ABSTRACT
Currently, the resistance of first-line anti-tuberculosis drugs has made the prevention and treatment of tuberculosis increasingly difficult, posing a serious threat to global public health. Several studies have shown that efflux pumps are one of the important causes for bacteria to develop multi-drug resistance and extremely-drug resistance, and efflux pump inhibitors can inhibit the efflux of antibacterial drugs, thereby reducing bacterial drug resistance. Numerous natural products and synthetic compounds have been reported to possess efflux pump inhibitory activity, but they have not been applied in clinical settings because of their toxicity, pharmacokinetic properties, etc. Therefore, we summarized the efflux pump inhibitory activity, antimicrobial activity, and structure-activity relationships of reported efflux pump inhibitors against Mycobacterium tuberculosis in recent years, providing references for the development of new efflux pump inhibitors with better activity and lower toxicity.
ABSTRACT
Bile acids play critical roles in the regulation of metabolism and absorption of lipids. The ileal apical sodium-dependent bile acid transporter (ASBT) located at the enterocyte brush border is responsible for the reuptake of bile acids and the maintenance of bile acid homeostasis. Recently, a number of investigations have been made concerning the regulation and control of ASBT and the relationship between ASBT and intestinal inflammation, tumorigenesis, diabetes mellitus and hyperlipemia, which suggests ASBT as a potential therapeutic target of these diseases. In this review, advances in the study of above-mentioned issues were summarized.
ABSTRACT
The study aims to develop a rapid, specific and sensitive method for quantitative analysis of trace impurities in levofloxacin formulation using LC-MS/MS. The quality of the different formulations from 19 plants was evaluated in the contents of the impurities. The results indicated that there were 5 impurities in the samples, and the content was different in the products with same formulation by different plants. The products of 3 plants were in good quality with impurities level under 0.01%. Levofloxacin N4'-methyl quaternary impurity was first reported as the formulation impurity. The impurities were tightly correlated to the reservation of drug, process control of formulation and storage during transportation. The results suggest that our method is sensitive and specific to detect the trace impurities in formulation, and can be used to monitor the quality of commercial drug product.
ABSTRACT
For screening the potential drugs as anti-liver fibrosis candidates, we established a high- throughput drug screening cell model based on COL1A1 promoter. The activity of COL1A1 promoter and luciferase reporter gene can be elevated by TGF-β1, and inhibited by candidate drugs. We constructed a recombined plasmid with COL1A1 promoter and luciferase reporter gene pGL4.17, the activity of COL1A1 promoter was reflected by fluorescence intensity. COL1A1 promoter activity was detected by Dual-Luciferase Reporter Assay System, it came that the relative luciferase activity of COL1A1 promoter was 15.98 times higher than that of control group induced by TGF-β1, showing the recombined plasmid could be used in cell model. The recombined plasmid was transfected into human hepatic stellate cells LX2, detected the effect of potential drugs, and obtained a stable expression system through stable transfection and monoclonal cell culture. A sample which could reduce COL1A1 promoter activity signally by our cell model, decreased collagen I mRNA and protein expression detected by real-time RT-PCR and Western blotting. It indicates this novel cell model can be used in high-throughput drug screening of potential anti-liver fibrosis drugs.