• Title/Summary/Keyword: PTP

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Effects of Ginseng Berry Water Extract on the Polysaccharide Hydrolysis of Extracellular Enzymes and Intracellular PTP1B and AKT1 (진생베리 열수 추출물의 다당체 분해 효소와 인슐린 신호전달 분자 PTP1B와 AKT1에 미치는 효과)

  • Kwon, Eun-Jeong;Hong, Sugyeong;Kim, Moon-Moo;Kim, Joo Wan;Kim, Deok Won;Chung, Kyung Tae
    • Journal of Life Science
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    • v.24 no.9
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    • pp.1006-1011
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    • 2014

  • Ginseng has been known to be highly effective for health as a traditional medicinal herb. Ginseng berry, or fruit of ginseng, contains ginsenoside, saponin, polyphenol, polyacetylene, alkaloid, etc. as the main compounds as does ginseng. The aim of this study is to evaluate any effect of ginseng berry water extract (GBE) on diabetic-associated molecules, such as enzymes, which are responsible for the glucose entry of the cells and the insulin receptor signaling molecules using HepG2 cells. Therefore, two enzymes, ${\alpha}$-amylase and ${\alpha}$-glucosidase, were selected and assayed for their activities in the presence of GBE in vitro. These two enzymes are responsible for producing glucose from dietary starch. Protein-tyrosine phosphatase 1B (PTP1B) and Akt1 are key proteins in the insulin receptor signaling pathway. These two intracellular signaling molecules were investigated for their expression levels in HepG2 cells after insulin and GBE treatment. GBE, at concentrations up to $1,000{\mu}g/ml$, did not exert any inhibitory effect on ${\alpha}$-amylase and ${\alpha}$-glucosidase. It was observed that the expression level of PTP1B was increased by insulin and the $25{\mu}g/ml$ GBE treatment enhanced the PTP1B level. However, GBE at a concentration of $200{\mu}g/ml$ reduced the expression level of PTP1B. In the case of Akt1, the Akt1 level by insulin was decreased by GBE treatment. These data suggest that the water extracts of ginseng berry have an influence on intracellular signaling by insulin.

  • https://doi.org/10.5352/JLS.2014.24.9.1006 인용 PDF KSCI KPUBS HTML

Protein Tyrosine Phosphatase 1B inhibitory Activity of Anthraquinones and Stilbenes

  • Na, Min-Kyun;Jin, Wen Yi;Min, Byung-Sun;Ahn, Jong-Seog;Bae, Ki-Hwan
    • Natural Product Sciences
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    • v.14 no.2
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    • pp.143-146
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    • 2008

  • Protein tyrosine phosphatase 1B (PTP1B) is emerging as a potential therapeutic target for the treatment of type-2 diabetes and obesity. To search for new types of PTP1B inhibitors, we have undertaken in vitro enzyme assay for some anthraquinones and stilbenes isolated from plants. Of the anthraquinones tested, physcion (1), 1-O-methylemodin (2), and emodin (3) showed high activities, with $IC_{50}$ values of 7.6, 7.0, and $3.8{\mu}g/mL$, respectively, while the anthraquinone glycosides, physcion-8-O-${\beta}$-D-glucopyranoside (4) and emodin-8- O-${\beta}$-D-glucopyranoside (5), were less active than their aglycones. All the stilbenens (6 - 15) slightly inhibited PTP1B activity at high concentration of $30{\mu}g/mL$. Our findings suggest that the hypoglycemic effect of anthraquinones may be associated with their PTP1B inhibitory activity.

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Anti-obesity and hypolipidemic effects of Rheum undulatum in high-fat diet-fed C57BL/6 mice through protein tyrosine phosphatase 1B inhibition

  • Lee, Woo-Jung;Yoon, Goo;Hwang, Ye-Ran;Kim, Yong-Kee;Kim, Su-Nam
    • BMB Reports
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    • v.45 no.3
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    • pp.141-146
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    • 2012

  • Protein tyrosine phosphatase 1B (PTP1B) is important in the regulation of metabolic diseases and has emerged as a promising signaling target. Previously, we reported the PTP1B inhibitory activity of Rheum undulatum (RU). In the present study, we investigated the metabolic regulatory effects of RU in a high-fat diet (HFD) model. RU treatment significantly blocked body weight gain, which was accompanied by a reduction of feed efficiency. In addition, it led to a reduction of liver weight mediated by overexpression of PPAR${\alpha}$ and CPT1 in the liver, and an increase in the expression of adiponectin, aP2, and UCP3 in adipose tissue responsible for the reduction of total and LDL-cholesterol levels. Chrysophanol and physcion from RU significantly inhibited PTP1B activity and strongly enhanced insulin sensitivity. Altogether, our findings strongly suggest that 2 compounds are novel PTP1B inhibitors and might be considered as anti-obesity agents that are effective for suppressing body weight gain and improving lipid homeostasis.

  • https://doi.org/10.5483/BMBRep.2012.45.3.141 인용 PDF KSCI