Auraptene was administrated to rats for 28 days by oral gavage in doses of 125 and 250 mg/kg.

HT29 cells were used for activity evaluation. To study the cytotoxicity of auraptene in combination with chemotherapy or ionizing radiation, thiazolyl blue (MTT) assay was used. In this regard, MTT dye (Atocel, Budapest, Hungary) was dissolved in phosphate-buffered saline (PBS; 5 mg/mL) and added to each well (20 μL/well) by the end of treatments. Afterwards, plates were incubated for 4 h at 37°C, and then medium was replaced by DMSO (150 μL/well) to dissolve produced formazan crystals, and finally, optic densities of wells were measured spectrophotometrically at 570 nm using an ELISA plate reader (Awareness Connecticut, USA).