Dai D.-Z.,China Pharmaceutical University
Biochemical Pharmacology | Year: 2015
Over the period 1995-2012, David Triggle was a frequent visitor to the China Pharmaceutical University in Nanjing, China making many important contributions that enhanced the activities of the Research Division of Pharmacology at the University. In addition to providing collegial advice and facilitating interactions with the international pharmacological community, Professor Triggle's international reputation as a thought leader in the field of ion channel research and drug discovery provided important insights into the potential pathophysiological and therapeutic effects of targeting ion channels. This included the L-type calcium channel and the outward delayed rectified potassium currents of rapid (IKr) and slow (IKs) components in the myocardium. The Nanjing research team had been particularly interested in ion channel dysfunction in the context of cardiac arrhythmias, remodeling and drug discovery. With Professor Triggle's assistance, the relationship between an increase in ICa.L and other biological events including an enhancement of IKr and IKr currents, NADPH oxidase and endothelin receptor activation, down regulation of calcium modulating protein FKBP12.6, sarco/endoplasmic reticulum Ca2+ATPse (SERCA2A) and calsequens 2 (CASQ2), calcium leak at the diastole and endoplasmic reticulum stress, were evaluated and are discussed. Additionally, the organization of several international symposia was greatly enhanced by input from Professor Triggle as were the published research manuscripts in international pharmacology journals. During his association with the China Pharmaceutical University, Professor Triggle aided in enhancing the scientific standing of the Pharmacology department and was a highly effective ambassador for international research cooperation. © 2015 Published by Elsevier Inc.
Chen M.,China Pharmaceutical University
International journal of nanomedicine | Year: 2011
The purpose of the present study was to elucidate the antimicrobial activity and mechanism of silver nanoparticles incorporated into thermosensitive gel (S-T-Gel) on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. This study investigated the growth, permeability, and morphology of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa cells in order to observe the action of S-T-Gel on the membrane structure of these three bacteria. The cell morphology of normal and treated bacteria cells was assessed by transmission electron microscopy (TEM), and the effects of S-T-Gel on genome DNA of bacterial cells were evaluated by agarose gel electrophoresis. S-T-Gel showed promising activity against Staphylococcus aureus and moderate activity against Escherichia coli and Pseudomonas aeruginosa. The observation with TEM suggested that S-T-Gel may destroy the structure of bacterial cell membranes in order to enter the bacterial cell. S-T-Gel then condensed DNA and combined and coagulated with the cytoplasm of the damaged bacteria, resulting in the leakage of the cytoplasmic component and the eventual death of these three bacteria. In addition, the analysis of agarose gel electrophoresis demonstrated that S-T-Gel could increase the decomposability of genome DNA. These results about promising antimicrobial activity and mechanism of S-T-Gel may be useful for further research and development in in-vivo studies.
Qi J.,China Pharmaceutical University
International journal of nanomedicine | Year: 2011
A microemulsion is an effective formulation for improving the oral bioavailability of poorly soluble drugs. In this paper, a water-in-oil (w/o) microemulsion was investigated as a system for enhancing the oral bioavailability of Biopharmaceutic Classification System (BCS) III drugs. The microemulsion formulation was optimized using a pseudoternary phase diagram, comprising propylene glycol dicaprylocaprate (PG), Cremophor(®) RH40, and water (30/46/24 w/w). The microemulsion increased the oral bioavailability of hydroxysafflor yellow A which was highly water-soluble but very poorly permeable. The relative bioavailability of hydroxysafflor yellow A microemulsion was about 1937% compared with a control solution in bile duct-nonligated rats. However, the microemulsion showed lower enhanced absorption ability in bile duct-ligated rats, and the relative bioavailability was only 181%. In vitro experiments were further employed to study the mechanism of the enhanced effect of the microemulsion. In vitro lipolysis showed that the microemulsion was digested very quickly by pancreatic lipase. About 60% of the microemulsion was digested within 1 hour. Furthermore, the particle size of the microemulsion after digestion was very small (53.3 nm) and the digested microemulsion had high physical stability. An everted gut sac model demonstrated that cumulative transport of the digested microemulsion was significantly higher than that of the diluted microemulsion. These results suggested that digestion of the microemulsion by pancreatic lipase plays an important role in enhancing oral bioavailability of water-soluble drugs.
Zhang B.,China Pharmaceutical University |
Studer A.,University of Munster
Chemical Society Reviews | Year: 2015
Nitrogen heterocycles belong to a highly important class of compounds which are found in various natural products, biologically active structures, and medicinally relevant compounds. Therefore, there is continuing interest in the development of novel synthetic methods for the construction of nitrogen containing heterocycles. Recently, radical insertion reactions into isonitriles have emerged as an efficient and powerful strategy for the construction of nitrogen heterocycles, such as phenanthridines, indoles, quinolines, quinoxalines, and isoquinolines. This review highlights recent advances in this fast growing research area and also includes important pioneering studies in this area. © The Royal Society of Chemistry 2015.
Cheng X.L.,China Pharmaceutical University
The Analyst | Year: 2013
In this work, a rapid and simple method based on matrix solid-phase dispersion (MSPD) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed. Guge Fengtong preparation (GGFT), a traditional Chinese herbal medicine, was investigated for validation, and eight major constituents were determined including four saponins (protodioscin, protogracillin, pseudoprotodioscin and dioscin) and four gingerols (6-gingerol, 8-gingerol, 10-gingerol and 6-shogaol). Response surface methodology and desirability function were employed to optimize the extraction conditions, such as dispersant, dispersant/sample ratio, solvent concentration, and elution volume, of MSPD. Results showed that MSPD using C18 (1.75 g) as the dispersant material and methanol (89%, v/v) as the eluting solvent (12.00 mL) resulted in a high extraction efficiency. MSPD extraction had the advantages of combining extraction and clean-up in a single step, was less time consuming and required lower solvent volumes compared with conventional methods. Quantification of chemical compounds from GGFT preparations were performed using UPLC-MS/MS in multiple-reaction monitoring mode. The proposed method afforded a low limit of detection ranging from 0.02 to 0.40 ng for saponins and gingerols. For all the analytes, recoveries ranged from 80.9% to 103% and repeatabilities were acceptable with relative standard deviations of less than 6.81%. The proposed MSPD-UPLC-MS/MS method was successfully utilized to analyze five batches of GGFTs, and the results demonstrated that this method is simple, efficient and has potential to be applied for the quality control of herbal preparations.