Abstract
Wuzhi capsule (WZC) is a preparation of an ethanol herbal extract of Schisandra sphenanthera(Nan-Wuweizi), with its main active ingredients including schisandrin, schisandrol B, schisantherin A, schisanhenol and deoxyshisandrin. WZC and tacrolimus are often co-administered for the treatment of drug-induced hepatitis in organ transplant recipients in China. Recently, it was reported that WZC could significantly increase the blood concentration of tacrolimus. The purpose of this study was to investigate whether and how WZC affects the pharmacokinetics of tacrolimus in rats. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to determine the plasma concentration of tacrolimus. The results showed that WZC increased the mean plasma concentration of tacrolimus. Compared with administration of tacrolimus alone (Cmax, 18.87±10.29 ng/mL; AUC0&→t, 40.98±37.07), a single intragastric administered dose of WZC increased, the pharmacokinetic parameters of tacrolimus (Cmax, 59.42±30.32 ng/mL; AUC0→t, 239.71±28.86) by five folds in rat plasma. After pretreatment with WZC for 12 days, there were still significant increases in AUC0→t (from 40.98±37.07 to 89.21±26.39 h ng/mL; p < 0.05) and Cmax (from 18.87±10.29 to 43.16±10.61 ng/mL; p < 0.05) of tacrolimus compared with oral of tacrolimus alone, suggesting that WZC increased the exposure of tacrolimus by one or more mechanisms. The increase in tacolimus Cmax by WZC was dose dependent. The effect of WZC on Tacrolimus AUC0→t also increased with dose with a maximal effect observed at 450 mg/kg (825.34 ng h/mL). No further increases in tacolimus AUC0→t were observed at WZC dose above 450 mg/kg. It is suggested that due to the effect of WZC on the pharmacokinetics of tacrolimus, the herb-drug interaction between WZC and tacrolimus should be taken into considered in clinical practice.
- adverse drug reactions
- analytical pharmacology/toxicology
- cytochrome P450
- drug-drug interactions
- drug-induced hepatotoxicity
- HPLC
- immunosuppression
- P450 mechanism
- The American Society for Pharmacology and Experimental Therapeutics