Objective To observe the antigiardial activity of osthole. Methods We firstly analyzed the effect of different concentrations of osthol on growth inhibition of Giardia lambliatrophozoites,and then described that the effect of osthole on cell viability assays at IC50 concentration. Results The growth inhibition assay showed that all the different concentrations of osthole have certain of growth inhibition.As the concentration of osthole increased,the more obvious growth inhibition,especially the 78.62% reduc...