五环三萜类柴胡皂苷单体抗耐MRSA活性研究

目的对柴胡进行有效成分分离,并对其抗菌作用明确的成分进行结构测定,确定其分子结构,得到结构明确的五环三萜类活性单体Bp3(saikosaponines,Bp3)。进一步深入研究该单体的耐甲氧西林金黄色葡萄球菌(methicillin-resistant staphylococcus aureus,MRSA)作用及其与头孢唑林的协同作用。方法参照美国临床实验室标准化委员会(national committee for clinical laboratory standard,NCCLS)标准,测定Bp3对20株MRSA的MIC及其与头孢唑林的协同作用。结果Bp3对MRSA的抑菌作用优于头孢唑林且联合用药时显著减少了每一药物的最低抑菌浓度值(minimal inhibitory concentration,MIC),在20株耐甲氧西林金黄色葡萄球菌均表现为协同或相加作用方式。结论结构明确的五环三萜类单体Bp3对MRSA有一定的抑制作用,且与头孢唑林有协同或相加作用。

Activity of monomers of pentaeyclic triterpennoids of Saikosaponines against Methicillin-resistant Staphylococcus aureus

Objective The chemical structure of the antimicrobial activity of isolated monomers from Bupleurum kunmingense is pentaeyclic triterpennoids(Bp3).The effect of Bp3 on Methicillin-resistant Staphylococcus aureus(MRSA)and synergism of Bp3 with Cephazolin were studied.Methods The minimal inhibitory concentrations(MIC) of Bp3 and synergism effects of Bp3 with Cephazolin on 20 MRSA strains were detected by microdilution method and checkerboard microdilution method according to the Standard of National Committee for Clinical Laboratory(NCCLS).Results The inhibitory effects of Bp3 on MRSA were better than Cephazolin.When Bp3 and Cephazolin were given in combination,the MIC of this combination to MRSA was significantly reduced.Bp3 and Cephazolin showed synergism effects or additioned effects on 20 MRSA strains.Conclusion Bp3 can inhibit MRSA to some extent.The combination effect of Bp3 and Cephazolin is significantly more active than any drug alone against MRSA.