Effects of six kinds of Chinese herb extracts, including Folium Crataegi extract, Herba Epimedii extract, Folium Acanthopanacis Senticosi extract, Trifolium pratense L. extract, Folium Ginkgo extract and Radix Puerariae extract, on the activities of CYP450 isozymes (CYP1A2, CYP2C, CYP2E1, CYP2D, CYP3A) in rat hepatic microsomals were studied by using a UPLC-MS/MS (MRM) and cocktail probe substrates method. The results showed that effects of six kinds of Chinese herb extracts on each CYP450 isozyme activity were inhibitory. The IC50 of Folium Crataegi extract for the inhibition of rat microsomal CYP2D activity was only for 4.04 microg x mL(-1), which showed the highest inhibition; Trifolium pratense L. extract had strong inhibitory action to CYP2D, the IC50 value was 5.73 microg x mL(-1); Folium Crataegi extract also had strong inhibitory action on CYP2E1, the IC50 value was 10.91 microg x mL(-1). Furthermore, the IC50 of Folium Ginkgo extract for the inhibition of rat microsomal CYP3A, 2D, 2E1 activities were 45.12, 35.45 and 22.41 microg x mL(-1), respectively, and the IC50 of Folium Acanthopanacis Senticosi extract on the inhibition of rat microsomal CYP2E1 activity was 32.89 microg x mL(-1). In addition, mechanism of inhibition experimental results showed that the inhibiting abilities of Folium Crataegi extract and Radix Puerariae extract on each CYP450 isozyme increased with the increasing of the preincubation time, therefore, the inhibitory effects were a mechanism-based inhibition.

Theultraperformanceliquidchromatographycoupledwithmassspectrometry(UPLC-MS)was used to investigate the metabolic difference of the decoction of Radix Aconiti Preparata ( RAP ) and its co-decoctions with Radix Paeoniae Alba ( RAP-RPA ) or Radix Stephaniae Tetrandrae ( RAP-RST ) in rat intestinal bacteria. The principal component analysis ( PCA) of the relative contents of Aconitum alkaloids after metabolism was performed by SIMCA-P software. The score plots of PCA could successfully distinguish the three groups of RAP, RAP-RPA and RAP-RST. The result indicated that the differences of biotransformation among the groups of PAP, RAP-RPA and RAP-RST were significant. With the loading plot and independent-samples T test, seven relevant markers with the significant differences were found in the group of RAP-RPA, six relevant markers were obtained in the group of RAP-RST. The relative content of four markers in RAP-RPA was higher than that in RAP, and one marker in RAP-RST was higher than that in RAP. The relative contents of other markers were all lower than that in RAP. These markers may be the effective substance for explaining the different effects of Radix Aconiti Preparata before and after combination with Radix Paeoniae Alba and Radix Stephaniae Tetrandrae.

Enrichment of trace bioactive constituents and metabolites from complex biological samples is chal-lenging. This study presented a one-pot synthesis of magnetic polydopamine nanoparticles (Fe3O4@-SiO2@PDA NPs) with multiple recognition sites for the magnetic dispersive solid-phase extraction (MDSPE) of ginsenosides from rat plasma treated with white ginseng. The extracted ginsenosides were characterized by combining an ultra-high-performance liquid chromatography coupled to a high-resolution mass spectrometry with supplemental UNIFI libraries. Response surface methodology was statistically used to optimize the extraction procedure of the ginsenosides. The reusability of Fe3O4@-SiO2@PDA NPs was also examined and the results showed that the recovery rate exceeded 80％ after recycling 6 times. Furthermore, the proposed method showed greater enrichment efficiency and could rapidly determine and characterize 23 ginsenoside prototypes and metabolites from plasma. In com-parison, conventional methanol method can only detect 8 ginsenosides from the same plasma samples. The proposed approach can provide methodological reference for the trace determination and charac-terization of different bioactive ingredients and metabolites of traditional Chinese medicines and food.