Soung-Jin Houng

Korea University, Seoul, Seoul, South Korea

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Publications (7)12.94 Total impact

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    ABSTRACT: To investigate the hypocholesterolemic mechanism of barley in vivo, six-week-old C57BL/6J mice were fed a high-fat diet (HFD) or high-fat diet containing barley (HFD-B) for seven weeks. Total and LDL cholesterol concentrations were significantly reduced in the HFD-B group while fecal cholesterol and bile acid was increased. Real-time PCR and immunoblot analysis revealed the induction of FXR expression, which in turn suppressed the expression of ASBT and NPC1L1 in the HFD-B group compared with the controls. In the liver, the expression of HMG-CoA reductase was significantly reduced while LDL receptor expression was unaltered in the HFD-B group compared with the controls. Our data suggest that the hypocholesterolemic effects of barley are primarily the result of reduced dietary cholesterol uptake and bile acid resorption. Reduced expression of intestinal ASBT and NPC1L1 may play a key role in the regulation of dietary cholesterol and bile acid metabolism in mice consuming a diet containing barley.
    Journal of Agricultural and Food Chemistry 06/2011; 59(12):6798-805. · 3.11 Impact Factor
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    ABSTRACT: Nanoemulsification of nutrients could improve bioavailability by enhancing intestinal uptake. We investigated the antioxidant and hypolipidemic effects of nanoemulsified green tea extract (NGTE). Antioxidant effect was measured by 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assay and dichlorofluorescein diacetate (DCFH-DA) assay. C57BL/6 mice were fed a control high-fat diet, green tea extract (GTE), or NGTE diet for 4 weeks. In composition analysis, GTE and NGTE contained similar total catechin concentrations. The antioxidative effect of GTE was comparable with that of NGTE. In the ABTS assay, GTE had a marked effect, although NGTE was more effective than GTE in the DCFH-DA assay. In the mouse feeding experiment, total and low-density lipoprotein (LDL) cholesterol concentrations were significantly reduced after NGTE treatment in comparison with GTE treatment in high-fat-fed C57BL/6J mice over the course of 4 weeks. The hypocholesterolemic effects were greater in the NGTE group compared with the GTE group (24% vs. 15.4% LDL cholesterol reduction compared with the control). Expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase was significantly down-regulated. Protein expression of LDL receptor was significantly increased in the livers of both the GTE- and NGTE-treated groups (+234.1%, P<.01 and +274.7%, P<.001), with a greater effect in the NGTE than in the GTE group. Cholesterol 7α-hydroxylase gene expression was similarly increased in both the GTE and NGTE groups. These results suggest that nanoemulsification significantly increased hypocholesterolemic effects of GTE in vivo due to increased bioavailability.
    The Journal of nutritional biochemistry 03/2011; 23(2):186-91. · 4.29 Impact Factor
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    ABSTRACT: The potential toxicity of fucoidan from Undaria pinnatifida was investigated in vitro and in vivo. By the Ames test, fucoidan showed no mutagenicity up to 500 microL/plate, and inhibited the mutagenicity induced by 4-nitro-quinoline-1-oxide, by up to 71%, compared with controls. In the bone marrow micronucleus test, fucoidan, at all levels tested, did not change the micronucleated polychromatic erythrocyte percentage ratio in mouse bone marrow cells. As an acute in vivo toxicity test, fucoidan from 0 to 2000 mg/kg body weight per day was administered orally to Sprague-Dawley rats for 28 days. No significant toxicological change was induced by fucoidan treatment up to 1000 mg/kg body weight per day in biochemical analyses, hematological analyses, necropsy and liver histopathology. The plasma ALT level was slightly, but significantly, increased in male rats at 2000 mg/kg/day. The consumption of fucoidan from Undaria pinnatifida, up to 1000 mg/kg body weight per day, may be safe in rodents, with no sign of toxicity after up to 28 days of daily administration.
    Phytotherapy Research 07/2010; 24(7):1078-83. · 2.07 Impact Factor
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    ABSTRACT: The effects of wild type and UV-irradiated lemon balm (Melissa officinalis) ethanolic extracts (MOE and UMOE) on melanogenesis in vitro were examined. UMOE showed potent antioxidant activity and significantly inhibited the mushroom and melanocyte tyrosinase activity, and lowered cellular melanin content by 49% at 200 μg/mL in B16-F1 melanocytes. The key gene and protein expression of tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 were reduced (−73% for TRP-1 protein at 200 μg/mL UMOE, p<0.05). MOE showed similar results to a slightly lesser degree. We found that myo-inositol, a major compound in lemon balm extracts, significantly reduced cellular melanin synthesis and its effect was greater than arbutin at 1 mM. These suggest that both MOE and UMOE have anti-melanogenic role by both direct inhibition of tyrosinase and down-regulation of gene expressions in melanogenesis. UV-irradiation slightly improved the anti-melanogenic activities. UMOE may be useful as natural anti-melanogenic biomaterials for functional foods and cosmetics. Keywordslemon balm (Melissa officinalis)–hypopigmentation–tyrosinase–UV-irradiation
    Food science and biotechnology 20(4):1051-1059. · 0.70 Impact Factor
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    ABSTRACT: Puerarin, an isoflavone derived from kudzu roots, has strong biological activities. However, its bioavailability in vivo is often limited by its insolubility. A novel transglycosylase increases the solubility of puerarin >100-fold, by converting it to puerarin glycosides. Since over-consumption of an isoflavone might have toxic effects, therefore, we investigated the potential antimutagenic activity, bone marrow micronucleus test, and a 28-day oral repeated administration test with puerarin and its glycosides. In Ames tests, neither puerarin nor its glycosides exhibited mutagenic effects up to 200μg/plate. Puerarin and its glycoside, glucosyl-α-(1,6)-puerarin, significantly reduced the mutagenic effect of 4-nitroquinoline-1-oxide by up to 41%. In bone marrow micronucleus tests using ICR mice, neither puerarin nor glucosyl-α-(1,6)-puerarin interfered with erythrocyte production in the bone marrow. Both compounds decreased the prevalence of polychromatic erythrocytes. Sprague–Dawley rats were orally dosed with puerarin and its glycosides daily for 28days. Neither puerarin nor its glycosides caused significant alterations in histology, and biochemical and hematologic parameters. These results suggest that puerarin and its glycosides do not have significant toxic effects, at least in rodents, either in vitro or in vivo at doses of up to 250mg/kg per day.
    European Food Research and Technology 230(1):145-153. · 1.39 Impact Factor
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    ABSTRACT: Hypolipidemic effects of Agastache rugosa essential oil (AREO) were investigated. Gas chromatographymass spectrometry (GC-MS) analysis showed that the major compound in AREO is limonene (47%, w/w). AREO (1 mg/mL) markedly reduced low density lipoprotein (LDL) oxidation (−93%). After 3-week feeding of AREO, plasma cholesterol (−28%) and triglyceride levels (−26%) were significantly decreased in C57BL/6J mice. Mouse hepatic transcriptome profiling with oligonucleotide microarray revealed that AREO altered the expression of 2,524 genes. Notably, significant reductions in sterol regulatory element binding factor (SREBF)-1 and SREBF-2 mRNA levels were detected. Protein expression of HMG-CoA reductase, a major target for SREBP-2, was reduced in HepG2 cells (−36%) and in mouse liver (−35 %). AREO also significantly increased mRNA (+40%) and protein (+83%) expression of the LDL receptor in HepG2 cells and mouse liver, respectively. Our findings suggest that AREO may prevent atherosclerosis via the inhibition of LDL oxidation, down-regulation of SREBF-2 and HMG-CoA reductase expression, and up-regulation of LDL receptor expression. Keywords Agastache rugosa (Korean mint)-cholesterol-herbal essential oil-hypocholesterolemic effect
    Food science and biotechnology 19(1):219-227. · 0.70 Impact Factor
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    ABSTRACT: Intake of saturated and trans-fatty acids is a strong risk factor for coronary heart disease. We investigated the inhibitory effects of 2 hexane extracts from white (WBE) and black soybeans (BBE) on cellular fatty acid uptake in vitro. Transcellular uptake of elaidic acid (t18:1), a major trans-fatty acid present in processed foods, in Caco-2 monolayers was significantly reduced by 28.3 and 16.7% 60 min after WBE and BBE treatment, respectively. Results of flow cytometry (FACS) analysis showed significant reductions in boron-dipyrromethene (BODIPY) fluorescence-labeled fatty acid uptake by 35.4 and 40.2% with WBE and BBE treatment, respectively. BBE treatment significantly reduced the expression of fatty acid transport protein-4 and CD36 in Caco-2 cells, as determined by quantitative real time-polymerase chain reaction (qRT-PCR). Similar trends were found in WBE treatment, although to a lesser degree. These observations suggest that soybean extract may reduce fatty acid uptake and cellular fat accumulation by altering fatty acid transporter expression. Keywordssoybean–fatty acid uptake–fatty acid transport protein-4–CD-36
    Food science and biotechnology 20(1):237-242. · 0.70 Impact Factor