Co-treatment with the BCRP/ABCG2 inhibitor, chrysin, greatly enhances the cytotoxicity of sorafenib in Hep3B and HepG2 HCC cells.

<p>(A-D) HCC cells were pre-treated with 25 µM chrysin for 1 h, followed by sorafenib treatment. Cell viability was examined by using a bright-field imaging assay after 1 day (A), crystal violet staining assay after 1 day (B) and MTT assay after 3 days (C). The expression of the apoptotic marker, cleaved PARP, was examined by Western blot analysis (D).