• 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.

• KSBB Journal
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• v.15 no.2
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• pp.156-161
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• 2000

This study was designed to investigate the antioxidative activity on oxidation of human low density lipoprotein(LDL) of band 2 fractionated from culture broth of Streptomyces sp. BH-405. Antioxidative activity of band 2 obtained from fractionation of BH-405 culture purification was measured against $Cu^{2+}$ mediated human LDL oxidation by thiobarbituric acid reactive substance. $CuSO_4$ mediated oxidation of LDL was degraded at a much higher rate than native LDL. Band 2 at a concentration of 100 or 200 !lg/mL inhibited the oxidation of LDL induced by $CuSO_4$, The formation of conjugated dienes induced in the presence of 5 !1M CuS04 of the mouse macrophage and J744. The electrophoretic mobility of the LDL in addition of $200\mu\textrm{g}$ band 2 in the presence of $5\mu\textrm{m}$ $CuSO_4$ was lower than that of native LDL. LDL modified by copper mediated or cell mediated uptake was degraded by macrophage at much greater than native LDL, and band 2 was found as potential inhibitor of modification of 125I-labelled LDL by macrophage. phage.

• 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.

• Journal of Life Science
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• v.9 no.1
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• pp.99-105
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• 1999

The aims of this studies were carried out to investigate the antioxidant activity on low density lipoprotein(LDL) using substances extracted from Bacillus sp. RH-5. The antioxidative substances produced extracellular in the culture broth by Bacillius sp. RH-S was obtained by elution of chloroform : methanol from silicagel column (80cm x100cm) chromatography. Band 4 eluted from fraction 3 by TLC was appeared at highest level of antioxidative activity using thiocyanate methed. Band 4 at a concentration of 100 or 200$\mu$g/$m\ell$ inhibited oxidation of LDL induced by the mouse transformed macrophage. According to IR. NMR or GC/MASS, the antioxidant substance was identified as 5-hydroxyindole.

• 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.

• 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 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.

• 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.

• Applied Biological Chemistry
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• v.16 no.3
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• pp.112-117
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• 1973

The very low density apolipoproteins were separated by a newly developed method of isoelectric focusing in a narrow pH gradient. Four polypeptides were isolated that differed from the major proteins of the high density or low density lipoproteins. Three of these proteins had indistinguishable amino acid compositions, but different isoelectric points, COOH-terminal alanine, no isoleucine, cysteine or cystine. Two of these polypeptides had $NH_2-terminal$ serine. The polymorphism of apolipoprotein-Ala, so designated from the COOH-terminal residue, was related to sialic acid content; one form contained 2 moles of sialic acid per mole of protein, the second, 1 mole of protein, and the third, no sialic acid. The fourth polypeptide had an amino acid composition different from the first three polypeptides and from other polypetides obtained from very low density lipoprotein. This polypeptide had $NH_2-terminal$ threonine, COOH-terminal resistant to carboxypeptidase A, no histidine, cysteine, cystine or sialic acid. These four polypeptides constituted approx. 40% of the total protein in very low density lipoprotein.

• 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.