Fig. 6

Stigmasterol enhances the efficacy of cisplatin through TET1-mediated hydroxymethylation via the Nrf2 signaling pathway. Nrf2-ARE activity assay was performed by luciferase activity determination after stigmasterol treatment with indicate dose. *p < 0.05 compared with control (a). Western blot was used to estimate the effect of stigmasterol on Tet1 expression (b). Dot-blot assay results of EC cells with stimasterol treatment (c). Full length of Tet1 plasmid was tranfected in Ishikawa cells, then stimasterol was used to treat these cells. Western blot was carried out to determine whether tet1 overexpression could block stigmasterol-induced Nrf2 decline (d). CCK-8 was used to detect the effect of stigmasterol and cisplatin on the spec-2 cells with low level of Nrf2 due to stablely transfection with Keap1, *p < 0.05, ** p < 0.01 compared with control (e)