Mapping of the GBE-responsive region in human CPT1A promoter region. (A) A promoter fragment of the CPT1A 5’-untranslated region and a schematic representation of the constructed luciferase reporter promoters were presented. (B) Promoter activities of each deletion construct in the absence or presence of GBE in the HepG2 cells. Luciferase activity was presented as a fold induction relative to pGL3-basic vector whose value was set as 1. *P < 0.05 versus each respective control group (DMSO, D). #P < 0.05 versus DMSO treated group of pGL3-basic vector. (C) Regulation of each deletion promoter construct in flavonoid-treated HepG2s. The luciferase activity in each group was calculated as a fold induction relative to the untreated pCPT1A-3/Luc whose value was set as 1. *P < 0.05 and **P < 0.01 versus corresponding untreated construct.