• Natural Product Sciences
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• 제20권1호
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• pp.1-6
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• 2014

P-glycoprotein (P-gp) is a permeability glycoprotein also known as multidrug resistance protein 1 (MDR1). P-gp is an ATP-binding cassette (ABC) transporter that pumps various types of drugs out of cells. These transporters reduce the intracellular concentrations of drugs and disturb drug absorption. The Caco-2 cell permeability assay system is an effective in vitro system that predicts the intestinal absorption of drugs and the functions of enzymes and transporters. Rhodamine-123 (R-123) and digoxin are well-known P-gp substrates that have been used to determine the function of P-gp. Efflux of P-gp substrates by P-gp has been routinely evaluated. To date, a number of herbal medicines have been tested with Caco-2 cell permeability assay system to assess bioavailability. There are growing efforts to find phytochemicals that potentially regulate P-gp function. The Caco-2 cell permeability assay system is a primary strategy to search for candidates of P-gp inhibitors. In this mini review, we have summarized the P-gp modulation by herbal extracts, decoctions or single components from natural products using Caco-2 cell permeability assays. Many natural products are known to regulate P-gp and herbal medicines could be used in combination with conventional drugs to enhance bioavailability.

• Journal of the Korean Wood Science and Technology
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• 제32권5호
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• pp.51-58
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• 2004

본 연구에서는 능이가 포함하고 있는 각종 생리활성 성분올 분석하고, 열수추출-에틸알코올 침전에 의하여 분리한 glycoprotein 의 특성을 구명코자 하였다. 능이(Sarcodon aspratus)의 무기성분 및 아미노산의 조성을 분석하였는 바, 능이는 Ca, Mg, Zn, Mn, Fe, Cu 및 Ph를 함유하였으며, 특히 Ca 및 Na 성분이 많이 함유되어 있었다. 유리 및 총 아미노산을 분석한 결과, 14종의 유리아미노산이 검출되었고. glutamic acid, alanine, arginine 등이 많았다. 총아미노산은 15종이었으며, glutamic acid가 가장 많았고, aspartic acid, serine, threonine 등이 그 다음이었다. 열수-95% 에틸알코올 추출에 의하여 70.6%의 당과 3.32%의 glycoprotein을 얻었으며, 에틸알코올의 농도에 따라 당의 함량이 상이한 glycoprotein을 얻을 수 있었는데, 에틸알코올의 농도가 30~70%로 낮은 경우, 당함량이 92% 이상으로 매우 높았다. 조 glycoprotein (GP). 분자량 30만 이상의 분획(P), P분획 가운데 DEAE-Sephadex에 흡착되지 않는 분획(P-1), P-1을 다시 Sepharose 2B로 젤여과하여 얻은 부분(P-2), DEAE-Sephadex에 흡착되는 부분 (P-3) 등으로 분획한 결과, 정제과정에서 total sugar의 함량은 점차 증가하였으며, 단백질의 함량은 점차 감소되는 것으로 나타났다. 단당류의 조성을 분석한 결과, GP 빛 P-3 에서 glucose, galactose, mannose, fucose 등 4종의 당이 검출 되었으며, GP에는 glucose 가 거의 대부분을 이루고 있었고, glutamic acid, serine, alanine, glycine 등이 고농도로 함유되어 있었다. P-3에는 mannose 및 aspartic acid, glutamic acid, glycine 등의 아미노산이 함유되어 있었다. P-2에서는 glucose가 많았고, 다른 fraction에는 없었던 fucose의 함량이 높았으며 mannose는 검출되지 않았다. 한편 아미노산조성은 조 glycoprotein (GP)에는 glutamic acid, serine, alanine, glycine 등이 고농도로 함유되었으며, P-3분획에서는 aspartic acid, glutamic acid, glycine 등이 함유되어 있었다. 한편 P-2 fraction의 경우는 단백질함량이 1.1%로서 매우 낮았으며, 분자량은 700,000 이상이었다. aspartic acid, glutamic acid, alanine이 비교적 다량 함유되었으며, mannose 및 cysteine은 거의 확인되지 않았다.

• 한국환경과학회지
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• 제28권2호
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• pp.249-257
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• 2019

Ulmus davidiana Nakai (UDN) has been traditionally used as a herbal medicine to treat inflammatory diseases in Korea. In the present study, we investigated the anti-ecotoxic potential of a 116 kDa glycoprotein isolated from UDN (UDN glycoprotein) in human intestinal epithelial INT-407 cells. We demonstrated that UDN glycoprotein ($20{\mu}g/mL$) could inhibit the production of lactate dehydrogenase (LDH) induced by toluene, an ecotoxic substance. Additionally, we found that the toluene-induced intestinal cytotoxicity was mediated by the phosphorylation of p38 Mitogen-Activated Protein Kinase (MAPK) via the production of intracellular Reactive Oxygen Species (ROS). The UDN glycoprotein significantly decreased the levels of ROS production and p38 MAPK activation in toluene-stimulated INT-407 cells. Moreover, the UDN glycoprotein inhibits the phosphorylation of nuclear factor-kappa B ($NF-{\kappa}B$), which is responsible for the production of LDH, in toluene-stimulated INT-407 cells. Collectively, our data indicate that UDN glycoprotein is a natural antioxidant and a modulator of ecotoxicity signaling pathways in human intestinal epithelial cells.

• Journal of Veterinary Science
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• 제22권5호
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• pp.61.1-61.13
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• 2021

Background: Hepatocellular carcinoma is the most common primary hepatic malignancy in humans and dogs. Several differentially expressed molecules have been studied and reported in human hepatocellular carcinoma and non-neoplastic liver lesions. However, studies on the features of canine hepatocellular carcinoma are limited, especially related to the differential characteristics of neoplastic and non-neoplastic lesions. Objectives: The study's objective was 1) to examine and evaluate the expression of arginase-1, P-glycoprotein, and cytokeratin 19 in canine liver tissues and 2) to investigate the differential features of hepatocellular carcinomas, liver tissue with non-neoplastic lesions, and paracancerous liver tissues in dogs. Methods: The expression levels of three markers underwent immunohistochemical analysis in 40 non-neoplastic liver tissues, 32 hepatocellular carcinoma tissues, and 11 paracancerous liver tissues. Scoring of each marker was performed semi-quantitatively. Results: Arginase-1 and P-glycoprotein were significantly downregulated in hepatocellular carcinoma, compared with hepatic tissues with non-neoplastic diseases (p < 0.001). Expression levels of arginase-1 and P-glycoprotein were also significantly lower in hepatocellular carcinoma than in paracancerous liver tissues (arginase-1, p = 0.0195; P-glycoprotein, p = 0.047). Few cytokeratin 19-positive hepatocytes were detected and only in one hepatocellular carcinoma and one cirrhotic liver sample. Conclusions: The results of this study suggest that downregulation of arginase-1 and P-glycoprotein is a feature of canine hepatocellular carcinoma; thus, those markers are potential candidates for use in differentiating hepatocellular carcinomas from non-neoplastic liver lesions in dogs.

• 약학회지
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• 제48권4호
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• pp.226-230
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• 2004

The pharmacokinetics of orally administered paclitlxel (50 mg/kg) was studied in six rabbits after 1hr pretreatment (2.0 mg/kg and 10 mg/kg) of tetramethoxyflavone or coadministration of (2.0 mg/kg, 10 mg/kg and 20 mg/kg) tetramethoxyflavone. The area under the plasma concentration-tine curve (AUC) and plasma concentration of paclitaxe1 coadministered with tetramethoxyflavone (10 mglkg) were increased significantly (p<0.05) compared with control. However, coadministration of tetramethoxyflavone (2 and 20 mg/kg) showed no significant effect on the pharmacokinetic parameters of paclitaxel. Pretreatment with tetramethoxyflavone significantly (p<0.05) increased the plasma concentration of paclitaxel. The area under the plasma concentration-time curve (AUC) and the peak concentration (C$_{max}$) of paclitaxel pretreated with tetramethoxyflavone were increased significantly (p<0.01, p<0.05) compared with control. The terminal half. life of paclitaxel pretreated with tetramethoxyflavone (2 mg/kg and 10 mg/kg) was significantly (p<0.05) prolonged compared with control. Pretreatment with tetramethoxyflavone (2.0 mg/kg, 10 mg/kg) significantly (p<0.01, p<0.05) increased the absolute bioavailability of paclitaxel compared with the control (154∼179%). On the basis of the results, it might be considered that tetramethoxyflavone may inhibit cytochrome P450 or P-glycoprotein efflux pump which are engaged in paclitaxel metabolism, result in increased AUC and t$_{1}$2/ of paclitaxel. However, further study should be conducted to clarify the roles of cytochrome P450 and P-glycoprotein on paclitaxel bioavailability with/or without tetramethoxyflavone. P-glycoprotein on paclitaxel bioavailability with/or without tetramethoxyflavone.

• Journal of Microbiology
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• 제34권1호
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• pp.7-14
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• 1996

Teh baculovirus gp64 glycoprotein is a major component of the envelope of budded virus (BV) and has been shown that it plays an essential role in the infection process, especially virus-cell membrane fusion. We have cloned Autographa californica Nuclear Polyhedrosis Virus (AcNPV) gp64 protein were examined for membrane fusion activity by using a synchtium formation assay under various conditions. The optimal conditions required for inducing membrane fusion are 1) form pH 4.0 to 4.8 2) 15 min exposure of cells to acidic pH 3) at least 1 .mu.g of gp64 cloned plasmid DNA per 3 * 10$^{6}$ cells 4) and an exposure of cells to acidic pH at 72 h post-transfection. In order to investigate the role of hydrophobicity of the gp64 glycoprotein for the membrane fusion, the two leucine residues (amino acid position at 229 and 230) within hydrophobic region I were substituted to alanine by PCR-derived site-directed mutagenisis and the membrane fusion activity of the mutant was anlaysed. The gp64 glycoprotein carrying double alamine substitution mutation showed no significant difference in fusion activity. This result suggested that minor changes in hydrophobicity at the amino acid position 229 and 230 does not affect the acid-induced membrane fusion activity of the gp64 glycoprotein.

• 한국해양바이오학회지
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• 제1권3호
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• pp.213-217
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• 2006

본 연구는 황백에 함유되어 있는 주요 화합물인 berberine, palmatine, limonin 및 rutaecarpine의 CYP2D6 및 p-glycoprotein 활성에 대한 저해정도를 탐색함으로써, 황백을 다른 양약과 병용시 약물상호작용을 유발할 수 있는 가능성을 평가하고자 하였다. 인체 간 마이크로좀 시료에 CYP2D6 동효소의 기질약물인 dextromethorphan과 NADPH 재생성계 및 저해제 ($200{\mu}M$)를 첨가한 후 반응시켜 생성된 대사물을 LC/MS/MS를 이용하여 정량하여 CYP2D6 동효소 활성의 변화를 평가하였다. 또한 약물수송단백인 p-glycoprotein의 활성은 L-MDR1 세포주를 이용한 calcein AM 축적 실험을 통하여 평가하였다. 그 결과 식물 알카로이드인 berberine에서 강력한 CYP2D6 활성 저해능을 관찰하였으며, 저해 효과는 농도 의존적으로 증가하였으며, mechanism-based 저해 기전을 나타내었다. 그러나 limonine과 rutaecarpine은 CYP2D6 저해 활성을 보이지 않았고, p-glycoprotein 기능에 대해서는 평가한 어떤 화합물도 저해 활성을 나타내지 않았다. 황백의 주요 성분인 berberine의 CYP2D6 활성 저해능을 고려할 때, 황백을 CYP2D6 기질약제와 병용시 약물상호작용을 유발할 가능성을 보여준다. 이러한 황백의 CYP2D6를 매개로한 임상적인 약물상호작용 가능성은 임상시험을 통하여 추가적인 검정이 필요할 것으로 사료된다.

• 한국임상약학회지
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• 제23권3호
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• pp.206-212
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• 2013

Purpose: The aim of this study was to investigate the effect of nimodipine on the pharmacokinetics of warfarin after oral and intravenous administration of warfarin in rats. Methods: Warfarin was administered orally (0.2 mg/kg) or intravenously (0.05 mg/kg) without or with oral administration of nimodipine (0.5 or 2 mg/kg) in rats. The effect of nimodipine on the P-glycoprotein as well as cytochrome P450 (CYP) 3A4 activity was also evaluated. Results: Nimodipine inhibited CYP3A4 enzyme activity with 50% inhibition concentration ($IC_{50}$) of $10.2{\mu}M$. Compared to those animals in the oral control group (warfarin without nimodipine), the area under the plasma concentration-time curve (AUC) of warfarin was significantly greater (0.5 mg/kg, P<0.05; 2 mg/kg, P<0.01) by 31.3-57.6%, and the peak plasma concentration ($C_{max}$) was significantly higher (2 mg/kg, P<0.05) by 29.4% after oral administration of warfarin with nimodipine, respectively. Consequently, the relative bioavailability of warfarin increased by 1.31- to 1.58-fold and the absolute bioavailability of warfarin with nimodipine was significantly greater by 64.1-76.9% compared to that in the control group (48.7%). In contrast, nimodipine had no effect on any pharmacokinetic parameters of warfarin given intravenously. Conclusion: Therefore, the enhanced oral bioavailability of warfarin may be due to inhibition of CYP 3A4-mediated metabolism rather than P-glycoprotein-mediated efflux by nimodipine.

• 한국식품과학회지
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• 제41권4호
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• pp.405-412
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• 2009

본 연구는 꾸지뽕 나무 열매로부터 75 kDa의 당단백질(꾸지뽕 당단백질)을 추출한 후 꾸지뽕 당단백질의 첨가에 따른 알레르기성 염증 인자인 histamine 유리 억제능력 및 COX-2의 활성 억제 효과를 평가하였다. RBL-2H3세포를 22시간 동안 IgE로 감작시킨 후, HSA를 처리하여 histamine의 유리양을 측정한 결과 꾸지뽕 당단백질을 처리한 농도가 증가함에 따라 histamine의 유리와 COX-2의 활성 억제율은 증가하였다. 또한 꾸지뽕 당단백질의 처리는 HSA에 의해 유도된 세포내 ROS 생성량을 농도에 의존적으로 억제하였다. 한편 꾸지뽕 당단백질을 농도별로 처리하여 세포내 단백질을 추출하여 western blot을 실시한 결과 100 ${\mu}g$/mL 농도의 꾸지뽕 당단백질을 처리한 그룹에서 ERK1/2, AP-1과 COX-2의 활성 수준은 현저히 억제 되었다(p<0.05). 따라서 이러 한 결과에 미루어볼 때, 꾸지뽕 당단백질은 세포내 해독효소의 활성을 증가시킴으로써 ROS 수준을 감소시켰으므로 꾸지뽕 당단백질의 역할이 다른 천연물 유래의 당단백질과 마찬가지로 특이적인 항산화 능력을 지니고 있음을 나타내며 histamine의 유리 억제와 COX-2의 활성이 억제되었을 것으로 생각된다. 이는 꾸지뽕 당단백질이 항 알레르기 효능을 갖는 물질로써 알레르기성 비염, 아토피 등과 같은 알레르기 관련 질환의 예방 및 치료제로 사용될 수 있을 것 사료된다.

• Archives of Pharmacal Research
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• 제27권2호
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• pp.127-135
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• 2004

Multiple drug administration is common in elderly, HIV, and cancer patients. Such treatments may result in drug-drug interactions due to interference at the metabolic enzyme level, and due to modulation of transporter protein functions. Both kinds of interference may result in altered drug distribution and toxicity in the human body. In this review, we have dealt with drug-drug interactions related to the most studied human transporter, P-glycoprotein. This transporter is constitutively expressed in several sites in the human body. Its function can be studied in vitro with different cell lines expressing P-glycoprotein in experiments using methods and equipment such as flow cytometry, cell proliferation, cell-free ATP as activity determination and Transwell culture equipment. In vivo experiments can be carried out by mdr1a(-/-) animals and by noninvasive methods such as NMR spectrometry. Some examples are also given for determination of possible drug-drug interactions using the above-mentioned cell lines and methods. Such preclinical studies may influence decisions concerning the fate of new drug candidates and their possible dosages. Some examples of toxicities obtained in clinics and summarized in this review indicate careful consideration in cases of polypharmacy and the requirement of preclinical studies in drug development activities.