• 한국식품영양과학회지
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• 제26권5호
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• pp.901-907
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• 1997

The purpose of this study was to investigate the effects of green tea catechin o n free radical generation system and peroxidative damage in the liver of streptozotocin(STZ)-induced diabetic rats. Spragu-Dawley male rats weighing 150$\pm$10gm were randomly assigned to one normal and three STZ-induced diabetic groups; diabetic groups were classified to catechin free diet(DM-oC group), 0.5% catechin diet(DM-0.5C group) and 1% catechin diet(DM-1C group) according to the levels of dietary catechin supplementation. Diabetes was experimentally induced by intravenous injection of 55mg/kg of body wt of STZ in citrate buffer(pH 4.3) after feeding of three experimental diet for 4 weeks. Animals were sacrificed at the 6th day of diabetic states. Activities of serum glutamic oxaloacetic transaminase(GPT) in DM-oC groups were higher than those of the normal group, and those in catechin supplementation group were similar to those of the normal group. Liver lipid peroxide values increased by 153%, 49%, and 27% in Dm-oC, DM-0.5C and DM-0C and Dm-1C but was not significantly different in catechin supplementation groups compared with the normal group, and liver cytochrome $P_{450}$ contents was similar to result of XOD activity. In electron microscopic examination of liver, lysosome was relatively scattered in Dm-oC and Dm-0.5C group and preserved normal shapes in DM-1C group. The present results indicate that STZ-induced diabetic rats are more sensitive to oxidative stress, leading to the acceleration of lipid peroxidation process, but this was reduced by anti-oxidative effect of high level of dietary catechin. It is concluded that dietary catechin serves as powerful antioxidant against lipid peroxidation in diabetic rats.

• Clinical and Experimental Reproductive Medicine
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• 제43권2호
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• pp.90-96
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• 2016

Objective: Diabetes mellitus (DM) is known to cause many systemic complications as well as male infertility. Astaxanthin (ASTX) is a powerful antioxidant that is involved in a variety of biologically active processes, including those with anti-diabetes effects. The present study investigates the effect of ASTX on the spermatozoa function in streptozotocin (STZ)-induced diabetic rats. Methods: We divided 30 adult rats into three groups (10 rats per group), with a control group that received corn oil mixed with chow. DM was induced by intra-peritoneal injection of STZ. Eight weeks after the STZ injection, half of the diabetic animals were used as diabetic controls, and the rest were treated with ASTX for 56 days. Then the parameters and chromatin integrity of the epididymal sperm were analyzed using chromomycin A3, toluidine blue (TB), and acridine orange (AO) staining. Results: The count, viability, and motility of the epididymal sperm were decreased significantly in the STZ group in comparison with the control group (count and viability, p<0.001; motility, p<0.01). ASTX increased normal morphology and viable spermatozoa compared to the STZ group (morphology, p=0.001; viability, p<0.05). The percentage of abnormal chromatins in TB and AO staining was higher in the STZ group compared to the control group (p<0.001). The mean percentage of TB and AO positive spermatozoa in STZ rats was significantly lower in the STZ+ASTX group (TB, p=0.001; AO, p<0.05). Conclusion: This study observed that in vivo ASTX treatment partially attenuates some detrimental effect of diabetes. Conversely, ASTX improved sperm viability, normal morphology, and DNA integrity.

• The Korean Journal of Pain
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• 제14권1호
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• pp.12-18
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• 2001

Background: It is controversial whether the change in nitric oxide (NO) expression in the dorsal root ganglia (DRG) may be responsible for developtment and/or maintenance of painful diabetic neuropathy. The aim of this study was to clarify the role of NO in the pathogenesis of painful diabetic neuropathy. Methods: The effect of L-nitroargine methylester (L-NAME) or sodium nitroprusside (SNP) on allodynia was measured in streptozotocin (STZ)-induced diabetic rats. NO concentration was measured in the cerebrospinal fluid (CSF) and plasma of the diabetic rats. NADPH-diaphorase (NADPH-d) histochemistry was performed on the DRG and spinal cords of the STZ-induced diabetic rats. Results: L-NAME, an inhibitor of nitric oxide synthase, alleviated allodynia, while SNP, a nitric oxide donor, aggravated allodynia in diabetic rats. Plasma NO level in the diabetic rats was significantly decreased compared with control rats. NO level in the CSF of diabetic rats did not differ from that of the control rats. NADPH-d positive cells were decreased in the DRG of diabetic rats. However, NADPH-d histochemistry in the diabetic spinal cord was not different from that of the control rats. Conclusions: Downregulation of NO expression in the diabetic rats may not be causally related to the development and/or maintenance of painful diabetic neuropathy.

• Journal of Nutrition and Health
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• 제29권1호
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• pp.22-31
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• 1996

The purpose of this study was to investigate the effect of vitamin E and selenium on the antioxidative defense mechanism in the liver of streptozotocin(STZ)-induced diabetic rats. Sprague-Dawley male rats(120$\pm$10gm) were randomly assigned to one control and five STZ-diabetic groups. Diabetic groups were classified to STZ-0E (vitamin E free diet), STZ-40E(40mg vitamin E/kg of diet), STZ-400E(400mg vitamin E/kg of diet), STZ-S(0.5ppm Se/kg of diet) and STZ-400ES(400mg vitamin E and 0.5ppm Se/kg of diet) according to the level of vitamin E and selenium supplementation. Diabetes was experimentally induced by intravenous adminstration of 55mg/kg of STZ in citrate buffer(pH 4.3) after 4-weeks feedng of six experimental diets. Animals were sacrificed at the 4th day of diabetic states. Activities of the serum glutamic oxaloacetate transaminase(GOT) and the glutaminc pyruvate transaminase(GPT) in STZ-0E, STZ-40E and STZ-S rats were higher than those of control. Liver xanthine oxidase activities were similar to serum GOT and GPT. Liver superoxide dismutase(SOD) activities were higher in STZ-0E and STZ-40E groups by 33%, 22%, respectively than that of control. Glutathione S-transferase(GST) activities of liver were similar to GSH-Px activities. The contents of vitamin E in liver tissue were significantly lower STZ-0E, STZ-40E and STZ-S groups by 50%, 36%, 45% than that of control. Reduced glutathione(GSH) contents of liver were lower STZ-0E, STZ-40E, STZ-400E, STZ-S and STZ-400ES groups by 57%, 51%, 19%, 18%, 12% than that of control. Lipid peroxide values (LPO) in liver were higher 5.6, 2.3 and 2.3 times in STZ-0E, STZ-40E and STZ-S group than that of control. The present results indicate that STZ-induced diabetic rats are more sensitive to oxidative stress, leading to the acceleration of lipid peroxidation process, which can be more accelerated by feeding the low level of dietary vitamin E. In the coincident supplementation of high dietary vitamin E and selenium antioxidative enzymes activities and physiolosical antioxidants were increased more than those of the separate supplementation of vitamin E or selenium. Therefore, dietary vitamin E and selenium reduced peroxidative damage of tissue, promoting antioxidative defense mechanism against lipid peroxidation by diabetes.

• 한국응용과학기술학회지
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• 제25권3호
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• pp.347-354
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• 2008

This study was done to investigate the antidiabetic effect of polygoni radix in Streptozotocin(STZ)-induced diabetic rats. Diabetes was induced by intravenous injection of STZ at a dose of 45mg/kg dissolved in citrate buffer. The ethanol extract of polygoni radix was orally administrated once a day for 7 days. The content of serum glucose, triglyceride(TG), total cholesterol were significantly decreased in polygoni radix treated STZ-sample group compared to the those of STZ-control group. The content of hepatic glycogen and activities of glucose-6-phosphate dehydrogenase(Glucose-6-PDH), glucokinase were significantly increased, but activity of glucose-6-phoshatase was decreased in polygoni radix treated STZ-sample group compared to the those of STZ-control group. These results indicated that ethanol extract of polygoni radix would have antidiabetic effect in STZ-induced diabetic rats.

• 대한예방한의학회지
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• 제10권1호
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• pp.75-93
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• 2006

Rhus verniciflua Stokes(RVS) has been widely used as a food and traditional herbal medicine in Korea. RVS has been reported that the extract from its wood and fruit has strong antioxidant activity and anticancer effect but there is little information on Lacca Sinica Exsiccata(LSE), the resin of RVS, as a medicinal use. The aim of this study was to evaluate the antidiabetic effect of ethanol-eluted extract of LSE on streptozotocin(STZ) - induced diabetic rats. Diabetes was induced in male Sprague-Dawley rats with STZ injection. Oral administration of LSE extract(50mg or 100mg/kg of body weight/day) was given to diabetic group. During 4 weeks of experiment, diabetic rats showed significant weight loss and decreasing feed efficiency ratios(FER) compared with normal rats, while the diabetic group orally fed with LSE extract showed a trend of decreasing weight loss and a significant increase of FER(p<0.05). In 4 weeks after induction of diabetes, diabetic rats showed an increase in weight of liver, kidney and heart, whereas the diabetic rats administered with LSE extract showed a reduction in the weight of heart. Blood glucose level was decreased in diabetic rats treated with LSE extract, but it was not statistically significant. Glutamic oxaloacetic transaminase, Glutamic pyruvate transaminase and total cholesterol levels were lower in the diabetic group treated with LSE extract than in untreated diabetic group, but not significant. These results present that LSE may partly have antidiabetic effect and may protect against the development of diabetic heart complications resulting from impaired glucose metabolism.

• 한국식품조리과학회지
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• 제18권3호
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• pp.300-308
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• 2002

The purpose of this study was to investigate the effect of chloroform(CHC1$_3$) fraction of Alisma canaliculatum All. Braun et Bouche(Ac) with selenium(Se) on the plasma glucose and lipid levels in streptozotocin(STZ)-induced diabetic rats. Male Sprague-Dawley rats were divided into five groups. The normal and diabetic rats were separated into four groups: the STZ-control group, the Ac group, the Ac-Se group and the Se group. Diabetes was induced in the male rats by an injection of STZ into the tail vein at a dose of 45 mg/kg. The CHCl$_3$fraction of Ac(250 mg/kg) was administered orally for 14 days. The supplementation was achieved with the AIN-93 recommended diet by adding 2 mg/kg diet of selenium as Na$_2$SeO$_3$. which was prepared freshly everyday. The body weight, hematocrit(Hct), glucose, insulin, cholesterol, HDL-cholesterol, triglyceride(TG) and free fatty acids(FFA) concentrations in plasma were measured. The aminotransferase activities were also analyzed. The changes of body weight in the experimental groups were not significantly different from that of the STZ-control group, but diabetes hyperphagia accompanied changes with body weight loss in Ac-Se group. The levels of Plasma cholesterol were not significantly different among the experimental groups. The concentrations of FFA in the Ac-Se group increased significantly compared with the STZ-control group. The effect of Se alone significantly increased aspartate aminotransferase activity and alanine aminotransferase activity. The results showed that the treatment of CHCl$_3$fraction of Ac in combination with Se has no synergistic effect. There was a tendency for the plasma glucose levels to decrease when Se was administered into diabetic rats. Supplementation of Se in diabetic rats did not elicit a significant increase in plasma insulin levels and exhibited hypotriglyceridemic effect.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.261.2-261.2
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• 2002

Hypoglycemic effect of GRA was examined in multiple low dose(MLD) streptozotocin(STZ)-induced diabetic rats with regard to time of administration. Experimental methods: 20 mg/kg of STZ in 100 mM citrate buffer(pH 4.5) was injected intraperitoneally for 5 consecutive days. In co-treatment groups, GRA was administered intraperitoneally for 3 weeks at dose of 150 or 300 kg/kg. (omitted)

• 한국조리학회지
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• 제17권1호
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• pp.238-247
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• 2011

본 실험은 streptozotocin(STZ)으로 당뇨병이 유도된 쥐의 혈장 요소질소량, 지질수준 및 간 지질수준, 간 효소 활성에 천연 기능성 소재 화합물이 미치는 영향을 평가하는 것이 목적이었다. 총 콜레스테롤은 기능성 소재를 보충 급여한 실험군에서 유의적으로 낮은 수치(70.69 mg/dL)를 보였으며, 이로 인해 총 콜레스테롤에 대한 HDL 콜레스테롤의 비율이 증가(42.6에서 51.5%로) 하였다. 그러나, SOD, CAT, GSH-Px, GSH 및 LPO 활성에는 변화가 없었으며, 이는 기능성 소재의 보충 급여가 당뇨 쥐의 산화적 스트레스에는 큰 영향을 주지 않음을 의미한다. 보충 급여가 당뇨 쥐의 AST 수치 감소시켰으며, 이는 천연 기능성 소재 화합물 섭취가 간 기능 손상을 입은 STZ 유발 당뇨 쥐에 회복작용을 함을 알 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제7권1호
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• pp.39-45
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• 2003

Reactive oxygen species (ROS) have been suggested to be contributory factors in complications of diabetes mellitus. In the present study, we investigated the generation of superoxide, the lipid peroxide level measured as thiobarbituric acid reactive substances, the vasorelaxation of isolated thoracic aorta and the iNOS expression in kidney of streptozotocin induced diabetic rats. Sprague Dawley rats were divided into four groups: control, ascorbate (400 mg/kg rat weight daily in drinking water), diabetic (single dose of 50 mg of STZ/kg i.p.) and diabetic simultaneously fed with ascorbate for 12 wk. Rats in groups were studied at tri-weekly intervals (0 to 12 wk). Diabetic rats were evaluated periodically with changes of plasma glucose levels and body weight. The ascorbate supplimentation attenuated the development of hyperglycemia and weight loss induced by STZ injection in rats. In the present experimental condition, the ascorbate supplimentation had no significant effect on plasma glucose levels and changes in body weight of normal rate. The superoxide generation, formation of thiobarbituric acid reactive substance and iNOS expression in kidney were significantly increased in STZ-treated rats that were decreased by ascorbate supplimentation. The ascorbate supplimentation had no effect on vasorelaxation of isolated thoracic aorta. These results indicate that ascorbate supplimentation may exert an inhibitory effect on STZ-induced oxidative tissue damage through protection of pancreatic islet cells by scavanging reactive oxygen species. The ascorbate supplimentation may possibly attenuate the renal complication of diabetes mellitus.