• YAKHAK HOEJI
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• v.43 no.6
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• pp.818-826
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• 1999

Antidiabetic activity and mechanism of Sangbackpitang (SBPT) was examined in db/db mice, which is a spontaneously hyperglycemic, hyperinsulinemic and obese animal model. SBPT and acarbose were administered orally for 4 weeks. Fasting and non-fasting serum glucose, glycated hemoglobin and triglyceride were all reduced when compared between db/db control group and SBPT treated group. At 12th week after birth, SBPT increased an insulin secretion although statistic significance was not seen. Total activities of sucrase, maltase and lactase in SBPT treated group were all decreased when compared to db/db control. On the other hand, sucrase and maltase activities in acarbose treated groups were increased. Effect of SBPT on mRNA expression of glucose transporter(GLUT-4) was also examined. Quantitation of glucose transporter was performed by RT-PCR and in vitro transcription with co-amplification of rat-action gene as an internal standard. Muscular GLUT-4 mRNA expression in SBPT treated group was increased significantly. These results may suggest that SBPT lowered blood glucose ascribing to inhibition of glycosidase-catalyzed reaction and upregulation of muscular GLUT-4 mRNA expression.

• Preventive Nutrition and Food Science
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• v.2 no.2
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• pp.149-154
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• 1997

The ability of exercise and buckwheat diet to modify plasma glucose and cholesterol levels in streptozotocin-induced diabetic rats has been studied. Diabetic rats were fed corn starch as a control diet or buckwheat as an experimental diet for 4 weeks. One group of rats were exercise-trained to swim for 60 min/day, 6 days a week. Plasma glucose levels of sedentary rats both on the control diet and on the buckwheat diet were significantly increased from 367.0$\pm$33.6 mg/dl to 545.0$\pm$38.7 mg/dl and from 380.3$\pm$18.9 mg/dl to 540.5$\pm$36.6 mg/dl, respectively. However, this large increase of plasma glucose was not seen in exercised rats on the buckwheat diet (from 345.0$\pm$25.6 mg/dl to 391.4$\pm$34.7 mg/dl). The total plasma cholesterol level was not affected by either diet or exercise. The HDL-cholesterol level tends to increase due to the buckwheat diet or an exercise, but not with a significant increase. Our results suggest that the buckwheat diet is beneficial in lowering the plasma glucose level only when diabetic rats ar exercised.

• Nutritional Sciences
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• v.6 no.4
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• pp.201-208
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• 2003

This research was conducted to study the effects of the supplementation of multi-extracts of mori folium (MF) and of exercise on plasma insulin and glucose levels in streptozotocin (STZ)-induced diabetic rats. Eight male Sprague-Dawley rats, 4 weeks old, were assigned to each experimental group and were raised in the laboratory for 10 weeks. The animal groups consisted of a normal-control group, a STZ-control group, 3 STZ-induced diabetic groups supplemented ad libitum with various amounts of MF extracts (MF-720, MF-360, and MF-180 groups), and a STZ-induced diabetic group supplemented with MF-360 along with exercise. In the normal-control group, glucose tolerance tests resulted in the peak blood glucose level being achieved in 15 minutes and a fasting blood glucose level being achieved in 60 minutes. In the STZ-control group, the peak blood glucose level was reached after 60 minutes and, even after 90 minutes, blood glucose shown at a significantly higher level compared to the fasting levels. In the groups supplemented with MF extracts, the blood glucose level peaked after 30 minutes of glucose challenge, and returned to the fasting level after 90 minutes; the MF-360 and MF-360+exercise groups showed the best levels of glucose tolerance. Blood glucose levels in the STZ-induced diabetic groups were significantly higher compared to the normal-control group. However, after 7 weeks of supplementation with MF extracts, a significant lowering of blood glucose levels was observed in all groups supplemented with the MF extract. The best effect was observed in the group given MF extract combined with exercise. Compared to the normal-control group, blood insulin levels were significantly lower in all STZ-induced diabetic groups; however, a significantly higher level of insulin was observed in the groups given MF extracts compared to the STZ-control group. This study shows that the supplementation of MF extracts in STZ-induced diabetic rats resulted in increased blood insulin levels and lower blood glucose levels.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.391-395
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• 1997

It was proved that both ethanol extracts from Mori Folium from Kangwon do and silk worm had higher inhibition acitivity on $\alpha$-glucohydrolase than the water extracts. In adding above 8.5 (mg/L) of silkworm extracts, the inhibition rate on $\alpha$-1,4 glucosidase was saturated while the inhibition rate was continuously increased in adding the extracts from Moli Folium. It was also found that the diethyl ether fraction showed much better inhibition activity than water fraction from ethanol extracts, yielding ca. 85% of inhibition rate for the extract of Moli Folium, compared to 91% for a commercially available hypoglycemic drug, Chloropropamide. In separating the diethyl ether fractions by Consecutive Sephadex gel filtration and Thin layer chromatography, three and four active spots were obtained from Moli Folium and silkworm, respectively. It is interesting that the similar Rf spots from both species among several spots in TLC have the highest inhibition acitivity on a target enzyme, which can imply that the active substances from both species are same or similar molecular weight and structure. Glucose-lowering activities of both speciese were also examined in vivo, showing that the fraction from Moli Folium had better activity than that from silkworm, and its activity was similar to that of a commercial drug.

• Biomedical Science Letters
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• v.11 no.4
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• pp.487-492
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• 2005

The baculovirus/insect cell expression system is of great value in the study of structure-function relationships in mammalian glucose-transport proteins by site-directed mutagenesis and for the large-scale production of these proteins for mechanistic and biochemical studies. Spodoptera frugiperda Clone 21 (Sf2l) cells grow well on TC-100 medium that contains $0.1\%$ D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transporters. However, very little is known about the properties of the endogenous sugar transporter(s) in Sf2l cells, although a saturable transport system for hexose uptake has been previously revealed in the Sf cells. In order to further examine the substrate and inhibitor recognition properties of the Sf2l cell transporter, the ability of hexoses to inhibit 2-deoxy-D-glucose (2dGlc) transport was investigated by measuring inhibition constants $(K_i)$. The $K_i's$ for reversible inhibitors were determined from plots of uptake versus inhibitor concentration. Transport was effectively inhibited by D-mannose and D-glucose. Of the hexoses tested, L-glucose had the least effect on 2dGlc transport in the Sf2l cells, indicating that the transport is stereoselective. Unlike the human HepG2 type glucose transport system, D-mannose had a somewhat greater affinity for the Sf2l cell transporter than D-glucose, implying that the hydroxyl group at the C-2 position is not necessary for strong binding. However, epimerization at the C-4 position of D-glucose (D-galactose) resulted in a dramatic decrease in affinity of the hexose for the Sf2l cell transporter. Such a lowering of affinity might be the result of the involvement of the C-4 hydroxyl in hydrogen bonding. It is therefore suggested that Sf2l cells were found to contain an endogenous sugar transport activity that in several aspects resembles the human HepG2 type glucose transporter, although the insect and human transporters do differ in their affinity for cytochalasin B.

• Molecules and Cells
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• v.44 no.2
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• pp.68-78
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• 2021

Secondary metabolites enable plants to protect themselves from herbivorous insects. Among these, cucurbitacin B (cuc-B) is a bitter-tasting compound with promising pharmacological potential. Dietary exposure to cuc-B lowered the hemolymph glucose levels of Drosophila melanogaster fed with a high carbohydrate diet, which is homologous to high blood glucose in humans, and its effect was comparable to that of metformin, a well-known glucose-lowering drug. Furthermore, cuc-B reduced tissue sugar levels and glycogen levels, as well as triacylglycerol levels. Our results thus highlight the potential applicability of this compound to treat chronic metabolic diseases such as diabetes and obesity. Additionally, we analyzed sleep quality and taste-associative memory enhancement after cuc-B and metformin treatment. Both supplements increased nighttime bout length and metformin increased memory consolidation. Therefore, discarded shell of Cucurbitaceae could be processed into health supplements.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.637-643
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• 2013

We have demonstrated that 1-deoxynojirimycin (DNJ) isolated from Bacillus subtilis MORI could enhance the levels of adiponectin and its receptors in differentiated 3T3-L1 adipocytes, which has been shown to be effective in lowering blood glucose levels and enhancing insulin sensitivity. DNJ was not toxic to differentiated 3T3-L1 adipocytes for up to a concentration of $5{\mu}M$. In terms of expression levels of adiponectin and its receptors (AdipoR1 and AdipoR2), DNJ in concentrations as low as $0.5{\mu}M$ elevated both mRNA and protein levels of adiponectin and transcript levels of AdipoR1 and AdipoR2. In addition, DNJ increased phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK) in a statistically significant manner. Finally, treatment with DNJ resulted in increased mRNA expression of glucose transporter 4 (GLUT4), which encodes for a glucose transporter, along with a significant increase in glucose uptake into the adipocytes based on results of a 2-deoxy-D-[$^3H$] glucose uptake assay. Our findings indicate that DNJ may greatly facilitate glucose uptake into adipose tissues by increasing the action of adiponectin via its up-regulated expression as well as its receptor genes. In addition, the glucose-lowering effects of DNJ may be achieved by an increased abundance of GLUT4 protein in the plasma membrane, as a consequence of the increased transcript levels of the GLUT4 gene and the activation of AMPK.

• Korean journal of food and cookery science
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• v.11 no.3
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• pp.267-273
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• 1995

Twenty five cooking recipe with yam (Dioscorea japonica Thunb) have been developed and their hypoglycemic effects on diabetic patients were investigated. The results of the sensory evaluations revealed that the tested recipe were in good scores (overall acceptability scores 3.30-4.33) except Chojuli. The 10-panel members indicated that the yam cookings were more acceptable when they were cooked with other vegetables. Twenty seven diabetic patients were entered in a general hospital during the 2-month experimental period and they were allowed to consume the diet with yam cooking dish, 75 g of yam a day. The fasting blood glucose and 2-hour postprandial blood glucose levels were determined. The diabetic patients who consumed yam showed the lower blood glucose levels than those patients who were controlled with the hospital diet only. The hypoglycemic effects of the yam were more evident in the patients who were injected with insulin. The constant lowering effects of blood glucose levels were observed in the normal subjects who had taken the yam cookery, leading to that one subject who started with a low blood glucose level must stop the yam consumption after 10 days.

• Journal of Nutrition and Health
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• v.32 no.3
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• pp.230-238
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• 1999

The present study was conducted to investigate te effect of sea tangle and hypoglycemic agent(Metformin) on lipid peroxidation and antioxidants levels in normal and diabetic rats. Male Sprague-Dawley rats were fed AIN-76 based experimental diets containing 5% (w/w) cellulose or 15%(w/w) sea tangle for 3 weeks, and then rats of diabetic groups were rendered diabetic by intramuscular injection of streptozotocin(STZ, 45mg/kg BW). After induction of diabetes Metformin(350mg/kg BW) was given once a day using a feeding tube for 5 days. Blood glucose level in diabetic rats fed sea tangle was significantly lower than that of diabetic rats fed cellulose. Metformin feeding resulted in further lowering blood glucose. Plasma and liver microsomal levels of lipid peroxides were increased significantly in diabetic rats as compared to normal rats, and the plasma level tended to be decreased by sea tangle feeding. Plasma level of retinol was reduced by STZ treatment, but it was increased by Metformin feeding in diabetic rats fed sea tangle. The liver contents of retinyl plamitate were reduced in diabetic rats but recovered by sea tangle feeding to some extent. Liver contents of total vitamin A were increased significantly by sea tangle in diabetic rats. Although difference in either plasma or liver level of $\alpha$-tocopherol by diet and STZ treatment was not significant, $\alpha$-tocopherol levels were the highest in the group with simultaneous feeding of sea tangle and metformin. Liver contents of zinc and copper were not influenced by either STZ treatment or sea tangle feeding. The present study indicates that the lowering blood glucose level could be attained by simultaneous trial of sea tangle diet and hypoglycemic agent and the increased oxidative stress caused by STZz treatment could be relieved by sea tangle feeding.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.277-281
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• 2013

Silkworm powder, which contains 1-deoxynojirimycin (DNJ), is a promising complementary and alternative medicine (CAM) in Korea. Silkworm powder was produced from Yeonnokjam pupae at d 3 of the 5th instar at the National Academy of Agricultural Science. The powder was derivatized with 9-fluorenylmethyl chloroformate (FMOC-Cl), and the DNJ-FMOC content was measured by HPLC. We investigated the content of 1-DNJ in the silkworm powder and its glucose-lowering effect when it was treated at different temperatures. The content of 1-DNJ was the lowest at $150^{\circ}C$, while it was constant at other temperatures. The silkworm extract powder was orally administered to diabetic mice (20 mg/kg/d) for 4 wk. Water intake did not significantly change when compared with the control group (T0). The blood glucose levels significantly decreased when mice where administered silkworm powder treated at $60^{\circ}C$ (T60) compared to the control group, but no difference was observed between the groups T100 and T150. Moreover, the blood levels of TG significantly decreased compared with the control group. Based on these results, we surmise that the properties of the silkworm extract powder were stable upon heating at $100^{\circ}C$ but not at $150^{\circ}C$.