• Korean Journal of Poultry Science
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• v.43 no.1
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• pp.47-54
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• 2016

The aim of this study was to investigate the expression patterns of key genes involved in lipid metabolism in response to dietary Coenzyme Q10 (CoQ10) in hens. A total of 36 forty week-old Lohmann Brown were randomly allocated into 3 groups consisting of 4 replicates of 3 birds. Laying hens were subjected to one of following treatments: Control (BD, basal diet), T1 (BD+ CoQ10 100 mg/kg diet) and T2 (BD+ micellar of CoQ10 100 mg/kg diet). Birds were fed ad libitum a basal diet or the basal diet supplemented with CoQ10 for 5 weeks. Total RNA was extracted from the liver for quantitative RT-PCR. The mRNA levels of HMG-CoA reductase(HMGCR) and sterol regulatory element-binding proteins(SREBP)2 were decreased more than 30~50% in the liver of birds fed a basal diet supplemented with CoQ10 (p<0.05). These findings suggest that dietary CoQ10 can reduce cholesterol levels by the suppression of the hepatic HMGCR and SREBP2 genes. The gene expressions of liver X receptor (LXR) and SREBP1 were down regulated due to the addition of CoQ10 to the feed (p<0.05). The homeostasis of cholesterol can be regulated by LXR and SREBP1 in cholesterol-low-conditions. The supplement of CoQ10 caused a decreased expression of lipid metabolism-related genes including $PPAR{\gamma}$, XBP1, FASN, and GLUTs in the liver of birds (p<0.05). These data suggest that CoQ10 might be used as a dietary supplement to reduce cholesterol levels and to regulate lipid homeostasis in laying hens.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.806-813
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• 2013

Agrimonia pilosa Ledeb. is a medicinal plant with anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic activities. However, few studies of the anti-diabetic effect of A. pilosa on insulin resistance status have been performed. In the present study, the anti-diabetic effect of A. pilosa water extract (AP) was determined by investigating its ${\alpha}$-glucosidase inhibitory property, glucose utilization, and uptake, as well as insulin resistance mechanism of action in C2C12 skeletal muscle cells. Compared to positive control (acarbose), AP ($10mg/m{\ell}$) showed a similar ${\alpha}$-glucosidase inhibitory capacity. Glucose uptake was significantly increased by $1{\mu}m$ insulin treatment (p<0.05). However, palmitic acid (FFA, 1 mM) induced muscle insulin resistance and glucose uptake dysfunction. On the other hand, AP ($10{\mu}g/m{\ell}$) was capable of reversing the FFA-induced insulin resistance in C2C12 myotubes. Compared to control, AP ($100{\mu}g/m{\ell}$ without insulin) significantly increased the utilization of glucose (p<0.05) in C2Cl2 myotubes cultured in normal glucose (7 mM). AP treatment significantly increased the relative mRNA and protein expression levels of Akt. In particular, the effect of A. pilosa on the insulin signaling system is associated with the up-regulation of Akt genes and glucose uptake in C2Cl2 myotubes. These results suggest that A. pilosa is useful in the prevention of diabetes and the treatment of hyperglycemic disorders.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.2
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• pp.178-188
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• 2013

The glycosaminoglycans (GAGs) present in the female reproductive tract promote sperm capacitation. When bovine sperm were exposed to 10 ${\mu}g/ml$ of one of four GAGs (Chondroitin sulfate, CS; Dermatan sulfate, DS; Hyaluronic acid, HA; Heparin, HP) for 5 h, the total motility (TM), straight-line velocity (VSL), and curvilinear velocity (VCL) were higher in the HP- or HA-treated sperm, relative to control and CS- or DS-treated sperm. HP and HA treatments increased the levels of capacitated and acrosome-reacted sperm over time, compared to other treatment groups (p<0.05). In addition, sperm exposed to HP or HA for 1 h before IVF exhibited significantly improved fertilizing ability, as assessed by 2 pronucleus (PN) formation and cleavage rates at d 2. Exposure to these GAGs also enhanced in vitro embryo development rates and embryo quality, and increased the ICM and total blastocyst cell numbers at d 8 after IVF (p<0.05). A real-time PCR analysis showed that the expression levels of pluripotency (Oct 4), cell growth (Glut 5), and anti-apoptosis (Bax inhibitor) genes were significantly higher in embryos derived from HA- or HP-treated sperm than in control or other treatment groups, while pro-apoptotic gene expression (caspase-3) was significantly lower in all GAG treatment groups (p<0.05). These results demonstrated that exposure of bovine sperm to HP or HA positively correlates with in vitro fertilizing ability, in vitro embryo developmental potential, and embryonic gene expression.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.60-60
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• 2003

Embryonic stem (ES) cells have property of self-renewal and can differentiate into the cells of all three primary germ layers. Recently, many growth factors, alteration of culture condition and gene modifications have been used to differentiate mouse and human ES cells into specific cell types. This study was performed to evaluate the differentiation protocol for human ES cells to the endodermal lineage cells. Human ES cells (Miz-hESl ) were cultured on STO feeder layer mitotically inactivated with mitemycin C, and embryoid bodies (EBs) were formed by suspension culture. Differentiation protocol of EBs consisted of three steps: stage I, culture of EBs for 6 days with ITSFn medium; stage II, culture of stage I cells for 8 days with N2 medium ; stage III, culture of stage II cells for 22 days with N2 medium. mRNA levels of the endodermal lineage differentiation genes were analyzed by semi- quantitative RT-PCR. The Oct-4 expression, a marker of the pluripotent state, was detected in undifferentiated human ES cells but progressively decreased after EBs formation. Differentiating human ES cells expressed marker genes of endodermal differentiation and pancreatic islet cells. GATA4, a-fetoprotein, Glut-2, and Ngn3 were expressed in all stages. However, albumin and insulin were expressed in only stage III cells. The human ES cells can be differentiated into endodermal lineage cells by multiple step culture system using various supplements. We are developing the more effective protocols for guided differentiation of human ES cells.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.1
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• pp.7-12
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• 2008

OLETF (Otsuka Long-Evans Tokushima Fatty) rats are characterized by obesity-related insulin resistance, which is a phenotype of type 2 diabetes. Sulfonylurea drugs or benzoic acid derivatives as inhibitors of the ATP-sensitive potassium $(K_{ATP})$ channel are commercially available to treat diabetes. The present study compared sulfonylurea drugs (glimepiride and gliclazide) with one of benzoic acid derivatives (repaglinide) in regard to their long-term effect on ameliorating insulin sensitivity in OLETF rats. Each drug was dissolved and fed with drinking water from 29 weeks of age. On high glucose loading at 45 weeks of age, response of blood glucose recovery was the greatest in the group treated with glimepiride. On immunohistochemistry analysis for the Kir6.2 subunit of $K_{ATP}$ channels, insulin receptor ${\beta}$-subunits, and glucose transporters (GLUT) type 2 and 4 in liver, fat and skeletal muscle tissues, the sulfonylurea drugs (glimepiride and gliclazide) were more effective than repaglinide in recovery from their decreased expressions in OLETF rats. From these results, it seems to be plausible that $K_{ATP}$-channel inhibitors containing sulfonylurea moiety may be much more effective in reducing insulin resistance than those with benzoic acid moiety. In contrast to gliclazide, non-tissue selectivity of glimepiride on $K_{ATP}$ channel inhibition may further strengthen an amelioration of insulin sensitivity unless considering other side effects.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.86-97
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• 2021

Background: Panax ginseng Meyer has been used as a nourishing edible herb in East Asia for thousands of years. 25-OH-PPT was first discovered as a natural rare triterpenoid saponin in ginseng stems and leaves by our group. Research found that it showed strong inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, and protected cardiocytes (H9c2) through PI3K/Akt pathway. Methods: In the research, in order to optimize the 25-OH-PPT enrichment process, optimal macroporous resins and optimal purification conditions were studied. Meanwhile, the hypoglycemic effect and mechanism of 25-OH-PPT were evaluated by using STZ to establish insulin-dependent diabetic mice and the spontaneous type 2 diabetes DB/DB mice. Results and Conclusion: Research found that 25-OH-PPT can reduce blood glucose and enhance glucose tolerance in STZ model mice. It increases insulin sensitivity by upregulating GLUT4 and AMPK in skeletal muscle, and activating insulin signaling pathways. In DB/DB mice, 25-OH-PPT achieves hypoglycemic effects mainly by activating the insulin signaling pathway. Meanwhile, through the influence of liver inflammatory factors and lipids in serum, it can be seen that 25-OH-PPT has obvious anti-inflammatory and lipid-lowering effects. These results provide new insights into the study of ginseng as a functional food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.324-330
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• 2015

In this study, the anti-diabetic activity of a cold water extract of Korean mistletoe (KME) was investigated in C57BL/6J Lep ob (ob/ob) mice. Oral administration of KME (50 or 100 mg/kg/d) significantly inhibited the level of blood glucose of ob/ob mice after 5 days from the beginning of KME treatment. And the anti-diabetic effect of KME was stabilized 10 days after oral administration, showing a substantial reduction of blood glucose levels by more than 20% as compared with control mice. The results of oral glucose tolerance test (OGTT) revealed that oral administration of KME gave rise to a remarkable improvement in overall glucose response. Oral administration of KME in ob/ob diabetic mice also significantly reduced blood total cholesterol (TCHO) and triglyceride (TG) levels compared with the diabetic control mice. Moreover, in an in vitro experiment using C2C12 myotubes, treatment of KME prominently increased glucose uptake. Interestingly, KME significantly increased the expression of peroxisome proliferator-activated receptor gamma coactivator 1-${\alpha}$ ($PGC-1{\alpha}$), a head regulator of mitochondrial biogenesis and oxidative metabolism, and $PGC-1{\alpha}$-associated genes such as glucose transporter type 4 (GLUT4), estrogen-related receptor-${\alpha}$ ($ERR-{\alpha}$), nuclear respiratory factor-1 (NRF-1), and mitochondrial transcription factor A (TmfA) in C2C12 cells. These results suggest that KME has potential as a novel therapeutic agent for diabetes, and its anti-diabetic activity may be related to the regulation of mitochondrial biogenesis.

• Journal of Life Science
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• v.31 no.2
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• pp.209-218
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• 2021

This study aimed to evaluate the anti-obesity effects of Cudrania tricuspidata leaf extract in the order of leaf development on the shoot (L0, L1, L2, L3, L4, and L5). The leaves at the apex of a Cudrania tricuspidata shoot were classified as L0; the next leaves of the apex were classified as L1, L2, L3, and L4 from highest to lowest; and the lowest leaf was classified as L5. A series of 70% ethyl alcohol leaf extracts were screened for the inhibitory effects of adipogenesis in 3T3-L1 preadipocytes. We found that the apical leaf extract of Cudrania tricuspidata (CTL0) was the most effective. Next, a study was conducted on the inhibitory action mechanism of CTL0. Treatment with CTL0 significantly suppressed the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner, as confirmed by the decrease in lipid droplet content observed with Oil Red O staining. Treatment with 12.5 ㎍/ml, 25 ㎍/ml, and 50 ㎍/ml of CTL0 significantly reduced the lipid droplet content. Glucose and cellular triglyceride concentrations were reduced in the 3T3-L1 cells on the CTL0-treated medium compared to the differentiation medium (DM control, DMEM + insulin + dexamethasone + rosiglitazone). Compared with DM, CTL0 significantly inhibited the expression of key pro-adipogenic transcription factors, including peroxisome proliferator-activated receptor γ (PPARγ), LPL, A-FABP, and Glut4. These findings show that CTL0 extract has potent anti-obesity effects.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.1
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• pp.54-60
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• 2016

Amomum cadamomum Linne (ACL) has long been utilized against the inhibited qi movement related diseases such as dyspepsia, acute gastroenteritis, vomiting and diarrhea in Korean medicine. We speculated that ACL could improve the metabolic disorders such as obesity and type 2 diabetes through removing the phlegm-dampness and promoting the qi movement or stagnation. This study was designed to investigate effects and molecular mechanisms of ACL extract on the improvement of adipocyte dysfunction induced by TNF-α in 3T3-L1 adipocytes. Potential roles of ACL extract in the lipogenesis, inhibition of inflammatory cytokines and insulin resistance, were investigated in this study. Also, we examined the adipose genes and signaling molecules related to insulin resistance and glucose uptake to elucidate its mechanism. Our data demonstrated that TNF-α significantly incresed the release of lipid droplets and the production of MCP-1 and IL-6 from adipocytes. In gene expression, TNF-α reduced the expression of aP2, PPARγ, C/EBPα, GLUT4, and IRS-1 related to lipogenesis and insulin sesitivity, while TNF-α increased the expression of MCP-1 related to inflammation. In addition, TNF-α down-regulated the PPARγ and IRS-1 protein and up-regulated the IRS-1 Ser307 phosphorylation. These alterations induced by TNF-α were prevented by the treatment of ACL extract. Thus, our results indicate that ACL extract can be used to prevent from the TNF-α-induced adipocyte dysfunction through insulin and PPARγ pathways.

• Journal of Ginseng Research
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• v.46 no.1
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• pp.39-53
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• 2022

Ginsenoside Rb₁ (Rb₁), one of the most important ingredients in Panax ginseng Meyer, has been confirmed to have favorable activities, including reducing antioxidative stress, inhibiting inflammation, regulating cell autophagy and apoptosis, affecting sugar and lipid metabolism, and regulating various cytokines. This study reviewed the recent progress on the pharmacological effects and mechanisms of Rb₁ against cardiovascular and nervous system diseases, diabetes, and their complications, especially those related to neurodegenerative diseases, myocardial ischemia, hypoxia injury, and traumatic brain injury. This review retrieved articles from PubMed and Web of Science that were published from 2015 to 2020. The molecular targets or pathways of the effects of Rb₁ on these diseases are referring to HMGB1, GLUT4, 11β-HSD1, ERK, Akt, Notch, NF-κB, MAPK, PPAR-γ, TGF-β1/Smad pathway, PI3K/mTOR pathway, Nrf2/HO-1 pathway, Nrf2/ARE pathway, and MAPK/NF-κB pathway. The potential effects of Rb₁ and its possible mechanisms against diseases were further predicted via Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and disease ontology semantic and enrichment (DOSE) analyses with the reported targets. This study provides insights into the therapeutic effects of Rb₁ and its mechanisms against diseases, which is expected to help in promoting the drug development of Rb₁ and its clinical applications.