• 약학회지
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• 제37권3호
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• pp.270-277
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• 1993

It is well known that lipidperoxide, formed in vivo, induced the denaturation of enzyme and destruction of cell membrane to acute injury of tissue. Aralia elata have physiological activates, the improvement of lipid metabolism, antidiabetic activity etc., which was thought to have the relationship to lipid peroxidation. The anti-lipidperoxidative effect of Aralia elata have not yet established. In this study, we examined the anti-lipidperoxidative effects of Aralia elata (Butanol fraction) on CCI$_{4}$ induced lipidperoxidation in rats, and elucidated the anti-lipidperoxidative mechanism. In rat liver homogenate intoxicated with CCI$_{4}$ (0.5 ml/100g), BuOH fraction of Aralia elata (80 mg/Kg/day) exhibited 85.41% anti-lipidperoxidative effect but in serum 69.63% inhibitory effects, respectively. In mitochondrial and microsomal fraction showed inhibition of 55.85% and 69.30%, respectively. In order to elucidate the mechanism of anti-lipidperoxidation effects of Aralia elata, enzymatic (NADPH dependent) and non-enzymatic (Ascorbic acid catalyzed) reaction, in vitro, were performed. In enzymatic reation, Aralia elata exhibited 59.43% anti-lipidperoxidation effects, but in non-enzymatic reaction exhibited 43.27% inhibition. Therefore, it is noteworthy that antioxidative power of them may mainly results from the inhibition by enzymatic reaction.

• 동의생리병리학회지
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• 제17권5호
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• pp.1335-1338
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• 2003

We have previously reported that the vasodilatory effect of BanhabackchuIChunma-tang(半夏白朮天麻湯; BCT), a herbal formula, and its mechanism might be associated with at least in part NO pathway. In the present study, we studied the influence of BanhabackchulChenuma-tang (BCT) on the phosphorylation of LC20, in parallel, the distribution of α-protein kinase C(PKCα) by phenylephrine was monitored using laser scan confocal immunofluorescent microscopy in freshly isolated ferret portal vein smooth muscle living single cells. Phenylephrine stimulation induced LC20 phosphorylation and translocation of PKCα. However, BCT dephosphorylated LC20 phosphorylation and inhibited the translocation of PKCα. Our results demonstrate that the mechanism of relaxant effect of BanhabackchulChunma-tang inhibition is associated with inhibition of PKCα activation and LC20 phosphorylation.

• Journal of Pharmaceutical Investigation
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• 제40권5호
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• pp.269-275
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• 2010

P-gp plays a critical role in drug disposition and represents a mechanism for the development of multidrug resistance. Flavonoids, a major class of natural compounds widely present in foods and herbal products, have been shown to inhibit P-gp. Therefore, the aim of this study was to identify new candidate chemosensitizers by screening various plant extracts. The ability of natural plant extracts to inhibit P-gp activity was assessed by measuring cellular accumulation of calcein AM, daunorubicin and vincristine in P-gp overexpressing MDCKII-MDR1 cells. Among more than 800 plant extracts, eight were found to inhibit P-gp activity. Curcuma aromatica extract produced greatest inhibition, followed by Curcuma longa and Dalbergia odorifera extracts. Extracts of Aloe ferox, Curcuma zedoariae rhizome, Zanthoxylum planispinum, and Ageratum conyzoides showed moderate inhibitory effects. Curcumin and quercetin exhibited similar inhibition of P-gpmediated efflux of daunorubicin and vincristine, and flavones had a lesser effect. When chemosensitizing effect was evaluated by measuring daunorubicin sensitivity to MDCKII-MDR1 cells in the presence of natural plant extracts, Curcuma aromatica showed the most potent chemosensitizing effect based on daunorubicin cytotoxicity. In conclusion, natural plant extracts such as Curcuma aromatica can potently inhibit P-gp activity and may have potential as a novel chemosensitizers.

• 대한전자공학회논문지SP
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• 제42권5호
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• pp.165-172
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• 2005

잡음이 존재하는 환경 하에서 음성인식을 실시하는 경우, 잡음을 제거하고 음성을 강조하는 시스템이 필요하다. 따라서 우수한 스펙트럴 분석기강인 인간의 청각계를 모의하는 것은 음성강조에 있어서 효과적이다. 이러한 것을 구현하는 하나의 방법으로서 상호억제라고 하는 청각기강을 적응적으로 사용하는 방법을 제안한다. 이것은 신경회로망에 의해서 잡음의 크기를 추정하여 각 프레임에 대해서 그 크기에 따라서 적응적으로 상호억제 계수와 진폭성분조정 계수를 조정함으로써 음성을 강조하는 방법이다. 스펙트럴왜곡율 척도의 평가로부터 백색잡음뿐만 아니라 유색잡음 및 자동차의 주행잡음에 대해서도 본 방식이 효과적이라는 것을 확인한다.

• Journal of Electrochemical Science and Technology
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• 제4권2호
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• pp.47-56
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• 2013

Inhibition performance of Lornoxicam & Tenoxicam against corrosion of carbon steel in 1M $H_2SO_4$ solutions was investigated by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. The inhibition efficiency increased with increasing inhibitor's concentration, but decreased with increase in temperature. Potentiodynamic polarization curves showed that, the inhibitors were of mixed type. The apparent activation energy ($E^*_a$) and other thermodynamic parameters for the corrosion process have also been calculated and discussed. The inhibition of carbon steel corrosion is due to the adsorption of the inhibitor molecules on the surface, which follows Temkin adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

• BMB Reports
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• 제30권2호
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• pp.157-161
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• 1997

The present paper reports characteristics and specificity of the inhibitory action of $N^{\alpha}-tosyl-L-lysine-chloromethyl\;ketone$ (TLCK) and $N^{\alpha}-tosyl-L-phenylalanine-chloromethyl\;ketone$ (TPCK) on the glucose6-phosphate transporter of rat liver microsomes. The TLCK-induced inhibition was pH dependent. The inhibition constants for TPCK were determined by following pseudo-Lst order reaction mechanism. The inhibition was protected by preincubation with excess amount of glucose-6-phosphate. The results proved that (a) TLCK inactivates the microsomal glucose-6-phosphate transporter, (b) the inhibition results from the modification of sulfhydryl groups of the transporter.

• 한국식품위생안전성학회:학술대회논문집
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• 한국식품위생안전성학회 2003년도 추계 국제심포지움 및 학술발표회
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• pp.46-46
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• 2003

Hypocholesterolemic peptide isolated from glycimin (11S protein) hydrolyzate by trypsin was purified and identified as LPYP and IAVPGEVA. To investigate the effects of phyiscal properties of side chains of the hypocholesterolemic activity, some of mutant peptides were designed and synthesized chemically. The structure related structures of each peptide were simulated and constructed and their conformations were observed by using spectropolarimeter. The hypocholesterolemic activities were monitored by assaying the inhibition of 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoA reductase) in vitro and by the determination of cholesterol content in mice serum. For LPYP derivatives, Hypocholesterolemic activity was lost when hydrophobic leucine residue at N-terminus was not so critical for maintaining hypocholesterolemic activity. For idealogical design of hypocholesterolemic peptides, the structure of HMG-CoA reductase are shown and inhibition mechanism of some peptides or inhibitors will be presented. For IAVPGEVA derivative inhibition of HMG-CoA reductase has been studied. For detail study of hypocholesterolemic activity, kinetic study of inhibition of peptides on HMG-CoA reductase and structural view of ligand binding should be investigated.

• 대한화학회지
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• 제58권1호
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• pp.25-32
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• 2014

Corrosion inhibition of 304 stainless steel (SS) in 1 M HCl by aqueous extract of coriander seeds was studied using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. Values of inhibition efficiency obtained are dependent upon the concentration of extract and temperature. Generally, inhibition was found to increase with inhibitor concentration, but decrease with temperature. Physical adsorption mechanism has been proposed for the inhibition with Langmuir adsorption isotherm obeyed. Values of activation energy of the inhibited corrosion reaction of 304 SS are greater than the value obtained for the blank. Thermodynamic consideration reveals that adsorption of aqueous extract of coriander seeds 304 SS surface is spontaneous.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.263-263
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• 1994

Annexin I is a member of the in family of calcium dependent phospholipid banding proteins and is an in vitro phospholipase $A_2$ (PLA$_2$) inhibitor. The mechanism of PLA$_2$ inhibition by annexin I is still ambiguous. The structure of annexin I was studied at the atomic level by using nuclear magnetic resonance (NMR), circular dichrotsm (CD) and fluorescence spectroscopy. Recombinant human annexin I and N-terminally truncated annexin I (1-31 deleted: d-annexin I) were purified and their NMR spectra were compared. The NMR spectra of the two were similar. When $Ca^{2+}$ ion added to annexin I ad d-annexin I, peak broadening occurred, but no significant spectroscopic change was observed. When porcine pancreatic PLA$_2$ was added to deuterium labeled annexin I, an interaction of annexin I with PLA$_2$ was observed as indicated by the disappearance and shift of several peaks in the NMR spectrum. This result supports a protein-protein interaction mechanism for PLA$_2$ inhibition by annexin I.I.

• 한국미생물·생명공학회지
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• 제18권1호
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• pp.39-43
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• 1990

본 저해물질은 10Mug의 Alpha-D-glucosidase에 대해서 50Mug 및 100Mug을 첨가했을 때 저해율은 각각 60, 80 정도였으며 enzyme-inhibitor complex를 비교적 서서히 형성하여 5분간 진처리하였을 때 약 55의 저해율을 나타내었다. 그리고 Alpha-D-glucosidase, Alpha-galactosidase및 Beta-galactosidase를 제외한 탄수화물 분해효소에 대해서는 저해능이 없었으며, Alpha-D-glucosidase에 대한 저해양상은 non-competitive type 이었으며 Ki 값은 118 $\mu$g/m$\ell$였다.