An integrated strategy for quality control of Bletillae Rhizoma based on Q-marker

Bletillae Rhizoma, the rhizome of Bletilla striata (Tunb.) Rchb.f. (BS), a common traditional Chinese medicine, is used to achieve haemostasis and has been widely utilized in clinics for more than 2000 years. Owing to a shortage of resources, some unofficial substitutes such as Bletilla ochracea (BO), Bletilla formosana (BF), and Anthogonium gracile (AG) are also available on the market. This study aims to enhance the quality control of BS and distinguish unofficial substitutes. In this study, an integrated strategy based on Q-marker was performed. Multiple techniques, including untargeted plant metabolomics, serum pharmacochemistry, and activity testing, were combined to identify the Q-marker of BS. A simultaneous quantification method based on Q-marker was established using UPLC-DAD. Through untargeted plant metabolomics, 20 components were identified as differential constituents of BS for distinguishing counterfeits. Thirty-one components were identified or tentatively characterised in the BS extract, and 24 of the 31 components were detected in the serum of treated rats based on serum pharmacochemistry analysis. Six available, differential, and absorbed components, bletilloside A, batatasin III, gymnoside III, militarine, shancigusin I, and dactylorhin A, exhibited haemostatic or anti-inflammatory activities and were selected as Q-markers of BS. The contents of the six Q-markers in BS and the counterfeits were assayed, demonstrating clear differences across BS and the counterfeit species except BF. By integrating the above results, six identified components can be considered as Q-markers of BS. These markers, which are absorbed components associated with the traditional functions and biological activities of BS, can be used for the quality control of BS.