Pharmacokinetic and tissue distribution analysis of bioactive compounds from Fuke Qianjin capsules in rats by a validated UPLCMS/MS method.

Fuke Qianjin capsules (FKQJ) exhibit obvious advantages and characteristics in the treatment of pelvic inflammatory disease. At present, information regarding the in vivo process of FKQJ is lacking, which has become a bottleneck in further determining the therapeutic effect of this traditional Chinese medicine. In the present study, a sensitive, simple and reliable method was developed and validated for the simultaneous quantification of 12 main components (4 flavonoids, 4 alkaloids, 2 phthalides and 2 diterpene lactones) in plasma and seven tissues of rats to study the pharmacokinetic and distribution characteristics of these components in vivo by using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the first time. Plasma and tissue were prepared by protein precipitation with acetonitrile and methanol, followed by its separation on a Waters Acquity UPLC BEH C18 column. The quantification was performed via multiple reaction monitoring (MRM) by a triple quadrupole mass spectrometer under positive electrospray ionization (ESI) mode. The method was validated to demonstrate its selectivity, linearity, accuracy, precision, recovery, matrix effect and stability. For 12 analytes, the low limit of quantification (LLOQs) reached 0.005-2.44 ng/mL, and all calibration curves showed good linearity (r2 ≥ 0.990) in linear ranges. The intra-day and inter-day precision (relative standard deviation) for all analytes was less than 14.96%, and the accuracies were in the range of 85.29%-114.97%. Extraction recoveries and matrix effects of analytes were acceptable. The pharmacokinetic results showed that the main components could be absorbed quickly, had a short residence time, and were eliminated quickly in vivo. At different time points, the 12 components were widely distributed with uneven characteristics in the body, which tended to be distributed in the liver, kidney and lung and to a lesser extent in the uterus, brain and heart. The pharmacokinetic process and tissue distribution characteristics of FKQJ were expounded in this study, which can provide a scientific theory for in-depth development of FKQJ and guide FKQJ use in the clinic.

An Annexin V-based biosensor for quantitatively detecting early apoptotic cells.

In this paper, we reported that a novel biosensor was developed to detect early apoptotic cells by the specific interaction between Annexin V and phosphatidylserine based on electrochemical impedance. Annexin V was immobilized on a self-assembled layer of gold nanoparticles, which allowed stable and high loading of Annexin V on the electrode surface, offering the possibility of sensitivity enhancement. Early apoptotic cells showed an increased exposition of phosphatidylserine on the cell membrane caused by physiological and pathological response reaction, leading to a strong interaction between the apoptotic cells and the electrode surface, which could be probed by electrochemical impedance spectroscopy. As examined using a model system of cells integrated by phosphatidylserine-modified liposome and a real one of early apoptotic cell induced by 5-fluorouracil, this biosensor demonstrated the great potential for rapid detection of cell apoptosis and drug screening. The results agreed well with those obtained using fluorescence microscopy and flow cytometry.