Nrf2/Nrf1 luciferase reporter assay

The Nrf2/Nrf1 luciferase reporter assay was performed as described previously using commercial kits. Briefly, L-02 cells were transfected with a Nrf2/1 transcription response element-containing construct using Lipofectamine 3000. After 24 h of transfection, the cells were pre-treated with or without quercetin for 15 min and were then incubated with TSN for the additional indicated time. Luciferase activities were measured using the Duan-Glo Luciferase Assay System, and the constitutively expressed Renilla luciferase was used as an internal control.