Pharmacological inhibition of ENT1 enhances the impact of specific dietary fats on energy metabolism gene expression.

Medium chain fatty acids are commonly consumed as part of diets for endurance sports and as medical treatment in ketogenic diets where these diets regulate energy metabolism and increase adenosine levels. However, the role of the equilibrative nucleoside transporter 1 (ENT1), which is responsible for adenosine transport across membranes in this process, is not well understood. Here, we investigate ENT1 activity in controlling the effects of two dietary medium chain fatty acids (decanoic and octanoic acid), employing the tractable model system Dictyostelium. We show that genetic ablation of three ENT1 orthologues unexpectedly improves cell proliferation specifically following decanoic acid treatment. This effect is not caused by increased adenosine levels triggered by both fatty acids in the presence of ENT1 activity. Instead, we show that decanoic acid increases expression of energy-related genes relevant for fatty acid ß-oxidation, and that pharmacological inhibition of ENT1 activity leads to an enhanced effect of decanoic acid to increase expression of tricarboxylicacid cycle and oxidative phosphorylation components. Importantly, similar transcriptional changes have been shown in the rat hippocampus during ketogenic diet treatment. We validated these changes by showing enhanced mitochondria load and reduced lipid droplets. Thus, our data show that ENT1 regulates the medium chain fatty acid-induced increase in cellular adenosine levels and the decanoic acid-induced expression of important metabolic enzymes in energy provision, identifying a key role for ENT1 proteins in metabolic effects of medium chain fatty acids.

No Effects of Decanoic Acid on Locomotor Activity and Antioxidant Defences in an Experimental Animal Model of Attention-Deficit/Hyperactivity Disorder.

BACKGROUND: Medium-chain triglycerides such as decanoic acid (C10), which is one of the fatty acids that constitute dietary fats, are of substantial interest for their potential therapeutic effects on neuropsychiatric disorders. However, the effects of C10 on attention-deficit/hyperactivity disorder (ADHD) remain to be studied. We explored the effects of C10 on behavioural activity and antioxidant defences in an experimental animal model of ADHD. METHODS: To establish an experimental animal model of ADHD, neonatal rats were subjected to unilateral striatal lesions using 6-hydroxydopamine (6-OHDA). The rats sequentially underwent open-field and Y-maze tests before treatment [postnatal day 25 (PN25)]. After the subcutaneous administration of either vehicle or C10 solution (250 mg/kg) for 14 days, the behavioural tests were repeated on PN39. Next, we examined the effects of C10 on the expression of the constitutive antioxidant enzymes catalase and glutathione peroxidase-1/2 and the phase II transcription factor nuclear factor erythroid 2-related factor 2 in four different regions of the rat brain. RESULTS: Injection of 6-OHDA unilaterally into the striatum resulted in elevated locomotor activity on PN39. The administration of C10 for a period of 14 days did not alter the locomotor hyperactivity. Moreover, the administration of C10 had no significant effects on the expression of proteins related to antioxidant defences in the hippocampus, prefrontal cortex, striatum or cerebellum of both control and lesioned rats. CONCLUSIONS: The lack of significant effects of C10 in our study may depend on the dose and duration of C10 administration. Further exhaustive studies are needed to verify the efficacy and effects of different doses and treatment durations of C10 and to explore the underlying mechanisms.

ß-Hydroxybutyrate and Medium-Chain Fatty Acids are Metabolized by Different Cell Types in Mouse Cerebral Cortex Slices.

Ketogenic diets and medium-chain triglycerides are gaining attention as treatment of neurological disorders. Their major metabolites, ß-hydroxybutyrate (ßHB) and the medium-chain fatty acids (MCFAs) octanoic acid (C8) and decanoic acid (C10), are auxiliary brain fuels. To which extent these fuels compete for metabolism in different brain cell types is unknown. Here, we used acutely isolated mouse cerebral cortical slices to (1) compare metabolism of 200 µM [U-13C]C8, [U-13C]C10 and [U-13C]ßHB and (2) assess potential competition between metabolism of ßHB and MCFAs by quantifying metabolite 13C enrichment using gas chromatography-mass spectrometry (GC-MS) analysis. The 13C enrichment in most metabolites was similar with [U-13C]C8 and [U-13C]C10 as substrates, but several fold lower with [U-13C]ßHB. The 13C enrichment in glutamate was in a similar range for all three substrates, whereas the 13C enrichments in citrate and glutamine were markedly higher with both [U-13C]C8 and [U-13C]C10 compared with [U-13C]ßHB. As citrate and glutamine are indicators of astrocytic metabolism, the results indicate active MCFA metabolism in astrocytes, while ßHB is metabolized in a different cellular compartment. In competition experiments, 12C-ßHB altered 13C incorporation from [U-13C]C8 and [U-13C]C10 in only a few instances, while 12C-C8 and 12C-C10 only further decreased the low [U-13C]ßHB-derived 13C incorporation into citrate and glutamine, signifying little competition for oxidative metabolism between ßHB and the MCFAs. Overall, the data demonstrate that ßHB and MCFAs are supplementary fuels in different cellular compartments in the brain without notable competition. Thus, the use of medium-chain triglycerides in ketogenic diets is likely to be beneficial in conditions with carbon and energy shortages in both astrocytes and neurons, such as GLUT1 deficiency.

Synomones in necrophagous larvae of the blow flies Lucilia sericata and Calliphora vomitoria.

Chemical signals are widespread in insects, but those resulting in interspecific communication (i.e., synomones) remain understudied. Here, we analysed chemicals left on substrates by two species of blow fly larvae, Lucilia sericata (Meigen) and Calliphora vomitoria (Linneaus) (Diptera: Calliphoridae), which can aggregate together on carrion. Using solid-phase microextraction and dynamic headspace analysis, we identified six compounds common to both species: the decanoic, tetradecanoic, pentadecanoic, hexadecanoic and octadecanoic acids, and the 2-ethylhexyl salicylate. We then tested the behavioural effects of the decanoic and pentadecanoic acids using binary-choice experiments, along with the (Z)-9-tricosene, a pheromone found in many arthropods. The time spent by a larva and its average crawling speed were measured in two sides of an arena, where only one contained a compound at 0.25 or 25 µg/µl. No effect was observed when testing the decanoic acid. The pentadecanoic acid only reduced the speed of C. vomitoria larvae at 25 µg/µl. Finally, L. sericata larvae spent less time in the side containing the (Z)-9-tricosene at 0.25 µg/µl, whereas C. vomitoria spent more time and crawled faster in this side at 25 µg/µl. Although these results did not directly evidence synomones, they suggest that the (Z)-9-tricosene could regulate larval aggregations on carrion.

Decanoic acid inhibits mTORC1 activity independent of glucose and insulin signaling.

Low-glucose and -insulin conditions, associated with ketogenic diets, can reduce the activity of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway, potentially leading to a range of positive medical and health-related effects. Here, we determined whether mTORC1 signaling is also a target for decanoic acid, a key component of the medium-chain triglyceride (MCT) ketogenic diet. Using a tractable model system, Dictyostelium, we show that decanoic acid can decrease mTORC1 activity, under conditions of constant glucose and in the absence of insulin, measured by phosphorylation of eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1). We determine that this effect of decanoic acid is dependent on a ubiquitin regulatory X domain-containing protein, mediating inhibition of a conserved Dictyostelium AAA ATPase, p97, a homolog of the human transitional endoplasmic reticulum ATPase (VCP/p97) protein. We then demonstrate that decanoic acid decreases mTORC1 activity in the absence of insulin and under high-glucose conditions in ex vivo rat hippocampus and in tuberous sclerosis complex (TSC) patient-derived astrocytes. Our data therefore indicate that dietary decanoic acid may provide a new therapeutic approach to down-regulate mTORC1 signaling.

Decanoic acid mitigates ischemia reperfusion injury by modulating neuroprotective, inflammatory and oxidative pathways in middle cerebral artery occlusion model of stroke in rats.

OBJECTIVE: Amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) is an ionotropic transmembrane receptor for glutamate. AMPA receptor blockers have been reported to prevent neurological damage and enhance the post stroke recovery in rats. Decanoic acid, a medium-chain fatty acid, has been reported to exhibit non-competitive AMPA receptor antagonism. This study evaluated the effect of decanoic acid administered before and after ischemia reperfusion injury on neurological damage and post stroke recovery in rats. METHODS: Middle cerebral artery occlusion (MCAo) was performed by using the intraluminal method to induce focal cerebral ischemia. Decanoic acid (120 mg/kg) was administered orally for 1 day (5-10 min post reperfusion) in one group and for 2 days (24 h pre and 5-10 min post reperfusion) in the other group. Effect on neurological damage and post stroke recovery was assessed by neurobehavioral parameters, MRI and TTC staining along with inflammatory, oxidative, apoptotic, and neuroprotective biomarkers. RESULTS: Decanoic acid significantly reduced the MCAo induced neurological damage and infarct size. Decanoic acid treatment increased the motor coordination and grip strength. Furthermore, levels of inflammatory (TNFα, IL-1ß and IL-6), oxidative stress (MDA), apoptotic (TUNEL positive cells) and neurological injury (GFAP) biomarkers were reduced after decanoic acid treatment. Anti-inflammatory cytokine (IL-10) and neuroprotective markers (NT-3, BDNF and TrkB) were found to be significantly increased with decanoic acid treatment. CONCLUSION: This study showed protective effects of decanoic acid against ischemia reperfusion injury in rats. Anti-inflammatory, antioxidant, neuroprotective, and anti-apoptotic properties may be responsible for the beneficial effects of decanoic acid observed in the study.

Non-Covalent Assembly of Multiple Fluorophores in Edible Protein/Lipid Hydrogels for Applications in Multi-Step Light Harvesting and White-Light Emission.

The design and production of biodegradable and sustainable non-toxic materials for solar-energy harvesting and conversion is a significant challenge. Here, our goal was to report the preparation of novel protein/lipid hydrogels and demonstrate their utility in two orthogonal fundamental studies-light harvesting and white-light emission. Our hydrogels contained up to 90% water, while also being self-standing and injectable with a syringe. In one application, we loaded these hydrogels with suitable organic donor-acceptor dyes and demonstrated the energy-transfer cascade among four different dyes, with the most red-emitting dye as the energy destination. We hypothesized that the dyes were embedded in the protein/lipid phase away from the water pools as monomeric entities and that the excitation of any of the four dyes resulted in intense emission from the lowest-energy acceptor. In contrast to the energy-transfer cascade, we demonstrate the use of these gels to form a white-light-emitting hydrogel dye assembly, in which excitation migration is severely constrained. By restricting the dye-to-dye energy transfer, the blue, green, and red dyes emit at their respective wavelengths, thereby producing the composite white-light emission. The CIE color coordinates of the emission were 0.336 and 0.339-nearly pure white-light emission. Thus, two related studies with opposite requirements could be accommodated in the same hydrogel, which was made from edible ingredients by a simple method. These gels are biodegradable when released into the environment, sustainable, and may be of interest for energy applications.

Hydroxycarboxylic acid receptor 3 and GPR84 - Two metabolite-sensing G protein-coupled receptors with opposing functions in innate immune cells.

G protein-coupled receptors (GPCRs) are key regulatory proteins of immune cell function inducing signaling in response to extracellular (pathogenic) stimuli. Although unrelated, hydroxycarboxylic acid receptor 3 (HCA3) and GPR84 share signaling via Gαi/o proteins and the agonist 3-hydroxydecanoic acid (3HDec). Both receptors are abundantly expressed in monocytes, macrophages and neutrophils but have opposing functions in these innate immune cells. Detailed insights into the molecular mechanisms and signaling components involved in immune cell regulation by GPR84 and HCA3 are still lacking. Here, we report that GPR84-mediated pro-inflammatory signaling depends on coupling to the hematopoietic cell-specific Gα15 protein in human macrophages, while HCA3 exclusively couples to Gαi protein. We show that activated GPR84 induces Gα15-dependent ERK activation, increases intracellular Ca2+ and IP3 levels as well as ROS production. In contrast, HCA3 activation shifts macrophage metabolism to a less glycolytic phenotype, which is associated with anti-inflammatory responses. This is supported by an increased release of anti-inflammatory IL-10 and a decreased secretion of pro-inflammatory IL-1ß. In primary human neutrophils, stimulation with HCA3 agonists counteracts the GPR84-induced neutrophil activation. Our analyses reveal that 3HDec acts solely through GPR84 but not HCA3 activation in macrophages. In summary, this study shows that HCA3 mediates hyporesponsiveness in response to metabolites derived from dietary lactic acid bacteria and uncovers that GPR84, which is already targeted in clinical trials, promotes pro-inflammatory signaling via Gα15 protein in macrophages.

Protective effects of medium chain triglyceride diet in a mouse model of Dravet syndrome.

OBJECTIVE: Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy with early childhood onset. Patients with DS do not respond well to antiepileptic drugs and have only a few treatment options available. Here, we evaluated the effect of medium chain triglyceride (MCT) diet therapy in a mouse model of DS. METHODS: Scn1aR1407X/+ DS mice were given diets supplemented with MCTs with varying ratios of decanoic (C10) and octanoic (C8) acid or a control diet for 4 weeks. Video monitoring was performed to evaluate spontaneous convulsive seizure frequency. Susceptibility to hyperthermia-induced seizures was also examined. Medium chain fatty acids, and mitochondrial and antioxidant markers were assessed in brain homogenate. RESULTS: Dietary intervention with MCTs significantly prolonged survival and reduced convulsive seizure frequency during the critical period of highest seizure occurrence in the Scn1aR1407X/+ DS mice. Moreover, MCT diet therapy showed protective effects against hyperthermia-induced seizures. We demonstrated that coadministration of C10/C8 was effective at reducing both seizures and mortality, whereas C10 alone only reduced mortality, suggesting that the ratio of C10 to C8 in the MCT is an important factor for efficacy. When C10 and C8 are supplemented at an 80:20 ratio in the diet, C10 accumulates in the brain in high enough concentrations to enhance brain energy metabolism by both stimulating mitochondrial enrichment and increasing its antioxidant status. SIGNIFICANCE: The results from this study indicate that MCT diet therapy may provide therapeutic benefits in DS. Future clinical studies would elucidate whether these positive effects are mirrored in human patients.

Identification of a novel humoral antifungal defense molecule in the hemolymph of tasar silkworm Antheraea mylitta.

Humoral defenses are the major components of insect innate immune system that include the production of several soluble effector molecules from fat body and hemocytes, and released in to the hemolymph upon microbial infection. Hemolymph was collected from the fungal immunized fifth instar larvae of tasar silkworm, Antheraea mylitta, extracted with a mixture of solvent (methanol/glacial acetic acid/water) and fractionated through RP-HPLC. Several fractions were collected, lyophilized and their antifungal activity was tested against Candida albicans. Only the fraction showing strong antifungal activity was further purified via gel filtration chromatography and the purity of active compound was confirmed by thin layer chromatography which showed only single spot after staining with ninhydrin. The molecular mass of this purified compound was determined by high resolution mass spectrometry as 531 Da and analysis of 1H and 13C NMR spectral data along with mass fragmentation pattern indicated the probable structure of the isolated compound as symmetric bis-decanoate derivative. Scanning electron microscopic study revealed that the compound degraded fungal cell wall leading to its lysis and may be the major target for its antifungal activity. These results indicate that presence of this compound in the hemolymph of A. mylitta provides defense against fungal infection.

A ketogenic drink improves brain energy and some measures of cognition in mild cognitive impairment.

INTRODUCTION: Unlike for glucose, uptake of the brain's main alternative fuel, ketones, remains normal in mild cognitive impairment (MCI). Ketogenic medium chain triglycerides (kMCTs) could improve cognition in MCI by providing the brain with more fuel. METHODS: Fifty-two subjects with MCI were blindly randomized to 30 g/day of kMCT or matching placebo. Brain ketone and glucose metabolism (quantified by positron emission tomography; primary outcome) and cognitive performance (secondary outcome) were assessed at baseline and 6 months later. RESULTS: Brain ketone metabolism increased by 230% for subjects on the kMCT (P < .001) whereas brain glucose uptake remained unchanged. Measures of episodic memory, language, executive function, and processing speed improved on the kMCT versus baseline. Increased brain ketone uptake was positively related to several cognitive measures. Seventy-five percent of participants completed the intervention. DISCUSSION: A dose of 30 g/day of kMCT taken for 6 months bypasses a significant part of the brain glucose deficit and improves several cognitive outcomes in MCI.

Medium-Chain Fatty Acids from Eugenia winzerlingii Leaves Causing Insect Settling Deterrent, Nematicidal, and Phytotoxic Effects.

Eugenia winzerlingii (Myrtaceae) is an endemic plant from the Yucatan peninsula. Its organic extracts and fractions from leaves have been tested on two phloem-feeding insects, Bemisia tabaci and Myzus persicae, on two plant parasitic nematodes, Meloidogyne incognita and Meloidogyne javanica, and phytotoxicity on Lolium perenne and Solanum lycopersicum. Results showed that both the hexane extract and the ethyl acetate extract, as well as the fractions, have strong antifeedant and nematicidal effects. Gas chromatography-mass spectrometry analyses of methylated active fractions revealed the presence of a mixture of fatty acids. Authentic standards of detected fatty acids and methyl and ethyl derivatives were tested on target organisms. The most active compounds were decanoic, undecanoic, and dodecanoic acids. Methyl and ethyl ester derivatives had lower effects in comparison with free fatty acids. Dose-response experiments showed that undecanoic acid was the most potent compound with EC50 values of 21 and 6 nmol/cm2 for M. persicae and B. tabaci, respectively, and 192 and 64 nmol for M. incognita and M. javanica, respectively. In a phytotoxicity assay, medium-chain fatty acids caused a decrease of 38-52% in root length and 50-60% in leaf length of L. perenne, but no effects were observed on S. lycopersicum. This study highlights the importance of the genus Eugenia as a source of bioactive metabolites for plant pest management.

Decanoic acid suppresses proliferation and invasiveness of human trophoblast cells by disrupting mitochondrial function.

Decanoic acid (DA) is a medium-chain fatty acid used in the manufacture of various products including plastics, cosmetics, and lubricants. In addition to antiviral and antibacterial effects, DA's, reported biological activities include regulation of signaling pathways and redox homeostasis in various human cell types. The influence of DA on functional properties of human trophoblasts, including proliferation, invasion and apoptosis is currently unknown. In the present study, we evaluated the anti-proliferative and anti-invasive effects of DA on the human trophoblast cell line HTR8/SVneo. In addition, DA induced oxidative stress, as evidenced by generation of reactive oxygen species (ROS) and induction of lipid peroxidation (LPO). This oxidative stress was accompanied by activation of the mitochondria-dependent apoptotic pathway in HTR8/SVneo cells. We also observed elevated mitochondrial Ca2+, and loss of mitochondrial membrane potential in response to DA treatment. Chelation of mitochondrial Ca2+ using BAPTA-AM rescued cellular proliferation suppressed by DA. We also verified that signaling proteins including AKT, P70S6K, S6, and ERK1/2 and their targets were significantly reduced in HTR8/SVneo cells by DA treatment. Pre-treatment of cells with selective inhibitors of AKT (LY294002) and ERK1/2 (U0126) revealed that the AKT and ERK1/2 signaling pathways regulated by DA displayed cross-talk in HTR8/SVneo cells. Collectively, these results suggest that personal products containing DA will have harmful effects on human trophoblasts, and could cause implantation and placentation failure during early pregnancy.

Overproduction of MCL-PHA with high 3-hydroxydecanoate Content.

Methods of producing medium-chain-length poly-3-hydroxyalkanoate (mcl-PHA) with high content of the dominant subunit, 3-hydroxydecanoate (HD), were examined with an emphasis on a high yield of polymer from decanoic acid. High HD content was achieved by using a ß-oxidation knockout mutant of Pseudomonas putida KT2440 (designated as P. putida DBA-F1) or by inhibiting ß-oxidation with addition of acrylic acid (Aa) to wild type P. putida KT2440 in carbon-limited, fed-batch fermentations. At a substrate feed ratio of decanoic acid and acetic acid to glucose (DAA:G) of 6:4 g/g, P. putida DBA-F1 accumulated significantly higher HD (97 mol%), but much lower biomass (8.5 g/L) and PHA (42% of dry biomass) than the wild type. Both biomass and PHA concentrations were improved by decreasing the ratio of DAA:G to 4:6. Moreover, when the substrate feed ratio was further decreased to 2:8, 18 g/L biomass containing 59% mcl-PHA consisting of 100 mol% HD was achieved. The yield of PHA from decanoic acid was 1.24 (g/g) indicating that de novo synthesis had contributed to production. Yeast extract and tryptone (YET) addition allowed the mutant strain to accumulate 74% mcl-PHA by weight with 97 mol% HD at a production rate of 0.41 g/L/hr, at least twice that of published data for any ß-oxidation knock-out mutant. Higher biomass concentration was achieved with Aa inhibition of ß-oxidation in the wild type but the HD content (84 mol%) was less than that of the mutant. A carbon balance showed a marked increase in supernantant organic carbon for the mutant indicating overflow metabolism. Increasing the dominant monomer content (HD) greatly increased melting point, crystallinity, and rate of crystallization.

Selective production of decanoic acid from iterative reversal of ß-oxidation pathway.

Decanoic acid is a valuable compound used as precursor for industrial chemicals, pharmaceuticals, and biofuels. Despite efforts to produce it from renewables, only limited achievements have been reported. Here, we report an engineered cell factory able to produce decanoic acid as a major product from glycerol, and abundant and renewable feedstock. We exploit the overlapping chain-length specificity of ß-oxidation reversal (r-BOX) and thioesterase enzymes to selectively generate decanoic acid. This was achieved by selecting r-BOX enzymes that support the synthesis of acyl-CoA of up to 10 carbons (thiolase BktB and enoyl-CoA reductase EgTER) and a thioesterase that exhibited high activity toward decanoyl-CoA and longer-chain acyl-CoAs (FadM). Combined chromosomal and episomal expression of r-BOX core enzymes such as enoyl-CoA reductase and thiolase (in the presence of E. coli thioesterase FadM) increased titer and yield of decanoic acid, respectively. The carbon flux toward decanoic acid was substantially increased by the use of an organic overlay, which decreased its intracellular accumulation and presumably increased its concentration gradient across cell membrane, suggesting that decanoic acid transport to the extracellular medium might be a major bottleneck. When cultivated in the presence of a n-dodecane overlay, the final engineered strain produced 2.1 g/L of decanoic acid with a yield of 0.1 g/g glycerol. Collectively, our data suggests that r-BOX can be used as a platform to selectively produce decanoic acid and its derivatives at high yield, titer and productivity.

Perampanel and decanoic acid show synergistic action against AMPA receptors and seizures.

Perampanel is an adjunctive treatment for epilepsy that works through the direct inhibition of AMPA receptors. The same molecular mechanism has recently been shown for a fatty acid, decanoic acid, prescribed in the medium chain triglyceride ketogenic diet for the treatment of patients with drug-resistant epilepsy. Because each compound has been proposed to act through a distinct AMPA receptor binding site, we predicted that perampanel and decanoic acid would act synergistically against AMPA receptors and, consequently, seizures. Here, we show a synergistic interaction between perampanel and decanoic acid in direct AMPA receptor inhibition, in an ex vivo model of seizure activity, and against seizure-induced activity in human brain slices. These data support a potential role for combination treatment using perampanel and dietary decanoic acid to provide enhanced seizure control.

Seizure control by decanoic acid through direct AMPA receptor inhibition.

The medium chain triglyceride ketogenic diet is an established treatment for drug-resistant epilepsy that increases plasma levels of decanoic acid and ketones. Recently, decanoic acid has been shown to provide seizure control in vivo, yet its mechanism of action remains unclear. Here we show that decanoic acid, but not the ketones ß-hydroxybutryate or acetone, shows antiseizure activity in two acute ex vivo rat hippocampal slice models of epileptiform activity. To search for a mechanism of decanoic acid, we show it has a strong inhibitory effect on excitatory, but not inhibitory, neurotransmission in hippocampal slices. Using heterologous expression of excitatory ionotropic glutamate receptor AMPA subunits in Xenopus oocytes, we show that this effect is through direct AMPA receptor inhibition, a target shared by a recently introduced epilepsy treatment perampanel. Decanoic acid acts as a non-competitive antagonist at therapeutically relevant concentrations, in a voltage- and subunit-dependent manner, and this is sufficient to explain its antiseizure effects. This inhibitory effect is likely to be caused by binding to sites on the M3 helix of the AMPA-GluA2 transmembrane domain; independent from the binding site of perampanel. Together our results indicate that the direct inhibition of excitatory neurotransmission by decanoic acid in the brain contributes to the anti-convulsant effect of the medium chain triglyceride ketogenic diet.

New experimental therapies for status epilepticus in preclinical development.

Starting with the established antiepileptic drug, valproic acid, we have taken a novel approach to develop new antiseizure drugs that may be effective in status epilepticus. We first identified that valproic acid has a potent effect on a biochemical pathway, the phosphoinositide pathway, in Dictyostelium discoideum, and we demonstrated that this may relate to its mechanism of action against seizures in mammalian systems. Through screening in this pathway, we have identified a large array of fatty acids and fatty acid derivatives with antiseizure potential. These were then evaluated in an in vitro mammalian system. One compound that we identified through this process is a major constituent of the ketogenic diet, strongly arguing that it may be the fatty acids that are mediating the antiseizure effect of this diet. We further tested two of the more potent compounds in an in vivo model of status epilepticus and demonstrated that they were more effective than valproic acid in treating the status epilepticus. This article is part of a Special Issue entitled "Status Epilepticus".

Proteins involved in wine aroma compounds metabolism by a Saccharomyces cerevisiae flor-velum yeast strain grown in two conditions.

A proteomic and exometabolomic study was conducted on Saccharomyces cerevisiae flor yeast strain growing under biofilm formation condition (BFC) with ethanol and glycerol as carbon sources and results were compared with those obtained under no biofilm formation condition (NBFC) containing glucose as carbon source. By using modern techniques, OFFGEL fractionator and LTQ-Orbitrap for proteome and SBSE-TD-GC-MS for metabolite analysis, we quantified 84 proteins including 33 directly involved in the metabolism of glycerol, ethanol and 17 aroma compounds. Contents in acetaldehyde, acetic acid, decanoic acid, 1,1-diethoxyethane, benzaldehyde and 2-phenethyl acetate, changed above their odor thresholds under BFC, and those of decanoic acid, ethyl octanoate, ethyl decanoate and isoamyl acetate under NBFC. Of the twenty proteins involved in the metabolism of ethanol, acetaldehyde, acetoin, 2,3-butanediol, 1,1-diethoxyethane, benzaldehyde, organic acids and ethyl esters, only Adh2p, Ald4p, Cys4p, Fas3p, Met2p and Plb1p were detected under BFC and as many Acs2p, Ald3p, Cem1p, Ilv2p, Ilv6p and Pox1p, only under NBFC. Of the eight proteins involved in glycerol metabolism, Gut2p was detected only under BFC while Pgs1p and Rhr2p were under NBFC. Finally, of the five proteins involved in the metabolism of higher alcohols, Thi3p was present under BFC, and Aro8p and Bat2p were under NBFC.

The ketogenic diet component decanoic acid increases mitochondrial citrate synthase and complex I activity in neuronal cells.

The Ketogenic diet (KD) is an effective treatment with regards to treating pharmaco-resistant epilepsy. However, there are difficulties around compliance and tolerability. Consequently, there is a need for refined/simpler formulations that could replicate the efficacy of the KD. One of the proposed hypotheses is that the KD increases cellular mitochondrial content which results in elevation of the seizure threshold. Here, we have focussed on the medium-chain triglyceride form of the diet and the observation that plasma octanoic acid (C8) and decanoic acid (C10) levels are elevated in patients on the medium-chain triglyceride KD. Using a neuronal cell line (SH-SY5Y), we demonstrated that 250-µM C10, but not C8, caused, over a 6-day period, a marked increase in the mitochondrial enzyme, citrate synthase along with complex I activity and catalase activity. Increased mitochondrial number was also indicated by electron microscopy. C10 is a reported peroxisome proliferator activator receptor γ agonist, and the use of a peroxisome proliferator activator receptor γ antagonist was shown to prevent the C10-mediated increase in mitochondrial content and catalase. C10 may mimic the mitochondrial proliferation associated with the KD and raises the possibility that formulations based on this fatty acid could replace a more complex diet. We propose that decanoic acid (C10) results in increased mitochondrial number. Our data suggest that this may occur via the activation of the PPARγ receptor and its target genes involved in mitochondrial biogenesis. This finding could be of significant benefit to epilepsy patients who are currently on a strict ketogenic diet. Evidence that C10 on its own can modulate mitochondrial number raises the possibility that a simplified and less stringent C10-based diet could be developed.