In recent years, owing to the abuse of antibiotics, the widespread of resistant bacterial strains became a serious threat to public health. This status demands development of new antibacterial agents with novel mechanisms of action. The reason for the limited new antibacterials is the small number of effective therapeutic targets, which cannot meet the current needs for the multiple drug-resistant treatment. Screening for new targets is the key step in the development of novel antibacterial agents. Peptidoglycan is the main component of the cell wall of bacteria, which is essential for survival of pathogenic bacteria. Within the biochemical pathway for peptidoglycan biosynthes is the Murligases, described in this review as highly potential targets for the development of new classes of antibacterial agents. This review provides an in-depth insight into the recent developments in the field of inhibitors of the Mur enzymes (MurA-F). Moreover, the reasons for the lack of candidate inhibitors and the challenges to overcome the hurdles are also discussed.

Population pharmacokinetics is an emerging discipline developed from the combination of classical pharmacokinetic compartment model and statistics principles, which has been received more and more attention in recent years. Population pharmacokinetics plays important roles in all stages of new drug research. In the early preclinical phase, population pharmacokinetic analysis can help to achieve the preliminary prediction of parameters from animal to human, optimize clinical trial designs, and shorten the time required for new drugs from laboratory to clinical trials. In clinical trials and applications stage, population pharmacokinetic research can help researchers investigate the related covariates that affecting pharmacokinetic behavior of patients comprehensively, and find potential drug-drug interactions in clinical. In addition, population pharmacokinetics has a unique advantage in pediatric drug development due to its strong analysis ability of sparse data. This paper provides a summary on the history and methods of population pharmacokinetics, and the application in new drug discovery and development.

Translating of scientific advances into clinical practice is a major challenge in the stroke research field in the past decades. There were many reasons involved:animal models might not accurately capture all aspects of clinical stroke in humans, the blind and randomized design principle was not closely followed, the inclusion and exclusion criteria was not previously established, sample size was inadequate, endpoint was not scientific nor blindly assessed, inadequate reporting of data and statistical flaws. To bridge the gap between experimental and clinical research, international consortia have attempted to establish standardized guidelines for study design and data report, which include optimizing animal models as well as experimental design, using innovative approaches to assess endpoint, making raw data and negative results available, establishing prior registration mechanism, conducting multicenter preclinical randomized controlled trials (pRCTs), systematic reviews and meta-analysis of preclinical studies, evolving the original focus on neuroprotection into a broader consideration of the role of neurovascular unit and ischemic cascade.

D-galactose (D-gal)-induced aging model is widely used in the study of the pharmacodynamics of antiaging drugs. The model has a shorter life-span, disorders in learning and memory, reduced immune function and other aging characteristics. Regular and quantitative injection of D-gal solution to rats can produce symptoms of natural aging models that are used in screening of antiaging drugs, and their pharmacological activities. This paper provides a summary of the mechanism of rat model induced with D-gal solution. The methods of building and evaluation of the aging models are provided. The theoretical basis is included to facilitate the subsequent research and experiment in the mechanism study of aging and antiaging medicines.

Our research was designed for on-line detection of multi-index in the concentration process of Ganmaoling granules by integration of near infrared spectroscopy and automatic control system. First, on-line detection system was set up in the concentration tank for Ganmaoling granules production. Spectra were scanned and values of chlorogenic acid, linarin, solid content and relative density were measured. Models of partial least squares regression were built and imported into near infrared workstation. By connecting the control system, real-time multi-index values were determined automatically in the concentration process. Results showed that correlation coefficients of chlorogenic acid, linarin, solid content and relative density models were 0.963, 0.989, 0.993 and 0.918, respectively. Relative standard errors of prediction were 3.71%, 4.28%, 4.17% and 0.24%, respectively, indicating a good performance and high accuracy of the models. Real-time data collection during the whole process was measured by the near infrared detecting system in the control system. In conclusion, the near infrared detection system is able to perform real-time automatic determination of multi-index in the concentration process of Ganmaoling granules with significant advantages.

To study the metabolic products of main compounds of Chuankezhi injection in rat, 12 Sprague Dawley rats were classed into 2 groups, a blank control group and an intermuscular administration group, respectively. Rat feces and urine samples were collected from 0-24 h and 24-48 h after administration. All the samples were ultrasonically treated with methanol and then analyzed using LC-LTQ Orbitrap MSn. By comparison with the total ion chromatogram of samples from the blank control group, the metabolites in the samples of drug-treated group were screened. These metabolites were further analyzed by multistage product ion scanning and comparison of retention time with reference substances. As a result, a total of 12 flavonoid metabolites were tentatively identified from the rat feces and no metabolite was discovered in the rat urine. Epimedin C and icariin were detected in the rat blood samples after 30 min of administration, but their metabolites and other original flavones were not detected. Furthermore, no original flavones and their metabolites were detected in rat blood samples after 2 and 4 h of administration. The potential metabolism paths were further characterized and the principal in vivo transformation of flavones from Chuankezhi injection were deglycosylation, dehydration, methylation, oxidation and isomerization in rats.

The biological potency assay and chemical fingerprint chromatogram were applied to quality evaluation of rhubarb. Using the biological potency as indicators, we evaluated the differences in quality of multiple batches of rhubarbs and related products. Using the platelet aggregation analyzer, we determined platelet aggregation rate in the different rhubarbs preparations, and calculated the biological potency based on the simplified probit principle. UPLC was adopted to establish the fingerprint spectra for rhubarbs. The spectral efficiency correlation analysis between chromatograms and biological potencies were conducted using the double variables of SPSS 22.0 software. We used three chemical composition to verify the potency. The biological potency results suggest that Rheum palmatum has a more potent activity than Rheum tanguticum, and wine-treated rhubarb had a higher potentcy than charred. We identified 10 elements in the Fingerprint Spectrum. The relevant elements including rhein-8-O-β-D-glucoside, emodin-8-O-β-D-glucoside and rhein have the strongest activity in the inhibition of platelet aggregation. In conclusion, this study provides a analytical method for rhubarb biological potency based on determination of the maximum antagonism rate model. The rhein may be the effective substance. It may serve as a reference in the quality control of wine processed rhubarb products.

In this study, the endocytosis pathway of heparosan and its intracellular distribution were investigated in MCF-7 tumor cells and COS7 normal cells. The endocytosis inhibition and cellular probe location experiments showed that MCF-7 tumor cells took heparosan more efficiently and selectively than COS7 cells. The cellular uptake of heparosan was energy-dependent in both MCF-7 tumor cells and COS7 normal cells. Moreover, the major endocytosis pathway of heparosan into MCF-7 tumor cells was caveolin-mediated endocytosis and macropinocytosis. The internalized heparosan was mainly located in lysosomes of the cells.

In this study, water-dispersible magnetic iron oxide (Fe₃O₄) nanoparticles were synthesized with solvothermal method. The nanoparticles were characterized with a transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The in vitro magnetic resonance response and photothermal conversion characteristics of the nanoparticles were evaluated. In addition, the cellular uptake, cytotoxicity and biodistribution were studied. Finally, magnetic resonance/photothermal dual-modal imaging effect of the as-synthesized Fe₃O₄ nanoparticles was investigated in the tumor-bearing mice. The results showed that the obtained magnetic nanoparticles were uniform with a mean diameter of about 125 nm. Moreover, the superparamagnetic Fe₃O₄ nanoparticles showed remarkable magnetic resonance response and photothermal conversion properties. The results of cellular experiments showed that the cell viability was nearly 85% even the concentration of the nanoparticles was up to 1 000 μg·mL^-1, an indicator of good biocompatibility. In addition, the nanoparticles could be taken up by the tumor cells and then located in the cytoplasm. After intravenous injection, the nanoparticles were tended to enrich in the tumor over time, which is helpful in achieving dual-modal magnetic resonance/photothermal imaging. In sum, the obtained Fe₃O₄ nanoparticles showed great potential to be applied for multi-modal bio-imaging which may play an important role in the diagnosis of tumors.

Inhibition of apoptosis induced by oxidative stress is an effective way to reduce myocardial injury. In this study, we used H₂O₂-stimulated rat cardiac myoblast cell line (H9c2) as an oxidative damage model. Curcumin (Cur) was chosen as a model drug and mesoporous silica nanoparticles (MSNs) were chosen as the carrier to construct a Cur-loaded delivery system (Cur@MSNs) and to examine its protective effects against oxidative damage. The MSNs guaranteed efficient loading and controlled release of Cur. Besides, the hydrophilicsilanol groups on the surface of MSNs promoted the Cur solubility in water and increased its cellular uptake amount, which improved the bioavailability of Cur. The results suggest that the Cur@MSNs was pharmacologically active in the reduction of the oxidative damage of H9c2 cells. It was verified that a great decrease of reactive oxygen species was inducted by Cur@MSNs, which led to the protective effects against oxidative damage.