Objective:

2

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

Methods:

2

Q-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.

Results:

2

A 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).

Conclusion:

2

HLJDD ameliorates MAFLD by modulating lipid metabolism through IRE1α/XBP1s signaling pathway

providing pharmacological evidence for its clinical application.