Huanglian Jiedu Decoction Alleviates Metabolic-Associated Fatty Liver Disease in vivo and in vitro via IRE1α/XBP1s Signaling Pathway.

objectiveTo investigate therapeutic effects of Huanglian Jiedu Decoction (HLJDD) on metabolic-associated fatty liver disease (MAFLD) and explore its underlying mechanisms.

methodsQ-Orbitrap liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the incoming blood compounds of HLJDD. In vivo, high-fat diet (HFD)-induced MAFLD rats received HLJDD (5.4, 2.7, 1.35 g/kg) or silybin (37.8 mg/kg) once daily for 6 weeks. The rats fed with normal diets were served as control. Serum lipids were biochemically determined; and hepatic steatosis and lipid accumulation were evaluated with H&E and Oil red O stainings. In vitro, palmitic acid (PA)-treated HepG2 cells were co-incubated with 10% HLJDD drug-containing serum. Intracellular triglyceride (TG), total cholesterol (TC) and nonesterified fatty acids (NEFA) levels were detected and lipid droplet changes in HepG2 cells were observed by Oil red O staining. RT-qPCR and Western blot were employed to assess the expressions of lipid metabolic-related genes [diacylglycerol acyltransferase 2 (DGAT2), stearoyl-coenzyme A desaturase 1 (SCD1)] and components of the inositol-requiring enzyme 1alpha/X-box-binding protein-1 spliced (IRE1α/XBP1s) signaling pathway.

resultsA total of 43 active compounds of HLJDD were identified. In HFD-fed rats, HLJDD treatment significantly improved hepatic TG and TC and increased HDL-C level (P<0.05 or P<0.01), and also markedly reduced serum levels of TG, TC, LDL-C, ALT, and AST (P<0.05 or P<0.01). H&E and Oil red O stainings further revealed that HLJDD effectively alleviated hepatic steatosis and attenuated lipid accumulation in the liver tissues. In PA-treated HepG2 cells, HLJDD treatment significantly reduced intracellular levels of TG, TC, and NEFA (P<0.05 or P<0.01), as well as lipid accumulation. More importantly, HLJDD treatment exerted therapeutic effects in both HFD-fed rats and PA-induced HepG2 cells by down-regulating lipid metabolic-related genes DGAT2, SCD1 and suppressing the IRE1α/XBP1s pathway related protein expressions (P<0.05 or P<0.01).

conclusionHLJDD ameliorates MAFLD by modulating lipid metabolism through IRE1α/XBP1s signaling pathway, providing pharmacological evidence for its clinical application.