Mechanism of Fructus Aurantii Flavonoids Promoting Gastrointestinal Motility: From Organic and Inorganic Endogenous Substances Combination Point of View

BACKGROUND: Fructus Aurantii (FA) derived from the dried, and unripe fruit of Citrus aurantium L. is one of the commonly used traditional Chinese medicines to treat gastrointestinal motility dysfunction diseases. According to the literature research, FA flavonoids (FAF) are important active ingredients of FA promoting gastrointestinal motility, but the exact material basis and mechanism of action are still not very clear. OBJECTIVE: This experiment was designed to illustrate the material basis of FAF promoting gastrointestinal motility and explore the mechanism of action from an organic and inorganic combination point of view. MATERIALS AND METHODS: In this experiment, high-performance liquid chromatography (HPLC) method was used to analyze the composition and content of FAF. Based on the prominent prokinetic effect of FAF on mice, the mechanism of action was speculated through a combination of HPLC coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) and inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: With the method of HPLC, ten dominating components of FAF including neoeriocitrin, narirutin, rhoifolin, naringin, hesperidin, neohesperidin, neoponcirin, naringenin, hesperetin, and nobiletin accounting for more than 86% of FAF were identified. Combined HPLC-QTOF-MS with ICP-MS, the endogenous substances with difference in the blood of mice were analyzed, in which 4-dimethylallyltryptophan, corticosterone, phytosphingosine, sphinganine, LysoPC (20:4(5Z, 8Z, 11Z, 14Z)), LysoPC(18:2 (9Z, 12Z)), and Ca(2+), Mg(2+), Zn(2+) metal ions had significant changes, involving tryptophan metabolism, corticosterone metabolism, sphingolipid metabolism, and other pathways. CONCLUSION: The results preliminarily elaborated the mechanism of FAF promoting gastrointestinal motility from an organic and inorganic point of view, which provide valuable information for researching and developing new multi-component Chinese medicine curing gastrointestinal underpower associated diseases. SUMMARY: Fructus Aurantii flavonoids are one of the main components of Fructus Aurantii that possess prominent gastrointestinal motility promoting efficacy. The mainly material basis of Fructus Aurantii flavonoids promoting gastrointestinal motility were neoeriocitrin, narirutin, rhoifolin, naringin, hesperidin, neohesperidin, neoponcirin, naringenin, hesperetin, and nobiletin. Fructus Aurantii flavonoids can regulate the content of 4-dimethylallyltryptophan, corticosterone, phytosphingosine, sphinganine, LysoPC (20:4(5Z, 8Z, 11Z, 14Z)), LysoPC.(18:2(9Z, 12Z)) and Ca(2+), Mg(2+), Zn(2+)-metal ions, through tryptophan metabolism, corticosterone metabolism, sphingolipid metabolism, and other pathways to present its gastrointestinal motility promoting efficacy. Abbreviations used: FA: Fructus Aurantii; FAF: Fructus Aurantii flavonoids; HPLC: High performance liquid chromatography; HPLC-QTOF-MS: High performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry; ICP-MS: Inductively coupled plasma mass spectrometry; PCA: Principal components analysis; CG: Control group; FAFLG: Low-dosage group of Fructus Aurantii flavonoids; FAFMG: Middle-dosage group of Fructus Aurantii flavonoids; FAFHG: High-dosage group of Fructus Aurantii flavonoids; DPG: Domperidone group.