Bioactivity-guided identification of quality control markers in Chuanxiong Rhizome at its optimal harvest period

Ligusticum chuanxiong Hort. is a widely used medicinal and edible plant in China. Its rhizome, Chuanxiong Rhizome (CR), is commonly employed in traditional Chinese medicine to promote blood circulation and alleviate blood stasis, especially in thrombotic diseases. However, the lack of scientific evidence supporting the determination of its optimal harvest time has hindered the development of standardized harvesting guidelines. In this study, the optimal harvest window of CR and its quality control markers (QCMs) were investigated. The antiplatelet aggregation biopotency (AAB) of CR collected at different harvest times was evaluated using a parallel-line assay. Metabolite profiling was conducted via UPLC-Q-TOF-MS/MS, and partial least squares regression was used to identify QCMs based on correlations between AAB and phytochemical composition. Molecular docking was applied to predict interactions between QCMs and antiplatelet-related targets, and a UPLC method was established for quantitative analysis. The optimal harvest period was determined to be from May 17th to May 22nd. Five QCMs were identified: ferulic acid, senkyunolide I, senkyunolide H, senkyunolide A, and Z -ligustilide. Ferulic acid exhibited a negative correlation with AAB, while the other four compounds showed positive correlations. Molecular docking revealed distinct target-binding profiles among QCMs. Harvest time had the greatest impact on the content of ferulic acid, senkyunolide H, and senkyunolide A, followed by senkyunolide I and Z -ligustilide. Except for Z-ligustilide, the other four compounds showed regular temporal variation, and the curve-fitting results followed the order: senkyunolide H > senkyunolide I > senkyunolide A > ferulic acid. Furthermore, Z -ligustilide, senkyunolide A, and ferulic acid were primarily affected by other QCMs in the rhizome, whereas senkyunolide I and senkyunolide H were influenced by compounds in both the rhizome and aerial parts. These findings provide a scientific basis for the quality evaluation and standardized harvesting of CR.