Discovery of quality markers of Phyllanthus emblica by integrating chromatographic fingerprint, serum pharmacochemistry and network pharmacology

Phyllanthus emblica (P. emblica) is a vital medicinal plant with both medical and edible values. In the quality standard of P. emblica listed by the Chinese Pharmacopoeia, gallic acid is used as the index component for the content determination. However, a large number of tannin components can be decomposed into gallic acid during its refluxing extraction process, thus affecting the accuracy and specificity of the content determination. Thus, the index component used for the quality control needs to be further determined. In this study, the quality markers of P. emblica was specified by integrating chromatographic fingerprint, serum pharmacochemistry and network pharmacology. The chromatographic fingerprint of 18 batches of P. emblica samples were established by ultra-high-performance liquid chromatography (UPLC), and 8 differential components causing quality fluctuation were identified by chemometric analysis and UPLC-Q-TOF/MS analysis. Afterwards, 14 prototype migration components absorbed into the blood after gavage administration to rats were identified by UPLC-Q-TOF/MS analysis. Subsequently, a network pharmacology approach was used to construct the component-target-disease-pathway network, resulting in the identification of 22 components responsible for efficacy of P. emblica. Finally, by integrating the above results, ellagic acid was screened out as one of the Q-markers and could be employed as a quantitative component of P. emblica to improve the quality standard. The strategy is also informative for discovering Q-markers of other TCMs.