Thrombin-based discovery strategy of bioactive-chemical quality marker combination for pollen of Typha orientalis by metabolomics coupled with chemometrics

Background: It is of utmost significance to choose the bioactive components as quality markers for ensuring the effectiveness of traditional Chinese medicine (TCM). Nonetheless, some markers are able to assess effectively the quality of TCM without considering the pharmacological mechanisms and intrinsic chemical complexities. Objective: This underscores the need to discover new and efficient markers which can assess both quality and mechanism of action. Herein, a strategy of bioactive-chemical quality marker combination was proposed to improve the level of the quality control of TCM by metabolomics coupled with chemometrics. Methods: A four-step plan was followed. Firstly, acquisition of metabolic features and component characterization of different batches of pollen of Typha orientalis C.Presl were performed using UHPLC-Q-TOF/MS. Secondly, the direct inhibitory effects of pollen of T. orientalis on thrombin was assessed by using chromogenic substrate method together with HPLC. Thereafter, bioactive-chemical marker combination associated with antithrombin segregation was screened using supervised classifiers. Finally, quantitative assay and prediction-model of selected markers were established for guarantying the quality of pollen of T. orientalis. Results: A total of 22 compounds were annotated based on comparison with previous work from pollen of T. orientalis by UHPLC-Q-TOF/MS. Citric acid and linolenic acid inhibited the thrombin activity with IC50 values, 0.52 +/- 0.02 and 0.51 +/- 0.02 mg/mL, respectively. A bioactive-chemical marker combination including citric acid, linolenic acid, typhaneoside, and isorhamnetin-3-O-neohesperidoside were discovered and selected as quality markers for evaluation of pollen of T. orientalis according to their capacity for inhibiting thrombin. Conclusion: The thrombin-based discovery strategy of bioactive-chemical marker combination was a powerful tool for screening the quality markers for evaluation of pollen of T. orientalis.