Comparative pharmacokinetic study of nine bioactive components in osteoarthritis rat plasma using ultra-performance liquid chromatography-tandem mass spectrometry after single and combined oral administration of Epimedii Folium and Chuanxiong Rhizoma extracts.

The herb pair Epimedii Folium-Chuanxiong Rhizoma (EF-CR), derived from the classical traditional Chinese medicine 'Xian Ling Pi San', has a distinctive compatibility therapeutic profile and is clinically safe and effective. This study aimed to investigate and compare the pharmacokinetic characteristics of nine analytes in osteoarthritis (OA) rat plasma after the oral administration of EF, CR or a combination of these two herbs. We developed an ultra-performance liquid chromatography method coupled with quadrupole linear ion-trap mass spectrometry to simultaneously quantify and assess the pharmacokinetics of icariin, epimedin A, epimedin B, epimedin C, icariside I, icariside II, ferulic acid, ligustilide and senkyunolide A of the EF-CR pair in the plasma of osteoarthritic rats. The pharmacokinetic parameters showed that the absorption of multiple components was significantly enhanced and residence time was prolonged in the EF-CR group (P < 0.05) compared to the single-herb group. These parameters revealed that the combination of EF and CR exhibited synergistic effects of the nine bioactive components, suggesting the potential application of the EF-CR combination for the treatment of OA.