Insight of “Yin-Jing” medical property of Ligusticum chuanxiong Hort. via pharmacokinetics and tissue distributions by ultra-performance liquid chromatography-triple quadrupole mass spectrometry

Ligusticum chuanxiong Hort. (Chuanxiong, LC), as an important traditional Chinese medicine (TCM), can not only be used as a monarch herb but also be used as a classic "Yin-Jing" () medicine in compound prescriptions, e.g., Buyang Huanwu Decoction (BHD). Although LC has the effect of guiding components into the brain in BHD, there is still a lack of scientific evidence on this "Yin-Jing" effects. Herein, we used pharmacokinetics and tissue distributions to investigate "Yin-Jing" effects of LC. To simplify the study, four major constituents in BHD, i.e., Calycosin (CA), astragaloside IV (AI), paeoniflorin (PA), and amygdalin (AM) were combined to form a simple compound (abbreviated as CAPA here) to replace the original BHD in this paper. The Yin-Jing medical property of LC was confirmed by the compatibility of CAPA with LC or its different fractions (Fr. A ∼ Fr. F).To explore the "Yin-Jing" medical property of LC via pharmacokinetics and tissue distributions by ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QQQ-MS).The contents of CA, AI, PA, and AM were simultaneously determined by the established and validated UPLC-QQQ-MS method in different rat tissues and plasma after administration of CAPA with the combination of LC or Fr. A ∼ Fr. F. The pharmacokinetic parameters, e.g., Tmax, Cmax, AUC0-t and MRT0-t, were calculated to evaluate the efficiency of "Yin-Jing".The Cmax and AUC0-t of CA, AI, PA, and AM were remarkably increased in rat brain tissues compared with those of the control group after compatibility of LC. This demonstrated that LC has the Yin-Jing effects on brain tissues. Additionally, Fr. B or Fr. C might be the material basis by specifically studying the distributions of CA, AI, PA, and AM in brain tissue based on mutual compatibility. The effects of Fr. B and Fr. C on distributions of these constituents in other tissues or plasma was also studied to verify the effects of Yin-Jing of LC. The results showed that the same upward trend is found in heart, liver and plasma, but the intensity is insignificant as that in brain tissue. Furthermore, the Cmax and AUC0-t of some analytes in the rat spleen, lung, and kidney were significantly decreased compared with the control group (P < 0.05 or 0.01).LC has the function of Yin-Jing, especially guiding the components into the brain tissue. Moreover, Fr. B and Fr. C is suggested to be the pharmacodynamic material basis for the effect of Yin-Jing of LC. These finding explained that it was recommended to add LC into some prescriptions for treating cardiovascular and cerebrovascular diseases caused by Qi deficiency and blood stasis. This has laid a certain foundation for the research on the Yin-Jing efficacy of LC to better clarify the theory of TCM and guide the clinical application of Yin-Jing drugs.