• Title/Summary/Keyword: LDL Oxidation

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Enhanced Uptake of Modified Low-Density Lipoprotein by Eicosapentaenoic Acid-Treated THP-1 Macrophages

  • Kang, Young-Hee;Park, Sung-Hee;Kang, Jung-Sook;Park, Jung-Han-Yoon
    • Nutritional Sciences
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    • v.4 no.1
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    • pp.26-33
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    • 2001
  • Animal and clinical studies as well as epidemiological data have provided convincing evidence that n-3 polyunsaturated fatty acids can protect against atherosclerosis. However, the effects of the fatty acids on atherogenesis are contradictory. This discrepancy could derive from great susceptibility of the fatty acids to oxidation. We investigated the effect of eicosapentaenoic aced(EPA) on cellular atherogenesis via the scavenger receptor of THP-1 derived macrophages. THP-1 cells were fully differentiated into macrophages by incubating with phorbol 12-myristate 13-acetate for seven days. Atherogenic features of EPA were compared by subsitituting for linoleic acid (LA). Macrophages were also incubated without treatment of the fatty acids as controls. EPA (5-50 nmol/mL) was not cytotoxic and did not measurably induce cellular oxidation compared to bovine serum albumin (BSA) vehicle or identical doses of LA. EPA increased macrophage uptake and degradation of acetylated LDL(AcLDL) up to 14% and 88%, respectively. EPA increased markedly total cellular sterol synthesis and heparin-releasable lipoprotein lipase activity of macrophages, indicating that EPA may enhance accumulation of cellular cholesteryl ester and possibly facilitate formation of foam cells. These results demonstrate that EPA promotes the modified LDL-triggered atherosclerotic process by the modulation of the scavenger receptor and the activation of LPL in macrophages.

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Screening of Anti-atherogenic Substances from Insect Resources (곤충자원으로부터 항동맥경화 활성물질 탐색)

  • Park, Doo-Sang;Yoon, Mi-Ae;Xu, Ming-Zhe;Yu, Ha-Na;Kim, Ju-Ryoung;Jeong, Tae-Sook;Park, Ho-Yong
    • Korean Journal of Pharmacognosy
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    • v.35 no.3 s.138
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    • pp.233-238
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    • 2004
  • Lipoprotein-associated phospholipase $A_2\;(Lp-PLA_2)$ is a potential biomarker of coronary heart disease and plays an important proinflammatory role in the progression of atherosclerosis. Also acyl-CoA: cholesterol acyltransferase (ACAT) and oxidized low-density lipoprotein (LDL) playa key role in atherosclerosis, respectively. And so, the inhibitory activities of the methanol extracts of 42 insect resources were examined on $Lp-PLA_2$, ACAT, and LDL oxidation for screening of anti-atherogenic substances. Among them, the methanol extracts of Eurydema rugosa significantly inhibited all of upper three activities. Several kinds of tested insects having high inhibitory effect with the methanol extracts were extracted with n-hexane, ethyl acetate, and acetone, and their inhibitory activities were tested.

Inhibitory Effect against Angiotensin Converting Enzyme and Antioxidant Activity of Panax ginseng C. A. Meyer Extracts (인삼 추출물의 Angiotensin Converting Enzyme 저해 효과와 항산화 활성)

  • Lee, Seung-Eun;Seong, Nak-Sul;Bang, Jin-Ki;Kang, Seung-Won;Lee, Sung-Woo;Chung, Tae-Yung
    • Korean Journal of Medicinal Crop Science
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    • v.11 no.3
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    • pp.236-245
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    • 2003
  • The study was performed for elucidating angiotensin converting enzyme (ACE) inhibitory activity and comparing antioxidative activity of Panax ginseng extracts prepared at different conditions. Total phenolic content, inhibitory activity on ACE and antioxidative effects were tested on 10 ethanolic extracts and correlation coefficient between total phenolic content and physiological activity was calculated. Yield and total phenolic content of 50% ethanolic extract prepared at $85^{\circ}C$ exhibited the highest value as 42.52% and 0.82%, respectively. Among the fractions obtained from 50% ethanolic extract prepared at room temperature, water fraction showed the highest value in yield as 72.08% and ethyl acetate fraction did in total phenolic content as 6.59%. In the test on ACE inhibitory activity, 50% ethanolic extract obtained at room temperature indicated the strongest effect of 93.8% which was higher than 85.2% of commercialized ACE inhibitor and solvent fractions showed potent inhibitory activity in order of hexane fraction, diethyl ether fraction, ethyl acetate fraction, butanol fraction and water fraction at concentration of $4000{\mu}g/ml$. 50% Ethanolic extract prepared at $85^{\circ}C$ had the most potent inhibition effect on human LDL oxidation as 78.2% at $200{\mu}g/ml$ and the other extracts also did above 60%. Diethyl ether fraction and ethyl acetate fraction showed strong inhibition activity $(34.38%{\sim}78.13%)$ on LDL oxidation at concentration of $10{\sim}200\;{\mu}g/ml$. From the statistical analysis via SAS program, correlation coefficient between total phenolic content and ACE inhibitory effect was 0.6353 at P<0.05. Conclusively, this report showed that the most efficient extraction condition for elevating inhibitory activity on ACE and LDL oxidation, phenolic content and yield from Panax ginseng was 50% ethanol extraction at room temperature or high temperature condition. And Panax ginseng would be used for preventing hypertension or atheroscrelosis for man via inhibitory action on ACE and LDL oxidation.

Effects of Ligularia fischeri Extracts on Oxidation of Low Density Lipoprotein (저밀도 지방단백질의 산화에 대한 곰취 추출물의 항산화 효과)

  • Jeong, Seong-Won;Kim, Eun-Jeong;Hwangbo, Hyun-Ju;Ham, Seung-Shi
    • Korean Journal of Food Science and Technology
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    • v.30 no.5
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    • pp.1214-1221
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    • 1998
  • The study was carried out to investigate the antioxidant effects of ethanol, methanol, and water extracts or fractions of ethanol extract of Ligularia fischeri on low density lipoprotein(LDL) and ethanol extract was further fractionated. The methanol extract and ethyl acetate fraction showed strong antioxidant effect with 71.7% (13.36 nmol/mg) and 95% (1.35 nmol/mg) inhibition in the presence of $15\;{\mu}g/mL$, respectively. In the value of malondialdehyde(MDA) with oxidation time, ethanol, methanol and water extract in the presence of $25\;{\mu}g/mL$ inhibited the oxidation up to 4h incubation and ethyl acetate fraction showed strong antioxidant effect up to 8h incubation. Also, the ethanol, methanol and water extract showed antioxidant effects in the agarose gel electrophoresis test. The conjugated diene formation by lipid oxidation with addition of $Cu^{2+}$ in the Ligularia fischeri extracts and their fractions was decreased approximately 1.1 to 2.8 times and 2.2 to 3.2 times, respectively compared to control. In the degradation of apo B-100 by oxidation using SDS-PAGE, ethanol, methanol and water extract showed similar degradation band pattern compared to that of native LDL band. Apo B-100 contents using densitometer were 77.8, 92.5% and 82.3% in the ethanol, methanol and water extract, respectively, compared to 100% of native LDL. In the meanwhile, apo B-100 contents in hexane, ethyl acetate and water fraction were 38.8, 94.5 and 65.5% respectively. This results indicated that ethyl acetate fraction showed the strongest antioxidant effect on MDA value or apo B-100 contents of LDL.

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Discovery of Antioxidant on Human Low Density Lipoprotein (LDL) by Bacillus sp. RH-5 Isolated from Marine Origin (해양에서 분리한 Bacillus sp. RH-5에 의한 사람 Low Density Lipoprotein(LDL) 산화에 대한 항산화제의 개발)

  • 류병호;박종옥;김동석
    • 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.

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Antioxidant Activity of major protein from Panax Ginseng C.A. Meyer.

  • Kim, Min-Jung;Sok, Dai-Eun
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.146.1-146.1
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    • 2003
  • A major protein was isolated from ginseng root (Panax ginseng C.A. Meyer) using a combination of ammonium sulfate fractionation, gel filtration chromatography, ion-exchange FPLC. Electrophoretic and gel permeation chromatographic studies revealed that the major protein, GMP, is composed of two subunits of approximately 28 kDa. In this, investigated the ability of GMP to inhibit the oxidation of low-density lipoprotein (LDL). GMP inhibited $Cu^{2+}$ (5$\mu$M)-promoted oxidation of LDL (125$\mu$g protein/mL) in a dose-dependent mamer (0~5 $\mu$M), with a maximal inhibitor at GMP/copper ratio of 1:10 and an $IC_{50}$ value of 0.2 $\mu$M, as determined by measurement TBARS. (omitted)

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Antioxidative Activities of Triterpenoids and Lignans from Acanthopanax divaricatus var. albeofructus (백모오가피로부터 분리된 트리터페노이드 및 리그난의 항산화작용)

  • 김지연;양기숙
    • YAKHAK HOEJI
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    • v.48 no.4
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    • pp.236-240
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    • 2004
  • Acanthopanax species (Araliaceae) traditionally has been used as analgesics, stimulant of immune system, and replenishment of body functions. Acanthopanax divaricatus var. albeofructus is indigenous plant to Korea. The antioxidant activities of compounds from A divaricatus var. albeofructus were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and thiobarbituric acid reactive substance (TBARS) assay on human plasma low-density lipoprotein (LDL). The triterpenoid and lignan constituents from this plant showed antioxidant activities and the lignan, l-sesamin exhibited the most potent antioxidant activity in Cu$^{2+}$ -induced LDL oxidation.n.