Inhibition of irradiation- induced activation of DNA binding of NF-κB by CAPE in vitro and in vivo. Nuclear extracts were isolated and mobility gel shift assays were performed as described in the Material and Methods Section. Representative figures are ahown for (a) A549 cancer cells; (b) WI-38 cells 4 hours after 9 Gy irradiation; and (c) normal mice lung 12 hours after 20 Gy irradiation. These demonstrate the binding activity of nuclear NF-κB is higher in A549 cancer cells. CAPE inhibited the binding activity of NF-κB in A549 cancer cells with or without irradiation and in normal lung cells after irradiation.