ABSTRACT
The apical sodium--dependent bile acid transporter (ASBT) is the main transporter to promote re-absorption of bile acids from the intestinal tract into the enterohepatic circulation. Inhibition of ASBT could increase the excretion of bile acids, thus increasing bile acid synthesis and consequently cholesterol consumption. Therefore, ASBT is an attractive target for developing new cholesterol-lowering drugs. In this report, a series of 1-(2,4-bifluorophenyl)-7-dialkylamino-1,8-naphthyridine-3-carboxamides were designed as inhibitors of ASBT. Most of them demonstrated potency against ASBT transport of bile acids. In particular, compoundwas found to have the best activity, resulting in 80.1% inhibition of ASBT at 10 μmol/L.
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.
ABSTRACT
Objective To determine the solubility and apparent oil/ water partition coefficient of sitafloxacin in different solvents. Methods High performance liquid chromatography (HPLC) was used. The column was Dikma Diamonsil C18 (2) (4. 6 mmí250 mm,5 μm). The mobile phase was 0. 05 mol·L-1 KH2 PO4 solution (pH was adjusted with H3 PO4 to 2. 4)-acetonitrile (7030). The column temperature was set at room temperature. The flow rate was 1. 0 mL·min-1 . The detection wavelength was 295 nm and the injection volume was 10 μL. The solubility of sitafloxacin and the apparent oil/ water partition coefficient at pH 2. 0,4. 3,5. 8,6. 6,7. 4,8. 0,10. 0 and 11. 2 were determined. Results The equilibrium solubility of sitafloxacin in water was 0. 44 mg·mL-1 and the apparent oil/ water partition coefficient was 0. 23 (lgP= -0. 64) at (37±2) ℃ . Sitafloxacin has the lowest equilibrium solubility (0. 13 mg·mL-1 ) and the highest apparent oil/ water partition coefficient in pH7. 4 buffer solution system. At pH>10 and pH<5. 8,the solubility of sitafloxacin increased obviously and apparent oil/ water partition coefficient decreased. Conclusion Sitafloxacin is insoluble in water and also poorly soluble in oil,but its solubility could be improved significantly in acidic or alkaline solution.