alisol-b-monoacetate and Chemical-and-Drug-Induced-Liver-Injury

Intrahepatic cholestasis is a clinical syndrome with systemic and intrahepatic accumulation of excessive toxic bile acids that ultimately cause hepatobiliary injury. Appropriate regulation of bile acids in hepatocytes is critically important for protection against liver injury. In the present study, we characterized the protective effect of alisol B 23-acetate (AB23A), a natural triterpenoid, on alpha-naphthylisothiocyanate (ANIT)-induced liver injury and intrahepatic cholestasis in mice and further elucidated the mechanisms in vivo and in vitro. AB23A treatment dose-dependently protected against liver injury induced by ANIT through reducing hepatic uptake and increasing efflux of bile acid via down-regulation of hepatic uptake transporters (Ntcp) and up-regulation of efflux transporter (Bsep, Mrp2 and Mdr2) expression. Furthermore, AB23A reduced bile acid synthesis through repressing Cyp7a1 and Cyp8b1, increased bile acid conjugation through inducing Bal, Baat and bile acid metabolism through an induction in gene expression of Sult2a1. We further demonstrate the involvement of farnesoid X receptor (FXR) in the hepatoprotective effect of AB23A. The changes in transporters and enzymes, as well as ameliorative liver histology in AB23A-treated mice were abrogated by FXR antagonist guggulsterone in vivo. In vitro evidences also directly demonstrated the effect of AB23A on FXR activation in a dose-dependent manner using luciferase reporter assay in HepG2 cells. In conclusion, AB23A produces protective effect against ANIT-induced hepatotoxity and cholestasis, due to FXR-mediated regulation of transporters and enzymes.

Topics: 1-Naphthylisothiocyanate; Animals; Bile Acids and Salts; Chemical and Drug Induced Liver Injury; Cholestasis, Intrahepatic; Cholestenones; Cytoprotection; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation, Enzymologic; Hep G2 Cells; Homeostasis; Humans; Liver; Male; Membrane Transport Proteins; Mice, Inbred C57BL; Protective Agents; Receptors, Cytoplasmic and Nuclear; Signal Transduction; Time Factors; Transfection

Carbon tetrachloride (CCl4)-induced hepatotoxicity is a common syndrome with simultaneous severe hepatocyte death and acute cholestasis. The purpose of the present study is to investigate the hepatoprotective effect of alisol B 23-acetate (AB23A), a natural triterpenoid from edible botanical Rhizoma alismatis, on acute hepatotoxicity induced by CCl4 in mice, and further to elucidate the involvement of farnesoid X receptor (FXR), signal transducers and activators of transcription 3 (STAT3) in the hepatoprotective effect. H&E staining, BrdU immunohistochemistry and TUNEL assay were used to identify the amelioration of histopathological changes, hepatocyte proliferation and apoptosis. Real-time PCR and western blot assay were used to elucidate the mechanisms underlying AB23A hepatoprotection. The results indicated that AB23A treatment in a dose-dependent manner resulted in protection against hepatotoxicity induced by CCl4via FXR activation. Through FXR activation, AB23A promoted hepatocyte proliferation via an induction in hepatic levels of FoxM1b, Cyclin D1 and Cyclin B1. AB23A also reduced hepatic bile acids through a decrease in hepatic uptake transporter Ntcp, bile acid synthetic enzymes Cyp7a1, Cyp8b1, and an increase in efflux transporter Bsep, Mrp2 expression. In addition, AB23A induced the expression of STAT3 phosphorylation, and STAT3 target genes Bcl-xl and SOCS3, resulting in decreased hepatocyte apoptosis. In conclusion, AB23A produces a protective effect against CCl4-induced hepatotoxicity, due to FXR and STAT3-mediated gene regulation.

Topics: Alanine Transaminase; Alisma; Animals; Apoptosis; Aspartate Aminotransferases; ATP Binding Cassette Transporter, Subfamily B, Member 11; ATP-Binding Cassette Transporters; bcl-X Protein; Bile Acids and Salts; Carbon Tetrachloride; Cell Proliferation; Chemical and Drug Induced Liver Injury; Cholestenones; Cholesterol 7-alpha-Hydroxylase; Cyclin B1; Cyclin D1; Forkhead Transcription Factors; Hepatocytes; Liver; Male; Mice; Mice, Inbred C57BL; Phosphorylation; Rhizome; STAT3 Transcription Factor; Steroid 12-alpha-Hydroxylase; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins; Up-Regulation

To investigate protective effects of alisol B 23-acetate (AB23A) against hepatotoxity and cholestasis induced by 17α-ethinylestradiol (EE) in association with farnesoid X receptor (FXR) activation in vivo and in vitro.. The cholestatic liver injury model was established by subcutaneous injections of EE in C57BL/6 mice. Serum biomarkers, bile flow assay and H&E staining were used to identify the amelioration of cholestasis after AB23A treatment. Mice primary hepatocytes culture, gene silencing experiment, real-time PCR and Western blot assay were used to elucidate the mechanisms underlying AB23A hepatoprotection.. AB23A treatment protected against liver injury induced by EE through increasing hepatic efflux and reducing uptake of bile acid via an induction in efflux transporters (Bsep and Mrp2) and an inhibition in hepatic uptake transporter (Ntcp) expression. AB23A also reduced bile acid synthesis through repressing Cyp7a1 and Cyp8b1, and increased bile acid metabolism through an induction in gene expression of Sult2a1. We further demonstrated that the changes in transporters and enzymes, as well as ameliorative liver histology in AB23A-treated mice were abrogated by FXR antagonist guggulsterone in vivo and were abrogated after FXR was silenced in vitro.. AB23A produces protective effects against EE-induced cholestasis, due to FXR-mediated gene regulation.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B, Member 11; ATP-Binding Cassette Transporters; Chemical and Drug Induced Liver Injury; Cholestasis; Cholestenones; Cholesterol 7-alpha-Hydroxylase; Disease Models, Animal; Ethinyl Estradiol; Hepatocytes; Liver Function Tests; Male; Membrane Transport Proteins; Mice, Inbred C57BL; Multidrug Resistance-Associated Protein 2; Multidrug Resistance-Associated Proteins; Organic Anion Transporters, Sodium-Dependent; Primary Cell Culture; Receptors, Cytoplasmic and Nuclear; Steroid 12-alpha-Hydroxylase; Symporters