Total RNA was extracted at different time points, according to standard procedures. Samples with high-quality RNA were reverse-transcribed to cDNA. The GAPDH gene was selected as the internal reference gene. All primers were synthesized by TaKa-
Ra (Dalian, China). hGAPDH: upstream primer 50-ccagggctgcttttaactc- 30 , downstream primer 50-gctcccccctgcaaatga-30; HO-1: upstream primer 50-ttgccagtgccaccaagttc-30 , downstream primer 50-tcagcagctcctgca actcc-30; UGT1A1: upstream primer 50-tggctgt tcccacttactgcac-30 , downstream primer 50-agggtccgtcagcatgacatc- 30; MRP2, upstream primer 50-cactgttggctttgttctgtcc-30 , downstream primer 50-cagggtgcctcattttcca-30 . QT-PCR amplification was carried out according to the SYBRPremix Ex TapTMII kit instructions and tested with the ABI StepOnePlusTM Real-Time PCR System.