2.3 Cell transfection and luciferase assay
HEK-293T cells cultured in 96-well plate were transiently transfected with NF-κB-responsive luciferase reporter plasmid using Lipofectamine 3000 transfection reagent. The cells were cultured for 24 h and treated with the compounds together with TNF-α (100 ng/ml) for 6 h. Luciferase activity was determined using luciferase assay kits according to the manufacturer’s instructions.