ABSTRACT
Objective To investigate and compare the action of curcuminoids on the causal pathogens of Candida albicans growth.Methods The effects of curcumin (CUR) and demethoxycurcumin (DMC) on C.albicans growth were first investigated and compared by microcalorimetry coupled with multiple analytical methods.The quantitative thermo-kinetic parameters obtained from these curves were analyzed to show difference of the actions.Results By analyzing the main parameters screened from principal component analysis together with 50％ inhibiting concentration values,it was demonstrated that both CUR and DMC showed good antifungal activities and CUR was stronger.It was further concluded from structure-activity relationship that the existence of methoxy group might enhance lipophilicity of the mother nucleus,which made it easier for the molecular to enter into the cell membrane of fungi to inhibit its growth.Conclusion This study provides a new method for screening new antifungal agents with high efficacy and low toxicity.Meanwhile,it contributes to the application of curcuminoids as food additive,colorant,and drug.Microcalorimetry is real-time,online,and dynamic,and it could be used to characterize the subtle difference among the effects of synthetic and natural products on the vital process of fungi.
ABSTRACT
Bioassay, which construct the characteristics consistents with Chinese medical science, is the core mode and methods for the quality control of Chinese materia medica. Taking the bioassay of Radix Isatidis as an example, the contribution, status and application of bioassay in the quality control of Chinese materia medica were introduced in this article, and two key issue (the selection of reference and measurement methods) in the process of establishing bioassay were also explained. This article expects to provide a reference for the development and improvement of the bioassay of Chinese materia medica in a practical manipulation level.