Untargeted lipidomics analysis of Mori Fructus polysaccharide on acute alcoholic liver injury in mice using ultra performance liquid chromatography-quadrupole-orbitrap-high resolution mass spectrometry

Abstract

Ethnopharmacological relevance: Mori Fructus (MF) is a traditional Chinese medicine with long application history, which has protective effects on liver diseases. Mori Fructus polysaccharide (MFP) is one of the active ingredients of MF and possesses therapeutic effects against acute alcoholic liver injury. Recent researches have reported that the therapeutic effects of MFP might be related to the regulation of several lipid metabolic pathways. However, the mechanism of lipid metabolism was still unclear.

Aim of the study: This study aimed to investigate the regulatory effect of MFP on lipid metabolism in mice with acute alcoholic liver injury, and to enrich the application of its hepatoprotective effect.

Materials and methods: Fifty Specific Pathogen Free (SPF) Kunming (KM) male mice were divided into five groups randomly, including normal control group, model group, bifendate positive group (220 mg/ kg), MFPA1 group (50 mg/ kg) and MFPB1 group (50 mg/ kg). A model of acute alcoholic liver injury was established by treating the mice with ethanol. The liver sections were processed and histopathological changes was observed with hematoxylin and eosin staining. The secretion levels of biochemical indexes in the liver and serum were assayed by ELISA. The untargeted lipidomics analysis was performed on a Q Exactive Focus quadrupole orbitrap high resolution mass spectrometry coupled with a Dionex Ultimate 3000 RSLC (HPG) ultra-performance liquid chromatography (UPLC-Q-Orbitrap-HRMS) system (Thermo Fisher Scientific), with a HESI ionization source.

Results: It was observed that abnormal glutamic-pyruvic transaminase enzyme (ALT), glutamic-oxaloacetic aminotransferase (AST), triglyceride (TG), superoxide dismutase (SOD), and malondialdehyde (MDA) concentrations were ameliorated after irrigation of MFP or bifendate. Histopathology examination showed that intragastric infusion of MFP can be helpful in the repair of damaged liver in mice. The multivariate analysis of hepatic lipids showed segregation of ethanol-fed groups from the normal controls. After the comparison of mass spectra, 10 lipids were found to have different content in the normal control group and the model group. Differential lipids that were increased by ethanol exposure included fatty acids, phosphatidylcholine, and lyso-phosphatidylethanolamine, whereas lyso-phosphatidylcholine decreased. Among them, 4 lipids almost returned to the level of normal mice after MFP treatment.

Conclusion: The therapeutic effect of MFP on acute alcoholic liver injury may be achieved by regulating a variety of metabolic pathways, including linoleic acid metabolism, α - linolenic acid metabolism, and glycerolphospholipid metabolism. These results revealed that MFP efficiently exerted hepatoprotective benefits, and its potential effect was associated with the amelioration of lipid metabolism.

Keywords: Hepatoprotective effect; Lipid metabolism; Mori Fructus polysaccharide; Untargeted lipidomics.