• BMB Reports
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• 제38권2호
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• pp.211-217
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• 2005

Cordyceps, an entomopathogenic fungus, contains many health-promoting ingredients. Recent reports indicate that the consumption of cordyceps helps reduce blood-sugar content in diabetics. However, the mechanism underlying this reduction in circulatory sugar content is not fully understood. Methanolic extracts were prepared from the fruiting bodies of Paecilomyces tenuipes, and 4-beta acetoxyscirpendiol (4-ASD) was eventually isolated and purified. $Na^+$/Glucose transporter-1 (SGLT-1) was expressed in Xenopus oocytes, and the effect of 4-ASD on SGLT-1 was analyzed utilizing a voltage clamp and by performing 2-deoxy-D-glucose (2-DOG) uptake studies. 4-ASD was shown to significantly inhibit SGLT-1 activity compared to the non-treated control in a dose-dependent manner. In the presence of the derivatives of 4-ASD (diacetoxyscirpenol or 15-acetoxyscirpendiol), SGLT-1 activity was greatly inhibited in an 4-ASD-like manner. Of these derivatives, 15-acetoxyscirepenol inhibited SGLT-1 as well as 4-ASD, whereas diacetoxyscirpenol was slightly less effective. Taken together, these results strongly indicate that 4-ASD in P. tenuipes may lower blood sugar levels in the circulatory system. We conclude that 4-ASD and its derivatives are effective SGLT-1 inhibitors.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.710-716
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• 2016

Gamma-aminobutyric acid (GABA) is a non-protein amino acid, which is an important inhibitor of neurotransmission in the human brain. GABA is also used as the precursor of biopolymer Nylon-4 production. In this study, the carbon flux from the tricarboxylic acid cycle was directed to the GABA shunt pathway for the production of GABA from glucose. The GABA shunt enzymes succinate-semialdehyde dehydrogenase (GabD) and GABA aminotransferase (GabT) were co-localized along with the GABA transporter (GadC) by using a synthetic scaffold complex. The co-localized enzyme scaffold complex produced 0.71 g/l of GABA from 10 g/l of glucose. Inactivation of competing metabolic pathways in mutant E. coli strains XBM1 and XBM6 increased GABA production 13% to reach 0.80 g/l GABA by the enzymes co-localized and expressed in the mutant strains. The recombinant E. coli system developed in this study demonstrated the possibility of the pathway of the GABA shunt as a novel GABA production pathway.

• The Korea Journal of Herbology
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• 제31권1호
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• pp.1-5
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• 2016

Objectives : The purpose of this study was to investigate inhibitory effects of steamed Polygonatum odoratum extract (POE) on insulin resistance in rat skeletal muscle cells, L6 cells.Methods : Polygonatum odoratum (P. odoratum) extract was extracted with ethyl acetate. Activity of α-glucosidase in POE was measured for blood glucose regulation. MTT assay was examined for cell toxicity. Western blot analysis for measurement of adiponectine, peroxisome proliferator-activated receptorγ (PPARγ), insulin receptor substrate (IRS), glucose transporter 4 (Glut-4) and phosphorylation of serine/threonine-specific protein kinase (Akt) expressions were performed. Akt signaling pathway were analyzed with LY294002, which is a specific PI3K/Akt inhibitor.Results : The results revealed that POE inhibited α-glucosidase activity. Treatment of POE in L6 cells inhibited the differentiation of L6 cells compared to those of vehicl control. Additionally, protein expressions of adiponectine, PPARγ, IRS and Glut-4 were significantly regulated compared to those of vehicle control (p < 0.05), respectively. Futhermore, phosphorylation of Akt was increased in L6 cells treated with POE compared to that of vehicle control (p < 0.05). pAkt expression was significantly accentuated with Akt inhibitor (LY294002).Conclusions : These results suggest that POE may have potential as a natural agent for prevention/improvement of diabetes, especially, regulation of blood glucose. Therefore, further additional study should be conducted to elucidate in depth the pharmaceutical efficacy of these.

• Asian-Australasian Journal of Animal Sciences
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• 제24권12호
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• pp.1674-1680
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• 2011

This study was conducted to examine the effects of glucose, chromium picolinate (CrP), and vitamin C (Vit C) on lipid metabolism in Korean native steers fitted with indwelling catheters. A total of 12 Korean native steers were randomly allocated to the following treatments: 1) normal control diet, 2) same as 1) +250 g of glucose by intravenous (IV) infusion, 3) same as 2)+13.5 g CrP administered orally, and 4) same as 3)+2.52 g Vit C by IV infusion. Glucose, Vit C, and CrP treatments were administered for five days. At days 1 and 3, serum insulin was higher in treated animals than in those fed the control diet (p<0.05). Serum non-esterified fatty acid (NEFA) concentration in the steers on treatment 2), control+13.5 g CrP, was lower than those on other treatments at 90 min post-infusion on days 1 and 3 (p<0.05). The expression of peroxisome proliferator-activated receptor-${\gamma}$ (PPAR${\gamma}$)2, stearoyl-CoA desaturase-1 (SCD), fatty acid synthase (FAS), and glucose transporter type 4 (Glut 4) in the longissimus muscle of steers on treatment 2 was higher than those on other treatments. In conclusion, the results suggest that CrP is associated with the regulation of gene expression involved in adipogenesis.

• YAKHAK HOEJI
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• 제55권4호
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• pp.301-308
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• 2011

Diabetes has been one of major health risks in industrialized countries. AMP-activated protein kinase (AMPK) has been focused as a novel therapeutic target for the treatment of metabolic syndromes, because AMPK increases glucose uptake through independent insulin signal pathway. In this study, we investigated the anti-diabetic effect of Angelica gigas Nakai extract (AGNEX), a mixture of decursin and decursinol angelate (53 : 47), decursin and decursinol angelate on blood glucose, glucose transport (GLUT) and AMPK expression levels in streptozotocin (STZ)-induced diabetic rats. To induce diabetes, 50 mg/kg of STZ was injected via i.v. route and AGNEX 2 mg/kg (STZ+AG), decursin 2 mg/kg (STZ+D), decursinol angelate 2 mg/kg (STZ+DA), and metformin 100 mg/kg (STZ+M) were administered orally for 21 days. STZ+DA group showed a significant decrease in fasting blood glucose levels compared to the other groups. Decursinol angelate significantly upregulated expression of glucose transporter 4 (GLUT4) and phosphorylation of AMPK (p-AMPK) in skeletal muscle of rats. In pancreas of rats, decursinol angelate significantly increased expression of GLUT2 through down-regulation of p-AMPK. In addition to the result of pancreatic islets morphology, AGNEX, decursin, decursinol angelate, and metformin treated group recovered ${\beta}$-cell damage by hyperglycemia. These results indicate that decursinol angelate might be a potential anti-diabetic agent and AGNEX could be useful in the treatment of diabetes mellitus.

• Journal of the Korean Society of Food Culture
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• 제24권2호
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• pp.219-223
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• 2009

We investigated the effect of Takju lees extract on blood glucose levels in the db/db mice (a murine model of type 2 diabetes mellitus). We fed 40 male db/db mice a control diet (G0, AIN93G) and experimental diets containing 1% (G1), 2% (G2), or 4% (G4) Takju lees extract for 4 weeks. We found no difference in food intake and body weight gain among the animal groups. In the G1 and G2 groups, plasma glucose levels decreased significantly between Days 10 and 21 compared with the G0 group. However, we found no difference in plasma glucose levels between groups G4 and G0. The change in insulin concentrations was not significant among these animal groups, and we found no significant difference in glucose transporter 4 (GLUT4) expression in the soleus muscle. These results suggest that the Takju lees extract has a beneficial effect in animals with type 2 diabetes.

• Journal of Microbiology and Biotechnology
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• 제33권12호
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• pp.1563-1575
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• 2023

Acyl-coenzyme A (CoA):diacylglycerol acyltransferase 2 (DGAT2) catalyzes the last stage of triacylglycerol (TAG) synthesis, a process that forms ester bonds with diacylglycerols (DAG) and fatty acyl-CoA substrates. The enzymatic role of Dgat2 has been studied in various biological species. Still, the full description of how Dgat2 channels fatty acids in skeletal myocytes and the consequence thereof in glucose uptake have yet to be well established. Therefore, this study explored the mediating role of Dgat2 in glucose uptake and fatty acid partitioning under short interfering ribonucleic acid (siRNA)-mediated Dgat2 knockdown conditions. Cells transfected with Dgat2 siRNA downregulated glucose transporter type 4 (Glut4) messenger RNA (mRNA) expression and decreased the cellular uptake of [1-¹⁴C]-labeled 2-deoxyglucose up to 24.3% (p < 0.05). Suppression of Dgat2 deteriorated insulin-induced Akt phosphorylation. Dgat2 siRNA reduced [1-¹⁴C]-labeled oleic acid incorporation into TAG, but increased the level of [1-¹⁴C]-labeled free fatty acids at 3 h after initial fatty acid loading. In an experiment of chasing radioisotope-labeled fatty acids, Dgat2 suppression augmented the level of cellular free fatty acids. It decreased the level of re-esterification of free fatty acids to TAG by 67.6% during the chase period, and the remaining pulses of phospholipids and cholesteryl esters were decreased by 34.5% and 61%, respectively. Incorporating labeled fatty acids into beta-oxidation products increased in Dgat2 siRNA transfected cells without gene expression involving fatty acid oxidation. These results indicate that Dgat2 has regulatory function in glucose uptake, possibly through the reaction of TAG with endogenously released or recycled fatty acids.

• Journal of Ginseng Research
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• 제41권4호
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• pp.615-619
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• 2017

Background: Black ginseng has a more potent biological activity than non-steamed ginseng. We investigated the effects of long-term intake of dietary black ginseng extract (BG) on antioxidant activity in aged mice. We also compared the effects of BG on cognitive deficits with those of white ginseng extract (WG) and red ginseng extract (RG). Methods: Ten-month-old mice were fed an AIN-93G-based diet containing 10 g/kg (low dose, L) or 30 g/kg (high dose, H) WG powder, RG powder, or BG powder for 24 wk. We measured serum lipids, the activities of antioxidant enzymes, and malondialdehyde levels. Additionally, the protein expression levels of choline acetyltransferase and vesicular acetylcholine transporter, which are presynaptic cholinergic markers in the cortex and hippocampus of the brain, were measured by western blotting. Results: Triglyceride levels were reduced in all the extract-treated mice, except those in the LBG group. High-density lipoprotein cholesterol levels in the HBG group were higher than those in the control group. Total cholesterol levels were reduced in the LBG group. Additionally, glucose levels in the HBG group were significantly reduced by 41.2%. There were lower levels of malondialdehyde in the LBG group than in the control group. Furthermore, glutathione reductase activity increased in the HWG group and the HRG group. The protein expression levels of choline acetyltransferase and vesicular acetylcholine transporter significantly increased in all the ginseng-treated groups. Conclusion: The results suggest that supplementation with the tested ginseng extracts may suppress the cognitive decline associated with aging, via regulation of the cholinergic and antioxidant defense systems.

• Korean Journal of Clinical Pharmacy
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• 제27권4호
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• pp.214-220
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• 2017

Background: Dapagliflozin is an oral selective inhibitor of sodium-glucose cotransporter 2(SGLT2), the kidney transporter chiefly responsible for glucose reabsorption from the glomerular filtrate. Because this mechanism does not require the action of insulin, dapagliflozin rarely causes hypoglycemia. Dapagliflozin may affect blood glucose control as well as blood pressure and the body weight which are one of the cardiovascular disease risk factors. However, dehydration and ketoacidosis are reported as the side effects of the dapagliflozin treatment and the safety issues have been occurred. The aim of this study is to analyze the effectiveness and adverse events of dapagliflozin in Korean patients. Methods: From December 2014 to August 2015, we retrospectively reviewed the electronic medical records of type 2 diabetes patients who were prescribed dapagliflozin at Severance Hospital. Results: A total of 202 Korean patients were enrolled in this study. The effectiveness in the reduction of blood glucose was statistically significant(p<0.001). Dapagliflozin decreased 0.74% of HbA1c after 24 weeks. Significantly more participants achieved the target HbA1c level(HbA1c<7%) after 24 weeks(n=42, 35.3%) than before taking dapagliflozin(n=21, 17.6%). Blood pressure decreased 5.7 mmHg systolic blood pressure(SBP), 1.9 mmHg diastolic blood pressure(DBP) after 24 weeks. More than one quarter of participants(n=35, 29.4%) experienced weight loss. Most common adverse event was genitourinary symptoms. Conclusion: In this study, the effectiveness of dapagliflozin in improving glycemic control, blood pressure control, and weight loss was statistically significant. However, elderly and female patients, who have higher incidence of adverse events, should use dapagliflozin cautiously.

• Asian-Australasian Journal of Animal Sciences
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• 제23권9호
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• pp.1159-1165
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• 2010

Glucose is the main energy source for mammalian cells and its absorption is co-mediated by two different families of glucose transporters, sodium/glucose co-transporters (SGLTs) and facilitative glucose transporters (GLUTs). Here, we report the cloning and tissue distribution of porcine GLUT2. The GLUT2 was cloned by RACE and its cDNA was 2,051 bp long (GenBank accession no. EF140874). An AAATAA consensus sequence at nucleotide positions 1936-1941 was located upstream of the poly $(A)^+$ tail. Open reading frame analysis suggested that porcine GLUT2 contained 524 amino acids, with molecular weight of 57 kDa. The amino acid sequence of porcine GLUT2 was 87% and 79.4% identical with human and mouse GLUT2, respectively. GLUT2 mRNA was detected at highest level in porcine liver, at moderate levels in the small intestine and kidney, and at low levels in the brain, lung, muscle and heart. In the small intestine, the highest level was in the jejunum. In conclusion, the mRNA expression of GLUT2 was not only differentially regulated by age, but also differentially distributed along the small intestine of piglets, which may be related to availability of different intestinal luminal substrate concentrations resulting from different food sources and digestibility.