• 한국가금학회지
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• 제40권2호
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• pp.147-155
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• 2013

본 연구는 육계에서 비타민 C와 E의 첨가 급여가 소포체(ER) 스트레스 및 지방 및 포도당대사 연관 유전자들의 발현에 미치는 영향을 살펴보고자 실시하였다. 육계에 비타민 첨가 급여 후 5주령에 닭의 간을 취하여 유전자들의 발현을 real-time PCR로 비교 분석하였다. 육계의 비타민 C 및 E 첨가 급여는 HSP70, HSP90 및 HMGCR 스트레스 마커 유전자들의 발현을 감소시켰다. ER 스트레스 관련 유전자들 또한 스트레스 마커 유전자들과 마찬가지로 비타민 처리에 의하여 대조구에 비하여 낮은 발현 양상을 보여줌으로서, 대표적 스트레스 마커 유전자들과 더불어 세포 내 ER stress도 영향을 받을 수 있음을 보여 주었다. 육계의 비타민 첨가 급여는 대조구에 비하여 지방대사 연관 유전자들의 발현이 비타민 첨가구에서 감소함에 따라 지방대사에도 영향을 미치고 있음을 보여주었다. 비타민의 첨가 유무와 관계없이 간세포 내부로 포도당을 운반하는 운반체인 GLUT 단백질들의 발현에는 큰 영향을 주지 못하였다. 본 연구의 결과는 육계에 사료 내 비타민 C 또는 E의 첨가급여가 닭의 스트레스 정도를 완화시킬 수 있으며, 또한 지방합성 대사에도 영향을 미칠 수 있음을 세포 수준의 관련 유전자들의 분석을 이용하여 검증할 수 있음을 보여 주었다.

• 한국식품영양학회지
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• 제22권3호
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• pp.456-462
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• 2009

Adlay, barley and rice bran were extracted using various concentrations of methanol(10% and 80%) and chloroform : methanol(2 : 1) to examine the biological activities of these raw grains. Extraction with 80% methanol resulted in high Vitamin C Equivalent Antioxidant Capacity(VCEAC), in the order of barley > rice bran > adlay, as determined by DPPH and ABTS assays. In addition, the extracts of adlay and rice bran showed high cellular antioxidant activity in HepG2 cells possibly due to the presence of polyphenol glycosides in these grains. We examined the expression of glucose/fatty acid metabolizing genes in differentiated 3T3-L1 adipocyte cells. Glut1 was downregulated after treatment with rice bran and no changes in the expression of Glut4 was observed. In contrast, genes involved in fatty acid metabolism, CD36 and aP2, were upregulated. Since these physiological changes were matched with peroxisome proliferator activating receptor $\gamma$(PPAR $\gamma$) agonism, we suggest that the extracts from adlay, barley and rice bran may play preventive roles against aging and diabetes via antioxidant activity and increased uptake of fatty acids by adipocytes.

• The Korean Journal of Physiology and Pharmacology
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• 제25권3호
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• pp.177-187
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• 2021

Metabolic syndrome (MBS) is a widespread disease that has strongly related to unhealthy diet and low physical activity, which initiate more serious conditions such as obesity, cardiovascular diseases and type 2 diabetes mellitus. This study aimed to examine the therapeutic effects of morin, as one of the flavonoids constituents, which widely exists in many herbs and fruits, against some metabolic and hepatic manifestations observed in MBS rats and the feasible related mechanisms. MBS was induced in rats by high fructose diet feeding for 12 weeks. Morin (30 mg/kg) was administered orally to both normal and MBS rats for 4 weeks. Liver tissues were used for determination of liver index, hepatic expression of glucose transporter 2 (GLUT2) as well as both inflammatory and fibrotic markers. The fat/muscle ratio, metabolic parameters, systolic blood pressure, and oxidative stress markers were also determined. Our data confirmed that the administration of morin in fructose diet rats significantly reduced the elevated systolic blood pressure. The altered levels of metabolic parameters such as blood glucose, serum insulin, serum lipid profile, and oxidative stress markers were also reversed approximately to the normal values. In addition, morin treatment decreased liver index, serum liver enzyme activities, and fat/muscle ratio. Furthermore, morin relatively up-regulated GLUT2 expression, however, down-regulated NF-κB, TNF-α, and TGF-β expressions in the hepatic tissues. Here, we revealed that morin has an exquisite effect against metabolic disorders in the experimental model through, at least in part, antioxidant, anti-inflammatory, and anti-fibrotic mechanisms.

• Journal of Ginseng Research
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• 제47권3호
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• pp.420-428
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• 2023

Background: Ginsenoside F2 (GF2), a minor component of Panax ginseng, has been reported to possess a wide variety of pharmacological activities. However, its effects on glucose metabolism have not yet been reported. Here, we investigated the underlying signaling pathways involved in its effects on hepatic glucose. Methods: HepG2 cells were used to establish insulin-resistant (IR) model and treated with GF2. Cell viability and glucose uptake-related genes were also examined by real-time PCR and immunoblots. Results: Cell viability assays showed that GF2 up to 50 μM did not affect normal and IR-HepG2 cell viability. GF2 reduced oxidative stress by inhibiting phosphorylation of the mitogen-activated protein kinases (MAPK) signaling components such as c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), and p38 MAPK, and reducing the nuclear translocation of NF-κB. Furthermore, GF2 activated PI3K/AKT signaling, upregulated the levels of glucose transporter 2 (GLUT-2) and GLUT-4 in IR-HepG2 cells, and promoted glucose absorption. At the same time, GF2 reduced phosphoenolpyruvate carboxykinase and glucose-6-phosphatase expression as well as inhibiting gluconeogenesis. Conclusion: Overall, GF2 improved glucose metabolism disorders by reducing cellular oxidative stress in IR-HepG2 cells via MAPK signaling, participating in the PI3K/AKT/GSK-3β signaling pathway, promoting glycogen synthesis, and inhibiting gluconeogenesis.

• 한국식품저장유통학회지
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• 제22권1호
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• pp.145-153
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• 2015

세리포리아 락세라타 균사체 배양물(CL01)의 혈당 강하 효과를 확인하기 위해 in-vitro 및 in-vivo 시험을 수행하였다. CL01이 INS-1 세포에서 덱사메타손에 의한 세포 사멸 방지 효과를 나타냈으며 3T3-L1 세포에서는 당수송체인 GLUT4의 발현을 증가시켰다. 제 2형 당뇨 마우스를 4 그룹(normal control (G1), negative control (G2), positive control (G3), CL01 250 mg/kg (G4))으로 나누어 6주간 매일 CL01을 투여한 후 혈중 지표를 확인한 결과, CL01 섭취군은 체중, 사료 및 물 섭취량에서 음성대조군 대비 유의적인 차이를 보이지 않았다. 투여 5주 후 CL01 섭취군의 혈당이 음성대조군 대비 유의적인 감소를 보였으며 6주 경과 시 혈중 인슐린은 36% 증가하였고 혈중 C-peptide 농도는 18% 감소하였다. 경구 당 부하 시험 결과 CL01 섭취군의 혈당이 음성대조군 대비 15% 감소하였다. 이상의 결과를 통해 CL01이 베타 세포를 증식시켜 인슐린 분비를 촉진하고 혈당을 낮추는 효과가 있음을 알 수 있다.

• Applied Biological Chemistry
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• 제47권2호
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• pp.258-264
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• 2004

한의학에서 당뇨병 (소갈) 처방으로 사용되는 옥천산 처방의 성분 중의 하나인 오미자의 포도당 이용에 대한 효과를 조사하기 위해서 오미자를 70% 에탄올로 추출한 후 메탄올과 물을 섞은 용액으로 단계별로 XAD-4 column 으로 분획하였다. 오미자를 복용한 후 혈당을 낮추기 위해서는 인슐린처럼 작용하는 인슐린성 물질이거나, 인슐린 작용을 향상시키는 인슐린 민감성 물질로 작용하거나, 또는 ${\alpha}-glucoamylase$ 활성을 억제하여 탄수화물의 소화를 방해 작용이 있어야 하므로 본 연구에서는 섬유아세포와 지방세포 3T3-L1에서 각 분획층이 이러한 3가지 기전에 관여하는 지를 조사하였다. 오미자 분획물은 인슐린성 물질로 작용하거나 ${\alpha}-glucoamylase$의 활성을 저하시켜 탄수화물의 소화를 방해하지 않았다. 그러나 오미자 분획층은 인슐린의 작용을 향상시켜 포도당의 흡수를 증가시키는 효과가 매우 컸다. 특히 오미자 분획층 중 Fr. 4(메탄올 60%)와 Fr. 5(메탄올 80%)는 지방세포 3T3-L1에서 포도당의 흡수를 현저하게 증가시켜 인슐린을 50 ng/ml를 처리한 것보다도 효과적으로 포도당 흡수를 증가시켰다. Fr. 4와 Fr. 5에서 포도당 흡수가 증가한 것은 Fr. 4와 5가 인슐린 작용을 향상시켜 세포막에 GLUT4양을 증가시진 결과이었다. 결론적으로 오미자 중 특히 Fr. 4와 Fr. 5에 인슐린 민감성 제제가 함유되어 있을 것으로 추정된다.

• Molecules and Cells
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• 제23권3호
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• pp.272-279
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• 2007

The maintenance of normal blood glucose levels at rest and during exercise is critical. The maintenance of blood glucose homeostasis depends on the coordination and integration of several physiological systems, including the sympathetic nervous system and the endocrine system. During prolonged exercise increased demand for glucose by contracting muscle causes to increase glucose uptake to working skeletal muscle. Increase in glucose uptake by working skeletal muscle during prolonged exercise is due to an increase in the translocation of insulin and contraction sensitive glucose transporter-4 (GLUT4) proteins to the plasma membrane. However, normal blood glucose level can be maintained by the augmentation of glucose production and release through the stimulation of liver glycogen breakdown, and the stimulation of the synthesis of glucose from other substances, and by the mobilization of other fuels that may serve as alternatives. Both feedback and feedforward mechanisms allow glycemia to be controlled during exercise. This review focuses on factors that control blood glucose homeostasis during prolonged exercise.

• 대한본초학회지
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• 제33권4호
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• pp.101-108
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• 2018

Objectives : This study aimed to effects antioxidant activity of citrus peel extract (CPE) and effect on its glucose metabolism in L6 rat skeletal muscle cells. Methods : Antioxidative activities were evaluated by using 10 kinds of natural materials, and total polyphenol and flavonoid contents were examined. The L6 muscle cells toxicity of CPE was examined by MTT assay. Expression of glucose-related genes in L6 muscle cells by CPE treatment was analyzed by real-time PCR and western blotting. Results : The $IC_{50}$ values of DPPH and ABTS free radical scavenging activity of CPE were ($15.47{\pm}0.26{\mu}g/m{\ell}$ and $12.07{\pm}1.23{\mu}g/m{\ell}$, respectively), effectively clearing DPPH and ABTS. CPE showed total polyphenol and flavonoid contents ($20.30{\pm}0.38$ and $64.20{\pm}0.52$, respectively). The selected CPE were used in experiments using an effective concentration that is not toxic in L6 muscle cells. We investigated insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase regulatory (PI3KR), Akt, and glucose transporter 4 (GLUT4). mRNA analysis by realtime PCR showed no significant difference, but CPE-treated cells showed a tendency to increase in concentration-dependent manner. However, analysis of protein expression of Akt and GLUT4 by western blotting showed that CPE treatment significantly increased concentration dependent (p<0.001). Conclusions : As a result, citrus peel extract with high antioxidant activity regulates glucose metabolism in L6 muscle cells. Therefore, CPE can be a potential treatment for the treatment of diabetes.

• The Korean Journal of Physiology and Pharmacology
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• 제20권2호
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• pp.153-160
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• 2016

The objective was to investigate the hypoglycemic action of catalpol in spontaneous diabetes db/db mice. 40 db/db mice were randomly divided into five groups: model control gourp; db/db plus catalpol 40, 80, 120 mg/kg body wt. groups and db/db plus metformin 250 mg/kg group. Age-matched db/m mice were selected as normal control group. The mice were administered with corresponding drugs or solvent by gavage for 4 weeks. The oral glucose tolerance test was carried out at the end of $3^{rd}$ week. After 4 weeks of treatment, the concentrations of fasting blood glucose (FBG), glycated serum protein (GSP), insulin (INS), triglyceride (TG), total cholesterol (TC) and adiponection (APN) in serum were detected. The protein expressions of phosphorylation-$AMPK{\alpha}$1/2 in liver, phosphorylation-$AMPK{\alpha}$1/2 and glucose transporter-4 (GLUT-4) in skeletal muscle and adipose tissues were detected by western blot. Real time RT-PCR was used to detect the mRNA expressions of acetyl-CoA carboxylase (ACC) and Hydroxymethyl glutaric acid acyl CoA reductase (HMGCR) in liver. Our results showed that catalpol could significantly improve the insulin resistance, decrease the serum concentrations of INS, GSP, TG, and TC. The concentrations of APN in serum, the protein expression of phosphorylation-$AMPK{\alpha}$1/2 in liver, phosphorylation-$AMPK{\alpha}$1/2 and GLUT-4 in peripheral tissue were increased. Catalpol could also down regulate the mRNA expressions of ACC and HMGCR in liver. In conclusion, catalpol ameliorates diabetes in db/db mice. It has benefit effects against lipid/glucose metabolism disorder and insulin resistance. The mechanism may be related to up-regulating the expression of phosphorylation-$AMPK{\alpha}$1/2.

• 한국식품영양과학회지
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• 제38권11호
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• pp.1528-1534
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• 2009

구기자는 식용가능하고 제2형 당뇨병 합병증인 지방간분해, 고혈압 및 고혈당에 효능이 있다고 알려져 있다. 하지만 당 대사 및 지질 대사에 작용하는 정확한 기작에 대한 연구는 아직 미비하기에 탄수화물 소화효소인 ${\alpha}$-amylase와 ${\alpha}$-glucosidase의 저해활성 및 정상생쥐를 이용한 혈당강하 효과와 3T3-L1 adipocyte를 통하여 비만축적 억제효과를 보았다. 구기자 추출은 80% MeOH, 70% EtOH 및 열수추출하였으며 이들 중 ${\alpha}$-amylase 50% 저해 활성($IC_{50}$)은 saliva ${\alpha}$-amylase에서 acarbose, 80% MeOH, 70% EtOH, aqueous(7.04, 3.19, 3.20, 3.66 mg/mL), pacreas ${\alpha}$-amylase acarbose, 80% MeOH, 70% EtOH, aqueous(10.97, 4.16, 3.07, 3.55 mg/mL)로 saliva ${\alpha}$-amylase에선 acarbose보다 80% MeOH, 70% EtOH 추출물이 가장 낮은 농도에서 $IC_{50}$값을 나타냈고 pacreas ${\alpha}$-amylase에서는 70% EtOH 추출물이 가장 낮은 농도에서 $IC_{50}$값을 나타냈다. 또한 10 ${\mu}g/mL$ 농도에서 yeast ${\alpha}$-glucosidase 활성저해 $IC_{50}$값은 80% MeOH, 70% EtOH, aqueous(5.01, 4.98, 4.80 ${\mu}g/mL$)로 구기자 추출물 모두 acarbose(5.05)보다 우수한 $IC_{50}$값을 나타냈다. 정상생쥐에게 탄수화물 소화효소의 저해활성이 높은 70% EtOH 추출물을 전분과 함께 경구투여 한 후 내당능을 측정한 결과, 전분과 함께 100, 200 mg/kg body weight를 경구투여 한 경우, 대조군에 비해 투여 후 30, 60, 90, 120분에 혈당 증가가 낮았다. 또한 추출물을 100 mg보다 200 mg 투여하였을 경우 대조군에 비해 각각 19% 및 40%씩 저하되었으며, 120분에는 대조군 수준이 되었다. 그리고 3T3-L1 adipocyte에서 비만축적 억제효과를 측정한 결과 70% EtOH 추출물 농도가 증가함에 따라 leptin, 중성지방 농도가 감소하였고 유리지방산 농도는 증가하였다. 이상의 연구 결과 구기자 추출물 중 70% EtOH는 acarbose보다 높은 ${\alpha}$-glucosidase, ${\alpha}$-amylase 저해활성을 나타냈으며, 정상생쥐를 통해 식후 혈당증가를 저하시키는 효과를 확인하였고 GLUT4 발현 역시 증가함을 확인했다. 이를 통해 구기자 추출물이 지방축적 억제와 인슐린 저항성 억제 및 혈당강하 기전을 확인하여 제2형 당뇨병 개선에 효과적인 것으로 판단, 추후 더 연구하여 보다 더 정확한 성분을 조사할 필요성이 있다고 사료된다.