• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.48-56
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• 2009

This study was conducted to examine the effects of Opuntia ficus-indica complexes(OCB) on the intake of water and food, body weight, blood glucose levels, glucose tolerance and lipid metabolism in streptozotocin(STZ)-induced diabetic rats. Thirty-two male Sprague-Dawley rats were assigned to four different groups; non-diabetic control(NC), diabetic control (DC), diabetic OCB of 2%(OCB-2), and diabetic OCB of 5%(OCB-5). The animals were fed on each experimental diet for 3 weeks. The DC, OCB-2 and OCB-5 groups showed a higher intake of water and food than the NC group. The fasting blood glucose levels were 100 $ mg/d{\ell}$ and 416 $ mg/d{\ell}$ for the NC and DC groups, respectively. The OCB-5 group presented a significantly low fasting glucose level of 21%(P<0.05), while OCB-2 group had a decrease of 13% compared to the DC group. As for the results of the glucose tolerance test, the highest blood glucose level was observed for all the groups at 30 minutes after the glucose injections as well as higher plasma insulin levels in the OCB-5 group. Plasma total cholesterol, triglyceride, non-esterified fatty acids(NEFA) and LDL-cholesterol concentrations were also lower in the OCB-2 and OCB-5 groups. The experimental diet did not affect the HDL-cholesterol levels. The overall results suggest that the higher intake of food by the OCB-2 and OCB-5 groups improved the blood glucose levels and lipid metabolism in STZ-induced diabetic rats.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.91-101
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• 2020

The purpose of this study was to investigate the influence of obesity on the expression of autophagy-related proteins in cardiac muscle. To this end, obesity was induced in rats through 20 weeks of high-fat diet, and the animals were then subjected to 8 weeks of treadmill exercise. Subsequently, the expression of proteins that regulate the induction of autophagy, formation of autophagosome, and fusion of autophagosome and lysosome was confirmed. Obesity was induced in the experimental animals (SD rats) through 20 weeks of high-fat diet (carbohydrate: 20%, fat: 60%, and protein: 20%), and they were subsequently subjected to 8 weeks of treadmill exercise (5 days/week, 30 min/day, 5 minutes; 8m/min, 5 minutes; 11m/min, 20 minutes; 14m/min). The experimental groups comprised the normal diet control group (ND-CON, n=10), high-fat diet comparison group (HFD-CON, n=10), and high-fat exercise group (HFD-TE, n=10). Oral glucose tolerance test was conducted before and after 8 weeks of treadmill exercise, and the area under the curve (AUC) was calculated. Through fasting insulin and fasting glucose levels, HOMA-IR, which is an index of insulin resistance, and abdominal visceral fat/body weight (AVF/BW) were calculated for comparison. Moreover, autophagy-related proteins were analyzed from cardiac tissue to investigate the effects of exercise training. Obesity was successfully induced in the HFD-CON group through long-term high-fat diet, and the HFD-CON group had higher body weight, AUC, HOMA-IR, and AVF/BW compared to the ND-CON group. The HFD-TE group, which underwent 8 weeks of treadmill exercise, showed improvements in AUC, HOMA-IR, and AVF/BW. Although the body weight tended to decrease as well, there was no statistically significant difference. mTOR and AMPK, which are involved in the induction of autophagy, both decreased in obesity but increased upon exercise. Beclin-1, BNIP3, ATG-7, p62, and LC3, which are related to the formation of autophagosomes, all increased in obesity and decreased after exercise. Cathepsin L and LAMP2, which regulate the fusion of autophagosome and lysosome, both decreased in obesity and increased upon exercise. Physical activity, including treadmill exercise, was found to induce normal autophagy and improve pathological phenomena observed in metabolic diseases. Therefore, the findings suggest the need to consider treadmill exercise as a primary means to achieve effective prevention and treatment of cardiac diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.701-707
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• 2008

Antidiabetic effect of Korean red ginseng (RG) processed by puffing in streptozotocin (STZ)-induced diabetic (DM) rats was investigated. Five week-old SD rats were divided into four groups; normal control (NC) group, DM group, red ginseng (RG) group and puffed red ginseng (PG) group. The RG and PG groups were orally provided with RG or PG dissolved in water (500 mg/kg) respectively for seven weeks after single injection of STZ (50 mg/kg, i.v.) followed by identification of DM. NC group received saline vehicle instead of STZ. At the end of feeding of RG or PG, the changes of fasting blood glucose, serum insulin and amylase level and serum lipid profiles were evaluated. Also, oral glucose tolerance test (OGTT), comet assay and histopathological examination were performed. At 7th week, the fasting blood glucose levels of the RG and PG groups were reduced compared to the DM group by 11.54% and 20.22%, respectively. The result of OGTT did not show significant differences among DM and two red ginseng groups. While serum insulin and TG levels were predominantly improved in PG group (p<0.05), serum amylase level was increased in RG group. Alkaline comet assay for checking the oxidative damage of DNA showed that TL (tail length, ${\mu}m$) and TM (tail moment) in the blood lymphocyte of PG group significantly decreased in contrast with DM group. Histopathological results of pancreas showed that destruction of exocrine as well as endocrine might be cured by the administration of RG and PG. These results suggest that PG could exert more protection against STZ-induced toxicity than RG group.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1319-1326
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• 2007

Fructose-1,6-bisphosphatase (FBP1) is a key regulatory enzyme of gluconeogenesis that catalyzes the hydrolysis of fructose-1,6-bisphosphate to generate fructose-6-phosphate and inorganic phosphate. Deficiency of fructose-1, 6-bisphosphatase is associated with fasting hypoglycemia and metabolic acidosis. The enzyme has been shown to occur in bacteria, fungi, plants and animals. The bovine FBP1 gene was cloned and characterized in this study. The full length (1,241 bp) FBP1 mRNA contained an open reading frame (ORF) encoding a protein of 338 amino acids, a 63 bp 5' untranslated region (UTR) and a 131 bp 3' UTR. The bovine FBP1 gene was 89%, 85%, 82%, 82% and 74% identical to the orthologs of pig, human, mouse, rat and zebra fish at mRNA level, and 97%, 96%, 94%, 93% and 91% identical at the protein level, respectively. This gene was broadly expressed in cattle with the highest level in testis, and the lowest level in heart. An intronic single nucleotide polymorphism (SNP) (A/G) was identified in the $5^{th}$ intron of the bovine FBP1 gene. Genotyping of 133 animals from four beef breeds revealed that the average frequency for allele A (A-base) was 0.7897 (0.7069-0.9107), while 0.2103 (0.0893-0.2931) for allele B (G-base). Our preliminary association study indicated that this SNP is significantly associated with traits of Average Daily Feed Intake (ADFI) and Carcass Length (CL) (p<0.01). In addition, the FBP1 gene was assigned on BTA8 by a hybrid radiation (RH) mapping method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1126-1132
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• 2004

The present study was undertaken to evaluate the effect of functional food, which was processed with fermented soybean as main ingredient (FS), on the body weight, organ weight, plasma glucose, and plasma lipid in diabetic rats caused by streptozotocin (STZ). The body weight was decreased more slowly in the FS group than in the diabetic, and the food intake increased significantly in all diabetic groups. The food efficiency was very low in all diabetic groups, but increased significantly in the FS groups than diabetic control (p＜0.05). In comparing the weight of organ, the weight of liver and kidney were increased in all diabetic groups than in the control, and decreased slightly in FS groups. The weight of heart and spleen were not different among all test groups. In the oral glucose tolerance test, the blood glucose in the diabetic group was the highest in 60 minutes. And the blood glucose in the FS group was the highest in 30 minutes, and decreased significantly after 120 minutes to the level of fasting glucose. The glucose in serum was decreased significantly in the FS groups fed the functional food for 4 weeks, compared to the diabetic control (p＜0.05). Total cholesterol, triglyceride and atherogenic index (AI) in serum were significantly higher in diabetic control, compared to the normal (p＜0.05), and decreased by 16.4％, 15.4％ and 48.3％, respectively, in the FS fed 400 mg/kg of functional food. HDL-cholesterol was increased significantly in the FS-400, compared to the diabetic control. These results support that functional food using fermented soybean improve glucose and lipid metabolism in diabetic rats.

• Food Science and Preservation
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• v.20 no.1
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• pp.1-6
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• 2013

In this study, the effect of Curcuma longa L. on obesity and insulin resistance was investigated in animals fed a moderate high fat diet. The animals used in this study were normal weight Spargue-Dawley (SD) rats and type 2 diabetic obese db/db mice. Accumulation of abdominal adipose tissue and weight gain were inhibited in the animals fed the C. longa extract. C. longa decreased fasting insulin and HOMA-IR in the SD rats, and effectively decreased blood glucose and hemoglobin A1c in db/db mice. C. longa decreased serum free fatty acid (FFA) level in the SD rats. FFA in db/db mice fed C. longa tended to decrease. C. longa significantly decreased serum triglyceride level. Our results collectively represent that C. longa prevented fat accumulation and insulin resistance in both normal weight SD rats and type 2 diabetic obese db/db mice fed a moderate high fat diet.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.4
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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.

• Nutrition Research and Practice
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• v.10 no.1
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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.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.99-105
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• 2012

Objectives : Korean red ginseng and Morus alba L. are used as a traditional treatment for diabetes. This study was designed to elucidate whether combination with Korean red ginseng and Morus alba L. (MPM) ameliorates metabolic syndrome in fructose-fed rats. Methods : Animals were divided into four groups; Control receiving tap water, fructose-fed, rosiglitazone-treated fructose-fed rats, and MPM-treated fructose-fed rats both receiving supplemented with 60% fructose (n=10). The MPM or rosiglitazone groups initially received a high-fructose (HF) diet alone for 8 weeks, with supplementation with MPM or rosiglitazone occurring during the final 6 weeks. Results : MPM and rosiglitazone, synthetic $PPAR{\gamma}$ agonist, treatment significantly prevented the increase in fasting serum glucose, leptin, triglyceride, and low density lipoprotein in the HF group when comparing with the control group. MPM and rosiglitazone also led to an increase in high density lipoprotein level in the HF group. The administration of MPM and rosiglitazone prevented the development of the metabolic disturbances such as impaired glucose tolerance, and blood pressure. MPM suppressed increased expressions of endothelin-1 (ET-1) in HF rat aorta. In addition, MPM significantly increased IR-${\beta}$ and PPAR-${\gamma}$ expression in muscle. Conclusions : Based on these results, we suggest that the administration of MPM improves metabolic syndrome through the alteration in lipid profiles and suppression of insulin resistant and blood pressure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1727-1733
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• 2012

This study was conducted to investigate the effects of Vaccinium uliginosum L. (bilberry) on chemically induced diabetes and hypercholesterolemia. Sprague Dawley (SD) rats were divided into six groups, control (CON), bilberry added group (CBB), streptozotocin (STZ)-induced diabetic group (STZ), STZ and bilberry added group (SBB), high fat fed group (HFF) and high fat and bilberry added group (HFB). Diabetes was chemically induced by intravenous injection of 45 mg/kg body weight STZ in citrate buffer (pH 4.5). Serum triglycerides decreased significantly (p<0.05) in the STZ group that was fed bilberry. Additionally, the athrogenic index (AI) decreased significantly (p<0.05) when compared to the STZ group, while the liver triglycerides tended to decrease in the STZ group. HDL-cholesterol also increased significantly in response to bilberry. When compared to the STZ group, steady attenuation of the blood glucose level was observed upon fasting, 15 min, 30 min, 60 min and 120 min after oral glucose administration. The blood glucose level in the bilberry fed group decreased by 24% when compared to STZ group, while the superoxide dismutase (SOD) became significantly higher (p<0.05) in the STZ group when compared to the CON group. Overall, the results of this study suggest that bilberry stimulates lipid metabolism in both the serum and liver and has a positive effect on glucose metabolism in chemically induced diabetic rats.