Identifying quality markers of Mailuoshutong pill against thromboangiitis obliterans based on chinmedomics strategy

Mailuoshutong pill (MLSTP) is a traditional Chinese medicine (TCM) for the treatment of Thromboangiitis obliterans (TAO, Buerger's disease) which is a segmental non-atherosclerotic inflammatory occlusive disorder. However, the mechanism and quality standards of MLSTP have not been sufficiently studied.This work aims to investigate the potential mechanisms and quality markers (Q-markers) of MLSTP treating TAO based on the chinmedomics strategy.The therapeutical effect of MLSTP on TAO rats was evaluated by changes in body weight and clinical score, regional blood flow velocity and perfused blood vessel distribution, hematoxylin-eosin (H&E) staining, serum metabolic profile. Moreover, both endogenous metabolites and exogenous components were simultaneously detected in serum based on ultra-high performance liquid chromatography coupled with a Q Exactive hybrid quadrupole-orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS), and multivariate analysis was applied to identify the biomarkers, as well as the dynamic changes of metabolites were observed to explore the mechanism of action of MLSTP. In addition, the pharmacodynamic material basis were identified by correlation analysis between biomarkers and absorbed constituents. Finally, the Q-markers of MLSTP were determined according to the screening principles of Q-marker and validated the measurability.MLSTP treatment alleviated disease severity of TAO, reduced inflammatory infiltration, and ameliorated vascular function. 26 potential biomarkers associated with glutamate metabolism, linoleic acid metabolism, arachidonic acid metabolism and so on were identified. Besides, 27 prototypical components were identified in serum, 16 of which were highly correlated with efficacy and could serve as the pharmacodynamic material basis of MLSTP against TAO. In addition, 7 compounds, namely, sweroside, chlorogenic acid, calycosin-7-glucoside, formononetin, paeoniflorin, liquiritigenin and 3-butylidenephthalide, were considered as potential Q-markers of MLSTP. Ultimately, the measurability of the seven Q-markers was validated by rapid identifcation and quantifcation.This study successfully clarified the therapeutic effect and Q-markers of MLSTP by chinmedomics strategy, which is of great significance for the establishment of quality standards. Furthermore, it provides a certain reference for the screening of Q-markers in TCM prescriptions.