Chemical profiling and antioxidant evaluation of Yangxinshi Tablet by HPLC-ESI-Q-TOF-MS/MS combined with DPPH assay

Yangxinshi Tablet (YXST) is a Chinese patent medicine commonly used to treat cardiovascular diseases. However, its detailed chemical basis and mechanisms of action have not been clarified. In this study, high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC ESI-Q-TOF-MS) was applied for comprehensive analysis of the chemical constituents in YXST. A total of 127 compounds, including 19 phenolic acids, 12 alkaloids, 51 flavanoids, 32 triterpenoids, 2 lignans, 2 phenylethanoid glycosides, 2 anthraquinones, 1 coumarin, and 6 other compounds, were identified or tentatively deduced by comparing their retention times and MS spectra with those of authentic standards or literature data. To further prove the antioxidant activity of YXST, its free radical scavenging capacity was assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) spectrophotometric assay and the antioxidants in YXST were rapidly screened by DPPH-HPLC experiment. Especially, salvianolic acid A and salvianolic acid B showed excellent DPPH scavenging activities with the IC50 of 151.9 and 275.6 mu g/mL, respectively, which were stronger than that of L-ascorbic acid (positive control) with the IC50 of 297.1 mu g/mL. Additionally, these two most potent antioxidants were detectable in rat plasma after oral administration. In conclusion, this study reported important clues for the further pharmacological and clinical studies of YXST. Meanwhile, it provided a practical strategy for rapid screening and identifying of in vivo antioxidant in traditional Chinese medicine preparations.