• 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.

• Journal of Food Hygiene and Safety
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• v.14 no.2
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• pp.153-159
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• 1999

This study was undertaken to evaluate antioxidative activities of substances isolated from marine resources against human low density lipoprotein (LDL). Methanol-water extract(80 : 20, v/v) of Sargassum ringgoldianum had the highest antioxidant activity and the active substance was purified by silica gel column chromatography by eluting chlorform : methanol mixture (80 : 20 v/v). The active fraction was seperated to several spots on the TLC in chlorofrom : methanol (10 : 1, v/v) mixture. Antioxidative activity of band 4 of fraction 2 on TLC was highest than that of $\alpha$-tocopherol against human LDL oxidation by the method of thiobarbituric acid reactive substance (TBARS). The band 4 of fraction 2 inhibited the copper mediated oxidation of human LDL with almost completely at 1 or 2 mg/ml.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.138-146
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• 2004

This study was designed to investigate antioxidative activity of substances isolated from 25 kinds of useful plants resources toward free radical and human low density lipoprotein(LDL). Methanol extracts of Oenothers odorate had the highest antioxidative activity similar with ${\alpha}$-tocopherol. Methanol extracts of Oenothers odorate was extracted again by the ethylacetate. The ethylacetate soluble acidic fraction obtained from methanol extract of Oenothers odorate showed highest activity toward human LDL. Each fraction was purified through Sepadex LH-20 chromatography by elution of chloroform-methanol mixture (90:10 v/v). Fraction, F-2 obtained from Oenothers odorate showed at highest levels of electron donating activity. Fraction, F-2 was identified as 3,4-dihydroxybenzoic acid and 3-hydroxycinnamic acid.

• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.1-8
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• 1997

This study was performed to evaluate the antioxidant activity of silymarin against human low density lipoproteins(LDL) oxidation. Silymarin extracted from Silybum marianum was successively purified with solvent fractionation and followed by silica gel column chromatography. The active substances were separated by HPLC and the isolated active substances, silymarin were identified by IR, NMR, GC-MS as silymarin. Silymarin inhibited at the 5 $\mu$M Cu2+-mediated oxidation of human low density lipoprotein (LDL) in a dose dependent manner. Silymarin completely inhibited LDL oxidation at 50 $\mu\textrm{g}$/$m\ell$ concentration. These findings suggest that silymarin may protect LDL against oxidation in atherosclerotic lessions.

• Journal of Nutrition and Health
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• v.19 no.5
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• pp.296-303
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• 1986

Rat lipoprotein-deficient plasma possessed a lipid tramsfer inhibitory activity when it was added to purified human plasma lipid transfer protien, while it lacked a lipid transfer activity. Incubation of whole rat plasma with partially purified human lipid transfer protein resulted in big changes in lipid distribution of rat plasma lipoproteins. There w was a 4-fold increase in cholesteryl ester(CE) and 4 47 % reduction in triglyceride(TG) in very low density lipoproteins after 2싹lour incubation. In high density lipoprotein $2(HDL_2)$ there was a 9­fold increase in TG and 33 % reduction in CEo HDL3 had 82 % reduction in CE. The result indi­c cates that the absence of the lipid transfer activity in rat plasma can be ascribed not to the inability of rat lipoproteins to serve as substrates but to the lack of 야Ie lipid transfer protein in rat plasma. Th­e erefore, species differences in lipid transfer betwe­e en lipoproteins should be taken into consideration to interpret results of studies on lipoprotein m.eta­b bolism using rats.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.44.2-44.2
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• 2007

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• Journal of Life Science
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• v.17 no.10
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• pp.1330-1335
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• 2007

This study was developed to assess the antioxidative activity of aged black garlic extract on lipid peroxidation and low density lipoprotein (LDL). Antioxidative activity of aged black garlic extract on human low density lipoprotein (LDL) was investigated by monitoring a barbituric acid reactive substance (TBARS). Electron donating ability (EDA) of aged black garlic, ethanol extract was higher than that alliin and water extract. Aged black garlic water and ethanol extracts inhibited the $Cu^{2+}$ mediated oxidation of human LDL in a dose dependent manner at concentration of 10 and $20\;{\mu}g/ml$. Ethanol extract and water extract of aged black garlic almost completely inhibited J774 mediated LDL oxidation in electrophoretic mobility and conjugated diene. These results indicate that aged black garlic might play a protective antioxidant effects on LDL, probably affecting the structural properties for the 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.

• 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 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.