RESUMEN
Objective:To explore the therapeutic mechanism of Canhuang tablets on the mRNA and protein expression of farnesoid X receptor (FXR), uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) and multidrug resistance associated protein 2 (MRP2) in the liver of jaundiced rats induced by α-naphthalene isothiocyanate (ANIT). Method:The rats were divided into normal group, model group, Canhuang tablets (CHP) group and ursodeoxycholic acid tablets (UDCA) group. The jaundice model was reproduced by ANIT. After the intervention of the corresponding drugs, the contents of total bilirubin (TBIL), total bile acid (TBA), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in serum and the liver histopathology were examined to evaluate the therapeutic effect of CHP. The relative mRNA and protein expressions of FXR, UGT1A1 and MRP2 in rat liver tissues were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Result:CHP can significantly reduce the increase of TBIL, TBA, ALT, AST and ALP caused by ANIT in rat serum, and inhibit the liver pathological changes, which showed that the removing jaundice effect of CHP was better than UDCA. Compared with the normal group, ANIT significantly inhibited the mRNA levels of FXR, UGT1A1 and MRP2 in rat liver tissues after modeling (P<0.01). Compared with the model group, CHP and UDCA significantly increased the mRNA levels of target genes of each protein after intervention (P<0.01), and CHP was superior to UDCA in improving the mRNA level of bilirubin metabolizing enzyme UGT1A1 (P<0.01). In the aspect of affecting protein expression, compared with the normal group, ANIT modeling significantly increased the expression of FXR in rats (P<0.05). CHP intervention showed a tendency to promote the expression of FXR, while UDCA did not, but there was no significant difference between them. In the aspects of promoting bilirubin metabolism and bile excretion, the expressions of UGT1A1 and MRP2 were significantly decreased by ANIT modeling (P<0.01), while the expressions of UGT1A1 and MRP2 proteins were significantly increased after treatment of CHP (P<0.01). CHP was superior to UDCA in increasing the expression of bilirubin and bile acid efflux protein MRP2 (P<0.01). Conclusion:The jaundice abating mechanism of CHP is related to activating FXR mRNA expression in liver, promoting the mRNA and protein expression of bilirubin metabolizing enzyme UGT1A1 and bile acid transporter MRP2, improving liver metabolism of free bilirubin and promoting bile acid excretion from the liver, and alleviating cholestatic liver injury.
RESUMEN
This study attempts to discuss the correlation between UGT1A1*28 as uridine diphosphate glucuronosyltransferase gene promoter and coding region Gly71Arg gene polymorphism with neonatal hyperbilirubinemia of neonates in Wuhan.A total of 168 neonates were divided into the hyperbilirubinemia group (case group,n=108) and healthy neonates group (control group,n=60).Their DNA was obtained through blood extraction.The gene exon mutation of UGT1A1 was detected by Sanger sequencing,which revealed the relationship between UGT 1A 1*28 and Gly71Arg polymorphism with neonatal hyperbilirubinemia of neonates.The results showed that:(1) The frequency of UGT1Al*28 allele mutation in the case group and the control group was 9.3％ and 10％ respectively,with the difference being not significant between the two groups (P＞0.05).(2) The frequency of Gly71Arg allele mutation in the case group and the control group was 35.1％ and 21.7％ respectively,with the difference being significant between the two groups (P＜0.01).(3) The serum bilirubin level of Gly71Arg mutant homozygous and heterozygous subgroups (n=66) in the case group was 302.7±31.4 μmol/L,which was significantly higher than 267.3±28.5 μmol/L of the wild subgroup (n=42) (P＜0.01).It was suggested that the occurrence of neonatal hyperbilirubinemia of neonates in Wuhan was not associated with UGT 1A1*28 gene polymorphism,but closely with the Gly71Arg gene polymorphism.Meanwhile,the Arg allele mutation was related to the degree of jaundice.