Min-Ja Lee

Dongguk University, Sŏul, Seoul, South Korea

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Publications (12)15.13 Total impact

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    ABSTRACT: The antioxidant activity of extracts from Caesalpinia sappan L. (CSL) was studied in vitro by evaluating the total phenolics, measuring the antioxidant activity by TEAC, measuring the scavenging effects on reactive oxygen species (ROS) and on reactive nitrogen species (RNS), and measuring the inhibitory effect on Cu(2+)-induced human low-density lipoprotein (LDL) oxidation. The CSL extracts were found to have a potent scavenging activity against all of the reactive species tested, as well as an inhibitory effect on LDL oxidation, especially in the ethyl acetate (EA) fraction. Therefore, we isolated and identified benzylchroman derivatives sappanchalcone (1) and 3'-deoxy-4-O-methylepisappanol (2) from the EA fraction of CSL and their antioxidant activities were evaluated. The studied CSL extracts and the compounds 1 and 2 were revealed to be very effective against the evaluated pro-oxidant species, including ROS and RNS.
    Journal of Enzyme Inhibition and Medicinal Chemistry 10/2010; 25(5):608-14. · 1.50 Impact Factor
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    ABSTRACT: In this study the potent scavenging activity of "Lycopi Herba" (LH) extract was studied using the following: evaluation of the total phenolics, measuring the antioxidant activity by Trolox equivalent antioxidant concentration, measuring the scavenging effects on reactive oxygen species, on reactive nitrogen species, and measuring the inhibitory effect on Cu(2+) induced human low-density lipoprotein oxidation in vitro. The ethyl acetate fraction from the LH extracts were found to have a potent scavenging activity against all of the reactive species tested, as well as an inhibitory effect on LDL oxidation. Therefore, we isolated and identified luteolin-7-O-beta-D-glucuronide methyl ester as the major compound from the ethyl acetate fraction of LH and their antioxidant activities were evaluated.
    Journal of Enzyme Inhibition and Medicinal Chemistry 10/2010; 25(5):702-7. · 1.50 Impact Factor
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    ABSTRACT: Oxidative stress and inflammatory mediators were measured in the plasma and livers of C57BL/6 mice fed a high-cholesterol diet for 14 weeks and in cultured human umbilical vein endothelial cells (HUVECs). Some of the mice fed with the atherogenic diet received drinking water supplemented with 0.01 g of a 70% ethanol extract of Caesalpinia sappan L. (CSLE) per 20 g of body weight. Numerous parameters were determined: concentrations of total, high-, and low-density cholesterol; atherogenic index; plasma trolox equivalent antioxidant capacity (TEAC); levels of hepatic thiobarbituric acid reactive substances (TBARS) and protein carbonyls; and the activities of hepatic antioxidant enzymes, including Cu·Zn-SOD, Mn-SOD, glutathione peroxidase, glutathione reductase, and catalase. HUVECs were stimulated with tumor necrosis factor α (TNFα) and the expression of intracellular reactive oxygen species (ROS), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), adhesion molecules, inhibitory κBα (IκBα), and nuclear factor κB (NFκB) were measured. Compared to mice fed a hypercholesterolemic diet alone, mice fed a hypercholesterolemic diet supplemented with CSLE exhibited decreased total plasma cholesterol and increased high-density lipoprotein cholesterol, and thus a lower atherogenic index. Furthermore, plasma TEAC and levels of hepatic TBARS and protein carbonyls were significantly decreased in CSLE-supplemented mice (P < 0.05), whereas all hepatic antioxidative indicators were significantly elevated (P < 0.05). In HUVECs stimulated with TNFα, CSLE significantly decreased the expression of intracellular ROS, LOX-1, and adhesion molecules; the degradation of IκBα; and the nuclear translocation of NFκB; in contrast, CSLE induced the expression of Nrf2 and HO-1 (P < 0.05 for all results).
    Immunopharmacology and Immunotoxicology 03/2010; 32(4):671-9. · 1.36 Impact Factor
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    ABSTRACT: The proliferation of vascular smooth muscle cells (VSMCs) plays a key role in the development of atherosclerosis. Abnormal VSMC proliferation induces vascular dysfunction and several other pathological processes. The present study investigated the apoptotic effects of genistein on tumor necrosis factor-alpha (TNF-alpha)-induced proliferation in human aortic smooth muscle cells (HASMCs). The apoptotic effects of genistein were assessed to determine the mechanism(s) of its antiproliferative activity, including MTT, LDH assay, morphological change of cell, DNA fragmentation, and expression levels of pro- or anti-apoptotic molecules by RT-PCR and Western blots. The results show that genistein significantly reduced cell proliferation in TNF-alpha-induced HASMCs. Genistein also reduced intracellular nuclei staining with DAPI in a dose-dependent manner. In addition, genistein increased nucleosomal DNA fragmentation, increased the expression levels of Bax and c-Myc, and decreased the expression levels of Bcl-2 and Bcl-xL in TNF-alpha-induced HASMCs. Taken together, these findings indicate that genistein regulates the activation of apoptosis-related molecules in TNF-alpha-induced HASMCs, leading to the suppression of proliferation and induction of apoptosis.
    Journal of Agricultural and Food Chemistry 02/2010; 58(3):2015-9. · 3.11 Impact Factor
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    ABSTRACT: In Leonurus sibiricus herb extract (LHE)-supplemented animals, plasma cholesterol decreased and high-density lipoprotein-cholesterol increased, resulting in a lowered atherogenic index. The plasma trolox equivalent antioxidant capacity, levels of hepatic thiobarbituric acid-reactive substances, and protein carbonyl values decreased significantly in LHE-supplemented mice (p<0.05), whereas the hepatic antioxidant indicators were all significantly elevated (p<0.05). In human umbilical vein endothelial cells stimulated with tumor necrosis factor alpha, LHE significantly suppressed intracellular reactive oxygen species, LOX-1, and adhesion molecules. LHE supplementation may modulate the lipoprotein composition and attenuate oxidative stress by elevated antioxidant processes, thus suppressing the activation of inflammatory mediators. This is a possible mechanism of the anti-atherogenic effect.
    Bioscience Biotechnology and Biochemistry 02/2010; 74(2):279-84. · 1.27 Impact Factor
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    ABSTRACT: In this study, the anti-oxidative activities of 70% ethanol extract from Curcuma aromatica Salisb. (CAS) and curcumin (CUR) were studied. The CAS extracts and CUR were both found to have a potent scavenging activity against the reactive species tested, as well as an inhibitory effect on LDL oxidation. Cultured human umbilical vein endothelial cells (HUVECs) were stimulated with tumour necrosis factor alpha (TNFalpha), expression of intracellular reactive oxygen species (ROS), nitric oxide (NO), endothelial nitric oxide synthase (eNOS), lectin-like oxidised LDL receptor-1 (LOX-1), adhesion molecules, inhibitory kappa Balpha (IkappaBalpha) and nuclear factor kappa B (NFkappaB) were measured. In HUVECs stimulated with TNFalpha, CUR significantly suppressed expression of the intracellular ROS, LOX-1 and adhesion molecules, degradation of IkappaBalpha and translocation of NFkappaB, while inducing production of NO by phosphorylation of eNOS (p <0.05). In conclusion, CAS and CUR may modulate lipoprotein composition and attenuate oxidative stress by elevated antioxidant processes.
    Journal of Enzyme Inhibition and Medicinal Chemistry 02/2010; 25(5):720-9. · 1.50 Impact Factor
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    ABSTRACT: This study was designed to investigate whether bamboo culm extract (BCE) supplementation may ameliorate risk factors of cardiovascular diseases, such as hypercholesterolemia. Oxidative stress and inflammatory mediators in plasma, livers of C57BL/6 mice fed high-cholesterol diet and calf pulmonary artery endothelial (CPAE) cells. Briefly, C57BL/6 mice were fed the high-cholesterol diet which was supplemented with 1% (w/w), or 3% (w/w) of BCE for 16 weeks. The concentration of total cholesterol, LDL-cholesterol, HDL-cholesterol level and atherogenic index were measured. Plasma TEAC value, hepatic thiobarbituric acid reactive substances (TBARS), protein carbonyl values and hepatic antioxidant enzyme activities, such as Cu,Zn-superoxide dismutase (SOD), Mn-SOD, glutathione peroxidase (GSH-Px), GSH reductase and catalase were determined. In addition, hepatic nuclear factor kappa B activities were detected. In the calf pulmonary artery endothelial (CPAE) cells stimulated with lipopolysaccharide, the expression of vascular cell adhesion molecule-1 (VCAM-1) and intracellular cell adhesion molecule-1 (ICAM-1) were measured. Plasma cholesterol level was decreased, while HDL-cholesterol was increased, thus atherogenic index was lowered in BCE-supplemented animals. Plasma trolox equivalent and hepatic thiobarbituric acid reactive substances and protein carbonyl values were lowered significantly in BCE groups (p<0.05) in a dose-dependent manner. Hepatic antioxidative enzyme activities, such as Cu,Zn-superoxide dismutase (SOD), Mn-SOD, glutathione peroxidase (GSH-P), GSH reductase, and catalase were elevated in mice fed BCE-supplemented diets (p<0.05). Nuclear factor kappa B activities of livers and vascular cell adhesion molecule-1 and intracellular cell adhesion molecule-1 expressions in CPAE cells stimulated with lipopolysaccharide were significantly lowered in BCE groups (p<0.05). These results suggest that BCE supplementation may modulate lipoprotein composition and attenuate oxidative stress by elevated antioxidative processes, thus suppressing inflammatory mediator activation as possible mechanism of its anti-atherogenic effect.
    Clinical nutrition (Edinburgh, Scotland) 10/2008; 27(5):755-63. · 3.27 Impact Factor
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    ABSTRACT: Previously, we reported that bamboo culms possess a stronger antioxidative capacity than bamboo leaves in vitro. In this study, we investigated whether bamboo culm extract (BCE) supplementation ameliorates oxidative stress and hepatic nuclear factor kappaB (NF kappa B) activation in C57BL/6 mice fed an atherogenic diet. In addition, the effect of BCE supplementation on plasma lipid levels of the animals was tested. The mice were randomly assigned to a normal diet, an atherogenic diet (control), or an atherogenic diet supplemented with 1% (wt/wt) BCE or 3% (wt/wt) BCE for 16 weeks. Atherogenic diet-induced oxidative stress, measured by hepatic thiobarbituric acid-reactive substances and protein carbonyls, was significantly lower in the BCE-supplemented groups than in the control (P < .05). Total antioxidative capacity was elevated in the BCE groups, along with greater activities of antioxidative enzymes such as superoxide dismutase and catalase, compared to the control or normal groups (P < .05). The hepatic NF kappa B binding activities were significantly lower in the BCE groups as well (P < .05). The high-density lipoprotein-cholesterol level was significantly elevated by BCE supplementation (P < .05), whereas the effects of BCE on triglyceride and total cholesterol were inconsistent. Results from this study suggest that BCE supplementation may lessen oxidative stress via a series of changes, including a reinforced antioxidant system, and also suggest that the lowered oxidative stress status may down-regulate the activation of inflammatory mediators.
    Journal of Medicinal Food 03/2008; 11(1):69-77. · 1.64 Impact Factor
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    ABSTRACT: To evaluate the antimutagenic effect and hepato protective of bamboo trees and bamboo byproduct, hot-water extracts from four kinds of bamboo [wang-dae (Phyllostachys bambusoides S. et Z.), som-dae (Phyllostachys nigra var. henonis), maengjong-juk (Phyllostachys pubescens) and o-juk (Phyllostachys nigra Munro)] and maengjong-juk extract coated rice were evaluated for antimutagenicity by Ames test using Salmonella typhimurium TA100. Bamboo extracts showed strong antimutagenic activity in the Ames test which MNNG was used as mutagen in the absence and presence of S9 mix. Maengjong-juk extract coated rice diet suppressed the loss of body weight significantly. Food intake was increased in maengjong-juk extract coated rice supplemented group but showed no significant differences between control and maengjong-juk extract coated rice diet groups. Food efficiency of maengjong-juk extract coated rice supplemented group was significantly higher than that of the control group. Liver weight was significantly increased by maengjong-juk extract coated rice diet administration. Plasma GOT & GPT activities of rabbit were significantly suppressed in maengjong-juk extract coated rice supplemented group. These results suggest that bamboo trees extracts and maengjong-juk extract coated rice are bioavailable resource on treatment of cardiovascular disease, such as atherosclerosis and hypercholesterolemia.
    Journal of the Korean Society of Food Science and Nutrition 01/2004; 33(8).
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    Gap-Soon Moon, Bog-Mi Ryu, Min-Ja Lee
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    ABSTRACT: Changes in amino acids content and antioxidative activity in the leaves of buchu (Allium tuberosum R.) at different harvesting times were investigated. Contents of protein, lipids and ash were the highest at the first harvest time, but decreased thereafter, whereas water content showed the reverse pattern. Amino acid contents were the highest at 2nd harvest time, major compositions being aspartic acid, alanine, and glutamic acid, which decreased thereafter. Antioxidative activities according to harvesting times also revealed the same pattern showing by the major nutrients. Correlation coefficients between antioxidative detecting methods in TEAC vs FRAP assay, FRAP vs DPPH assay, and TEAC vs DPPH showed 0.996, 0.992, and 0.987, respectively (p
    Korean Journal of Food Science and Technology. 01/2003; 35(3).
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    Min-Ja Lee, Gap-Soon Moon
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    ABSTRACT: Bamboo trees have been used for a long time as folk remedies for treatment of hypertension and stroke symptoms in Oriental regions. These pharmaceutical effects of bamboos look like to be related to its antioxidant capacity and phytochemicals in bamboos. To evaluate the antioxidative effects of bamboo trees, five kinds of bamboo varieties dominant in Korean peninsular were chosen and determined its total antioxidaive activities, free radical scavenging activities and nitrite scavenging activities by TEAC (Trolox Equivalent Antioxidant Capacity) assay, DPPH and Griess reagent assay using in vitro system, respectively. To evaluate the correlation between antioxidative activities and Maillard reaction during hot water extraction, contents of reducing sugar and total nitrogen and brown color intensity at 420 nm were determined. When total antioxidative activities, free radical scavenging activities and nitrite scavenging activities of five kinds of bamboo trees were compared, wang-dae (Phyllostachys bambusoides S. et Z.) showed the strongest effect among samples, although all kinds of extracts showed relatively strong effects against oxidation. The bamboo culms extract showed stronger antioxidative effects than that of bamboo leaves. In each fraction obtained from 70% ethanol extract, antioxidative effect were increased in order of dichloromethane>ethyl acetate>butanol>water>hexane fraction. In reducing sugar analysis of extracts, reducing sugar contents of water extracts were higher than that of 70% ethanol extracts and wang-dae water extract showed the highest level which was 708.92 mg/g. Total nitrogen contents of the extracts were and contents in water extracts were lower than that in 70% ethanol extracts. Brown color intensity at 420 nm showed similar tendency with results in reducing sugar contents.
    Korean Journal of Food Science and Technology. 01/2003; 35(6).
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    ABSTRACT: Protective effect of skin by antioxidative dietary buchu (Chinese chives, Allium tuberosum Router), was evaluated in ICR mice fed diets containing 2% or 5% buchu for 12 months. Lipid peroxidation and protein oxidation in skin, with or without ultraviolet B (UVB) irradiation, activities of antioxidative enzymes, total glutathione concentrations, and non-soluble collagen contents were measured. Dietary buchu decreased significantly in TBARS and protein carbonyl levels in skin compared to the control group, and were lower in those fed 5% than 2% buchu diet group. ICR mice exhibited an age-dependent decrease in antioxidative enzyme activities and total glutathione concentrations on the control diet, but in the groups fed buchu diet the enzyme activities and glu-tathione concentrations remained at youthful levels for most of the study. SOD, glutathione peroxidase, and catalase activities as well as total glutathione concentrations increased with time in the skins of the mice fed buchu diets. Lipid peroxidation and protein oxidation provoked by UVB irradiation on ICR mice skin homogenates were also significantly inhibited by dietary buchu. The buchu diets also decreased the formation of non-soluble collagen in mice skin, compared to the control group. These results suggest that antioxidative components and sulfur-compounds in buchu may confer protective effect against oxidative stress resulting from aging and exposure to ultraviolet irradiation.
    Preventive Nutrition and Food Science. 01/2002; 7(3).