Antibacterial Mechanism Of Fraxetin On Staphylococcus Aureus

Fraxetin as a natural coumarin compounds of Cortex Fraxini, it has Anti-tumor, anti-bacterial, anti-inflammatory, and neuroprotective effect. And have a wide range of cLinical application.It Is a extremely important and has great development and utilization of the value of Chinese herbal medicines. However, its pharmacological effects, pharmacokinetics, cLinical applications need to be further in-depth study and exploration. This article with Staphylococcus aureus as strains tested. Carried out a systematic study on the the Fraxetin antibacterial activity and antibacterial mechanisms. The results are as follows:(1) Using the Oxford cup method and TTC method study experimental results show that the Fraxetin pigment by StaphyLococcus aureus has a strong inhibitory activity of the antibacterial activity of the Fraxetin. MIC is O.Olmg/mL.(2) By measuring the content of medium conductivity and macromolecules changes after the role of the Fraxetin bacterial cell membrane damage were studied. The results show that Fraxetin can be changed by the Staphylococcus aureus cell membrane permeability, but does not undermine the integrity of the cell membrane.(3) By DAPI staining to examine study on cell DNA, RNA content, The results show that DNA content decreased40.35%in the Fraxetin after20h and RNA content decreased43.75%. That Fraxetin inhibit the synthesis of nucleic acids by Staphylococcus aureus.(4) Using the protein bands in SDS-PAGE analysis of changes in soluble protein content were determined before and after the role of the Fraxetin. The results showed that total bacterial so proteins decreased55.47%after20h of drug action. Description Fraxetin inhibit bacterial soluble protein synthesis.(5) By the helicase of plasmid analysis to study the Fraxetin on the activity of DNA topoisomerase. The resuLts showed that drug has obvious inhibition of topoisomerase I and topoisomerase II.(6) UV-Vis spectrometry and agarose gel electrophoresis the Fraxetin and mode of action of DNA were studied. Fraxetin absorption peak will Red-shifted after of drug action, absorption peak of the hypochromic effect. And Fraxetin make the supercoiled DNA heLicase and produce part of the fracture. The resuLts showed that Fraxetin is to play a roLe by embedding DNA.(7) Detection Fraxetin and DNA binding sites using the restriction endonuclase map. The results show that after of drug action, Taq estriction enzyme eLectrophoresis changed significantly. Show that Drugs and DNA binding sites o may be in two enzymes restriction site T/CGA.