In vitro characterization and inhibition of the interaction between ciprofloxacin and berberine against multidrug-resistant Klebsiella pneumoniae.

Ciprofloxacin is a quinolone antibiotic used to treat Klebsiella pneumoniae infections in the clinic. Previous studies have demonstrated that berberine exhibits antibacterial activity and less acquired resistance related to efflux pumps. The multidrug efflux pump acrAB-tolC can be stimulated to expel as much toxic material as possible from the cells, but a detrimental effect can be produced owing to an overcrowded periplasm with excess expression products, which inhibits bacterial growth. In this study, the in vitro antibacterial activities of ciprofloxacin in combination with berberine were evaluated and compared with those of ciprofloxacin and berberine alone by evaluating the MIC, MBC and summation fractional IC against 20 clinical multidrug-resistant K. pneumoniae isolates, 1 quality control bacterium and 1 induced-resistance bacterium. Susceptibility tests showed that the MIC for the combination of berberine and ciprofloxacin was 1/2 that of the individual agents or less. Antimicrobial activities of 18.18% synergy and 77.27% additivity were found. Furthermore, synergism was verified through a time-kill assay, which suggested that the synergistic antibacterial effect of the two-drug combination may, to some extent, be related to the high expression of the acrAB-tolC and acrR multidrug efflux pumps. Indeed, the expression of these genes was increased >14-fold in the isolates affected by ciprofloxacin-berberine combination synergism.

[Relationship between the genetic polymorphism of CYP3A5 gene and the clinical response to bicyclol in chronic hepatitis B].

OBJECTIVE: To investigate the relationship between the genetic polymorphisms of CYP3A5 and the clinical effectiveness of Bicyclol on patients with chronic hepatitis B to make individual medication possible. METHODS: 34 cases of chronic hepatitis B were treated by bicyclol tablets for 24 weeks. Liver function indexes (ALT and AST) were determined before and after treatment. Blood CYP3A5 genotyping of each patient was determined by the PCR-RFLP analysis. RESULTS: All subjects were genotyped for the CYP3A5*3 gene and divided into different group. The groups comprised subjects with CYP3A5*3 carriers (n=18) and CYP3A5*1 carriers (n=16) which include CYP3A5*1/*1 (n=2) and CYP3A5*1/*3 (n=14). Compared with pre-treatment, the serum ALT and AST levels were decreased obviously in all patients. The mean percentage reduction of serum ALT and AST levels were significantly greater in subjects with CYP3A5*3 carriers (79.73% and 74.76%) than in those with CYP3A5*1 carriers (65.90% and 49.63%; P < 0.05) The recovery rates of ALT and AST were significantly highter in CYP3A5*3 carriers than those in CYP3A5*1 carriers (P < 0.05). CONCLUSION: CYP3A5 genotype has an impact on the therapeutic effects of Bicyclol. The subjects with CYP3A5*3 carriers is more effective than the subjects with CYP3A5*1 carriers. CYP3A5 genotyping may be helpful in predicting therapeutic effects of Bicyclol especially in the terms of decreasing ALT and AST.