Clinical metabolomic analysis of Danlou tablets with antioxidant effects for treating stable angina pectoris

The Danlou tablets (DLT) is a patented Chinese medicine that can effectively ameliorate coronary heart disease- and angina pectoris-related chest congestion and pain. However, the mechanism underlying the therapeutic effects of DLT in the context of stable angina pectoris (SAP) has not been clearly elucidated. In this study, ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was used to analyze serum samples from patients with SAP before and after DLT administration. The results of metabolomic analyses were verified biologically, and the mechanisms of action of DLT with respect to treating SAP were elucidated. Nineteen biomarkers were identified. Among these biomarkers, the levels of 15 reverted to those corresponding to a healthy state following DLT treatment. The main metabolic pathways associated with the functions of DLT in SAP were energy metabolism, purine metabolism, glycerophospholipid metabolism and amino acid metabolism, all of which are related to oxidative stress. Biological verification revealed that DLT decreased the expression of the oxidative stress indicators, xanthine oxidase (XOD) and malondialdehyde (MDA), and increased heme oxygenase-1 (HO-1) expression and superoxide dismutase (SOD) activity. Taken together, we revealed that DLT effectively ameliorates SAP by adjusting the oxidative stress status. This study provided an objective index for evaluating the efficacy of DLT for treating SAP.