Selection and evaluation of quality markers (Q-markers) of vladimiriae radix extract for cholestatic liver injury based on spectrum-effect relationship, pharmacokinetics, and molecular docking

Ethnopharmacological relevance: As a representative local medicinal herb produced in China, Vladimiriae Radix (VR) has been proven to exert hepatoprotective and choleretic effects, with particular therapeutic efficacy in cholestatic liver injury (CLI), as demonstrated by the VR extract (VRE). However, the quality markers (Q-markers) of VRE for the treatment of CLI remain unclear. Aim of the study: A new strategy based on the core element of "efficacy" was proposed, using a combination of spectrum-effect relationship, pharmacokinetics, and molecular docking methods to select and confirm Q-markers of VRE. Material and methods: First, the HPLC fingerprinting of 10 batches of VRE was studied, and the in vivo pharmacological index of anti-CLI in rats was determined. The spectrum-effect relationship was utilized as a screening method to identify the Q-markers of VRE. Secondly, Q-markers were used as VRE pharmacokinetic markers to measure their concentrations in normal and CLI rat plasma, and to analyze their disposition. Finally, molecular docking was utilized to predict the potential interaction between the identified Q-markers and crucial targets of CLI. Results: The fingerprints of 10 batches of VRE was established. The in vivo pharmacological evaluation of rats showed that VRE had a significant therapeutic effect on CLI. The spectrum-effect correlation analysis showed that costunolide (COS) and dehydrocostus lactone (DEH) were the Q-markers of VRE anti-CLI. The pharmacokinetic results showed that AUC((0-t)), C-max, CLZ/F, and V-Z/F of COS and DEH in CLI rats had significant differences (P < 0.01). They were effectively absorbed into the blood plasma of CLI rats, ensuring ideal bioavailability, and confirming their role as Q-markers. Molecular docking results showed that COS, DEH had good affinity with key targets (FXR, CAR, PXR, MAPK, TGR5, NRF2) for CLI treatment (Binding energy < -4.52 kcal mol(-1)), further verifying the correctness of Q-marker selection. Conclusions: In this study, through the combination of experimental and theoretical approaches from the aspects of pharmacodynamic expression, in vivo process rules, and interaction force prediction, the therapeutic effect of VRE and Q-markers (COS,DEH) were elucidated. Furthermore, a new idea based on the principle of "efficacy" was successfully proposed for screening and evaluating Q-markers.