Geniposidic acid protected against ANIT-induced hepatotoxity and acute intrahepatic cholestasis, due to Fxr-mediated regulation of Bsep and Mrp2.

Geniposidic acid (GPA) is the main constituent of Gardenia jasminoides Ellis (Rubiaceae), which has long been used to treat inflammation, jaundice and hepatic disorders. The cholagogic effect of Gardenia jasminoides Ellis (Rubiaceae) and GPA have been widely reported, but the underlying occurrence mechanism remains unclear. This investigation was designed to evaluate the hepatoprotection effect and potential mechanisms of GPA derived from Gardenia jasminoides Ellis (Rubiaceae) on fighting against α-naphthylisothiocyanate (ANIT) caused liver injury with acute intrahepatic cholestasis. Sprague-Dawley (SD) rats were intragastrically (i.g.) administered with the GPA (100, 50 and 25mg/kg B.W. every 24h) for seven consecutive days, and then they were treated with ANIT (i.g. 65mg/kg once in the 5th day) which induced liver injury with acute intrahepatic cholestasis. Serum and bile biochemical analysis, bile flow rate and liver histopathology were measured to evaluate the protective effect of GPA fight against ANIT treatment. The protein and mRNA expression levels of farnesoid X receptor (Fxr), bile-salt export pump (Bsep), multidrug resistance associated protein2 (Mrp2), were evaluated to study the effect of liver protection about GPA against ANIT induced hepatotoxicity and underlying mechanisms. Some abnormalities were observed on ANIT treated rats including weight loss, reduced food intake and hair turned yellow. Obtained results demonstrated that at dose 100 and 50mg/kg B.W. (P<0.01) and 25mg/kg B.W. (P<0.05) of GPA pretreated dramatically prevented ANIT induced decreased in bile flow rate. Compared with ANIT treated group, the results of bile biochemical parameters about total bile acid (TBA) was increased by GPA at groups with any dose (P<0.01), glutathione (GSH) was increased significantly at high dose (P<0.01) and medium dose (P<0.05), total bilirubin (TB) was increased at high and medium dose (P<0.05), direct bilirubin (DB) was only increased at high dose (P<0.01). Serum levels of glutamic-Oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), γ-glutamyltranspeptidase (γ-GT), TB, DB and TBA in comparison with ANIT treated group (P<0.01) were reduced by GPA (between 100 and 50mg/kg B.W.) pretreatment. Histopathology of the liver tissue showed that pathological damages and hepatic portal area filled with bile were relieved after GPA pretreatment compared with ANIT treated group. The protein and mRNA expression of Fxr, Bsep and Mrp2 were decreased in ANIT treated group. On the contrary, the protein and mRNA of Fxr, Bsep and Mrp2 were up regulated significantly pretreatment by GPA at dose of high and medium groups. On protein level of Bsep and Mrp2 the result shown no statistical difference in GPA (25mg/kg B.W.), but it was not same shown in mRNA level. The results of this investigation have demonstrated that the GPA exerts a dose dependent hepatoprotection effect on ANIT induced liver damage with acute intrahepatic cholestasis in rats, which may due to Fxr mediated regulation of bile transporters like Bsep and Mrp2.

Chen H ，Huang X ，Min J ，Li W ，Zhang R ，Zhao W ，Liu C ，Yi L ，Mi S ，Wang N ，Wang Q ，Zhu C ... -  《-》

Geniposide attenuates ANIT-induced cholestasis through regulation of transporters and enzymes involved in bile acids homeostasis in rats.

Geniposide (GE) is one of the major iridoid glycosides isolated from the fruit of Gardenia jasminoides Ellis that has been used to treat hepatic disorders including cholestasis. However, the underlying mechanisms for GE ameliorating the reduction in bile acids accumulation by α-naphthylisothiocyanate (ANIT) remain unclear. The purpose of this study is to characterize the efficacy of GE in regulation of bile acids uptake, synthesis, metabolism, and transport in ANIT-induced rats. Sprague-Dawley rats were orally administrated with vehicle, GE (25, 50, and 100mg/kg), and ursodeoxycholic acid (UDCA) (60mg/kg) once daily for seven days. On the fifth day, a single dose of ANIT (75mg/kg) was administrated via oral gavage. Blood biochemical determination, bile flow rate and liver histopathology were measured to evaluate the protective effect of GE. The mRNA expressions and protein levels of transporters and enzymes involved in bile acids homeostasis were determined by quantitative real-time polymerase chain reaction (PCR) and western blot to study the underlying mechanism of GE against ANIT-induced rats. GE (25, 50, and 100mg/kg, po) dose-dependently prevented ANIT-induced changes in serum markers for liver injury. GE treatment reduced basolateral bile acids uptake via repression of OATP2 (P<0.05). Bile acids biosynthesis was decreased through down-regulation of CYP7A1, CYP8B1, and CYP27A1 (P<0.05). GE significantly increased canalicular bile acids secretion via BSEP (P<0.05), subsequently stimulating bile flow during cholestasis. GE also markedly enhanced mRNA level of basolateral transporter OSTβ (P<0.01). Bile acids transported to the plasma were cleared into the urine, resulting in down-regulation of plasma bile acids. However, GE did not alter the mRNA levels of CYP3A2, UGT1A1 and SULT2A1. Furthermore, the gene and protein expression analysis demonstrated activation of FXR, PXR, and SHP after GE administration. GE attenuates ANIT-induced hepatotoxicity and cholestasis in rats, due to regulation enzymes and transporters responsible for bile acids homeostasis.

Wang L ，Wu G ，Wu F ，Jiang N ，Lin Y ... -  《-》

[Effect of geniposidic acid on hepato-enteric circulation in cholestasis rats through Sirt1-FXR signaling pathway].

Chen H ，Li J ，Hu L ，Zhao W ，Yu H ，Liu HZ ，Ma ST ... -  《-》

Alisol B 23-acetate protects against ANIT-induced hepatotoxity and cholestasis, due to FXR-mediated regulation of transporters and enzymes involved in bile acid homeostasis.

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.

Meng Q ，Chen XL ，Wang CY ，Liu Q ，Sun HJ ，Sun PY ，Huo XK ，Liu ZH ，Yao JH ，Liu KX ... -  《-》

Picroside II alleviates liver injury induced by alpha-naphthylisothiocyanate through AMPK-FXR pathway.

Alpha-naphthylisothiocyanate (ANIT) is a typical hepatotoxicant that causes cholestasis, which causes toxic bile acid accumulation in the liver and leads to liver injury. Picroside II (PIC), one of the dominant effective components extracted from Picrorhiza scrophulariiflora Pennell, exhibits many pharmacological effects. However, the role of AMP-activated protein kinase (AMPK)-Farnesoid X receptor (FXR) pathway in the hepatoprotective effect of PIC against ANIT-induced cholestasis remains largely unknown. This study aimed to investigate the mechanisms of PIC on ANIT-induced cholestasis in vivo and in vitro. Our results showed that PIC protected against ANIT-induced liver injury in primary mouse hepatocytes, and decreased serum biochemical markers and lessened histological injuries in mice. ANIT inhibited FXR and its target genes of bile acid synthesis enzymes sterol-12α-hydroxylase (CYP8B1), and increase bile acid uptake transporter Na + -dependent taurocholate transporter (NTCP), efflux transporter bile salt export pump (BSEP) and bile acid metabolizing enzymes UDP-glucuronosyltransferase 1a1 (UGT1A1) expressions. PIC prevented its downregulation of FXR, NTCP, BSEP and UGT1A1, and further reduced CYP8B1 by ANIT. Furthermore, ANIT activated AMPK via ERK1/2-LKB1 pathway. PIC inhibited ERK1/2, LKB1 and AMPK phosphorylation in ANIT-induced cholestasis in vivo and in vitro. AICAR, an AMPK agonist, blocked PIC-mediated changes in FXR, CYP8B1 and BSEP expression in vitro. Meanwhile, U0126, an ERK1/2 inhibitor, further repressed ERK1/2-LKB1-AMPK pathway phosphorylation. In conclusion, PIC regulated bile acid-related transporters and enzymes to protect against ANIT-induced liver injury, which related to ERK1/2-LKB1-AMPK pathway. Thus, this study extends the understanding of the anti-cholestasis effect of PIC and provides new therapeutic targets for cholestasis treatment.

Li T ，Zheng R ，Xu L ，Zhou M ，Wang X ，Guo Q ，Ji H ，Li L ... -  《-》