Inhibitory effects of Danhong Injection and its major constituents on human cytochrome P450 enzymes in vitro

Drug-drug interaction between danshensu and irbesartan and its potential mechanism

To uncover the effect of danshensu on irbesartan pharmacokinetics and its underlying mechanisms.To investigate the effect of danshensu on the pharmacokinetics of irbesartan, Sprague-Dawley rats (n = 6) were orally administered 30 mg/kg irbesartan alone (control group) or pre-treated with 160 mg/kg danshensu (experimental group). The effect of danshensu on the metabolic stability of irbesartan in RLMs was examined by LC-MS/MS method. The effect of danshensu on CYP2C9 activity was also determined.Danshensu markedly increased the AUC(0-t) (9573 ± 441 vs. 16157 ± 559 μg/L*h) and Cmax (821 ± 24 vs. 1231 ± 44 μg/L) of irbesartan. Danshensu prolonged the t1/2 (13.39 ± 0.98 vs. 16.04 ± 1.21 h) and decreased the clearance rate (2.27 ± 0.14 vs. 1.19 ± 0.10 L/h/kg) of irbesartan. Danshensu enhanced the metabolic stability of irbesartan in vitro with prolonged t1/2 (36.34 ± 11.68 vs. 48.62 ± 12.03 min) and reduced intrinsic clearance (38.14 ± 10.24 vs. 28.51 ± 9.06 μL/min/mg protein). Additionally, the IC50 value for CYP2C9 inhibition by danshensu was 35.74 μM.Danshensu enhanced systemic exposure of irbesartan by suppressing CYP2C9. The finding can also serve as a guidance for further investigation of danshensu-irbesartan interaction in clinical practice.

Pharmacokinetic Comparison of Nine Bioactive Compounds of Guanxinshutong Capsule in Normal and Acute Myocardial Infarction Rats

BACKGROUND AND OBJECTIVES

Guanxinshutong capsules (GXST) are usually used to treat acute myocardial infarction (AMI), and the clinical effect of GXST is significant. However, there have been only a few studies on the pharmacokinetics of GXST against AMI injury. The objective of this study was to investigate the pharmacokinetics of nine bioactive compounds of GXST in normal and AMI rats.

METHODS

In this work, a rat model of AMI was established by ligating the left anterior descending coronary artery. The pharmacokinetic parameters of nine bioactive compounds (gallic acid, danshensu, protocatechuic aldehyde, rosmarinic acid, salvianolic acid B and salvianolic acid A, dihydrotanshinone I, cryptotanshinone, and tanshinone IIA) in the plasma of AMI and normal rats were compared under the same dose of GXST by a LC-MS/MS method. Then, we selected P-glycoprotein (P-gp) and some representative cytochrome P450 enzymes (CYPs) for molecular docking to further analyze the interaction between these compounds.

RESULTS

The pharmacokinetic studies showed that the area under the concentration-time curve (AUC) and maximum concentration (C_max) of phenolic acids were relatively large, while the half-life (T_½) of tanshinones was longer. Among the nine components, salvianolic acid B in AMI rats had the maximum area under the concentration-time curve (AUC_0-∞ = 1961.8 ng·h/mL), which showed a significant difference compared with normal rats (P < 0.05). Tanshinone IIA in AMI rats had the longest half-life (T_½ = 10.1 h), and it was markedly longer than that in normal rats (P < 0.01). In addition, compared with the normal group, the AUC, C_max, T_½ , and time to reach C_max (T_max) of gallic acid increased significantly in AMI rats (P < 0.05 or P < 0.01). For the molecular docking results, it was found that gallic acid may interact with CYP1A2, CYP2D6, and CYP2C9, while danshensu may interact with CYP2C9. Tanshinones may interact with CYP1A2, CYP2D6, CYP2C9, and P-gp.

CONCLUSIONS

The results suggest that the pathological injury caused by AMI has a significant impact on the pharmacokinetic characteristics of some active compounds in GXST, which are conducive to providing a reference and promoting rational clinical drug use.

Effects of Danhong injection, a traditional Chinese medicine, on nine cytochrome P450 isoforms in vitro

Danhong injection (DHI) is made from Salvia miltiorrhiza Bunge. and Carthamus tinctorius L. extract and is widely used in the clinical treatment of cardiovascular and cerebrovascular diseases. This study aimed to evaluate the effect of DHI on cytochrome P450 (CYP450) enzymes in vitro to predict drug-drug interactions based on CYP450 as combination therapy. To assess the inhibitory effect of DHI on CYP450, we detected the IC₅₀ value of DHI on CYP450 in vitro by liquid chromatography/tandem mass spectrometry (LC-MS/MS). Simultaneously, the induction effect of DHI on CYP450s was also evaluated. The relative induction ratios of DHI on CYP1A2, CYP2B6 and CYP3A4 activity were calculated by LC-MS/MS. The expression level of CYP3A4 mRNA was determined by reverse transcription PCR (RT-PCR). The LC-MS/MS data showed DHI intensively inhibit CYP2A6 activity and the intensity of inhibition was followed by CYP2C8, CYP3A4, CYP2C19, CYP2B6, CYP2D6, CYP1A2, CYP2E1 and CYP2C9 in vitro. The results of RT-PCR showed that there is a certain induction of DHI on CYP3A4 mRNA in human primary hepatocytes in vitro. The study suggested that drug-drug interactions might occur in clinical co-administration of drugs owing to the CYP2A6 inhibition and CYP3A4 induction.