Relationship between the inhibition of azidopine binding to P-glycoprotein by MDR modulators and their efficiency in restoring doxorubicin intracellular accumulation

1996 ◽  
Vol 109 (1-2) ◽  
pp. 203-209 ◽  
Author(s):  
Yan-Ping Hu ◽  
Christiane Chapey ◽  
Jacques Robert
Keyword(s):  
Intracellular Accumulation ◽  
P Glycoprotein

scholarly journals Intracellular accumulation of efavirenz and nevirapine is independent of P-glycoprotein activity in cultured CD4 T cells and primary human lymphocytes

2009 ◽  
Vol 64 (5) ◽  
pp. 1002-1007 ◽  
Author(s):  
O. Janneh ◽  
B. Chandler ◽  
R. Hartkoorn ◽  
W. S. Kwan ◽  
C. Jenkinson ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Human Lymphocytes ◽  
Intracellular Accumulation ◽  
P Glycoprotein

Reversal of P-glycoprotein-medicated multidrug resistance by LBM-A5 in vitro and a study of its pharmacokinetics in vivo

2015 ◽  
Vol 93 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Tianxiao Zhao ◽  
Yun Song ◽  
Baomin Liu ◽  
Qianqian Qiu ◽  
Lei Jiao ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Cancer Chemotherapy ◽  
Anticancer Agents ◽  
Efflux Pump ◽  
Therapeutic Index ◽  
Intracellular Accumulation ◽  
P Glycoprotein ◽  
Reversal Mechanism

The overexpression of P-glycoprotein (P-gp) in tumors leads to multidrug resistance (MDR), which is a significant obstacle in clinical cancer chemotherapy. The co-administration of anticancer drugs and MDR modulators is a promising strategy for overcoming this problem. Our study aimed to explore the reversal mechanism and safety of the MDR modulator LBM-A5 in vitro, and evaluate its pharmacokinetics and effects on doxorubicin metabolism in vivo. We evaluated an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay of anticancer agents mediated by LBM-A5, the effect of LBM-A5 on rhodamine123 intracellular accumulation, and the efflux in K562/DOX cells to investigate the reversal mechanisms of LBM-A5. The results showed that LBM-A5 inhibits rhodamine123 efflux and increases intracellular accumulation by inhibiting the efflux pump function of P-gp. Furthermore, the therapeutic index and CYP3A4 activity analysis in vitro suggested that LBM-A5 is reasonably safe to use. Also, LBM-A5 (10 mg/kg body mass) achieved the required plasma concentration in sufficient time to reverse MDR in vivo. Importantly, the LBM-A5 treatment group shared similar doxorubicin (DOX) pharmacokinetics with the free DOX group. Our results suggest that LBM-A5 effectively reverses MDR (EC50 = 483.6 ± 81.7 nmol·L−1) by inhibiting the function of P-gp, with relatively ideal pharmacokinetics and in a safe manner, and so may be a promising candidate for cancer chemotherapy research.

scholarly journals Cellular Accumulation and Pharmacodynamic Evaluation of the Intracellular Activity of CEM-101, a Novel Fluoroketolide, against Staphylococcus aureus, Listeria monocytogenes, and Legionella pneumophila in Human THP-1 Macrophages

2009 ◽  
Vol 53 (9) ◽  
pp. 3734-3743 ◽  
Author(s):  
Sandrine Lemaire ◽  
Françoise Van Bambeke ◽  
Paul M. Tulkens
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Legionella Pneumophila ◽  
Critical Role ◽  
Intracellular Accumulation ◽  
Cellular Accumulation ◽  
Intracellular Activity ◽  
P Glycoprotein

ABSTRACT CEM-101 is a novel fluoroketolide with lower MICs than those of telithromycin and macrolides. Our aim was to assess the cellular accumulation and intracellular activity of CEM-101 using models developed for analyzing the pharmacokinetics and pharmacological properties of antibiotics against phagocytized bacteria. We used THP-1 macrophages and Staphylococcus aureus (ATCC 25923 [methicillin (meticillin) sensitive]), Listeria monocytogenes (strain EGD), and Legionella pneumophila (ATCC 33153). CEM-101 reached cellular-to-extracellular-concentration ratios of about 350 within 24 h (versus approximately 20, 30, and 160 for telithromycin, clarithromycin, and azithromycin, respectively). This intracellular accumulation was suppressed by incubation at a pH of ≤6 and by monensin (proton ionophore) and was unaffected by verapamil (P-glycoprotein inhibitor; twofold accumulation increase for azithromycin) or gemfibrozil. While keeping with the general properties of the macrolide antibiotics in terms of maximal efficacy (E max; approximately 1-log10-CFU decrease compared to the postphagocytosis inoculum after a 24-h incubation), CEM-101 showed significantly greater potency against phagocytized S. aureus than telithromycin, clarithromycin, and azithromycin (for which the 50% effective concentration [EC50] and static concentrations were about 3-, 6-, and 15-fold lower, respectively). CEM-101 was also about 50-fold and 100-fold more potent than azithromycin against phagocytized L. monocytogenes and L. pneumophila, respectively. These differences in EC50s and static concentrations between drugs were minimized when data were expressed as multiples of the MIC, demonstrating the critical role of intrinsic drug activity (MIC) in eliciting the antibacterial intracellular effects, whereas accumulation per se was unimportant. CEM-101 should show enhanced in vivo potency if used at doses similar to those of the comparators tested here.

Reversal of P-Glycoprotein-Dependent Resistance to Adriamycin by 5-bromotetrandrine in K562/A02 Cell Line.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4175-4175
Author(s):  
Bao-An Chen ◽  
Jue-Qiong Wang ◽  
Jia-Hua Ding ◽  
Feng Gao ◽  
Jian Chen ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
K562 Cells ◽  
Control Group ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Intracellular Accumulation ◽  
Protein Levels ◽  
P Glycoprotein ◽  
Mdr Reversal

Abstract Objective: The present study aimed to evaluate the MDR reversal activity of bromotetrandrine (BrTet), a bromized derivative of tetrandrine (Tet), in vitro. Methods: Drug sensitivity was determined using the MTT assay. Adriamycin (ADM) accumulation, the protein levels of P-glycoprotein (P-gp) and the apoptotic changes were analyzed by fluorospectrophotometry, respectively. The mRNA levels of P-gp was determined by RT-PCR. Results: BrTet at 0.25, 0.5 and reversed ADM resistance in MDR K562/A02 cells dose-dependently and its potency was greater than that of Tet at the same concentrations. The IC50 of ADM for K562 and K562/A02 cells were 55.122 mg/l and 1.1373 mg/l, respectively. Treating K562/A02 cells with BrTet(1uM)and TTD(1uM)both for 48 hours partially restored the sensitivity of K562/A02 cells to ADM (IC50 were 4.7729 mg/l and 13.584 mg/l respectively) but had not effect on K562 cells. The fold reversal (FR) were 11.55 and 4.06 respectively. K562/A02 cells showed apoptotic characteristics after treated with Brtet and Tet both for 48 hours compared with control group(apoptosis rate was 61.1%, 11.1% and 9.9%,respectively); Fluorospectrophotometric assay showed that BrTet significantly increased the intracellular accumulation of ADM in K562/A02 cells in a dose-dependent manner. The fluorescence intensity of intracellelar ADM in K562/A02 cells treated with ADM(1mg/L)was 33% of that in K562 cells. BrTet and Tet elevated the intracellular ADM concentration in K562/A02 cells up to 52% and 69%,respectively. BrTet also inhibited the overexpression of P-gp in K562/A02 cells. The fluorescence intensity of P-gp in K562 and K562/A02 cells was 0.5 and 97.97.The P-gp expression was down after treated with BrTet and TTD (65.05 and 54.86). The mdr1 mRNA was also down regulated. Conclusions: BrTet showed significant MDR reversal activity in vitro. Its activity may be related to the inhibition of P-gp overexpression and the increase in intracellular accumulation of anticancer drugs. BrTet may be a promising MDR modulator for eventual assessment in the clinic.

scholarly journals Effect of four ABCB1 genetic polymorphisms on the accumulation of darunavir in HEK293 recombinant cell lines

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gabriel Stillemans ◽  
Happy Phanio Djokoto ◽  
Kévin-Alexandre Delongie ◽  
Halima El-Hamdaoui ◽  
Nadtha Panin ◽  
...  
Keyword(s):  
Genetic Polymorphisms ◽  
Cell Lines ◽  
Hek293 Cell ◽  
Hiv Protease ◽  
Activity Levels ◽  
Wild Type ◽  
Intracellular Accumulation ◽  
P Glycoprotein ◽  
Significant Difference ◽  
Recombinant Cell

AbstractThe intracellular penetration of darunavir, a second-generation HIV protease inhibitor, is limited by the activity of the efflux P-glycoprotein (ABCB1). ABCB1 expression and/or activity levels can vary between individuals due to genetic polymorphisms including the c.1199G>A, c.1236C>T, c.2677G>T and c.3435C>T variants, which could in part explain why the pharmacokinetics of darunavir are so variable from one individual to another. While a few clinical studies have failed to demonstrate an influence of these polymorphisms on darunavir pharmacokinetics, drug-drug interactions and methodological limitations may have prevented them from revealing the true influence of ABCB1 variants. In this work, we report on the intracellular accumulation of darunavir in recombinant HEK293 cell lines expressing wild-type ABCB1 or one of several variants: ABCB1 1199A, ABCB1 3435T, and ABCB1 1236T/2677T/3435T. We demonstrate that while ABCB1 expression limits intracellular accumulation of darunavir, there is no significant difference in efflux activity between cells expressing wild-type ABCB1 and those that express any of the studied variants.

scholarly journals Absorption and Metabolism Characteristics of Rutin in Caco-2 Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaofang Zhang ◽  
Jinhui Song ◽  
Xiaopeng Shi ◽  
Shan Miao ◽  
Yan Li ◽  
...  
Keyword(s):  
Apical Membrane ◽  
Multidrug Resistant ◽  
Transmembrane Transport ◽  
Tandem Mass ◽  
Intracellular Accumulation ◽  
P Glycoprotein ◽  
Apical Membranes ◽  
Reliable Analytical Method ◽  
Differential Permeability ◽  
Specific Transport System

The intestinal absorption and metabolism characteristics of the potentially beneficial polyphenol rutin were studied by measuring the intracellular accumulation and transport of rutin into Caco-2 cells with the sensitive and reliable analytical method of HPLC-coupled tandem mass spectrometry. Rutin and glucuronidated rutin were absorbed differently by the basolateral and apical membranes, and rutin showed differential permeability through the apical and basolateral sides. Approximately 33% of the rutin was metabolized to glucuronidated rutin, and the intracellular concentration of glucuronidated rutin was much lower than that of parent rutin. P-glycoprotein and multidrug-resistant proteins 2 and 3 were involved in the transmembrane transport and intracellular accumulation of rutin by Caco-2 cells. These results suggest that a specific transport system mediates rutin movement across the apical membrane in Caco-2 cells and that metabolic enzymes are important for this process.

scholarly journals Synergistic Therapy of Doxorubicin with Cationic Anticancer Peptide L-K6 Reverses Multidrug Resistance in Cancer Cells in vitro via P-glycoprotein Inhibition

2021 ◽  
Author(s):  
Che Wang ◽  
Lili Huang ◽  
Ruojin Li ◽  
Ying Wang ◽  
Xiaoxue Wu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Laser Scanning ◽  
Therapeutic Potential ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Intracellular Accumulation ◽  
Anticancer Peptide ◽  
P Glycoprotein ◽  
Mdr Reversal ◽  
Mcf 7

AbstractMultidrug resistance (MDR) is one of the major obstacles to efficient chemotherapy against cancers, resulting from the overexpression of drug efflux transporters such as P-glycoprotein (P-gP). In the present study, we aimed to evaluate the MDR reversal activity and synergistic therapeutic potential of cationic anticancer peptide L-K6 with doxorubicin (DOX) on P-gP-overexpressing and DOX-resistant MCF-7/Adr human breast cancer cells. Flow cytometry and confocal laser scanning microscopy were used to determine the intracellular accumulation of DOX and another P-gP substrate, Rho123. P-gP-Glo assay, Western blot and Biacore analysis were further performed to evaluate the P-gP function and expression. The cytotoxicity in MCF-7 or MCF-7/Adr cells was measured by MTT assay. Flow cytometry assay and confocal laser scanning microscopy observation clearly revealed an increased intracellular accumulation of DOX and Rho123 in MCF-7/Adr cells treated with L-K6, suggesting a P-gP inhibiting potential. Biacore analysis, P-gP-Glo assay and Western blot further confirmed that L-K6 could directly interact with P-gP, inhibit P-gP function and decrease P-gP expression in MCF-7/Adr cells. In addition, as expected, the data from MTT assay indicated that L-K6 restored the sensitivity of MCF-7/Adr cells to DOX, indicating a MDR reversal potential and a promising synergistic anticancer activity. All these findings may provide experimental evidence to support the promising applications and synergistic therapeutic potential of peptidic P-gP inhibitors against MDR cancer.

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