• Journal of Life Science
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• v.8 no.4
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• pp.353-359
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• 1998

This study was initiated to antioxidant activity of silybin on oxidation of human low density lipoproteins(LDL). Siltbin was extracted from Silybum marianum by the combination of fractionation and it was futher purified by silica gel column chromatography, and isolated active substances were identified silybin by IR, NMR and GC-MS. siltbin inhibited the ozidation of human low density lipoprotein(LDL) mediated by 5$^{\mu}$m CU $^{2+}$ ion in a dose dependent manner. LDL oxidation by congugated dines formation was completely inhibited by silybin at a concentration of 5$^{\mu}$M. The results provide a possibility that silybin might protect LDL against oxidation in atherosclerotic lessions.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.279-283
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• 2006

This study was conducted to examine the effect of polyphenols from safflower seed on HMG-CoA reductase (HMGR) activity, LDL oxidation and Apo A1 secretion from Hep3B cell. The safflower seed polyphenols were matairesinol (Iignan), enterolactone (lignan metabolite), acacetin (flavone) and serotonin derivative. In addition to safflower polyphenols, mevastatin, ${\alpha}-estradiol,\;{\alpha}-tocopherol$ and soy genistein were tested as reference compounds depending on the type of the test. HMGR source was liver microsome obtained from rat fed 2% cholestyramine for 10 days. Inhibition of HMGR activity was greater with mevastatin (53%) than safflower serotonin derivatives (45%), followed by genistein (35%), but was very small with matairesinol, enterolactone and acacetin. LDL oxidation induced by $CuSO_4$ was suppressed by all the test material used in the present study and in the order of safflower serotonin derivatives> matairesinol > ${\beta}-estradiol$ > genistein > acacetin > enterolactone. Apo A1 secretion from Hep3B cell was significantly stimulated by mevastatin, but moderately (p<0.1) by ${\beta}-estradiol$ and genistein as well as enterolactone. These results suggest that the safflower polyphenols improve body lipid status via inhibition of cholesterol synthesis and suppression of LDL oxidation.

• Journal of Life Science
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• v.22 no.12
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• pp.1712-1717
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• 2012

Oxidation of low density lipoprotein (LDL) plays an important role in the development and progression of atherosclerotic disease. In this study, human LDL was isolated and oxidized using $CuSO_4$ in the presence or absence of S-allylmercaptocysteine. Oxidative modification of the LDL fraction was monitored by both the appearance of thiobarbituric acid substances (TBARS), an increase in electrophoretic mobility, and conjugated diene formation. The addition of S-allylmercaptocysteine reduced lipid peroxide formation, indicating it to be an effective antioxidant. The inhibition of LDL oxidation by $5{\sim}20{\mu}g/ml$ S-allylmercaptocysteine occurred in a dose-dependent manner, as assessed by the TBARS assay. S-allylmercaptocysteine at $20{\mu}g/ml$ almost completely inhibited the $Cu^{2+}$ induced increases in electrophoretic mobility of LDL and almost completely inhibited conjugated diene formation. A more potent antioxidative activity was observed for S-allylmercaptocysteine than for either Vitamin C or $d{\ell}-{\alpha}$-tocopherol. Thus, S-allylmercaptocysteine aid in preventing the development and progression of atherosclerotic disease.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.313-319
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• 2000

A crucial and causative role in the pathogenesis of atherosclerosis is believed to be the oxidative modification of low density lipoprotein (LDL). The oxidation of LDL involves released free radical driven lipid peroxidation. Several lines of evidence support the role of oxidized LDL in atherogenesis. Epidemiologic studies have demonstrated an association between an increased intake of dietary antioxidant vitamins, such as vitamin E and vitamin C and reduced morbidity and mortality from coronary artery diseases. It is thus hypothesized that dietary antioxidants may help prevent the development and progression of atherosclerosis. The oxidation of LDL has been shown to be reduced by antioxidants, and, in animal models, improved antioxidants may offer possibilities for the prevention of atherosclerosis. The results of several on going long randomized intervention trials will provide valuahle information on the efficacy and safety of improved antioxidants in the prevention of atherosclerosis. This review a evaluates current literature involving antioxidants and vascular disease, with a particular focus on the potential mechanisms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.204-210
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• 2000

The antioxidative effects of solvent fractions of kimchi on LDL oxidatiojn in vitro as well as hypolipidemic effects of these fractions in rabbit fed atherogenic diet were studied. Methanol extract of deffated kimchi was fractionated sequentially with dichloromethane, ethylacetate, butanol and water. All solvent fractions of kimchi inhibited Cu2+-induced LDL oxidation. Among these fractions, the dicholoromethane fraction at the concentration of 25$\mu\textrm{g}$/mL showed the highest antioxidant effects against LDL oxidation in the aspect of inhibiting TBARS production by 28.03% or prolonged lag phase duration 2-fold compared to those of control. Based on the results from in vitro study, New Zealand White Rabbits grouped six each were fed for 8 weeks either basal diet containing 1% cholesterol or experimental diet containing dichloromethane, ethylacetate or water fraciton added to the basal diet. The amount of solvent fraction of kimchi added to the experimental diet was equivalent to 5% of freeze-dried kimchi. The hypolipidemic effects was observed from all experimental gropus, especially from dichloromethane fraction added group. The plasma and LDL cholesterol levels of this group were decreased by 49% and 47%, respectively while that of HDL increased by 91% compared to those of control. The calculated atherogenic index for the dichloromethane group was the lowest among groups. However, TG lowering effect of experimental group was not observed since solbent fraction of kimchi was used instead of freeze-dried kimchi. The TBARS concentration of LDL isolated from rabbit fed dichloromethane fraction was decreased 21% than that of control. These results indicate that active principles responsible for inhibiting LDL oxidation and lowering plasma cholesterol may present abundantly in dichloromethane fraction of kimchi.

• Journal of Society of Preventive Korean Medicine
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• v.16 no.2
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• pp.113-124
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• 2012

The oxidative modification of low density lipoprotein(LDL) has been implicated in the development of atherosclerosis. Oxidized LDL(oxLDL) is captured into macrophage and stimulates to form macrophage foam cell. And it can induce an inflammation and smooth muscle proliferation in atherosclerotic plaque. Objective : In this study, we aimed to investigate the effect of Bupleuri radix(SH) on the foam cell formation, a critical initiation stage of atherosclerosis. Methods : To achieve the goal, we examined the effect of SH on LDL oxidation, nitric oxide production in RAW264.7, and the effect of SH on cupuric sulfate-induced cytotoxicity, LDH release, and macrophage activity. Results : SH inhibited the formation of oxidized LDL from native LDL in RAW264.7 cell culture, and decreased the release of LDH from cupric sulfate-stimulated RAW264.7 cell. In other experiments, SH activated RAW264.7 cell, and prolonged the survival time, and inhibited foam cell formation induced by oxLDL in Raw 264.7 cells. Conclusion : These results showed that SH might prevent atherosclerosis by controlling the early stages of foam cell formation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.402-408
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• 1994

Human plasma low density lipoprotein (LDL) is the major factor of coronary heart disease.But recent studies suggest the normal LDL can be realdily oxidized by oxygen free radicals and not interact with LDL receptors.Lipoprotei particles consist of lipid and protein, and fatty acids are prone to oxidatioin.The fatty acid compositions of LDL from Koreans was compared with that of Westerners.From the results, the raio of unsaturated fatty acids of korean and Westerner approximately 30 and 70%, respectively.which means Westerners are more labile in the lipid oxidation of LDL than Koreams.Normal LDL was incubated with $CuSO_4$ in PBS to lead for the peroxidation of LDL, and it was tested by the detection of TBARS and free radicals.Then, ascorbate, ${\alpha}-tocopherol$ and hyaluronic acid were found to have effects of antioxidants on LDL oxidation.The amount of free radical increased as the extent of oxidation increased.The time course of free radical formation was similar to TBARS.Therefore, determination of free radical by Luminometer was much more convenient than that of TBARS.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.2
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• pp.189-195
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• 2013

This study was designed to analyze the effects of methanol extracts and solvent fractions of the young branch of Prunus persica on scavenging activity of ROS, RNS and inhibiting activity of oxidative modification in human LDL induced by copper ion or free radical generator. The scavenging capacities of the fractions on DPPH radical, superoxide radical, nitric oxide and peroxynitrite were exhibited the highest in ethylacetate fraction, followed by butanol fraction. In the copper-induced LDL oxidative modification system, the highest antioxidant activity was revealed in ethylacetate fraction, and butanol fraction exhibited a similar activity. However, solvent fractions of the young branch of Prunus persica showed a relatively low antioxidant activity in the AAPH-mediated LDL oxidation. In addition, ethylacetate and butanol fractions also inhibited the copper-mediated LDL oxidation in the REM assay, which was comparable to that of the positive controls, including EDTA, ascorbic acid and BHT. Futhermore, a content of total phenolics in these two fractions was higher than that of the other fractions. These results indicated that ethylacetate and butanol fractions of the young branch of Prunus persica were useful for the prevention of the free radical- or metal ion-induced oxidative damages.

• Korean Journal of Plant Resources
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• v.23 no.6
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• pp.519-525
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• 2010

Chlorogenic acid, formed of an ester of caffeic acid and quinic acid, which is naturally abundant in many plant species, was used as a model O-dihydoxy phenolic compound. In the previous study, we have reported that the isolated constituent from Apocynum venetum leaves has an inhibitory effect on $Cu^{2+}$-induced oxidative modification of low-density lipoprotein (LDL). Among them, chlorogenic acid showed the most potent anti-LDL oxidative activity than other compounds. For the reason, we investigated the inhibitory effect of the chlorogenic acid on $Cu^{2+}$-induced oxidative modification of LDL, monitored a lag time in the conjugated-diene formation and TBARS formation, and measured TNBS free amino acid group, and form cell formation in vitro system. The TBARS- and diene- formation were strongly inhibited by chlorogenic acid ($0{\sim}100\;{\mu}g/ml$) with dose dependent manner. On the other hand, TNBS reactive lysine amino groups on LDL oxidation were protected by chlorogenic acid- treated cell group. Therefore, chlorogenic acid inhibited to cholesterol accumulation in the isolated peritoneal macrophage.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.497-500
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• 2001

The purpose of this study was to investigate the extraction method and antioxidative activities of phenolic compounds from Korean red tail ginseng. Antioxidative activities of red tail ginseng were evaluated with its ability to donate hydrogen to DPPH, and to inhibit the oxidation of linoleic acid and LDL induced by $H_2O_2$ and $FeCl_2$, respectivly by measuring the MDA formation. Total phenolic compounds expressed as % caffeic acid were 0.80%, 0.12%, 0.06%, 0.03%, 0.01% when red tail ginseng was consecutively extracted with 60% ethanol for 5 times, most of the phenolic compounds was recovered in the extract obtained after 3 times of extraction. The extraction efficacy of 60% ethanol was superior to that of water in extraction phenolic compounds, and the efficacy did not change after evaporating the extract followed by dissolving with water. 60% ethanol extract of red tail ginseng had weak ability to donate hydrogen to DPPH. MDA determination showed the antioxidative effect with inhibition ratio of 72.23% on linoleic acid oxidation by addition of red tail ginseng extract at the concentration of 1,500 ppm. 22.52% of LDL oxidation was inhibited by addition of 250 ppm.