Tumor necrosis factor α attenuates glutamine-enhanced skeletal muscle protein synthesis in rats

Glutamine has been widely used in critical illness, surgery, and injury. Previous studies showed that the use of glutamine in nutritional regimens for patients with sepsis was not as effective as in patients of trauma, especially in the early stage of sepsis. The objective of this study was to determine whether the regulation of glutamine on protein synthesis in skeletal muscle could be inhibited by tumor necrosis factor α (TNF-α), one of the major mediators in sepsis in a rat model. Thirty male Sprague-Dawley rats were randomly assigned into 3 groups: total parenteral nutrition (TPN; control), Gln (treated with glutamine), and TNF-α (treated with glutamine and TNF-α). All rats received isonitrogenous and isoenergetic TPN solutions for 3 days. The control group was supplemented with TPN, the glutamine group was given glutamine-enriched TPN, and the TNF-α group was supplemented with glutamine-enriched TPN followed by intravenously infused TNF-α in the last 24 hours. In the last 30 minutes, all rats were mainlined with [l-¹⁵N]leucine. The concentrations of TNF-α and glutamine in plasma and skeletal muscle were measured, and the fractional synthesis rate was assessed. The level of TNF-α in the TNF-α group was the highest among the 3 groups. The glutamine concentration was elevated more in the TNF-α group than in the other 2 groups (P < .05). The fractional synthesis rate increased significantly in the TNF-α and Gln groups than that in the control group, and it was the highest in the Gln group (P < .05). In conclusion, TNF-α could attenuate protein synthesis in the skeletal muscle stimulated by glutamine in the early stage of sepsis in rats.     

Protein-induced alterations in murine hepatic α-aminoadipate δ-semialdehyde synthase activity are mediated posttranslationally

The molecular mechanisms responsible for alterations in lysine α-ketoglutarate reductase (LKR) activity are unknown. Therefore, the aim of these studies was to discern the mechanism(s) responsible for induction of hepatic LKR activity in rodents fed excess dietary protein. Four studies were conducted that used 84 mice. Mice were fed either a high-protein (50% casein) or adequate-protein (20% casein) diet in powder form in study 1 and a high-protein (46% casein) or adequate-protein (21% casein) diet in pellet form in the remaining studies. No significant differences in weight gain between the mice fed the different diets were detected. As expected, mice fed high-protein diets had a greater (P < .05) LKR activity in all 4 experiments. Mice fed high- and adequate-protein diets for 8 days showed no difference (P > .1) in α-aminoadipate δ-semialdehyde synthase (AASS) mRNA in experiment 1. However, after pooling the data from the remaining 3 experiments, mice receiving the high-protein diet had greater (P < .05) AASS mRNA compared to mice fed the adequate protein diet. In this investigation, no differences (P > .1) in AASS protein abundance were detected. The results are consistent with a mechanism in which posttranslational regulation is responsible for hepatic induction of LKR activity in mice fed high-protein diets.     

High-molecular-weight barley β-glucan in chapatis (unleavened Indian flatbread) lowers glycemic index

Food products incorporated with soluble dietary fiber β-glucan have shown varying effects on postprandial glycemia. The objective of the present study was to test the hypothesis that a food product fortified with barley β-glucan and subjected to minimum processing and mild cooking might be effective in lowering glycemic response. In a randomized, single-blind, controlled crossover trial, 8 healthy human subjects (3 men, 5 women; aged 26-50 years; body mass index, <30 kg/m²) consumed unleavened Indian flatbreads called chapatis containing high-molecular-weight barley β-glucan at doses of 0, 2, 4, 6, and 8 g on different occasions. Capillary blood samples were collected at 0, 15, 30, 45, 60, 90, and 120 minutes after consuming the chapatis. The incremental area under the glucose curve values for all the 5 different types of chapatis were significantly low (P < .001) compared with reference food glucose. The incremental area under the glucose curve of chapatis containing 4 and 8 g β-glucan were significantly lower than control chapatis (P < .05). Postprandial blood glucose was significantly reduced at 45 minutes by chapatis containing 4 g (P < .05) and 8 g β-glucan (P < .01) and at 60 minutes by chapatis with 8 g β-glucan (P < .01). The glycemic index (GI) values of chapatis with 4 and 8 g β-glucan were 43% to 47% lower (GI, 30 and 29, respectively) compared with chapatis without β-glucan (GI, 54). We conclude that barley β-glucan significantly reduces GI of chapatis, particularly at doses of 4 and 8 g per serving.     

Effect of 1,4-dioxanyl substitution on the adrenergic activity of some standard α-adrenoreceptor agents

A preliminary communication reported on the pharmacology of the potent partial α₂-agonist (2-(1,4-benzodioxan-6-ylamino)-2-imidazoline, a 1,4-dioxan derivative of clonidine. Its degree of agonism/antagonism depended upon the peripheral or central α₂-adrenoreceptor system studied. It was of interest to discover whether a similar substitution of the 1,4-dioxan moiety in other standard α-adrenergic agents would similarly produce high affinity compounds of complex pharmacological profile. The same substitution when introduced into guanfacine, fenmetazole and tolazoline resulted in unpredictable changes in profile with a reduction in α-affinity.     

Research of potential antidepressant drugs with α2-adrenoreceptor antagonist and NA-uptake inhibiting properties: synthesis of 2-(1-hydroxy-2-phenoxy-2-phenyl)ethyl-4,5-dihydro-1H-imidazole derivatives

A series of 2-(1-hydroxy-2-phenoxy-2-phenyl)ethyl-4,5-dihydro-1H-imidazole derivatives has been synthesized with the aim of finding potential antidepressant drugs endowed with both NA-uptake and α₂-antagonist properties. The structure of the new compounds was designed by mixing the common elements present in reboxetine and α-aryloxy-benzyl derivatives of ethanolamine, both having NA-uptake inhibitory properties in vitro, and in idazoxan, a potent and selective α₂-adrenoreceptor antagonist. The new hybrids allow a good fitting of the common features without the strong steric interactions occurring when the structure of reboxetine is superimposed on that of idazoxan. However, the new derivatives did not display significant interaction with the NA-uptake system and the α₂-adrenoreceptors and proved inactive in the antireserpine test taken as a model of potential antidepressant activity. The possible relationship between the structural changes made in the parent molecules and the complete loss of activity on both systems is discussed.     

α-Tocopherol, fatty acids and their correlations in Bulgarian foodstuffs

HPLC and GC methods were used for the analysis of 33 foodstuffs divided into 7 groups: cereals, oils and fats, milk and dairy products, meat, eggs and poultry, fish and nuts. The richest sources of α-tocopherol (α-T), seed oils, show considerable variations of α-T (11.0 mg% soybean oil–44.88 mg% sunflower seed oil), as does the content of PUFA (12.72 g% olive oil–66.87 g% sunflower seed oil) with approximately the same content of total lipids (TL) (99.79–99.89 g%). A correlation was established between α-T and total lipids r=0.61 (T=4.28, P>99%). An even higher correlation was found between α-T and polyunsaturated fatty acids r=0.80 (T=7.42, P>99%). Regarding the essential n-6 and n-3 fatty acids α-T was established to correlate only with n-6 fatty acids r=0.82 (T=7.50, P>99%).     

Effect of Storage on Organoleptic Characteristics and Nutritional Evaluation of β -Carotene and Iron-Rich Products

Vitamin A deficiency and iron deficiency anaemia are two major micronutritional disorders of national importance affecting the vulnerable groups of the population. In the present study an effort has been made to combat this problem by developing β -carotene and iron-rich products, namely biscuits and shakarpara by adding cauliflower leaves powder and these were stored to see the effect of storage on their organoleptic and nutritional evaluation. Fresh biscuits and shakarpara were found organoleptically acceptable, whereas the mean scores of organoleptic characteristics decreased gradually after 60 days of storage. Moisture, protein, fat, crude fibre, minerals, carbohydrates and energy contents were 2.98 g, 8.49 g, 20.90 g, 0.90 g, 1.38 g, 65.35 g and 2025 kJ/100 g in biscuits and 6.22 g, 5.38 g, 23.80 g, 0.42 g, 1.08 g, 63.10 g and 2042 kJ/100 g in shakarpara, on fresh weight basis, respectively. β -Carotene content was 1.42 mg/100 g in biscuits and 1.55 mg/100 g in shakarpara, which decreased significantly after 60 days of storage. Total iron content was 7.16 mg/100 g in biscuits and 8.44 mg/100 g in shakarpara. Soluble iron, ionizable iron andin vitro iron at pH 7.50 in biscuits were 2.84 mg/100 g, 1.25 mg/100 g and 8.70% of total iron and inshakarpara 9.96 mg/100g, 1.75 mg/100 g and 10.24% of total iron, respectively, which decreased significantly after 60 days of storage in both products. These products can be stored for up to 30 days without any significant change in organoleptic and nutritional characteristics.     

Differential Effects of Short-Chain Fatty Acids on L6 Myotube Inflammatory Mediator Production in Response to Lipopolysaccharide- or Palmitic Acid-Stimulation

Short-chain fatty acids (SCFA) produced from dietary non-digestible carbohydrate fermentation have metabolic effects in skeletal muscle; however, their effect on inflammatory mediator production is unknown. In this study, L6 myotubes were cultured with individual SCFA (acetate, propionate, and butyrate) at 0.5 mM and 2.5 mM ± 10 ng/mL lipopolysaccharide (LPS) or ± 500 µM palmitic acid (PA) for 24 h. In response to LPS, only butyrate had an effect at the lower concentration (0.5 mM), whereas at the higher concentration (2.5 mM) both propionate and butyrate reduced MCP-1, MIP-1α, and RANTES secretion (p < 0.05), and only butyrate reduced IL-6 secretion and intracellular protein levels of phospho-STAT3 (p < 0.05). In response to PA, 0.5 mM butyrate reduced protein expression of phospho-NFκB p65 and the secretion of IL-6, MIP-1α, and MCP-1, whereas all three SCFA reduced RANTES secretion (p < 0.05). At the 2.5 mM SCFA concentration combined with PA stimulation, all three SCFA reduced intracellular protein expression of phospho-NFκB p65 and phospho-STAT3 and secreted protein levels of MCP-1, IL-6, and RANTES, whereas only butyrate reduced secretion of MIP-1α (p < 0.05). Thus, SCFA exhibit differential effects on inflammatory mediator expression in response to LPS and PA stimulation, which has implications for their individual impacts on inflammation-mediated skeletal muscle dysfunction.     

Prostaglandin E2 production in mice is reduced by consumption of range-fed sources of red meat

Many view bison as a healthful alternative to other red meat sources, and as a way to decrease health risks, they associate it with meat consumption. Using mice as a model for immune function, we hypothesized that consumption of meat from range-fed bison would decrease prostaglandin (PG) E₂ and alter prostacyclin (PGI₂) release upon immune challenge when compared with mice fed meat from grain-finished bison, range-fed beef, feedlot steers, free-ranging elk, or chicken breast. After 2 weeks on an experimental diet and inflammatory stimulation, mouse peritoneal macrophage was isolated and analyzed in 12 animals per diet. Peritoneal cell arachidonic acid increased in response to a chicken-based diet (P < .05), which was likely attributable to higher arachidonic acid intake. Release of PGE₂ was lowest in mice consuming meat of range-fed beef, range-fed bison, and elk but was highest with meat of grain-finished beef and intermediate in mice fed chicken (P < .05). Mice fed elk meat had the greatest PGI₂, whereas PGI₂ was decreased in mice fed meat of either range bison, range beef, or chicken (P < .05) and intermediate in mice fed meat of steers or bison finished in a feedlot. We conclude that consumption of meats characteristic of range-fed ruminants or wild ungulates supports reduced PGE₂ and greater PGI₂ synthesis, indicating potentially greater immune health and lower blood clotting potential than meat from grain-finished cattle or bison in this model system.     

A new method for the determination of vitamin D3 and 25-hydroxyvitamin D3 in meat

The total vitamin D content in meat, i.e., vitamin D₃ and 25-hydroxyvitamin D₃, was determined by HPLC after alkaline hydrolysation, solid-phase extraction and semi-preparative HPLC. For detection, a DAD detector between 220 and 320 nm was used and quantification was performed at 265 nm. Vitamin D₂ was used as internal standard for vitamin D₃ as well as for 25-hydroxyvitamin D₃. Precision for vitamin D₃ was determined in lean meat and lard to 9.1% and 7.1%, respectively. The corresponding values for 25-hydroxyvitamin D₃ were 8.9% and 9.9%. Accuracy was determined in spiked samples, which showed a recovery of 94.7% and 99.0% for vitamin D₃ and 25-hydroxyvitamin D₃, respectively. The method is applicable for establishing data for food composition tables.     

The effect of long-term supplementation with different dietary ω-6/ω-3 ratios on mineral content and ex vivo prostaglandin E2 release in bone of growing rabbits

BACKGROUND/OBJECTIVES

The aim of this research was to study the different long term effects of consumption of dietary oil sources with varying omega-6/omega-3 (ω-6/ω-3) polyunsaturated fatty acids (PUFAs) ratios on bone marrow fatty acid level, ex vivo prostaglandin E₂ (PGE₂) release, and mineral content of bone in rabbits.

MATERIALS/METHODS

For this purpose, weaning and female New Zealand white rabbits were purchased and randomly divided into five groups and offered ad libitum diets containing 70 g/kg of added oil for 100 days. The dietary lipid treatments were formulated to provide the following ratios of ω-6/ω-3 fatty acids: 8.68 soy bean oil (SBO control), 21.75 sesame oil (SO), 0.39 fish oil (FO), 0.63 algae oil (DHA), and 0.68 algae oils (DHA/ARA). DHA and ARA are two types of marine microalgae of the genus Crypthecodinium cohnii.

RESULTS

The dietary treatments had significant effects on the bone marrow fatty acids of rabbits. Rabbits fed the FO diet, containing the highest ω-3 PUFA concentration, and those fed the SBO diet showed the highest ω-6 PUFA. On the other hand, a positive correlation was observed between Ex vivo PGE₂ level and the ω-6/ω-3 dietary ratio. Significant effects of dietary treatment on femur Ca, P, Mg, and Zn contents were observed in both genders.

CONCLUSIONS

Findings of the current study clearly demonstrated that dietary PUFA, particularly ω-6/ω-3 and ARA/EPA ratios are important factors in determining bone marrow fatty acid profile, and this in turn determines the capacity of bone for synthesis of PGE₂, thereby reducing bone resorption and improving bone mass during growth.     

Design and one-pot synthesis of α-aminophosphonates and bis(α-aminophosphonates) by iron(III) chloride and cytotoxic activity

In this study, we used a solution of FeCl₃ in THF to facilitate the Mannich-type reaction of aldehyde, amine and phosphite compounds to form corresponding α-aminophosphonates in a one-pot, three-component reaction. Selected α-aminophosphonates were entered into a biological assay test and were studied by docking methods, using Autodock 3.0.The results showed that the reactions were carried out mildly and eco-friendly to form α-aminophosphonates in high yields. Some were found to have cytotoxic activity on the cell lines RAJI, JURKAT and MCF-7. An indole derived bis(α-aminophosphonates) showed maximum cytotoxic effect comparable to doxorubicin. Although the FDE (Final Docking Energy) for the most cytotoxic compound was of the most negative value, there is no correlation between FDE and cytotoxicity.     

Diamine-based human histamine H3 receptor antagonists: (4-Aminobutyn-1-yl)benzylamines

A series of (4-aminobutyn-1-yl)benzylamines were prepared and the SAR around three key areas: (1) the amine attached to the butynyl linker (R³R⁴N–); (2) the benzylamine moiety (R¹R²N–); and (3) the point of attachment of the benzylamine group (R¹R²N– in the ortho, meta, or para positions) was examined. One compound, 4-[3-(4-piperidin-1-yl-but-1-ynyl)-benzyl]-morpholine (9s) was chosen for further profiling and found to be a selective histamine H₃ antagonist with desirable drug-like properties. Ex vivo receptor occupancy studies established that 9s does occupy H₃ binding sites in the brain of rats after oral administration. Subcutaneous doses of 9s (10 mg/kg) given during the natural sleep phase demonstrated robust wake-promoting effects.     

Synthesis, structure and structure–activity relationship analysis of 3-tert-butoxycarbonyl-2-arylthiazolidine-4-carboxylic acid derivatives as potential antibacterial agents

Nine 2-arylthiazolidine-4-carboxylic acid derivatives and nine 3-tert-butoxycarbonyl-2-arylthiazolidine-4-carboxylic acid derivatives were synthesized to screen for their antibacterial activities. Compounds 5, 14–18 were first reported. Their chemical structures were clearly determined by ¹H NMR, ¹³C NMR, ESI mass spectra and elemental analyses, coupled with one selected single-crystal structure. All the compounds were assayed for antibacterial activities against two Gram-positive bacterial strains (Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 6538) and two Gram-negative bacterial strains (Escherichia coli ATCC 35218 and Pseudomonas aeruginosa ATCC 13525) by MTT method. Most of the 3-tert-butoxycarbonyl-2-arylthiazolidine-4-carboxylic acid derivatives exhibited better antibacterial activities against the four bacterial strains than relative 2-arylthiazolidine-4-carboxylic acid derivatives. Compound (2RS,4R)-3-(tert-butoxycarbonyl)-2-(5-fluoro-2-hydroxyphenyl)thiazolidine-4-carboxylic acid (14) showed powerful antibacterial activities against P. aeruginosa with IC₅₀ value of 0.195 μg/mL, which was superior to the positive controls Penicillin G and Kanamycin B, respectively. On the basis of the biological results, structure–activity relationships were discussed.     

Synthesis and pharmacological properties of novel benzamide derivatives acting as ligands to the 5-hydroxytryptamine 4 (5-HT4) receptor

Aseries of 4-amino-5-chloro-2-methoxy-N-(1-substituted piperidin-4-ylmethyl)benzamides was synthesized as novel gastroprokinetic agents. The affinity of these compounds for the 5-hydroxytryptamine 4 (5-HT₄) receptor was evaluated. Among these compounds, 4-amino-5-chloro-2-methoxy-N-[1-[5-(1-methylindol-3-ylcarbonylamino)pentyl]piperidin-4-ylmethyl]benzamide (3f, Y-34959) showed a higher affinity for the 5-HT₄ receptor (Ki = 0.30 nmol/L) than for other receptors, and was confirmed to be a potent 5-HT₄ receptor agonist having contractile effects in the isolated guinea-pig ascending colon (EC₅₀ = 1.2 nmol/L). In dogs, compound 3f increased gastroprokinetic motility of both the gastric antrum and the ascending colon. In addition, this effect on the colon was inhibited by azasetron, a selective 5-HT₃ receptor antagonist, demonstrating that the effect of gastroprokinetic agents having 5-HT₃ receptor antagonism on the colon were reduced compared with that of selective 5-HT₄ receptor agonists.     

α1- and α2-containing GABAA receptor modulation is not necessary for benzodiazepine-induced hyperphagia

Benzodiazepines increase food intake, an effect attributed to their ability to enhance palatability. We investigated which GABA_A receptor subtypes may be involved in mediating benzodiazepine-induced hyperphagia. The role of the α2 subtype was investigated by observing the effects of midazolam, on the behavioural satiety sequence in mice with targeted deletion of the α2 gene (α2 knockout). Midazolam (0.125, 0.25 and 0.5 mg/kg) increased food intake and the amount of time spent feeding in α2 knockout mice, suggesting that BZ-induced hyperphagia does not involve α2-containing GABA_A receptors. We further investigated the roles of α1- and α3-containing GABA_A receptors in mediating BZ-induced hyperphagia. We treated α2(H101R) mice, in which α2-containing receptors are rendered benzodiazepine insensitive, with L-838417, a compound which acts as a partial agonist at α2-, α3- and α5-receptors but is inactive at α1-containing receptors. L-838417 (10 and 30 mg/kg) increased food intake and the time spent feeding in both wildtype and α2(H101R) mice, demonstrating that benzodiazepine-induced hyperphagia does not require α1- and α2-containing GABA_A receptors. These observations, together with evidence against the involvement of α5-containing GABA_A receptors, suggest that α3-containing receptors mediate BZ-induced hyperphagia in the mouse.     

Physical, structural, and functional properties of the β1 integrin-like fibronectin receptor (β1EhFNR) in Entamoeba histolytica

The presence in Entamoeba histolytica of a fibronectin (FN) receptor, which is antigenically related to β1 integrin-like molecules and shows 99% homology with the intermediate subunit-2 of the Gal/GalNAc-specific lectin has been described. The E. histolytica genome has been sequenced, and its analysis shows no integrin sequences. Here we provide further evidence to demonstrate that this molecule behaves as integrin-like in its physical, structural and functional properties. The purified β1EhFNR complex is resolved into three polypeptides of 150, 140, and 130 kDa. Transmission electron microscopy showed individual complexes consisting of oblong heads of 3 nm × 4 nm and two projecting arms 6–7 nm in length. In the absence of detergent, these complexes formed aggregates that were composed of clusters or “rosettes” of between two and six or more β1EhFNR complexes. The physical properties of the purified β1EhFNR complexes were: R_S = 5.8 nm, S₂₀W = 8.3, f/f₀ = 1.4. This complex was seen in close physical association with adhesion plates and phagocytic invaginations, using confocal microscopy and the 3C10 mAb that recognizes these three subunits complex. Regulation of its surface expression is not dependent on protein synthesis; rather it is regulated by inward and outward mobilization of the molecules. The presence and antigenic similarity of putative β1EhFNRs in different strains and species of Entamoeba was analyzed using the 3C10 mAb; this mAb recognized the complex in all E. histolytica species, however there was no recognition in E. dispar, E. invadens, and Laredo strains. Finally, evidence is provided about post-translational modifications such as tyrosine phosphorylation and glycosylation suffered by the β1EhFNR complex.     

Determination of vitamin D3 and 25-hydroxyvitamin D3 in foodstuffs by HPLC UV-DAD and LC–MS/MS

In order to generate new data for vitamin D content for the Canadian Nutrient File, a method for the quantification of vitamin D₃ and 25(OH)D₃ in foodstuffs has been modified and improved. Vitamin D₃ was quantified using reverse phase liquid chromatography (LC) with UV-diode array detector (UV-DAD), while 25(OH)D₃ was measured by triple quadrupole mass spectrometry (APCI MS/MS). Quantification was by internal standards (IS) using vitamin D₂ and 25(OH)D₂. A Certified Reference Material (CRM-421 containing vitamin D₃) and a control sample (internally generated reference material of ground pork containing both vitamin D₃ and 25(OH)D₃) were used as validation and quality control tools. Limit of detection for both compounds was 0.04 μg/100 g. Accuracy for vitamin D in the CRM-421 was 99% (0.142 mg/kg for a target of 0.143, n = 10). Recovery of vitamin D₃ in ground pork was 97% (88% absolute recovery). For 25(OH)D₃, a recovery of 94% (73% absolute recovery) was obtained. Using this method, data for vitamin D₃ and 25(OH)D₃ content in a variety of foods (pork, beef, eggs, poultry, fish, and dinners) have been generated.     

Novel N-(3-carboxyl-9-benzyl-β-carboline-1-yl)ethylamino acids: Synthesis, anti-tumor evaluation, intercalating determination, 3D QSAR analysis and docking investigation

Sixteen novel N-(3-carboxyl-9-benzyl-β-carboline-1-yl)ethylamino acids (6a–p) were synthesized as intercalating lead compounds. In the in vitro cytotoxic assay their IC₅₀ values against five human carcinoma cell lines ranged from 10.95 μM to about 400 μM. On S180 mouse model eight of them exhibited anti-tumor action, four of them showed the same anti-tumor potency as that of cytarabine. The preliminary toxicity evaluation revealed that the LD₅₀ values of 6a–p should be more than 500 mg/kg. With CT DNA as model system an intercalating mechanism was explored. Using 3D QSAR analysis the relationship of the in vivo anti-tumor activity and the structure was quantitatively described. By docking 6a–p onto d(CGATCG)₂ oligonucleotides the intercalation was demonstrated.