Application of pathways activity profiling to urine metabolomics for screening Qi-tonifying biomarkers and metabolic pathways of honey-processed Astragalus.

Honey-processed Astragalus, a widely used Qi-tonifying and immunomodulating herb in traditional Chinese medicine, has strengthened the tonic effects and achieved fewer side effects compared with astragali radix in clinical application. Here, we focus on Qi-tonifying biomarkers and pathways of honey-processed Astragalus using urine metabolomics that provide the basis for building the linkage between metabolites in rat urine and its symptoms. The spleen Qi deficiency model group, normal group, astragali radix group, and honey-processed Astragalus group were implemented to evaluate Qi-tonifying effects. Twelve potential biomarkers were screened by multivariate statistical analysis by using ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry. Furthermore, pathways activity profiling showed unique pathways that are primarily involved in tryptophan metabolism, tricarboxylic acids cycle, and methionine metabolism. The results demonstrated that metabolomics coupled with pathway activity profiling were promising tools. It might serve as a novel methodological clue to systematically dissect the underlying Qi-tonifying mechanism of honey-processed Astragalus.