Integrated Serum Metabolomics and Biological Network Analysis to Predict the Dryness Mechanisms of Fructus Aurantii and Its Q-Markers of Dryness

Abstract

Background: Fructus aurantii (FA) is the dry immature fruit of the plant Citrus aurantium L. and its cultivated varieties. FA is a medicinal material with the same origin as medicine and food, which can promote qi circulation to alleviate the middle energizer. Clinical practice and life experience have proved that FA has strong dryness, and its dryness is usually regarded as an adverse effect. However, the underlying mechanism has not been clarified to date, which restricts the development and application of it.

Objective: Integrating serum metabolomics and biological network analysis, we investigated the key metabolic pathways and potential targets of FA and its dryness quality markers to produce dryness.

Methods: First, the changes in serum metabolites in each group of mice were detected by UPLC-LTQ-orbitrap-MS metabolomics technology, and the differential metabolites were screened by multivariate statistical analysis. Second, network pharmacology was applied to explore potential targets of dryness of each component of the administered drug. Third, potential pathways and targets were exposed by joint pathway analysis in the MetaboAnalyst 6.0 database, and the “compound-reaction-enzyme-gene” network was constructed with Cytoscape 3.9.1 software. Moreover, key pathways and key genes were screened based on the results of joint pathway analysis and the “compound-reaction-enzyme-gene” network. Last, molecular docking technology was used to verify the combination of each component with the target.

Results: Twelve different metabolites, including ascorbic acid, oxalacetic acid, and so on, were selected in metabolomics. Six cometabolic pathways, including the citrate cycle (TCA cycle) and arachidonic acid metabolism, were identified. It involves eight genes, such as EGFR, SRC, KDR, BCL2, HIF1A, ESR1, MET, and IGF1R, and four metabolites, such as ascorbic acid, oxalacetic acid, D-ribose, and gluconic acid. Three metabolic pathways, TCA cycle, arachidonic acid metabolism, and pentose phosphate pathway, were identified in the metabolite-reaction-enzyme-gene network. The pentose phosphate pathway is a unique metabolic pathway of FA. Molecular docking technology had proved that the four monomers produced dryness by affecting the expression of EGFR, SRC, KDR, MET, and IGF1R.

Conclusion: FA and its Q-markers of dryness affect the citrate cycle (TCA cycle) and arachidonic acid metabolism by regulating eight genes, including EGFR, SRC, KDR, BCL2, HIF1A, ESR1, MET, and IGF1R, and then produce dryness. TCA cycle and arachidonic acid metabolism were identified as the most relevant metabolic pathways. The results suggested that the dryness of FA was caused by the synergistic effect of multicomponent, multitarget, and multipathway. This study laid a foundation for researching the dryness-alleviating effect and mechanism of FA processed and also provided a new idea and direction for the research of dryness in traditional Chinese medicine.