• Journal of Nutrition and Health
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• v.44 no.4
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• pp.275-283
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• 2011

This study was conducted to evaluate the antihyperglycemic effects of three phytoestrogens, genistein, coumestrol, and enterolactone, in type 2 diabetic animals. Forty male C57BL/KsOlaHsd-db/db mice were used as a diabetic animal model. The animals were divided into four groups and fed a phytoestrogen-free AIN-76 diet (control), or one of three phytoestrogen-supplemented (3.75 mg/100 g diet) AIN-76 diets for six weeks. During the experimental period, fasting blood glucose levels were measured on week 0, 2, 5, and 6 of the experiment, and oral glucose tolerance tests were performed on the 5th week. After the experimental period, blood concentrations of HbA1c, insulin, and glucagon were measured, and hepatic glycogen content and glucose regulating enzyme activities were analyzed. Fasting blood glucose, HbA1c level, and the area under the blood glucose curve in the oral glucose tolerance test were significantly lower in all of the phytoestrogen-supplemented groups compared to the control group. Plasma glucagon levels were also significantly lower in all of the phytoestrogen-supplemented groups compared to the control group. Hepatic glycogen level was significantly higher in the coumestrol-supplemented group compared to the other groups. However, there were no significant differences in the activities of glucokinase and glucose-6-phosphatase between the groups. These results suggest that all of the three major phytoestrogens tested in the present study were effective in lowering blood glucose levels in type 2 diabetic animals. However, further studies need to be conducted to elucidate the exact mechanism for the hypoglycemic effects of phytoestrogens.

• Proceedings of the Korean Nutrition Society Conference
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• 2004.05a
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• pp.150-150
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• 2004

• Proceedings of the Korean Nutrition Society Conference
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• 2004.05a
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• pp.169-169
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• 2004

• Proceedings of the Korean Nutrition Society Conference
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• 2003.10a
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• pp.119-119
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• 2003

• Journal of Ginseng Research
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• v.44 no.2
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• pp.362-372
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• 2020

Background: The non-saponin fraction of Korean Red Ginseng has been reported to have many biological activities. However, the effect of this fraction on anti-diabetic activity has not been elucidated in detail. In this study, we investigated the effects of KGC05P0, a non-saponin fraction of Korean Red Ginseng, on anti-diabetic activity in vitro and in vivo. Methods: We measured the inhibition of commercially obtained α-glucosidase and α-amylase activities in vitro and measured the glucose uptake and transport rate in Caco-2 cells. C57BL/6J mice and C57BLKS/J^db/db (diabetic) mice were fed diets with or without KGC05P0 for eight weeks. To perform the experiments, the groups were divided as follows: normal control (C57BL/6J mice), db/db control (C57BLKS/J^db/db mice), positive control (inulin 400 mg/kg b.w.), low (KGC05P0 100 mg/kg b.w.), medium (KGC05P0 200 mg/kg b.w.), and high (KGC05P0 400 mg/kg b.w.). Results: KGC05P0 inhibited α-glucosidase and α-amylase activities in vitro, and decreased glucose uptake and transport rate in Caco-2 cells. In addition, KGC05P0 regulated fasting glucose level, glucose tolerance, insulin, HbA1c, carbonyl contents, and proinflammatory cytokines in blood from diabetic mice and significantly reduced urinary glucose excretion levels. Moreover, we found that KGC05P0 regulated glucose production by down-regulation of the PI3K/AKT pathway, which inhibited gluconeogenesis. Conclusion: Our study thereby demonstrated that KGC05P0 exerted anti-diabetic effects through inhibition of glucose absorption and the PI3K/AKT pathway in in vitro and in vivo models of diabetes. Our results suggest that KGC05P0 could be developed as a complementary food to help prevent T2DM and its complications.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.107-114
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• 2012

Objectives : In this study, we investigated the anti-diabetic and anti-inflammatory effects of water extract from leaves of Ligustrum japonicum (WLJ) in db/db mouse. Methods : The db/db mice were treated orally with WLJ (300 mg/kg/day) for 10 weeks to examine the long-term effects on hyperglycemia and glomerular tissue as well as biochemical and functional abnormalities in the kidney. Results : WLJ treatment markedly reduced plasma levels of glucose, triglyceride, creatinine, and systolic blood pressure in diabetic db/db mouse. Treatment of WLJ significantly increased plasma level of high density lipoprotein (HDL)-cholesterol. We also found that overexpressions of vascular cellular adhesion molecule (VCAM)-1 and endothelin (ET)-1 were observed in aortic tissue of db/db mouse, whereas, WLJ suppressed both expression of VCAM-1 and ET-1 in aorta. In renal tissue, overexpressions of ICAM-1 and TGF-${\beta}1$ were found in untreated db/db mouse, however, significantly decreased those levels by WLJ treatment. The insulin immunoreactivity of the pancreatic islets remarkably increased in WLJ treated db/db mouse compared with untreated db/db mouse. Taken together, WLJ treatment ameliorated hyperglycemia and hyperlipidemia via improvement of insulin secretion and lipid metabolism, respectively. Furthermore, WLJ treatment also ameliorated hypertension via inhibition of inflammatory process in vascular and renal tissues. Conclusions : Ligustrum japonicum has an anti-diabetic and anti-inflammatory effects in db/db mouse. Thus, these results suggested a beneficial effect of Ligustrum japonicum in treatment with diabetes and diabetic vasculopathy.

• Korean Journal of Pharmacognosy
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• v.31 no.3
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• pp.268-272
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• 2000

GE974, isolated from Gyrophora esculenta, showed significant inhibitory effect on several ${\alpha}-glucosidases$ in vitro in previous study. In the present study, GE974 showed significant inhibitory effect on blood glucose elevation in mice loaded with maltose, sucrose, starch and lactose. Also, it exhibited similar effect in alloxan and streptozotocin induced diabetic mice, and genetic diabetic mice(db/db mice) loaded with maltose in dose dependent manner. These results suggest that GE974 may possess hypoglycemic effect that inhibit competitively ${\alpha}-glucosidase$ activities.

• The Korean Journal of Food And Nutrition
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• v.21 no.4
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• pp.425-429
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• 2008

Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. Type 1 diabetes, or juvenile-onset diabetes, results from a cellular-mediated autoimmune destruction of the ${\beta}$-cells of the pancreas. Type 2 diabetes, or adult-onset diabetes, is a term used for individuals who have insulin resistance, a condition that makes it harder for the cells to properly use insulin, and usually have relative insulin deficiency. The diabetes causes the onset of chronic complications and diabetic neuropathy is one of the most debilitating complications. In this study, the hypoglycemic effect and the preventive effect of diabetic complications of Dioscorea rhizoma extract(DRE) were examined in rodent model. We investigated the glucose tolerance test and long term hypoglycemic effect of DRE in Type 1 streptozotocin-induced diabetic rats and Type 2 diabetic db/db mice. DRE showed a hypoglycemic effect on blood glucose levels than that of control group in Type 1 streptozotocin-induced diabetic rats and Type 2 diabetic db/db mice. On the basis of our results, we conclude that long-term use of DRE might help decrease blood glucose level and prevention of diabetes-associated complication.

• Nutrition Research and Practice
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• v.5 no.2
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• pp.107-111
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• 2011

The objective of this study was to investigate the hypoglycemic effects of quercetin (QE) in animal models of diabetes mellitus (DM). A starch solution (1 g/kg) with and without QE (100 mg/kg) or acarbose (40 mg/kg) was orally administered to streptozotocin (STZ)-induced diabetic rats after an overnight fast. Postprandial plasma glucose levels were measured and incremental areas under the response curve were calculated. To study the effects of chronic feeding of QE, five-week-old db/db mice were fed an AIN-93G diet, a diet containing QE at 0.08%, or a diet containing acarbose at 0.03% for 7 weeks after 1 week of adaptation. Plasma glucose and insulin, blood glycated hemoglobin, and maltase activity of the small intestine were measured. Oral administration of QE (100 mg/kg) or acarbose (40 mg/kg) to STZ-treated rats significantly decreased incremental plasma glucose levels 30-180 min after a single oral dose of starch and the area under the postprandial glucose response, compared with the control group. QE (0.08% of diet) or acarbose (0.03% of diet) offered to db/db mice significantly reduced both plasma glucose and blood glycated hemoglobin compared to controls without significant influence on plasma insulin. Small intestine maltase activities were significantly reduced by consumption of QE or acarbose. Thus, QE could be effective in controlling fasting and postprandial blood glucose levels in animal models of DM.

• Nutrition Research and Practice
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• v.10 no.3
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• pp.282-287
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• 2016

BACKGROUND/OBJECTIVES: Jerusalem artichoke has inhibitory activity against ${\alpha}$-glucosidase and decreases fasting serum glucose levels, which may be related to its fructan content. The biological activity of fructan can be influenced by the degree of polymerization. Thus, in this study, the inhibitory effects of original and fermented purple Jerusalem artichoke (PJA) on ${\alpha}$-glucosidase were compared in vitro. Additionally, the anti-diabetes effect of Lactobacillus plantarum-fermented PJA (LJA) was studied in a non-insulin-dependent diabetes mellitus animal model (C57BIKsJ db/db). MATERIALS/METHODS: The water extract of PJA was fermented by L. plantarum, and two strains of Bacillus subtilis to compare their anti-${\alpha}$-glucosidase activities in vitro by ${\alpha}$-glucosidase assays. The anti-diabetes effect of LJA was studied in a non-insulin-dependent diabetes mellitus animal model (C57BIKsJ db/db) for seven weeks. During the experiment, food intake, body weight, and fasting blood glucose were measured every week. At the end of the treatment period, several diabetic parameters and the intestinal ${\alpha}$-glucosidase activity were measured. RESULTS: The LJA showed the highest ${\alpha}$-glucosidase inhibitory activity in vitro. In the in vivo study, it resulted in a significantly lower blood glucose concentration than the control. Serum insulin and HDL cholesterol levels were significantly higher and the concentrations of triglycerides, non-esterified fatty acids, and total cholesterol were significant lower in mice treated with LJA after seven weeks. In addition, the intestinal ${\alpha}$-glucosidase activity was partially inhibited. CONCLUSIONS: These results suggested that LJA regulates blood glucose and has potential use as a dietary supplement.