• Imaging Science in Dentistry
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• v.35 no.3
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• pp.147-156
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• 2005

Purpose : To observe the histopathological changes and caspase-3 expression in the submandibular gland in streptozotocin-induced diabetic rats after irradiation. Materials and Methods : The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups: control, diabetes, irradiation, and diabetes-irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only. After 5days, rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10 Gy to the head and neck region. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the submandibular gland were sectioned and observed using histopathological and immunohistochemical methods. Results : In the irradiation group, the condensed nucleus, karyolysis, and degeneration of the acinar cells and atrophy of the duct cells were observed in the early experimental phase. However, the acinar cells were found to be normal at 28 days after irradiation. In the diabetes group, the condensed nucleus, karyolysis, atrophy, and degeneration of the acinar cells were observed in the early experimental phase. However, the acinar cells were found to be normal at 21 days after diabetic state induction. In the diabetes-irradiation group, the ductal epithelial cells were predominant in their glandular tissues at 28 days after irradiation. In all of the experimental groups, the most prominent change of the acinar cells and ductal cells were observed at 14 days after diabetic state induction and irradiation. Conclusion The expression of caspase-3 in the acinar cells and ductal cells of the submandibular gland was weak after irradiation, but that in the acinar cells, ductal cells, and fibrous cells of the submandibular gland was prominent after diabetic state induction.

• Biomolecules & Therapeutics
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• v.26 no.2
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• pp.130-138
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• 2018

Quercetin and resveratrol are known to have beneficial effects on the diabetes and diabetic complication, however, the effects of combined treatment of these compounds on diabetes are not fully revealed. Therefore, the present study was designed to investigate the combined antidiabetic action of quercetin (QE) and resveratrol (RS) in streptozotocin (STZ)-induced diabetic rats. To test the effects of co-treated with these compounds on diabetes, serum glucose, insulin, lipid profiles, oxidative stress biomarkers, and ions were determined. Additionally, the activities of hepatic glucose metabolic enzymes and histological analyses of pancreatic tissues were evaluated. 50 male Sprague-Dawley rats were divided into five groups; normal control, 50 mg/kg STZ-induced diabetic, and three (30 mg/kg QE, 10 mg/kg RS, and combined) compound-treated diabetic groups. The elevated serum blood glucose levels, insulin levels, and dyslipidemia in diabetic rats were significantly improved by QE, RS, and combined treatments. Oxidative stress and tissue injury biomarkers were dramatically inhibited by these compounds. They also shown to improve the hematological parameters which were shown to the hyperlactatemia and ketoacidosis as main causes of diabetic complications. The compounds treatment maintained the activities of hepatic glucose metabolic enzymes and structure of pancreatic ${\beta}-cells$ from the diabetes, and it is noteworthy that cotreatment with QE and RS showed the most preventive effect on the diabetic rats. Therefore, our study suggests that cotreatment with QE and RS has beneficial effects against diabetes. We further suggest that cotreatment with QE and RS has the potential for use as an alternative therapeutic strategy for diabetes.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.287-294
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• 2008

Protective effects of cheonggukjang fermented with 20% red ginseng (RC) were observed in streptozotocin (STZ)-induced diabetic rats by measuring levels of blood glucose, serum lipid profiles, and hepatic reactive oxygen species generating and scavenging enzymc activities. RC diet was prepared by mixing with AIN-76 diet at the final concentration 2%, and it was fed to STZ-induced diabetic rats for 3 weeks. The RC dict was significantly improved body weight, feed efficiency ratio, levels of serum glucose, and serum and hepatic lipids in diabetes. The significantly elevated O type activity of xanthine oxidase in diabetes was also greatly decreased by the RC diet. The treatment of RC showed the improved hepatic glutathione s-transferase activities in the diabetic animals. The present study indicates that cheonggukjang fermented with red ginseng could ameliorate STZ-induccd diabetic symptoms such as aggravated blood glucose levels, serum lipid profiles, and even the conditions of oxidative stress.

• Journal of Food Hygiene and Safety
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• v.16 no.4
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• pp.349-354
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• 2001

Oxidative stress is believed to play an important role in the development of vascular complications associated with diabetes mellitus. We examined the antioxidative effect of sesamin and sesamolin on the preventing the development of insulin dependent diabetes mellitus using streptozotocin-induced Spraque Dawley diabetic rats. From 48 hours after injection of streptozotocin (60 mg/kg body weight), a portion of diabetic rats were fed with 0.2% sesamin and sesamolin containing diet for 3 weeks. There were significant differences of blood glucose and kidney weight between diabetic ports and control. Sesamin and sesamolin increased glutathione-S-transferase activity in kidney. The concentration of the thiobarbituric acid-reactive substances in the serum, liver, and kidney of diabetic rats administered sesamin and sesamolin decreased significantly as compared with that of the non-treated diabetic group. Dietary sesamin and sesamolin suppressed the oxidative stress in the diabetic rats. These results demonstrated that sesamin and sesamolin are potential and effective antioxidants that can protect the complications associated with diabetes.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.175-175
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• 1993

Streptozotocin, which is a naturally occurring nitrosoamide used extensively to produce diabetes mellitus in experimental animals, has been known to be chemically stable only under acidic condition (pH 4). The present study was conducted to determine whether its degradation products formed under various conditions can induce hyperglycemia in female rats. Streptozotocin in phosphate buffer saline (pH 7.4) resulted in spontaneous degradation rapidly. Furthermore, streptozotocin incubated with plasma isolated from rats was degraded even faster than those in neutral buffer. When streptozotocin was administered iv to rats, significant elevations in blood glucose level were observed within 24 hours. However, rats treated with equimolar concentration of streptozotocin degradation products under the phosphate buffer saline as well as the plasma did not lead to hyperglycemia. These results suggest that, when streptozotocin administered undergo spontaneous breakdown in vivo, its degradation Products do not induce the hyperglycemia in rats.

• Journal of Life Science
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• v.19 no.3
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• pp.334-342
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• 2009

This study investigates the effects of Psidium guajava L. leaf (Pg), Lagerstroemia speciosa L. leaf (Ls) and mixture A (Pg, Ls, Morus indica L. leaf extract, Pinus densiflora needles extract, Acanthopanax senticosus M. root extract) on streptozotocin (STZ)-diabetes rats. For four weeks, STZ-diabetes rats were fed crystallized extracts of Pg, Ls, and mixture A. Compared to the diabetic control group, extracts of Pg, Ls, and mixture A decreased glucose levels in rats by 20%, 14% and 24% respectively. These extracts also decreased the level of total cholesterol, triglyceride and free fatty acid, compared to the diabetic control group, while effectively increasing levels of insulin and high-density lipoprotein-cholesterol. These results showed that mixture A had greater antihyperglycemic, antihyperlipidemic, and insulin-increasing effects than the Pg and Ls extracts. Mixture A also showed better restoration of damaged beta cell function compared to Pg and Ls extracts. Therefore, it was proved that mixture A provides a beneficial synergistic effect when compared with Pg and Ls extracts used individually.

• Herbal Formula Science
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• v.14 no.2
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• pp.57-66
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• 2006

Objectives : The objective of this study is to observe the effect of Saryuktangkamibang, Saryuktang with Liriopis Tuber, Lycii Fructus, Schizandrae Fructus, and Bombyx Batryticatus, on the experimental diabetes. Methods : In order to induce diabetes experimentally, injected streptozotocin to the vein in the tail of rats and then treated oral administration of Saryuktangkamibang water extracts. In the measurement of the variation levels of glucose, ALP, creatinine, and BUN concentration for each concentration levels for serum (0.2g/100g, 0.4g/l00g, 0.6g/100g), concentration level of glucose significantly decreased in 0.4g/l00g concentration level of Saryuktangkamibang. With this 0.4g/l00g concentration level of Saryuktangkamibang, the following conclusion was derived from the measurement of the serum levels of glucose. ALP, AST, ALT, creatinine, and BUN concentration for the injection of each 4th, 11th, and 18th day. Results : 1. In the measurement for each concentrations, the glucose concentration level in the serum significantly decreased on the 9th day in the Saryuktangkamibang-dosed group. 2. The creatinine and BUN concentration level in the serum significantly decreased on the 9th day in the Saryuktangkamibang-dosed group to which 0.6g/100g injected. 3. In the measurement for each dosage dates, the glucose concentration level in the serum significantly decreased on the 11th day in the Saryuktangkamibang-dosed group to which 0.6g/100g injected. 4. The AST concentration level in the serum significantly decreased on the 11th day in the Saryuktangkamibang-dosed group. Conclusion : Saryuktangkamibang, Saruktang with Liriopis Tuber, Lycii Fructus, Schizandrae Fructus, and Bombyx Batryticatus, has an effect of hypoglycemia, with no hepato-renal dysfunction. For the experimental results above, in that nephrotoxicity significantly decreased on the 0.6g/100g concentration, another research such as study for effect in other ranges and study for effect of dosage term except the concentration range of this study is necessary. Also dosage of appropriate concentration of Saryuktangkamibang is thought to provide valuable aid to cure on diabetes.

• Journal of Nutrition and Health
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• v.27 no.9
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• pp.883-891
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• 1994

The number of diabetics in Korea is about 3 to 5 percent of the population, and the incidence is increasing yearly due to changes of life style and food intake. Diet is a key element in the management of diabetes, yet the appropriate diet for diabetes remains controversial. We have recently shown that a diet rich in protein of animal origin(casein) seems beneficial to controling plasma glucose and lipids in streptozotocin-induced diabetic rats. It therefore seemed desirable to find out whether the beneficial effect of high casein diet in experimental diabetes could also be reproduced with a vegetable source of protein(soy). The purpose of this study is to compare these results with the results of our previous study. In the present study, non-diabetic and streptozotocin-induced diabetic rats were studied in order to examine the effects of altering the level(20% vs 60%) of dietary soy protein on blood glucose, lipids, and hormones. Results of the present study showed that a high soy protein diet decreased triglyceride concentration in diabetic rats. However, diabetic rats fed a high soy protein diet were not hypocholesterolemic compared to rats fed a control diet. Moreover, diabetic rats fed a high soy protein diet had significantly increased plasma glucose concentration compared to rats fed a control diet. This study was not able to discern a specific effect of dietary protein level on insulin, glucagon, or insulin/glucagon ratio. Except for the hypotriglyceridemic effect, the results were not similar to the findings of our previous study which showed a beneficial effect on streptozotocin-induced diabetic rats fed a high casein diet.

• The Korean Journal of Pharmacology
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• v.27 no.1
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• pp.1-5
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• 1991

We studied changes in the hypothalamic norepinephrine(NE) metabolism in streptozotocin (STZ)-induced diabetic rats by measuring basal NE levels, turnover rate of NE, and in vivo tyrosine hydroxylase activities. Basal NE level did not change significantly upto 4 weeks after the establishment of diabetes with STZ(60 mg/kg, iv). But turnover rate of NE decreased to 62% of control rate(P<0.01), and in vivo tyrosine hydroxylase activities decreased to 32% of control level(P<0.05) at one week of diabetes. From these results, we concluded that, of the three parameters measured, in vive tyrosine hydroxylase activity is the most sensitive index of altered hypothalamic NE metabloism in STZ-induced diabetic rats.

• Exercise Science
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• v.21 no.3
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• pp.289-298
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• 2012

In the present study, we investigated the effect of treadmill exercise on apoptotic neuronal cell death in the retinas of streptozotocin-induced diabetic rats. Twenty-eight male Sprague-Dawley rats were used for this study. The animals were divided into four groups(n = 7 in each group):(1) control group, (2) exercise group, (3) diabetes-induced group, (4) diabetes-induced and exercise group. Diabetes mellitus(DM) was induced by intraperitoneal injection of streptozotocin. The rats in the exercise groups were forced to run on the treadmill for 30 minutes once a day, five times per a week, during 12 weeks. In this study, a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) assay and western blot for the expressions of caspase-3, cytochrome c, Bax, and Bcl-2 in the retinas were conducted for the detection of apoptotic retinal cell death. The present results showed that the number of TUNEL-positive cells was increased in the retinas of the diabetic rats, whereas treadmill exercise suppressed this number. The expressions of pro-apoptotic factors caspase-3, cytochrome c, and Bax were enhanced and the expressions of anti-apoptotic factor Bcl-2 was decreased in the retinas of the diabetic rats. In contrast, treadmill exercise suppressed the expressions of caspase-3, cytochrome c, and Bax and increased the expression of Bcl-2. The present study demonstrated that treadmill exercise suppressed diabetes-induced apoptotic neuronal cell death in the retinas. Based on the present results, treadmill exercise may be effective therapeutic strategy for the alleviating complications of diabetes patients.