• Title/Summary/Keyword: Anti-freeze

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Inhibitory Effects of Sasa borealis Leaves Extracts on Carbohydrate Digestive Enzymes and Postprandial Hyperglycemia (조릿대잎 추출문의 탄수화물 소화효소활성 저해 및 식후혈당강하효과)

  • Hwang, Ji-Young;Han, Ji-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.8
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    • pp.989-994
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    • 2007
  • This study was designed to investigate whether Sasa borealis leaves extracts (SLE) may inhibit yeast ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities and postprandial hyperglycemia in STZ-induced diabetic mice. Freeze-dried SLE was extracted with 70% methanol and followed by a sequential fractionation with dicholoromethan, ethylacetate, butanol, and water. Both ethylacetate and butanol fractions showed high inhibitory activities against the ${\alpha}-glucosidase$ and ${\alpha}-amylase$ enzymes. The $IC_{50}$ of ethylacetate and butanol fractions against ${\alpha}-glucosidase$ were 0.54 and 0.63 mg/mL, respectively, indicating a greater inhibition effect than acarbose (0.68 mg/mL) (p<0.05). Likewise, the two fractions exhibited a smaller $IC_{50}$ against ${\alpha}-amylase$, compared with acarbose (p<0.05). However, the yield of ethylacetate fraction of SLE was relatively small. Postprandial blood glucose testing of normal mice and STZ-induced diabetic mice by starch soln. loading (2 g/kg B.W.) showed that postprandial blood glucose level at 30, 60, and 120 min were markedly decreased by single oral administration of SLE butanol fraction (200 mg/kg B.W.) in both normal (p<0.0l) and diabetic mice (p<0.0l). Furthermore, the incremental area under the curve (AUC) was significantly lowered via SLE administration (5,745 versus 12,435 $mg{\cdot}mim/dL$) in the diabetic mice (p<0.0l). The incremental AUC in normal mice corroborated the hypoglycemic effect of SLE (p<0.0l) found in the diabetic mice. These results suggest that SLE may delay carbohydrate digestion and thus glucose absorption. In addition, SLE may have the potential to prevent and treat diabetes via its ability on lowering postprandial hyperglycemia.

Preventive Effects of Rosa rugosa Root Extract on Advanced Glycation End product-Induced Endothelial Dysfunction (해당근 추출물의 항산화 활성 및 최종당화산물에 의한 혈관내피세포 기능장애 억제활성)

  • Nam, Mi-Hyun;Lee, Hyun-Sun;Hong, Chung-Oui;Koo, Yoon-Chang;Seo, Mun-Young;Lee, Kwang-Won
    • Korean Journal of Food Science and Technology
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    • v.42 no.2
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    • pp.210-216
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    • 2010
  • Rosa rugosa has traditionally been used as a folk remedy for diabetes. The objective of this study was therefore to demonstrate the inhibition of endothelial dysfunction activities through antioxidants and the anti-glycation of Rosa rugosa roots. Dried roots of Rosa rugosa were boiled in methanol for three hours, evaporated and lyophilized with a freeze-dryer. The methanolic extract of Rosa rugosa roots (RRE) was tested for antioxidant activities by measuring total polyphenol (TP) content, flavonoid content, 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging activity (DPPH) assay, and ferric-reducing antioxidant power (FRAP) assay. The total TP content, flavonoid content, FRAP value, and $DPPHSC_{50}$ are $345.2\;{\mu}g$ gallic acid equivalents/mg dry matter (DM), $128.1\;{\mu}g$ quercetin equivalents/mg DM, 2.2 mM $FeSO_4$/mg DM and $34.2\;{\mu}g$ DM/mL, respectively. Treatment of RRE significantly lowered fluorescent formation due to advanced glycation reaction. In addition, reactive oxygen species (ROS) scavenging assay, monocyte adherent assay and transendothelial electrical resistance (TEER) assay were performed to investigate the possibility that RRE improves endothelial dysfunction-induced diabetic complications. The adhesion of THP-1 to treated HUVEC with RRE ($100\;{\mu}g/mL$; 33% and $500\;{\mu}g/mL$; 75%) was significantly reduced compared to HUVEC stimulated by glyceraldehydes-AGEs (advanced glycation end product). The TEER value ($88\;{\Omega}{\cdot}cm^2$) of stimulated HUVEC by glyceraldehydes-AGEs was reduced compared to non-stimulation ($113\;{\Omega}{\cdot}cm^2$). However, normalization with RRE increased endothelial permeability in a dose-dependent manner ($100\;{\mu}g/mL$; $102\;{\Omega}{\cdot}cm^2$ and $500\;{\mu}g/mL$; $106\;{\Omega}{\cdot}cm^2$). Thus, these results suggest that Rosa rugosa roots could be a novel candidate for the prevention of diabetic complications through antioxidants and inhibition of advanced glycation end product formation.

Multinational Enforcement of the Capital Markets Act - Focusing on the Anti-Fraud Regulation by the Public Regulators - (다국적 차원의 자본시장법규 집행 - 공적기관에 의한 불공정거래 규제를 중심으로 -)

  • Chang, Kun-Young
    • Journal of Legislation Research
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    • no.53
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    • pp.419-454
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    • 2017
  • Faced with the internationalization of capital markets, Korea needs to protect its investors and markets by applying the relevant laws extraterritorially. The Financial Investment Services and Capital Markets Act ("Capital Markets Act") explicitly introduced a new provision recognizing the extraterritoriality of the Act. While Article 2 of the Capital Markets Act comprehensively provides for prescriptive extraterritorial jurisdiction, the enactment of extraterritoriality alone does not guarantee that the Act will apply to cross-border transactions effectively. The effective extraterritorial application of an act is inseparable from the adjudicative and enforcement jurisdiction of the act. Specifically, active investigations and detections by the public regulators might be the first step for enforcing the Capital Markets Act. Unlike domestic regulations, however, multinational enforcement actions outside a regulator's home country becomes more problematic because of various obstacles. This Article examines difficulties which domestic regulators may confront in enforcing the Capital Markets Act extraterritorially and makes several recommendations for more effective multinational enforcement as follows. First, the Korean regulators should continue to foster cooperation through the IOSCO and provide international markets with the information and tools necessary for successful regulation of cross-border transactions. Second, the principle of dual criminality should be applied in a modified form for the effective mutual legal assistance in criminal matters. Third, there should be a legal device for the domestic regulator to freeze foreign wrongdoer's assets located outside Korea to repatriate those assets for distribution to defrauded investors in Korea.