[Show abstract][Hide abstract] ABSTRACT: The purpose of the present study was to prepare glycyrrhizic acid-phospholipid complex (GL-PLC) as to improve the oral bioavailability of glycyrrhizic acid (GL), enhance the drug efficacy and reduce the side effects. The uniform experimental design approach was utilized for the process optimization in order to obtain the satisfactory complex. The results of comparison between GL-PLC and free GL indicated that the anti-inflammatory activity of the phospholipid complex was significantly higher than that of free GL at the same dose. The results of pharmacokinetic study displayed that the plasma concentration of glycyrrhetic acid, the metabolite of GL in vivo, increased after oral administration of GL-PLC. The C max of GL-PLC was 2.14 times higher than that of free glycyrrhizic acid, while the AUC of GL-PLC was 1.74 times higher than that of free GL. The results proved that GL-PLC improved the lipophilic property of GL, increased the bioavailability and anti-inflammatory activity.
No preview · Article · Oct 2011 · LATIN AMERICAN JOURNAL OF PHARMACY
[Show abstract][Hide abstract] ABSTRACT: The ineffectiveness of anticancer drugs is frequently observed in cancer chemotherapy. The resistance of tumor cells to various cytotoxic drugs is defined as multidrug resistance (MDR). The purpose of our present study was to investigate the inhibitory effects of L1EPO synthesized by our group on P-glycoprotein (P-gp)-mediated MDR in K562/A02 and KBv200 cell lines, which expressed high levels of P-gp. Both the cytotoxicity of the compound and its ability to inhibit K562/A02 and KBv200 cells were determined by sulforhodamine B sodium salt (SRB) assay. Morphologic apoptosis was detected by Hoechst33342 staining assay. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect mdr-1 gene transcription, and Western blot assay was used to assess P-gp expression. Interestingly, we found that the K562/A02 cell line was rendered resistant toward Adriamycin but not towards L1EPO when compared with the parental cells. Furthermore, L1EPO could down-regulate the mdr-1 gene, and it reduced the expression of P-gp and displayed a perfect dose dependence. Moreover, it had less cytotoxicity in normal human cell lines (fibroblast, VEC), GI(50)>10 micromol/l. Consequently, L1EPO has the potential to overcome P-glycoprotein-mediated MDR in the K562/A02 cell line.