• 한국임상약학회지
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• 제16권1호
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• pp.57-62
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• 2006

The purpose of this study was to investigate the effect of naringenin, one of flavonoids, on the pharmacokinetics and bioavailability of diltiazem (15 mg/kg) after oral administration of diltiazem with or without naringenin (2.0, 10 and 20 mg/kg) in rabbits. Coadministration of naringenin increased the absorption rate constant $(K_a)$, the area under the plasma concentration-time curve (AUC) and peak concentration $(C_{max})$ of diltiazem compared to the control group, but only significantly (p<0.05) by 10mg/kg of naringenin coadministration. The absolute bioavailability (AB%) of diltiazem by coadministration ranges from 7.8% to 10.3%, increased more than control (7.2%), and relative bioavailability (RB%) of diltiazem is increased from 1.08- to 1.43-fold. Coadministration caused on significant changes in the terminal half-lives $(t_{1/2})$ and the time to reach the peak concentration $(T_{max})$ of diltiazem. On the other hand, coadministration of naringenin increased the AUC desacetyldiltiazem, significantly at the dose of 10mg/kg. But the metabolite ratio (MR) was decreased, significantly at 10mg/kg of naringenin. Based on these results, we can make a conclusion that the increased bioavailability and the significant changes of these pharmacokinetic parameters might be due to naringenin, which possess the potency to inhibit the metabolizing enzyme (CYP3A4) in the liver and intestinal mucosa, and also inhibit the P-glycoprotein efflux pump in the intestinal mucosa.

• Biomolecules & Therapeutics
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• 제15권2호
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• pp.102-107
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• 2007

Cimetidine, a substrate for P-glycoprotein (P-gp), is a well known drug interacting with a variety of drugs and results in alteration of pharmacokinetic parameters by concomitant administration. The aim of present study was to investigate whether cimetidine affects the transport of various quinolone antibiotics in human colorectal cancer cell line (Caco-2) system which has been typically used to investigate drug transport via P-gp. The apparent permeability coefficients (P$_{app}$) value of 9 quinolone antibiotics in the co-treatment with cimetidine was examined. Apical to basolateral (AP-to-BL) transport of fleroxacin in the co-treatment with cimetidine was increased to 1.5-fold (p<0.01) compared with that of fleroxacin alone, whereas basolateral to apical (BL-to-AP) transport of fleroxacin was decreased to 0.83-fold significantly (p<0.05). Ofloxacin was decreased to 0.8-fold (p<0.01) and 0.72-fold (p<0.01) significantly in AP-to-BL and BL-to-AP direction, respectively by cimetidine cotreatment. The P$_{app}$ values of gatifloxacin, moxifloxacin, ciprofloxacin and rufloxacin also were changed by cimetidine. These results have a potential that cimetidine influences on the pharmacokinetics of quinolone antibiotics. It suggests that careful drug monitoring and dosage adjustment may be necessary during the co-administration of quinolone antibiotics with cimetidine.

• 한국임상약학회지
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• 제23권4호
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• pp.322-326
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• 2013

Purpose: Telmisartan, an angiotensin receptor blocker has been known to be a potent blocker of both CYP2J2 and P-glycoprotein (P-gp) in vitro. This study aims to investigate the drug-drug interactions between telmisartan and ebastine, a CYP2J2 and P-gp substrate in rats. Method: Ebastine (10 mg/kg) was orally given in the presence and absence of telmisartan (4 mg/kg, p.o.). Heparinized blood was serially taken and the plasma concentrations of ebastine and its three metabolites (hydroxyebastine, carebastine and desalkylebastine) were determined using LC-MS/MS, and their pharmacokinetic parameters were compared. Results: Peak concentrations ($C_{max}$) and AUC of ebastine were significantly (p<0.05) increased in the presence of telmisartan by 2.1 and 1.9 times, respectively. While $C_{max}$ of hydroxyebastine was significantly increased by 1.9 times, the half-life of hydroxyebasteine was decreased significantly with telmisartan (p<0.05). There was no change in the pharmacokinetic parameters of carebastine, the active metabolite of ebastine, and desalkylebastine was not detected in plasma. The systemic exposure of ebastine was significantly augmented by telmisartan, indicating that telmisartan may enhance the absorption of ebastine by blocking P-gp. Conclusion: Although telmisartan may also partially contribute to inhibit the biotransformation to hydroxyebastine, the inhibitory action seemed to be overridden by the enhancement of absorption, because the generation of hydroxyebastine was not diminished. In spite of such interactions between telmisartan and ebastine, no clinical consequence could be expected due to no significant change of the active metabolite, carebastine.

• Asian-Australasian Journal of Animal Sciences
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• 제19권5호
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• pp.632-637
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• 2006

Oviduct-specific glycoprotein 1 (OVGP1) is implicated in playing a role in fertilization and early embryo development. In this study, we have obtained the sequence of intron 9 of OVGP1 gene in swine. Comparative sequencing of Meishan (a native Chinese breed) and Large White pig breeds revealed an A/T substitution at position 943. A PCR-EcoRI-RFLP assay was developed to detect this mutation. Polymorphism analysis in Qingping animals showed that pigs with BB genotype had lower number of piglets born alive (NBA) in multiple parities than pigs with AA (p<0.05) and AB genotype (p<0.01). In Large $White{\times}Meishan$ ($LW{\times}M$) $F_2$ offspring, the weight of both ovaries (OW) of the BB genotype was significantly lighter than that of AB (p = 0.05) and AA (p<0.01) genotypes. Analysis of the data also revealed that the mutation locus affected these two traits mostly by additive effects. These studies indicated that the polymorphism was associated with NBA and OW in two distinct populations and further investigations in more purebreds or crossbreds are needed to confirm these results.

• Biomolecules & Therapeutics
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• 제18권3호
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• pp.343-349
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• 2010

This study was designed to investigate the effects of ticlopidine on the pharmacokinetics of carvedilol after oral or intravenous administration of carvedilol in rats. Carvedilol was administered orally (3 mg/kg) or intravenously (1 mg/kg) without or with oral administration of ticlopidine (4, 12 mg/kg) to rats. The effects of ticlopidine on P-glycoprotein (P-gp) and cytochrome P450 (CYP) 2C9 activity were also evaluated. Ticlopidine inhibited CYP2C9 activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of $25.2\;{\mu}M$. In addition, ticlopidine could not significantly enhance the cellular accumulation of rhodamine 123 in MCF-7/ADR cells overexpressing P-gp. Compared with the control group (given carvedilol alone), the area under the plasma concentration-time curve (AUC) was significantly (12 mg/kg, p<0.05) increased by 14-41%, and the peak concentration ($C_{max}$) was significantly (12 mg/kg, p<0.05) increased by 10.7-73.3% in the presence of ticlopidine after oral administration of carvedilol. Consequently, the relative bioavailability (R.B.) of carvedilol was increased by 1.14- to 1.41-fold and the absolute bioavailability (A.B.) of carvedilol in the presence of ticlopidine was increased by 36.2-38.5%. Compared to the i.v. control, ticlopidine could not significantly change the pharmacokinetic parameters of i.v. administered carvedilol. The enhanced oral bioavailability of carvedilol may result from inhibition of CYP2C9-mediated metabolism rather than P-gpmediated efflux of carvedilol in the intestinal and/or in liver and renal eliminatin of carvedilol by ticlopidine.

• Archives of Pharmacal Research
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• 제26권9호
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• pp.768-772
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• 2003

Tween 80 (Polysorbate 80) is a hydrophilic nonionic surfactant commonly used as an ingredient in dosing vehicles for pre-clinical in vivo studies (e.g., pharmacokinetic studies, etc.). Tween 80 increased apical to basolateral permeability of digoxin in Caco-2 cells suggesting that Tween 80 is an in vitro inhibitor of P-gp. The overall objective of the present study was to investigate whether an inhibition of P-gp by Tween 80 can potentially influence in vivo absorption of P-gp substrates by evaluating the effect of Tween 80 on the disposition of digoxin (a model P-gp substrate with minimum metabolism) after oral administration in rats. Rats were dosed orally with digoxin (0.2 mg/kg) formulated in ethanol (40％, v/v) and saline mixture with and without Tween 80 (1 or 10％, v/v). Digoxin oral AUC increased 30 and 61％ when dosed in 1 ％ and 10％ Tween 80, respectively, compared to control (P＜0.05). To further examine whether the increase in digoxin AUC after oral administration of Tween 80 is due, in part, to a systemic inhibition of digoxin excretion in addition to an inhibition of P-gp in the GI tract, a separate group of rats received digoxin intravenously (0.2 mg/kg) and Tween 80 (10％ v/v) orally. No significant changes in digoxin IV AUC was noted when Tween 80 was administered orally. In conclusion, Tween 80 significantly increased digoxin AUC and Cmax after oral administration, and the increased AUC is likely to be due to an inhibition of P-gp in the gut (i.e., improved absorption). Therefore, Tween 80 is likely to improve systemic exposure of P-gp substrates after oral administration. Comparing AUC after oral administration with and without Tween 80 may be a viable strategy in evaluating whether oral absorption of P-gp substrates is potentially limited by P-gp in the gut.

• Journal of Plant Biology
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• 제38권4호
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• pp.349-357
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• 1995

The alkaline invertase ($\beta$-D-fructofuranoside fructohydrolase, EC 3.2.1.26) was isolated and characterized from the hypocotyls of mung bean (Phaseolus radiatus L.). The enzyme was purified by consecutive step using diethylaminoethyl (DEAE)-cellulose anion exchange, 1st Sephadex G-200, DEAE-Sephadex A50 and 2nd Sephadex G-200 chromatography. The overall purification was about 77-fold with a yield of about 6%. The finally purified enzyme exhibited a specific activity of about 48 $\mu$mol of glucose produced mg-1 protein min-1 at pH 7.0 and appeared to be a single protein by nondenaturing polyacrylamide gel electrophoresis (PAGE). The enzyme had the native molecular weight of 450 kD and subunits molecular weight of 63 kD and 38 kD as estimated by Sephadex G-200 chromatography and SDS-PAGE, respectively, suggesting that the enzyme is a heteromultimeric protein composed of two types of subunits. On the other hand, the enzyme appeared to be not a glycoprotein according to the results of Con A chromatography and glycoprotein staining. The enzyme had a Km for sucrose of 19.7 mM at pH 7.0 and maximum activity around pH 7.5. The enzyme was most active with sucrose as substrate, compared to raffinose, cellobiose, maltose and lactose. These results indicate the alkaline invertase is a $\beta$-fructofuranosidase.

• Biomolecules & Therapeutics
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• 제24권2호
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• pp.199-205
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• 2016

This study aimed to investigate the in vivo relevance of P-glycoprotein (P-gp) in the pharmacokinetics and adverse effect of phenformin. To investigate the involvement of P-gp in the transport of phenformin, a bi-directional transport of phenformin was carried out in LLC-PK1 cells overexpressing P-gp, LLC-PK1-Pgp. Basal to apical transport of phenformin was 3.9-fold greater than apical to basal transport and became saturated with increasing phenformin concentration ($2-75{\mu}M$) in LLC-PK1-Pgp, suggesting the involvement of P-gp in phenformin transport. Intrinsic clearance mediated by P-gp was $1.9{\mu}L/min$ while passive diffusion clearance was $0.31{\mu}L/min$. Thus, P-gp contributed more to phenformin transport than passive diffusion. To investigate the contribution of P-gp on the pharmacokinetics and adverse effect of phenformin, the effects of verapamil, a P-gp inhibitor, on the pharmacokinetics of phenformin were also examined in rats. The plasma concentrations of phenformin were increased following oral administration of phenformin and intravenous verapamil infusion compared with those administerd phenformin alone. Pharmacokinetic parameters such as $C_{max}$ and AUC of phenformin increased and CL/F and Vss/F decreased as a consequence of verapamil treatment. These results suggested that P-gp blockade by verapamil may decrease the phenformin disposition and increase plasma phenformin concentrations. P-gp inhibition by verapamil treatment also increased plasma lactate concentration, which is a crucial adverse event of phenformin. In conclusion, P-gp may play an important role in phenformin transport process and, therefore, contribute to the modulation of pharmacokinetics of phenformin and onset of plasma lactate level.

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.788-794
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• 2013

Mastitis set apart as clinical and sub clinical is a disease complex of dairy cattle, with sub clinical being the most important economically. Of late, laboratories showed interest in developing biochemical markers to diagnose sub clinical mastitis (SCM) in herds. Many workers reported noteworthy alternation of acute phase proteins (APPs) and nitric oxide, (measured as nitrate+nitrite = NOx) in milk due to intra-mammary inflammation. But, the literature on validation of these parameters as indicators of SCM, particularly in riverine milch buffalo (Bubalus bubalis) milk is inadequate. Hence, the present study focused on comparing several APPs viz. ${\alpha}_1$-anti trypsin, ${\alpha}_1$-acid glycoprotein, fibrinogen and NOx as indicators of SCM in buffalo milk. These components in milk were estimated using standardized analytical protocols. Somatic cell count (SCC) was done microscopically. Microbial culture was done on 5% ovine blood agar. Of the 776 buffaloes (3,096 quarters) sampled, only 347 buffaloes comprising 496 quarters were found positive for SCM i.e. milk culture showed growth in blood agar with $SCC{\geq}2{\times}10^5$ cells/ml of milk. The cultural examination revealed Gram positive bacteria as the most prevalent etiological agent. It was observed that ${\alpha}_1$-anti trypsin and NOx had a highly significant (p<0.01) increase in SCM milk, whereas, the increase of ${\alpha}_1$-acid glycoprotein in infected milk was significant (p<0.05). Fibrinogen was below detection level in both healthy and SCM milk. The percent sensitivity, specificity and accuracy, predictive values and likelihood ratios were calculated taking bacterial culture examination and $SCC{\geq}2{\times}10^5$ cells/ml of milk as the benchmark. Udder profile correlation coefficient was also used. Allowing for statistical and epidemiological analysis, it was concluded that ${\alpha}_1$-anti trypsin indicates SCM irrespective of etiology, whereas ${\alpha}_1$-acid glycoprotein better diagnosed SCM caused by gram positive bacteria. NOx did not prove to be a good indicator of SCM. It is recommended measuring both ${\alpha}_1$-anti trypsin and ${\alpha}_1$-acid glycoprotein in milk to diagnose SCM in buffalo irrespective of etiology.

• 분석과학
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• 제33권4호
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• pp.177-185
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• 2020

Human milk (HM) glycoproteins play important roles protecting infants against various pathogens. Recently, freezing HM is reported to affect some glycoproteins and freeze-drying is suggested as an alternative method. However, the effects of freeze-drying on HM glycoproteins were not evaluated yet. Six fresh HM samples were collected from three healthy mothers at 15 and 60th days of lactation from each mother. Each sample was divided into frozen and freeze-dried subgroups yielding totally 12 samples, and the glycoproteomic analysis was performed by liquid chromatography mass spectrometry. The results were compared between samples of 15 and 60th days of lactation, and before and after the freeze-drying. Totally, 203 glycoproteins were detected. The glycoprotein levels were not different between two groups of 15/60th day of lactation and before/after freeze-drying groups (P > 0.050). In addition, significant correlation of glycoprotein levels was found between the different lactation stages (r = 0.897, P < 0.001) and the status of freeze-drying (r = 0.887, P < 0.001) in a partial correlation analysis. As no significant change of HM glycoproteins was not found after the freeze-drying, we hope that introducing freeze-drying to HM banks is supported by the present study. This work was supported by the National Research Foundation (NRF) of Korea grant funded by the Korea government (MSIP) (No.2017R1D1A1B03034270; No.2020R1A2C1005082).