ABSTRACT
This paper was aimed to study the human plasma protein binding rate of diterpene ginkgolides meglumine injection.The equilibrium dialysis was used to determine the human plasma protein binding rate of ginkgolide A (GA),ginkgolide B (GB) and ginkgolide K (GK) in diterpene ginkgolides meglumine injection.The LC-MS/MS method was used for the content determination of ginkgolides.And then,the plasma protein binding rate was calculated.The results showed that there was no interference from other ingredients for the determination of ginkgolides.The calibration curve of the analytes was in good linearity in certain range of contents.The precision and stability of the analytes met the methodology requirements.After 8 h incubation,the human plasma protein binding rate of GA,GB and GK achieved balance.The human plasma protein binding rate of GA (0.34,1.70 and 8.51μg·mL-1) was 84.03%-88.11%; the human plasma protein binding rate of GB (0.62,3.09 and 15.5μg·mL-1) was 41.21%-53.56%; the human plasma protein binding rate of GK (0.04,0.20 and 1.01μg·mL-1) was 45.24%-59.59%.It was concluded that the method was simple,rapid and sensitive,which met the analysis requirement for biological samples.GA had a high plasma protein binding rate; GB and GK had medium plasma protein binding rate.
ABSTRACT
This study was aimed to investigate the induction effect ofRe-Du-Ning (RDN) Injection on rat liver microsome CYP450 enzymes. SD rats were randomly divided into the solvent control group, positive control group as well as the low, middle and high dose group of RDN (1, 2, 4 mL·kg-1·d-1). After drugs were administrated continuously for 7 days, the rats were sacrificed. The liver was weighed and prepared to microsomes. Meanwhile, the liver coefficients of rats were calculated. And the protein content was detected by BCA method. Finally, activities of five important subtypes of CYP450 enzymes such as CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A1/2 were measured by the“cocktail” method. The results showed that the levels of liver coefficients, microsome yield rate and activities of CYP450 subtypes increased significantly in the positive control group compared with the solvent control group (P < 0.01). There was no significant difference on the levels of liver coefficients, microsome yield and protein content between the low and middle dose group of RDN. However, there was significant difference on the levels of liver coefficients and microsome yield in the high dose group (P < 0.05). In terms of the influence on enzyme activity, RDN Injection can significantly induce the activities of CYP1A2 with dose dependence. It can induce the activities of CYP2C9 and CYP2C19 at the middle and high dose. However, there was no obvious influence on the activities of CYP3A1/2 and CYP2D6. It was concluded that the positive control group can obviously induce activities of CYP450, which can be used in the evaluation of induction experiments. RDN Injection had induction effect on CYP1A2, CYP2C9 and CYP2C19. But it had no influence on the activities of CYP3A1/2 and CYP2D6.