• YAKHAK HOEJI
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• v.55 no.4
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• pp.332-337
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• 2011

The purpose of this study was to investigate the effect of epigallocatechin gallate (EGCG) on the pharmacokinetics of nimodipine in rats. Pharmacokinetic parameters of nimodipine were determined in rats after oral and iv administration of nimodipine with or without EGCG and also the effect of EGCG on the cytochrome P450 (CYP) 3A4 and P-glycoprotein (P-gp) activity were evaluated. EGCG inhibited CYP3A4 and P-gp activity. EGCG significantly increased the area under the plasma concentration-time curve (AUC) and peak plasma concentration ($C_{max}$) of nimodipine. The absolute bioavailability (AB%) and relative bioavailability (RB%) of nimodipine by EGCG were increased by 16% and by 48%, respectively, compared to the control. In contrast, EGCG did not affect the intravenous pharmacokinetics of nimodipine. Based on these results, the increased bioavailability of nimodipine might be due to inhibition of CYP3A4 in the small intestine and/or in the liver and inhibition of P-gp in the small intestine by EGCG.

• YAKHAK HOEJI
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• v.54 no.5
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• pp.370-376
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• 2010

The aim of this study is to investigate the effect of apigenin on the pharmacokinetics of tamoxifen in rats. Tamoxifen was administered orally (10 mg/kg) or intravenously (2 mg/kg) without or with oral administration of apigenin (0.4, 2.0 or 8.0 mg/kg) to rats. The effect of apigenin on the P-glycoprotein (P-gp) and CYP3A4 activity was also evaluated. Apigenin inhibited CYP3A4 enzyme activity with 50% inhibition concentration ($IC_{50}$) of 1.8 ${\mu}M$. In addition, apigenin significantly enhanced the cellular accumulation of rhodamine 123 in MCF-7/ADR cells overexpressing P-gp. The plasma concentrations of tamoxifen were increased significantly by apigenin compared to control. The areas under the plasma concentration-time curve (AUC) and the peak concentrations ($IC_{max}$) of tamoxifen with apigenin were significantly higher than those of the control group. Consequently, the relative bioavailability (RB%) of tamoxifen with apigenin was 2-3-fold higher than the control, and absolute bioavailability (AB%) of tamoxifen were significantly higher (p<0.05 with co-administration, p<0.01 with pretreatment) than those of the control. The increased bioavailability of tamoxifen in rats with apigenin might be associated with the inhibition of an efflux pump P-glycoprotein and CYP3A4 by apigenin. From these results, dosage regimen of tamoxifen may be need to adjust when concomitantly administered with apigenin.

• Journal of Pharmaceutical Investigation
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• v.17 no.1
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• pp.15-21
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• 1987

Effects of phenobarbital pretreatment on the pharmacokinetics of enterohepatic recirculating griseofulvin were investigated by comparing normal to bile duct cannulated rats and also the effects of enhanced endogeneous bile flow on the absorption of griseofulvin were studied by means of in situ recirculation method in phenobarbital-pretreated rats. Phenobarbital was administered orally for five days at the dose of 75 mg/kg/day. The influence of phenobarbital pretreatment on the absorption rate constant, area under the plasma concentration-time curve, maximum plasma concentration of orally administered griseofulvin was not found in bile duct cannulated rats. Decreased absorption clearance and apparent partition coefficient of griseofulvin in accordance with the amount of endogeneous bile juice seemed to be due to the decrease of thermodynamic activity of griseofulvin as bile forms the micelle with griseofulvin.

• Journal of Microbiology
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• v.37 no.1
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• pp.1-9
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• 1999

The Biolog redox technology was carried out for evaluation of acidification effect on microbial communities at each stage of pH gradient microcosm. While the number of heterotrophic bacterial population and activities of extracellular enzyme decreased as the pH decreased, the number of total bacteria in the microcosm was not affected. The average color development of sample at each pH-gradient showed a sigmoidal curve, and at higher pH, more overall color development appeared in Biolog plates. Average color development value in Biolog plates was stabilized at 50 hours as an optimum incubation time. The color production in the Biolog plates was caused by cell density at above pH 5.0, but by cell activity below pH 4.0. Principal component analysis of color responses revealed distinctive patterns among the pH-gradient microcosm samples.

• Natural Product Sciences
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• v.23 no.2
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• pp.125-131
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• 2017

Clitoria ternatea or Commonly known blue pea, is a perennial climber crop native to Asian countries. The current study was aimed to evaluate the antimicrobial activity C. ternatea extract on food borne microorganisms and its antifungal effect on Penicillium expansum. The extract showed significant antimicrobial activity against 3 Gram positive bacteria, 2 Gram negative bacteria and 1 filamentous fungus on disc diffusion assay. The extract also showed good biocidal effect on all Gram positive bacteria tested and P. expansum. However, the kill curve analysis revealed that the fungicidal activity of the extract against P. expansum conidia was depend on the concentration of the extract and the time of exposure of the conidia to the extract. The scanning electron micrograph of the extract treated P. expansum culture showed alterations in the morphology of fungal hyphae. The germination of P. expansum conidia was completely inhibited and conidial development was totally suppressed by the extract, suggesting the possible mode of action of anthocyanin. Besides, the extract also exhibited 5.0-log suppression of microbial growth relative to control in the rice model. The results indicate the potential use of the C. ternatea anthocyanin as food biopreservative.

• Fashion & Textile Research Journal
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• v.16 no.3
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• pp.476-484
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• 2014

The purpose of this study was to investigate the dyeing properties and anti-microbial ability of silk and wool fabrics dyed with Terminalia chebula Retzius(TCR) extract using two extraction solvent, hot water and methanol. Dyeing properties of fabrics were studied by investigating the characteristics of colorant, changes in dye uptake under different dyeing conditions, and by investigating color change when mordants were applied. Also, color fastness, and antimicrobial activity of dyed fabrics were estimated. Regardless of extraction solvent type, colorant showed maximum absorption wavelength at 280 nm and 578 nm, which implied that tannin was the major pigment component of TCR. Also, through FT-IR spectrum result, it was confirmed that tannin of TCR methanol extract was hydrolysable tannin. But for the hot water extract, it was only assumed that its tannin was condenced tannin. Fabric dyed with hot water solvent extract showed higher dye uptake than fabric dyed with methanol solvent extract, dye uptake increasing by higher concentration of the dye, longer dyeing time and higher dyeing temperature. And the absorption curve between TCR extract and protein fiber was shaped in the form of Langmuir adsorption isotherm. Fabric dyed without mordant was yellow in color, and when dyed with mordant, fabric showed various colors depending on mordant types except Sn. Color fastness to washing was generally fine and color fastness to light was moderate. But color fastness to rubbing and dry cleaning was outstanding. Lastly, dyed fabrics showed very good antimicrobial activity of 99.9% against Staphylococcus aureus and Kiebsiella pneumoniae.

• Journal of Pharmaceutical Investigation
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• v.40 no.5
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• pp.291-296
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• 2010

This study was to investigate the effect of baicalein, an antioxidant, on the bioavailability of nicardipine after orally or intravenously administered nicardipine in rats. Nicardipine was administered orally (12 mg/kg) or intravenously (4 mg/kg) with or without orally administered baicalein (0.4, 2 or 10 mg/kg) to rats. In the inhibitory effect of baicalein on CYP3A4 activity, baicalein inhibited CYP3A4 activity with $IC_{50}$ values of 9.2 ${\mu}M$. The cell-based P-gp activity test using rhodamine-123 also showed that baicalein (30-10 ${\mu}M$, p<0.01) significantly inhibited P-gp activity. Compared with the control group (given nicardipine alone), the area under the plasma concentration-time curve (AUC) was significantly (2 mg/kg, P<0.05; 10 mg/kg, P<0.01) increased by 25.9-60.0%, and the peak concentration ($C_{max}$) was significantly (10 mg/kg, P<0.01) increased by 40.0% in the presence of baicalein after orally administration of nicardipine. Consequently, the relative bioavailability (R.B.) of nicardipine was increased by 1.26- to 1.60-fold and the absolute bioavailability (A.B.) was significantly (2 mg/kg, P<0.05; 10 mg/kg, P<0.01) increased by 26.0-59.9%. Compared to the i.v. control, baicalein did not significantly change pharmacokinetic parameters of nicardipine in i.v. administration. Accordingly, the enhanced oral bioavailability of nicardipine might be mainly due to increased intestinal absorption caused by P-gp inhibition rather than to reduced elimination of nicardipine by baicalein. The increase in the oral bioavailability might be mainly attributed to enhanced absorption in the small intestine via the inhibition of P-gp and reduced first-pass metabolism of nicardipine via the inhibition of the CYP3A subfamily in the small intestine and/or in the liver by baicalein. Based on these results, nicardipine dosage should be adjusted when given concomitantly with baicalein.

• Nuclear Engineering and Technology
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• v.34 no.6
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• pp.545-552
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• 2002

We developed an ultra low background gamma ray spectrometer particularly suitable for experiment which require lower detection limit. The background of a germanium spectrometer is suppressed by applying active and passive shielding technique at the same time. The active shielding devices consist of plastic scintillating plates of 50 mm thick and anti-coincidence electronic system. The shielding is made of 150 mm thick walls of very low activity lead,20 mm with activity of <10 Bq/kg and 130 mm with activity of <50 Bq/kg. The observed background count rates are 1.2 $s^{-1}$ and 0.36 $s^{-1}$ without and with the active shielding, respectively, overall the energy regions from 30 keV to 3 MeV The cosmic ray induced background is suppressed by a rate of 0.8 $s^{-1}$ at the present work. The detection efficiency curve necessary to obtain the radioactivity of environmental samples has been precisely determined on the energy regions from 80 to 2000 keV with a 10$^3$ ml marinelli beaker sample, consisting of the calibrated radionuclides $^{109}$ Cd, $^{57}$ CO, $^{139}$ Ce, $^{203}$ Hg, $^{113}$ Sn, $^{85}$Sr, $^{137}$ Cs, $^{60}$ Co and $^{88}$ Y. Virtues Of the method are demonstrated by measuring the activity of $^{137}$ Cs contained in the powdered milk.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.1
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• pp.10-19
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• 2020

Boron Neutron Capture Therapy (BNCT) has the advantage of selectively removing cancer cells ingesting boron compounds. In this study, the benefits for treatment time and boron compound injection dose were compared between current neutron sources and a high current neutron sources to be developed in near future. The time-activity curve (TAC) of GBM (Glioblastoma) for one bolus injection was obtained by applying modified 3 compartment model. The treatment time was determined for an accelerator-based neutron sources at the present time and a high current accelerator based neutron source to be developed in the near future. In the case of the double amount of IAEA-recommended neutron flux, the treatment time was shortened to 15 minutes. In the case of high current accelerators, which are five times the amount of IAEA-recommended neutron flux, the irradiation time is within 5 minutes. The use of a high current accelerator based neutron source in BNCT is advantageous in terms of treatment time. In addition, it can increase the efficiency of use of neutrons and reduce the boron compound injection dose to patients, thus reducing pharmacological toxicity.

• The Korean Journal of Nuclear Medicine
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• v.28 no.3
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• pp.371-376
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• 1994

To reevaluate the clinical usefulness of erection penography for diffential diagnosis of impotence, we reviewed retrospectively the data of penography in 56 patients who were diagnosed as impotence by various diagnostic workup. Twelve normal males were studied as control group. Papaverine HCl 30mg was injected into the corpus cavernosum and simultaneously $^{99m}Tc$-HSA 20mCi was injected via an antecubital vein. After injection radioactivities in the penile area were detected for 30 minutes by gamma camera and time activity curve was displayed. We defined that transit time(TT) is the time to reach peak activity and erection persistent time(EPT) is the duration of time to maintain peak activity and venous index(VI) is the ratio of radioactivity($R_{30}/R_{max}$). The results were as follows. The TT of arteriogenic group($10.7{\pm}2.8min$) was significantly increased compared with those of control and venogenic groups(P<0.05, respectively). The EPT of venogenic group ($6.2{\pm}6.8min$) is significantly decreased compared with those of control and arteriogenic groups(P<0.05, respectively). The TT of psychogenic($15.2{\pm}5.5min$) is significantly increased compared with those of control and arteriogenic groups(P<0.05, respectively). In conclusion erection penography was very useful for the diagnosis of vascular and psychogenic impotence and for differentiation between arteriogenic and venogenic but it could not differentiate mixed type or neurogenic from vascular or psychogenic.