• Title/Summary/Keyword: glucose uptake activity

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4-Acetoxyscirpendiol of Paecilomyces tenuipes Inhibits Na+/D-Glucose Cotransporter Expressed in Xenopus laevis Oocytes

  • Yoo, Oc-Ki;Son, Joo-Hiuk;Lee, Dong-Hee
    • BMB Reports
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    • v.38 no.2
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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.

Studies on the Biological Activity of Pleurotus ferulea (아위버섯(Pleurotus ferules) 추출물의 생리활성 탐색)

  • 홍기형;김병용;김혜경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.5
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    • pp.791-796
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    • 2004
  • This study was peformed to screen the biological activities of Pleurotus ferulea (K5 and K8 strains). The cap of K5 strain is well developed than stalk, and vice versa in K8. The ethanol extract of Pleurotus ferulea exhibited significant free radical scavenging activity (35∼36%), suggesting possible effect on many degenerative diseases originated from the reaction of oxygen species. Acetylcholinesterase inhibitor is proven to be the most effective factor for Alzheimer disease induction, and ethanol extract of Pleurotus ferulea significantly inhibited acetylcholinesterase activity (25∼35%) in uitro. Moreover, ethanol extract of Pleurotus ferulea suppressed liver fibrosis by 3∼12% in uitro. However, Pleurotus ferulea feruled to inhibit glucose uptake in human intestinal cell line. Viability of gastric and colon cancer cells was also not affected by Pleurotus ferulea extract. In conclusion Pleurotus ferulea exhibited significant effect on free radical scavenging, acetylcholinesterase inhibiton and brain cell protection. However, Pleurotus ferulea failed to affect glucose uptake, and cytotoxicity of gastric and cancer cells. In general, K8 revealed more significant effects than K5.

Effect of Ethanol on $Na^+-P_i$ Uptake in Opossum Kidney Cells: Role of Membrane Fluidization and Reactive Oxygen Species

  • Park, In-Ho;Hwang, Moon-Young;Woo, Jae-Suk;Jung, Jin-Sup;Kim, Yong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.5
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    • pp.529-538
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    • 1999
  • This study was undertaken to examine the effect of ethanol on $Na^+ -dependent$ phosphate $(Na^+-P_i)$ uptake in opossum kidney (OK) cells, an established renal proximal tubular cell line. Ethanol inhibited ^Na^+-dependent$ component of phosphate uptake in a dose-dependent manner with $I_{50}$ of 8.4%, but it did not affect $Na^+-independent$ component. Similarly, ethanol inhibited $Na^+-dependent$ uptakes of glucose and amino acids (AIB, glycine, alanine, and leucine). Microsomal $Na^+-K^+-ATPase$ activity was not significantly altered when cells were treated with 8% ethanol. Kinetic analysis showed that ethanol increased $K_m$ without a change in $V_{max}$ of $Na^+-P_i$ uptake. Inhibitory effect of n-alcohols on $Na^+-P_i$ uptake was dependent on the length of the hydrocarbon chain, and it resulted from the binding of one molecule of alcohol, as indicated by the Hill coefficient (n) of 0.8-1.04. Catalase significantly prevented the inhibition, but superoxide dismutase and hydroxyl radical scavengers did not alter the ethanol effect. A potent antioxidant DPPD and iron chelators did not prevent the inhibition. Pyrazole, an inhibitor of alcohol dehydrogenase, did not attenuate ethanol-induced inhibition of $Na^+-P_i$ uptake, but it prevented ethanol-induced cell death. These results suggest that ethanol may inhibit $Na^+-P_i$ uptake through a direct action on the carrier protein, although the transport system is affected by alterations in the lipid environment of the membrane.

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Effect of Cinnamomum camphora Leaf Fractions on Insulin Action (3T3-L1 지방세포에서 녹나무 잎 추출분획물이 인슐린작용에 미치는 효과)

  • Ko, Byoung-Seob;Lee, Mi-Young;Kim, Ho-Kyoung;Chun, Jin-Mi;Choi, Soo-Bong;Jun, Dong-Wha;Jang, Jin-Sun;Park, Sunmin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.9
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    • pp.1336-1343
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    • 2005
  • In the present study, we screened candidates for enhancing insulin action and secretion from Cinnamomum camphora (CC) fractions, in 3T3-L1 adipocytes and Min6 cells by investigating insulin- stimulated glucose uptake and glucose-stimulated insulin secretion, respectively. CC were extracted by $70\%$ ethanol followed by XAD-4 column chromatography with serial mixture solvents of methanol and water, and the fractional extractions were utilized for determining insulin action and secretion, and $\alpha$-glucoamylase suppressing activity, A significant insulin-stimulated glucose uptake was observed in 3T3-L1 adipocytes, giving 0.5 or $5{\mu}g/mL$ of $40\%\;and\;60\%$ methanol fractions plus 0.2 nM insulin, compared to the treatment of DMSO plus 0.2 nM insulin. The treatments of $40\%\;and\;60\%$ methanol fractions plus 0.2 nM insulin reached the glucose uptake of 10 nM insulin treatment. The $40\%$ methanol fraction increased triglyceride accumulation by stimulating differentiation and triglyceride synthesis similar to pioglitazone, PPAR-$\gamma$ agonist. No inhibition of $\alpha$-glucoamylase activity of CC fractions was observed. They did not modulate the insulin secretion capacity In either low or high glucose media. These results suggest that $40\%$ methanol fraction contains a potential insulin sensitizer to have a similar function of PPAR-$\gamma$ agonist. Crude CC extract may improve glucose utilization by enhancing insulin-stimulated glucose uptake without elevating glucose stimulated insulin secretion.

Potential Utility of FDG PET-CT as a Non-invasive Tool for Monitoring Local Immune Responses

  • Lee, Seungho;Choi, Seohee;Kim, Sang Yong;Yun, Mi Jin;Kim, Hyoung-Il
    • Journal of Gastric Cancer
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    • v.17 no.4
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    • pp.384-393
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    • 2017
  • Purpose: The tumor microenvironment is known to be associated with the metabolic activity of cancer cells and local immune reactions. We hypothesized that glucose metabolism measured by 2-deoxy-2-($^{18}F$)fluoro-D-glucose ($^{18}F-FDG$) positron emission tomography (PET)-computed tomography (CT) ($^{18}F-FDG$ PET-CT) would be associated with local immune responses evaluated according to the presence of tumor infiltrating lymphocytes (TILs). Materials and Methods: We retrospectively reviewed 56 patients who underwent $^{18}F-FDG$ PET-CT prior to gastrectomy. In resected tumor specimens, TIL subsets, including cluster of differentiation (CD) 3, CD4, CD8, Forkhead box P3 (Foxp3), and granzyme B, were subjected to immunohistochemical analysis. The prognostic nutritional index (PNI) was calculated as: ($10{\times}serum$ albumin value)+($0.005{\times}peripheral$ lymphocyte counts). Additionally, the maximum standard uptake value ($SUV_{max}$) was calculated to evaluate the metabolic activity of cancer cells. Results: The $SUV_{max}$ was positively correlated with larger tumor size (R=0.293; P=0.029) and negatively correlated with PNI (R=-0.407; P=0.002). A higher $SUV_{max}$ showed a marginal association with higher CD3 (+) T lymphocyte counts (R=0.227; P=0.092) and a significant association with higher Foxp3 (+) T lymphocyte counts (R=0.431; P=0.009). No other clinicopathological characteristics were associated with $SUV_{max}$ or TILs. Survival analysis, however, indicated that neither $SUV_{max}$ nor Foxp3 held prognostic significance. Conclusions: FDG uptake on PET-CT could be associated with TILs, especially regulatory T cells, in gastric cancer. This finding may suggest that PET-CT could be of use as a non-invasive tool for monitoring the tumor microenvironment in patients with gastric cancer.

Changes in Brain Activity of Rats due to Exposure to Fine Dust Using 18F-FDG PET (18F-FDG PET를 이용한 미세먼지 노출에 따른 쥐(rat)의 뇌 활성도 변화)

  • Cho, Yun-Ho;Cho, Kyu-Sang;Lee, Wang-Hui;Choi, Jea-Ho
    • Journal of radiological science and technology
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    • v.45 no.3
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    • pp.225-232
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    • 2022
  • Fine dust threatens human health in various forms, depending on the particle size, such as by causing respiratory, cardiovascular, and brain diseases, after entering the body via the lungs. The aim of this study was to correlate fine dust exposure with changes in brain blood flow in Sprague Dawley rats by using micro-positron emission tomography and elucidate the possibility of developing cerebrovascular diseases caused by fine dust. The subjects were exposured to an average fine dust (particulate matter 2.5) of 206.2 ± 7.74 to ten rats four times a day, twice a day for 90 min. Before the experiment, they were maintained at NPO to the maximize the intake of 18F-fluorodeoxy glucose(18F-FDG) and minimize changes in the 18F-FDG biomass depending on the ambient environment and body temperature of the rats. PET images were acquired in the list mode 40 min after injecting 18F-FDG 44.4 MBq into the rats tail vein using a micro-PET scanner pre and post exposure to fine dust. We found that the whole brain level of 18F-FDG standardized uptake value in rats averaged 5.21 ± 0.52 g/mL pre and 4.22 ± 0.48 g/mL post exposure to fine dust, resulting in a statistically significant difference. Fine dust was able to alter brain activity after entering the body via the lungs in various forms depending on the particle size.

Inhibitory Effect of Ginsenoside-Rp1, a Novel Ginsenoside Derivative, on the Functional Activation of Macrophage-like Cells

  • Park, Tae-Yoon;Cho, Jae-Youl
    • Biomolecules & Therapeutics
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    • v.16 no.4
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    • pp.370-376
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    • 2008
  • Ginsenoside Rp1 (G-Rp1) is a ginseng saponin derivative with chemopreventive and anti-cancer activities. In this study, we examined the regulatory activity of G-Rp1 on the functional activation of macrophages. G-Rp1 remarkably inhibited TNF-$\alpha$ production, LPS-induced cell cytotoxicity, NO production, ROS generation, and phagocytic uptake from lipopolysacchride (LPS)-activated RAW264.7 cells. According to structural feature study using several G-Rp1 analogs, two carbohydrates (glucose-glucose) at R1 position were observedto be highly effective, compared to other structural derivatives. Although the inhibitory activities of G-Rp1 on macrophage functions were not remarkable, several points that G-Rp1 was known to be safe, and that this compound was orally effective, suggest that G-Rp1 may be beneficial in treating macrophage-mediated immunological diseases.

The Glycopeptide, a Promoter of Thymidine Uptake, from Aloe Vera

  • Yang, Mi-Rim;Kang, Chun-Geun;Roh, Yeon-Suk;Son, Byeng-Wha;Choi, Hong-Dae;Park, Young-In;Lee, Seung-Ki;Choi, Sung-Won;Chung, Myung-Hee
    • Natural Product Sciences
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    • v.4 no.2
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    • pp.62-67
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    • 1998
  • As a part of search for new biologically active constituents from aloe, we have isolated a glycopeptide, called G1G1M1DI2, from the gel(G1) of Aloe vera. Chemical and spectroscopic evidence indicated that G1G1M1DI2 is a glycopeptide. The molecular weight of G1G1M1DI2 was about 5,500 daltons, and the carbohydrate and protein contents were 20.9% and 32.6%, respectively. Periodate oxidation and enzymic degradation gave peptide moiety and carbohydrate moiety, respectively. Carbohydrate moiety is composed of fucose, galactose, glucose and mannose in a molar ratio of 0.5:2.4;48.8:48.3. Peptide moiety is composed of fifteen amino acids, and glutamic acid and glycine were the major componants. The glycopeptide, G1G1M1DI2, stimulated thymidine uptake of SCC 13 cells about 6.5 times the control. This result suggests that this glycopeptide has a skin cell proliferating activity.

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Fibroin Enhances Insulin Sensitivity and Reverses Insulin Resistance in 3T3-L1 Adipocytes

  • Hyun Chang-Kee;Frost Susan C.
    • Proceedings of the Korean Society of Food Science and Nutrition Conference
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    • 2004.11a
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    • pp.185-197
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    • 2004
  • Type 2 diabetes is characterized by hyperglycemia and hyperinsulinemia, features of insulin resistance. In vivo treatment of ob/ob mice with hydrolyzed fibroin reverses these pathological attributes (6). To explore the mechanism underlying this effect, we have used the 3T3-Ll adipocytes as a cell type which would represent the periphery, in vivo. Exposure of 3T3-Ll adipocytes to chronic insulin leads to the a 50% loss of insulin-stimulated glucose uptake. Chronic exposure to fibroin blocked, in part, the response to chronic insulin but also increased the sensitivity of control cells to the acute action of insulin. The later effect was most robust at physiological concentrations of insulin. Fibroin did not prevent the insulin-induced down-regulation of the insulin receptor or the tyrosine kinase activity associated with the receptor. Further, fibroin had no affect on the loss in activity of the insulin-sensitive down-stream kinase, Akt. Interestingly, fibroin accelerated glucose metabolism and glycogen turnover independent of insulin action. In addition, fibroin up-regulated GLUT1 which increased its expression at the cell surface and caused the redistribution of GLUT4 to the plasma membrane. Together, these later effects would lead to an improvement in hyperglycemia in vivo which would in turn reduce the need for insulin.

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Effect of Ginseng Saponin on the Protein Biosynthesis of E. coli Cells (인삼사포닌 분획이 E. coli 세포의 단백질 합성에 미치는 영향)

  • Go, Ji-Hun;Lee, Hui-Bong;Ju, Chung-No
    • Journal of Ginseng Research
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    • v.7 no.1
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    • pp.68-73
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    • 1983
  • E. coli (K-12 W1485) was grown in M9 minimal medium containing ginseng saponin (10-3%-2%) and found that the cells grew most rapidly in the presence of 10-1% saponin. The cells, harvested at the early exponential phase, were transferred to the minimal medium containing 10-1% saponin plus 14C-labelled saponin (0.03 ${\mu}$Ci) and the incubation was continued at 37$^{\circ}C$ for 20 minutes and the cells were fractionated into the outermembrane, innermembrane and cytosol fraction. Radioactivity data showed that the most radioactivity was detected in the innermembrane. The activity of succinate dehydrogenase of the cells grown in the above saponin medium was significantly higher than that of the cells grown in ordinary minimal medium. No significant difference of the glucose 6-phosphate dehydrogenase activity was observed between the two groups. It was also found that the saponin stimulated glucose uptake and biosynthisis of lipids and proteins of the cells. Incorporation of 14C-leucine into the protein fraction of the cell was also accelerated.

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