• BMB Reports
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• v.32 no.2
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• pp.161-167
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• 1999

The role of oxidative stress in the initiation and the complication of diabetes was examined by monitoring blood glucose increase and oxidative DNA damage in rats treated with alloxan or streptozotocin (STZ). Oxidative DNA damage was assessed by quantitating 8-oxo-2'-deoxyguanosine ($oxo^8dG)$ excreted in urine and the $oxo^8dG$ accumulated in pancreas DNA. Both alloxan and STZ treatments resulted in an abrupt increase in blood glucose and significant increases in urinary and pancreatic $oxo^8dG$. Pretreatment of buthionine sulfoximine (BSO), a glutathione-depleting agent, slightly potentiated the increase of blood glucose and urinary $oxo^8dG$ in the alloxan- and STZ-treated rats. Furthermore, the BSO pretreatment caused significant amplification of pancreatic $oxo^8dG$ increase in the rats. On the other hand, pretreatment with 1,10- phenanthroline (o-phen), a chelator of divalent cations, showed different results between alloxan- and STZ-treated rats. The o-phen pretreatment completely blocked diabetes and the increase of $oxo^8dG$ by alloxan treatment, while it potentiated the increase of blood glucose and $oxo^8dG$ by STZ treatment. The results demonstrate that the causative effect of alloxan on diabetes may be the generation of reactive oxygen species through a Fenton type reaction, but that of STZ may not.

• Natural Product Sciences
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• v.22 no.3
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• pp.175-179
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• 2016

The aim of this study was to evaluate the anti-diabetic effects of the water extract of Lespedeza cuneata (LCW) using rat insulinoma (RIN) m5F cells and streptozotocin (STZ)-induced diabetic rats. The effect of LCW on the protection of pancreatic beta cells was assessed using MTT assay, and nitric oxide production was assessed using Griess reagent. STZ-induced diabetic rats were treated with 100 and 400 mg/kg body weight of LCW for 5 weeks. In results, LCW significantly protected cytokine-induced toxicity and NO production, and increased insulin secretion in RINm5F cells. LCW significantly decreased serum blood glucose, thiobarbituric acid reactive substances (TBARS), blood urea nitrogen (BUN) and advanced glycation end products (AGEs) levels, and renal fibronectin expression in STZ-induced diabetic rats. Also, LCW effectively improved BW loss in STZ-induced diabetic rats. Thus, our results suggest that LCW has a beneficial effect on cytokine-induced pancreatic beta cell damage and biomarkers of diabetic complication in hyperglycemic rats.

• Korean Journal of Pharmacognosy
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• v.40 no.3
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• pp.213-217
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• 2009

This study was done to investigate the antioxidative effect of polygoni radix 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 ethanol extract of Polygoni radix was orally administrated once a day for 7 days. The contents of Total cholesterol, triglyceride (TG) were significantly decreased in Polygoni radix treated STZ-sample group compared with to the those of STZ-control group. The hepatic cytosolic activities of glutathione-s-transferase (GST), superoxide dismutase (SOD) were significantly increased, Also the content of glutathione (GSH) was incresaed in Polygoni radix treated STZ-sample group compared with to the those of STZ-control group. but the content of malondialdehyde (MDA) and the hepatic cytosolic activity of Catalase (CAT) were decreaed but not statistical significant. These results indicated that ethanol extract of polygoni radix was effective for the antidxidative in the STZ-induced diabetic rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.908-913
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• 1997

The purpose of this study was to investigate phospholipase $A_{2}$ activity and lipid peroxidation I streptozotocin induced diabetic rats. Sprague-Dawley male rats weighting-Dawley male rats weighting 300$\pm$10gm were randomly assigned to normal and STZ-induced diabetic group. Diabetes was induced by intravenous injection of 55mg/kg of STZ in sodium citrate buffer(pH 4.3). Animals were sacrificed at the 6th day of diabetic states. Body weight gains were lower in DM group. Phosphatidylcholine hydrolysis in liver was not significantly different between two groups, whereas phosphatidylethanolamine hydrolysis in liver was increased by 69% in DM group comparing with that of normal group. Liver microsomal phospholipase $A_{2}$ activity and level of TBARS was increased by 91%, 109% in DM group compared with that of normal group, respectively. The present results indicate that phospholipase $A_{2}$ activity is specific to PE hydrolysis, leading to lipid peroxidation process in STZ induced diabetic rats.

• 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.

• 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 Nutrition and Health
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• v.30 no.7
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• pp.743-750
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• 1997

The hypoglycemic effects of 2 mushrooms, Pleurotus ostreatus and Lentinus edodes, on streptozotocin(STZ) induced diabetic rats were investigated in this study . Diabets mellitus was induced in male Sprague-Dawley rats by the injection of STZinto the tail vein at a dose of 45mg/kg. Sprague-Dawley male rats(200-250g) were assigned to one control and three STZ-diabetic groups. Diabetic groups were assigned to STZ-control, pleurotus ostreatus and Lenitinus edodes groups. All groups were fed a AIN 76 diet. The two experimental groups were fed with each protein-bound polysaccharide(150mg/kg BW) for 14 days and with carboxymethyl cellulose for STZ-control group. The body weight gain was monitored and the blood levels of glucose and cholesterol were measured . Levels of protein triglyceride, and free fatty acid in plasma were analysed. Serum aminotransferase activity as also measured. The body weight gain was lower in the all diabetic groups than in the of normal group. The weight of spleen was reduced by adminstration of the Lentinus edodes protein-bound polysaccharides. The result suggest that orally administered Lentinus edodes protein-bound polysaccharides exhibited hypoglycemic effect in STZ -induced diabetic rats and that these protein-bound polysaccharides may be useful for the management of diabetes mellitus.

• Culinary science and hospitality research
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• v.13 no.3
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• pp.199-206
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• 2007

Hypoglycemic efficacy of natural functional mixture(FM) and level of the diabete related hormones in streptozotocin(STZ)-induced diabetic rats were investigated. Male Sprague-Dawley rats were divided into three groups (normal, diabetic fed diets with/without FM). Supplement of FM did not affect the body weight and feed intake of STZ-induced diabetic rats. The increase in the weight of liver of STZ-induced diabetic rats was weakened by supplement of FM, whereas the weight of kidney and heart was not affected. Blood glucose level was slightly, and glucose tolerance of post-feeding was significantly improved by functional mixture. The mixture significantly reduced the elevated HbA1C level of diabetic rats by 15%, and it increased the level of insulin and C-peptide in blood and decreased glucagon level. Therefore, we conclude that FM in this study has a potency of prevention and treatment of diabetes mellitus.

• Reproductive and Developmental Biology
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• v.34 no.4
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• pp.299-304
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• 2010

To identify the treatment effect of lactic acid bacteria for diabetes, the treatment effects of a single administration of acarbose (a diabetes treatment drug) or lactic acid bacteria, and the mixture of acarbose and lactic acid bacteria on diabetes in a type 1 diabetes animal model, were studied. In this study, streptozotocin was inoculated into a Sprague-Dawley rat to induce diabetes, and sham control (Sham), diabetic control (STZ), STZ and composition with live cell, STZ and composition with heat killed cell, STZ and composition with drugs (acarbose) were orally administered. Then the treatment effect on diabetes was observed by measuring the body weight, blood glucose, and serum lipid. For the histopathological examination of the pancreas, the Langerhans islet of the pancreas was observed using hematoxylin and eosin staining, and the renal cortex, outer medullar, and inner medullar were also observed. The induced diabetes decreased the body weight, and the fasting blood glucose level decreased in the lactic-acid-bacteria-administered group and the mixture-administered group. In addition, the probiotic resulted in the greatest decrease in the serum cholesterol level, which is closely related to diabetes. Also, the hematoxylin and eosin staining of the Langerhans islet showed that the reduction in the size of the Langerhans islet slowed in the lactic-acid-bacteria-administered group. The histopathological examination confirmed that the symptoms of diabetic nephropathy decreased in the group to which viable bacteria and acarbose were administered, unlike in the group to which dead bacteria was administered. The mixture of lactic acid bacteria and acarbose and the single administration of lactic acid bacteria or acarbose had treatment effects on the size of the Langerhans islet and of the kidney histopathology. Thus, it is believed that lactic acid bacteria have treatment effects on diabetes and can be used as supplements for the treatment of diabetes.

• The Korea Journal of Herbology
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• v.23 no.3
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• pp.85-91
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• 2008

Objectives : This study aimed to evaluate the anti-diabetic effect of Wen-Pi-Tang-Hab-Wu-Ling-San (WHW) extract in streptozotocin(STZ)-induced type-1 diabetic rats. Methods : Experimental diabetes were induced by intraperitoneal injection of streptozotocin (60 mg/kg). Two groups of STZ-induced diabetic rats were given the following treatments for 2 weeks by oral Administrations : (1) WHW 10 mg/kg, (2) WHW 100 mg/kg. In addition, vehicle-treated diabetic and nondiabetic controls were used in the experiment. The effects of WHW extract on STZ-induced diabetes were observed by measuring the changes of body weights and the levels of fasting blood glucose, insulin, urea nitrogen (BUN) and creatinine level in sera of rats, respectively. Results : In comparison control group, WHW-treated groups (100 mg/kg) were significantly decreased fasting blood glucose levels and increased serum insulin levels in STZ-induced diabetic rats. Moreover, WHW-treated groups (100 mg/kg) were reduced s-creatinie levels in STZ-induced diabetic rats. In addition, the changes related to diabetic nephropathy with body weight were significantly lower in WHW extract-dosing groups than in the diabetic control. Conclusions : The study thus showed that WHW extract enhanced the anti-diabetic effect in STZ-induced diabetic rats by improving the hypoglycemia. It also increased pancreatic insulin content in these rats.