Optical properties of fluorescein-labeled organoclay.

We report the preparation of aminopropyl-functionalized magnesium phyllosilicate (Mg-organoclay) conjugated to fluorescein isothiocyanate (FITC) functionality (FITC-organoclay) by one-pot sol-gel synthesis. The physical characteristics of the Mg- and FITC-organoclays were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), FT-IR and UV-Vis spectrophotometry. X-ray fluorescence and elemental analysis were conducted to confirm the composition of the Mg-organoclay.

Evaluation of the flavonoid oroxylin A as an inhibitor of P-glycoprotein-mediated cellular efflux.

Oroxylin A (1), a flavonoid from the roots of Scutellaria baicalensis, increased the cellular accumulation of calcein AM in a concentration-dependent manner in NCI/ADR-RES cells overexpressing P-glycoprotein over the concentration range 0-40 microM. In addition, 1 significantly (p < 0.05) increased the cellular accumulation of paclitaxel in NCI/ADR-RES cells while it did not alter the cellular accumulation of paclitaxel in cells lacking P-glycoprotein expression.

C-myc amplification altered the gene expression of ABC- and SLC-transporters in human breast epithelial cells.

The present study aimed to investigate the effect of c-Myc overexpression on the gene expression and functional activity of major drug transporters in breast epithelial cells. In order to reflect c-Myc overexpressed epithelial cells, MCF10A cells (human mammary epithelial cells) stably expressing c-Myc (c-Myc-MCF10A cells) have been established by retroviral infection and then the effect of c-Myc activation on the gene expression and functional activity of 16 influx and efflux transporters was examined in c-Myc-MCF10A cells. In RT-PCR analysis, the quantitative difference in transporters' gene expression profiles was observed after c-Myc activation.