triolein and tristearin

We investigate the phase behavior of model ternary triacylglycerol blends, comprising triolein (C

Topics: Crystallization; Triglycerides; Triolein; X-Ray Diffraction

The proliferating effects of 3 different simple triglycerides (tristearin, triolein, and trilinolein) on the human umbilical vein smooth muscle cells (HUVSMCs) induced by oxidized-LDL (ox-LDL) were investigated in this study. The protein and mRNA gene expressions of proliferating cell nuclear antigen (PCNA), smooth muscle-α-actin (SM-α-actin), and monocyte chemoattractant protein-1 (MCP-1) in HUVSMCs were measured by Western blotting and real-time quantitative polymerase chain reaction (PCR). It was shown that in tristearin (SSS) treated HUVSMCs, the saturated fatty acid content was increased, and the compositions of polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid were decreased significantly. On the other hand, triolein (OOO) and trilinolein (LLL) significantly increased the levels of some typical PUFA such as arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. Moreover, LLL and OOO could upregulate the protein and mRNA expressions of PCNA, MCP-1 as well as downregulate the expression of SM-α-actin. The results also showed that, SSS had significant promotion effects on the proliferation of HUVSMCs induced by ox-LDL. Although both LLL and OOO could inhibit the proliferation of HUVSMCs induced by ox-LDL, and might have certain inhibition of the atherosclerotic process.

Topics: Actins; Atherosclerosis; Cells, Cultured; Chemokine CCL2; Fatty Acids, Unsaturated; Gene Expression; Gene Expression Regulation; Humans; Lipoproteins, LDL; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Proliferating Cell Nuclear Antigen; Triglycerides; Triolein

Second generation lipid systems for the delivery of bioactive compounds have been developed by mixing a liquid carrier oil with a solid lipid to form so-called nanostructured lipid carriers (NLCs). In this study, we investigated the effect of different liquid carrier oils on the crystallization and aggregation behavior of tristearin NLC dispersions. We found that NLC suspension stability was strongly affected by the type and amount of the carrier oil. As the oil concentration was increased, the crystallization and melting temperatures decreased, the polymorphic transformation rate increased, the particles became more spherical, and suspension stability was enhanced. These results suggest that oil trapped within the growing crystal matrix accelerated polymorphic transformation but retarded the large shape change normally associated with the transformation. We also found that considerably less surfactant was necessary to produce stable NLC suspensions than was required to stabilize solid lipid nanoparticle (SLN) suspensions without a carrier oil. Based on preliminary simulation results, we hypothesized that improved NLC suspension stability was attributable to both reduced particle shape change, which created less new surface area to be covered by surfactant, and increased mobility of surfactant molecules, which resulted in available surfactant being more efficient at covering created surface area.

Topics: Alkanes; Calorimetry, Differential Scanning; Caprylates; Crystallization; Drug Carriers; Drug Stability; Flocculation; Microscopy, Electron, Transmission; Nanostructures; Oleic Acid; Olive Oil; Palm Oil; Particle Size; Phase Transition; Plant Oils; Polysorbates; Surface-Active Agents; Suspensions; Triglycerides; Triolein

A one-pot catalytic hydrolysis-deoxygenation reaction for the conversion of unsaturated triglycerides and free fatty acids to linear paraffins and olefins is reported. The hydrothermal deoxygenation reactions are performed in hot compressed water at 250 °C over a Pd/C catalyst in the absence of external H2 . We show that aqueous-phase reforming (APR) of glycerol and subsequent water-gas-shift reaction result in the in situ formation of H2 . While this has a significant positive effect on the deoxygenation activity, the product selectivity towards high-value, long-chain olefins remains high.

Topics: Biofuels; Carbon; Catalysis; Fatty Acids; Glycerol; Hydrogen; Oxygen; Plant Oils; Platinum; Temperature; Triglycerides; Triolein

Polycrystalline particles composed of triacylglycerol (TAG) molecules, and their networks, in anhydrous TAG oils find extensive use as edible oils in the food industry. Although modelling studies of TAG systems, have been carried out, none have attempted to address a problem of central concern to food science and technology: the "oil binding capacity" of a system of such edible oils. Crystalline nanoparticles (CNPs) have recently been identified as the fundamental components of solid fats in oils. Oil binding capacity is an important concept regarding the ability of fats particles to retain oil, and the ability of these CNPs to bind oil is important in designing healthy foods. We have carried out atomic scale molecular dynamics computer simulations to understand the behavior of a triacylglycerol oil (triolein) in nanoscale confinements between tristearin CNPs. We define a nanoscale oil binding capacity function by utilizing the average oil number density, 〈Φ(d)〉, between two CNPs as a function of their separation, d. We modelled pure tristearin CNPs as well as tristearin CNPs in which the surfaces are covered with an interface comprising soft permanent coatings. Their surfaces are "hard" and "soft" respectively. We found that for a pair of hard-surface tristearin CNPs a distance d apart, (i) triolein exhibits number density, and therefore density, oscillations as a function of d, and (ii) the average number density between two such CNPs decreases as d decreases, viz. the oil binding capacity is lowered. When a soft layer of oil covers the CNP surfaces, we found that the oscillations are smeared out and that the average number density between the two CNPs remained approximately constant as d decreased indicating a high oil binding capacity. Our results might have identified important nanoscale aspects to aid in healthy food design.

Topics: Computer Simulation; Models, Chemical; Nanoparticles; Nanotechnology; Oils; Triglycerides; Triolein

A wide range of lipids are present on the skin surface of human beings and bacterial lipases are known to modify them. The microflora of the underarm (axilla) is often dominated by aerobic coryneforms and whilst many require lipids for growth, they appear not to be utilized as carbon sources. The aim of this study was to investigate the adherence aerobic coryneforms to lipids present on the skin surface of the human axilla to determine whether they contribute to colonization of the skin.. Aerobic coryneforms were grown in a defined synthetic medium in the presence of (14)C-glucose to produce radio-labelled cells. Adherence to lipids was tested using a thin layer chromatography plate-based assay.. The mechanism of bacterial adhesion to skin lipids is unknown. The results of this study show that a significant proportion of cutaneous aerobic coryneform isolates from the axilla interact with skin lipids resulting in increased adherence, which may contribute to skin colonization.

Topics: Actinomycetales; Axilla; Bacteria, Aerobic; Bacterial Adhesion; Carbon Isotopes; Cholesterol; Cholesterol Esters; Diglycerides; Glycerides; Linoleic Acid; Lipid Metabolism; Oleic Acid; Skin; Squalene; Stearic Acids; Triglycerides; Triolein

While it is well established that the fatty acid composition of dietary fat is important in determining plasma lipoprotein cholesterol concentrations, the effects of changing the absolute quantities of the individual fatty acids are less clear. In the present study Golden Syrian hamsters were fed on isoenergetic, low cholesterol (0.05 g/kg) diets containing 100, 150 or 200 g added fat/kg. This consisted of triolein (TO) alone, or equal proportions of TO and either trimyristin (TM), tripalmitin (TP) or tristearin (TS). Each trial also included a control group fed on a diet containing 50 g TO/kg. As the mass of TO in the diet increased, plasma VLDL-cholesterol concentrations rose. The TM-rich diets produced a concentration-dependent increase in total plasma cholesterol which was a result of significant increases in both VLDL and HDL levels. The TP-rich diets increased plasma LDL- and HDL-cholesterol levels in a concentration-dependent manner. TS-containing diets did not increase the cholesterol content of any of the major lipoprotein fractions. Hepatic LDL-receptor mRNA concentrations were significantly decreased in animals fed on TP, while apolipoprotein B mRNA concentrations were significantly increased. Thus, on a low-cholesterol diet, increasing the absolute amount of dietary palmitic acid increases LDL-cholesterol more than either myristic or stearic acid. These effects on lipoprotein metabolism may be exerted through specific modulation of the expression of the LDL receptor and apolipoprotein B genes.

Topics: Animals; Apolipoproteins B; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cholesterol, VLDL; Cricetinae; Diet; Fatty Acids; Lipoproteins; Liver; Male; Mesocricetus; Receptors, LDL; RNA, Messenger; Triglycerides; Triolein

Surface enhanced Raman spectroscopy (SERS) at a silver microelectrode was used to monitor bacterial hydrolysis of triglycerides in lipid mixtures that model sebaceous gland secretions. Mixtures of wax esters, squalene, triolein, and triisostearin were used as model skin secretions. The transformation was followed in vitro as changes in the SERS caused by hydrolysis of triglyceride to fatty acid. The fatty acid was adsorbed as its carboxylate, which is readily identified by the characteristic band at ca. 1395 cm(-1). Co-adsorption of propionate was also observed. The technique can also confirm the presence of bacteria by detection of short chain carboxylic acids released as products of fermentation during the growth of these cells.

Topics: Esters; Hydrolysis; Lipid Metabolism; Models, Biological; Propionibacterium acnes; Sebaceous Glands; Spectrum Analysis, Raman; Squalene; Triglycerides; Triolein; Waxes

Topics: Analysis of Variance; Animals; Cholesterol, Dietary; Cholesterol, LDL; Cricetinae; Dietary Fats; Liver; Male; Mesocricetus; Transcription, Genetic; Triglycerides; Triolein

The effect of dietary fat on hepatic microsomal triglyceride transfer protein(MTP) large subunit mRNA levels in the hamster was examined. Increasing the dietary fat concentration from 11.7 energy % to 46.8 energy % caused a 60% increase in hepatic MTP mRNA; this increase was shown to be dose-dependent (r = 0.688 p = 0.0023). MTP mRNA levels correlated significantly with several plasma lipoprotein cholesterol parameters. No significant relationship was observed between MTP mRNA and either plasma or VLDL triglyceride. The nature of the dietary fatty acids also influenced MTP mRNA levels, with trimyristin and tripalmitin enriched diets significantly elevating MTP mRNA relative to diets enriched in triolein and trilinolein.

Topics: Animals; Carrier Proteins; Cholesterol Ester Transfer Proteins; Cricetinae; Dietary Fats; Energy Intake; Gene Expression Regulation; Glycoproteins; Male; Mesocricetus; Microsomes, Liver; RNA, Messenger; Triglycerides; Triolein

To study the effects of medium-chain triacylglycerols (MCT) on maternal lipid metabolism and pup growth, MCT (200 g/kg) were incorporated into a commercial chow diet and fed to lactating rats for 8-10 d. The results were compared with similar diets containing sunflower oil (polyunsaturated fatty acids; PUFA), tristearin (saturated fatty acid) or triolein (monounsaturated fatty acid). There was decreased food and energy intake with the MCT diet and this was accompanied by decreased (35%) pup growth. All the high-fat diets inhibited lipogenesis in vivo in the lactating mammary gland, the order of effectiveness being PUFA > triolein > tristearin > MCT. Only the MCT diet increased the rate of hepatic lipogenesis (180%). Experiments feeding an MCT meal containing [1-14C]octanoate indicated that very little (3-4%) of the C was present in mammary gland lipid, unlike the findings with [1-14C]triolein meal (40%). The major portion (65%) of the absorbed [1-14C]octanoate was oxidized to 14CO2. There was no evidence for adaptation of the mammary gland to increased dietary lipid uptake on the triolein or MCT diets. It is concluded that the decreased pup growth on the MCT diet is due in part to the decreased energy intake and to the inability of dietary medium-chain fatty acids to provide substrates for milk lipid synthesis.

Topics: Animals; Animals, Suckling; Dietary Fats, Unsaturated; Fatty Acids; Female; Lactation; Lipid Metabolism; Mammary Glands, Animal; Plant Oils; Pregnancy; Rats; Rats, Wistar; Sunflower Oil; Triglycerides; Triolein

The goal of the present study was to determine 1) whether the poor digestion and absorption of glycerol tristearate (TS) that we observed previously is due to amount fed and 2) whether the digestion, absorption, and lymphatic transport of TS is affected by the presence of either a saturated fat [glycerol tripalmitate (TP)] or a monounsaturated fat [glycerol trioleate (TO)]. Three groups of intestinal lymph fistula rats were used. Group A was fed a lipid emulsion containing 12.5 mumol of TS (labeled as [glyceryl-1,3-14C]tristerate), 7.8 mumols of egg phosphatidylcholine, and 57 mumols of sodium taurocholate in 3 ml of phosphate-buffered saline per hour for 8 h. Group B rats were fed the same emulsion as group A, but with 12.5 mumols of TO added. Group C rats had 12.5 mumols of TP instead of TO added to the group A emulsion. The lymphatic radioactivity and triglyceride outputs were significantly lower in group A, with group C next and group B having the highest outputs. Significantly more TS remained in the lumen of the group A rats compared with groups B and C. The majority of the radioactivity in the lumen was still in the TS form in all three groups, indicating poor lipolysis. However, once the fatty acid and monoglyceride were absorbed, the reesterification process was similar in all three groups. When we studied the ability of the three groups of animals to transport the absorbed lipid into lymph (lymph transport index), both groups B and C were significantly better than group A rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Chromatography, High Pressure Liquid; Chylomicrons; Fatty Acids; Intestinal Absorption; Intestinal Mucosa; Intestines; Lipid Metabolism; Lipoproteins, VLDL; Lymph; Lymphoid Tissue; Male; Phospholipids; Rats; Rats, Inbred Strains; Tissue Distribution; Triglycerides; Triolein

Generally, fats rich in saturated fatty acids raise serum cholesterol, whereas fats rich in polyunsaturated fatty acids lower it. There appear to be exceptions; e.g., stearic acid (18:0)-rich fats have little or no effect on serum cholesterol concentrations. This apparent lack of cholesterolemic effect of stearic acid-rich fat could be because intestinal absorption of fat is poor or subsequent plasma and/or tissue metabolism of fat is different. To investigate mechanisms involved, we compared intestinal digestion, uptake, and lymphatic transport of glycerol tristearate (TS) and glycerol trioleate (TO, 18:1). Two groups of rats bearing intestinal lymph fistulas were used. TO rats were fed intraduodenally for 8 h at a constant rate a lipid emulsion of 25 mumols/h of TO (labeled with glycerol tri[9,10 (n)-3H]oleate), 7.8 mumols of egg phosphatidylcholine, and 57 mumols of sodium taurocholate in 3 ml of phosphate-buffered saline. TS rats were fed the same lipid emulsion except that TS replaced TO and the emulsion was labeled with glyceryl [1,3-14C]tristearate. The lymph triglyceride and radioactivity were determined. After infusion, the luminal and mucosal radioactive lipid content was analyzed. The results showed that there was significantly less lipid transported in the lymph of TS rats compared with TO rats. The results also showed a significant decrease in the absorption of TS as compared with TO. This was due in part to poor lipolysis. In addition, the lipid absorbed by the intestine of the TS rats was transported into lymph less efficiently than in TO rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Eating; Fasting; Intestinal Absorption; Intestinal Mucosa; Intestine, Small; Kinetics; Lymph; Male; Muscle, Smooth; Radioisotope Dilution Technique; Rats; Rats, Inbred Strains; Time Factors; Triglycerides; Triolein; Tritium

Adult male rats were fed a semi-purified diet containing 20 p. 100 of lard or homogeneous triglycerides (tripalmitin, tristearin, triolein, trierucin) for 4 months. The rates of the processes (absorption, synthesis, degradation into bile acids, fecal and urinary excretion) involved in cholesterol turnover were measured using the isotope equilibrium method. The absorption coefficient of dietary cholesterol attained 71 +/- 3 p. 100 in rats fed the lard diet. It was unchanged in rats eating the triolein (73 +/- 3 p. 100) or tripalmitin (75 +/- 4 p. 100) diet but was drastically reduced in those receiving trierucin (45 +/- 1 p. 100) or tristearin (34 +/- 1 p. 100). Some functional and topological aspects of cholesterol absorption are discussed. Four to 6 times more endogenous cholesterol was found in the intestinal lumen of rats fed trierucin than in that of rats receiving a normolipid diet. Micelle cholesterol increase was also proportionally less. There was no direct relationship between the quantity of cholesterol found in the micelles and that absorbed. Dietary cholesterol was absorbed in the second as well as in the first half of the intestine, while the proportions of micellar cholesterol decreased continuously from the jejunum to the ileum. The rates of fecal excretion and fecal external secretion were inversely correlated to the absorption coefficient of dietary cholesterol, as has been previously described. The internal secretion was stimulated two to threefold in rats fed tristearin (22.3 +/- 0.7 mg/d), tripalmitin (28.4 +/- 4.6 mg/d) and trierucin (33.2 +/- 2.8 mg/d) as compared to rats fed lard (12.5 +/- 0.6 mg/d) or triolein (14.4 +/- 1.2 mg/d). Feeding a tripalmitin or a trierucin diet greatly increased cholesterogenesis (probably in the liver), while tristearin stimulated non-hepatic cholesterogenesis. The variations in daily bile acid elimination may be seen as an adaptive parameter, modulating its rate according to the cholesterol supply (absorption and synthesis).

Topics: Animals; Cholesterol; Dietary Fats; Erucic Acids; Feces; Intestinal Absorption; Intestinal Mucosa; Male; Rats; Rats, Inbred Strains; Tissue Distribution; Triglycerides; Triolein

Diets containing relatively homogeneous triglycerides composed of 18-carbon chain saturated, monounsaturated or polyunsaturated fatty acids were fed to rats. Cholesterol absorption and turnover were studied. Cholesterol absorption was significantly less in rats fed tristearin than in animals fed triolein or safflower oil. Cholesterol removal from plasma was fastest in rats fed tristearin and slowest with safflower oil and triolein. Plasma cholesterol levels were lowest with tristearin and highest with safflower oil. Increased cholesterol in high density lipoproteins was observed with tristearin and triolein. Lymph and hepatic cholesterol, and lymph triglycerides were highest with safflower oil, suggesting endogenous mobilization. Cholesterol production was least with triolein. Sterol synthesis was greatest with tristearin, perhaps attributable to decreased negative feedback analogous to effects of cholestyramine. Differences in lipoprotein composition observed with the various diets are important since effects on particle size and shape may influence removal mechanisms. The mechanisms underlying the different effects of dietary triglycerides on sterol absorption and metabolism remain to be elucidated.

Topics: Animals; Cholesterol; Dietary Fats; Kinetics; Lipoproteins; Liver; Lymph; Male; Oils; Rats; Safflower Oil; Stearates; Stearic Acids; Structure-Activity Relationship; Triglycerides; Triolein