• Food Science and Biotechnology
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• v.18 no.3
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• pp.808-812
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• 2009

The ${\alpha}-glucosidase$ inhibitory and antioxidant effects of water chestnut (Trapa japonica Flerov.) were assessed to explore its possible use as an anti-diabetic agent. Methanol extracts of the fruit shell and meat of water chestnut were assayed for inhibitory activity against yeast ${\alpha}-glucosidase$ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Effect of fruit shell extract on postprandial glucose response was assessed. Compared with fruit meat, shell extract showed stronger inhibition against ${\alpha}-glucosidase$ with an $IC_{50}$ of 273 ${\mu}g/mL$. Oral administration of fruit shell extract (500 mg/kg) significantly lowered the postprandial area under the glucose response curve to starch (1 g/kg) in streptozotocin (STZ)-induced diabetic rats (p<0.01). Compared with fruit meat, shell extract showed stronger scavenging activity against DPPH, with an $IC_{50}$ of 27.1 ${\mu}g/mL$. The results indicate that the fruit shell of water chestnut was effective in controlling postprandial hyperglycemia and exerted an antioxidant effect. Therefore, water chestnut may be useful in treating diabetes.

• Korean Journal of Pharmacognosy
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• v.34 no.3 s.134
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• pp.250-255
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• 2003

To develop Allium victorialis var. platyphyllum (Liliaceae) for an available functional food, pharmacological experiments on the extracts of this plant were undertaken in the rat treated with streptozotocin, poloxamer-407 and $CCl_4$. The two MeOH extracts were obtained from the leaves and the bulbs, respectively. The three agents, streptozotocin, poloxamer-407 and $CCl_4$, were treated to induce diabetes mellitus, hyperlipidemia and hepatic injury, respectively. Treatment with the leaf extract lowered blood glucose by 24.9% at 200 mg/kg (p.o.) in the STZ-treated rat and prohibited the increase of body weight, water consumption and food intake. This exσact also significantly decreased not only thε plasma cholesterol and triglyceride in the poloxamer-407-treated rat by 35.3% but also serum ALT by 49.0%. The potency was found by overall estimation on the experimental results as followings: 200 mg/kg leaf extract> 200 mg/kg bulb extract> 100 mg/kg leaf exσact> 100 mg/kg bulb extract. These results suggested that this plant might have the availability for a functional food. It was also suggested that the leaves are more effective than the bulbs for the functional vegetable, especially in hyperlipidemia and hepatic injury.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.204-209
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• 2010

This study was conducted to investigate the anti-diabetic activity of Kocat-D1, which is widely used in traditional medicine to treat diabetes in Shandong, China. Sprague Dawley rats (8 weeks of age) were separated into 4 groups: a normal control, streptozotocin (STZ)-induced diabetic rat group (DM control), Kocat-D1-1 (diabetic rat treated with 0.25 g/kg/day hot water extract), and Kocat-D1-2 (diabetic rat treated with 1 g/kg/day hot water extract). After eight weeks of treatment, the fasting blood glucose levels of the Kocat-D1-1 ($334.3{\pm}32.9\;mg/dL$) and Kocat-D1-2 group ($259.5{\pm}35.0\;mg/dL$) were significantly lower when compared to the DM control group ($451{\pm}42.6\;mg/dL$). Furthermore, the levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), albumin and high-density lipoprotein (HDL) cholesterol in the serum of the Kocat-D1-2 group were significantly normalized when compared to the DM control group. However, significant differences were not observed between the Kocat-D1-1 group and the DM control group. Histochemical staining of the liver of the Kocat-D1-2 group revealed no fat accumulation. The insulin level was significantly upregulated in the Kocat-D1-2 group ($0.13{\pm}0.02\;ng/mL$) when compared to the DM control group ($0.05{\pm}0.04\;ng/mL$). The relative volume of $\beta$-cells in the pancreas of the Kocat-D1-2 group ($49.4{\pm}4.2%$) also increased significantly when compared to the DM control group ($12.9{\pm}7.9%$). These results suggest that Kocat-D1 exerts an anti-hyperglycemic effect through the enhancement of insulin secretion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.840-846
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• 2002

Male Sprague-Bawler rats were blocked into four groups which were normal rats fed control diet (NC) diabetic rats fed control diet (DC), normal rats fed Hamcho powder diet (NH), and diabetic rats fed Hamcho powder diet (DH). Diabetes was induced by single injection of streptozotocin (60 mg/kg B.W. i.p.). The animals were fed ad libitum for 5 weeks. Malondialdehyde (MDA), glucose 6-phosphtase (Gspase), glutathione S-transferase (GST) glutathione Peroxidase (GPx), and glutathione reductase (GR) activities were measured in the homogenates of liver and kidney, and total lipid, total cholesterol, triglyceride, and HDL-cholesterol concentrations in the blood serum. Food and water intakes were markedly higher in diabetic groups than those of normal groups and were not significantly decreased by Hamcho powder supplementation, But, FER (Feed efficiency ratio) of DH Brood was higher than that of U group. Total cholesterol level of DH group was decreased in the second and third week, and the weekly change of blood sugar was also decreased in the 5th week. Dietary Hamcho intake showed 41.2% of hypoglycemic effect in diabetics rats. Levels of total lipid and triglycerides of DH group were lower than those of DC group. Hepatic GR activity of DH group was higher than those of other groups. However, renal GR activity was lower than those of other groups. Hepatic G6Pase activity was significantly high in DH group and reduced by Hamcho powder supplementation. GST was reduced by Hancho diet in diabetic rats. In conclusion Hamcho supplementation decreased serum lipid and glucose concentration in STZ-induced diabetic rats and this effects of Hamcho might exert antidiabetic effect of Hamcho powder diet.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.203-208
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• 2015

This study investigated the effect of Jerusalem artichoke (Helianthus tuberosus L.) extract on Blood Glucose and Lipid Metabolism in Streptozotocin (70 mg/kg B.W., i.p.)-induced Diabetic Rats. Sprague-Dawley male rats (200~220 g) were divided into normal control group (NC), diabetic control group (DC) and Jerusalem artichoke treated diabetic group (DJ). Diabetes was induced by single intraperitoneal injection of streptozotocin as a dose of 70 mg/kg body weight. Food (p<0.001) and water (p<0.05) intakes were higher in diabetic groups than the normal group. Body weight gain and food efficiency ratio were significantly lower in diabetic groups than normal group (p<0.01). However, they were higher in the DJ group than in the DC group. The serum levels of AST and ALT were significantly lower in the DJ group than in the DC group (p<0.05). The serum level of HDL-C was significantly higher in the DJ group than in the DC group (p<0.001). The serum levels of Triglyceride (p<0.05), LDL-C (p<0.001), and glucose (p<0.001) were significantly lower in the DJ group than in the DC group. At 3 and 4 weeks after the experiment, blood glucose level in the DJ group was significantly lower than the DC group (p<0.05). In conclusion, these results indicated that Jerusalem artichoke can prevent or retard the development of diabetic complications via its beneficial effects for alleviating the hyperglycemia and improved lipid metabolism.

• Journal of Life Science
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• v.14 no.5
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• pp.741-746
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• 2004

This study investigated the response of GLUT-4 and GRP-78 protein expression in soleus muscle of Streptozotocin-induced diabetic rats with caffeine oral administration by imposing different exercise intensities. Rats were randomly divided into 5 groups (n=6 in each group): diabetic group (D), diabetic-caffeine group (DC), diabetic-caffeine group with low intensity exercise (DCL), diabetic-caffeine group with moderate intensity exercise (DCM) and diabetic-caffeine group with high intensity exercise (DCH). The rats in DCL, DCM and DCH groups were exercised acutely by treadmill running for 8 meter/m, 16 meter/m and 25 meter/m, respectively. Little difference in GLUT-4 protein expression was shown in DC and DCL compared to D. GLUT-4 protein expression was decreased in DCM and increased in DCH was observed. GRP-78 protein expressions in DCL, DCM and DCH were little lower than that of D. An increase in GRP-78 protein was observed in DC. Improved insulin sensitivity with acute high intensity exercise gives the rats important therapy that lowers insulin requirement. This improvement of insulin sensitivity for glucose transport in skeletal muscle results from translocation of the GLUT-4 protein from the endoplasmic reticilum to the cell surface and increase in total quantity of GLUT-4 protein. It is not clear what mechanism reduced GRP-78 protein level in exercise group. It is merely conjectured that caffeine-induced lipolysis provided cells with energy in abundance and this relieved stress which cells are subjected to receive when performing exercise.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.6
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• pp.939-948
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• 2008

The effects of goat's beard (Aruncus dioicus var ramtschaticus Hara) ethanol extracts (AD) on the streptozotocin-induced diabetic symptoms and oxidative stress in rats were assessed. Experimental plots were divided into normal controls (NC), diabetes controls (DM), diet with 0.3% AD after diabetes induction (SA), and diet with 0.6% AD after diabetes induction (SB), then fed for 5 weeks. In the SA and SB groups as compared with the DM group, diabetic symptoms including weight loss, increase in feed and water intake, and enlargement of the liver and kidney were improved. The levels of blood glucose and serum fructosamine were reduced by $17.9{\sim}27.2%$ and $25.6{\sim}32.6%$, respectively. The activities of alanine aminotransferase, aspartate aminotransferase and the levels of triglycerides, total cholesterol, and LDL-cholesterol in the serum were reduced by $25.6{\sim}30.3$, $42.37{\sim}55.51$, $26.85{\sim}30.44$ and $37.29{\sim}39.11%$, respectively, whereas the level of HDL-cholesterol was increased by $37.29{\sim}39.11%$. Hepatic total (T) and O type (O) activities of xanthine oxidoreductase, O/T ratio(%) and level of lipid peroxide were significantly decreased, while the level of glutathione was increased, and also the activities of superoxide dismutase and glutathione S-transferase were increased by $56.84{\sim}94.90%$ and $57.14{\sim}68.92%$, respectively. In the above results, it was noted that AD has an antidiabetic effect which alleviated hyperglycemia and the AD reduced and/or prevented the tissue damage caused by diabetes yia the inhibition of reactive oxygen species (ROS) generating systems concurrent with an increase in ROS scavenging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.72-77
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• 2004

Diabetic vascular complications such as atherosclerosis have been reported as one of significant obstructions in treatment of diabetes. There has been a significant increase in recognition of the importance of antioxidative nutrients such as vitamin E, for the prevention of diabetic vascular complication by oxidative stress. This study focused on the effect of dietary $\beta$-carotene on the levels of lipid peroxide and antioxidative vitamins of diabetic rats. The plasma glucose level, hepatic level of lipid peroxide and contents of antioxidants such as vitamins A and E were determined in STZ-induced diabetic rats. Dietary supplementation of B-carotene did not reduce the blood glucose in diabetic rats. Hepatic level of lipid peroxide tended to increase in diabetic rats, but $\beta$-carotene intake reduced the value. Plasma levels of retinol and retinol/lipid were not changed by dietary supplementation of $\beta$-carotene. There was no significant difference among experimental groups in plasma level of $\alpha$-tocopherol. Hepatic levels of retionl and retinyl palmitate were increased by dietary supplementation of $\beta$-carotene in diabetic rats. These results suggest that the supplementation of $\beta$-carotene to the normal diet of diabetics may reduce the incidence of the diabetic vascular complications through the improvement of antioxidants depletion.

• Journal of Life Science
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• v.28 no.4
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• pp.421-428
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• 2018

Postprandial hyperglycemia plays an important role in the development of Type 2 Diabetes and diabetic complications. Controlling postprandial hyperglycemia is the most important factor for reducing the risks of diabetic complications in Type 2 diabetic patients. This study was designed to determine whether Portulaca oleracea L. extract suppresses the activation of carbohydrate-digesting enzymes, and lowers postprandial hyperglycemia in diabetic mice through streptozotocin. P. oleracea was extracted with either 80% ethanol (PEE) or water (PWE), and the extract solutions were concentrated. The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibition assays were performed using the chromogenic method. Normal mice and STZ-induced diabetic mice were orally treated with PEE, PWE (300 mg/kg of body weight) or acarbose (100 mg/kg of body weight), with soluble starch (2 g/kg of body weight). The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory effectiveness by PEE were markedly more effective than PWE, and both extracts indicated a higher effectiveness than the acarbose (positive control). The rise in postprandial blood glucose due to starch loading was markedly inhibited in the PEE group when compared to the control group in diabetic and normal mice. Furthermore, the area under the concentration-time curve values were markedly declined by the PEE injection in the diabetic group when compared to that exerted for the control group. These results demonstrate that P. oleracea extracts lower postprandial hyperglycemia by inhibiting carbohydrate-digesting enzymes, and that the ethanol extract is more efficacious than the water extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.987-994
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• 2004

The purpose of this study was to investigate the effect of dietary seaweed in diabetic rats treated with streptozotocin (STZ) for 7 weeks. The rats (Sprague-Dawley male rats, 180∼200 g) were divided into 4 groups : normal rats fed control diet (C), diabetic rats fed control diet (CD), normal rats fed seaweed diet (M), and diabetic rats fed seaweed diet (MD). Diabetes was induced by single injection of streptozotocin (60 mg/kg, i.p.). Urinary levels of calcium and uric acid, and blood levels of hemoglobin, total cholesterol and low density lipoprotein (LDL)-cholesterol were not significantly different among groups. But high density lipoprotein (HDL)- cholesterol of M and MD groups were higher than that of C and CD groups. Activity of hepatic microsomal G6Pase was significantly (p<0.05) lower in C and M groups than that of CD and MD groups. Hepatic glutathione S-transferase (GST) of M, CD and MD groups were significantly lower than C group (p<0.05), glutathione peroxidase (GPX) of C, M and MD groups were higher than CD group. In conclusion, dietary seaweed may improve blood lipid profiles and GSH-related enzymes in STZ-induced diabetic rats.