IM suppresses the expression of CES1 and CES2 at transcriptional level. (A) HepG2 cells were treated with 2 μM IM for 0, 3, 6, 12 or 24 h, and the mRNA expression of CES1 and CES2 were evaluated by qRT‐PCR. The signals from each target were normalized based on the signal from GAPDH. (B) After the treatment of 2 μM IM for 0, 6, 12, 24 or 48 h in HepG2 cells, the cells lysates were prepared and then analysed by Western blot. (C) Repression of CES1 and CES2 promoter by IM. HepG2 cells were transfected with CES1 promoter reporter (0.64 μg) or CES2 promoter reporter (0.64 μg) along with 0.16 μg of null‐R. reniformis luciferase plasmid. The transfected cells were treated with 2 μM IM. The luciferase activity was evaluated with Dual‐Luciferase Reporter Assay System. The reporter activity was normalized to that of the null‐R. reniformis luminescence signal. Data are expressed as mean ± SEM (n = 5). *P < 0.05, significantly different from control.