Metabolomics study of the hepatoprotective effect of Phellinus igniarius in chronic ethanol-induced liver injury mice using UPLC-Q/TOF-MS combined with ingenuity pathway analysis

Background: Phellinus igniarius (L.) Quel as a potential medicinal mushroom possesses multiple biological activities including hepatoprotection, but the hepatoprotective mechanism is not clear. Purpose: To elucidate the hepatoprotective effect and potential target of P. igniarius. Methods: The male C57BL/6 mice were fed with the Lieber-DeCarli diet containing alcohol or isocaloric maltose dextrin as control diet with or without P. igniarius decoction (PID) in the dosage of 0.65 g/kg and 2.6 g/kg. The levels of serum biomarkers were detected by an automatic biochemistry analyser. The histopathological changes of liver were observed by hematoxylin and eosin (H&E) staining. Ultra performance liquid chromatography quadrupole/time-of-flight mass spectrometry (UPLC-Q/TOF-MS) was applied for investigating the dynamic changes of serum metabolites in chronic ethanol-induced liver injury mice and after treatment with PID. Ingenuity pathway analysis (IPA) was employed to identify the potential target of PID. Results: PID could significantly reduce the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG) and total bile acid (TBA) in serum and improved hepatic steatosis and inflammation. In terms of metabolism, a total of 36 serum differential metabolites were identified, and PID intervention regulated 24 of them, involving the key metabolic pathways such as the biosynthesis of unsaturated fatty acids, primary bile acid biosynthesis, glycerophospholipid metabolism, fatty acids biosynthesis, ether lipid metabolism and arachidonic acid metabolism. On the mechanism, IPA showed that farnesol X receptor (FXR) was the major potential target for PID, and PID could improve chronic alcohol intake induced by the inhibition of mRNA expression of FXR in the liver and the activation of mRNA expression of FXR in the intestine in mice. Conclusion: The present study for the first time systematically illustrated the hepatoprotective effect of P. igniarius and preliminarily explored its potential target FXR. P. igniarius might be exploited as a promising therapeutic option for alcoholic liver injury.