• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.21-27
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• 2012

Ground seawater in the east area of the volcanic Jeju Island contains abundant minerals. We investigated the metabolic activity of electrodialyzed, desalted ground seawater (EDSW) from Jeju in both cultured cells and animals. The addition of EDSW to the culture medium (up to 20%, v/v) reduced the leakage of lactate dehydrogenase and increased MTT activity in CHO-IR cells. EDSW (10%) promoted insulin-induced glucose consumption in L6 muscle cells as well as the activities of the liver ethanol-metabolizing enzymes, alcohol dehydrogenase and aldehyde dehydrogenase. Moreover, EDSW suppressed palmitate-induced intracellular fat accumulation in human hepatoma $HepG_2$ cells. Activities of AMP-stimulated protein kinase and acetyl CoA carboxylase, enzymes that modulate fat metabolism, were altered by EDSW in $HepG_2$ cells toward the suppression of intracellular lipid accumulation. EDSW also suppressed hepatic fat accumulation induced by a high-fat diet in mice. Taken together, EDSW showed beneficial metabolic effects, including the enhancement of ethanol metabolism and insulin-induced glucose consumption, and the suppression of intrahepatic fat accumulation.

• Molecules and Cells
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• v.40 no.2
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• pp.123-132
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• 2017

Insulin signaling is coordinated by insulin receptor substrates (IRSs). Many insulin responses, especially for blood glucose metabolism, are mediated primarily through Irs-1 and Irs-2. Irs-1 knockout mice show growth retardation and insulin signaling defects, which can be compensated by other IRSs in vivo; however, the underlying mechanism is not clear. Here, we presented an Irs-1 truncated mutated mouse ($Irs-1^{-/-}$) with growth retardation and subcutaneous adipocyte atrophy. $Irs-1^{-/-}$ mice exhibited mild insulin resistance, as demonstrated by the insulin tolerance test. Phosphatidylinositol 3-kinase (PI3K) activity and phosphorylated Protein Kinase B (PKB/AKT) expression were elevated in liver, skeletal muscle, and subcutaneous adipocytes in Irs-1 deficiency. In addition, the expression of IRS-2 and its phosphorylated version were clearly elevated in liver and skeletal muscle. With miRNA microarray analysis, we found miR-33 was down-regulated in bone marrow stromal cells (BMSCs) of $Irs-1^{-/-}$ mice, while its target gene Irs-2 was up-regulated in vitro studies. In addition, miR-33 was down-regulated in the presence of Irs-1 and which was up-regulated in fasting status. What's more, miR-33 restored its expression in re-feeding status. Meanwhile, miR-33 levels decreased and Irs-2 levels increased in liver, skeletal muscle, and subcutaneous adipocytes of $Irs-1^{-/-}$ mice. In primary cultured liver cells transfected with an miR-33 inhibitor, the expression of IRS-2, PI3K, and phosphorylated-AKT (p-AKT) increased while the opposite results were observed in the presence of an miR-33 mimic. Therefore, decreased miR-33 levels can up-regulate IRS-2 expression, which appears to compensate for the defects of the insulin signaling pathway in Irs-1 deficient mice.

• Food Science and Preservation
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• v.18 no.6
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• pp.923-929
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• 2011

For the purpose of investigating the in vitro antidiabetic activity of a medicinal herb mixture prepared through traditional antidiabetic prescription, the study analyzed the existence of insulin-similar components and examined ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibition activity. As a result of arranging the medicinal herb mixture extracts over the 3T3-L1 fibroblast in the concentration of $10{\mu}g/mL$, which confirmed that it included much of insulin sensitizer components as 151.7% in the differentiation of 3T3-L1 fibroblast. The inhibition activity against ${\alpha}$-amylase of the medicinal herb mixture extracts as hypoglycemic agent were 38.4, 31.5 and 16.6% in the concentration of 10.0, 1.0 and 0.1 mg/mL, respectively. The inhibition activity against ${\alpha}$-glucosidase of the medicinal herb mixture extracts were 81.3, 35.8 and 26.7% in the concentration of 10.0, 1.0 and 0.1 mg/mL, respectively. The inhibition activity against ${\alpha}$-glucosidase in the ethyl acetate fractions of the water and 80% ethanol extracts were 66.9% and 55.1%, respectively, the highest levels in the various solvent extracts.

• Korean Journal of Pharmacognosy
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• v.32 no.4 s.127
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• pp.327-329
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• 2001

Cordyceps militaris (CM) has been used as a tonics in the traditional medicine. To investigate the anti-diabetic principle of CM, activity guided fractionation was conducted. Hot water extract of CM was fractionated into 3 parts: above 100,000(A), $100,000{\sim}20,000(B)$, below 20,000(C) in molecular weight using in membrane filter system. All fractions showed mild hypoglycemic activity in streptozotocin (STZ)-induced diabetic rats by oral administration (300 mg/kg). The fraction C which was most active among them was fractionated again into two parts, C-1 and C-2 by Sephadex LH 20 column chromatography. The fraction C-1 showed hypoglycemic activity but C-2 did not show activity compared with control in STZ mice. In glucose-fed hyperglycemic mice, fraction C, C-1 and C-2 also showed significant glucose lowering activity. Their decreasing rates of plasma glucose level after 1 hours administrations of fraction C, C-1 and C-2 were 24.5%, 29.3% and 22.0%, respectively (Tolbutamide: 48.4%). These results suggested that CM has both insulin like and insulin release promoting activity and could be developed as an antidiabetic agent.

• Nutritional Sciences
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• v.3 no.2
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• pp.57-65
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• 2000

Partial enteral nutrition (PEN) supplemented with insulin-like growth factor-I (IGF-I) to neonatal piglets receiving parenteral nutrition increases lactase-phlorizin hydrolase (LPH) activity, but not LPH mRNA. The goal of the current study was to investigate the mechanism by which IGF-I up-regulates LPH activity. We hypothesized that IGF-I regulates LPH synthesis post-transcriptionally. Methods: Newborn piglets (n=15) received 100% parenteral nutrition (TPN), 80% parenteral nutrition + 20% PEN (PEN), or PEN + IGF-I (1.0mg/kg/d). On day 7, two stable isotopes of leucine, [$^2 H_3$]-leucine and [$^{13}C_1$]-L-leucine were intravenously administered to measure mucosal protein and brush LPH (BB LPH) synthesis. Results: Weight gain, nutrient intake and jejunal weight and length were similar among the treatment groups. PEN increased mucosal weight, villus width and cross-sectional area, LPH activity, mRNA expression and the abundance of proLPHh compared to 100% TPN (p<0.05). IGF-I further increased mucosal weight, LPH activity and LPH activity per unit BB LPH ~2-fold over PEN alone (p<0.05), but did not affect LPH mRNA or the abundance of proLPHh or mature LPH. Isotopic enrichment of [$^2 H_3$]-leucine and [$^{13}C_1$]-L-leucine in plasma, mucosal protein and LPH precursors, and the fractional and absolute synthesis rates of mucosal protein and LPH were similar among the treatment groups. Total mucosal protein synthesis was increased 60% (p<0.05) and LPH synthesis tended (p=0.14) to be greater in the IGF-I treated animals compared to the other two groups. Conclusions: The primary mechanism by which IGF-I up-regulates LPH may be post-translational, either via reducing LPH turnover, or by specifically altering LPH activity.

• Korean Journal of Pharmacognosy
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• v.44 no.1
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• pp.75-82
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• 2013

Previous studies have shown that Aloe QDM complex, which is consisted of chromium (Cr), aloesin (ALS) and processed Aloe vera gel (PAG), exert antidiabetic activity in a high fat diet-induced mouse model of type 2 diabetes. In this study we examined the mechanism of the antidiabetic activity of the Aloe QDM complex. Rat myoblast cell line L6 cells were cultured in the presence of Cr, ALS, and PAG alone and in combinations, and then the capability of the cells to uptake glucose was examined using radiolabeled glucose. All of the 3 agents, Cr, ALS and PAG, exerted glucose uptake-enhancing activity in L6 cells. The most potent capability to uptake glucose was observed when L6 cells were cultured with the Aloe QDM complex. The activity of the Aloe QDM complex to enhance glucose uptake was prominent in conditions where existing insulin concentrations are low. We also examined the effects of the Aloe QDM complex on the plasma membrane expression of GLUT4 in L6 cells. The Aloe QDM complex increased the content of GLUT4 in the plasma membrane, while decreasing the content of GLUT4 in the light microsome. Taken together, these results show that the antidiabetic activity of the Aloe QDM complex is at least in part due to the stimulation of glucose uptake into the muscle cells, and this activity of the Aloe QDM complex is mediated through the enhancement of the translocation of GLUT4 into the plasma membrane.

• The Korean Journal of Zoology
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• v.31 no.3
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• pp.185-190
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• 1988

To investigate whether malignant behavior of skin tumor correlates with changes in the level of proteolytic activities in skin tumors, rats were treated with 7,12-dimethylbenzanthracene followed by photbor ester. Tumors induced upon the treatrnents exhibited more than 20-fold increase in the activity of plasminogen activator and about 3-fold of plasmin-like activity. as compared to those in treated controls. Furthermore, the former activity was raised to about 6-fold even in the preneoplastic dssues of the skin tissues. On the other hand, the proteolytic activity against casein and insulin decreased to several-fold in the tumor tissues while antitrvpsin activity remained similar in both tumor and controls. Thus, the increase in the activities of plasmInogen activator and plasminlike enzyme appears to occur as a charaderistic to skin cancer and may involve in invasion and metsstasis of the tumor.

• Nutritional Sciences
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• v.6 no.4
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• pp.195-200
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• 2003

In recent years, the prevalence of type 2 diabetes mellitus has dramatically increased in Korea as the diet has rapidly become westernized. We determined the effect of long-term cola intakes on glucose metabolism and oxidative stress in weanling male Sprague Dawley rats consuming a moderate fat diet Thirty male rats, born from 6 female rats, were randomized into cola or water drinking groups. For 28 weeks, all rats were provided with an ad lib solid diet having 33 percent of its metabolisable energy as fat In addition, rats of the cola group were provided with ad lib cola instead of water. The daily total caloric intake did not differ between groups. The rats in the cola group consumed a higher proportion of carbohydrates, and their mean body weight and fasting serum insulin level were lower than that of the control group. Whole-body glucose disposal rates measured by an euglycemic hyperinsulinemic clamp were higher in the cola group. However, lipid peroxide levels in kidney tissue were higher in the cola group than in the control group. Superoxide dismutase activity in kidney tissues was lower in the cola group compared to the control group, while glutathion peroxidase and catalase activities were not significantly different between the two groups. In conclusion, long-term cola intakes decreased insulin resistance, but increased oxidative stress in kidney tissue due to decreased SOD activities, which may lead to kidney damage. Thus, moderate changes in insulin resistance may not affect the status of oxidative stress, and vice versa.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.707-713
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• 2012

Taraxacum coreanum Nakai (TM) has been investigated for its antidiabetic activity in streptozotocin induced diabetic animals, but few studies have been conducted to evaluate its efficacy for treatment of type II diabetic mice. This study was designed to evaluate the efficacy of the water extracts of TM for the treatment of type II diabetes. Twenty four mice(C57BLKS/J Iar $-+Lepr^{db}/+Lepr^{db}$) with type II diabetes were randomly assigned either to a experimental group A (leaves extraction of TM), experimental group B(roots extraction of TM), experimental group C(leaves, roots and flowers extraction of TM) or control group. Water extracts of TM were ingested for 10 weeks. The changes of body weight, level of blood glucose, numerical change of insulin-immunoreactive cells and level of blood insulin were measured after treatment of water extracts of TM. A reduction of the blood glucose level after treatment of TM was observed in all the experimental groups. Especially, experimental C group showed significant reduction of blood glucose level compared with control group. Experimental C group induced an increase the level of blood insulin and density of insulin immunoreactive cells after treatment of TM. These results show that water extracts of TM can improve the severity in type II diabetic mice.

• Nutrition Research and Practice
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• v.7 no.6
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• pp.446-452
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• 2013

Chronic consumption of a high-fat, high-sucrose (HFHS) diet increases insulin resistance and results in type 2 diabetes mellitus in C57BL/6J mice. Hyperglycemia in diabetics increases oxidative stress, which is associated with a high risk of diabetic complications. The purpose of this study was to examine the hypoglycemic and antioxidant effects of chamnamul [Pimpinella brachycarpa (Kom.) Nakai] in an animal model of type 2 diabetes. The ${\alpha}$-glucosidase inhibitory activity of a 70% ethanol extract of chamnamul was measured in vitro. Five-week-old male C57BL/6J mice were fed a basal or HFHS diet with or without a 70% ethanol extract of chamnamul at a 0.5% level of the diet for 12 weeks after 1 week of adaptation. After sacrifice, serum glucose, insulin, adiponectin, and lipid profiles, and lipid peroxidation of the liver were determined. Homeostasis model assessment for insulin resistance (HOMA-IR) was determined. Chamnamul extract inhibited ${\alpha}$-glucosidase by 26.7%, which was 78.3% the strength of inhibition by acarbose at a concentration of 0.5 mg/mL. Serum glucose, insulin, and cholesterol levels, as well as HOMA-IR values, were significantly lower in the chamnamul group than in the HFHS group. Chamnamul extract significantly decreased the level of thiobarbituric acid reactive substances and increased the activities of superoxide dismutase, catalase, and glutathione peroxidase in the liver compared with the HFHS group. These findings suggest that chamnamul may be useful in prevention of hyperglycemia and reduction of oxidative stress in mice fed a HFHS diet.