• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.475-482
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• 2015

This study was conducted to examine whether or not oligonol, a low molecular weight polyphenol derived from lychee fruit, has an ameliorative effect on diabetes-induced oxidative stress-related hepatic damage in streptozotocin (STZ)-induced diabetic rats. Oligonol (10 or 20 mg/kg body weight; O10 or O20, respectively) was orally administered every day for 10 days to STZ-induced diabetic rats, and its effects were compared to vehicle-treated diabetic (Veh) and non-diabetic rats. Administration of 20 mg/kg of oligonol significantly decreased liver weight compared with the Veh group (P<0.05). Elevated levels of hepatic glucose, reactive oxygen species, peroxynitrite, and lipid peroxidation were detected in diabetic vehicle rats, whereas oligonol treatment significantly attenuated these levels (P<0.05). In diabetic vehicle rats, hepatic antioxidant enzyme protein levels decreased, whereas oligonol treatment showed significant elevated results. For inflammation-related protein expression, oligonol-treated groups showed insignificant reduction. Oligonol improved expression of proapoptotic protein caspase-3 in the liver of diabetic rats (P<0.05). In conclusion, these results provide important evidence that oligonol exhibits an inhibitory effect on oxidative stress and apoptosis-related protein expression as well as a hepato-protective effect against the development of diabetic complications in STZ-induced type 1 diabetic rats.

• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.5
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• pp.264-269
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• 2017

Prunella vulgaris, well-known traditional medicinal plant, is used for the cure of abscess, scrofula, hypertension and urinary diseases. Diabetic nephropathy is the most common cause of end-stage renal disease. The pathological characteristics of diabetic nephropathy are glomerular and tubular basement membrane thickening. The aim of the present study was to evaluate the effect of Prunella vulgaris, on diabetic glomerular injury in streptozotocin-induced diabetes rats. Diabetes mellitus was induced by a single intraperitoneal injection of streptozotocin (STZ; 45 mg/kg) and confirmed by random glucose level higher than ${\leq}300mg/dL$. The experimental rats were divided into five groups: control group (Male SD rats), STZ group (Male SD rats injected STZ), Aminoguanidine group (Male SD rats injected STZ + AG 100 mg/kg/day), Low dose group (Male SD rats injected STZ + APV 100 mg/kg/day), High dose group (Male SD rats injected STZ + APV 300 mg/kg/day). AG or APVs were administered once a day for 8 weeks. Body weight and food/water intake were measured every four weeks. At the end of study, the kidneys were collected and cut into pieces for immunohistochemistry and western blot analysis. Our study showed that body weight and water/food intake were no significant differences between untreated STZ-induced diabetic rat and APV treated-STZ rat. However, phosphorylation of receptor-regulated Smads (Smad3) was significantly decreased in APV treated-STZ rat as compared with the diabetic group. In addition, APV was improved nephrin level in kidney tissue. Therefore, we suggest that APV has a protective effect against STZ-induced diabetic glomerular injury.

• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.300-308
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• 2004

This study was done to investigate the antidiabetic effect of Glechoma hederacea LINNAEUS in Streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose of 45 mg/kg dissolved in citrate buffer. The methanol extract of Glechoma hederacea was orally administrated once a day for 6 days. The contents of serum glucose, triglyceride (TG), total cholesterol and Atherogenic Index (Al) were significantly decreased, but high density lipoprotein (HDL)-cholesterol and HDL-cholesterol/total cholesterol ratio (HTR) were significantly increased in Glechoma hederacea treated STZ-sample group compared to the those of STZ-control group. The content of hepatic lipid peroxide and activity of catalase were decreased, but content of glutathione as well as activities of glutathione-S-transferase and superoxide dismutase were increased in Glechoma hederacea treated STZ-sample group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucose-6-phosphate dehydrogenase, glucokinase were significantly increased, but activity of glucose-6-phosphatase was decreased in Glechoma hederacea treated STZ-sample group compared to the those of STZ-control group. These results indicated that methanol extract of Glechoma hederacea would have antidiabetic effect in STZ-induced diabetic rats.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.489-496
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• 2000

This study was conducted to investigate the effects of streptozotocin-induced (STZ) diabetes on insulin-like growth factor-I (IGF-I), insulin-like growth factor binding proteins (IGFBPs), and IGF-I carrier proteins in serum, liver, and kidney. The levels of total and free IGF-I were measured by radioimmunoassay (RIA). The patterns of IGFBPs were determined by western ligand blotting (WLB) analysis. The profiles of IGF-I carrier proteins in serum were determined by column chromatography. The levels of total and free IGF-I in serum were lower in STZ-induced diabetic rat than normal rat (p<0.01). Similarly, the levels of total IGF-I in liver was lowered in STZ-induced diabetic rats. On the other hand, the levels of total IGF-I in kidney were increased in STZ-induced diabetic rats compared with normal rats (p<0.01). In serum and liver from STZ-induced diabetic rats, the amount of IGFBP-3 was decreased and the amount of IGFBP-2 was increased compared with normal rats. There was a not difference in amount of IGFBP-4 in serum between STZ-induced diabetic rats and normal rats. The serums of normal rats have higher 150kDa carrier proteins than in STZ-induced diabetic rats, whereas, most of 50kDa carrier proteins were found in STZ-induced diabetic rats. These results demonstrate that in STZ-induced diabetic rats, IGF-I/IGFBPs system that included functional bioactivity was changed in serum as well as tissues, and these changes may play an important role in pathogenesis of diabetes.

• Korean Journal of Pharmacognosy
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• v.47 no.4
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• pp.312-318
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• 2016

Advanced glycation end products (AGEs) such as $N^{\varepsilon}$-(carboxy-methyl)lysine (CML) have been implicated in the development of diabetic nephropathy. The aim of this study was to investigate the inhibitory effects of ethanolic extract of Aster koraiensis (AKE) on AGEs formation and AGEs-collagen cross-linking in vitro and CMLs formation in streptozotocin (STZ)-induced diabetic rats. AKE significantly inhibited AGEs formation ($IC_{50}$ value of $18.74{\mu}g/mL$) and AGEs-collagen cross-linking ($IC_{50}$ value of 0.274 mg/mL) in vitro than the well-known glycation inhibitor aminoguanidine ($IC_{50}$ value of $72.12{\mu}g/mL$ and 1.99 mg/mL, respectively). AKE (100 mg/kg per day) was given to diabetic rats for 9 weeks. In STZ-induced diabetic rats, severe hyperglycemia was developed, and urinary CMLs and plasma CMLs were markedly increased. Immunohistochemical stain revealed that CMLs were accumulated within renal glomerulus in STZ-induced diabetic rats. However, AKE significantly reduced urinary CMLs and plasma CMLs in diabetic rats. CMLs accumulation was inhibited by AKE treatment in the renal glomerulus. These results suggest that AKE had an inhibitory effect of AGE accumulation in the glomeruli of diabetic rat and could be an inhibitor of AGE-induced protein cross-linking. The oral administration of AKE may significantly help to prevent the progression of diabetic nephropathy in patients with diabetes.

• Advances in Traditional Medicine
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• v.8 no.2
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• pp.146-153
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• 2008

The present study is aimed at finding the influence of silymarin (a flavonoid) (25 mg/kg & 50 mg/kg) in streptozotocin (STZ)-induced diabetic rats. Type 2 diabetes was induced by single intraperitoneal injection of STZ (100 mg/kg) to 3 days old rat pups. Silymarin was administered for 15 days after the animals were confirmed diabetic (75 days after STZ injection). Blood glucose, glycosylated hemoglobin ($HbA_{1c}$), lipid peroxides (LPO) levels and reduced glutathione (GSH) contents in pancreas and liver were estimated following the established procedures. Biochemical observations were further substantiated with histological examination of pancreas. Blood glucose and $HbA_{1c}$ levels, which were elevated by STZ, were lowered to physiological levels by the administration of silymarin. The levels of LPO were significantly increased in STZ-induced diabetic rats. Silymarin reduced the LPO levels in both pancreas and liver. GSH contents which were reduced significantly in pancreas and liver of STZ-induced diabetic rats were brought back to near normal levels by silymarin treatment. Multifocal necrotic and degenerative changes of pancreas in STZ-diabetic rats were minimized to near normal morphology by administration of silymarin as evident by histopathological examination. Silymarin showed a dose dependent protective effect on STZ-induced $\beta$-cell damage. It could be attributed to the antioxidative and free radicals scavenging properties of the flavonoid. Thus, it may be considered as a natural antioxidant with potential therapeutic application in the treatment of type 2 diabetes.

• Journal of Life Science
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• v.21 no.3
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• pp.435-443
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• 2011

The purpose of this study is to identify the effects of exercise training [ET, 10~18 m/min (speed), 20~30 min (exercise duration)/a day for 5 day/wk, 6 wk) on PGC-$1{\alpha}$, GLUT-1, Tfam, Cu,Zn-SOD and Mn-SOD proteins in brain of STZ-induced diabetic rats. The male Sprague-Dawley (SD) rats were single-injected intraperitoneally with 50mg/kg of streptozotocin (STZ) to produce STZ-induced diabetic rats. Rats were divided into 3 experimental groups with 8 rats in each group, as follows: (1) non-STZ group (n=8), (2) STZ-CON group (n=8), (3) STZ-EXE group (n=8). The results of this study suggest that i) serum glucose level was significantly reduced in STZ-EXE group compared with STZ-CON group (p<0.05), ii) PGC-$1{\alpha}$ (p<0.001), mtPGC-$1{\alpha}$ (p<0.001), GLUT-1 (p<0.001), and mtTfam (p<0.001) proteins in brain of STZ-induced diabetic rats were significantly increased in STZ-EXE group compared with STZ-CON group, iii) Cu,Zn-SOD (p<0.001) and Mn-SOD (p<0.01) proteins in the STZ-induced diabetic rats were significantly increased in STZ-EXE group compared with STZ-CON group. In conclusion, the findings of the present study reveal that treadmill exercise training increases brain GLUT-1 protein level possibly through up-regulation of PGC-$1{\alpha}$ and Tfam proteins which represent key regulatory components of stimulation of brain mitochondrial biogenesis. In addition, treadmill exercise training may prevent oxidative stress by up-regulation of Cu,Zn-SOD and Mn-SOD proteins in the STZ-induced diabetic rats.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.452-465
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• 1998

Rosae laevigatae Fructus extract (RLF) was tested for the effects on the urethral nitric oxide synthase (NOS) activity and Antioxidation in streptozotocin (STZ) induced diabetic rats. RLF was treated firstly into samples, and then STZ induced diabetic rats were set with them. In vitro, the urethral NOS activity was not noted but the type O activity and type conversion ratio of xanthine oxidase and the level of urethral lipid peroxide were decreased in the level of Dose of extract prepared from RLF. In vivo, after the extract was administered to the animal model for fifteen days, the urethral NOS activity increased in STZ induced diabetic rats to the level of normal rats. The content of urethral nitrite and glutathione followed by RLF pre-medicating administration, increased as highly as normal group in compare with the group treated with STZ. The type O activity and type conversion ratio of xanthine oxidase and the level of urethral lipid peroxide followed by RLF pre-medicating administration, decreased as lowly as normal group in compare with the group treated with STZ. In conclusion, the extract of RLF will be able to restore erectile dysfunction of STZ induced diabetic rats.

• The Journal of Internal Korean Medicine
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• v.28 no.3
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• pp.510-518
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• 2007

Objectives : The aim of this study was to investigate the effect of Jaeumyangyung-tang(滋陰養榮場(JY), JA-0.65g/kg;JB-1.3g/kg) on hyperglycemic mice induced with streptozotocin(STZ). Methods : The experiment operated for 6 weeks. The rats were divided into 3 groups : diabetic group(control group), diabetic group treated with JA(0.65g/kg) for 6 weeks, and diabetic group treated with Jb(1.3g/kg) for 6 weeks. Results : In the STZ-induced diabetic group, blood glucose levels significantly increased as well as the loss of body weight. The levels of serum glucose decreased significantly (p<0.05 or p<0.01) in the JA and JB groups compared with the control. According to a tolerance test, intraperitoneal glucose was ameliorated in the JA and JB groups. The blood urea nitrogen (BUN) and creatinine levels slightly decreased. Histologic analyses of the pancreases revealed that the ${\beta}-cells$ on Langerhans' islets were destroyed by STZ, but the ${\beta}-cell$ mass was larger in the JY than in the control mice. Conclusions : These results indicate that JY can exert beneficial effects on diabetes. preservation of in vivo ${\beta}-cell$ function and regeneration of ${\beta}-cell$ dysfunction by STZ.

• Journal of Acupuncture Research
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• v.26 no.6
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• pp.1-9
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• 2009

Objectives : For evaluation of preventive and anti-diabetic activities of Cinnamomi ramulus(CR) herbal acupuncture on pancreatic islet damage in streptozotocin(STZ)-induced diabetic rat. Methods : CR herbal acupuncture was performed at Bisu($BL_{20}$) for 3 weeks subcutaneously starting1 week before STZ i.p. injection. SD rats were divided into four groups(n=10 for each group); 1) NC group, non-treated normal control group, 2) STZ group, STZ administered control group, 3) CR125 group, CR(125mg/kg) + STZ administered group, and 4) CR250 group, CR(250mg/kg) + STZ administered group. Results : Both of CR250 and CR125 groups showed increase in insulin secretion and decrease in the level of serum triglyceride and non-esterified fatty acid in a dose-dependent manner compared to the STZ group. Only CR250 group showed decrease in the levels of glucose and total cholesterol compared to the STZ group. CR herbal acupuncture prevents $\beta$-cell damage of pancreatic islet, showing round figure on the sections of the pancreas. In the pancreatic cells, expressions of iNOS, JNK-2, P-JNK-1/2 and ERK-1/2 were decreased compared to the STZ group. CR herbal acupuncture solution did not show any cytotoxicity by MTS assay and inhibited expressions of iNOS and COX-2 in the STZ-induced diabetic rats. Conclusions : Therefore, we suggest that CR herbal acupuncture may act as a prophylactic as well as a therapeutic modality for diabetes mellitus.