The evolution and application progress of non-modified drug target discovery CETSA technology / 药学学报

Understanding the research methods for drug protein targets is crucial for the development of new drugs, clinical applications of drugs, drug mechanisms, and the pathogenesis of diseases. Cellular thermal shift assay (CETSA), a target research method without modification, has been widely used since its development. Now, there are various CETSA-based technology combinations, such as mass spectrometry-based cellular thermal shift assay (MS-CETSA), isothermal dose response-cellular thermal shift assay (ITDR-CETSA), amplified luminescent proximity homogeneous assay-cellular thermal shift assay (Alpha-CETSA), etc., which combine their respective advantages and further expand the application scope of CETSA. These technologies are suitable for the entire drug development chain, from drug screening to monitoring the target binding and off-target toxicity of drugs in patients. Based on the author's research experience, this paper reviews the principles of CETSA and related binding technologies, their application in target discovery, and the progress of data processing and analysis in recent years, aiming to provide reference and reference for the further application of CETSA.

Quantification of (-)doxazosin at very low concentration in rat plasma samples by SPE-LC-MS/MS / 药学学报

Previous publications showed that the value of LLOQ (lowest limit of quantification) for doxazosin and its enantiomers in biological samples were above 0.1 ng·mL-1. The present study was designed to establish a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification at very low concentration of (-)doxazosin in rat plasma after intravenous administration of (-)doxazosin (3.0 mg·kg-1). The plasma samples containing prazosin as an internal standard were extracted by solid-phase extraction (SPE) and separated on Acquity BEH C18(50 mm×2.1 mm, 1.7 μm) column under alkaline conditions of the mobile phase. (-)Doxazosin was monitored under positive ionization condition by multiple reaction monitoring (MRM) with an ESI source. The good linear range of (-)doxazosin varied from 10.4 pg·mL-1 to 13 ng·mL-1(r=0.9922), and the lowest limit of quantification was 10.4 pg·mL-1. An assessment of the matrix effect using post-extraction spiking method and post-column infusion method demonstrated that co-eluting matrix components did not significantly influenced the ionization of (-)doxazosin and prazosin (IS). Using the new method, we accurately measured (-)doxazosin concentration at 48 h after intravenous administration in the rats, and the concentration was 0.0344±0.0102 ng·mL-1. The method is specific, sensitive, and suitable for determining (-)doxazosin at very low concentration in rat plasma samples.

An overview of effects of traditional medicine on pharmacokinetics of western medicine / 药学学报

Traditional medicine (herb medicine) began to prevail again over last two decades, and it is about 70% of the world population taking herb medicine as supplement or alternative medicine according to a recent survey. The consumption of herb medicine increased exponentially in Canada, Australia and Europe during last 10 years. Since concomitant administration of herbal and western medicine has become a trend, it requires paying close attention to the problem. Herb-drug interactions have been extensively investigated worldwide, and there is an increasing concern about the clinical herb-drug interaction. In this review we introduced the current progress in the herb-drug interactions including evidence-based clinical studies and establishment of levels of evidence for herb-drug interaction; and in the related mechanisms including the induction and inhibition of metabolic enzymes, inhibition and induction of transport and efflux proteins, alteration of gastrointestinal functions, and alteration in renal elimination. We also analyzed both the achievements and the challenges faced in the concomitant administration of traditional Chinese medicine and western medicine.

Determination of doxazosin enantiomers in rat plasma and investigation of their chiral inversion / 药学学报

The study is to establish an HPLC method using fluorescence detector for the determination of doxazosin enantiomers and investigate their chiral inversion in vitro and in vivo. Ultron ES-OVM was taken as the chiral chromatographic column, and the column temperature was 30 degrees C. Isocratic elution using a mobile phase of phosphate buffer-acetonitrile (85 : 15, v/v) at a flow rate of 0.8 mL x min(-1) was done. The fluorescence detection was set at lambda(Ex) = 255 nm and lambda(Em) = 385 nm. Prazosin was used as the internal standard. (-) Doxazosin or (+) doxazosin added into rat plasma in vitro was determined after incubating in 37 degrees C water bath for 2, 5 and 10 days. (-) Doxazosin or (+) doxazosin was administered orally to the rats for one months. Plasma samples were taken at 8 h after the last administration. A good linear relationship was achieved when the concentration of doxazosin enantiomers was within the range of 4 - 2 000 ng x mL(-1). The average recovery for (-) doxazosin was 99.5% with RSD 3.6%, and for (+) doxazosin was 99.3% with RSD 4.3%. Chiral inversion was observed neither in vitro nor in vivo studies. The method is selective, accurate and reproducible, which is suitable for the detection of doxazosin enantiomers in rat plasma. The in vitro and in vivo studies indicate that chiral inversion occurs uneasily between (-) doxazosin and (+) doxazosin in the rat.