简介：Objective:Toanalyzequantitativelythesynergisticandantagonisticeffectsofcombinedoxymatrine(OMT)and5-fluorouracil(5-GU)onacelllineofhumanlivercancer(HepG2)withmedian-effectprincipleinvitro.Methods:Themedian-effectprincipleandMTTmethodwereusedinthequantitativeanalysisofeffectsofthetwodrugs.Results:Cytotoxicactivityoftheindividualdrugsenhancedasdrugconcentrationincreased.Asfa=0.41,aCIequalto1indicatedadditivity;fa<0.41,aCIlessthan1indicatedsynergy;andfa>0.41,aCIgreaterthan1indicatedantagonism.Thesequenceofadministrationdidnotinfluencethecytotoxicactivityofthecombinedantitumordrugs.Theratioofdrugconcentrationwasafactorthatcaninfluencethekillingeffect.Conclusion:Thecombineddrugsinteraction(CI<1)wassynergisticatlowerconcentrationandantagonisticathigherconcentration.Theratioofdrugconcentrationisafactorthatcaninfluencethekillingeffect.