• Applied Biological Chemistry
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• v.16 no.3
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• pp.112-117
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• 1973

The very low density apolipoproteins were separated by a newly developed method of isoelectric focusing in a narrow pH gradient. Four polypeptides were isolated that differed from the major proteins of the high density or low density lipoproteins. Three of these proteins had indistinguishable amino acid compositions, but different isoelectric points, COOH-terminal alanine, no isoleucine, cysteine or cystine. Two of these polypeptides had $NH_2-terminal$ serine. The polymorphism of apolipoprotein-Ala, so designated from the COOH-terminal residue, was related to sialic acid content; one form contained 2 moles of sialic acid per mole of protein, the second, 1 mole of protein, and the third, no sialic acid. The fourth polypeptide had an amino acid composition different from the first three polypeptides and from other polypetides obtained from very low density lipoprotein. This polypeptide had $NH_2-terminal$ threonine, COOH-terminal resistant to carboxypeptidase A, no histidine, cysteine, cystine or sialic acid. These four polypeptides constituted approx. 40% of the total protein in very low density lipoprotein.

• BMB Reports
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• v.45 no.10
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• pp.565-570
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• 2012

We recently reported that a water extract of laurel or turmeric, 1,8-cineole enriched fractions, showed hypolipidemic activity in the zebrafish model. Therefore, the present study investigated the cineole's anti-oxidant and anti-inflammatory activities in lipoprotein metabolism in vitro and in vivo. Cineole had inhibitory effects on cupric ion-mediated oxidation of lipoproteins in general, while simultaneously enhancing ferric ion removal ability in high-density lipoprotein (HDL). Hypercholesterolemia was induced in zebrafish using cholesterol-feeding treatment, 4% cholesterol, for 3 weeks. After feeding with or without the addition of cineole, the results revealed that cineole possessed lipid-lowering and anti-inflammatory activities in hypercholesterolemic zebrafish. In addition, serum amyloid A and interleukin-6 levels were lowered and lipid accumulation was decreased in the liver. Conclusively, 1,8-cineole was found to have anti-oxidant activities in lipoprotein metabolism both in vitro and in vivo with simultaneous reduction of lipid accumulation in the liver of zebrafish.

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.133-138
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• 2002

To examine the cholesterol-towering effects of extruded products made with cassava starch (CS) and blends of cassava starch with either resistant starch (CS-RS) or oat fiber (CS-OF) hamsters were fed with diets containing a high-cholesterol (2%) and high-fat (17%) diet for 20 days. Hamsters fed with a diet containing no cholesterol were used as a control. Total cholesterol (TC) levels in the CS-RS and CS-OF groups were significantly (p>0.05) lower compared to the CS group by 11.5% and 8.5%, respectively. Also, the diets containing fibers decreased the value of low-density lipoproteins plus very low-density lipoproteins fraction by 32.4% (CS-RS diet) and 51.7% (CS-OF), respectively, as compared to the CS diet. Total lipid values were significantly (p<0.05) lower in hamsters fed the CS-RS diet (916 mg/dL) and CS-OF diet (964 mg/dL) as compared to those fed the CS diet (1661 mg/dL). The results obtained in this study suggest that extruded products containing cassava starch blended with either resistant starch or oat fleer, could prevent health problems associated with high levels of cholesterol and hypertriglyceridemia induced by a high cholesterol and fat diet.

• Nutrition Research and Practice
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• v.4 no.6
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• pp.492-498
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• 2010

Both metabolic syndrome (MetS) and elevated LDL cholesterol (LDL-C) increase the risk for cardiovascular disease (CVD). We hypothesized that low HDL cholesterol (HDL-C) would further increase CVD risk in women having both conditions. To assess this, we recruited 89 women with MetS (25-72 y) and LDL-C ${\geq}$ 2.6 mmol/L. To determine whether plasma HDL-C concentrations were associated with dietary components, circulating atherogenic particles, and other risk factors for CVD, we divided the subjects into two groups: high HDL-C (H-HDL) (${\geq}$ 1.3 mmol/L, n=32) and low HDL-C (L-HDL) (< 1.3 mmol/L, n=57). Plasma lipids, insulin, adiponectin, apolipoproteins, oxidized LDL, Lipoprotein(a), and lipoprotein size and subfractions were measured, and 3-d dietary records were used to assess macronutrient intake. Women with L-HDL had higher sugar intake and glycemic load (P< 0.05), higher plasma insulin (P< 0.01), lower adiponectin (P< 0.05), and higher numbers of atherogenic lipoproteins such as large VLDL (P < 0.01) and small LDL (P<0.001) than the H-HDL group. Women with L-HDL also had larger VLDL and both smaller LDL and HDL particle diameters (P<0.001). HDL-C was positively correlated with LDL size (r=0.691, P<0.0001) and HDL size (r=0.606, P<0.001), and inversely correlated with VLDL size (r=-0.327, P<0.01). We concluded that L-HDL could be used as a marker for increased numbers of circulating atherogenic lipoproteins as well as increased insulin resistance in women who are already at risk for CVD.

• BMB Reports
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• v.42 no.9
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• pp.605-610
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• 2009

Plasma high-density lipoprotein cholesterol (HDL-C) levels are inversely correlated with the risk of cardiovascular disease, and are known to increase with repetitive exercise. In the current study, HDL fractions from athletes' sera were isolated and compared as a function of the type of sport (runners [n = 10], throwers [n = 10], wrestlers [n = 10], and weight lifters [n = 8]), and as an age- and gender-matched reference group (n = 14). Among athletes, HDL from runners had the strongest antioxidant activity. Immunodetection showed that runners and wrestlers had the highest levels of apoA-I and lowest levels of apoA-II in their HDL. Electron microscopy also revealed that HDL2 of runners and wrestlers were the largest in size. In conclusion, although all athlete groups had significantly better serum lipid/lipoprotein profiles than the reference group, runners and wrestlers had the most desirable lipoprotein function and structure, including antioxidant activity, HDL-associated enzyme activities and increased particle size.

• Molecules and Cells
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• v.25 no.3
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• pp.347-351
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• 2008

Several lines of evidence indicate that the oxidative modification of protein and the subsequent accumulation of the modified proteins have been found in cells during aging, oxidative stress, and in various pathological states including premature diseases, muscular dystrophy, rheumatoid arthritis, and atherosclerosis. The important agents that give rise to the modification of a protein may be represented by reactive aldehydic intermediates, such as ketoaldehydes, 2-alkenals and 4-hydroxy-2-alkenals. These reactive aldehydes are considered important mediators of cell damage due to their ability to covalently modify biomolecules, which can disrupt important cellular functions and can cause mutations. Furthermore, the adduction of aldehydes to apolipoprotein B in low-density lipoproteins (LDL) has been strongly implicated in the mechanism by which LDL is converted to an atherogenic form that is taken up by macrophages, leading to the formation of foam cells. During the search for an endogenous inducer of cyclooxygenase-2 (COX-2), an inducible isoform responsible for high levels of prostaglandin production during inflammation and immune responses, 4-hydroxy-2-noennal (HNE), one of the most representative lipid peroxidation product, has been identified as the potential inducer of COX-2. In addition, the following study on the molecular mechanism of the COX-2 induction by HNE has unequivocally established that a serum component, which is eventually identified to be denatured LDL, is essential for COX-2 induction. Here I review current understanding of the mechanisms by which HNE in cooperation with the serum component activates gene expression of COX-2.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.1-25
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• 1996

The pathogenesis of atherosclerosis can not be summarized as a single process. Lipid infiltration hypothesis and endothelial injury hypothesis have been proposed and investigated. Recent developments show that there are many points of potential interactions between them and that they can actually be regarded as two phases of a single, unifying hypothesis. Among the many risk factors of atherosclerosis, plasma homocysteine and lipoprotein(a) draw a considerable interest because they are independent indicators of atherogenicity. Triglyceride (TG)-rich lipoproteins (chylomicron and VLDL) are not considered to be atherogenic but they are related to the metabolism of HDL cholesterol and indirectly related to coronary heart disease (CHD). LDL can of itself be atherogenic but the oxidative products of this lipoprotein are more detrimental. HDL cholesterol has been considered to be a favorable cholesterol. The so-called 'causalist view' claims that HDL traps excess cholesterol from cellular membranes and transfers it to TG-rich lipoproteins that are subsequently removed by hepatic receptors. In the so-called 'noncausalist view', HDL does not interfere directly with cholesterol deposition in the arterial wall but instead reflects he metabolism of TG-rich lipoproteins and their conversion to atherogenic remnants. Approximately 70-80% of the human population shows an effective feedback control mechanism in cholesterol homeostasis. Type of dietary fat has a significant effect on the lipoprotein cholesterol metabolism and atherosclerosis. Generally, saturated fatty acids elevate and PUFA lower serum cholesterol, whereas MUFA have no specific effect. EPA and DHA inhibit the synthesis of TG, VLDL and LDL, and may have favourable effects on some of the risk factors. Phospholipids, particularly lecithin, have an antiatherosclerotic effect. Essential phospholipids (EPL) may enhance the formation of polyunsaturated cholesteryl ester (CE) which is less sclerotic and more easily dispersed via enhanced hydrolysis of CE in the arterial wall. Also, neutral fecal steroid elimination may be enhanced and cholesterol absorption reduced following EPL treatment. Antioxidants protect lipoproteins from oxidation, and cells from the injury of toxic, oxidized LDL. The rationale for lowering of serum cholesterol is the strong association between elevation of plasma or serum cholesterol and CHD. Cholesterol-lowing, especially LDL cholesterol, to the target level could be achieved using diet and combination of drug therapy. Information on the link between cholesterol and CHD has decreased egg consumption by 16-25%. Some clinical studies have indicated that dietary cholesterol and egg have a significant hypercholesterolemic effect, while others have indicated no effect. These studies differed in the use of purified cholesterol or cholesterol in eggs, in the range of baseline and challenge cholesterol levels, in the quality and quantity of concomitant dietary fat, in the study population demographics and initial serum cholesterol levels, and clinical settings. Cholesterol content of eggs varies to a certain extent depending on the age, breed and diet of hens. However, egg yolk cholesterol level is very resistant to change because of the particular mechanism involved in yolk formation. Egg yolk contains a factor of factors responsible for accelerated cholesterol metabolism and excretion compared with crystalline cholesterol. One of these factors could be egg lecithin. Egg lecithin may not be as effective as soybean lecithin in lowering serum cholesterol level due probably to the differences of fatty acid composition. However, egg lecithin may have positive effects in hypercholesterolemia by increasing serum HDL level and excretion of fecal cholesterol. The association of serum cholesterol with egg consumption has been widely studied. When the basal or control diet contained little or no cholesterol, consumption of 1 or 2 eggs daily increased the concentration of plasma cholesterol, whereas that of the normolipemic persons on a normal diet was not significantly influenced by consuming 2 to 3 eggs daily. At higher levels of egg consumption, the concentration of HDL tends to increase as well as LDL. There exist hyper-and hypo-responders to dietary (egg) cholesterol. Identifying individuals in both categories would be useful from the point of view of nutrition guidelines. Dietary modification of fatty acid composition has been pursued as a viable method of modifying fat composition of eggs and adding value to eggs. In many cases beneficial effects of PUFA enriched eggs have been demonstrated. Generally, consumption of n-3 fatty acids enriched eggs lowered the concentration of plasma TG and total cholesterol compared to the consumption of regular eggs. Due to the highly oxidative nature of PUFA, stability of this fat is essential. The implication of hepatic lipid accumulation which was observed in hens fed on fish oils should be explored. Nutritional manipulations, such as supplementation with iodine, inhibitors of cholesterol biosynthesis, garlic products, amino acids and high fibre ingredients, have met a limited success in lowering egg cholesterol.

• Nutritional Sciences
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• v.6 no.4
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• pp.229-231
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• 2003

New biochemical and genetic markers will be required to be more successful in the prevention of coronary heart disease. Postprandial lipid metabolism has received considerable attention since it was shown that postprandial triglyceride-rich lipoproteins are independently involved in the development of atherosclerosis. Multiple genes and environmental factors work in concert to alter these lipid. In this paper, postprandial lipemia, genetic variation and cardiovascular risk will be reviewed.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.833-834
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• 2001

A membrane immuno-chromatographic system that selectively separated plasma lipoproteins and generated a signal in proportion to the concentration of cholesterol within high-density lipoprotein (HDL) was investigated as a point-of-care device for the prognosis of coronary heart disease.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.201-204
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• 2003

Plasma lipoproteins transporting cholesterol through blood vessels are divided into three major classes, VLDL, LDL, and HDL. The ratio of HDL cholesterol over the total can be used as an indicator for prognosis of coronary artery diseases. In this study, we have developed two analytical systems for %HDL cholesterol with different flow modes toward gravity and analyzed them for their characteristics and performances.