• Journal of Nutrition and Health
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• v.43 no.4
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• pp.333-341
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• 2010

The aim of this study was to investigate the hypolgycemic activity of water extract of fermented yacon (Smallanthus sonchifolius) leaves tea (Yacon LWE) in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic mice. Male ICR mice were fed with a HFD (37% calories from fat) for 4 weeks prior to intraperitoneal injection with STZ (100 mg/kg body weight). Diabetic mice were supplemented with two doses of Yacon LWE (0.16% and 0.8%, wt/wt) for 6 weeks. The supplementation of high-dose Yacon LWE significantly lowered blood glucose levels and plasma ALT and AST activities compared with the control group. High-dose Yacon LWE also improved the insulin tolerance without any changes in plasma and pancreatic insulin concentrations in HFD/STZ-induced diabetic mice. Yacon LWE supplementation increased the insulin staining of pancreatic $\beta$-cells in a dose-dependent manner. Both 0.16% and 0.8% of Yacon LWE significantly elevated plasma leptin concentration, hepatic glucokinase activity and glucokinase/glucose-6-phosphatase ratio compared with the control group. However, glycosylated hemoglobin concentration was not different among the groups. These results suggest that high-dose Yacon LWE lowers the blood glucose level partly by enhancing insulin sensitivity and hepatic glucose metabolism in type 2 diabetic mice.

• Journal of Life Science
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• v.27 no.1
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• pp.32-37
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• 2017

Cyanidin-3-O-glucoside (C3G) shows anti-inflammatory and antioxidant effects; however, its effect on postprandial blood glucose levels remains unknown. Alpha-glucosidase inhibitors regulate post-prandial hyperglycemia by impeding carbohydrate digestion in the small intestine. Here, the effect of C3G on ${\alpha}-glucosidase$ and ${\alpha}-amylase$ inhibition and its ability to ameliorate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice were evaluated. ICR normal and STZ-induced diabetic mice were orally administered soluble starch alone or with C3G or acarbose. The half-maximal inhibitory concentrations of C3G for ${\alpha}-glucosidase$ and ${\alpha}-amylase$ were 13.72 and $7.5{\mu}M$, respectively, suggesting that C3G was more effective than acarbose. The increase in postprandial blood glucose levels was more significantly reduced in the C3G groups than in the control group for both diabetic and normal mice. The area under the curve for the diabetic mice was significantly reduced following C3G administration. C3G may be a potent ${\alpha}-glucosidase$ inhibitor and may delay dietary carbohydrate absorption.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.759-767
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• 2014

This study examined the effect of Momordica charantia L. (bitter melon: BM) on lipid and hepatic antioxidative enzyme levels in diabetic rats. Diabetes mellitus was induced in male Sprague-Dawley rats by injection of streptozotocin (STZ), and rats were fed for 4 weeks with experimental groups divided into four groups: a normal control group, STZ-control and STZ-BM 5% & STZ-BM 10% treated groups. Levels of free fatty acids (FFA), high-density lipoprotein cholesterol (HDL-chol), triglycerides (TG) in plasma and malondialdehyde (MDA) & protein in liver, catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), and xanthine oxidase (XOD) were measured in liver cytosol. Level of HDL-chol significantly increased in the STZ-BM 5% diabetic group. TG & FFA levels were significantly higher in all diabetic groups compared to the control group. MDA and protein levels were significantly higher in the STZ-BM 5% group compared to all other experimental group. CAT level was higher in the supplementary group with BM compared to the STZ-control group, although the difference was not significantly different. SOD level was not significant in any experimental groups. GST level was significantly higher in the BM-treated groups compared to the STZ-control group. XOD level was significantly lower in the BM 5% group and significantly decreased in all experimental groups. These results show that supplementation of BM fruit powder may have beneficial effects on diabetic complications and damage caused by oxidative stress.

• Korean Journal of Food Science and Technology
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• v.54 no.1
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• pp.17-27
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• 2022

In this study, we evaluated the antioxidant and antidiabetic effects of buckwheat. The diabetic animal models were divided into four groups: normal mice group (NOR), streptozotocin-induced diabetic mice group (STZ), group treated with seeds of common or tartary buckwheat (SCB or STB), and the group treated with whole plants of common or tartary buckwheat (PCB or PTB). Rutin content was 44-48 times higher in STB or PTB than in SCB. Oral glucose tolerance and insulin resistance were significantly reduced by treatment with STB, PCB, and PTB. Treatment with PTB also decreased the serum glucose level significantly and the serum insulin levels slightly compared with the STZ group. These results suggest that rutin content and antioxidant activity are closely related to the antidiabetic effect of the treatment. Our results demonstrate that the seeds of tartary buckwheat and whole plants of either common or tartary buckwheat have antidiabetic effects-attenuating blood glucose in an animal model of type II diabetes.

• Biomolecules & Therapeutics
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• v.7 no.2
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• pp.178-184
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• 1999

Bamboo salt has been used for the purpose of precaution and treatment of certain diseases including cancer. Therefore, present study was carried out to ascertain the effects of bamboo salt upon anti-cancer, anti-hypertensive, and anti-diabetic activities as well. To examine the anti-cancer activity of bamboo salt, ICR mice implanted with 1$\times$l0$^{6}$ cells of sarcoma 180 intraperitoneally had been treated daily with bamboo salt A, crude salt, and reagent-grade NaCl (0.2, 1.0, and 2.0 g/kg, p.o.) for 60 days using adriamycin (2 mg/kg) as a positive control. Neither survival rate nor body weight had been significantly influenced by all the treatments indicating that bamboo salt A did not exert the anti-cancer effect on ICR mice. Anti-hypertensive activity was examined in spontaneously hypertensive rats (SHR) which had been administered with bamboo salt A, crude salt, and reagent-grade NaCl (0.1, 0.5, and 1.0% in drinking water) for 28 days using hydralazin (2 mg/kg) as a positive control. Blood pressure and heart rate were measured at 1, 3, and 4 weeks after the starting date. Significant anti-hypertensive activity was not observed in any treated group compared to the positive control group. In order to determine if bamboo salt had anti-diabetic activity, rats in which diabetes had been induced by streptozotocin (45 mg/kg, i.m.) were treated daily with bamboo salt A, crude salt, and reagent-grade NaCl (0.2, 1.0, and 2.0 g/kg, p.o.) for 28 days using insulin (50 U/kg, s.c..) as a positive control. Blood samples were taken and analyzed at 1,2, and 4 weeks after the starting date. Bamboo salt did not cause any decreasing effect on the blood glucose levels. These results clearly demonstrated that bamboo salt A did not exert anti-cancer, anti-hypertensive, or anti-diabetic activities in the present experimental animals.

• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.558-561
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• 2008

Culture broth of Bacillus subtilis Y3-7 in tryptic soy broth (TSB) isolated from Korean traditional fermented food was evaluated for the inhibition of $\alpha$-glucosidase. The results of in vitro studies using the yeast $\alpha$-glucosidase demonstrated that the culture broth exerted inhibitory effects on $\alpha$-glucosidase with $IC_{50}$ value of 1.62 mg/mL, and functioned as a competitive inhibitor. Furthermore, the culture broth of B. subtilis Y3-7 significantly improved glucose tolerance in normal and streptozotocin-induced diabetic mice. The blood glucose levels in the mice receiving sucrose supplementation in the culture broth (1 g/kg, 2 g/kg) were measured at 48.7%, which corresponded to 22.2% of the levels measured in the control mice. These results indicated that the culture broth of B. subtilis Y3-7 in TSB might be considered as a useful compound for the preparation of functional foods for diabetic patients.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.427-438
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• 2022

Pyroptosis, a form of cell death associated with inflammation, is known to be involved in diabetic nephropathy (DN), and discoid domain receptor 1 (DDR1), an inflammatory regulatory protein, is reported to be associated with diabetes. However, the mechanism underlying DDR1 regulation and pyroptosis in DN remains unknown. We aimed to investigate the effect of DDR1 on renal tubular epithelial cell pyroptosis and the mechanism underlying DN. In this study, we used high glucose (HG)-treated HK-2 cells and rats with a single intraperitoneal injection of streptozotocin as DN models. Subsequently, the expression of pyroptosis-related proteins (cleaved caspase-1, GSDMD-N, Interleukin-1β [IL-1β], and interleukin-18 [IL-18]), DDR1, phosphorylated NF-κB (p-NF-κB), and NLR family pyrin domain-containing 3 (NLRP3) inflammasomes were determined through Western blotting. IL-1β and IL-18 levels were determined using ELISA. The rate of pyroptosis was assessed by propidium iodide (PI) staining. The results revealed upregulated expression of pyroptosisrelated proteins and increased concentration of IL-1β and IL-18, accompanied by DDR1, p-NF-κB, and NLRP3 upregulation in DN rat kidney tissues and HG-treated HK-2 cells. Moreover, DDR1 knockdown in the background of HG treatment resulted in inhibited expression of pyroptosis-related proteins and attenuation of IL-1β and IL-18 production and PI-positive cell frequency via the NF-κB/NLRP3 pathway in HK-2 cells. However, NLRP3 overexpression reversed the effect of DDR1 knockdown on pyroptosis. In conclusion, we demonstrated that DDR1 may be associated with pyroptosis, and DDR1 knockdown inhibited HG-induced renal tubular epithelial cell pyroptosis. The NF-κB/NLRP3 pathway is probably involved in the underlying mechanism of these findings.

• Journal of Life Science
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• v.32 no.8
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• pp.589-594
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• 2022

The objective of this study was to investigate whether betulinic acid can inhibit the activities of carbohydrate-digesting enzymes and reduce postprandial hyperglycemia in mice with streptozotocin-induced diabetes. Our results revealed that betulinic acid has potent inhibitory effects on α-glucosidase and α-amylase activities. The half-maximal inhibitory concentrations (IC₅₀) of betulinic acid were 12.83±6.81 and 18.32±3.24 μM for α-glucosidase and α-amylase, respectively. This result indicates lower IC₅₀ values and higher inhibitory activities than those of acarbose, an oral hypoglycemic drug. The increase in postprandial blood glucose levels was significantly suppressed in the betulinic acid group than in the control group of diabetic and normal mice. Postprandial blood glucose levels were 23.22±1.1, 24.38±1.31, and 21.05±1.36 μM in the betulinic acid group compared to 24.64±1.7, 27.22±1.58, and 26.36±1.40 μM in the control group of diabetic mice at 30, 60 and 120 min, respectively. The area under the curve also significantly decreased with the administration of betulinic acid in diabetic mice, however, it did not decrease more than that after acarbose administration. Our results showed that betulinic acid may be a potent inhibitor of carbohydrate-digesting enzymes and ameliorate postprandial hyperglycemia in diabetic mice.

• Journal of Life Science
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• v.12 no.6
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• pp.661-668
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• 2002

We investigated the effect of tea fungus/kombucha beverage(TF) on the body weights, the blood glucose levels, lipid and protein concentrations, and enzyme activities in diabetic female rats. Sprague-Dawley rats were fed drinking water supplemented with 20% or 40% TF groups, respectively for 7 weeks. The female rats (mean weight 155.5$\pm$9.3 g) were assigned to one control and three diabetic groups. Diabetic groups were divided into diabetic control (TF free water), 20% or 40% TFD groups (20% or 40% TF in water) according to the levels of TF supplementation. Diabetes was experimentally induced by intraperitonially administration of streptozotocin in citrate buffer(pH 4.3) after 2 weeks feeding of four experimental water. Animals were sacrificed at the 5 weeks of diabetic state. The diabetic groups showed significantly decrease of body weight(6.8-7.5 g) compared with the control group(48.3 g). The hepatic, kidney and pancreatic weights of 20% or 40% TFD groups were not significantly different with D-control group. The fasting serum glucose level were higher in all diabetic groups than that of the control group. The concentrations of serum triglyceride in 40% TFD group and serum LDL-cholesterol in 20% TFD group were significantly decreased compared with the D-control group. The concentrations of serum total cholesterol and HDL-cholesterol, HDL-cholesterol/total cholesterol ratio, and atherogenic index in 20% or 40% TFD groups were similar to those in D-control group. The concentrations of hepatic triglyceride in 20% or 40% TFD groups were significantly decreased compared with the D-control group, but the concentrations of hepatic cholesterol and phospholipid were similar to all diabetic groups. The concentrations of serum and hepatic total protein, serum albumin, and the activities of GOT, GPT and LDH in the serum were the same levels of all diabetic groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.5
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• pp.682-688
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• 2011

The purpose of this study was to measure the blood glucose level and glycemic index (GI) in response to persimmon (Diospyros kaki Thunb) syrup extracted from persimmon and extract of persimmon by-products. Major component analyses of persimmon syrup I (PSI, 95:5 mixture of purified persimmon syrup and non-purified persimmon syrup) and persimmon syrup II (PSII, 50:50 mixture ratio of purified persimmon syrup and non-purified persimmon syrup) were $0.3{\pm}0.1$ and $0.6{\pm}0.2$ mg/g for total polyphenolic compounds and $70.6{\pm}0.6$ and $66.6{\pm}1.6%$ for total carbohydrates, respectively. Blood glucose responses of PSI and PSII were determined using both normal ICR mice and streptozotocin (STZ)-induced diabetic male Sprague-Dawley (SD) rats. Further, oral glucose tolerance test (OGTT) was performed on diabetic rats to assess the effects of the experimental diets. Blood glucose response and OGTT showed that blood glucose levels were significantly lower in mice and diabetic rats fed PSI and PSII compared to those fed diets of sugar, maple syrup, or honey. The GIs of healthy volunteers in response to PSI and PSII were calculated to be 51.9 and 35.7, respectively. On the contrary, the GIs of healthy volunteers fed diets including sugar, maple syrup, or honey were 52.6, 20.0, and 93.0, respectively. These results suggest that persimmon syrup can be used for both the treatment of diabetics and healthy people due to its beneficial effects on blood glucose level.