Oxygen-Dependent Processes in Monocytes and Metabolic Risk Factors for Atherogenesis

Oxygen-dependent processes in peripheral blood monocytes were intensified in patients with metabolic cardiovascular syndrome. This was manifested in increased production of O(2)(*-) and NO. Among metabolic factors (cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerols, glucose, etc.), products of glycosylation (fructosamine) and plasma triacylglycerols were most potent in modulating generation of O(2)(*-) and NO by monocytes.     

Bacterial Chemotaxis: Biochemistry of Behavior in a Single Cell

Abstract

Lipases are esterases able to hydrolyze water-insoluble esters such as long-chain triglycerides. These enzymes also catalyze the formation of esters (esterification) and the exchange of ester bonds (transcsterification) when present in nonaqueous media. Lipases display a high degree of specificity and enantioselectivity for esterification and transesterification reactions, and thus their potential uses in industry are very wide. These potential industrial applications have been an important driving force for lipase research during the last several years, and in particular for the study of lipases produced by microorganisms. Pseudomona lipases are very interesting because they display special biochemical characteristics not common among the lipases produced by other microorganisms, such as their thermoresistance and activity at alkaline pHs. Recently, several Pseudomonas genes have been cloned and sequenced, and the regulation of their expression is beginning to be understood. The molecular genetic approach to the study of Pseudomonas lipases will permit the construction of recombinant strains with increased lipase productivity and will provide the opportunity to modify these enzymes to suit particular industrial applications.     

Eicosapentaenoic acid ethyl ester supplementation in cachectic cancer patients and healthy subjects: effects on lipolysis and lipid oxidation

BACKGROUND & AIMS: Recent reports suggest that weight loss in cachectic cancer patients may be inhibited by supplementation of the n-3 fatty acid eicosapentaenoic acid (20:5n-3; EPA), presumably due to inhibition of lipolysis. The aim of the present double-blind, randomized trial was to assess whether short-term oral EPA ethyl ester (EE) supplementation inhibits lipolysis and lipid oxidation in weight-losing cancer patients and in healthy subjects. METHODS: Seventeen weight-losing, cancer patients of different tumor types, and 16 healthy subjects were randomized to receive EPA-EE (6 g/d) or placebo (oleic acid (OA)-EE; 6 g/d) for seven days. At baseline (day 0) and during supplementation (days 2 and 7) whole-body lipolysis and palmitic acid release were measured in the overnight fasting state using [1, 1, 2, 3, 3-(2)H(5)]glycerol and [1-(13)C]palmitic acid. Palmitate oxidation was determined by measuring(13)CO(2)enrichment in expired breath. RESULTS: No significant effects of EPA-EE on whole-body lipolysis, palmitic acid release, or palmitate oxidation were detected in cancer patients nor in healthy subjects in comparison with OA-EE. EPA-EE supplementation reduced plasma-free fatty acid and triacylglycerol concentrations significantly in healthy subjects but not in cancer patients. CONCLUSION: We conclude that supplementation of EPA-EE does not significantly inhibit lipolysis or lipid oxidation in weight-losing cancer patients or in healthy subjects during short-term supplementation when using OA-EE as a placebo supplement.     

Resistance of HepG2 cells against the adverse effects of ethanol related to neutral lipid and phospholipid metabolism

The influence of both short- and long-term ethanol exposure on the lipid metabolism was determined in the human hepatoma cell line HepG2. Ethanol did not cause any cytotoxicity or lipid peroxidation even after 7 days of 100 mM ethanol treatment of HepG2 cells. Incubation of cells in the presence of [1-(14)C]ethanol demonstrated that these cells actively metabolize ethanol to acetyl CoA, incorporating the radioactive label into neutral lipids and phospholipids. [1,2,3-(3)H]glycerol was efficiently used in phospholipid and neutral lipid biosynthesis, showing higher radioactivity in phosphatidylcholine, phosphatidylethanolamine and triacylglycerols. Exposure of HepG2 cells to 100 mM ethanol for 24 hr did not significantly modify the incorporation of glycerol into newly synthesized phospholipids and neutral lipids, nor was lipid degradation affected by the presence of ethanol. When the alcohol treatment was prolonged for 7 days, incorporation of [1,2,3-(3)H]glycerol into triacylglycerols and diacylglycerols showed a slight increase concomitantly with decreased radioactivity in the major phospholipids, phosphatidylcholine and phosphatidylethanolamine. In addition, these changes were associated with a greater release of radiolabeled triacylglycerols into the culture medium. These results indicate that ethanol does not cause in HepG2 cells the marked lipogenic stimulation widely shown in hepatocytes, and demonstrate that HepG2 cells strongly resist the adverse effects of ethanol. Since these cells lack the isoenzymatic form of cytochrome P(450) mainly involved in the ethanol metabolism (namely cytochrome P(450)2E1) and also are devoid of alcohol dehydrogenase activity, we propose that the toxic actions of ethanol on liver must be linked to the activity of one or both of these systems.     

Diets high in conjugated linoleic acid from pasture-fed cattle did not alter markers of health in young women

Conjugated linoleic acid (CLA) purportedly alters body composition, glucose tolerance, hepatic function, lipoprotein distributions, and other markers of health. Results are often inconclusive or contradictory, and presently, no studies have investigated the effects of naturally incorporated CLA from pasture-fed beef and dairy products on human health. We hypothesized that a diet comprised of foods naturally enriched with CLA from pasture-fed cattle would result in improved insulin sensitivity, body composition, circulating lipids, and other disease risk factors when compared to a diet comprised of commercial foods naturally low in CLA from grain-fed cattle. Eighteen healthy women 20 to 39 years of age consumed one of these 2 diets for 56 days. Balanced nutritionally complete diets comprised of 31% energy from lipid, 13% from protein, and 54% from carbohydrate were administered, with the primary difference being CLA content (CLA diet: 1.17 g/d; control diet: 0.35 g/d). The CLA diet did not result in any differences in insulin sensitivity, body composition, circulating blood lipids, or other measured disease risk factors as compared with the control diet. Thus, we conclude that a diet naturally enriched with over a 3-fold increase in CLA from pasture-fed cattle did not significantly alter selected health risk factors in healthy, premenopausal women as compared with a similar diet composed of foods from grain-fed cattle.     

Variation in fatty acid distribution of different acyl lipids in rice (Oryza sativa L.) brans

The lipids extracted from rice brans were classified by thin-layer chromatography into eight fractions, and their fatty acid (FA) compositions were investigated among five different Japanese cultivars. The lipids of these rice brans comprised mainly triacylglycerols (TAG; 84.9-86.0 wt%), free FA (4.2-4.6 wt%), and phospholipids (PL; 6.5-6.7 wt%), whilst other components were also detected in minor proportions (0.2-2.1 wt%). The PL components included phosphatidyl choline (43.3-46.8 wt%) phosphatidyl ethanolamine (25.0-27.3 wt%) and phosphatidyl inositol (20.2-23.2 wt%). Comparison of the different cultivars showed, with a few exceptions, no substantial difference (P > 0.05) in FA distribution. FA distribution of TAG among the five cultivars was characterized as: unsaturated FA predominantly concentrated at the sn-2 position and saturated FA primarily occupying the sn-1 or sn-3 position in these lipids. These results suggest that the rice bran lipids may be well incorporated into our daily diet to improve nutritional value of the Japanese diet.     

Determinants of intramyocellular lipid accumulation after dietary fat loading in non‐obese men

Aims/Introduction:  Accumulation of intramyocellular lipid (IMCL) is associated with insulin resistance. However, the factors affecting the change in IMCL remain to be elucidated. The aim of the present study was to determine the factors that influence the change in IMCL level after high‐fat loading.Materials and Methods:  The study subjects were 37 non‐obese men. Each subject consumed a high‐fat diet for 3 days after a normal‐fat diet for 3 days. After each diet program, IMCL levels in the tibialis anterior (TA‐IMCL) and soleus (SOL‐IMCL) were measured by proton magnetic resonance spectroscopy. Glucose infusion rate (GIR) was evaluated by euglycemic hyperinsulinemic clamp as an index of peripheral insulin sensitivity.Results:  The high‐fat diet significantly increased TA‐IMCL and SOL‐IMCL by ∼30 and ∼20%, respectively (P < 0.05), whereas it did not significantly alter GIR. The increase in SOL‐IMCL, but not in TA‐IMCL, negatively correlated with serum high molecular weight (HMW)‐adiponectin (r = −0.36, P < 0.05) and HMW‐/total‐adiponectin ratio (r = −0.46, P < 0.05). Although high‐fat diet‐related changes in SOL‐IMCL showed high inter‐individual variations, in subjects doing exercise, changes in SOL‐IMCL (r = 0.55, P < 0.05) and TA‐IMCL (r = 0.61, P < 0.05) positively correlated with daily physical activity level. In contrast, in sedentary subjects, changes in SOL‐IMCL (r = −0.50, P < 0.01) and TA‐IMCL (r = −0.48, P < 0.05) negatively correlated with daily physical activity.Conclusions:  HMW‐adiponectin and daily physical activity are determinants of IMCL accumulation by a high‐fat diet. Intriguingly, the effect of daily physical activity on the change in IMCL depends on the level of regular exercise. (J Diabetes Invest,doi: 10.1111/j.2040‐1124.2010.00091.x, 2011)     

Regiospecific profiles of fatty acids in triacylglycerols and phospholipids from Adzuki beans (Vigna angularis)

Regiospecific distributions of fatty acids (FA) of triacylglycerols (TAG) and phospholipids (PL) isolated from five cultivars of adzuki beans (Vigna angularis) were investigated. The lipids comprised mainly PL (72.2-73.4 wt-%) and TAG (20.6-21.9 wt-%), whilst other components were detected in minor proportions (0.1-3.4 wt-%). The principal profiles of the FA distribution in the TAG and PL were evident in the beans among the five cultivars: unsaturated FA were predominantly distributed in the sn-2 position, whilst saturated FA primarily occupied the sn-1 or the sn-3 position in the these lipids. The results would be useful information to both producers and consumers for manufacturing traditional adzuki confectionaries such as wagashi in Japan.     

Quantification and characterization of aortic cholesterol in rabbits fed a high-cholesterol diet

Determination of fat percentage of aortic intimal area stained by Sudan III is useful as an index of atherosclerosis in the rabbit animal model. However, the determination of sudanophilic area of the thoracic aorta is two-dimensional and does not measure the third dimension of depth. The objective of the present study was to quantify and characterize aortic lipids using the gas–liquid chromatographic (GLC) technique and to determine whether elevated measurements of total cholesterol and cholesteryl esters was correlated with increased measurements of sudanophilic area staining of the thoracic aorta in rabbits given either a normal chow or a 1% cholesterol diet. The GLC results showed that there was a mean accumulation of 10.9 mg of cholesterol per gram of aortic tissue in the rabbits given a cholesterol diet (mean sudanophilic area of 23.8%). In contrast, rabbits on a normal chow diet had only a deposition of 0.58 mg of cholesterol per gram of the aortic tissue diet (mean sudanophilic area of 1.4%). The present study suggests that quantification of the aortic lipids can be performed by using GLC techniques and that it could be used as an alternative to the measurement of sudanophilic area when assessing the severity of atherosclerosis.     

狗脊毛甲醇提取物UPLC/Q-TOF-MS分析

目的：探索狗脊毛化学成分组成及其外用止血的物质基础。方法：采用超声、索氏、回流3种方式对狗脊毛进行甲醇提取,通过UPLC/Q-TOF-MS对各提取物进行定性分析,流动相乙腈（A）-水（B）梯度洗脱（0~5 min,5%~55% A;5~7 min,55%~85% A;7~15 min,85%~100% A;15~20 min,100% A）,检测波长254 nm,m/z扫描范围100~1 000,脱溶剂气温度350 ℃,脱溶剂气体积流量9 L·min^-1,喷雾器压力2.4×10⁵Pa,毛细管电压4 000 V。结果：3种方式共检出化合物50个,给出了其中38个化合物的推荐分子式和名称。编号32~39共8个化合物为一系列三酰基甘油类同系物。结论：狗脊毛中化合物包括植物油类（三酰基甘油）、有机酸类、有机酸酯类、生物碱类、黄酮类、多酚类、糖苷类等,相对分子质量集中于200~800,三酰基甘油可能为主要药效成分。