RESUMEN
OBJECTIVE: To develop an HPLC method for the determination of arctigenin in rat plasma and study the pharmacokinetics of arctigenin nanoemulsion. METHODS: The plasma samples were extracted by ethyl acetate. The determination was carried out on an Agilent C18 column (4.6 mm × 250 mm, 5 μm) with the mobile phase consisting of methanol-0.2% phosphoric acid (52:48, V/V) and the UV detection wavelength was set at 280 nm. Quercetin was selected as internal standard. Arctigenin nanoemulsion was administered to rats by intravenous injection at a dose of 4 mg · kg-1. The plasma concentration of arctigenin at different time points was determined by the established HPLC method. The pharmacokinetic parameters were processed by DAS2.1 software. RESULTS: The calibration curve of arctigenin had acceptable linearity in the range of 0.1-10 mg · L-1 in rat plasma(r=0.9992). The lower limit of quantitation (LLOQ) was estimated to be 0.1 mg · L-1 and the lower limit of detection (LLOD) was estimated to be 0.03 mg · L-1. The mean extraction recovery rates of arctigenin QC samples at low, medium and high concentration levels were all a-bove 85%. The intra-day and inter-day precisions were less than 6%. The pharmacokinetics of arctigenin in rats after intravenous injection were fitted to a two-compartment model and the half-lives of α phase and β phase were (0.134 ± 0.085) and (1.471 ± 0.164) h, respectively. CONCLUSION: The HPLC method is simple, rapid and accurate. It can be used for monitoring the plasma concentration of arctigenin and its pharmacokinetic study. After intravenous administration of arctigenin nanoemulsion, arctigenin is rapidly distributed into tissues, but the elimination is slow.
RESUMEN
In order to study the important factors involved in cationic liposome-mediated gene transfer, Lipofectamine 2000 or DOTAP was evaluated using three types of cells (Hep-2, MCF-7 and SW-480) in vitro transfection efficiencies. Different properties of the two reagents were analyzed and compared by DNA arrearage assay and MTT assay. Both Lipofectamine 2000 and DOTAP had strong capability to combine with DNA; Lipofectamine 2000 can get higher transfection efficiency of the three cells by using GFP as report gene, meanwhile, DOTAP can also get higher transfection efficiency against Hep-2 cell. However, DOTAP showed lower transfection efficiency against MCF-7 and SW-480 cell. On the other hand, the cytotoxicity assay showed that over 85% cell viability of MCF-7 cell could be achieved both by Lipofectamine 2000 and DOTAP under the optimal transfection condition. Relatively speaking, Lipofectamine 2000 has very high transfection efficiency in a broad range of cell lines, but because of the special selectivity of cell type on liposome, DOTAP also has a broad application prospect.