Untargeted components and in vivo metabolites analyses of Polygonatum under different processing times

Polygonatum is a medicinal and edible homologous food, for which nine steaming and nine drying (SAD-9) is the most used processing method. The processed polygonatum not only changes its components, but also causes the fluctuation of metabolites in vivo. UPLC-QTOF/MS (Ultraperformance liquid chromatography-Quadrupole time of flight mass spectrometry) was employed to analyze the changes in components and the plasma untargeted metabolomics, thus, the differences in vitro of three groups of polygonatum (Raw Polygonatum, RP; two steaming and two drying, SAD-2; nine steaming and nine drying, SAD-9) and their effects on metabolic fluctuations in vivo were revealed. Results showed that the components, such as protein, fat, polysaccharide, flavonoids, saponins and isoflavones changed after processing. Moreover, 4 types of Lysophosphatidylcholines, the major differential metabolites, were highly expressed in rats' plasma of SAD-9 group. Furthermore, through network pharmacological analysis, it was found that liquiritigenin and 4′,5-dihydroxyflavone activated PLA2 type enzymes to promote the production of lysophosphatidylcholine, and the processing method of SAD-9 was conducive to the role of these two components. These findings indicated the dissimilarity of components and metabolic profiles of polygonatum under different processing times, and revealed the advantages of SAD-9 processing methods.