Comparative 2-DE proteomic analysis of date palm (Phoenix dactylifera L.) somatic and zygotic embryos

Two-dimensional gel electrophoresis coupled to mass spectrometry has been used to compare the proteome of date palm (Phoenix dactylifera L. cv. Deglet Nour) zygotic and somatic embryos. Proteins were trichloroacetic acid–acetone–phenol extracted, quantified, and resolved by 2-DE in the 5 to 8 pH range. Total protein content and number of resolved spots were higher in zygotic (110 ± 14.5 mg/g DW; 349 spots) than in somatic (70.96 ± 4.8 mg/g DW; 210 spots) embryos. The 2-DE map of both systems showed qualitative (263) and quantitative (72) differences. Statistical analysis of spot intensity was performed by PCA, obtaining two accurate groupings of the samples and determining the most discriminating spots. Samples were also clustered using Euclidean distance with average linkage algorithm of the Genesis software package. Sixty-three variable spots were subjected to mass spectrometry analysis, resulting in 23 identifications. Identified proteins were classified in the following functional categories; glycolysis (8 proteins), citrate cycle (1), ATP synthesis (1), carbohydrate biosynthesis (2), amino acids metabolism (1), stress related (4), storage (3), and with no function assigned for three of them. Most of the somatic embryo specific proteins identified belonged to glycolysis pathways, whereas those of the zygotic embryo to storage and stress-related proteins. Differences are discussed in terms of metabolism and biology of both types of embryos.     

Effect of (+)-usnic acid on mitochondrial functions as measured by mitochondria-specific oligonucleotide microarray in liver of B6C3F1 mice

Usnic acid is a lichen metabolite used as a weight-loss dietary supplement due to its uncoupling action on mitochondria. However, its use has been associated with severe liver disorders in some individuals. Animal studies conducted thus far evaluated the effects of usnic acid on mitochondria primarily by measuring the rate of oxygen consumption and/or ATP generation. To obtain further insight into usnic acid-mediated effects on mitochondria, we examined the expression levels of 542 genes associated with mitochondrial structure and functions in liver of B6C3F₁ female mice using a mitochondria-specific microarray. Beginning at 8 weeks of age, mice received usnic acid at 0, 60, 180, and 600 ppm in ground, irradiated 5LG6 diet for 14 days. Microarray analysis showed a significant effect of usnic acid on the expression of several genes only at the highest dose of 600 ppm. A prominent finding of the study was a significant induction of genes associated with complexes I through IV of the electron transport chain. Moreover, several genes involved in fatty acid oxidation, the Krebs cycle, apoptosis, and membrane transporters were over-expressed. Usnic acid is a lipophilic weak acid that can diffuse through mitochondrial membranes and cause a proton leak (uncoupling). The up-regulation of complexes I–IV may be a compensatory mechanism to maintain the proton gradient across the mitochondrial inner membrane. In addition, induction of fatty acid oxidation and the Krebs cycle may be an adaptive response to uncoupling of mitochondria.     

Metabolites of puerarin identified by liquid chromatography tandem mass spectrometry: Similar metabolic profiles in liver and intestine of rats

Puerarin is a major active ingredient of Pueraria Radix. Puerarin may exert its medicinal functions in part via its metabolites. In this study, we identified these metabolites to better understand and elucidate puerarin's metabolic pathway. Puerarin was intravenously administered to rats and then metabolites in plasma samples were identified by rapid resolution liquid chromatography electrospray ionization-collision induced dissociation tandem mass spectrometry (RRLC-ESI-CID–MS/MS). Chromatography was conducted on a Zorbax SB C18 column (2.1 × 100 mm, 1.8 μm) at 30 °C, with a gradient mobile phase consisting of 0.05% formic acid and acetonitrile, a flow rate of 0.2 mL min^?1, and a total run time of 14 min. MS/MS acquisition parameters were as follows: positive ionization mode, dry gas: nitrogen, 10 L min^?1, dry temperature: 350 °C, nebulizer: 40 psi, capillary: ?3500 V, scan range: 250–800. The autoMS, manual, or multiple reaction monitoring mode was selected as required. Two glucuronidated metabolites of puerarin (M1 and M2) were detected. M1 and M2 are presumed to be puerarin-7-O-glucuronide and puerarin-4′-O-glucuronide, respectively, and M2 likely is suspected to be the major metabolite because it represented the predominate peak. Kinetic studies of metabolites demonstrated that M1 and M2 were detected in rat plasma at 5 min after intravenous administration of puerarin, the levels of M1 and M2 then reached their peaks at 10–15 and 15–30 min, respectively. The metabolic profiles were similar in rat liver and intestine investigated by in situ liver and intestine perfusion, indicating that no metabolic regioselectivity of puerarin occurs in the two organs.     

Molecular ecological responses of the dinoflagellate Karenia mikimotoi to phosphate stress

Karenia mikimotoi is a toxic, widespread dinoflagellate which could produce hemolytic toxins and ichthyotoxins affecting fisheries within the area of its bloom. Previous ecophysiological studies indicated that the enhance of environmental phosphate concentration could promote the growth of K. mikimotoi. Intrinsic mechanisms regarding the effects of external phosphate on its photosynthesis, cell cycle succession and differential proteins’ expressions are still unknown. K. mikimotoi was cultured in phosphate-deprived medium, while the culture in f/2 medium (Guillard, 1975) was introduced as phosphate-sufficient control experiment. Cell counts and phosphate concentration detection were performed every other day. Flowcytometry was applied to measure cell cycle succession and chlorophyll fluorescence intensity fluctuation. Differential proteomics expression was examined by SDS-PAGE tandem LTQ Orbitrap MS/MS spectrometry. Functions of each differential protein were searched within NCBInr protein database and Swissprot database. Our study demonstrated that phosphate stress inhibited growth and cell cycle succession of K. mikimotoi remarkably (p < 0.01). Algal chlorophyll fluorescence intensity was significantly affected by phosphate deprivation (p < 0.05). 11 species of differential proteins were detected only in phosphate-limited culture sample which related to stress signal transduction, vacuolar phosphate release, phospholipid degradation, organic acid synthesis and phagotrophy. 4 kinds of differential proteins were identified only in f/2 medium culture sample which referred to cell proliferation, glycolysis, SAM cycle and polyamine production. Based on analysis of differential proteomic functional annotation, we hypothesized proteomic response mechanism of K. mikimotoi to phosphate stress. Molecular biological responses of dinoflagellate K. mikimotoi to phosphate stress was explored.     

Mammalian ALOX15 orthologs exhibit pronounced dual positional specificity with docosahexaenoic acid

Mammalian lipoxygenases (LOX) have been implicated in cell differentiation and in the pathogenesis of inflammatory, hyperproliferative and neurological diseases. Although the reaction specificity of mammalian LOX with n − 6 fatty acids (linoleic acid, arachidonic acid) has been explored in detail little information is currently available on the product patterns formed from n − 3 polyenoic fatty acids, which are of particular nutritional importance and serve as substrate for the biosynthesis of pro-resolving inflammatory mediators such as resolvins and maresins. Here we expressed the ALOX15 orthologs of eight different mammalian species as well as human ALOX12 and ALOX15B as recombinant his-tag fusion proteins and characterized their reaction specificity with the most abundantly occurring polyunsaturated fatty acids (PUFAs) including 5,8,11,14,17-eicosapentaenoic acid (EPA) and 4,7,10,13,16,19-docosahexaenoic acid (DHA). We found that the LOX isoforms tested accept these fatty acids as suitable substrates and oxygenate them with variable positional specificity to the corresponding n − 6 and n − 9 hydroperoxy derivatives. Surprisingly, human ALOX15 as well as the corresponding orthologs of chimpanzee and orangutan, which oxygenates arachidonic acid mainly to 15S-H(p)ETE, exhibit a pronounced dual reaction specificity with DHA forming similar amounts of 14- and 17-H(p)DHA. Moreover, ALOX15 orthologs prefer DHA and EPA over AA when equimolar concentrations of n − 3 and n − 6 PUFA were supplied simultaneously. Taken together, these data indicate that the reaction specificity of mammalian LOX isoforms is variable and strongly depends on the chemistry of fatty acid substrates. Most mammalian ALOX15 orthologs exhibit dual positional specificity with highly unsaturated n − 3 polyunsaturated fatty acids.     

Metabolic and cellular stress responses of catfish,Horabagrus brachysoma (Günther) acclimated to increasing temperatures

We investigated the metabolic and cellular stress responses in an endemic catfish Horabagrus brachysoma acclimated to ambient (26 °C), 31, 33 and 36 °C for 30 days. After acclimation, fish were sampled to investigate changes in the levels of blood glucose, tissue glycogen and ascorbic acid, activities of enzymes involved in glycolysis (LDH), citric acid cycle (MDH), gluconeogenesis (FBPase and G6Pase), pentose phosphate pathway (G6PDH), protein metabolism (AST and ALT), phosphate metabolism (ACP and ALP) and energy metabolism (ATPase), and HSP70 levels in various tissues. Acclimation to higher temperatures (33 and 36 °C) significantly increased activities of LDH, MDH, ALP, ACP, AST, ALT and ATPase and blood glucose levels, whereas decreased the G6PDH enzyme activity and, tissue glycogen and ascorbic acid. Results indicated an overall increase in the carbohydrate, protein and lipid metabolism implying increased metabolic demands for maintaining homeostasis in fish acclimated to higher temperatures (33 and 36 °C). We observed tissue specific response of HSP70 in H. brachysoma, with significant increase in gill and liver at 33 and 36 °C, and in brain and muscle at 36 °C, enabling cellular protection at higher acclimation temperatures. In conclusion, H. brachysoma adjusted metabolic and cellular responses to withstand increased temperatures, however, these responses suggest that the fish was under stress at 33 °C or higher temperature.     

Dietary fatty acids and oxidative stress in the heart mitochondria

Our study compared the effects of different oils on oxidative stress in rat heart mitochondria, as well as on plasma parameters used as risk factors for cardiovascular disease. The rats were fed for 16 weeks with coconut, olive, or fish oil diet (saturated, monounsaturated, or polyunsaturated fatty acids, respectively). The cardiac mitochondria from rats fed with coconut oil showed the lowest concentration of oxidized proteins and peroxidized lipids. The fish oil diet leads to the highest oxidative stress in cardiac mitochondria, an effect that could be partly prevented by the antioxidant probucol. Total and LDL cholesterols decreased in plasma of rats fed fish oil, compared to olive and coconut oils fed rats. A diet enriched in saturated fatty acids offers strong advantages for the protection against oxidative stress in heart mitochondria.     

Yokukansan,a traditional Japanese herbal medicine,alleviates the emotional abnormality induced by maladaptation to stress in mice

The aim of the present study was to examine the effect of yokukansan, a traditional Japanese herbal medicine that is composed of Atractylodis lanceae Rhizoma, Poria, Cnidii Rhizoma, Uncariae Uncis cum Ramulus, Angelicae Radix, Bupleuri Radix and Glycyrrhizae Radix, on the emotional abnormality induced by maladaptation to stress in mice. Mice were exposed to repeated restraint stress for 60 or 240 min/day for 14 days. From the 3rd day of stress exposure, mice were given yokukansan orally (p.o.) or the 5-HT_1A receptor agonist flesinoxan intraperitoneally (i.p.) immediately after the daily exposure to restraint stress. After the final exposure to restraint stress, the emotionality of mice was evaluated using an automatic hole-board apparatus. A single exposure to restraint stress for 60 min induced a decrease in head-dipping behavior in the hole-board test. This emotional stress response disappeared in mice that had been exposed to repeated restraint stress for 60 min/day for 14 days, which confirmed the development of stress adaptation. In contrast, mice that were exposed to restraint stress for 240 min/day for 14 days did not develop this stress adaptation, and still showed a decrease in head-dipping behavior. The decreased emotionality observed in stress-maladaptive mice was significantly recovered by chronic treatment with yokukansan (1000 mg/kg, p.o.) as well as flesinoxan (0.25 and 0.5 mg/kg, i.p.) immediately after daily exposure to stress. These findings suggest that yokukansan may have a beneficial effect on stress adaptation and alleviate the emotional abnormality under conditions of excessive stress.     

Effect of fasting on body composition and responses to stress in sunshine bass

The integrated responses of the hormonal regulation of growth and stress in sunshine bass (Morone chrysops X Morone saxatilis) as regulated by feed deprivation were investigated. Groups of fish were fed 1.5% of the body weight per day or offered no feed for 4 weeks. Another group of fish was not fed for 3 weeks and feed was offered during the fourth week. Fish in each group were sampled immediately before or after a 15-min low water confinement stressor after each week of the experiment. Liver mass and liver glycogen content were decreased after one week of fasting and remained low until the end of the study. However, both recovered after a week of refeeding. Intraperitoneal fat was significantly lower after two weeks of fasting and did not recover after a week of refeeding. None of these components were affected by confinement stress. Plasma glucose in unstressed fish was generally unaffected by fasting or refeeding; however, plasma glucose increased after confinement stress in fed but not in fasted fish. The cortisol stress response was unaltered by fasting and remained robust. Plasma IGF-I generally decreased in fasted fish but was not significantly lower than fed fish until the fourth week. A week of refeeding did not restore plasma IGF-I concentrations. Plasma IGF-I concentrations were higher in confinement stressed fed fish after two and four weeks but were unchanged in the fourth week. There was no change in the plasma IGF-I concentrations in fasted or refed fish due to the stress. Liver weight and liver glycogen were essentially depleted after 2 weeks of fasting. The reduction of liver glycogen greatly reduced the glucose response to stress; however, the cortisol stress response was maintained for at least four weeks of fasting. Intraperitoneal fat was decreased very little after 4 weeks of fasting. Plasma IGF-I concentrations were reduced only after 3 weeks of fasting.     

Hydroxytyrosol prevents metabolic impairment reducing hepatic inflammation and restoring duodenal integrity in a rat model of NAFLD

The potential mechanisms of action of polyphenols in nonalcoholic fatty liver disease (NAFLD) are overlooked. Here, we evaluate the beneficial therapeutic effects of hydroxytyrosol (HT), the major metabolite of the oleuropein, in a nutritional model of insulin resistance (IR) and NAFLD by high-fat diet. Young male rats were divided into three groups receiving (1) standard diet (STD; 10.5% fat), (2) high-fat diet (HFD; 58.0% fat) and (3) HFD + HT (10 mg/kg/day by gavage). After 5 weeks, the oral glucose tolerance test was performed, and at 6th week, blood sample and tissues (liver and duodenum) were collected for following determinations. The HT-treated rats showed a marked reduction in serum AST, ALT and cholesterol and improved glucose tolerance and insulin sensitivity, reducing homeostasis model assessment index. HT significantly corrected the metabolic impairment induced by HFD, increasing hepatic peroxisome proliferator-activated receptor PPAR-α and its downstream-regulated gene fibroblast growth factor 21, the phosphorylation of acetyl-CoA carboxylase and the mRNA carnitine palmitoyltransferase 1a. HT also reduced liver inflammation and nitrosative/oxidative stress decreasing the nitrosylation of proteins, reactive oxygen species production and lipid peroxidation. Moreover, HT restored intestinal barrier integrity and functions (fluorescein isothiocyanate-dextran permeability and mRNA zona occludens ZO-1). Our data demonstrate the beneficial effect of HT in the prevention of early inflammatory events responsible for the onset of IR and steatosis, reducing hepatic inflammation and nitrosative/oxidative stress and restoring glucose homeostasis and intestinal barrier integrity.     

Influence of organic systems on milk fatty acid profile and CLA in goats

The effect of organic system on the fatty acid profile of milk and CLA content was evaluated using 30 pregnant pluriparous goats, divided into two homogeneous groups (S and O) of 15 goats each. Group S was housed in a stable and received alfalfa hay as forage, while group O was raised according EC Regulation 834/2007 and led to pasture. After the kids weaning, goats were milked twice a day for 5 months. Daily milk yield was recorded and, monthly, representative milk samples from the two daily milkings were analysed for chemical and fatty acid profile. Average milk yield did not differ statistically between the groups. The goats of the O group had significantly higher fat content in milk than those of group S (65.9 g/day vs. 54.3 g/day, P < 0.01). Among milk fatty acids, organic system significantly affected the percentages of C18:1 c9, C18:1 t11, linoleic acid, alpha-linolenic acid, monounsaturated fatty acid and polyunsaturated fatty acid. Organic system highly influenced the c9 t11 conjugated linoleic acid (CLA) (0.810 g/100 g of fat vs. 0.542 g/100 g of fat, for groups O and S, respectively, P < 0.01), t10 c12 CLA (0.041 g/100 g of fat vs. 0.024 g/100 g of fat, for groups O and S, respectively, P < 0.01) and ∑CLA (0.87 g/100 g of fat vs. 0.58 g/100 g of fat for groups O and S, respectively, P < 0.01) concentrations of milk.     

Xanthohumol lowers body weight and fasting plasma glucose in obese male Zucker fa/fa rats

Obesity contributes to increased risk for several chronic diseases including cardiovascular disease and type 2 diabetes. Xanthohumol, a prenylated flavonoid from hops (Humulus lupulus), was tested for efficacy on biomarkers of metabolic syndrome in 4 week old Zucker fa/fa rats, a rodent model of obesity. Rats received daily oral doses of xanthohumol at 0, 1.86, 5.64, and 16.9 mg/kg BW for 6 weeks. All rats were maintained on a high fat (60% kcal) AIN-93G diet for 3 weeks to induce severe obesity followed by a normal AIN-93G (15% kcal fat) diet for the last 3 weeks of the study. Weekly food intake and body weight were recorded. Plasma cholesterol, glucose, insulin, triglyceride, and monocyte chemoattractant protein-1 (MCP-1) levels were assessed using commercial assay kits. Plasma and liver tissue levels of XN and its metabolites were determined by liquid–chromatography tandem mass spectrometry. Plasma and liver tissue levels of xanthohumol were similar between low and medium dose groups and significantly (p < 0.05) elevated in the highest dose group. There was a dose-dependent effect on body weight and plasma glucose levels. The highest dose group (n = 6) had significantly lower plasma glucose levels compared to the control group (n = 6) in male but not female rats. There was also a significant decrease in body weight for male rats in the highest dose group (16.9 mg/kg BW) compared to rats that received no xanthohumol, which was also not seen for female rats. Plasma cholesterol, insulin, triglycerides, and MCP-1 as well as food intake were not affected by treatment. The findings suggest that xanthohumol has beneficial effects on markers of metabolic syndrome.     

Potential chemoprevention of diethylnitrosamine-initiated and 2-acetylaminofluorene-promoted hepatocarcinogenesis by zerumbone from the rhizomes of the subtropical ginger (Zingiber zerumbet)

Zerumbone (ZER), a monosesquiterpene found in the subtropical ginger (Zingiber zerumbet Smith), possesses antiproliferative properties to several cancer cells lines, including the cervical, skin and colon cancers. In this study, the antitumourigenic effects of ZER were assessed in rats induced to develop liver cancer with a single intraperitoneal injection of diethylnitrosamine (DEN, 200 mg/kg) and dietary 2-acetylaminofluorene (AAF) (0.02%). The rats also received intraperitoneal ZER injections at 15, 30 or 60 mg/kg body wt. twice a week for 11 weeks, beginning week four post-DEN injection. The hepatocytes of positive control (DEN/AAF) rats were smaller with larger hyperchromatic nuclei than normal, showing cytoplasmic granulation and intracytoplasmic violaceous material, which were characteristics of hepatocarcinogenesis. Histopathological evaluations showed that ZER protects the rat liver from the carcinogenic effects of DEN and AAF. Serum alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (AP) and alpha-fetoprotein (AFP) were significantly lower (P < 0.05) in ZER-treated than untreated rats with liver cancer. The liver malondialdehyde (MDA) concentrations significantly (P < 0.05) increased in the untreated DEN/AAF rats indicating hepatic lipid peroxidation. There was also significant (P < 0.05) reduction in the hepatic tissue glutathione (GSH) concentrations. The liver sections of untreated DEN/AAF rats also showed abundant proliferating cell nuclear antigen (PCNA), while in ZER-treated rats the expression of this antigen was significantly (P < 0.05) lowered. By the TUNEL assay, there were significantly (P < 0.05) higher numbers of apoptotic cells in DEN/AAF rats treated with ZER than those untreated. Zerumbone treatment had also increased Bax and decreased Bcl-2 protein expression in the livers of DEN/AAF rats, which suggested increased apoptosis. Even after 11 weeks of ZER treatment, there was no evidence of abnormality in the liver of normal rats. This study suggests that ZER reduces oxidative stress, inhibits proliferation, induces mitochondria-regulated apoptosis, thus minimising DEN/AAF-induced carcinogenesis in rat liver. Therefore, ZER has great potential in the treatment of liver cancers.     

Free fatty acid receptor 1 (GPR40) agonists containing spirocyclic periphery inspired by LY2881835

The free fatty acid receptor 1 (FFA1), a G protein-coupled receptor (GPCR) naturally activated by long-chain fatty acids is a novel target for the treatment of metabolic diseases. The basic amine spirocyclic periphery of Eli Lilly’s drug candidate LY2881835 for treatment of type 2 diabetes mellitus (which reached phase I clinical trials) inspired a series of novel FFA1 agonists. These were designed to incorporate the 3-[4-(benzyloxy)phenyl]propanoic acid pharmacophore core decorated with a range of spirocyclic motifs. The latter were prepared via the Prins cyclization and subsequent modification of the 4-hydroxytetrahydropyran moiety in the Prins product. Here, we synthesize 19 compounds and test for FFA1 activity. Within this pilot set, a nanomolar potency (EC₅₀ = 55 nM) was reached. Four lead compounds (EC₅₀ range 55–410 nM) were characterized for aqueous solubility, metabolic stability, plasma protein binding and Caco-2 permeability. While some instability in the presence of mouse liver microsomes was noted, mouse pharmacokinetic profile of the compound having the best overall ADME properties was evaluated to reveal acceptable bioavailability (F = 10.3%) and plasma levels achieved on oral administration.     

Fatty acid and nutritive quality of chia (Salvia hispanica L.) seeds and plant during growth

The fatty acid (FA) profile, chemical composition, gross energy and organic matter digestibility of chia (Salvia hispanica L.) have been determined in the seed and in the plant collected at five progressive morphological stages from early vegetative to budding stage. The FA analyses disclosed quantitative differences between the plant stages that were characterised by a high percentage of polyunsaturated fatty acids (PUFA), which made up from 752 to 623 g/kg of the total FA of the plant during the growth cycle. The α-linolenic acid (ALA, C_18:3n–3) decreased from 649 g/kg, at the early vegetative stage, to 499 g/kg of the total FA, at the budding stage, while all the other FAs increased with increasing growth stage. The chia seed FAs were also highly unsaturated, with their main components being ALA (641 g/kg of the total FA) and linoleic acid (LA, C_18:2n–6; 188 g/kg of the total FA).The evolution of the quality of chia is closely related to the ageing of the plant. The chia plant provides a forage with a good nutritive value when harvested at a stage before the shooting period. After this, the nutritional quality of the plant considerably decreases with an increase in the fibrous fractions and a dramatical decrease of the crude protein content.     

Suppression of VLDL secretion by cultured hepatocytes incubated with chylomicron remnants enriched in n−3 polyunsaturated fatty acids is regulated by hepatic nuclear factor-4α

Dietary n? 3 polyunsaturated fatty acids (PUFA) suppress the secretion of very low density lipoprotein (VLDL) directly when delivered to the liver in chylomicron remnants (CMR). The role of sterol regulatory element-binding proteins (SREBPs) and hepatic nuclear factor-4α (HNF-4α) in the regulation of this effect was investigated. Chylomicron remnant-like particles (CRLPs) containing triacylglycerol (TG) from palm (rich in saturated fatty acids (SFA)) or fish (rich in n? 3 PUFA) oil were incubated with cultured rat hepatocytes (24 h) and the expression of protein and mRNA for SREBP-1, SREBP-2 and HNF-4α, and levels of mRNA for their target genes were determined. SREBP-1 and -2 protein expression in the membrane and nuclear fractions was unaffected by either type of CRLPs. mRNA abundance for SREBP-1c and -2 was also unchanged by CRLP-treatment, as were levels of mRNA for target genes of SREBP-1, including steroyl CoA desaturase, acetyl CoA carboxylase, fatty acid synthase and ATP citrate lyase, and SREBP-2 (3-hydroxy-3-methylglutaryl CoA reductase). In contrast, HNF-4α protein and mRNA levels were significantly decreased by CRLPs enriched in n? 3 PUFA, but not SFA, and the expression of mRNA for HNF-4α target genes, including HNF-1α, apolipoprotein B and the microsomal TG transfer protein, was also lowered by n? 3 PUFA-, but not SFA-enriched CRLPs. These findings suggest that the direct suppression of VLDL secretion by dietary n? 3 PUFA delivered to the liver in CMR is mediated via decreased expression of HNF-4α.     

Macamides and their synthetic analogs: Evaluation of in vitro FAAH inhibition

Maca (Lepidium meyenii), a traditional food crop of the Peruvian Andes is now widely touted as a dietary supplement. Among the various chemical constituents isolated from the plant are a unique series of non-polar, long-chain fatty acid N-benzylamides known as macamides. We have synthesized 11 of the 19 reported macamides and have tested each as potential inhibitors of the human enzyme, fatty acid amide hydrolase (FAAH). The five most potent macamides were FAAH inhibitors (IC₅₀ = 10–17 μM). These amides were derivatives of oleic, linoleic and linolenic acids and benzylamine or 3-methoxybenzylamine. Of the three compounds evaluated in a pre-incubation time study, two macamides were not irreversible inhibitors of FAAH. The third, a carbamate structurally related to macamides, was shown to be an irreversible inhibitor of FAAH (IC₅₀ = 0.153 μM).     

The influence of feeding and fasting on plasma metabolites in the dogfish shark (Squalus acanthias)

Dogfish sharks are opportunistic predators, eating large meals at irregular intervals. Here we present a synthesis of data from several previous studies on responses in plasma metabolites after natural feeding and during prolonged fasting (up to 56 days), together with new data on changes in plasma concentrations of amino acids and non-esterified fatty acids. Post-prandial and long-term fasting responses were compared to control sharks fasted for 7 days, a typical inter-meal interval. A feeding frenzy was created in which dogfish were allowed to feed naturally on dead teleosts at two consumed ration levels, 2.6% and 5.5% of body weight. Most responses were more pronounced at the higher ration level. These included increases in urea and TMAO concentrations at 20 h, followed by stability through to 56 days of fasting. Ammonia levels were low and exhibited little short-term response to feeding, but declined to very low values during the extended fast. Glucose and β-hydroxybutyrate both fell after feeding, the latter to a greater and more prolonged extent (up to 60 h), whereas acetoacetate did not change. During prolonged fasting, glucose concentrations were well regulated, but β-hydroxybutyrate increased to 2–3-fold control levels. Total plasma amino acid concentrations increased in a biphasic fashion, with peaks at 6–20 h, and 48–60 h after the meal, followed by homeostasis during the extended fast. Essential and non-essential amino acids generally followed this same pattern, though some exhibited different trends after feeding: taurine, β-alanine, and glycine (decreases or stability), alanine and glutamine (modest prolonged increases), and threonine, serine, asparagine, and valine (much larger short-term increases). Plasma non-esterified fatty acid concentrations declined markedly through 48 h after the 2.6% meal. These data are interpreted in light of companion studies showing elevations in aerobic metabolic rate, urea production, rectal gland function, metabolic base excretion, and activation of ornithine–urea cycle and aerobic enzymes after the meal, and muscle N-depletion but maintenance of osmolality and urea production during long-term fasting.