ABSTRACT
Objective: To study the pharmacokinetics and tissue distribution of procesed Strychni Semen in rats after multiple administration at clinical dose. Methods: The rats were given procesed Strychni Semen by intragastric administration for single and several times. The plasma concentrations of brucine and strychnine in plasma and tissues of rats were determined by UPLC-Q-Orbitrap HRMS method, and the organizational distribution differences were compared to explore whether there was accumulation in the body. Results: After single intragastric administration of procesed Strychni Semen, the main pharmacokinetic parameters of brucine and strychnine were as follow: t1/2 was 10.59 and 8.39 h, tmax was 0.77 and 0.64 h, t1/2Ka was 5.38 and 2.63 h, Cmax was 2.97 and 10.83 ng/L, AUC0-t was 87.36 and 172.24 ng∙h/L, CL/F was 40 637.08 and 38 370.26 L/(h∙kg); Brucine and strychnine in processed Strychni Semen reached a steady state after 3 d of administration in rats. After the last administration, the main pharmacokinetic parameters of brucine and strychnine in rats were as follow: t1/2 was 7.07 and 4.75 h, tmax was 0.48 and 0.46 h, t1/2Ka was 3.23 and 1.09 h, Cmax is 5.77 and 34.83 ng/L, AUC0-t was 32.80 and 107.86 ng∙h/L, and CL/F was 75 920.52 and 43 871.54 L/(h∙kg). Compared with the single administration, the content of brucine and strychnine in the liver and kidney tissues was significantly reduced after multiple administrations, and there was no significant change in other tissues. Conclusion: The pharmacokinetics of brucine and strychnine in healthy rats is consistent with one-compartment model. Both of them have the pharmacokinetic characteristics of fast absorption in rats. After 3 d of administration, the serum concentrations of brucine and strychnine reached steady state, and the blood concentration was increased continuously with the increase of administration times. The content of each tissue did not increase after single and multiple administrations. It is suggested that long-term administration of brucine and strychnine will not cause the superposition of the concentration of brucine and strychnine in the blood of rats, which may lead to the occurrence of poisoning.