We have examined the expression of P-glycoprotein (P-gp) in adult T-cell leukemia (ATL) samples from 25 patients. Based on immunoblotting with a monoclonal antibody against P-gp, C219, 8 of 20 ATL patients were P-gp positive at the initial presentation. All 6 patients at the relapsed stage were P-gp positive, and refractory to chemotherapy. The expression of MDR1 mRNA in P-gp-positive ATL cells...

P-glycoprotein (P-gp) can actively pump paclitaxel (PTX) out of cells and induces drug resistance. Abraxane, a nanoparticle (NP) formulation of PTX, has multiple clinical advantages over the single molecule form. However, it is still unclear whether Abraxane overcomes the common small molecule drug resistance problem mediated by P-gp. Here we were able to establish an Abraxane-resistant cell li...

Abstract Background Paclitaxel (PTX) has been suggested to be a promising front-line drug for gastric cancer (GC), while P-glycoprotein (P-gp) could lead resistance by pumping PTX out of GC cells. Consequently, it might hopeful way combat inhibiting the out-pumping function P-gp. Results In this study, we developed delivery system incorporating onto polyethylene glycol (PEG)-modified and oxidiz...

Recent studies showed that P-glycoprotein (P-gp) increases the portal bioavailability (FG) of loperamide by sparing its intestinal first-pass metabolism. Loperamide is a drug whose oral absorption is strongly attenuated by intestinal P-gp-mediated efflux and first-pass metabolism by cytochrome P450 3A (CYP3A). Here the effect of the interplay of P-gp and Cyp3a in modulating intestinal first-pas...

there is a great concern about the effect of propoxur, as one of the more common n-methyl carbamate pesticides, on human health due to its extensive use in agricultural and non-agricultural applications. caco-2 cells became resistant to propoxur, and the resistance was confirmed through mtt assay. then the cell membrane integrity and p-glycoprotein expression were measured by ldh assay and west...

In vitro evaluation of P-glycoprotein (P-gp) inhibitory potential is now a regulatory issue during drug development, in order to predict clinical inhibition of P-gp and subsequent drug-drug interactions. Assays for this purpose, commonly based on P-gp-expressing cell lines and digoxin as a reference P-gp substrate probe, unfortunately exhibit high variability, raising thus the question of devel...

objective(s):transporters have an important role in pharmacokinetics of drugs. inhibition or induction of drug transporters activity can affect drug absorption, safety, and efficacy. p-glycoprotein (p-gp) is the most important membrane transporter that is responsible for active efflux of drugs. it is important to understand which drugs are substrates, inhibitors, or inducers of p-gp to minimize...

The drug efflux pump P-glycoprotein (P-gp) has been shown to promote multidrug resistance (MDR) in tumors as well as to influence ADME properties of drug candidates. Here we synthesized and tested a series of benzophenone derivatives structurally analogous to propafenone-type inhibitors of P-gp. Some of the compounds showed ligand efficiency and lipophilic efficiency (LipE) values in the range ...

BACKGROUND Overexpression of ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) or breast cancer resistance protein (BCRP) accounts for majority of cases of multidrug resistance (MDR) of cancer cells. MATERIALS AND METHODS In the present work, the interactions of seven commercially available phenothiazine derivatives, known ...