• 대한의생명과학회지
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• 제17권4호
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• pp.283-289
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• 2011

Our previous study demonstrated that the Korean traditional medicine Gyeongshingangjeehwan (GGEx) activates AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) 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 $PPAR{\alpha}$ 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 $PPAR{\alpha}$. GGEx also increased skeletal muscle mRNA levels of AMPK${\alpha}1$, AMPK${\alpha}2$, and $PPAR{\alpha}$. 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 $PPAR{\alpha}$ activation.

• The Korean Journal of Physiology and Pharmacology
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• 제12권1호
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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.

• 한국식품영양과학회지
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• 제30권3호
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• pp.521-527
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• 2001

The effects of dietary restriction (DR) on antioxidant enzymes were studied in liver, lung and erythrocytes of diabetic rats. Experimental animals used Sprague-Dawley (SD; body weight 350$\pm$20g) male rats and Otsuka Long Evans Tokushima fatty (OLETE; body weight 5--$\pm$30g) male rats, as a model of type 2 diabetes mellitus. Type I diabetes was induced in SD rats by intramuscular injection of alloxan (80 mg/kg BW). Animals were randomly assigned either to continue the ad libitum diet or 40% DR (60% intake of ad libitum diet) groups. The body weight was measured at every 2 weeks to 4 months following DR. The activities of antioxidant enzymes (superoxide dismutase (SOD), catalase, glutathione peroxidase (GSHPx) were measured in liver, lung and erythrocytes and the concentration of TBARS as a marker of reactive oxygen species-induced tissue injry was also measured in rats after 4 months 40% DR. The body weight 4 months after 40% DR of control SD, alloxian-diabetid SD and OLETE rats were 80%, 98% and 75% of each control groups, respectively. The activities of SOD, catalase and GSHPx in lung and erythrocytes of rats were not change by 40% DR but in 4 month 40% DR rat liver, the activities of SOD and catalase were increased in control SD, alloxan-diabetic SD, and OLETF groups. The concentration of TBARS in lung and erythrocytes was also not changed by 40% DR, while liver TBARS concentration was decreased in OLETF and control SD rats compared to each non-DR control rats. These results suggested that the body weight changes in diabetic rats by DR was more prominent in type 2 diabetes and changes of antioxidant enzymes is most prominent in liver by DR either type 1 and 2 diabetic rats.

• The Korean Journal of Physiology and Pharmacology
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• 제19권4호
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• pp.309-318
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• 2015

Alcohol consumption increases the risk of type 2 diabetes. However, its effects on prediabetes or early diabetes have not been studied. We investigated endoplasmic reticulum (ER) stress in the pancreas and liver resulting from chronic alcohol consumption in the prediabetes and early stages of diabetes. We separated Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a type-2 diabetic animal model, into two groups based on diabetic stage: prediabetes and early diabetes were defined as occurrence between the ages of 11 to 16 weeks and 17 to 22 weeks, respectively. The experimental group received an ethanol-containing liquid diet for 6 weeks. An intraperitoneal glucose tolerance test was conducted after 16 and 22 weeks for the prediabetic and early diabetes groups, respectively. There were no significant differences in body weight between the control and ethanol groups. Fasting and 120-min glucose levels were lower and higher, respectively, in the ethanol group than in the control group. In prediabetes rats, alcohol induced significant expression of ER stress markers in the pancreas; however, alcohol did not affect the liver. In early diabetes rats, alcohol significantly increased most ER stress-marker levels in both the pancreas and liver. These results indicate that chronic alcohol consumption increased the risk of diabetes in prediabetic and early diabetic OLETF rats; the pancreas was more susceptible to damage than was the liver in the early diabetic stages, and the adaptive and proapoptotic pathway of ER stress may play key roles in the development and progression of diabetes affected by chronic alcohol ingestion.

• 한국식품과학회지
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• 제46권1호
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• pp.100-107
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• 2014

본 연구에서는 염생식물인 칠면초와 세발나물의 인슐린 저항성을 개선하는 효과를 조사하였다. 본 실험에 사용한 OLETF쥐는 CCK-1 수용체의 결함으로 인해 인슐린 저항성을 걸쳐 제 2형 당뇨병이 유발되는데, 인슐린 저항성이 진행되는 10주령부터 28주령이 될 때까지 칠면초와 세발나물을 18주 동안 섭취시켰다. 염생식물식이군들의 체중이나 공복혈당 변화는 식이기간 동안 전반적으로 대조군과 유의적인 차이를 보이지 않았다. Oral glucose tolerance test에서 염생식물 섭취가 당 내성을 개선하는 효과를 보였으나 그 혈당 변화를 면적으로 환산하였을 때 각 식이군들 간의 유의적인 차이는 관찰되지 않았다. 혈중 insulin 및 HbA1c 수치는 유의하게 낮은 수치를 보였으며, adiponectin 수치는 높고 leptin과 ghrelin 수치는 낮았으나 현저한 차이는 관찰되지 않았다. 세발나물식이군의 혈중 중성지질과 총 cholesterol 수치는 대조군에 비해 유의적으로 더 낮았다. 혈중 지질산화물 함량은 각 식이군 간 유의차가 관찰되지 않았으나 염생식물식이군에서 더 낮은 경향을 보였으며, NF-${\kappa}B$ p65는 지방조직에서 유의적으로 낮은 발현량을 보였다. 또한 두 염생식물식이군에서 인슐린 신호전달의 negative regulator인 $pIRS1^{Ser307}$의 발현량은 대조군에 비해 더 낮음을 확인하였다. 그러므로 칠면초와 세발나물은 생후 성장하면서 인슐린 저항성이 생기는 OLETF쥐의 인슐린 저항성을 현저하게 줄여주지는 못하였으나 그 개선 효과는 있는 것으로 시사되며, 두 염생식물의 급여 기간을 늘려 제 2형 당뇨병을 예방하는 효과에 대한 섬세한 검토가 보완되어야 할 것으로 사료된다.

• Archives of Plastic Surgery
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• 제39권2호
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• pp.106-112
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• 2012

Background : Complicated diabetic patients show impaired, delayed wound healing caused by multiple factors. A study on wound healing showed that platelet-rich plasma (PRP) was effective in normal tissue regeneration. Nonetheless, there is no evidence that when platelet-rich plasma is applied to diabetic wounds, it normalizes the diabetic wound healing process. In this study, we have analyzed matrix metalloproteinase (MMP)-2, MMP-9 expression to investigate the effect of PRP on diabetic wounds. Methods : Twenty-four-week-old male Otsuka Long-Evans Tokushima Fatty rats were provided by the Tokushima Research Institute. At 50 weeks, wounds were arranged in two sites on the lateral paraspinal areas. Each wound was treated with PRP gel and physiologic saline gauze. To determine the expression of MMP-2, MMP-9, which was chosen as a marker of wound healing, reverse transcription polymerase chain reaction (RT-PCR) was performed and local distribution and expression of MMP-2, MMP-9 was also observed throughout the immunohistochemical staining. Results : RT-PCR and the immunohistochemical study showed that the levels of MMP-2, MMP-9 mRNA expression in PRP applied tissues were higher than MMP-2, MMP-9 mRNA expression in saline-applied tissues. MMP-9 mRNA expression in wounds of diabetic rats decreased after healing began to occur. But no statistical differences were detected on the basis of body weight or fasting blood glucose levels. Conclusions : This study could indicate the extracellular matrix-regulating effect observed with PRP. Our results of the acceleration of wound healing events by PRP under hyperglycemic conditions might be a useful clue for future clinical treatment for diabetic wounds.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2012년도 심포지엄 및 춘계학술발표회
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• pp.315-316
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• 2012

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.449-454
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• 2009

5'-AMP-activated protein kinase (AMPK) is a heterotrimeric complex consisting of a catalytic ($\alpha$) and two regulatory ($\beta$ and $\gamma$) subunits. Two isoforms are known for catalytic subunit (${\alpha}1$, ${\alpha}2$) and are encoded by different genes. To assess the metabolic effects of $AMPK{\alpha}1$, we examined the effects of overexpression of adenoviral-mediated $AMPK{\alpha}1$ in hyperlipidemic type 2 diabetic rats. The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an established animal model of type 2 diabetes that exhibits chronic and slowly progressive hyperglycemia and hyperlipidemia. Thirty five-week-old overt type 2 diabetic rats (n=10) were administered intravenously with Ad.$AMPK{\alpha}1$. AMPK activity was measured by phosphorylation of acetyl CoA carboxlyase (ACC). To investigate the changes of gene expression related glucose and lipid metabolism, quantitative real-time PCR was performed with liver tissues. Overexpression of $AMPK{\alpha}1$ showed that blood glucose concentration was decreased but that glucose tolerance was not completely recovered on 7th day after treatment. Plasma triglyceride concentration was decreased slightly, and hepatic triglyceride content was markedly reduced by decreasing expression of hepatic lipogenic genes. Overexpression of $AMPK{\alpha}1$ markedly improved hepatic steatosis and it may have effective role for improving hepatic lipid metabolism in hyperlipidemic state.

• Journal of Chest Surgery
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• 제40권4호
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• pp.264-272
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• 2007

배경: 혈관내피 성장인자(vascular endothelial growth factor, VEGF)는 혈관평활근세포(vascular smooth muscle cell)의 증식과 이동을 촉진함으로써 혈관신생에 중요한 역할을 한다. 당뇨병은 VEGF의 발현과 연관되어 정상 혈당상태에서 보다 세포의 증식을 더욱 촉진시킨다. 당뇨병쥐에서 VEGF 수용체의 선택적 차단이 손상된 혈관에서 신내막 형성과 혈관평활근세포의 이동에 미치는 영향에 대해 알아보고자 했다. 대상 뜻 방법: 당뇨병 쥐의 경동맥 풍선손상 모델에서 위약을 투여하거나, 혈관내피 성장 인자 수용체-1(VEGFR-1)에 선택적으로 작용하는 항-Flt-1 펩타이드(anti-Flt-1 peptide; Gly-Asn-Gln-Trp-Phe-Ile)를 풍선손상 2일 전부터 0.5mg/kg의 용량으로 2주간 매일 투여한 군으로 나누어 Hematoxylin-Eosin 염색을 하여 신내막의 형성정도와 혈관내강의 협착정도를 비교하였으며, proliferative cell nuclear antigen (PCNA)에 대한 면역조직화학염색법을 시행하여 세포의 증식정도를 관찰하였다. 혈관평활근세포를 고혈당환경에서 배양하고 transwell assay를 시행하여 혈관평활근세포의 이동 정도를 측정하였다. 고혈당 환경에서 자라고 있는 혈관평활근세포에 50ng/mL의 VEGF를 단독 또는 3ug/mL의 항-Flt-1 펩타이드와 함께 처리하고 일정시간이 지난 후 matrigel filter를 통과한 세포를 세어 아무런 처치를 받지 않은 세포가 이동한 정도와 비교하였다. 또한, 혈관평활근세포에 세포이동 정도 측정 시와 같은 처리를 한 후, RNA를 분리하고 reverse transcription-polymerase chain reaction (RT-PCR)을 시행하여 기질금속단백분해효소(matrix metalloprotenase, MMP)의 발현 정도를 관찰하였다. 결과: 신내막의 면적은 위약 투여 쥐는 $0.24{\pm}0.03 mm^2$이었으나, 항-Flt-1 펩타이드의 처리에 의해 $0.15{\pm}0.04 mm^2$로 유의하게 감소하였으며(p<0.01), 신내막 형성에 따른 내강의 협착 정도도 위약 투여 쥐는 $61.85{\pm}5.11%$, 항-Flt-1 펩타이드 투여 쥐는 $36.03{\pm}3.78%$로 항-Flt-1 펩타이드 투여에 의하여 유의하게 감소하였다(p<0.01). 신내막의 전체 세포수에 대한 PCNA(+)인 세포를 백분율로 구하였으며, 위약 투여 쥐와 항- Flt-1 펩타이드 투여 쥐에서 각각 $52.82{\pm}4.20%,\;38.11{\pm}6.89%$로 나타나 항-Flt-1 펩타이드를 투여한 쥐에서 PCNA(+)인 세포가 유의하게 적음을 보이고 있다(p<0.05). 혈관평활근세포의 이동 정도 측정에서는 항-Flt-1 펩타이드 처리에 의하여 VEGF에 의한 혈관평활근 세포의 이동이 유의하게 감소하였다(p<0.01). 또한, 항-Flt-1 펩타이드 처리에 의하여 VEGF에 의한 MMP-3와 MMP-9 mRNA의 발현 증가가 억제되었다. 결론: 항-Flt-1 펩타이드는 당뇨병쥐의 경동맥손상모델에서 신내막 형성을 억제하였으며, 고혈당 환경에서 배양된 혈관평활근세포의 이동과, MMP-3와 MMP-9의 활성을 억제하였다.

• 한국약용작물학회지
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• 제25권3호
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• pp.165-174
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• 2017

Background: Traditional plant drugs, are less toxic and free from side effects compared to general synthetic drugs. They have been used for the treatment of diabetes and associated renal damage. In this study, we evaluated effect of Hachimi-jio-gan against diabetic renal damage in a rat model of type 1 diabetic nephropathy induced by subtotal nephrectomy plus streptozotocin (STZ) injection, and in Otsuka Long-Evans Tokushima Fatty (OLETF) rats and db/db mice as a model of human type 2 diabetes, and its associated complications. To explore the active components of Hachimi-jio-gan, the antidiabetic effect of corni fructus, a consituent of Hachimi-jio-gan, and 7-O-galloyl-${{\small}D}$-sedoheptulose, a phenolic compound isolated from corni fructus, were investigated. Methods and Results: We conducted an extensive literature search, and all required data were collected and systematically organized. The findings were reviewed and categorized based on relevance to the topic. A summary of all the therapeutic effects were reported as figures and tables. Conclusions: Hachimi-jio-gan serves as a potential therapeutic agent to against the development of type 1 and type 2 diabetic nephropathy. From the results of characterization active components of corni fructus, 7-O-galloyl-${\small}D$-sedoheptulose is considered to play an important role in preventing and/or delaying the onset of diabetic renal damage. 7-O-Galloyl-${\small}D$-sedoheptulose is expected to serve as a novel therapeutic agent against the development of diabetic nephropathy.