• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.25-31
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• 1997

Antioxidative activity of daidzin and puerarin isolated from Puerariae radix against oxidation of low density lipoprotein(LDL) was investigated. The concentration of daidzin at 100$\mu\textrm{g}$/$m\ell$ and puerarin at 60$\mu\textrm{g}$/$m\ell$ inhibited Cu$^{2+}$-mediated oxidation of LDL almost completely. The electrophoretic mobility of oxidized LDL by addition of daidzin(100$\mu\textrm{g}$/$m\ell$) and puerarin(60$\mu\textrm{g}$/$m\ell$) was faster than that of native LDL, but slower than that of oxidized LDL. The oxidized LDL induced by J774 or macrophage was inhibited strongly in the presence of 100$\mu\textrm{g}$/$m\ell$ daidzin and 60$\mu\textrm{g}$/$m\ell$ Puerarin. The formation of conjugated dienes in the oxidized LDL was strongly inhibited by 100$\mu\textrm{g}$/$m\ell$ daidzin and 60$\mu\textrm{g}$/$m\ell$ puerarin.n.

• 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.12 no.2
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• pp.144-150
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• 2002

This experiment was designed to investigate the antioxidant effects of Chrysanthemum coronarium L. (CC) fractions on the liposomal phospholipid membranes. The sample CC was extracted and fractionated into five different types, methanol (CCMM), hexane (CCMH), ethylacetate (CCMEA), butanol (CCMB), and aqueous (CCMA) fractions. The antioxidant activities of CC fractions in oxidized dilinoleoylphosphatidylcholine (DLPC) liposomes were examined by spectrophotometry measuring conjugated dienes. The oxidation indices of five CC fractions exhibited weaker antioxidant activities than that of BHT in oxidized DLPC liposomes, however, showing much similar antioxidant activities of $\alpha$-tocopherol in the oxidized DLPC liposomes, which is known as a potent antioxidant. Among CC fractions, CCMM and CCMA in oxidized DLPC liposomes showed rather effective than $\alpha$-tocopherol after 2 h. These results strongly indicate that bioactive substances in CC fractions have a kind of function as potent antioxidants against biomembrane oxidation.

• Applied Biological Chemistry
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• v.37 no.3
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• pp.168-174
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• 1994

Effects of filtration and centrifugation on the oxidative stabilities of sesame oils during storage at $70^{\circ}C$ were studied by combination of determining peroxide values and conjugated dienoic acid values of oils and measuring the hexanal formation using headspace gas chromatography. Crude sesame oil from roasted seeds contained more free fatty acids, conjugated dienes, and metals (Fe, Cu, Mg and Zn); on the other hand, higher contents of moisture and ${\gamma}-tocopherol$ were found in the filtered or centrifuged oil. Only filtered oil contained more peroxides than the crude oil in spite of the color advantage of the highest L and b values among three oils. All the oils showed the tendency of increasing in total color difference during storage at $70^{\circ}C$, fatty acid compositions were relatively constant except for decreasing tendency of linoleic acid in filtered oil. No significant difference at 1% in the oxidative stabilities was observed between centrifuged oil and crude oil with higher susceptibility to the oxidation in the filtered oil. Centrifuged sesame oil was the best in the aspect of both oxidative stability and the oil color.

• School Mathematics
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• v.8 no.4
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• pp.417-439
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• 2006

Many studies indicate the emerging crisis of education of calculus even though the emphasis of calculus have been widely recognized. In our classrooms, the education of calculus also has been faced with its bounds. Most instructions of calculus is too much emphasis on the algebraic approach, thus students solve mathematical problems without truly understanding the underlying concept. The purpose of this study is to develop mathematization teaching and learning materials and methods in caculus based on the mathematization teaching and learning theories by Freudenthal and the variability principles of conceptual learning by Dienes, In order to this purpose, first, we analyzed the high school mathematics II textbook of 7th curriculum in Korea. Second, we developed mathematization teaching and learning materials and methods in highschool calculus. Consequently, the following conclusions have been drawn: we have reorganized and reconstructed the context problem in calculus based on concepts of tangent line and instantaneous rate of change.

• Archives of Pharmacal Research
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• v.25 no.2
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• pp.184-191
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• 2002

We investigated the role of vitamin C or rutin on neuropathy and lung damage of diabetic mellitus(DM) rats. Norepinephrine content was significantly decreased in sciatic nerves of DM rats compared with non-DM controls but vitamin C had no effect on decreases of norepinephrine. 2,4-dinitrophenylhydrazine (DNPH) incorporation, which is biomarker of protein oxidation, was increased in sciatic nerve of DM rats as compared with normal control. However, vitamin C had no effects on increases of DNPH incorporation . We measured the content of conjugated dienes (CD) as a biomarker of lipid oxidation in sciatic nerve. CD was increased in DM as compared with normal control, Vitamin C or rutin had no effects on increases of CD. However, Rutin plus vitamin C significantly decreased the content of CD as compared with CIM rats. In lung of DM rats, DNPH incorporation or CD was increased as compared with normal control. Vitamin C or Rutin had no effects on increases of CD However, Rutin plus vitamin C significantly decreased the content of DNPH incorporation or CD in lung tissue. Vitamin C caused marked pathological changes such as the increases of parenchyma and the thickening of alveolar septa in the lung of DM. Rutin had protective effects on the pathological changes in the lung of DM rats. In conclusion, Vitamin C had no effects on oxidative parameter, such as DNPH incorporation or CD, and on the decreases of norepinephrine content in DM rats. Vitamin C caused the marked pathological changes in the lung of DM rats but rutin had protective efforts against the pathological changes.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.420-425
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• 1987

For use of sardine oil as an ingredient of food and feed, crude sardine oil obtained by rendering was processed to RBD sardine oil. Alkali deacidification was found to be most efficient with a concentration of 2.5N NaOH and 0.5% excess level at $75^{\circ}C$. Treatment with activated clay alone at $105^{\circ}C$ for 20 min without air admission was effective in reduction of the color intensity of the oil without any formation of the conjugated dienes and trienes of polyunsaturated fatty acids. In deodorization process, as the temperature was increased, color of the oil was to become lighter. The amount of conjugated compounds was, however, increased drastically at higher temperatures above $180^{\circ}C$ for 1hr. and content of polyunsaturated fatty acids was significantly decreased.

• Preventive Nutrition and Food Science
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• v.19 no.1
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• pp.19-26
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• 2014

Increased consumption of fresh vegetables that are high in polyphenols has been associated with a reduced risk of oxidative stress-induced disease. The present study aimed to evaluate the antioxidant effects of spinach in vitro and in vivo in hyperlipidemic rats. For measurement of in vitro antioxidant activity, spinach was subjected to hot water extraction (WE) or ethanol extraction (EE) and examined for total polyphenol content (TPC), oxygen radical absorbance capacity (ORAC), cellular antioxidant activity (CAA), and antigenotoxic activity. The in vivo antioxidant activity of spinach was assessed using blood and liver lipid profiles and antioxidant status in rats fed a high fat-cholesterol diet (HFCD) for 6 weeks. The TPC of WE and EE were shown as $1.5{\pm}0.0$ and $0.5{\pm}0.0mg$ GAE/g, respectively. Increasing the concentration of the extracts resulted in increased ORAC value, CAA, and antigenotoxic activity for all extracts tested. HFCD-fed rats displayed hyperlipidemia and increased oxidative stress, as indicated by a significant rise in blood and liver lipid profiles, an increase in plasma conjugated diene concentration, an increase in liver thiobarbituric acid reactive substances (TBARS) level, and a significant decrease in manganese superoxide dismutase (Mn-SOD) activity compared with rats fed normal diet. However, administration of 5% spinach showed a beneficial effect in HFCD rats, as indicated by decreased liver TBARS level and DNA damage in leukocyte and increased plasma conjugated dienes and Mn-SOD activity. Thus, the antioxidant activity of spinach may be an effective way to ameliorate high fat and cholesterol diet-induced oxidative stress.

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.123-129
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• 2014

The antioxidant and antimicrobial activities of Camellia oleifera seed oil were studied. Four kinds of seed oil samples were prepared, crude oil and refined oil, extracted by cold pressing method (CPC, CPR), and organic solvent extraction (OSC, OSR). Antioxidant activity analysis was measured in 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)-diammonium salt, ferric reducing Ability of Plasma, and 2,2-diphenyl-1-picrylhydrazyl assays. Besides, the percentage of inhibition of red blood cells hemolysis induced by 2,2'-azobis(2-amidnopropane) dihydrochlorid, the lag time of LDL conjugated dienes formation in vitro, and the inhibitors of loss in tryptophan fluorescence were all used to estimate the antioxidant activity of the samples. The total phenolic contents (TPC) were detemined by Folin-Ciocalteu method. The TPC of the C. oleifera seed oils can be arranged in descending order: CPC ($1.9172{\mu}g/mL$) > OSC ($1.5218{\mu}g/mL$) > CPR ($1.0611{\mu}g/mL$) > OSR ($0.6782{\mu}g/mL$). And the oils were investigated for activity against Escherichia coli, Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus niger. The results showed the antioxidant activity of crude oil by cold pressing method was stronger than others, and all oils did inhibit activity of the top three bacteria expert A. niger. The further significance of the study contributes to measure the antioxidant and antimicrobial activity of the potential health benefits by the different methods of preparation and the oil of C. oleifera seeds acting as free radical scavenger, pharmaceuticals and preservatives may offer some information in medicine and cosmetic not just in food field.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.446-458
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• 2019

The aim of this study was to investigate the oxidative status and quality characteristics of four animal skin-derived fats extracted using an identical extraction method. Pressurized hot water extraction, a green extraction method, was used to extract animal skin fats (duck, chicken, swine, and bovine skin). Multiple experiments were performed during accelerated storage at $60^{\circ}C$ for 90 days. Quality characteristics, such as extraction yield, iodine value (IV), fatty acid composition, and fat viscosity were determined. In addition, indicators for oxidative status, including acid value (AV), peroxide value (PV), p-anisidine value (p-AV), thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD), and total oxidation (totox) values were evaluated. The fat extraction yield was highest in bovine fat, followed by duck, swine, and chicken fats. The IV was higher in duck and chicken fats. Duck fats contained the most unsaturated fats and the least saturated fats. Fat oxidation indicators, such as PV, TBARS, and totox values, were relatively higher in duck fats during storage compared to the other fats. Other indicators, including AV, p-AV, and CD, were similar in duck, chicken, and swine fats. Viscosity was similar in all the tested fats but markedly increased after 70 days of storage in duck fats. Our data indicate that duck skin fat was more vulnerable to oxidative changes in accelerated storage conditions and this may be due to its higher unsaturated fatty acid content. Supplementation with antioxidants might be a reasonable way to solve the oxidation issue in duck skin fats.