• Food Science and Preservation
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• v.21 no.4
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• pp.549-559
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• 2014

This study investigated the hypoglycemic effects of mulberry leaf (M), green tea (G), and a mixture of mulberry leaf and green tea (MG) in rats with streptozotocin-induced diabetes. Male Sprague-Dawley rats were divided into the non-diabetic (N) and diabetic groups. The experimental animals were divided into four groups and fed the following for four weeks: a normal diet (N), the STZ+normal diet (STZ), the STZ+5% mulberry leaf (STZ-M), STZ+5% green tea (STZ-G), and the STZ+5% mixture of mulberry leaf and green tea (STZ-MG). The whole blood glucose level of the STZ-M, STZ-G and STZ-MG groups significantly decreased compared to the STZ group two weeks later. The serum glucose and fructosamine, and urine glucose levels in the STZ-M, STZ-G and STZ-MG groups were lower than in the STZ group. The levels of serum insulin were higher in the STZ-M, STZ-G and STZ-MG groups than in the STZ group. However, serum glucose, fructosamine and insulin levels, and urine glucose levels were not significantly different among the STZ-M, STZ-G and STZ-MG groups. These results indicate that mulberry leaf, green tea, and their mixture help prevent or attenuate the progression of diabetes in rats with STZ-induced diabetes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.183-194
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• 1995

The purpose of this study was to investigate the effect of vitamin E on the synthesis of the metallothionein in the liver of streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats($220{\pm}10mg$) were randomly assigned to one control and three STZ-diabetic groups. Diabetic groups were classified to STZ-0E(vitamine E free diet), STZ-40E(40mg vitamin E/kg of diet) and STZ-400E(400mg vitamin E/kg of diet) according to the level of vitamin E supplementation. Blood glucose levels of STZ-diabetic rats were three times higher than that of control. The contents of vitamin E in liver were lower signifciantly STZ-0E, STZ-40E groups by 50%, 36% compared with that of control. Lipid peroxide values(LPO) in liver were higher 5.6 and 2.5 times in STZ-0E and STZ-40E groups than that of control. Plasma cortisol levels were higher STZ-0E and STZ-40E groups compared with those of control, but cortisol levels were lower significantly in STZ-400E group compared with those of the STZ-0E and the STZ-40E groups. The plasma insulin levels were lower in all three STZ-diabetic group compared with that of control, but were not affected by the level of dietary vitamin E. The metallothionein (MT) contents in liver, kidney and small intestine were five times higher in STZ-0E, STZ-40E and STZ-400E compared with that of control, but STZ-400E group was lower in the MT contents in tissues compared with that of STZ-40E group. Zn-MT peak in STZ-diabetic rats liver increased than that of control by Sephadex G-75, and Zn-MT peak divided into MTI and MTII peaks by DEAE Sephadex A-25 column chromatography. 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 promoted low level of dietary vitamin E. And the result may that increase synthesis of MT induced in the liver of diabetic rats increased so it can be sure that the diabetes is one of the MT induce factor by free radical generation. And high vitamin E supplementation reduced total MT contents of liver, kidney and small intestine and the peak of purified Zn-MT. Through the results of these experiments, we can conclude that MT might be the free radical scavenger.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.4
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• pp.399-407
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• 2017

The purpose of this study was to examine the effect of Allium hookeri (AH) root on hepatic antioxidative enzyme contents in streptozotocin (STZ)-induced rats. Diabetes mellitus was induced in male Sprague-Dawley rats through injection of STZ dissolved in citrate buffer into tail veins at a dose of 45 mg/kg body weight. Sprague-Dawley rats were fed an AIN-93 recommended diet, and the experimental groups were fed a modified diet containing 5% and 10% of AH root powder for 4 weeks. The experimental groups were divided into four groups: a normal control (N-control), STZ-control, STZ-AH 5%, and STZ-AH 10% supplemented groups. The STZ-AH 5% group showed a significant increase in liver glycogen compared to the STZ-control group. Muscle glycogen and liver protein contents significantly increased in the AH-supplemented groups compared to the STZ-control group. The liver malondialdehyde content of the AH-supplemented group was significantly lower than that of the STZ-control group. Xanthine oxidase content was significantly reduced in all experimental groups. Glutathione-S-transferase content was significantly elevated in the AH-treated groups compared to the STZ-control group. Superoxide dismutase content was not significantly different among the experimental groups. Catalase content was significantly higher in the STZ-AH 10% group compared to the STZ-control group. These results show that supplementation with AH root may be useful for diabetic therapy and damage from oxidative stress.

• Journal of Haehwa Medicine
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• v.29 no.1
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• pp.18-25
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• 2020

Objective: The goal of this study is to investigate whether peripheral axonal regeneration is affected by diabetes in experimental animals. Method: Sprague Dawely rat was injected with 45~50 mg/kg of streptozotocin (STZ) to generate an animal model of diabetes. Three months after STZ injection, sciatic nerve (2 cm length) was removed and the same length of nerve segments from STZ-injected animal or from control animal (CTL) was transplanted into STZ-injected animals (STZ-STZ and STZ-CTL respectively). Similarly, sciatic nerve segments from STZ-injected animal or from control animal were grafted into the control animals (CTL-STZ and CTL-CTL respectively). All animals were sacrificed 2 weeks after transplantation. Sciatic nerve sections were prepared and subjected to immunofluorescence staining analysis. Results: Immunofluorescence staining for NF-200 showed that distal elongation of regenerating axons reached 40~80% of proximal neve in both CTL-STZ and CTL-CTL groups. However, distal elongation in both STZ-STZ and STZ-CTL groups were 20~60% of proximal nerve. Furthermore, measurement of axonal regeneration after immuno-staining with SCG10 showed that the scores of distal elongation relative to proximal nerve were 50~90% in CTL-CTL and CTL-STZ groups and 10-60% in STZ-CTL and STZ-STZ. Conclusions: Our data showed that the levels of axonal regeneration were not affected irrespective of whether they were from STZ- or CTL graft, but were greatly reduced when the nerves were transplanted into the STZ host.

• Journal of Nutrition and Health
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• v.29 no.1
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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.

• The Korean Journal of Community Living Science
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• v.27 no.1
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• pp.19-29
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• 2016

This study examined the anti-diabetic effects of young barley leaf powder in rats with streptozotocin (STZ)-induced diabetes. Male Sprague-Dawley rats were divided into the non-diabetic (N) and diabetic groups, and fed the following for four weeks. The diabetic groups were further subdivided into three experimental groups: a diabetic control group (STZ), a diabetic group fed 5% barley leaf powder (STZ-BL), and a diabetic group fed 10% barley leaf powder (STZ-BH). Food and water intakes were higher in the diabetic groups than in the N group. Body weight gain was higher in the STZ-BL and STZ-BH groups compared with the STZ group, but there were no significant changes in body weight gain between the diabetic groups. The serum glucose and fructosamine levels were lower in the STZ-BL and STZ-BH groups than in the STZ group. The levels of serum insulin were higher in the STZ-BL and STZ-BH groups than in the STZ group. Serum ALT, AST and ALP activities decreased in the STZ-BL and STZ-BH groups compared with the STZ group, but there was no difference. These results indicate that dietary supplementation of barley leaf powder can attenuate clinical symptoms of diabetes in rats with STZ-induced diabetes.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.6
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• pp.481-490
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• 2016

This study was designed to examine the effects of Allium hookeri (AH) on plasma blood glucose and fat profile levels in diabetic rats. Diabetes mellitus was induced in male Sprague-Dawley rats through injection of streptozotocin (STZ) dissolved in citrate buffer into tail veins at a dose of 45 mg/kg of body weight. Sprague-Dawley rats were then fed for 4weeks, with the experimental groups receiving a modified diet containing 5% or 10% powder derived from AH roots. The experimental groups were divided into four groups, consisting of a control group, STZ-control group, and diabetic fed with AH 5% & 10% treated groups. Rats' body weights, blood glucose, total cholesterol, HDL-cholesterol, triglyceride (TG), and free fatty acid (FFA) values in plasma were measured along with hematocrit (Hct) values and aminotransferase activities. Body weight losses were observed in the STZ-control group, whereas the STZ-AH group of diabetic rats gained weight. There was a significantly decrease in brain weight of the STZ-AH group but no significant differences in kidney and liver weights of the STZ-AH 5% & STZ-AH 10% groups compared to the STZ-control group. Blood glucose was significantly reduced in the STZ-AH 5% & STZ-AH 10% diabetic groups. There were no significant differences in total cholesterol and TG levels among the diabetic groups. HDL-cholesterol significantly increased while FFA significantly decreased in the STZ-AH 5% & STZ-AH 10% diabetic groups. The Hct level of the STZ-AH group was lower than that of the STZ-control group. Aspartate aminotransferase activity was significantly reduced in the STZ-AH 5% & STZ-AH 10% diabetic groups. These results indicate that supplementation with Allium hookeri root may have beneficial effects on diabetic complications as a potential therapeutic candidate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.621-629
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• 2012

This study investigated the effect of soybeans, $chungkukjang$, and $doenjang$ on blood glucose and serum lipid profile in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats weighing 205 g were divided into non-diabetic and diabetic groups. The diabetic groups were further subdivided into four experimental groups: a normal group (N), a diabetic control group (STZ-C), a diabetic group fed autoclaved soybean powder (STZ-S), a diabetic group fed $chungkukjang$ powder (STZ-CKJ) and a diabetic group fed $deonjang$ powder (STZ-DJ). Food and water intakes were higher in the diabetic groups than in the N group. The body weight gain and food efficiency ratios were higher in the STZ-S, STZ-CKJ, and STZ-DJ groups than in the STZ-C group, but created no significant changes between the diabetic groups on food intake and body weight gain. The whole blood level at 4 weeks of the STZ-CKJ group was significantly lower than the STZ-C group. Serum glucose levels of the STZ-S, STZ-CKJ, and STZ-DJ groups were significantly lower than the STZ-C group, but there was no significant change in serum insulin levels. The AST and ALP activities in serum were markedly higher in the STZ-C group, but these decreases in relation to diabetes increased in the STZ-S, STZ-CKJ, and STZ-DJ groups. The level of serum triglycerides was lower in the STZ-CKJ and STZ-DJ groups than in the STZ-C group, whereas level of serum HDL-cholesterol was higher in the STZ-CKJ and STZ-DJ groups. Levels of total serum and LDL-cholesterol were higher in the diabetic groups compared with the N group, but significantly decreased in the STZ-S, STZ-CKJ, and STZ-DJ groups compared to the STZ-C group. These results indicate that dietary supplements of soybean, $chungkukjang$ and $doenjang$ may improve blood glucose and lipid metabolism and help prevent or attenuate the progression of diabetes in STZ-induced diabetic rats.

• Applied Microscopy
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• v.43 no.2
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• pp.54-64
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• 2013

The study examined the antioxidant activities and anti-inflammatory effects of rutin from the streptozotocin (STZ)-induced diabetic rats. Results revealed that the levels of plasma glucose and serum glucose were remarkably higher in the STZ-treated group compared to other groups and were significantly reduced in the STZ+rutin treated group compared to the STZ-treated group. In terms of weight, it significantly increased in all experimental groups during the experiment period except for STZ-induced diabetic group. The weight of the STZ-treated group was remarkably reduced compared to other groups. Regarding the weight of each body organ, the STZ-treated group showed higher organ weight compared to the other groups while STZ+rutin-treated group showed significantly reduced kidney and liver weights compared to those of STZ-treated group. In the pancreas tissue of the STZ-treated group, ${\beta}$-cell destruction and vacuolization were observed. Inflammation in the heart, liver, kidney, and retina tissues were also vividly recorded. In the STZ+rutin administered group, the heart and retina tissues were shown to be preserved normally while the liver and kidney tissues showed reduced histopathology in general compared to the STZ-treated group. Conclusionally, the rutin has the effect on the antioxidant activities and anti-inflammation in the STZ-induced diabetic rats.

• The Korean Journal of Food And Nutrition
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• v.22 no.2
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• pp.246-251
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• 2009

This study examined the possible hypoglycemic effects Angelica gigas Naki extracts in streptozotocin-induced diabetic rats(STZ+50%, STZ+100% EtOH and STZ+water). The studies showed that administration of the Angelica gigas Naki extract decreased high blood glucose levels(more than 300 mg/$d{\ell}$) to a normal level(104 mg/$d{\ell}$) in the STZ+50% EtOH group. Liver glucokinase levels were significantly increased in STZ+50% EtOH and STZ+100% EtOH groups compared to the STZ group. Moreover, the liver acetyl CoA carboxylase level was significantly increased in STZ+50% EtOH, STZ+100% EtOH and STZ+water groups compared to the STZ group. These results suggest that the Angelica gigas Naki extract in the STZ+50% EtOH group exerted an ameliorable effect and can be used as an anti-diabetic substance, either as a dietary supplements or as a new drug.