• Natural Product Sciences
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• v.17 no.2
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• pp.130-134
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• 2011

The purpose of this study was to evaluate the therapeutic potential of naturally occurring aldose reductase (AR) inhibitors isolated from Korean native plants. The MeOH extract and stepwise polarity fractions of dandelions were tested on rat lens AR inhibition in vitro. Of these, the EtOAc fractions from the leaves of dandelions (Traxacum coreanum, T. officinale, and T. ohwianum) exhibited an AR inhibitory activity ($IC_{50}$ values, 2.37, 1.73 and 2.68 ${\mu}g/ml$, respectively). A chromatography of the EtOAc fraction from the leaves of T. coreanum led to the further isolation of two flavonoids identified as luteolin and luteolin 7-O-glucopyranoside. These compounds exhibited strong AR inhibitory activity, with $IC_{50}$ values of 0.15 and 1.05 ${\mu}M$, respectively. These results suggested that luteolin is a potent AR inhibitor within dandelions and that it could be a useful lead compound in the development of a novel AR inhibitory agent against diabetic complications.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.4
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• pp.333-339
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• 2021

Injection lipolysis or mesotherapy gained popularity for local fat dissolve as an alternative to surgical liposuction. Phosphatidylcholine (PPC) and aminophyl-line (AMPL) are commonly used compounds for mesotherapy, but their efficacy and safety as lipolytic agents have been controversial. Glycerophosphocholine (GPC) is a choline precursor structurally similar to PPC, and thus introduced in aesthetics as an alternative for PPC. This study aimed to evaluate the effects of GPC on adipocytes differentiation and lipolysis and compared those effects with PPC and AMPL using in vitro and in vivo models. Adipogenesis in 3T3-L1 was measured by Oil Red O staining. Lipolysis was assessed by measuring the amount of glycerol released in the culture media. To evaluate the lipolytic activity of GPC on a physiological condition, GPC was subcutaneously injected to one side of inguinal fat pads for 3 days. Lipolytic activity of GPC was assessed by hematoxylin and eosin staining in adipose tissue. GPC significantly suppressed adipocyte differentiation of 3T3-L1 in a concentration-dependent manner (22.3% inhibition at 4 mM of GPC compared to control). Moreover, when lipolysis was assessed by glycerol release in 3T3-L1 adipocytes, 6 mM of GPC stimulated glycerol release by two-fold over control. Subcutaneous injection of GPC into the inguinal fat pad of mice significantly reduced the mass of fat pad and the size of adipocytes of injected site, and these effects of GPC were more prominent over PPC and AMPL. Taken together, these results suggest that GPC is the potential therapeutic agent as a local fat reducer.

• Korean Journal of Pharmacognosy
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• v.35 no.3 s.138
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• pp.244-249
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• 2004

The effects of hesperetin and naringenin on $NF-{\kappa}B$ activation were investigated in normal rat kidney cells transformed by temperature sensitive Rous Sarcoma Virus (tsNRK). The flavonoids, naringenin and hesperetin, significantly reduced v-Src-induced $NF-{\kappa}B$ activation as well as phosphorylation of Akt and GSK-3 in tsNRK cells, whereas these compounds did not effect on platelet-derived growth factor (PDGF)-induced $NF-{\kappa}B$ activation in $NIH3T3{\gamma}l$ cells. In addition, the DNA binding activity of SP-I was also reduced but that of AP-1 was not affected by the compounds. Our study suggests that Src-induced $NF-{\kappa}B$ activation could occur via Akt-GSK-3 pathway without $IkB{\alpha}$ degradation and that naringenin and hesperetin could be used in the treatment of cancer through the inhibition of $NF-{\kappa}B$ activation.

• Journal of Life Science
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• v.28 no.9
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• pp.999-1006
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• 2018

Obesity is epidemic worldwide and has reportedly been linked to the progression of several metabolic and cardiovascular diseases. The natural products are decreasing the side effects of medicines used for obesity and also have health benefits dut to their numerous bioactive compounds. In this context, Artemisia scoparia is a widespread plant that has been suggested as possessing various types of bioactivity. In this study, the crude extract from A. scoparia (ASE) was tested for its ability to suppress adipogenesis in mouse 3T3-L1 pre-adipocytes. The molecular pathway by which ASE affects differentiation of 3T3-L1 cells was also investigated. The introduction of ASE to differentiating 3T3-L1 pre-adipocytes resulted in suppressed adipogenesis, as confirmed by decreased intracellular lipid accumulation. The differentiating cells treated with 10 and $100{\mu}g/ml$ of ASE showed 21.9 and 29.0% less lipid accumulation, respectively, than untreated adipocytes. In addition, the results indicated that ASE treatment lowered the expression of the adipogenesis-related factors $PPAR{\gamma}$, $C/EBP{\alpha}$, and SREBP-1c. Furthermore, treating with ASE notably decreased levels of phosphorylated p38, ERK, and JNK in 3T3-L1 adipocytes. These results indicate that ASE exhibits significant anti-adipogenesis activity by downregulating the MAPK and $PPAR{\gamma}$ pathways during the differentiation of 3T3-L1 pre-adipocytes. Therefore, A. scoparia may be a potential source of natural products against obesity.

• Progress in Superconductivity and Cryogenics
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• v.25 no.2
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• pp.10-13
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• 2023

High-T_C superconductivity (HTSC) has been the central issue in the field of condensed matter physics for decades. An essential part of the research on superconductivity is finding new exotic superconductors. It was recently suggested that Ir-substituted La_0.7Sr_0.3MnO₃ (LSMIO) is a new high-T_C superconductor. However, systematic studies to experimentally verify the superconductivity have not been done. Here, we report the growth processes of LSMIO thin films and their electrical transport properties. We observed a clear negative correlation between the intensity of the laser utilized for film deposition and the Curie temperature of the deposited film. We attributed this effect to the suppression of Sr concentration in the LSMIO films as the laser intensity increased. However, our LSMIO films show conventional ferromagnetism instead of HTSC. To realize the HTSC in LSMIO systems, further exploration of diverse compositions of LSMIO compounds is essential.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.90-96
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• 2013

The anti-obesity effect of ethanol xtract and their fractions from Rumex Crispus L. on the differentiation of 3T3-L1 pre-adipocytes to adipocytes was investigated by suppressing adipocyte differentiation and lipid accumulation with Oil red O assay, western blot and real-time PCR analysis. Ethyl acetate fraction of Rumex crispus L. significantly inhibited adipocyte differentiation when treated during the adipocyte differentiation process, as assessed by measuring fat accumulation using Oil red O staining. In inducing differentiation of 3T3-L1 preadipocytes in the presence of an adipogenic cocktail, isobutylmethylxanthine (IBMX), dexamethasone- and insulin-along with ethyl acetate fraction residue processing treatment significantly decreased protein expression of obesity-related proteins, such as peroxisome-proliferators-activated-receptor-${\gamma}$ ($PPAR{\gamma}$) and CCAAT enhancer-binding-proteins ${\alpha}$ ($C/EBP{\alpha}$). These results indicate that ethyl acetate fraction of Rumex crispus L. is the most effective candidate for preventing obesity. However further studies will be needed to identify the active compounds that confer the anti-obesity activity of ethyl acetate fraction from Rumex crispus L.

• Toxicological Research
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• v.23 no.3
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• pp.223-229
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• 2007

Conjugated linoleic acid (CLA) has been recently reported to have an anti-obesity effect in animals and humans. The objective of this study was to investigate effects of diglyceride (DG)-CLA on proliferation and differentiation of 3T3-L1 preadipocytes. Cell proliferation was determined using WST-8 analysis and cell differentiation was determined by glycerol-3-phosphate dehydrogenase (GPDH) activity. Lipid accumulation in differentiating 3T3-L1 cells was determined by Oil red O staining. There were four experimental groups including vehicle control (DMSO), CLA, triglyceride (TG)-CLA, and DG-CLA. Treatments of CLA, TG-CLA, and DG-CLA at the concentrations of $10{\sim}1000{\mu}g/ml$ reduced proliferation of preconfluent 3T3-L1 cells in a dose-dependent manner. Among them CLA was the most effective in the proliferation inhibition of preconfluent 3T3-L1 cells with increasing concentrations. Treatments of CLA and DG-CLA at the concentration of $100{\mu}g/ml$ significantly inhibited differentiation of postconfluent 3T3-L1 cells as measured by GPOH activity (p<0.05). In addition, treatments of CLA, TG-CLA, and DG-CLA effectively inhibited lipid accumulation during differentiation of 3T3-L 1 cells. OG-CLA had the most inhibitory effect on the differentiation and lipid accumulation. These results suggest that the compounds including CLA have a respectable anti-obesity effect and that consumption of DG-CLA as a dietary oil may give a benefit for controlling overweight in humans.

• Journal of Conservation Science
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• v.29 no.2
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• pp.139-147
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• 2013

This study focused on iron making related information through analyzing slags and furnace wall collected from iron production site of Suryong-ri Wonmorongi, Chungju. Total Fe content of slags were from 36.98% to 44.47% and this range was general recovery rate of iron in ancient. Compounds of calcium included slags was supposed to add intentionally during smelting process as deoxidation agent in order that these helped to separate iron from impurities. Furnace wall didn't make of high alumina clay because of low $Al_2O_3$. Microstructure and main components of slags show that No. 1 to 3 slags with fayalite and wustite were products of iron ore smelting. However, No.4 slag is more likely to smelt by iron sand because of ulvospinel with $TiO_2$ in No. 4 slag. Therefore, iron ore were not only used but iron sand in smelting and furnace wall made of general clay with low $Al_2O_3$ content in this area.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.804-811
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• 2001

In many Gram-negative bacteria, autoinducers, such as N-acyl-L-homoserine lactone(acyl-HSL) and its derivative molecules, mediate the cell-density-dependnet expression of certain operons. The current study identified the autoinducers produced by Burkholderia cepacia G4, a trichloroethylene-degrading lagoon isolate, using TLC bioassays with Agrobacterium tumefaciens NT1(pDCI141E33) and Chromobacterium violaceum CVO26, and a GC-MS analysis. The ${R_f}\;and\;{R_t}$ values and mass spectra were compared with those of synthetic compounds. Based on the analyses, it was confirmed that G4 produces N-hexanoyl (C6)-, N-octanoyl (C8)-, N-decanoyl (C10)-, N-dodecanoyl (C12)-HSL, and an unknown active species. The integration of the GC peak areas exhibited a ratio of C8-HSL:C10-HSL:C12-HSL at 3:17:1 with C6-HSL and C10-HSL production at trace and micromolar levels, respectively, in the culture supernatants. Nutants partially defective in producing acyl-HSLs were also partially defective in the biosynthesis of an antibiotic substance. These results indicate that the autoinducer-dependent gene regulation in G4 is dissimilar to the clinical B. cepacia strains isolated from patients with cystic fibrosis.

• Korean Journal of Materials Research
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• v.13 no.2
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• pp.106-110
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• 2003

Nano-sized powders of Indium Tin Oxide(ITO) were synthesized by a coprecipitation method. In order to investigate the gas sensing characteristics in the nanocrystalline ITO thick films with various particle sizes, ITO powders with the average particle diameter of 15, 30, and 70 nm respectively were synthesized. And the sensitivity of ITO thick films was measured upon exposure to a target gas($C_2$$H_{5}$ /OH) and some other Volatile Organic Compounds(VOCs), such as, toluene, methanol, benzene, chloroform. As a result, ITO thick films had high sensitivity for ethanol and higher sensitivity with smaller particle size.