylation was required for PM association of Pdia3, myristoylation was needed for PKC activation. These data indicate that both the chaperone functional domains and the subcellular location of Pdia3 control rapid membrane responses to 1α,25(OH)2D3.

Melanogenesis of methyl myristate loaded niosomes in B16F10 melanoma cells.

The objective of this study was to compare the charge effect of methyl myristate loaded in neutral (Brij 72/cholesterol at 7:3), cationic (Brij 72/cholesterol/dimethyl dioctadecyl ammonium bromide at 7:3:0.65) and anionic niosomes (Brij 72/cholesterol/dicetyl phosphate at 7:3:0.65) for physicochemical characteristics, cytotoxicity in fibroblasts and B16F10 melanoma cells as well as melanogenesis induction activity. The maximum loading and percentage entrapment of methyl myristate were 4.5, 90.68 +/- 7.95 in neutral; 11.0, 92.54 +/- 6.32 in cationic and 0.1% w/w, 74.43 +/- 1.86% in anionic niosomes, respectively. All methyl myristate loaded niosomes were in unilamellar structure under transmission electron microscope and in nanosize at initial and after 3-month storage. The percentages of methyl myristate remaining in all niosomes kept at 4 +/- 2, 30 +/- 2 and 45 +/- 2 degrees C for 3 months were about 82, 74 and 72%, respectively, while the dry free methyl myristate indicated 97.82 +/- 1.74, 96.56 +/- 2.91 and 91.39 +/- 4.32%, respectively. Blank neutral, blank cationic and methyl myristate loaded neutral and cationic niosomes exhibited moderate cytotoxicity in fibroblasts and B16F10 melanoma cells at 56.64 +/- 3.19, 59.72 +/- 1.51; 73.81 +/- 2.86, 82.51 +/- 0.20; 47.34 +/- 2.13, 52.67 +/-2.78 and 73.20 +/- 3.49, 84.34 +/- 2.75% cell viability, respectively. Blank anionic and methyl myristate loaded anionic niosomes indicated no cytotoxicity in both cells. Cytotoxic ratio of cell viability in normal and cancer cells of all niosomes indicated no toxic effect to normal cells. Methyl myristate loaded cationic niosomes demonstrated the highest melanin induction with tyrosinase activity of 1.42 and 1.70 folds of the control and 1.14 and 1.59 folds higher than theophylline, respectively. This study has suggested the potential of methyl myristate loaded cationic niosomes for canities treatment.

Synthesis and anti-HIV activities of glutamate and peptide conjugates of nucleoside reverse transcriptase inhibitors.

Mono-, di-, and trinucleoside conjugates of glutamate or peptide scaffolds containing nucleoside reverse transcriptase inhibitors were synthesized. Among dinucleoside glutamate ester derivatives, N-myristoylated derivatives showed significantly higher anti-HIV activity than the corresponding N-acetylated conjugates against cell-free virus. Myristoyl-Glu(3TC)-FLT (46, EC(50) = 0.3-0.6 µM) and myristoyl-Glu(FTC)-FLT (47, EC(50) = 0.1-0.4 µM) derivatives were the most active glutamate-dinucleoside conjugates. A trinucleoside glutamate derivative containing AZT, FLT, and 3TC (34, EC(50) = 0.9-1.4 µM) exhibited higher anti-HIV activity than AZT and 3TC against cell-free virus. Compound 34 also exhibited higher anti-HIV activity against multidrug (IC(50) = 5.9 nM) and NNRTI (IC(50) = 12.9 nM) resistant viruses than parent nucleosides. The physical mixture containing FLT-succinate, AZT, 3TC, and glutamic acid exhibited 115-fold less activity against cell associated virus (EC(50) = 91.9 µM) when compared to 34 (EC(50) = 0.8 µM). Other conjugates showed less or comparable potency to that of the corresponding physical mixtures.

13-Methyltetradecanoic acid induces mitochondrial-mediated apoptosis in human bladder cancer cells.

OBJECTIVE: 13-Methyltetradecanoic acid (13-MTD), a saturated branched-chain fatty acid purified from soy fermentation products, is known to induce apoptosis in many types of human cancer cells. This study was designed to investigate the molecular mechanisms involved in 13-MTD-induced apoptosis in human bladder cancer cells. METHODS AND MATERIALS: MTT assay was used to investigate the potential effects of 13-MTD on the growth and viability of human bladder cancer cells. To find out whether anti-proliferation and cell death were associated with apoptosis, we used flow cytometry to quantify the extent of apoptosis and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay to measures DNA degradation of apoptotic cells. The proteins involved in the 13-MTD induced apoptosis were examined using Western blot. RESULTS: We show that 13-MTD inhibits cellular proliferation and viability in human bladder cancer cells, which has been attributed to apoptosis. 13-MTD down-regulates Bcl-2 and up-regulates Bax. This promotes mitochondrial dysfunction, leading to the release of cytochrome c from the mitochondria to the cytoplasm, as well as the proteolytic activation of caspases. Moreover, 13-MTD down-regulates AKT phosphorylation and activates phosphorylation of p38 and c-Jun N-terminal kinase (JNK). Up-regulating AKT phosphorylation and down-regulating JNK and P38 phosphorylation could attenuate the13-MTD-induced apoptosis. CONCLUSION: Taken together, these data indicate that 13-MTD induces mitochondrial-mediated apoptosis through regulation of the AKT and MAPK pathways, suggesting 13-MTD is a potential candidate for treatment of human bladder cancer.

Activation of hydrogen peroxide to peroxytetradecanoic acid is responsible for potent inhibition of protein tyrosine phosphatase CD45.

Hydrogen peroxide induces oxidation and consequently inactivation of many protein tyrosine phosphatases. It was found that hydrogen peroxide, in the presence of carboxylic acids, was efficiently activated to form even more potent oxidant - peroxy acid. We have found that peroxytetradecanoic acid decreases the enzymatic activity of CD45 phosphatase significantly more than hydrogen peroxide. Our molecular docking computational analysis suggests that peroxytetradecanoic acid has a higher binding affinity to the catalytic center of CD45 than hydrogen peroxide.

Diets high in palmitic acid (16:0), lauric and myristic acids (12:0 + 14:0), or oleic acid (18:1) do not alter postprandial or fasting plasma homocysteine and inflammatory markers in healthy Malaysian adults.

BACKGROUND: Dietary fat type is known to modulate the plasma lipid profile, but its effects on plasma homocysteine and inflammatory markers are unclear. OBJECTIVE: We investigated the effects of high-protein Malaysian diets prepared with palm olein, coconut oil (CO), or virgin olive oil on plasma homocysteine and selected markers of inflammation and cardiovascular disease (CVD) in healthy adults. DESIGN: A randomized-crossover intervention with 3 dietary sequences of 5 wk each was conducted in 45 healthy subjects. The 3 test fats, namely palmitic acid (16:0)-rich palm olein (PO), lauric and myristic acid (12:0 + 14:0)-rich CO, and oleic acid (18:1)-rich virgin olive oil (OO), were incorporated at two-thirds of 30% fat calories into high-protein Malaysian diets. RESULTS: No significant differences were observed in the effects of the 3 diets on plasma total homocysteine (tHcy) and the inflammatory markers TNF-α, IL-1ß, IL-6, and IL-8, high-sensitivity C-reactive protein, and interferon-γ. Diets prepared with PO and OO had comparable nonhypercholesterolemic effects; the postprandial total cholesterol for both diets and all fasting lipid indexes for the OO diet were significantly lower (P < 0.05) than for the CO diet. Unlike the PO and OO diets, the CO diet was shown to decrease postprandial lipoprotein(a). CONCLUSION: Diets that were rich in saturated fatty acids prepared with either PO or CO, and an OO diet that was high in oleic acid, did not alter postprandial or fasting plasma concentrations of tHcy and selected inflammatory markers. This trial was registered at clinicaltrials.gov as NCT00941837.

Fatty acids identified in the Burmese python promote beneficial cardiac growth.

Burmese pythons display a marked increase in heart mass after a large meal. We investigated the molecular mechanisms of this physiological heart growth with the goal of applying this knowledge to the mammalian heart. We found that heart growth in pythons is characterized by myocyte hypertrophy in the absence of cell proliferation and by activation of physiological signal transduction pathways. Despite high levels of circulating lipids, the postprandial python heart does not accumulate triglycerides or fatty acids. Instead, there is robust activation of pathways of fatty acid transport and oxidation combined with increased expression and activity of superoxide dismutase, a cardioprotective enzyme. We also identified a combination of fatty acids in python plasma that promotes physiological heart growth when injected into either pythons or mice.

Effects of lauric and myristic acids on ruminal fermentation, production, and milk fatty acid composition in lactating dairy cows.

The objectives of this experiment were to investigate the effects of lauric (LA) and myristic (MA) acids on ruminal fermentation, production, and milk fatty acid (FA) profile in lactating dairy cows and to identify the FA responsible for the methanogen-suppressing effect of coconut oil. The experiment was conducted as a replicated 3×3 Latin square. Six ruminally cannulated cows (95±26.4 DIM) were subjected to the following treatments: 240 g/cow per day each of stearic acid (SA, control), LA, or MA. Experimental periods were 28 d and cows were refaunated between periods. Lauric acid reduced protozoal counts in the rumen by 96%, as well as acetate, total VFA, and microbial N outflow from the rumen, compared with SA and MA. Ruminal methane production was not affected by treatment. Dry matter intake was reduced 35% by LA compared with SA and MA, which resulted in decreased milk yield. Milk fat content also was depressed by LA compared with SA and MA. Treatment had no effect on milk protein content. All treatments increased milk concentration of the respective treatment FA. Concentration of C12:0 was more than doubled by LA, and C14:0 was increased (45%) by MA compared with SA. Concentration of milk FAC16 FA and MUFA were increased, by LA compared with the other treatments. In this study, LA had profound effects on ruminal fermentation, mediated through inhibited microbial populations, and decreased DMI, milk yield, and milk fat content. Despite the significant decrease in protozoal counts, however, LA had no effect on ruminal methane production. Thus, the antimethanogenic effect of coconut oil, observed in related studies, is likely due to total FA application level, the additive effect of LA and MA, or a combination of both. Both LA and MA modified milk FA profile significantly.

Evaluation of an oviposition-stimulating kairomone for the yellow fever mosquito, Aedes aegypti, in Recife, Brazil.

A synthetic mixture of an oviposition-stimulating kairomone for the yellow fever mosquito, Aedes aegypti, comprising of 83% tetradecanoic acid, 16% nonanoic acid and 1% tetradecanoic acid methyl ester (NTT, in short) was tested in a dengue endemic area in Recife, Brazil. Gravid female mosquitoes confined to a cage under semi-field conditions deposited significantly higher numbers of eggs in traps baited with NTT at doses ranging from 0.6 to 600 ng/microl than in control (water) traps. When tested in homes, egg-laying in traps baited with 60 ng NTT/microl (final concentration in trap, approximately 3.33 ng/ml) and in control traps was not significantly different, but egg deposited in traps with lower dosage (6 ng NTT/microl; final concentration in trap, approximately 0.33 ng/ml) was significantly higher than in control traps. In subsequent trials, the numbers of eggs laid in traps baited with 0.6 ng NTT/microl (final concentration in trap, approximately 0.033 ng/ml) were not significantly different from the numbers deposited in trap loaded with 6 ng NTT/microl. Egg-laying was significantly higher in these treatments than in control traps.