Application of pharmacodynamics-based optimization to the extraction of bioactive compounds from Chansu

Natural medicines are now gaining increasing acceptance around the global scope. Due to the complexity of composition, it is imperative to adopt a unique evaluation system, which is not confined to the content of finite marker compounds. This research presents the successful application of pharmacodynamics-based optimization to the ultrasound-assisted extraction of Chansu, a widely used natural medicine with complex bioactive ingredients. The effect of solvent concentration, solvent to solid ratio, extraction time and particle size, on two response indexes (extraction yield of total content of bufalin, cinobufagin and resibufogenin and anticancer activity) were evaluated by response surface methodology (RSM). Two models were built based on two response indexes, and both of them provided accurate predictions. Compared with extraction yield-based optimization, pharmacodynamics-based optimization aligns well with the integrity and complexity of natural medicines. Moreover, the pharmacodynamics-based optimization gives a more economical and efficient optimal condition, which is specifically embodied in the coarser requirement for particle size and the saving of extraction time and solvent. The recommended extraction conditions were methanol concentration of 83.54% (v/v), solvent to solid ratio of 26.23 mL/g, extraction time of 40.43 min and particle size of 61 mesh (0.212–0.25 mm). The present study elaborated the feasibility and implication of pharmacodynamics-based optimization, which provides useful information for further research on the extraction process of natural medicines.