Life Science R and nter

Seongnam, South Korea

Life Science R and nter

Seongnam, South Korea
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Kim A.,Chosun University | Jang D.-J.,Inje University | Shin H.-C.,Life Science R and nter | Jee U.,Chungnam National University | Jee J.-P.,Chosun University
Journal of Nanoscience and Nanotechnology | Year: 2017

Xenon anesthesia has several advantages over conventional anesthetics, however, it has not been widely used in clinical sites, since the cost and minimum alveolar concentration were higher than conventional inhalational anesthetics. The purpose of this study was to develop an optimum vehicle for stable intravenous delivery of xenon with sufficient concentration. Thermosensitive lipid based nano-emulsions (TS-LE) were prepared by blending medium chain triglyceride, polyethylene glycol-15-hydroxystearate, D-α tocopherol polyethylene glycol succinate and Poloxamer 188. Three folds higher xenon was loaded in TS-LE when it was prepared under 5.5 atm of xenon pressure compared to that under 1 atm of xenon pressure at 22°C (11.4±0.7 vs. 3.82±0.34 mg/ml). Poloxamer 188 conferred thermosensitive viscosity and outer rigid structure on TS-LE, and the properties led to the enhanced stability of xenon compared to usual lipid emulsion. Induction of anesthesia was investigated by monitoring loss of forepaw righting reflex (LORR) in rats. The ED50 for LORR was 131.9 mg/kg and the anesthesia was maintained for 65.3±7.1 sec at a dose of 179 mg/kg in rats. When it is considered that TS-LE stably loads enough concentration of xenon for the induction of therapeutically sufficient anesthesia, TS-LE may be regarded as a promising candidate for intravenous xenon delivery. Copyright © 2017 American Scientific Publishers All rights reserved.

Chae H.-S.,Dongguk University | Yoo H.,Life Science R and nter | Choi Y.H.,Dongguk University | Choi W.J.,Dongguk University | Chin Y.-W.,Dongguk University
Biological and Pharmaceutical Bulletin | Year: 2016

Maackiapterocarpan B, one of the pterocarpan analogs found in Sophora tonkinensis, is known to display pharmacological activities. However, the anti-inflammatory effects of maackiapterocarpan B and its molecular mechanism have yet to be clearly elucidated. In the present study, the effects of maackiapterocarpan B on macrophage-mediated inflammation in vitro were assessed. Maackiapterocarpan B inhibited the production of nitric oxide, the expression of tumor necrosis factor α, colony stimulating factor 2, interleukin-1β and interleukin-6, and the activation of nuclear factor-κB and mitogen-activated protein kinases in lipopolysaccharide-stimulated macrophages. These observations suggest the potential of maackiapterocarpan B in the treatment of inflammatory diseases. © 2016 The Pharmaceutical Society of Japan.

Kim T.K.,Seoul National University | Kim T.K.,Life Science R and nter | Yoo H.H.,Hanyang University | Kim E.J.,Life Science R and nter | And 3 more authors.
Pharmazie | Year: 2012

The purpose of this study was to evaluate the plasma-protein binding of docetaxel in two different formulations, Taxotere and SID530, a new docetaxel formulation with hydroxypropyl-beta-cyclodextrin (HP-β-CD), in human plasma in vitro, using equilibrium dialysis. Unbound docetaxel concentration in the human plasma was determined by LC-MS/MS analysis. SID530 showed a plasma-protein binding profile comparable to that of Taxotere in the clinically relevant concentration range of docetaxel. In both formulations, the unbound fraction of docetaxel increased in a concentration-dependent biphasic manner. The resulting data indicate that the excipient used in SID530, HP-β-CD, generates similar effects as polysorbate 80 of Taxotere in terms of plasma-protein binding of docetaxel.

Hyun Yoo H.,Hanyang University | Kon Kim T.,Life Science R and nter | Lee B.-Y.,Life Science R and nter | Kim D.-H.,Inje University
Mass Spectrometry Letters | Year: 2011

The pharmacokinetic properties of S-amlodipine were studied using racemic amlodipine and single S-enantiomer (SK310) administration to rats. Plasma levels of the drug were determined using chiral liquid chromatography coupled with tandem mass spectrometry following solid phase extraction. The stereospecific analysis of amlodipine was performed on an α-acid glycoprotein (AGP) column using a mobile phase comprising 10 mM ammonium acetate (pH 4.0) and propanol at a flow rate of 0.2 mL/min. This method was used to perform a comparative study of the pharmacokinetics of amlodipine and SK310. The results revealed that the pharmacokinetic profile of S-amlodipine after the administration of SK310 was comparable to that following the administration of the racemic mixture.

Jo H.J.,Seoul National University | Kim N.,Seoul National University | Nam R.H.,Seoul National University | Kang J.M.,Seoul National University | And 10 more authors.
American Journal of Physiology - Gastrointestinal and Liver Physiology | Year: 2014

Little is known about the time course of aging on interstitial cells of Cajal (ICC) of colon. The aim of this study was to investigate the change of morphology, ICC, and neuronal nitric oxide synthase (nNOS)-immunoreactive cells in the aged rat. The proximal colon of 344 Fischer rats at four different ages (6, 31, 74 wk, and 2 yr) were studied. The immunoreactivity of c-Kit, nNOS, anti-protein gene product 9.5, and synaptophysin were counted after immunohistochemistry. The c-kit, stem cell factor (ligand of Kit), and nNOS mRNA were measured by real-time PCR. c-Kit and nNOS protein were assessed by Western blot. Isovolumetric contractile force measurement and electrical field stimulation (EFS) were conducted. The area of intramuscular fat deposition significantly increased with age after 31 wk. c-Kit-immunoreactive ICC and nNOS-immunoreactive neurons and nerve fibers significantly declined with age. mRNA and protein expression of c-kit and nNOS decreased with aging. The functional study showed that the spontaneous contractility was decreased in aged rat, whereas EFS responses in the presence of atropine and L-NG-Nitroarginine methyl ester were increased in aged rat. In conclusion, the decrease of proportion of proper smooth muscle, the density of ICC and nNOS-immunoreactive neuronal fibers, and the number of nNOS-immunoreactive neurons during the aging process may explain the aging-associated colonic dysmotility. © 2014 the American Physiological Society.

Yoo H.,Seoul National University | Ryu K.H.,Life Science R and nter | Bae S.K.,Catholic University of Korea | Kim J.,Seoul National University
Journal of Separation Science | Year: 2014

A new liquid chromatography with tandem mass spectrometry method was developed and validated for the simultaneous determination of trifolirhizin, (-)-maackiain, (-)-sophoranone, and 2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran from Sophora tonkinensis in rat plasma using chlorpropamide as an internal standard. Plasma samples (50 μL) were prepared using a simple deproteinization procedure with 150 μL of acetonitrile containing 100 ng/mL of chlorpropamide. Chromatographic separation was carried out on an Acclaim RSLC120 C18 column (2.1 × 100 mm, 2.2 μm) using a gradient elution consisting of 7.5 mM ammonium acetate and acetonitrile containing 0.1% formic acid (0.4 mL/min flow rate, 7.0 min total run time). The detection and quantitation of all analytes were performed in selected reaction monitoring mode under both positive and negative electrospray ionization. This assay was linear over concentration ranges of 50-5000 ng/mL (trifolirhizin), 25-2500 ng/mL ((-)-maackiain), 5-250 ng/mL ((-)-sophoranone), and 1-250 ng/mL 2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran) with a lower limit of quantification of 50, 25, 5, and 1 ng/mL for trifolirhizin, (-)-maackiain, (-)-sophoranone, and 2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran, respectively. All the validation data, including the specificity, precision, accuracy, recovery, and stability conformed to the acceptance requirements. The results indicated that the developed method is sufficiently reliable for the pharmacokinetic study of the analytes following oral administration of Sophora tonkinensis extract in rats. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA.

Kang J.M.,Seoul National University | Kim N.,Seoul National University | Kim J.-H.,Life Science R and nter | Oh E.,Life Science R and nter | And 11 more authors.
American Journal of Physiology - Gastrointestinal and Liver Physiology | Year: 2010

Aging changes in the stomach lead to a decreased capacity for tissue repair in response to gastric acid. The aim of this study was to determine the mechanism associated with the increased susceptibility to injury of aging mucosa including reactive oxygen species (5), apoptosis, angiogenesis, and sensory neuron activity. Fischer 344 rats at four different ages (6, 31, 74 wk, and 2 yr of age) were studied. The connective tissue indicators [salt-soluble collagen and sulfated glycosaminoglycan (sGAG)], lipid hydroperoxide (LPO), myeloperoxidase (MPO), and hexosamine were assessed. We also evaluated the expression of early growth response-1 (Egr-1), phosphatase and tension homologue deleted on chromosome 10 (PTEN), caspase-9 (index of apoptosis), VEGF (index of angiogenesis), calcitonin gene-related peptide (CGRP, index of sensory neurons), and neuronal nitric oxide synthase (nNOS). The histological connective tissue area in the lower part of rat gastric mucosa increased with aging, with increase of salt-soluble collagen and sGAG. LPO and MPO in old rats were significantly greater than in the young rats, whereas hexosamine was significantly reduced. The old gastric mucosa had increased expression of Egr-1, PTEN, and caspase-9, whereas the VEGF, CGRP, and nNOS expression were significantly reduced. These results indicate that the lower part of rat gastric mucosa was found to be replaced by connective tissue with accumulation of oxidative products with aging. In addition, impairment of apoptosis, angiogenesis, and sensory neuron activity via the activation of Egr-1 and PTEN might increase the susceptibility of gastric mucosa to injury during aging. Copyright © 2010 the American Physiological Society.

Choi C.H.,Hanyang University | Kim T.-H.,Hanyang University | Sung Y.-K.,Hanyang University | Choi C.-B.,Hanyang University | And 3 more authors.
Korean Journal of Internal Medicine | Year: 2014

Background/Aims: SKI306X, a mixed extract of three herbs, Clematis mandshurica (CM), Prunella vulgaris (PV), and Trichosanthes kirilowii (TK), is chondroprotective in animal models of osteoarthritis (OA). The objectives of this study were to investigate its effect on interleukin (IL)-1β-induced degradation of glycosaminoglycan (GAG) and the basis of its action in human OA cartilage, as well as to screen for the presence of inhibitors of matrix metalloproteinase (MMP)-13 and a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS)-4 in SKI306X and its component herbs, as well as in fractions from SKI306X.Methods: Human OA chondrocytes and cartilage explants were obtained during total knee replacements and incubated with IL-1β ± oncostatin M with or without SKI306X or its component herb extracts. GAG degradation was assayed in cartilage explants using a commercial kit. Expression of genes involved in cartilage destruction was measured by real-time polymerase chain reaction using chondrocyte RNA. SKI306X was fractionated by preparative liquid chromatography to test for the presence of inhibitors of MMP-13 and ADAMTS-4.Results: SKI306X and PV inhibited IL-1β-induced GAG release from cartilage explants, and SKI306X, CM, PV, and TK inhibited IL-1β-induced MMP gene expression. Unexpectedly, SKI306X greatly stimulated IL-1β + oncostatin M-induced ADAMTS-4 gene expression, probably due to its TK component. Some fractions of SKI306X also inhibited ADAMTS-4 activity.Conclusions: SKI306X and its herbal components inhibit GAG degradation and catabolic gene expression in human OA chondrocytes and cartilage explants. SKI306X likely also contains one or more ADAMTS-4 inhibitor. © 2014 The Korean Association of Internal Medicine.

Kim T.K.,Life Science R and nter | Kim I.S.,Hanyang University | Hong S.H.,Life Science R and nter | Choi Y.K.,Research South, Inc. | And 2 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2013

In this study, we describe and validate a rapid and sensitive method for quantitation of dapoxetine in rat plasma by using ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI/MS/MS). Plasma samples were prepared by protein precipitation with acetonitrile, and sildenafil was used as an internal standard (IS). The mobile phase consisted of 0.5% formic acid/acetonitrile (60:40, v/v); a C18 reversed-phase column (2.0×50mm, 1.7μm) was used for chromatographic separation. Multiple reaction monitoring (MRM) was used in the positive ion mode for mass spectrometric detection. The calibration curve for dapoxetine was linear (r2=0.999) in the concentration range of 1-500ng/mL. The intra- and inter-day precision was between 3.8% and 8.3%, and the intra- and inter-day accuracy was between 101.1% and 109.0%. Dapoxetine was found to be stable in various conditions with the recoveries>87.0% (RSD <7.2%). The method was found to be specific, precise, and accurate, and no matrix effect was observed. Our results suggest that this method can be successfully applied in pharmacokinetic studies of dapoxetine in rat plasma. © 2013 Elsevier B.V.

Hwang Y.Y.,Korea Advanced Institute of Science and Technology | Hwang Y.Y.,Life Science R and nter | Shin D.C.,Life Science R and nter | Nam Y.S.,Korea Advanced Institute of Science and Technology | Cho B.-K.,Korea Advanced Institute of Science and Technology
Journal of Industrial and Engineering Chemistry | Year: 2012

β-Cyclodextrin (β-CD) is widely used to increase the stability, solubility, and bioavailability of poorly soluble drugs because of the appropriate size of its cavity. Sibutramine is a neurotransmitter reuptake inhibitor that has been investigated as an oral anorexiant. Here we report the complexation of sibutramine base with β-CD and the stability, dissolution, and pharmacokinetic properties of the sibutramine/CD complex. The formation of sibutramine/β-CD inclusion complexes is confirmed using differential scanning calorimetry, X-ray diffractometry, and 1H nuclear magnetic resonance. The thermal and photochemical stability of sibutramine is significantly improved by the complexation with β-CD, and the pharmacokinetic parameters (e.g., the plasma concentration, area under the curve, and maximum concentration of two active metabolites) for humans are comparable with those of the commercialized standard product (Reductil ®). Our study suggests that sibutramine/β-CD complexation can be of great use to increase the stability and biological efficacy of sibutramine base. © 2012 The Korean Society of Industrial and Engineering Chemistry.

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