Preliminary Study On The Treatment Mechanism Of Yin-Zhi-Huang Granules To Rat Cholestasis Induced By Estrogen

AimStudy on the treatment mechanism of Yin-Zhi-Huang granules to rat cholestasis induced by estrogenMethodsRat’s intrahepatic cholestasis was induced by estradiol benzoate (EB,5mg/kg/d) via subcutaneous injection for5days, The successfully established experimental intrahepatic cholestasis rats models were randomly divided into7groups, one of them was Model group and other groups were interfered with saline and Yin-Zhi-Huang granules via oral administration for7,14and21days, respectively, no special treatment was required for the Normal group. Then rats were evaluated through comparing bile flow velocity, bile flow volume, biochemical indicator of blood serum, hepatic pathology, immunohistochemistry and western blot.Results1. Bile flow experiment: After having been given EB daily subcutaneous injection for5days, bile flow velocity and bile flow volume were decreased compared with Normal group (P<0.05). After saline intervening for7,14and21days, compared with Model group, bile flow velocity and bile flow volume were on the rise, but there was no significant difference. After Yin-Zhi-Huang granules intervening for7,14and21days, bile flow velocity and bile flow volume were on the rise and they were significantly increased (P<0.05) at14and21days compared with the same day’s in Saline group.2. Serum biochemical indexes:Compared with Normal group, serum biochemical indexes were on the rise in Model group, the direct bilirubin and total bile acid was significantly increased (P<0.05). After saline intervening for7,14and21days, compared with Model group, there was no significant difference in7days (P>0.05), serum biochemical indexes were on the rise in14days and the the direct bilirubin and total bile acid was significantly increased (P<0.05). It showed a downward tendency at21days and the total bile acid was significantly decreased (P<0.05). After Yin-Zhi-Huang granules intervening for7,14and21days, compared with the same day’s Saline group, serum biochemical indexes had very marked drop trends, the the direct bilirubin and total bile acid were significantly decreased (P<0.05) at14days, there were no significant differences (P>0.05) at7and21days.3. Liver HE staining: The hepatic tissue structure was normal in Normal group. After EB daily subcutaneous injection for5days, compared with Normal group, there were a small number of bile duct hyperplasia, venous congestion, partial hepatocytes necrosis, and inflammatory cell infiltration in rat liver. After saline intervening for7,14and21days, compared with Model group, the lesions showed a continuous aggravating trend from7to14days, it showed a remission trend at21days. After Yin-Zhi-Huang granules intervening for7,14and21days, the hepatic lesion was much more alleviative than the same day’s Saline group, even recovered to normal at21days.4. Immunohistochemistry showed that the transporter Mrp2, Oatp2, Bsep and Ntcp were all expressed in the liver cell membrane in each group, there was no internalization.5. Western-blot experiment:Compared with Normal group, the expression of the hepatic Oatp2, Ntcp, Bsep and Mrp2were all significantly decreased (P<0.05). After saline intervening for7,14and21days, compared with Model group, the expression of the transporter Bsep and Mrp2were on the rise, and there was significantly difference at7and14days, the expression of Oatp2had no significant differences (P>0.05) at7and21days, but significantly decreased (P<0.05) at14days, the expression of Ntcp had no significant differences (P>0.05) at7and14days, but significantly increased (P<0.05) at21days. After Yin-Zhi-Huang granules intervening for7,14and21days, compared with the same day’s Saline group, no significant differences was observed in expression of Bsep (P>0.05), the expression of Mrp2had no significant differences (P>0.05) at14days, but significantly increased (P<0.05) at7and21days, the expression of Oatp2and Ntcp had no significant differences (P>0.05) at7days, but significantly increased (P<0.05) at14and21days.ConclusionThe mechanism of Yin-Zhi-Huang granules on treatment of rat intrahepatic cholestasis induced by estrogen may be associated with the up-regulated expression of the hepatic transporter Oatp2, Ntcp and Mrp2. In addition, it may also relate with the body’s compensatory mechanism on the up-regulated expression of Bsep.