Inhibition of MNNG-induced JNK activation by MNNG in the presence of curcumin.

C2C12 cells were treated or not with 70 μmol/L MNNG for 1 hour; 30 μmol/L curcumin was added to the medium 30 minutes before the addition of MNNG. JNK activity was determined by immunoprecipitation of JNK1 from WCE, followed by kinase assay using the substrate GST-cJun.1-79 Bottom panel: Western blotting showing total JNK1 amount present in each cell extract (30 μg/lane).