UPLC-QDA combined with pharmacology and chemometrics to analyze the correlation between the processing technology and color of Siegesbeckiae herba

In the Chinese Pharmacopoeia (2025 Edition), it is reported that Siegesbeckiae herba (SH) can be processed via a single herb preparation, demonstrating significant economic value and development potential. However, the quality evaluation of its processed products mostly relies on personal experience, which severely restricts the trade and circulation of SH. This study aimed to explore the correlation between different processing methods and the appearance color of SH, simplify the quality evaluation process, and improve the accuracy of sensory evaluation. Firstly, a colorimeter was used to quantify the appearance color of SH processed by different methods, UPLC-QDA was employed to establish the fingerprint of SH under different processing methods, and pharmacodynamic experiments were conducted to determine its analgesic and anti-inflammatory activities. Subsequently, chemometrics was applied to analyze the correlation between different processing methods and the appearance color of SH, thereby optimizing the optimal processing technology of SH. Finally, osteoarthritis experiments were performed to further verify the results. The colorimeter, fingerprint analysis, and pharmacodynamic results all confirmed that the SH steamed repeatedly for nine times exhibited a shiny black color and the best efficacy. This study provides a reference for the color evaluation of the processing standard of SH and the standardization of the macroscopic characteristics of traditional Chinese medicine.