[Protective effects and action mechanism of extract from Tibetan medicine Yajima(Chrysosplenium nudicaule) on mice with intrahepatic cholestasis induced by ANIT].

Chrysosplenium nudicaule,Tibetan name " Yajima",is recorded as an effective medicine for the treatment of liver and gallbladder diseases by Tibetan Pharmacopoeia published in the past dynasties,but its traditional efficacy has not yet been investigated by means of modern pharmacological research methods. In this paper,the protective effect of extract of C. nudicaule(ECN) on liver injury in mice was observed by using the mice model of intrahepatic cholestasis(IC) induced by α-naphthyl isothiocyanate(ANIT) and the possible mechanism by which ECN work as the therapeutic agent was discussed. The results showed that the serum levels of AST,ALT,ALP,DBIL,TBIL and TBA of the model mice were notably reduced in dose-dependent manner(P<0. 01,P<0. 05). The activity of SOD and GSH-Px in the liver homogenate of mice was increased,while the content of MDA was decreased(P<0. 01,P<0. 05).Pathological examination of liver in mice showed that ECN could improve the pathological changes of liver tissue in mice. The mRNA expression level of genes related to bile acid metabolism were detected by RT-PCR and the results suggested that ECN could significantly increase the expression of genes such as BSEP,FXR and MRP2(P<0. 01,P<0. 05),meanwhile significantly reduce the expression of CYP7 A1(P<0. 01,P<0. 05). These results confirmed the protective effect of ECN on intrahepatic cholestasis-induced liver injury in mice,and indicated that the mechanism may be related to activating FXR and its target genes,reducing bile acid synthesis and increasing bile acid excretion. This study provides a modern pharmacological basis for the clinical application of Yajima in Tibetan medicine.