• Journal of Veterinary Science
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• v.22 no.6
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• pp.92.1-92.12
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• 2021

Background: Naringin and its aglycone naringenin are citrus-derived flavonoids with several pharmacological effects. On the other hand, the mechanism for the anti-diabetic effects of naringenin and naringin are controversial and remain to be clarified further. Objective: This study examined the relationship between glucose uptake and AMP-activated protein kinase (AMPK) phosphorylation by naringenin and naringin in high glucose-treated HepG2 cells. Methods: Glucose uptake was measured using the 2-NBDG fluorescent D-glucose analog. The phosphorylation levels of AMPK and GSK3β (Glycogen synthase kinase 3 beta) were observed by Western blotting. Molecular docking analysis was performed to evaluate the binding affinity of naringenin and naringin to the γ-subunit of AMPK. Results: The treatment with naringenin and naringin stimulated glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells. Both flavonoids increased glucose uptake by promoting the phosphorylation of AMPK at Thr172 and increased the phosphorylation of GSK3β. Molecular docking analysis showed that both naringenin and naringin bind to the γ-subunit of AMPK with high binding affinities. In particular, naringin showed higher binding affinity than the true modulator, AMP with all three CBS domains (CBS1, 3, and 4) in the γ-subunit of AMPK. Therefore, both naringenin and naringin could be positive modulators of AMPK activation, which enhance glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells. Conclusions: The increased phosphorylation of AMPK at Thr172 by naringenin and naringin might enhance glucose uptake regardless of insulin stimulation in high glucose treated HepG2 cells.

• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.33-37
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• 2012

Differential capacity of the parthenogenetic embryonic stem cells (PESCs) is still under controversy and the mechanisms of its neural induction are yet poorly understood. Here we demonstrated neural lineage induction of PESCs by addition of insulin-like growth factor-2 (Igf2), which is an important factor for embryo organ development and a paternally expressed imprinting gene. Murine PESCs were aggregated to embryoid bodies (EBs) by suspension culture under the leukemia inhibitory factor-free condition for 4 days. To test the effect of exogenous Igf2, 30 ng/ml of Igf2 was supplemented to EBs induction medium. Then neural induction was carried out with serum-free medium containing insulin, transferrin, selenium, and fibronectin complex (ITSFn) for 12 days. Normal murine embryonic stem cells derived from fertilized embryos (ESCs) were used as the control group. Neural potential of differentiated PESCs and ESCs were analyzed by immunofluorescent labeling and real-time PCR assay (Nestin, neural progenitor marker; Tuj1, neuronal cell marker; GFAP, glial cell marker). The differentiated cells from both ESC and PESC showed heterogeneous population of Nestin, Tuj1, and GFAP positive cells. In terms of the level of gene expression, PESC showed 4 times higher level of GFAP expression than ESCs. After exposure to Igf2, the expression level of GFAP decreased both in derivatives of PESCs and ESCs. Interestingly, the expression level of $Tuj1$ increased only in ESCs, not in PESCs. The results show that IGF2 is a positive effector for suppressing over-expressed glial differentiation during neural induction of PESCs and for promoting neuronal differentiation of ESCs, while exogenous Igf2 could not accelerate the neuronal differentiation of PESCs. Although exogenous Igf2 promotes neuronal differentiation of normal ESCs, expression of endogenous $Igf2$ may be critical for initiating neuronal differentiation of pluripotent stem cells. The findings may contribute to understanding of the relationship between imprinting mechanism and neural differentiation and its application to neural tissue repair in the future.

• The Journal of Pediatrics of Korean Medicine
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• v.21 no.1
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• pp.253-270
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• 2007

Objectives : This study has been carried out to understand the effect of Cimicifugae Rhizoma and Seungmagalgeuntang on the hyperglycemic mice induced with Streptozotocin(STZ). Methods : The 60mg/kg of STZ was fed into mice twice by 24 h interval and then 120mg/kg STZ was fed again 3 days after the earlier feeding, Control group was administered mice with 0.9% saline(2mL/kg/day), and experimental groups were administered Cimicifugae Rhizoma extract(CA group, 10mg/kg/day; CB group, 30mg/kg/day) or Seungmagalgeuntang(SA group, 10mg/kg/day; SB group, 30mg/kg/day) after hyperglycemic induction for 6 weeks. Results : The body weight of experimental groups higher than control. The blood glucose concentration of the control group increased continuously reaching to 298.9 mg/dL after 6 weeks, however, significantly(p<0.01 or p<0.05) decreased in the SA and SB groups compared with control group. Blood insulin level significantly(p<0.01) increased in the experimental groups. The activities of SOD and catalase were more decreased in the experimental group than control group compared with normal group. In the point of pancreatic immunohistochemical change, the experimental group's pancreatic islets have increased and enlarged and the concentration of insulin-positive beta cells has also increased, comparing with the control group. Meanwhile forms of nucleus and mitochondria in the experimental group's hepatic cells were almost similar to the normal group. Conclusion : The result from the six weeks of observation demonstrates that the extracts from Cimicifugae Rhizoma and Seungmagalgeuntang have positive effects on lowering blood sugar level and elevating insulin concentration. The extract had also effects on recovering and regenerating pancreatic tissue of the hyperglycemic mice induced with STZ. At the same time, it had a protective effect against hepatotoxicity as well.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.12-47
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• 2005

First, mice were dosed with 50mg/kg of streptozotocin(STZ) twice every 24 hours to cause high blood-sugar. Then, after three days, mice were injected with 100mg/kg of STZ again. Two different dosages of Saengjihwangeumja-gami were given to the experiment groups: SA group, 15mg/kg/day, and SB group, 90mg/kg/day, in order to determine the effects of Saengjihwangeumja-gami, which has been known to be good for DM(Diabetes Mellitus). By observing weight and blood-sugar level changes, blood tolerance, the numerical value of BUN(Blood Urea Nitrogen) and creatinine in blood, and through light-electronicmicroscopic and immunohistologic investigations of pancreas and kidneys, the following results were obtained: 1. The experiment groups showed a high suppressive effect of weight-loss. 2. The experiment groups' blood-sugar and blood tolerance showed an effective lowering of blood-sugar levels. 3. The experiment groups did not show any noticeable change in the numerical value of BUN and creatinine in blood compared with that of the control groups. 4. The experiment groups showed a higher Insulin positive reaction of pancreatic islets ${/beta}-cell$ than the control groups. 5. The experiment groups showed a higher immuno-reaction against IGF- II than the control groups. 6. Observation of apoptosis of the pancreatic islets showed that the cells of experiment groups were less injured compared with those of the control groups, and fewer apoptag-positive reaction cells were seen in experiment groups than in the control groups. 7. Uunder electron-microscopy, the insulin-containing granules in pancreatic islets ${/beta}-cells$ had increased more in the experiment groups than in the control groups. 8. Under light microscopy, the injury on the inner & outer membrane of the glomerulus and epithelial cells of capillaries and cells among vessels were fewer in the experiment groups than in the control groups. 9. More apoptag-positive reaction cells in the kidney were seen in the control groups than in the experiment groups. 10. PAS-positive reaction substances had increased more in the substrate among the vessels of a glomerulus belonging to the control group than those of the experiment group. 11. Uunder electron-microscopy, the nucleonic membrane, nucleoplasm and mitochondria of proximal and distal renal tubular were more injured in the control groups than in the experiment groups. In conclusion, strong evidence for the efficacy of Saengjihwangeumja-gami in lowering blood-sugar, and in recovery and generation of pancreatic tissues injured by DM was observed. Results suggest Saengjihwangeumja-gami is an effective treatment for DM. Further study of the principles of blood-sugar dropping effects of Saengjihwangeumja-gami are needed, as well as further study of recovery and regeneration of pancreatic tissues injured by DM.

• Archives of Pharmacal Research
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• v.20 no.4
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• pp.297-305
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• 1997

A new serum-free defined medium was developed that supports the growth of normal rat mammary epithelial cells. Mammary organoids from the glands of female F344 rats were cultured in a serum-free medium. Monolayer culture colonies developed within a week and remained viable for months in culture. Upon subculture of one-week-old primary colonies, almost the same morphology of colonies was developed. The scrape loading/dye transfer technique showed that most of colonies that developed in a serum-free medium containing EGF, human transferrin, insulin, and hydrocortisone (basal serum-free medium, BSFM) failed to show cell-cell communication. However, colonies cultured in BSFM supplemented with prolactin, $E_2$, and progesterone (complete hormone serum-free medium, CHSFM) showed cell-cell communication at 14 days of primary culture or of subculture. By flow cytometry with FITCPNA and PE-anti-Thy-1.1 monoclonal antibody, we distinguished four RMEC subpopulations in cultures in both media: Thy-1.1+ cells, PNA+ cells, cells negative to both reagents and cells positive to both reagents. It is likely that combined prolactin, cortisol, and insulin in CHSFM stimulate terminal differentiation of clonogenic cells.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.518-528
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• 1995

The immunohistochemical study has been performed on the distribution of receptors for various growth factors in the newly forming granulation tissues following the guided tissue regeneration procedures. Two specimens from 2 different patients were collected from the newly forming granulation tissues at 2 weeks following GTR procedures using Gore-tex menbrane and rubber dam, respectively. For immunohistochemical localization of each recptor, anti-platelet-derived growth factor $receptor-{\alpha}$, anti-platelet-derived growth factor $receptor-{\beta}$. anti-insulin-like growth factor receptor, anti-basic fibroblast growth factor receptor, anti-transforming growth $factor-{\beta}$ receptor and anti-fibronectin receptor were incubated onto the specimens as primary antibodies. After the reaction, FITC-conjugated second antibodies have been applied. When the total numbers of immunoreactive cells and the true positive cells were counted, there were high variability among receptors tested in the present study. The mean number of immunoreactive cells were highest in the case for anti-IFG-1 receptor. However the number of true positive cells were highest in the case for $TGF-{\beta}$ receptor. The present investigation indicated that the receptor for $TGF-{\beta}$ were stongly expressed in the newly forming granulation tissues following the guided tissue regeneration therapy.

• Korean Journal of Pharmacognosy
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• v.46 no.1
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• pp.78-83
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• 2015

This study was conducted to verify the potential of Allium hookeri to control glucose metabolism in a diabetes model. We fed the experimental diets (AL, AR, Dex) supplemented with the powder of leaf, root, or dextrin as a positive control, respectively at 3% of diet to the diabetic mice (C57BLKS/J, db/db) for 8 weeks. Control mice were fed with the diet supplemented with cornstarch (Cont) at 3% level of diet. At 8th week of feeding the diets, we measured body weight, blood glucose, HbA1c, and plasma insulin levels and conducted an oral glucose tolerance test (OGTT) and staining insulin immunoreactive cells in islets of pancreas. AL group treated with the leaf of A. hookeri showed significantly lower blood glucose and HbA1c levels, higher plasma insulin levels, and increased density of insulin immunoreactive cells compared with the Cont group. During the OGTT, AL group showed lower blood glucose levels than the Cont group for 120 min. Based on these results, leaf of A. hookeri is considered to be effective in improving glucose tolerance by partially affecting insulin secretion and it may be used to prevent and treat diabetic disease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.632-637
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• 2005

This study has been carried out to understand the effect of Hovenia dulcis on the hyperglycemic mice induced with streptozotocin (STZ). Mice in control group were administered with $0.9\%$ saline (2 mL/kg), and experimental groups were administered Hovenia dulcis extract (H1 group, 0.01 g/kg: H2 group, 0.04 g/kg) after hyperglycemic state was induced. Blood glucose concentrations of tile H1 and H2 groups administered with Hovenia dulcis extract for 6 weeks were significantly (p<0.01), compared to control group. Blood glucose tolerance was more favorable in H1 and H2 groups than control group. The Langerhan's islet of pancreas was destructed by treatment of STZ in the control group, but pancreatic islet of the experimental groups was partially recovered from damage, and a number of insulin-positive cells were observed. A number of insulin-like growth factor- I and II (IGF-I and IGF-II) positive cells occurred in the acinar cells of H1 and H2 groups. These results suggest that administration of Hovenia dulcis extract help mice recover from the damage induced with STZ.

• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.1983-1990
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• 2007

Antidiabetic effects of a novel microbial biopolymer (PGB) 1 excreted from new Enterobacter sp. BL-2 were tested in the db/db mice. The animals were divided into normal control, rosiglitazone (0.005%, wt/wt), low PGB1 (0.1%, wt/wt), and high PGB1 (0.25%, wt/wt) groups. After 5 weeks, the blood glucose levels of high PGB1 and rosiglitazone supplemented groups were significantly lower than those of the control group. In hepatic glucose metabolic enzyme activities, the glucokinase activities of PGB1 supplemented groups were significantly higher than the control group, whereas the PEPCK activities were significantly lower. The plasma insulin and hepatic glycogen levels of the low and high PGB1 supplemented groups were significantly higher compared with the control group. Specifically, the insulin and glycogen increases were dose-responsive to PGB1 supplement. PGB1 supplement did not affect the IPGTT and IPITT compared with the control group; however, rosiglitazone significantly improved IPITT. High PGB1 and rosiglitazone supplementation preserved the appearance of islets and insulin-positive cells in immunohistochemical photographs of the pancreas compared with the control group. These results demonstrated that high PGB1 (0.25% in the diet) supplementation seemingly contributes to preventing the onset and progression of type 2 diabetes by stimulating insulin secretion and enhancing the hepatic glucose metabolic enzyme activities.

• The Journal of Korean Medicine
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• v.36 no.1
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• pp.75-85
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• 2015

Objectives: Type 2 diabetes mellitus is a metabolic disease characterized by insulin resistance and high blood glucose level from progressive insulin secretory defect. The rhizome of Atractylodes japonica Koidz. (AJ) has been used for treatment of retention of water in oriental medicine. The aim of this study is to examine the effects of AJ on type 2 diabetes rats. Methods: Type 2 diabetes was induced by 60% high fat diet and low dose streptozotocin. Rats were divided into 4 groups (n = 6); Nor (normal control group), Con (diabetic group treated with vehicle), Met (diabetic group treated with 200 mg/kg metformin) and AJ (diabetic group treated with 100 mg/kg AJ). The body weights and food intakes were measured during the treatment period. After 4 weeks treatment, blood glucose level, HOMA-IR, and protein expressions of IRS-1, p-IRS-1, PPAR-${\gamma}$, and GLUT4 were measured, and histopathological examination of beta cell was performed. Results: Compared with the control group, blood glucose level and HOMA-IR were reduced in rats treated with AJ. Impaired beta cells in pancreas of rats were recovered and phosphorylation of IRS-1 was increased in rats treated with AJ. And also, protein expressions of PPAR-${\gamma}$ and GLUT4 were increased by treatment of AJ. Conclusions: The results suggest that Atractylodes japonica Koidz. may have anti-diabetic effect on type 2 diabetic rats through regulation of blood glucose level and insulin resistance. Therefore Atractylodes japonica Koidz. may have positive effects on patients with type 2 diabetes.