Induction of electrophile-responsive element (EpRE)-mediated gene expression by tomato extracts in vitro

► A method was developed to test crude tomato fruit extracts in cell-based bioassays. ► This enables testing extracts in reporter gene assays for beneficial heath effects. ► Induction of EpRE-mediated expression by tomato extracts was the proof of principle. ► Isoprenoid-containing tomato extract did not induce EpRE-mediated gene expression. ► Hydrolysed flavonoid-containing tomato extract induced EpRE-mediated expression.