• 한국식품영양학회지
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• 제23권2호
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• pp.233-239
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• 2010

Phenolic acid concentrates of rice bran(RB-ex) and hydroxycinnamic acids were investigated for their anti-hyperglycemic activities through glucose uptake and glucokinase activity using HepG2 cells and stimulatory effects on insulin secretion using HIT-T15 cells. RB-ex was prepared as an ethylacetate extract after alkaline hydrolysis and hydroxycinnamic acids, found as major compositions of RB-ex, such as ferulic acid(FA), sinapic acid(SA) and p-coumaric acid(p-CA) were investigated to compare with the properties of RB-ex. The properties of glucose uptake in HepG2 cells were examined in the absence of insulin and two different glucose concentrations(5.5 mM and 25 mM). RB-ex and FA showed anti-hyperglycemic activities through the increase of glucose uptake and the stimulation of glucokinase activity in HepG2 cells. RB-ex exhibited higher glucose uptakes with higher glucose concentrations, whereas FA exhibited the same increasing effects on both concentrations of glucose. RB-ex and FA exhibited doubled glucokinase activities relative to control. In the presence of insulin in the 25 mM glucose-containing medium, the levels of glucose uptake were increased in all treatments compared with control. As stimulatory effects of samples on insulin secretion were estimated, RB-ex and FA stimulated insulin secretion at a concentration of 25 ${\mu}g/m{\ell}$ and in particular, FA showed the highest amount of insulin-release in HIT-T15 cells. Antioxidative effects on HIT-T15 cells, RB-ex and hydroxycinnamic acids, excluding p-CA, showed inhibitory activities of 78% to 80% at a concentration of 100 ${\mu}g/m{\ell}$. On the basis of these results, we conclude that RB-ex and FA could help decrease blood glucose levels and prevent the cell damages via antioxidant activity.

• 생명과학회지
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• 제31권1호
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• pp.1-9
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• 2021

본 연구는 갈조류 유래 물질인 후코이단이 인슐린 민감성을 증진시키는지를 규명하기 위하여 3T3-L1 지방세포에서 포도당 흡수에 미치는 후코이단의 영향을 측정하고 그 작용기전을 조사하였다. 후코이단은 지방세포에서 포도당 흡수를 유의하게 증가시켰으며 이는 PM-GLUT4의 발현 증가와 관련이 있음을 관찰하였다. 후코이단은 인슐린 신호전달 경로에서 PI3K의 활성화 및 pIRS1tyr, Akt, PKCλ/ζ의 인산화를 대조군에 비해 유의하게 증가시켰다. 또한, AMPK의 활성화를 나타내는 pAMPK 수준이 유의하게 증가하였다. 이들 PI3K 및 AMPK 활성화는 포도당 수송체인 GLUT4를 세포막으로 이동시켰으며 이로 인하여 PM-GLUT4의 발현이 증가되고 포도당 흡수가 촉진되었다. 후코이단에 의한 PI3K 및 AMPK 경로의 활성화를 증명하기 위해, PI3K 억제제인 Wortmannin과 AMPK의 억제제인 Compound C를 사용하여 이들 처리에 의한 포도당 흡수능과 PM-GLUT4의 발현을 측정한 결과 이들의 발현이 유의하게 저해되었다. 따라서 후코이단은 3T3-L1 지방세포에서 PI3K 및 AMPK 경로를 활성화시킴으로써 인슐린 민감성을 증진하고 포도당 흡수를 촉진시킬 수 있음을 나타내었다.

• 상하수도학회지
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• 제8권2호
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• pp.25-34
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• 1994

In this research, investigations were made on the effect of type and load of organic substrate on phosphorus release. Reactors of three different sizes were operated, being fed on five kinds of organic substrates. The quantitative analyses were made on phosphorus release and substrate utilization under anaerobic condition. The molar ratios of the uptaken organic substrate to the released phosphorus were 0.5 with acetate, 0.6 with glucose, 0.8 with glucose/acetate, and 1.2 with glucose/acids, respectively. The phosphorus release was inhibited at the higher organic load than the normal at stead state. Both acetate and acids/glucose enhanced phosphorus release- as well as uptake-rate, however, the complete phosphorus removal was achieved after the microbial adaptation to the new environment. In case with acetate, operation was hampered by the poor sludge settleability and phosphorus uptake was not enough although the phosphorus release was active. But with milk/starch, the phosphorus release and uptake was well developed even though phosphorus release was not comparatively high. From this study, it was concluded that organic substrates, such as glucose seemed to be converted fatty acids after fast bio-sorption, followed by concurrent uptake of these acids by excess phosphorus removing bacteria.

• 한국미생물·생명공학회지
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• 제16권5호
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• pp.402-406
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• 1988

발효생산된 에탄올의 농도가 Zymomonas mobilis 에서 당대사에 관련된 효소의 역가에 미치는 영향을 조사하였다. 그 결과, glucose kinase 및 glucose 6-phosphate dehydrogenase는 큰 영향을 받지 않았으나 transketolase 역가는 에탄을 농도가 증가함에 따라 심하게 저해됨을 알았다. 따라서 에탄을 농도의 증가에 따른 균성장속도의 감소는 transketolase에 의하여 영향을 받는 것으로 생각되었다.

• Journal of Yeungnam Medical Science
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• 제9권1호
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• pp.121-129
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• 1992

STZ투여 전후 2주씩 4주간의 규칙적인 운동 부하가 당뇨흰쥐의 골격근 당섭취와 당내성에 미치는 영향을 알아보기 위하여 Sprague-Dawley종 수컷 흰쥐를 사용하여 soleus근의 당섭취를 시험관에서 $^3H$-3-O-methyl-glucose의 섭취로 추적하였으며 정맥으로 당을 부하 (0.5g/kg BW)하여 당내성을 평가한 본 실험의 결과를 요약하면 다음과 같다. STZ의 투여로 대조군에 비하여 공복시 혈당과 유리지방산이 증가하고 인슐린 농도, soleus근의 당섭취, 인슐린에 대한 예민도와 반응도, 및 근 glycogen농도는 감소하였으며 내당능이 저하하였다. STZ 투여 흰쥐에서 4주간의 규칙적인 운동으로 인한 변화로 안정군에 비하여 공복시 혈당이 감소하고 soleus근의 당섭취와 인슐린에 대한 반응도 및 근glycogen 의 농도가 증가하였으며 유리지방산의 농도가 감소하는 경향을 보였다. 그러나 인슐린 농도는 차이가 없었으며 당내성은 개선되지 않았다. 위의 결과로 보아 4주간의 운동은 STZ 투여후 당뇨 흰쥐 발생율에는 영향을 미치지 못하였으나 골격근의 인슐린 반응도는 향상시켰으며 공복시 혈당도 감소시키는 효과를 나타내었다. 그러나 저하된 내당능은 골격근의 인슐린 반응도가 향상되었음에도 불구하고 개선되지않은 것으로 사료된다.

• 한국식품영양학회지
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• 제11권5호
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• pp.550-555
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• 1998

The purpose of this study was to investigate the effects of n-3 polyunsaturated fatty acids(PUFA) on glucose and lipids metabolism in high-fat diet rate. Rats were randomly assigned to normal, high-fat with n-3 PUFA and high-fat dietary groups. Experiments were carried out after 5 weeks feeding with prescriptive diets following 7 hrs fasting. Body weight gains tended to be higher in high-fat fed rats than normal. Blood glucose was increased (p<0.05) by high-fat diet compared with normal diet, and decreaseed (p<0.05) to normal level by n-3 PUFA. Plasma insulin level was significcantly higher (p<0.01) in high-fat diet rats than that of normal-diet rats, and also decreased (p<0.01) by n-3 PUFA. Glucose up take of soleus muscle in vitro was decreased markedly in high-fat fed rats than normal diet rats at 0, 1, 10, and 100nM insulin concentration. Therefore insulin sensitivity and responsiveness were decreased by high-fat diet. Omega-3 PUFA made a recover(p<0.01) insulin sensitivity to almost normal level, and improved (p<0.05) insulin responsiveness in some extent. In conclusion, the results suggest that metabolic disorder of glucose and insulin resistance of skeletal muscle are caused by high-fat diet and n-3 PUFA can ameliorate metabolic disorder and insulin resistance.

• Molecules and Cells
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• 제41권6호
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• pp.562-574
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• 2018

The tazarotene-induced gene 1 (TIG1) protein is a retinoidinducible growth regulator and is considered a tumor suppressor. Here, we show that DnaJ heat shock protein family member C8 (DNAJC8) is a TIG1 target that regulates glycolysis. Ectopic DNAJC8 expression induced the translocation of pyruvate kinase M2 (PKM2) into the nucleus, subsequently inducing glucose transporter 1 (GLUT1) expression to promote glucose uptake. Silencing either DNAJC8 or PKM2 alleviated the upregulation of GLUT1 expression and glucose uptake induced by ectopic DNAJC8 expression. TIG1 interacted with DNAJC8 in the cytosol, and this interaction completely blocked DNAJC8-mediated PKM2 translocation and inhibited glucose uptake. Furthermore, increased glycose uptake was observed in cells in which TIG1 was silenced. In conclusion, TIG1 acts as a pivotal repressor of DNAJC8 to enhance glucose uptake by partially regulating PKM2 translocation.

• Nutrition Research and Practice
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• 제10권1호
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• pp.11-18
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• 2016

BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. $\small{D}$-xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of $\small{D}$-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS: Wistar rats were divided into the following groups: (i) normal control; (ii) diabetic control; (iii) diabetic rats supplemented with a diet where 5% of the total sucrose content in the diet was replaced with $\small{D}$-xylose; and (iv) diabetic rats supplemented with a diet where 10% of the total sucrose content in the diet was replaced with $\small{D}$-xylose. These groups were maintained for two weeks. The effects of $\small{D}$-xylose on blood glucose levels were examined using oral glucose tolerance test, insulin secretion assays, histology of liver and pancreas tissues, and analysis of phosphoenolpyruvate carboxylase (PEPCK) expression in liver tissues of a STZ-NA-induced experimental rat model. Levels of glucose uptake and insulin secretion by differentiated C2C12 muscle cells and INS-1 pancreatic ${\beta}$-cells were analyzed. RESULTS: In vivo, $\small{D}$-xylose supplementation significantly reduced fasting serum glucose levels (P < 0.05), it slightly reduced the area under the glucose curve, and increased insulin levels compared to the diabetic controls. $\small{D}$-xylose supplementation enhanced the regeneration of pancreas tissue and improved the arrangement of hepatocytes compared to the diabetic controls. Lower levels of PEPCK were detected in the liver tissues of $\small{D}$-xylose-supplemented rats (P < 0.05). In vitro, both 2-NBDG uptake by C2C12 cells and insulin secretion by INS-1 cells were increased with $\small{D}$-xylose supplementation in a dose-dependent manner compared to treatment with glucose alone. CONCLUSIONS: In this study, $\small{D}$-xylose exerted anti-diabetic effects in vivo by regulating blood glucose levels via regeneration of damaged pancreas and liver tissues and regulation of PEPCK, a key rate-limiting enzyme in the process of gluconeogenesis. In vitro, $\small{D}$-xylose induced the uptake of glucose by muscle cells and the secretion of insulin cells by ${\beta}$-cells. These mechanistic insights will facilitate the development of highly effective strategy for T2D.

• 대한약침학회지
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• 제20권1호
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• pp.45-51
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• 2017

Objectives: This study aimed to evaluate the hypoglycemic effects of an ethanol extract of Cassia abbreviata (ECA) bark and the possible mechanisms of its action in diabetic albino rats. Methods: ECA was prepared by soaking the powdered plant material in 70% ethanol. It was filtered and made solvent-free by evaporation on a rotary evaporator. Type 2 diabetes was induced in albino rats by injecting 35 mg/kg body weight (bw) of streptozotocin after having fed the rats a high-fat diet for 2 weeks. Diabetic rats were divided into ECA-150, ECA-300 and Metformin (MET)-180 groups, where the numbers are the doses in mg.kg.bw administered to the groups. Normal (NC) and diabetic (DC) controls were given distilled water. The animals had their fasting blood glucose levels and body weights determined every 7 days for 21 days. Oral glucose tolerance tests (OGTTs) were carried out in all animals at the beginning and the end of the experiment. Liver and kidney samples were harvested for glucose 6 phosphatase (G6Pase) and hexokinase activity analyses. Small intestines and diaphragms from normal rats were used for ${\alpha}-glucosidase$ and glucose uptake studies against the extract. Results: Two doses, 150 and 300 mg/kg bw, significantly reduced the fasting blood glucose levels in diabetic rats and helped them maintain normal body weights. The glucose level in DC rats significantly increased while their body weights decreased. The 150 mg/kg bw dose significantly increased hexokinase and decreased G6Pase activities in the liver and the kidneys. ECA inhibited ${\alpha}-glucosidase$ activity and promoted glucose uptake in the rats' hemi-diaphragms. Conclusion: This study revealed that ECA normalized blood glucose levels and body weights in type 2 diabetic rats. The normalization of the glucose levels may possibly be due to inhibition of ${\alpha}-glucosidase$, decreased G6Pase activity, increased hexokinase activity and improved glucose uptake by muscle tissues.

• 한국식품영양과학회지
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• 제42권8호
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• pp.1197-1203
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• 2013

본 연구는 2주간의 지구성 운동과 ginsenoside $Rb_1$이 쥐골격근의 AMPK insulin signaling($tAMPK{\alpha}$, $pAMPK{\alpha}$ $Thr^{172}$)과 PI3K insulin signaling pathway(pIRS-1 $Tyr^{612}$, PI3K $p^{85}$, pAkt $Ser^{473}$) 발현 및 glucose uptake에 미치는 영향을 분석하였다. 골격근내 glucose uptake에서는 비교집단과 비교하여 운동집단(59.4%), $Rb_1$집단(70.5%) $Rb_1/Ex$집단(58.6%)에서 유의하게 증가하였다. 2주간의 지구성 운동과 ginsenoside $Rb_1$이 AMPK insulin signaling pathway에 미치는 효과를 조사한 결과 비교집단에 비해 $AMPK{\alpha}$(Ex, 28.6%; $Rb_1$, 28.5%; $Rb_1/Ex$, 29.8%), $pAMPK{\alpha}$ $Thr^{172}$(Ex, 35.1%; $Rb_1$, 35.3%; $Rb_1/Ex$, 30.9%)의 발현이 유의하게 증가한 것을 알 수 있었다. 2주간의 지구성 운동과 ginsenoside $Rb_1$이 PI3K insulin signaling pathway에 미치는 효과를 알아본 결과 비교집단과 비교하여 IRS-1, PI3K $p^{85}$에서는 유의한 차이가 없었으나 pAkt $Ser^{473}$은 $Rb_1$ 집단에서 유의하게 증가한 것을 알 수 있었다. 이상의 결과를 종합해 볼 때, ginsenoside $Rb_1$은 운동과 더불어 근육 세포내 AMPK의 활성화와 근육 내 glucose uptake를 증가시켜 제2형 당뇨병 예방과 치료에 효과가 있을 것으로 생각된다. 그러나 본 연구의 결과로 PI3K insulin signaling pathway의 항당뇨 효과는 설명하기는 부족하다고 판단되며 추후 본 연구의 결과를 기초로 ginsenoside $Rb_1$의 농도, 처치시간, 처치방법을 고려한 후속 연구가 필요할 것으로 생각된다.