Alisma orientale extract exerts the reversing cholestasis effect by activation of farnesoid X receptor

Abstract

Background: Cholestasis is a clinical syndrome of liver damage that is caused by accumulation of bile acids in the liver and systemic circulation. Farnesoid X receptor (FXR) can regulate synthesis, metabolism, and excretion of bile acids. The rhizomes of Alisma orientale is a well-known traditional Chinese medicine to treat edema, obesity, gonorrhea, leukorrhea, diarrhea, hyperlipidemia, and diabetes in China.

Hypothesis/purpose: We hypothesized Alisma orientale extract (AOE) to exert hepatoprotective effect against α-naphthylisothiocyanate (ANIT) induced cholestasis in rat. We aimed to investigate the mechanism of AOE.

Study design: Male Sprague Dawley rats with intrahepatic cholestasis induced by ANIT were treated with AOE (150, 300, or 600 mg/kg). Rats receiving vehicle (0.5% CMC-Na) served as control.

Methods: 48 h after ANIT administration, rats were sacrificed. Blood was collected to obtain serum and livers were removed for histopathology and protein preparation. Biochemical indicators in serum were determined using commercial kits and triterpenoids were determined by liquid chromatography tandem Qtrap mass spectrometry. Proteomics was analyzed by liquid chromatography tandem ion-trap mass spectrometry. The differently expressed proteins were analyzed via the network database and verified by western blotting. The interaction between triterpenoids and FXR were evaluated by luciferase assay and molecular docking.

Results: AOE treatment significantly decreased the serum AST, ALT, TBIL, and intrahepatic TBA and improved the liver pathologic change induced by ANIT. Proteomics analysis indicated that AOE regulated proteins related to bile acid homeostasis via activating farnesoid X receptor (FXR) signaling pathway. Luciferase assay and molecular docking results indicated that triterpenoids could activate FXR, which resulting in ameliorative accumulation of bile acids in the liver by increase of metabolism and transportation for bile acids, and decrease of synthesis for bile acids.

Conclusion: AOE protected against rat liver injury and cholestasis induced by ANIT by activation of farnesoid X receptor, suggesting that A. orientale could be regarded as a potential hepatoprotective drug.

Keywords: Alisma orientale; Cholestasis; Farnesoid X receptor; Proteomics.