• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.256-262
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• 2009

Smallanthus sonchifolius (Yacon, Asteraceae) was originally cultivated in South America and used in food and traditional medicine by Andean inhabitants. Yacon is potentially beneficial for the management of diabetes and is composed of fructooligosaccharides, proteins, minerals and phenolic compounds. The aim of this study was to investigate the hypoglycemic effect of Yacon tuber extract (YTE) and its constituent, chlorogenic acid (CGA), in streptozotocin (STZ)-induced diabetic rats. In this study, a HPLC method was developed for simultaneous determination of major active phenolic components, CGA and caffeic acid in YTE. We investigated the hypoglycemic effect of YTE and CGA in STZ-induced diabetic rats and studied glucose tolerance test (GTT). The effect of orally administered multiple doses of YTE and CGA on plasma biochemical parameters was examined using diabetic rats. We also measured free radical scavenging activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Oral administration of YTE (200 mg/kg) and CGA (10 mg/kg) for 6 weeks produced a significant hypoglycemic effect in STZ-induced diabetic rats. YTE and CGA-treated groups exhibited significantly decreased plasma glucose surge during the GTT. Total cholesterol (TC) and triglyceride (TG) concentrations were significantly decreased by 33% and 49%, respectively, in YTE-treated rats. TC and TG concentrations were also significantly decreased by 26 % and 41%, respectively, in CGA-treated rats. In the DPPH assay, free radical scavenging activity of CGA was similar to that of vitamin E, a positive control. This study suggests that YTE and its constituent, CGA, may be a useful option for management of hyperglycemia and diabetic nephropathy.

• 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.

• Culinary science and hospitality research
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• v.17 no.1
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• pp.238-247
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• 2011

The aim of this study was designed to evaluate the effects of natural functional mixture(FM) on plasma BUN and lipid levels, hepatic lipid levels, hepatic antioxidant enzyme activities and plama aminotransferase activity in streptozotocin (STZ) induced diabe1ic rats. Total cholesterol (TC) level in the diabe1ic rats supplemented with FM(70.69 mg/dL) was reduced comparing to groups without FM(87.12 mg/dL). This results caused the increase of the ratio of HDL-cholesterol to TC (42.60 to 51.49 %). However, superoxide dismutase (SOD), cytosol catalase (CAT), glutathione peroxidase (GSH-Px), GSH and lipoperoxide (LPO) activities were not significantly changed, which indicated the supplementation with FM could not reduce the oxidative stress in diabetic rats. In addition, asperate aminotransferase (AST) activity in FM-diabetic rat was lower than that in diabetic group. This results showed supplementation with FM in rats could improve the hepatic function damaged by STZ-induced diabetes.

• Preventive Nutrition and Food Science
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• v.15 no.3
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• pp.167-175
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• 2010

This study was performed to explore the effects of the fermented functional extracts (FE) on blood glucose and lipid levels in diabetes. FE were created by mixing 9 kinds of plants with sea water and then allowing the mixture to ferment for 1 year. FE were supplemented in the feed of streptozotocin (STZ)-induced diabetic rats at 1%, 3% and 5%. The 1% feeding group showed the lowest weight loss of the three experimental groups. The blood glucose and glycosylated hemoglobin level were significantly decreased in the FE fed rats compared to the diabetic control (DMC) group. The lipid levels in serum were decreased in 1% and 3% FE fed rats in comparison to the DMC group, and there was no significant difference in triglyceride levels due to the FE concentration. The HDL-C level was significantly increased in rats with FE supplemented diets, compared to the DMC group. The levels of lipid peroxides in liver tissue were significantly decreased in FE fed diabetic rats, and the hepatic glycogen content was increased in rats receiving supplements. As a result of these studies, we believe 1% FE may be the optimum level for controlling blood glucose and alleviating hyperlipidemia in STZ-induced diabetic rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.653-658
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• 2004

Oxidative stress is currently suggested as a mechanism underyling diabetes. Accordingly, the present study was designed to evaluate the effect of Aralia elate water extracts (AEW) on activities of hepatic oxygen free radical generating and scavenging enzymes in streptozotocin (STZ)-induced diabetic rats. Male Wistar rats divided into nondiabetic group, diabetic group, and diabetic-AEW supplemented group. The extract was supplemented in 1.14% of raw Aralia elata/kg diet for 7 weeks. Diabetes was induced by injecting STZ (55 mg/kg BW, ip) once 2 weeks before sacrifying. The hepatic cytochrome P-450 content, xanthine oxidase and aminopyrine N-demethylase activities were significantly lowered in the diabetic group compared to the nondiabetic group. Whereas, the activities of aniline hydroxylase and oxygen free radical scavenging enzymes, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase and glutathione S-transferase, were significantly higher in the diabetic group than in the nondiabetic group. However, the supplementation of AEW normalized these enzyme activities in STZ-induced diabetic rats. When the AEW was supplemented with the diabetic rats, hepatic glutathione content was markedly elevated as well as lipid peroxide level was significantly lowered compared to those of the diabetic group. Thus, these results suggested that AEW supplement enhanced the activities of oxygen species metabolizing enzymes in STZ-induced diabetic rats.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.39-45
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• 2013

Objectives : This study was conduct to compare of histological changes on four target organs which related with diabetes in streptozotocin-induced diabetic rats. Methods : Diabetes was induced in male Sprague-Dawley rats by consecutive injection of streptozotocin (STZ) at different doses of 30, 40 and 50 mg/kg for 5 days. After 4 weeks, all rats were sacrificed, five different organs such as pancreas, liver, kidney, and lung were isolated and observed their histological changes by hematoxylin and eosin (H&E), Periodic acid-Schiff (PAS) and Masson's trichrome staining. The changes of body weight, blood glucose, and food and water intake were also measured. Results : The multiple administration of STZ was induced diabetes in rats with hyperglycemia, decrease of body weight, increase water and food intake, and histopathological changes of target organs, compared with those of normal rats in both dose-dependent and time-dependent manner. In histological analysis, pancreas was showed decrease of the islet numbers with beta-cell loss. Kidney showed morphological damage with glomerulus hypertrophy, and also lung was showed bronchial epithelial damage with inflammatory cells infiltration. In liver, the portal vein and hepatic artery could not observed, and showed inflammatory cell infiltration with liver fibrosis. Conclusions : These results suggest that the increase of the capacity of STZ, each of the more chronic disease, it can be seen that the damage was deep. Thus, evaluate the resulting drug appropriate depending on the purpose of the model is expected to be selected.

• The Journal of Korean Medicine
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• v.27 no.2 s.66
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• pp.155-170
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• 2006

Objectives : This study aimed to evaluate the hypoglycemic, hepatoprotective, and nephroprotective effects of 'Saengjinyanghyul-tang($Sh\={e}ngj\={i}ny\v{a}ngxu\`{e}-t\={a}ng$ : SJYHT)' in streptozotocin (STZ)-induced diabetic SD rat model. Methods : SJYHT extracts were once a day dosed for 28 days at a dosage 1000, 500, and 250mg/kg/5ml from 25 days after STZ-dosing, and the changes on blood glucose levels, liver and kidney weight, serum AST, ALT, BUN and creatinine levels were observed with histological changes on the liver and kidney. Results : Increased blood glucose levels, and diabetic hepatopathy & nephropathy including increased serum AST, ALT, BUN and creatinine levels, histological changes after STZ-dosing were dose-dependently reduced by SJYHT extract-dosing. Conclusions : 'SJYHT' water extracts have favorable hypoglycemic, hepatoprotective, and nephroprotective effects on the STZ-induced diabetic SD rats. Therefore, it is expected that 'SJYHT' has potential for use in the management of diabetes and diabetic complications.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.665-672
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• 2017

The anti-diabetic effect of dried-silkworm Dongchunghacho water extracts was investigated in streptozotocin (STZ)-induced diabetic rats. Seven-week-old SD rats were randomly assigned to six groups: normal control (NC) group, diabetic control (DC) group, water extracts of Paecilomyces japonica grown on a dried-silkworm (PJ-DS, 50 mg/kg) group, PJ-DS (250 mg/kg) group, water extracts of Cordyceps militaris grown on a dried-silkworm (CM-DS, 250 mg/kg) group, and water extracts of dried-silkworm (DS, 250 mg/kg) group. These groups were orally provided with sample dissolved in water respectively for four weeks after an injection of STZ (60 mg/kg, ip) followed by identification of diabetic control (DC) group. After four weeks, body weight of all diabetic groups was significantly lower than that of the normal control (NC) group, but among diabetic groups there were no significant differences. Blood glucose levels of the PJ-DS (50 mg/kg), PJ-DS (250 mg/kg), CM-DS (250 mg/kg) and DS (250 mg/kg) groups were reduced compared to the DC group by 3.0 percent, 18.5 percent, 6.9 percent and 13.1 percent, respectively. Concentration of total cholesterol and triglyceride in blood plasma were to some degree decreased in PJ-DS (250 mg/kg) and DS (250 mg/kg) groups compared to the DC group. According to these results dried-silkworm Dongchunghacho water extracts (PJ-DS) boost protection against STZ-induced toxicity.

• Natural Product Sciences
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• v.11 no.3
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• pp.155-159
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• 2005

The aqueous extract of Coscinium fenestratum was studied for its antioxidant status in STZ-nicotinamide induced type 2 diabetic rats at two dose levels of 250 mg/kg and 500 mg/kg. At the end of the experimental period, diabetic rats treated with aqueous extract at both dose levels showed a significant increase in the levels of enzymatic antioxidants such as glutathione peroxidase, glutathione synthetase, peroxidase, superoxide dismutase and catalase as compared to the untreated control. Similarly, a significant increase was also observed in the levels of the non enzymatic antioxidants ceruloplasmin, ascorbic acid and tocopherol. The results suggest that the aqueous stem extract of C. fenestratum prevents type 2 diabetes mellitus induced oxidative stress.

• Biomedical Science Letters
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• v.14 no.1
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• pp.63-68
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• 2008

The aqueous extract from the fruit body of Lentinus edodes was evaluated for inhibitory activities against $\alpha$-glucosidase isolated from Spargue-Dawley male rats. A aqueous extract of Lentinus edodes exhibited 13.8% inhibitory activity on using 2 mM p-nitrophenyl $\alpha$-D-glucopyranoside as a substrate ($IC_{50}$ 75.3 mg/ml). The aqueous extract of Lentinus edodes inhibition type on $\alpha$-glucosidase was determined to be competitive inhibition. When it was oral administered to increase of blood glucose levels after STZ-induced in a dose dependent dietary. These results suggest that aqueous extract of Lentinus edodes effect a metabolism of intestine, and thereby reducing the increase of blood glucose after STZ-induced.