• 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.

• 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 Nutrition and Health
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• v.26 no.7
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• pp.819-828
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• 1993

The reaction of lecithin cholesterol acyltransferase(LCAT) and cholesteryl ester transfer protein (CETP) are important in cholesterol esterification and transfer for the reverse cholesterol transport(RCT) system. The purpose of this study were to assess the effects of fatty acid unsaturation on RCT system. After 12 female human subjects consumed a prescribed high saturated fat diet prior to the period, two groups of six subjects were provided with a high PUFA(corn oil) or a high SFA(butter) as major fats in a 40 en % fat diet. Butter feeding increased plasma total-(34%), esterified-(96%), HDL_3$-(23%), LDL-(20%), and VLDL plus LDL(35%) cholesterol while corn oil feeding decreased esterified-(25%), LDL(15%) cholesterol and TG(27%). There were significant differences of fats on total-(p=0.0001), esterified-(p=0.0001), total HDL-(p=0.005), $HDL_2$-(p=0.01)and LDL-(p=0.0001) cholesterol. LCAT activity did not change during the period but highly correlated to apo A-I in HDL which was increased in the corn oil group. The 2.5 fold increased CETP activity in the butter group during the period might be related to changes in plasma VLDL plus LDL cholesterol level which were increased in the butter group.

• 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.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.37-43
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• 2003

Engorgement of macrophages with cholesterol is the defining pathological characteristic of atherosclerotic plaques, the cause of most heart attacks and strokes. Activated human macrophages uptake low density lipoprotein (LDL) by the bulk-phase fluid, and aggregated LDL by patocytosis. After incorporation of LDL and aggregated LDL into macrophages, neutral cholesterol esterase is decreased and cholesterol efflux is also deceased, resulting that macrophages become foam cells.

• Journal of Life Science
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• v.18 no.1
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• pp.9-15
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• 2008

Sulfur containing compounds in garlic have all be used as one of the traditional folk medicine as well as food source. The present study was performed to investigate the antioxidative compounds of 1-methyl-1-cysteine, dimethyl trisulfide and 2-vinyl-4H-1,3-dithiin. The antioxidative activity of sulfur containing compounds on human LDL was investigated by monitoring a thiobarbituric acid substances (TBARS). Sulfur containing compounds inhibited on oxidation of LDL mediated by $CuSO_4$ and macrophages in dose dependent manner with almost completely inhibition at $80{\mu}g/ml$. Antioxidant activities of sulfur containing compounds on LDL oxidation were 2-vinyl-4H-1,3-dithiin, 1-methyl-1-cysteine, and dimethyl trisulfide in order. Inhibitory effects of sulfur containing compounds on oxidation of LDL mediated by $CuSO_4$ and macrophages were degraded at much greater rate than native LDL, the LDL oxidation process was arrested as shown by the lower conjugated dienes formation at the concentration of $60{\mu}g/ml$. Sulfur containing compounds in garlic revealed at high antioxidative activity at low physiological concentration for human LDL oxidation in vitro specially, it was indicated that the antioxidative activity of 3-viny l-4H-1,2-dithiin was higher than that of the other sulfur containing compounds.

• Journal of Nutrition and Health
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• v.24 no.4
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• pp.378-392
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• 1991

A series of studies in monkeys and hamsters, and reevaluation of published human data, indicate that dietary saturated fatty acids exert a dissimilar metabolic impact on cholesterol metabolism. Myristic acid(14 : 0) appears to have a major cholesterol-raising effect by means of decreasing LDL receptor activity and by increasing the direct production of LDL (from sources other than VLDL-catabolism) Palmitic acid (16 : 0) appears neutral in most cases (plasma cholesterol<200mg/dl) or until the LDL receptor is down-regulated, as with high cholesterol intake or obesity. In such cases. the down-regulated LDL receptors coupled with an increased VLDL production (induced by 16 : 0 and 18 : 1) can divert VLDL remnants to LDL and expand the LDL pool. Furthermore. the cholesterolemic impact of any saturated fatty acid can be countered up to a saturable 'threshold' level by dietary linoleic acid (18 : 2) which up-regulates the LDL receptor. Once above this 'threshold' the major fatty acids (16 : 0, 18 : 0, 18 : 1, 18 : 2, 18 : 3) appear to exert an equal impact on the circulating cholesterol concentration.

• Korean Journal of Pharmacognosy
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• v.28 no.4
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• pp.275-279
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• 1997

Fruits of Arctium lappa L. (Compositae), which has been used as the antiinflammatory, detoxifying and diuretic agents in the folk remedies, was examined on the in vitro oxidation of human low density lipoprotein (LDL). Several lines of evidence indicate that oxidized LDL (Ox-LDL) may promote atherogenesis. Hence. The role of antioxidants in the prevention of LDL oxidation needs to be determined. The activity of fractions of Arctii Fructus treated with oxidized LDL which was incubated with $16\;{\mu}M$ of $Cu^{2+}$ for metal catalyzed oxidation was investigated. The BuOH fraction (4\;ppm) inhibited the oxidative modification of LDL as evidenced by a decrease in the lipid peroxide content (thiobarbituric acid reacting substances activity), the negative charge of LDL (electrophoretic mobility) and increase of the vitamine E content.

• Journal of Life Science
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• v.7 no.4
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• pp.289-296
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• 1997

Antioxidative activity of fraction extracted from cultivation of Aspergillus sp. A-5 against oxidation of human low density lipoprotein(LDL) was investigated. Fractions of Aspergillus sp. A-5 cultivation was sucessively purified with ethyl acetate and silica gel column chromatography. The concentration of fraction 4 inhibited Cu$^{2+}$-induced oxidation of LDL almost completely. Band 3 isolated by the further purification of fraction 4 was higher than that of same concentration of $\alpha$-tocopherol, BHA and BHT. The elcetrophoretic mobility of oxidized LDL by addition of Band 3 was faster than that of native LDL, but slower than that of oxidzed LDL. It is concluded that fraction of Aspergillus cultivation contained antioxidants with the capacity to inhibit oxidative modification of LDL.

• 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.