Fig. 4.

Activation of signaling molecules in STC-1 cells treated with curcumin, its synthetic analogues and metabolites (all at 20 μM concentration) or phorbol ester (PMA). Treated cells were harvested and protein was resolved by SDS-PAGE followed by blotting on nitrocellulose membrane. (A) The membrane was probed with a primary antibody that recognized a PKC-specific phosphorylated sequence in target proteins. (B, C) Immunoblot detection of phosphorylated and total CaMKii. (D,E) Immunoblot detection of phosphorylated and total ERK. Compounds considered unstable are underlined. The numbers between the phosphorylated and corresponding total or loading control bands indicate their relative intensity. BCP, bicyclopentadione, CG, curcumin-glucuronide, C, curcumin, SE, spiroepoxide, v, vehicle, M, molecular weight marker.