甘草总黄酮对艰难梭菌的体内外抗菌作用研究OA北大核心CSTPCD

The in vitro and in vivo antibacterial activities of total flavonoids from Glycyrrhiza uralensis(TFGU)against Clostridium difficile and the possible mode of action were investigated,which can provide basis for the prevention and treatment of CDI and the efficient utilization of licorice.Micro-broth dilution method and bacterial counting method were applied to determine the minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC).The growth curve and killing curve of TFGU on C.difficile were also evaluated.The membrane integrity was investigated by scanning electron microscope,propidium iodide(PI)uptake assay,determination of extracellular ATP and protein.Finally,CDI model was successfully established on mice and in vivo efficacy of TFGU was also evaluated.The results showed that MIC and MBC of TFGU against C.difficile were 12.5 and 25 μg/mL,respectively.TFGU showed a rapid bactericidal manner.Bacterial membrane was significantly disrupted by TFGU,which lead to the leak-age of ATP and protein,morphological change and finally death of bacteria.The body weight decrease of mice was significantly alleviated by TFGU and the 7-day survival rate was 100％,which was equal to van-comycin.In conclusion,TFGU showed significant in vitro and in vivo antibacterial activity against C.dif-ficile and disruption of bacterial membrane maybe the possible mechanism of action.