Urinary metabolomics study of Xiangdan submicron emulsions on a rat model of myocardial ischaemia

The aim of this study was to discover the potential biomarkers changes on a rat model of isoproterenol (ISO) induced myocardial ischaemia before and after treatment with a Xiangdan submicron emulsion and to explore the unclearing mechanisms by urinary metabolomics.

Three active traditional Chinese medicine (TCM) ingredients were formulated into a lyophilized submicron emulsion powder with hydroxypropyl-β-cyclodextrin encapsulation by high pressure homogenization technology. The three ingredients were given both separately and combined, and the corresponding effects of the three drugs were compared. Principal component analysis (PCA) and the HPLC-UV analytical method was applied to explore the change of composition of urine metabolites in a rat model of isoproterenol induced myocardial ischaemia.

Analytical methods measuring the three active ingredients in urine samples were established. PCA score plots revealed that the therapeutic effect of the Xiangdan submicron emulsion was more significant than that of the Xiangdan injection. There was a synergistic effect among the three active ingredients. Furthermore, studies of rat metabolism changes and structure analysis of biological markers indicated that the mechanism of Xiangdan formulations was related to the inhibition of abnormal tryptophan metabolism.

Xiangdan preparations had a confirmed effect in the treatment of coronary heart disease, especially with the novel Xiangdan submicron emulsion formulation. Urinary metabolomics methods to monitor special biomarker changes is an excellent method to reveal the mechanism of action of TCM drugs.