Determination of metabolic markers for lipid metabolism disorders and liver injury recovery via PXR/FXR-CYP7A1 regulation by Folium Ginkgo

The therapeutic effect of Folium Ginkgo (GK) in treating hyperlipidemia is well known and has been widely investigated. However, a precise and microcosmic biological evidence is lacking to support and validate this effect. To better understand the therapeutic mechanisms of GK, the regulatory activity of the Pregnane X receptor (PXR)/ Farnesoid X receptor (FXR)- Cytochrome P450 family 7 subfamily A polypeptide 1 (CYP7A1) axis was hypothesized as a potential pathway and validated through multiple dimensions, including pharmacology, molecular biology, and metabolomics experiments. We established an hyperlipidemia rat mode, and the body weight, body mass index (BMI), blood lipid levels of the rats were measured. Tissue samples were collected for determining the signaling pathway using quantitative real time polymerase chain reaction and western blot. The obtained plasma/tissue samples were subjected to UPLC-Q-TOF-MS/MS analysis for metabolomic investigation. Key metabolites were selected and their concentrations in serum, liver, kidney were simultaneously determined using UPLC-MS/MS. Metabolomic data were then statistically analyzed and schematics were drawn to illustrate the scientific basis for GK's effects in inhibiting blood stasis and phlegm turbidity. Contributions of the differential metabolites were also evaluated. GK significantly reduced triglyceride (TG) and total cholesterol (TC) levels in hyperlipidemic rats with liver injury, with a more significant decrease observed in TC levels. Liver biopsy results showed that GK outperformed currently available drugs in reducing lipid deposition in hepatocytes. Moreover, GK significantly regulated the expression of key sites on the PXR/FXR axis and influenced lipid metabolism and transport. These findings were corroborated by metabolomic studies, which identified 67 different metabolites. Among them, hippuric acid, choline, hecogenin, arachidonic acid, docosahexaenoic acid, deoxycholic acid, N-acetylserotonin, pantothenic acid, and cholic acid were selected as metabolic markers for PXR/FXR-CYP7A1 regulatory activity. Further investigation of these 9 metabolites revealed their involvement in 13 metabolic pathways, explaining the biological basis of the therapeutic effects of GK on lipid metabolism disorders and related liver injuries.This study provides evidence for the efficacy of GK in alleviating lipid metabolism disorders and associated liver injuries. Furthermore, it identified quantifiable efficacy and disease course evaluation indicators and representative metabolic markers that provide a more systematic and in-depth scientific basis for the traditional Chinese medicine theory underlying the therapeutic effects of GK.