• 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.

• Korean Journal of Pharmacognosy
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• v.27 no.3
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• pp.267-273
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• 1996

The methanol extract of Taraxacum coreanum Nakai (Compositae) was examined on the in vitro oxidation of human low density lipoprotein (LDL). It is well known that LDL oxidation induced artherosclerosis, if we can protect LDL oxidation process, excess plasma lipoprotein accumulation into the arterial lesion prone areas can be blocked. The methanol extract was treated with oxidized LDL which was incubated with $16\;{\mu}M$ $Cu^{2+}$ for metal catalyzed oxidation and TBA value, mobility on agarose gel and formation of conjugated diene and change of vitamin E were determined for the evaluation. The extract showed antioxidative effect at concentration $200\;{\mu}g/ml$ on LDL oxidation.

• 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 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.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.366-371
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• 2000

The aim of this study was to investigate the efficiency of the pentagalloic acid compound in inhibiting the metal ions and cell lines that mediate in low density lipoprotein (LDL) oxidation. Pentagalloic acid prolonged the lag time preceeding the onset of conjugated diene formation. In chemically induced LDL oxidation by Cu$^2$(sup)+ plus hydrogen peroxide or peroxyl radical generated by 2, 2-azo-vis (2-amidino propane) hydrochloride (AAPH), pentagalloic acid inhibited LDL oxidation as monitored by measuring the thiobarbituric acid reactive substances(TBARS), malondialdehyde(MDA), and gel electrophoretic mobility. The physiological relevance of the antioxidative activity was validated at the cellular level where pentagalloic acid inhibited mouse macrophage J774 and endothelial cell-mediated LDL oxidation. When compared with several other antioxidants, pentagalloic acid showed a much higher ability than naturally occuring antioxidants, ${\alpha}$-tocopherol and ascorbic acid, and the synthetic antioxidant, probucol.

• 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.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.

• YAKHAK HOEJI
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• v.45 no.5
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• pp.529-536
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• 2001

The root of Astragalus membranaceus Bunge (Leguminosae), which has been used for the treatment of hypertension, chronic hepatitis, duodenal ulcers, chronic nephritis and promotion of immunity in folk remedies. Several lines of evidence indicate that oxidative modification of low-density lipoprotein (Ox-LDL) may play an important role in atherogenesis. Hence, the role of antioxidants in the prevention of LDL oxidation needs to be determined. To investigate the antioxidant activity. we determined the MeOH ex. and fractions of Astragali Radix on the inhibition of LDL oxidation. The CH$_2$C1$_2$ and EtOAc orations inhibited the oxidative modification of LDL by a decrease in the lipid peroxide content and the electrophoretic mobility of LDL. Calycosin-7-0-$\beta$-D -glucoside which was isolated from EtOAc fraction inhibits the oxidative modification of LDL.

• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.286-292
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• 1997

This study was undertaken to evaluate an antioxidative activity of silymarin and silybin obtained from Silybum marianum against oxidation of human low density lipoprotein (LDL). The electrophoretic mobility observed apparently was higher phase for LDL oxidized by macrophages compared to native LDL. Silymarin and silybin inhibited the copper-catalysed oxidation of human LDL in a dose-dependent manner. Silymarin and silybin at the concentration of 50 $\mu$M/ml also inhibited the copper catalysed oxidation of LDL induced by the cell J774 and macrophages. LDL reisolated from the cell incubation in the presence of silymarin or silybin was degraded at rates similar with native LDL. Silymarin or silybin found to be potential inhibitors against oxidation of $^{125}$I-LDL by macrophages and endothelial cells.

• 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.