The Herbal Composition Gangjihwan from Ephedra intermedia, Lithospermum erythrorhizon and Rheum palmatum Ameliorates Hepatic Inflammation and Fibrosis in Obese C57BL/6J Mice and HepG2 Cells

Michung Yoon 대한의생명과학회 2017 Biomedical Science Letters Vol.23 No.2

It was demonstrated that Gangjihwan (DF), which is the herbal composition composed of Ephedra intermedia, Lithospermum erythrorhizon, and Rheum palmatum, inhibits obesity and hepatic steatosis in high fat diet (HFD)-fed obese mice. The aim of this study was to determine the effects of DF on visceral obesity, hepatic inflammation and fibrosis and the mechanism of actions involved in this process using in vivo and in vitro approaches. DF was extracted with water (DF-FW), 30% grain alcohol (DF-GA30), and 70% grain alcohol (DF-GA70). Administration of DF to HFD-fed control mice decreased visceral tissue mass and visceral adipocyte size without adverse effects. Visceral fat mass was decreased by DF-GA30 and DF-GA70, and visceral adipocyte size by all three DF extracts compared with obese control mice. Histological analysis revealed that three kinds of DF extracts reduced toluidine blue-stained mast cells and collagen accumulation in the liver, the extents of which were most eminent in DF-GA70-treated mice. DF-GA70 decreased the mRNA levels of the inflammation (TNFα and VCAM-1), fibrosis (α-SMA), and apoptosis (caspase 3) genes, but increasing the anti-apoptosis gene (Bcl-2) mRNA levels in the liver of obese control mice. Consistent with the in vivo data, GA-70 also altered the expression of inflammation genes (TNFα and MCP-1) in HepG2 cells. These results indicate that DF not only inhibits visceral obesity, but also ameliorates visceral obesity-induced hepatic inflammation and fibrosis and that this process may be mediated by regulating the hepatic expression of inflammatory and fibrogenic genes.

The Role of Angiogenesis in Obesity

Michung Yoon(윤미정) 한국생명과학회 2014 생명과학회지 Vol.24 No.5

혈관신생은 모든 조직의 성장과 발달, 그리고 상처회복 등에 매우 중요하다. 지방조직은 우리 몸에서 가장 혈관이 발달된 조직으로서 각 지방세포들은 모세혈관에 둘러싸여 있으며 신생혈관들은 지방세포에 영양분과 산소를 공급한다. 혈관의 내피세포들은 파라크린 신호경로, 세포외 성분, 세포들 간의 직접적인 작용을 통해 지방세포와 교류한다. 활성화된 지방세포들은 VEGF, FGF-2, leptin, HGF와 같은 혈관신생인자들을 생성하며, 이들은 단독으로 혹은 협력하여 혈관신생을 증가시키고 지방조직의 성장과 대사를 촉진한다. 따라서 혈관신생 억제제들은 비만과 비만관련 질환을 치료하는데 유용할 것으로 생각된다. Angiogenesis, the formation of new capillary blood vessels, is a tightly regulated process. Under normal physiological conditions, angiogenesis only takes place during embryonic development, wound healing, and female menstruation. Dysregulation of angiogenesis is associated with many diseases, such as cancer, rheumatoid arthritis, psoriasis, and proliferative retinopathy. The growth and expansion of adipose tissue require the formation of new blood vessels. Adipose tissue is probably the most highly vascularized tissue in the body, as each adipocyte is surrounded by capillaries, and the angiogenic vessels supply nutrients and oxygen to adipocytes. Accumulating evidence shows that capillary endothelial cells communicate with adipocytes via paracrine signaling pathways, extracellular components, and direct cell-cell interactions. Activated adipocytes produce multiple angiogenic factors, including VEGF, FGF-2, leptin, and HGF, which either alone or cooperatively stimulate the expansion and metabolism of adipose tissue by increasing adipose tissue vasculature. Recently, it was demonstrated that antiangiogenic herbal Ob-X extracts and Korean red ginseng extracts reduce adipose tissue mass and suppress obesity by inhibiting angiogenesis in obese mice. Thus, angiogenesis inhibitors provide a promising therapeutic approach for controlling human obesity and related disorders.

사람의 혈중 아포지단백질 A-1(apo A-1) 측정을 위한 경쟁적 효소면역 분석법 (ELISA) 의 개발

Michung Yoon,Ju Won Kwak,Moon Hi Han 한국지질동맥경화학회 1993 韓國脂質學會誌 Vol.3 No.1

Repression of PPARγ Activity on Adipogenesis by 17β-estradiol in Differentiated 3T3-L1 Cell

Michung Yoon,Sunhyo Jeong 대한의생명과학회 2009 Biomedical Science Letters Vol.15 No.3

In our previous report, we showed that PPARγ does not influence adipogenesis in females with functioning ovaries, indicating that PPARγ activity on adipogenesis is associated with sex-related factors. Among the sex-related factors, estrogen has been recognized as a major factor in inhibiting adiposgenesis in females. Thus, we hypothensized that 17β-estradiol (E) inhibits 3T3-L1 cell adipogenesis by preventing PPARγ activity. E decreased triglyceirde accumulation in differentiated 3T3-L1 cells compared with control group. E also decreased the expression of PPARγ mRNA as well as PPARγ dependent adipocyte-specific genes, such as adipocyte fatty acid binding protein and tumor necrosis factor α. In addition, E not only decreased luciferase reporter activity by PPARγ, but also transfection of estrogen receptor α (ERα) or ERβ led to decreases in PPARγ reporter gene activation. Moreover, E-activated ERs significantly decreased the luciferase reporter gene activation induced by PPARγ transfection, suggesting that estrogen-activated ERs inhibit PPARγ-dependent transactivation. Accordingly, our results demonstrate that E inhibits the action of PPARγ on adipogenesis through E activated ER, providing evidence that lack of estrogen may potentiate PPARγ action on adipogenesis.

17β-estradiol Prevents the Expression of CEBPα-mediated Adipocyte Marker Genes in Female Ovariectomized C57BL/6 Mice

Michung Yoon,Sunhyo Jeong 대한의생명과학회 2008 Biomedical Science Letters Vol.14 No.3

Adipogenesis is a complex sequence of events that culminates in the differentiation of fibroblast-like preadipocytes into specialized lipid-filled adipocytes and also involves a cascade of expression of many transcription factors such as peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding proteins (C/EBPs). PPARγ and C/EBPs transcriptionally transactivate adipocyte specific genes, including fatty acid transport protein (FAT/CD36) and leptin. To determine whether 17β-estradiol modulates C/EBPα actions on adipogenesis in high fat diet-fed female ovariectomized (OVX) C57BL/6 mice, mice were treated with 17β-estradiol for 7 days and the effects of 17β-estradiol on adipose tissue mass and expression of adipocyte specific gene as well as C/EBPα were measured. Compared to vehicle-treated OVX control mice, OVX mice treated with 17β-estradiol for 7 days had lower adipose tissue weights that were similar to weights in high fat diet-fed sham-operated (Sham) mice. OVX mice showed the increased expression of C/EBPα mRNA compared with Sham mice. However, 17β-estradiol treatment in OVX mice inhibited OVX induced-C/EBPα activation, indicating that 17β-estradiol may act as an inhibitor of C/EBPα action. Moreover, 17β-estradiol decreased mRNA levels of adipocyte marker genes, such as lipoprotein lipase, FAT/CD36 and leptin, to levels in Sham mice. These results suggest that down-regulation of adipogenesis by 17β-estradiol may be due to reduced adipose C/EBPα activities in female OVX C57BL/6 mice.

Measurement of the Affinity Constant of Monoclonal Antibody to Human Apolipoprotein A-I by ELISA

Michung Yoon(윤미정),Hyun-Hee Lee(이현희) 대한의생명과학회 1995 Biomedical Science Letters Vol.1 No.1

본 연구에서는 효소면역진단법을 이용하여 사람의 아포지단백질 A-I에 대한 단일클론항체의 해리상수(Kd)를 측정하고자 하였다. 먼저 단일클론항체와 항원을 평형에 도달할 때까지 액체상에서 반응시킨 후, 평형상태에서 항원과 결합하지 못하고 남아있는 항체를 미세적정판에 결합되어 있는 항원과 반응시킨다. 그 다음 결합된 항체의 양이 효소면역분석법에 의하여 측정한다. 본 실험방법을 이용하여 측정된 아포지단백질 A-I에 대한 단일클론항체의 해리상수는 정제된 형태의 경우 0.625×10??이었으며, 정제되지 않은 하이브리도마 배양액의 경우 0.720×10??이었다. 이 방법은 간단하고 재생성이 높으며, 정확하고 방사선 동위원소를 사용하지 않는 등 많은 장점을 가진 것으로 생각된다. The present study was undertaken to determine the dissociation constant (Kd) of monoclonal antibody to human apolipoprotein A-I (apo A-I) using enzyme-linked immunosorbent assay (ELISA). First the monoclonal antibody was incubated in solution with the antigen until the equilibrium was reached; then the free antibody which remains unsaturated at equilibrium was captured by binding to antigen on the micro titer plate and be measured by a classical indirect ELISA. The value of Kd determined from Scatchard plot was 0.625×10?? for purified antibody and 0.720×10?? for unpurified antibody. This method was valuable for the measurement of true dissociation constant and found to be simple, reproducible, and accurate.

The Korean Traditional Medicine Gyeongshingangjeehwan Reduces Lipid Accumulation in Skeletal Muscle and C2C12 Cells

Michung Yoon 대한의생명과학회 2011 Biomedical Science Letters Vol.17 No.4

Our previous study demonstrated that the Korean traditional medicine Gyeongshingangjeehwan (GGEx) activates AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor α (PPARα) critical for fatty acid oxidation in skeletal muscle and C2C12 skeletal muscle cells. Thus, we examined whether GGEx can reduce lipid accumulation in these cells and tissues. After obese and type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats were treated with GGEx, we studied the effects of GGEx on skeletal muscle lipid accumulation. The effects of GGEx and/or the AMPK inhibitor compound C on lipid accumulation and expression of AMPK and PPARα were measured in C2C12 skeletal muscle cells. Compared with lean Long-Evans Tokushima Otsuka rats, obese OLETF rats had increased triglyceride droplets. However, administration of GGEx to OLETF rats for 8 weeks significantly decreased triglyceride droplets in skeletal muscle. Consistent with the in vivo data, GGEx inhibited lipid accumulation, the degree of which was comparable to Wy14,643, the potent activator of PPARα. GGEx also increased skeletal muscle mRNA levels of AMPKα1, AMPKα2, and PPARα. However, compound C inhibited these effects in C2C12 cells. These results suggest that GGEx suppresses skeletal muscle lipid accumulation and this process may be mediated by AMPK and PPARα activation.

Peroxisome Proliferator-activated Receptor γ Is Not Associated with Adipogenesis in Female Mice

Michung Yoon,Sunhyo Jeong 대한의생명과학회 2008 Biomedical Science Letters Vol.14 No.3

The peroxisome proliferator-activated receptor γ (PPARγ) plays a central role in adipogenesis and lipid storage. The PPARγ ligands, thiazolidinediones (TZDs), enhance in vitro adipogenesis in several cell types, but the role of the TZDs on in vivo adipogenesis is still poorly understood. To investigate how PPARγ ligand troglitazone regulates adipogenesis in female mice, we examined the effects of the troglitazone on adipose tissue mass, morphological changes of adipocytes, and the expression of PPARγ target and adipocyte-specific genes in low fat diet-fed female C57BL/6 mice. Administration of troglitazone for 13 weeks did not change body and total white adipose tissue weights compared with control mice. Troglitazone treatment also did not cause a significant decrease in the average size of adipocytes in parametrial adipose tissue although it is reported to increase the number of small adipocytes in male animals. Troglitazone did not affect the mRNA expression of PPARγ and its target genes as well as adipocyte-specific genes in parametrial adipose tissue. These results suggest that PPARγ does not seem to be associated with adipogenesis in females with functioning ovaries and that its inability to induce adipogenesis may be due to sex-related factors.

Development of a Competitive Enzyme-Linked Immunoassay for Human Apolipoprotein B

Michung Yoon,Ju Won Kwak,Moon Hi Han 한국지질동맥경화학회 1993 韓國脂質學會誌 Vol.3 No.1

17β-estradiol Represses White Adipose Tissue Metabolism by Inhibiting PPARγ in High Fat Diet-induced Obese Female Ovariectomized Mice

Michung Yoon,Sunhyo Jeong 대한의생명과학회 2009 Biomedical Science Letters Vol.15 No.3

This study investigated whether increased adiposity is prevented by estrogen replacement in female ovariectomized (OVX) C57BL/6J mice, an animal model of human menopause and whether these metabolic changes reflect the inhibitory action of estrogen on peroxisome proliferator-activated receptor γ (PPARγ)-regulated gene expression. Treatment of 17β-estradiol for the last one week of the experiment decreased high fat diet-induced body weight gain and white adipose tissue mass compared to OVX control mice. Histological analysis showed that administration of 17β-estradiol to mice decreased the size of adipocytes in parametrial adipose tissue versus OVX control mice. In addition, 17β-estradiol reduced the adipose expression of PPARγ as well as PPARγ target genes such as adipocyte fatty acid binding protein and tumor necrosis factor α. These results suggest that 17β-estradiol may inhibit adiposity through reducing the PPARγ activities in female OVX mice.