• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.1163-1175
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• 2023

Cholesterol is prone to oxidation, which results in the formation of cholesterol oxidation products (COPs). This occurs because it is a monounsaturated lipid with a double bond on C-5 position. Cholesterol in foods is mostly non-enzymatically oxidized by reactive oxygen species (ROS)-mediated auto-oxidative reaction. The COPs are found in many common foods of animal-origin and are formed during their manufacture process. The formation of COPs is mainly related to the temperature and the heating time the food is processed, storage condition, light exposure and level of activator present such as free radical. The level of COPs in processed foods could reach up to 1-10 % of the total cholesterol depending on the foods. The most predominant COPs in foods including meat, eggs, dairy products as well as other foods of animal origin were 7-ketocholesterol, 7 α-hydroxycholesterol (7α-OH), 7β-hydroxycholesterol (7β-OH), 5,6α-epoxycholesterol (5,6α-EP), 5,6β-epoxycholesterol (5,6β-EP), 25-hydoxycholesterol (25-OH), 20-hydroxycholesterol (20-OH) and cholestanetriol (triol). They are mainly formed non-enzymatically by cholesterol autoxidation. The COPs are known to be potentially more hazardous to human health than pure cholesterol. The procedure to block cholesterol oxidation in foods should be similar to that of lipid oxidation inhibition since both cholesterol and lipid oxidation go through the same free radical mechanism. The formation of COPs in foods can be stopped by decreasing heating time and temperature, controlling storage condition as well as adding antioxidants into food products. This review aims to present, discuss and respond to articles and studies published on the topics of the formation and inhibition of COPs in foods and key factors that might affect cholesterol oxidation. This review may be used as a basic guide to control the formation of COPs in the food industry.

• Nutrition Research and Practice
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• v.18 no.2
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• pp.194-209
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• 2024

BACKGROUND/OBJECTIVES: High levels of plasma low-density lipoprotein (LDL) cholesterol are an important determinant of atherosclerotic lesion formation. The disruption of cholesterol efflux or reverse cholesterol transport (RCT) in peripheral tissues and macrophages may promote atherogenesis. The aim of the current study was to examine whether bioactive ellagic acid, a functional food component, improved RCT functionality and high-density lipoprotein (HDL) function in diet-induced atherogenesis of apolipoproteins E (apoE) knockout (KO) mice. MATERIALS/METHODS: Wild type mice and apoE KO mice were fed a high-cholesterol Paigen diet for 10 weeks to induce hypercholesterolemia and atherosclerosis, and concomitantly received 10 mg/kg ellagic acid via gavage. RESULTS: Supplying ellagic acid enhanced induction of apoE and ATP-binding cassette (ABC) transporter G1 in oxidized LDL-exposed macrophages, facilitating cholesterol efflux associated with RCT. Oral administration of ellagic acid to apoE KO mice fed on Paigen diet improved hypercholesterolemia with reduced atherogenic index. This compound enhanced the expression of ABC transporters in peritoneal macrophages isolated from apoE KO mice fed on Paigen diet, indicating increased cholesterol efflux. Plasma levels of cholesterol ester transport protein and phospholipid transport protein involved in RCT were elevated in mice lack of apoE gene, which was substantially reduced by supplementing ellagic acid to Paigen diet-fed mice. In addition, ellagic acid attenuated hepatic lipid accumulation in apoE KO mice, evidenced by staining of hematoxylin and eosin and oil red O. Furthermore, the supplementation of 10 mg/kg ellagic acid favorably influenced the transcriptional levels of hepatic LDL receptor and scavenger receptor-B1 in Paigen diet-fed apoE KO mice. CONCLUSION: Ellagic acid may be an athero-protective dietary compound encumbering diet-induced atherogenesis though improving the RCT functionality.

• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.41-49
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• 1989

This study was carried out to study influence of antioxidants on serum and tissue of rats fed with thermally oxidized oil. The experimental animals used 30male rats of sprague-dawley weighting $150{\pm}25g$. They are divided into 5 groups and fed to experimental diets which are composed of 15％ thermally oxidized oil in addition to ascorbic acid, Vitamin E, Ethylendintrioteraaceticacid(EDTA) and none added oxidized oil by heat and fresh soybean oil group. Thermally oxidized oil was prepared from the soybean oil by heating at $180^{\circ}C$ for 30 hours. After feeding for 4 weeks, the result are as follows; 1. Body weight gain were lower B diet group than A diet group. 2. Total cholesterol levels in serum of all experimental diet groups except B diet group were higher than that of A diet group. 3. HDL-cholesterol levels of all experimental diet groups except E diet group were lower than that of A diet group. 4. The activities of GOT, GPT in serum of all experimental diet groups except B diet group and D diet group were higher than that of A diet group. 5. Vitamin E levels in serum of E diet group were highest than that of all experimental diet groups, and Vitamin E levels in liver of A diet group were highest than that of all experimental diet groups. 6. Lipid peroxide in Serum were highest B diet group than that of all experimental diet groups and the other experimental diet group significantly lower than that of the A diet group. 7. Lipid peroxide in liver of all experimental diet group except E diet group were significantly higher than that A diet group and lipid peroxide in kidney of all experimental diet group except B diet group were lower than that of A diet group. Four these results, as Vitamin C, Vitamin E, and EDTA added diets have effect of thermally oil by antioxidants, it could be suggested that thermally soybean oil diet has required to add antioxidant because it has not sufficient Vitamin E for antioxidant and intake and overtake level of thermally soybean oil diet should be studied to go ahead.

• The Journal of Korean Medicine
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• v.23 no.2
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• pp.164-179
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• 2002

Object: Death rate due to hypertension, atherosclerosis, ischemic heart disease and cerebral infarction induced by Westernized diet and increased average life span is on the rise. Decrease in blood circulation, activation of thrombus generation and intravascular lipid accumulation, cited as the principal causes of the above mentioned diseases in recent studies, result in circulatory disturbance and blood vessel obstruction leading to ischemic cell death of heart, brain and peripheral vessels. Method: We investigated the biochemical changes in microvascular permeability, aggregation of platelet and the intravascular lipid accumulation in induced-diabetic rat using Streptozotocin. We also studied the effects of Woohwangcheongsirn-won after oral administration on blood circulation, platelet function and lipid metabolism. The results are as follows: I. Woohwangcheongsim-won increased blood circulation in microvessels. 2. Woohwangcheongsim-won increased the reduced erythrocyte deformability in diabetes. 3. Woohwangcheongsim-won induced the reduction of contents of 2, 3-DPG, but failed to affect the reduced contents of ATP in erythrocyte in diabetes. 4. Woohwangcheongsim-won reduced the activity of Ca/sup 2+/-ATPase in the membrane of erythrocyte. 5. Woohwangcheongsim-won reduced the platelet aggregation evoked by platelet agglutinin factor. 6. Woohwangcheongsim-won reduced the production of platelet-derived granules. 7. Woohwangcheongsim-won reduced the production of metabolites of arachidonic acid in diabetes, and also reduced the production of increased thromboxane B2. 8. Woohwangcheongsim-won reduced the synthesis of oxidized LDL-cholesterol. In conclusion, Woohwangcheongsim-won enhanced blood circulation in microvesseles, erythrocyte deformability and inhibited the increased platelet aggregation and the synthesis of oxidized LDL-cholesterol in diabetes. Therefore Woohwangcheongsim-won is believed to positively affect blood circulation (J Korean Oriental Med 2002;23(2):164-179)

• Korean Journal of Acupuncture
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• v.26 no.2
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• pp.109-126
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• 2009

Objectives: To investigate the effects of Chrysanthemum indicum L. pharmacopuncture on lipids, antioxidant capacity and anti-inflammation in rats fed high-fat diet. Methods: Hyperlipidemic rats induced by high-fat diet were divided into 5 groups: no treatment control (normal, n=8), high-fat diet only control (control, n=8), high-fat diet and Chrysanthemum indicum L. pharmacopuncture at CV4 group (TI, n=8), high-fat diet and Chrysanthemum indicum L. pharmacopuncture at CV17 group (TII, n=8), and high-fat diet and Chrysanthemum indicum L. pharmacopuncture at EX-HN3 group (TIII, n=8). They were given pharmacopuncture accordingly every other day for two weeks followed by analyses of lowering lipids effects, oxidative capacity and anti-inflammatory effects. Results: Compared with the control, pharmacopuncture groups showed significantly decreased plasma total cholesterol (TC), liver thiobarbituric acid reactive substance (TBARS), catalase, glutathione peroxidase, neutrophils, monocytes, plasma and liver IL-$1{\beta}$, and plasma and liver IL-6. In other parameters including plasma and liver triglyceride, liver TC, LDL-cholesterol, HDL-cholesterol, liver TBARS, supraoxide dismutase, total protein, albumin, blood cell analysis, plasma and liver TNF-$\alpha$, and IL-10, there was no significant difference between control and pharmacopuncture groups. No clear acupoint-specificity was observed. Conclusions: Chrysanthemum indicum L. pharmacopuncture may improve control of hyperlipidemia.

• The Korean Journal of Food And Nutrition
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• v.22 no.4
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• pp.517-525
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• 2009

This study investigated the effects of Angelica keiskei Koidzumi and turmeric extract supplementation(ATE) on blood lipids, antioxidant and inflammatory markers in 35 hypercholesterolemic Korean adults with high blood cholesterol levels (serum total cholesterol$\geq200mg/d{\ell}$ or LDL-cholesterol$\geq130mg/d{\ell}$). They received ATE(n=21, 14 females and 7 males) or placebo(control group, n=14, 11 females and 3 males) for 4 weeks. There was no significant change in serum total cholesterol, LDL-cholesterol and HDL-cholesterol levels after ATE supplementation in the both groups. However, the LDLcholesterol: HDL-cholesterol ratio(LPH) was significantly decreased and both serum prostagrandin E2(PGE2) levels were significantly decreased in those receiving ATE. No significant changes were evident in interleukin(IL)-$1\beta$, IL-6, IL-8, 8-isoprostane, malondialehyde, total antioxidant capacity and oxidized-LDL. These results suggest that complex extract of Angelica keiske and turmeric has the potential to decrease cardiovascular risk by reducing LPH and inflammatory mediator $PGE_2$ in hypercholesterolemic adults.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.205-209
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• 1999

Cholesterol plays an important role in various physiological responses and membrane stability. To investigate the effect of cholesterol in liposome on the stability of encapsulated ascorbic acid, the physico-chemical experiments using various amounts of cholesterol-containing liposomes were performed. The encapsulation efficiency of ascorbic acid was decreased with increasing cholesterol content in liposome, whereas size of liposome was increased. Furthermore, the stability of encapsulated ascorbic acid was increased with increasing the content of cholesterol. The stability was not affected by pH. Encapsulated ascorbic acid in liposome stored at $37^{\circ}C$ was rapidly oxidized compared to those stored at $4^{\circ}C$. These results suggest that cholesterol in liposome affects largely to the stability of encapsulated ascorbic acid.

• Nutrition Research and Practice
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• v.15 no.4
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• pp.431-443
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• 2021

BACKGROUND/OBJECTIVES: Nobiletin (NOB), a citrus flavonoid, is reported to have beneficial effects on cardiovascular and metabolic health. However, there is limited research investigating the effect of long-term supplementation with low-dose NOB on high-cholesterol diet (HCD)-induced hypercholesterolemia and non-obese nonalcoholic fatty liver disease (NAFLD). Therefore, we investigated the influence of NOB on hypercholesterolemia and NAFLD in HCD-fed mice. SUBJECTS/METHODS: C57BL/6J mice were fed a normal diet (ND) or HCD (35 kcal% fat, 1.25% cholesterol, 0.5% cholic acid) with or without NOB (0.02%) for 20 weeks. RESULTS: HCD feeding markedly reduced the final body weight compared to ND feeding, with no apparent energy intake differences. NOB supplementation suppressed HCD-induced weight loss without altering energy intake. Moreover, NOB significantly decreased the total cholesterol (TC) levels and the low-density lipoprotein (LDL)/very-LDL-cholesterol to TC ratio, and increased the high-density lipoprotein-cholesterol/TC ratio in plasma, compared to those for HCD feeding alone. The plasma levels of inflammatory and atherosclerosis markers (C-reactive protein, oxidized LDL, interleukin [IL]-1β, IL-6, and plasminogen activator inhibitor-1) were significantly lower, whereas those of anti-atherogenic adiponectin and paraoxonase were higher in the NOB-supplemented group than in the HCD control group. Furthermore, NOB significantly decreased liver weight, hepatic cholesterol and triglyceride contents, and lipid droplet accumulation by inhibiting messenger RNA expression of hepatic genes and activity levels of cholesterol synthesis-, esterification-, and fatty acid synthesis-associated enzymes, concomitantly enhancing fatty acid oxidation-related gene expression and enzyme activities. Dietary NOB supplementation may protect against hypercholesterolemia and NAFLD via regulation of hepatic lipid metabolism in HCD-fed mice; these effects are associated with the amelioration of inflammation and reductions in the levels of atherosclerosis-associated cardiovascular markers. CONCLUSIONS: The present study suggests that NOB may serve as a potential therapeutic agent for the treatment of HCD-induced hypercholesterolemia and NAFLD.

• Korean Journal of Pharmacognosy
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• v.34 no.1 s.132
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• pp.100-108
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• 2003

The regulation of plasma lipid level, particularly LDL cholesterol, represents the focus of current therapy for atherosclerosis. And $Lp-PLA_2$ is able to hydrolyse oxidized phosphatidylcholine within LDL into lyso-PC and oxidized fatty acids. $Lp-PLA_2$ is a potential biomarker of coronary heart disease and plays an important proinflammatory role in the progression of atherosclerosis. We investigated the inhibitory effects of methanol extracts of 224 natural plants on $Lp-PLA_2$ activity. Seven kinds of methanol extracts of tested plants showed above 50% inhibitory effect with the concentration of $100\;{\mu}g/ml$. The concentrated aqueous suspensions of each methanol extract were partitioned with n-hexane, $CHCl_3$, and EtOAc. Among them, EtOAc extracts of Astilbe chinensis var. davidii (root) and Pourthiaea villosa var. brunnea (leaf) significantly inhibited $Lp-PLA_2$ activity at the same concentration.

• Journal of Life Science
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• v.5 no.2
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• pp.1-1
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• 1995

Casein or soybean protein was subjected to there action with caffeic acidtyrosinase system at 30-35$\circ$C, pH 6.8 with aeration for 5hr. The resulting brown proteins were washed with acetone until the washings were on longer colored. However, modified protein still retained a light brown. The effects of the modified proteins and brown compounds on male Wistar strain rats were studied by pair-feeding of a cholesterol-free diet for 14days. Significant decrease in protein digestibility for the rats fed with the modified proteins were observed. Weight gain and protein digestibility were not influenced by feeding brown compounds, but the feeding of brown compound from casein caused an enlargement of caecum. The concentrations of serum cholesterol and triglyceride in the rats fed with modified proteins and brown compounds were mostly unchanged against the rats fed with untreated proteins. These results suggest that the decrease in protein digestibility induced by enzymic browning-reaction did not cause the decrease in concentration of serum cholesterol.