ABSTRACT
In this experiment, the PK/PD fitting model of Chuanxiong(Chuanxiong Rhizoma) in the treatment of rheumatoid arthritis was established in the form of acupoint combined with external application gel paste. Firstly, the rheumatoid arthritis model was induced by ovalbumin, and the articular fluid of rabbits was extracted by microdialysis. The pharmacokinetic process of Chuanxiong in rabbit articular fluid was analyzed by UPLC-MS/MS, and the pharmacokinetic model was established. The pharmacodynamic effects of Chuanxiong on inflammatory factors IL-1β, TNF-α, and IL-6 were analyzed by enzyme-linked immunosorbent assay(ELISA). The pharmacodynamic model was established, and the PK/PD model was obtained by fitting the data of pharmacokinetics and pharmacodynamics. The results of pharmacokinetics showed that the concentration of ligustrolide A in the articular cavity by drug administration on classical acupoint Zusanli(ST 36) was higher than that by Yanglingquan(GB 34), which reflected the advantage of typical acupoint, while ligustrazine concentration was higher after administration through Yanglingquan than through Zusanli, which was different from the traditional acupoint theory. The results of pharmacodynamics showed that the drug had lag effect. The PK/PD model was constructed by fitting the data. When IL-1β was taken as the efficacy index, the PK/PD models of Chuanxiong in typical acupoint Zusanli group, atypical acupoint Yanglingquan group, and non-acupoint group were E=115.28C_e/(3 316.72+C_e), E=108.73C_e/(2 993.47+C_e), and E=101.34C_e/(3 028.51+C_e). When TNF-α was taken as the efficacy index, the PK/PD models of Chuanxiong in typical acupoint Zusanli group, atypical acupoint Yanglingquan group, and non-acupoint group were E=68.31C_e/(3 285.16+C_e), E=59.27C_e/(2 919.86+C_e), and E=53.61C_e/(2 862.87+C_e). When IL-6 was taken as the efficacy index, the PK/PD models of Chuanxiong in typical acupoint Zusanli group, atypical acupoint Yanglingquan group, and non-acupoint group were E=59.92C_e/(3 461.17+C_e), E=58.34C_e/(2 723.51+C_e), and E=49.17C_e/(2 862.76+C_e). The parameters showed that there were significant differences in E_(max), EC_(e50) and k_(eo). The analysis of data found that the PK/PD fitting effect of Zusanli, a typical acupoint, was the best, which proved that it was still the best site for drug administration. To sum up, it shows that there may be bidirectional selectivity between drugs and acupoints.