scholarly journals Effects of oat bran, processed to different molecular weights of β-glucan, on plasma lipids and caecal formation of SCFA in mice

2010 ◽  
Vol 104 (3) ◽  
pp. 364-373 ◽  
Author(s):  
Tina Immerstrand ◽  
Kristina E. Andersson ◽  
Caroline Wange ◽  
Ana Rascon ◽  
Per Hellstrand ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Propionic Acid ◽  
Plasma Lipids ◽  
Plasma Cholesterol ◽  
Control Diet ◽  
Cholesterol Lowering ◽  
Molecular Weights ◽  
Oat Bran ◽  
Diet Pattern ◽  
The Difference

In the present study, we evaluated the cholesterol-lowering effects of different oat bran (OB) preparations, differing regarding their peak molecular weight (MWp) of β-glucans (2348, 1311, 241, 56, 21 or < 10 kDa), in C57BL/6NCrl mice. The diets were designed to be atherogenic (0·8 % cholesterol and 0·1 % cholic acid), and they reflected the Western diet pattern (41 % energy fat). All OB preparations that were investigated significantly reduced plasma cholesterol when compared with a cellulose-containing control diet, regardless of the molecular weight of β-glucan. Moreover, the difference in viscous properties between the processed OB (from 0·11 to 17·7 l/g) did not appear to play a major role in the cholesterol-lowering properties. In addition, there was no correlation between the molecular weight of β-glucan and the amount of propionic acid formed in caecum. Interestingly, however, there was a significant correlation between the ratio of (propionic acid+butyric acid)/acetic acid and the MWpof β-glucans: the ratio increased with increasing molecular weight. The results of the present study suggest that the molecular weights and viscous properties of β-glucan in oat products may not be crucial parameters for their cholesterol-lowering effects.

scholarly journals Triterpenic Acids Present in Hawthorn Lower Plasma Cholesterol by Inhibiting Intestinal ACAT Activity in Hamsters

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Yuguang Lin ◽  
Mario A. Vermeer ◽  
Elke A. Trautwein
Keyword(s):  
Plasma Lipids ◽  
Plasma Cholesterol ◽  
Control Diet ◽  
Lipid Lowering ◽  
Lower Plasma ◽  
Sterol Esters ◽  
Cholesterol Lowering ◽  
Acat Activity ◽  
Lowering Effect ◽  
Cholesterol Lowering Effect

Hawthorn (Crataegus pinnatifida) is an edible fruit used in traditional Chinese medicine to lower plasma lipids. This study explored lipid-lowering compounds and underlying mechanisms of action of hawthorn. Hawthorn powder extracts inhibited acylCoA:cholesterol acyltransferase (ACAT) activity in Caco-2 cells. The inhibitory activity was positively associated with triterpenic acid (i.e., oleanolic acid (OA) and ursolic acid (UA)) contents in the extracts. Cholesterol lowering effects of hawthorn and its potential additive effect in combination with plant sterol esters (PSE) were further studied in hamsters. Animals were fed a semi-synthetic diet containing 0.08% (w/w) cholesterol (control) or the same diet supplemented with (i) 0.37% hawthorn dichloromethane extract, (ii) 0.24% PSE, (iii) hawthorn dichloromethane extract (0.37%) plus PSE (0.24%) or (iv) OA/UA mixture (0.01%) for 4 weeks. Compared to the control diet, hawthorn, PSE, hawthorn plus PSE and OA/UA significantly lowered plasma non-HDL (VLDL + LDL) cholesterol concentrations by 8%, 9%, 21% and 6% and decreased hepatic cholesterol ester content by 9%, 23%, 46% and 22%, respectively. The cholesterol lowering effects of these ingredients were conversely associated with their capacities in increasing fecal neutral sterol excretion. In conclusion, OA and UA are responsible for the cholesterol lowering effect of hawthorn by inhibiting intestinal ACAT activity. In addition, hawthorn and particularly its bioactive compounds (OA and UA) enhanced the cholesterol lowering effect of plant sterols.

Dependence of Tack Strength on Molecular Properties

1959 ◽  
Vol 32 (1) ◽  
pp. 48-66 ◽  
Author(s):  
W. G. Forbes ◽  
L. A. McLeod
Keyword(s):  
Molecular Weight ◽  
Shear Viscosity ◽  
Catalyst System ◽  
Chain Entanglement ◽  
Molecular Weights ◽  
Styrene Copolymers ◽  
The Difference ◽  
Catalyst Systems ◽  
Time Required ◽  
Butadiene Styrene

Abstract A method has been developed for the measurement of the tack strength of fresh and reproducibly smooth rubber surfaces. Using this method the tack strength of natural rubber is shown to be independent of polymer purity, and, to a large extent, Mooney viscosity, intrinsic viscosity, gel content and molecular weight distribution. The relative tack strengths of polyisoprenes of different molecular weights prepared in different catalyst systems are measured. The results are discussed in terms of microstructure. A study of the tack strength of oil-extended butadiene-styrene copolymers indicates that relative tack strength is related to the shear viscosity of the bulk polymer. Measurements of relative tack strength on Alfin and free radical butadiene-styrene copolymers, butyl, brominated butyl and butadiene-acrylonitrile copolymers confirm the inportance of shear viscosity in controlling tack strength. Choice of catalyst system and temperature of polymerization cause the largest variation in polymer viscosity. The contact time required for the relative tack strength to become unity is shown to be inversely dependent upon the value of the relative tack strength itself. Shear viscosity measurements are given for six classes of polymer and the values shown to correlate with relative tack strength. It is postulated that molecular weight (and probably also chain entanglement) is the controlling variable. The bond strength between two different uncured polymers is shown to depend upon the difference in cohesive energy densities of the two polymers.

Effects of dextran on microvascular ischemia-reperfusion injury in striated muscle

1997 ◽  
Vol 272 (4) ◽  
pp. H1710-H1716 ◽  
Author(s):  
M. Steinbauer ◽  
A. G. Harris ◽  
K. Messmer
Keyword(s):  
Molecular Weight ◽  
Reperfusion Injury ◽  
Striated Muscle ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Capillary Density ◽  
Vessel Diameter ◽  
Functional Capillary Density ◽  
Molecular Weights ◽  
The Difference

The objectives of this study were 1) to elucidate the effects of dextran (Dx) at a nonhemodiluting dose of 5 mg/kg on ischemia-reperfusion injury in striated muscle and 2) to investigate whether the effects are dependent on the molecular weight of Dx. We used the model of a 4-h pressure-induced ischemia in the hamster skinfold chamber. By means of intravital microscopy the following parameters were assessed: vessel diameter, red blood cell velocity, rolling and adherent leukocytes, macromolecular extravasation, and functional capillary density. The animals received a continuous infusion (total dose 5 mg/kg) of dextran of different molecular weights or equivalent volumes of saline. Seven groups were studied: NaCl (control, n = 6), Dx 1 (n = 6), Dx 40 (n = 7), Dx 60 (n = 6), Dx 70 (n = 7), Dx 110 (n = 7), and Dx 150 (n = 7). Leukocyte rolling was reduced by all Dx fractions, the difference from the control reaching significance 0.5 h after reperfusion in the Dx 60, Dx 70, and Dx 110 group, whereas leukocyte adherence was attenuated by > 40,000-mol-wt Dx at 0.5 h after reperfusion. Concomitantly, functional capillary density tended to improve after treatment with > or = 40,000-mol-wt Dx. However, all Dx fractions studied failed to reduce postischemic macromolecular extravasation. These results provide evidence that Dx at 5 mg/kg attenuates postischemic microvascular disturbances; this effect is molecular weight dependent.

scholarly journals Properties and structure of high temperature resistant cyanate ester/polyethersulfone blends using solvent-free toughening approach

2020 ◽  
Author(s):  
Lyaysan Amirova ◽  
Fabian Schadt ◽  
Markus Grob ◽  
Christian Brauner ◽  
Thomas Ricard ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Temperature ◽  
Network Formation ◽  
Mechanical Analysis ◽  
Solvent Free ◽  
Cyanate Ester ◽  
Low Molecular Weight ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
The Difference

AbstractA high temperature resistant novolac cyanate ester was blended with polyethersulfone (PES) with different molecular weights using the solvent-free approach. The phase separation, curing behavior and thermal properties were studied using hot stage microscopy, differential scanning calorimetry and dynamic mechanical analysis. Results showed the difference in the morphology for blends with different molecular weight PES explained by possible network formation. The influence of PES content on the glass transition temperature and mechanical properties was investigated. The most significant toughening effect (increase of 132% in fracture toughness) was achieved on a functionalized low molecular weight PES (20 parts per hundred of resin, phr). Rheology investigation allowed to estimate the optimal content of PES (15 phr) for further prepreg manufacturing.

MOLECULAR WEIGHTS FROM MICRO QUANTITIES OF MATERIALS

1949 ◽  
Vol 27b (3) ◽  
pp. 151-157 ◽  
Author(s):  
I. E. Puddington
Keyword(s):  
Molecular Weight ◽  
Vapor Pressure ◽  
Chemical Compounds ◽  
Unknown Compound ◽  
Molecular Weights ◽  
Pure Solvent ◽  
Unknown Substance ◽  
The Difference

A method is proposed for the determination of the molecular weight of chemical compounds in which the unknown substance may be used successfully m quantities of 1 mgm. or less. The method depends on the accurate measurement of the difference in vapor pressure between a solution of the unknown compound and the pure solvent, and this is accomplished with a modified mercury U-tube manometer. The results presented indicate that the difference between the experimental and theoretical molecular weights is of the order of 2%. Determinations require from two to three hours and the sample may be recovered.

scholarly journals Effects of inulin-type fructans on lipid metabolism in man and in animal models

2005 ◽  
Vol 93 (S1) ◽  
pp. S163-S168 ◽  
Author(s):  
Michel Beylot
Keyword(s):  
Propionic Acid ◽  
Acid Metabolism ◽  
Plasma Cholesterol ◽  
Plasma Lipid ◽  
Selective Exposure ◽  
Bile Acid Metabolism ◽  
Lipid Levels ◽  
Beneficial Effects ◽  
Glucose Levels ◽  
The Difference

Studies in rodents show that inulin and oligofructose can reduce the plasma levels of cholesterol and triacylglycerols (TG). In addition, they can oppose TG accumulation in liver and have favourable effects on hepatic steatosis. The hypotriglyceridaemic effect is due to a reduction in hepatic re-esterification of fatty acids, but mainly in the expression and activity of liver lipogenesis, resulting in lower hepatic secretion rate of TG. This repression of lipogenesis is not observed in adipose tissue. The effect on liver lipogenesis can be explained by reduced insulin/glucose levels or by a selective exposure of the liver to increased amounts of propionic acid produced in the large intestine during fermentation of non-digestible carbohydrates. The decrease in plasma cholesterol could also be due to inhibition of cholesterol synthesis by propionic acid or to modifications in the bile acid metabolism. Studies in man yield more conflicting results with a decrease or no effects on plasma lipid levels, and, when a decrease is observed, more marked effects on TG than on cholesterol and more consistent action of inulin than of oligofructose. Besides the difference in the dose of inulin or oligofructose used, differences in metabolic status could play a role in this discrepancy between man and animals since reduction in plasma TG is observed in man mainly in a situation of increased liver lipogenesis (high-carbohydrate diet, obesity, hypertriglyceridaemia). The effects on plasma cholesterol appear also more marked in hyperlipidaemic subjects than in healthy controls, suggesting that inulin and oligofructose have beneficial effects in these types of subjects.

scholarly journals Antioxidant Supplements Improve Profiles of Hepatic Oxysterols and Plasma Lipids in Butter-fed Hamsters

2010 ◽  
Vol 3 ◽  
pp. NMI.S3911 ◽  
Author(s):  
Johanne Poirier ◽  
Kevin A. Cockell ◽  
W.M. Nimal Ratnayake ◽  
Kylie A. Scoggan ◽  
Nick Hidiroglou ◽  
...  
Keyword(s):  
Plasma Lipids ◽  
Plasma Cholesterol ◽  
Saturated Fat ◽  
Cholesterol Homeostasis ◽  
Tocopheryl Acetate ◽  
High Cholesterol ◽  
Cholesterol Lowering ◽  
Enzymatic Production ◽  
Antioxidant Supplements ◽  
Tissue Lipid Peroxidation

Hypercholesterolemia diets are associated with oxidative stress that may contribute to hypercholesterolemia by adversely affecting enzymatically-generated oxysterols involved in cholesterol homeostasis. An experiment was conducted to examine whether the cholesterol-lowering effects of the antioxidants selenium and α-tocopherol were related to hepatic oxysterol concentrations. Four groups of male Syrian hamsters (n = 7-8) were fed high cholesterol and saturated fat (0.46% cholesterol, 14.3% fat) hypercholesterolemic semi-purified diets: 1) Control; 2) Control + α-tocopherol (67 IU all-racemic-α-tocopheryl-acetate/kg diet); 3) Control + selenium (3.4 mg selenate/kg diet); and 4) Control + α-tocopherol + selenium. Antioxidant supplementation was associated with lowered plasma cholesterol concentrations, decreased tissue lipid peroxidation and higher hepatic oxysterol concentrations. A second experiment examined the effect of graded selenium doses (0.15, 0.85, 1.7 and 3.4 mg selenate/kg diet) on mRNA expression of the oxysterol-generating enzyme, hepatic 27-hydroxylase (CYP27A1, EC 1.14.13.15), in hamsters (n = 8-9) fed the hypercholesterolemic diets. Supplementation of selenium at 3.4 mg selenate/kg diet was not associated with increased hepatic 27-hydroxylase mRNA. In conclusion, the cholesterol lowering effects of selenium and α-tocopherol were associated with increased hepatic enzymatically generated oxysterol concentrations, which appears to be mediated via improved antioxidant status rather than increased enzymatic production.

scholarly journals INFLUENCE OF PROPIONIC ACID ON THE CHOLESTEROL METABOLISM OF PIGS FED HYPERCHOLESTEROLEMIC DIETS

1981 ◽  
Vol 61 (4) ◽  
pp. 969-975 ◽  
Author(s):  
P. A. THACKER ◽  
M. O. SALOMONS ◽  
F. X. AHERNE ◽  
L. P. MILLIGAN ◽  
J. P. BOWLAND
Keyword(s):  
Propionic Acid ◽  
Cholesterol Metabolism ◽  
Plasma Cholesterol ◽  
Control Diet ◽  
Average Daily Gain ◽  
Cholesterol Content ◽  
Feed Conversion ◽  
Peripheral Tissues ◽  
Cholesterol Levels ◽  
Tissue Cholesterol

Sixty-four crossbred pigs averaging 24 kg liveweight were used to study the effects of dietary propionic acid (PA) on plasma and tissue cholesterol concentrations of pigs fed hypercholesterolemic diets for 10 wk. Four diets, based on barley, wheat and soybean meal, consisting of a control diet and a diet containing 10% tallow, both fed with and without the addition of 5% PA were used in this study. Addition of PA to the control diet decreased feed intake (ADF) by 16%, decreased average daily gain (ADG) by 8% and improved feed conversion efficiency (FCE) by 8%. Addition of tallow to the control diet resulted in a 15% reduction in ADF, a 3% improvement in ADG and an 18% improvement in FCE. When both tallow and PA were present, ADF was depressed 26%, ADG decreased 5% and FCE improved 23%. The addition of tallow significantly increased the levels of total plasma cholesterol while the addition of PA significantly decreased the plasma cholesterol levels in comparison with the control diet and prevented the increase noted in the tallow group. Addition of PA to the control diet significantly increased the cholesterol content of backfat and significantly reduced the cholesterol content of the kidneys. Addition of PA to the tallow diet significantly reduced the cholesterol content of kidneys, but did not significantly affect the cholesterol content of backfat. It is suggested that the increased cholesterol content of backfat in pigs fed diets containing PA reflects a reduced transport of cholesterol from peripheral tissues to the liver for excretion in the bile.

Effects of high molecular weight alcohols from sugar cane fed alone or in combination with plant sterols on lipid profile and antioxidant status of Wistar rats

2012 ◽  
Vol 37 (5) ◽  
pp. 938-946 ◽  
Author(s):  
David D. Kitts ◽  
Aneta Kopec ◽  
Jerzy Zawistowski ◽  
David G. Popovich
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Antioxidant Status ◽  
Wistar Rats ◽  
Plasma Lipids ◽  
Plasma Cholesterol ◽  
Radical Scavenging ◽  
Density Lipoprotein ◽  
Atherogenic Diet ◽  
Cholesterol Ratio

The effect of feeding a mixture of high molecular weight alcohols derived from sugarcane (SCA), both alone and in combination with phytosterols (PS), on changes in plasma lipids, organ cholesterol accumulation, and antioxidant status of Wistar rats was undertaken. Three separate experiments were conducted and each experiment had 3 subsets. In experiment 1, rats were fed on an AIN-76, semi-synthetic diet supplemented with 0%, 0.5%, and 5% SCA w/w. The second experiment consisted of feeding rats an atherogenic diet (AIN-76+0.5% cholesterol) containing 0%, 0.5%, and 5% SCA w/w. The third experiment consisted of feeding rats an atherogenic diet that contained 2% PS in combination with 0%, 0.5%, and 5% SCA. Rats fed the atherogenic diet exhibited significant elevations in total and low-density lipoprotein cholesterol, and significant reductions in the high-density lipoprotein/total cholesterol ratio, regardless of the presence of 0.5% or 5% SCA mixture. Serum cholesterol increased 29% to 35% in these animals compared with animals fed the nonatherogenic diets. In contrast, animals fed atherogenic diets that contained 2% PS exhibited no difference in serum lipids compared with counterparts fed nonatherogenic diets. The combined presence of SCA with PS had no effect on further lowering plasma cholesterol. No changes in C-reactive protein were observed, but plasma oxygen radical scavenging capacity values significantly (p < 0.05) decreased when rats were fed the atherogenic diets that contained the combination of PS and SCA. This result corresponded to an apparent greater (p < 0.05) susceptibility of red blood cells to oxidative stress

Long-term Effect of Sotalol on Plasma Lipids

1979 ◽  
Vol 57 (s5) ◽  
pp. 405s-407s ◽  
Author(s):  
A. Lehtonen ◽  
J. Viikari
Keyword(s):  
Total Cholesterol ◽  
Plasma Lipids ◽  
Plasma Cholesterol ◽  
Hdl Cholesterol ◽  
Plasma Free Fatty Acid ◽  
Cholesterol Concentration ◽  
Plasma Total Cholesterol ◽  
Long Term Effect ◽  
The Difference

1. We studied the effect on plasma lipids of sotalol given orally over a 12 month period to patients with essential hypertension. 2. Plasma free fatty acid concentration was lower than initially at 1, 3, 6 and 12 months. The difference was significant (P &lt; 0·01) at 1 and 3 months. 3. Plasma cholesterol (VLDL + LDL-cholesterol) increased during treatment. Plasma total cholesterol increased from 5·49 ± sd 0·94 mmol/l at the beginning to 6·37 ± 1·10 mmol/l at 12 months (P &lt; 0·01). 4. HDL-cholesterol concentration and the ratio of HDL-cholesterol to total cholesterol decreased significantly. The ratios were 0·28 and 0·18 at the beginning and at 12 months respectively (P &lt; 0·001). 5. Plasma triglycerides increased simultaneously from 1·14 ± 0·31 to 1·89 ± 0·99 mmol/l (P &lt; 0·01).

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