The variation in the major constituents of the dried rhizome of Ligusticum chuanxiong (Chuanxiong) after herbal processing

Background: Rhizoma Chuanxiong (RC; Chuanxiong), which is the dried rhizome of Ligusticum chuanxiong (Umbelliferae), is commonly used in Chinese medicine (CM) for improving blood circulation and dispersing blood stasis. RC is usually processed before use in clinical practice to enhance its therapeutic efficacy. This study aimed to investigate the temporal variations of the major constituents of RC by HPLC-DAD-MS during herbal processing to investigate the effects of an adjuvant (e.g., wine), steaming vs stir-frying and the optimal processing time. Methods: An HPLC-DAD-MS method was developed to determine the major constituents of the RC processed by one of the four processing methods, i.e., stir-frying, steaming, stir-frying with rice wine and steaming with rice wine. Processing was conducted over 60 min. Six major compounds, namely ferulic acid, senkyunolide I, senkyunolide H, senkyunolide A, Z-ligustilide and levistolide A, were selected as markers to analyze the effects on the markers' levels of the different processing methods and optimize the processing time. Results: The results indicated that (a) processing with wine had no discernible impact on the amounts of the six chemical markers in RC; (b) the amounts of the major constituents of RC subjected to steam processing were higher than those of the RC subjected to stir-fry processing. Conclusion: Among the four different methods evaluated for RC processing, steaming was better and the optimal time for steaming RC was 40 min.