• Journal of Food Hygiene and Safety
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• v.16 no.4
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• pp.342-348
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• 2001

Growing evidence indicates that oxidized low density lipoprotein (LDL) may promote atherogenesis. Therefore, inhibition of LDL oxidation may impede this process. The effect of chitin sulfate on the susceptibility of human low density lipoprotein (LDL) to macrophages-induced oxidation was investigated by monitoring a thiobarbituric acid reactive substance (TBARS). Chitin sulfate inhibited LDL oxidation by macrophages in a dose dependent manner, with a 50~100$\mu$M, as assessed by TBAaS assay. Chitin sulfate, at 100 $\mu$M, almost completely inhibited the macrophage-induced increase in electrophoretic mobility of LDL. Also, chitin sulfate almost completely inhibit $O_2$￣ at concentration of 100 $\mu$M. These observations suggest that chitin sulfate might be an effective in prevention of atherosclerosis.

• 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.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.151-155
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• 2008

Oxidation of low density lipoprotein (LDL) is regarded to play an important role in the development of atherosclerosis. In the present study, salad vegetables with a remarkable DPPH radical-scavenging activity were extracted with methanol, and the methanol extracts were evaluated for the inhibition of $Cu^{2+}$-induced oxidation of human LDL. Separately, the amount of total phenolics was determined colorimetrically using Folin-Ciocalteu reagent. The vegetable extracts, expressing a strong inhibition of LDL oxidation ($IC_{50}$ values, <$100\;{\mu}g/mL$), were from angelica, dandelion, mustard leaf, and water spinach, which contained relatively high level of polyphenol content. Noteworthy, a highly positive correlation was observed between inhibition of LDL oxidation and amount of total polyphenol (p<0.01). Based on these results, it is suggested that salad vegetables, especially angelica, dandelion, and mustard leaf, may be used as easily accessible sources of natural antioxidants, especially in anti-atherosclerosis.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.254-259
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• 2011

Growing evidence indicates that oxidized low density lipoprotein (LDL) may promote atherogenesis. Therefore, inhibition of LDL oxidation may impede this process. The inhibitory effected on the susceptibility of human LDL to $Cu^{2+}$ or macrophages induced oxidation was investigated by monitoring thiobarbituric acid reactive substances(TBARS). Organosulfur compounds of garlic oil contains diallyldisulfide, diallyltrisulfide, diallyltetrasulfide, and diallyl pentasulfide in order. Garlic oil inhibited LDL oxidation by $Cu^{2+}$, or macrophages in a dose dependently, with a 20~60 ${\mu}g$, as increased TBARS assay. Garlic oil, at 60 ${\mu}M$, almost completely inhibited macrophages induced increase in electrophoretic mobility of LDL. When compared with several other antioxidants, probucol showed highest ability, and then garlic oil showed a much higher ability than natural occurring antioxidants, ${\alpha}$-tocopherol and ascorbic acid. The results suggested that garlic oil might play the inhibitory effects in the process of LDL oxidation.

• Journal of Life Science
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• v.9 no.2
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• pp.57-61
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• 1999

This study was designed to develope the antioxidative activity on oxidation of human low density lipoprotein(LDL) from marine microbials. Bacillus KS-96 producign antioxidant have been isolated and identified from seawater, Bacillus sp. KS-96. The optimal medium pH was 7.0 and incubation temperature was 30$^{\circ}C$. The antiosidant of potential substance produced extracellularly in the culture broth by Bacillus sp. KS-96 was obtained by elution of silica gel culumn chromatography with hexane, ethylacetate and water. The ethylacetate faction are shown at highest level of antioxidant activity using thiocyanate method among them. By IR, NMR, and GC/MS, antioxidant purified from ehtylacetate fraction was identified and named as 2,6-dimethoxyphenol. 2,6-dimethoxyphenol inhibited the metal mediated oxidation of human LDL at concentration of 50∼100 ${\mu}$g/mL in the presence of 5uM CuSO4 with macrophage or J774 cells.

• Journal of Life Science
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• v.14 no.1
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• pp.180-187
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• 2004

Crowing evidence indicates that oxidized low density lipoprotein (LDL) nay promote atherogenesis. Therefore, inhibition of LDL oxidation may impede this process. The effect of geraniin on the susceptibility of human low density lipoprotein (LDL) to macrophages-induced oxidation was investigated by monitoring a thiobarbiruric acid reactive substrance (TBARS). The antioxidative activity of geraniin was higher than that of $\alpha$-tocopherol on low density lipoprotein (LDL) oxidation by thiobarbituric acid reactive substance (TBARS). Geraniin inhibited the C $u^{2+}$ mediated oxidation of human LDL in a dose dependent manner at concentration of 50 and 100 $\mu\textrm{g}$/mL. Geraniin, almost completely inhibited the macrophages mediated LDL oxidation in electrophoretic mobility and conjugate diene of LDL oxidation. Also, geraniin almost completely inhibited 0$_2$$^{[-10]}$ at concentration of 100 $\mu\textrm{g}$/mL. The physiological relevance of the antioxidative activity was validated at the cellular level where geraniin inhibited endothelial cell mediated LDL oxidation, When compound with several other antioxidants geraniin showed a high activity equal to natural antioxidants, $\alpha$-tocopherol and ascorbic acid, and the synthetic antioxidant, protocol. These results indicate that geraniin might play a protective antioxidant effects on LDL, probably affecting both the structural properties of macrophage and endothelial cell for the LDL oxidation..

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.320-327
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• 1999

The flavonoids are one of the most numberous and widespread groups of natural consituents. The low molecular weight of benzo-${\gamma}$-pyrone derivative are ubiquitous in plants and are vegetables nuts, seeds, leaves, flowers, and bark. The flavonoids constitute of a large class of compounds ubiquitous in plants containing a number of phenolic hydroxyl groups attached to ring structures conferring the antioxidant activity. Epidemiologic studies suggest that the dietary intake of antioxidants constitutes a risk factor for vasclar disease indicating that oxidation may be important in the pathogenesis of human athero-sclerosis. Elevated plasma low density lipoprotein (LDL) cholesterol concentration are associated with accelerated atherosclerosis, LDL is oxidized by smooth muscle cells resulting in several chemicals and physical changes of LDL. Oxidized LDL is responsible for cholesterol loading of macrophages foam cells formation and atherogenesis. There have been insulficient tests of the protective effects of flavonoids against LDL oxidation to make definitive statements about their structure activity relationships. How-ever hydroxylation of the flavone uncleas can appears to be advantageous because polyhydroxylated aglycone flavonoids are potent inhibitor of LDL modification. This identification may lead to new and more effective antioxidant strategies for abrogating the atherosclerotic process the leading cause of death and disability in industrialized societies.

• Journal of Food Hygiene and Safety
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• v.13 no.1
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• pp.6-13
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• 1998

This study was carried out to investigate the antioxidative activity on oxidaton of human low density lipoprotein from marine microorganisms. Bacillus sp. RH-5 producing antioxidative activity have been isolated and identified from coast sea in Pusan. Bacillus sp. RH-5 produced at highest level of antioxidative activity in the medium of 1.0% glucose, 0.25% polypepton, 0.25% yeast extract, 0.01% $FeSO_4{\cdot}7H_2O$ and 50% sea water. The optimal medium pH, cultural temperature and shaking time for the highest production as the antioxidant were 7.0, $30^{\circ}C$ and 48 hr, respectively. The culture broth inhibited the copper catalyzed oxidation of human low density lipoprotein (LDL) at the concentration of 500 and $1,000\;\mu\textrm{g}/ml$ ethylacetate extracts in the presence of $5\;\mu\textrm{M}\;CuSo_4$. The electrophoretic mobility of the LDL oxidized in the presense of $5\;\mu\textrm{M}\;CuSo_4$ was higher than that of native LDL.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.800-807
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• 2001

This study was designed to investigate the antioxidative activity of a substance isolated from. The antioxidative activity of procyanidine was higher than that of dl-tocopherol and BHA on low-density lipoprotein (LDL) oxidation by thiobarbituric acid reactive substance (TBARS). Procyanidine inhibited the copper-mediated oxidation of human LDL in a dose dependent manner with almost complete inhibition at $60{\mu}g/mL$. Procyanidine at a concentration of $80{\mu}g/mL$ in hibited oxidation of LDL induced by J774. LDL oxidized by copper-mediated or cell-induced oxidation was degraded at a much greater rate than native LDL. These results suggested the importance of further research to procyanidine in the investigation of atherosclerosis and free radical-induced injury.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.3
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• pp.362-370
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• 1995

Human plasma low density lipoprotein(LDL) is the main carrier for cholesterol, and recent studies suggest the normal LDL can be readily oxidized by free radical and not interact with LDL receptor. Lipoprotein pariticles are consisted of lipid andprotein, and fatty acids of lipoproteins are prone to oxidation. LDL particles readily undergo oxidative modification by copper. From the results, oxidized LDL altered its biological properties. A marked increase in the electrophoretic mobility of LDl on agarose gel indicated that negative surface charge of the LDL particles was increased. Also, the results from the HPLC showed that oxidized LDL was degraded into several polypeptides nonenzymatically. Degradation tests which measured the amount of 5-IAF labelled oxidized LDL were carried out by monocyte and hepatocyte cell culture. Hepatocyte cell culture of modified LDL did not show consistent pattern. However, binding rate of modified LDL with HMDM(human monocyte derived macrophage) was enhanced with oxidation, but was retarded by addition of antioxidants(hyaluronic acid, vitamin A, vitamin E). Also comparisons of oxidized-LDL, acetyl-LDL and MDA-LDL showed significant differences in the chemical properteis and binding affinity to HMDM. Thus, modificaition of normal LDL altered its biological properties.