Fig. 1. Curcumin induces HO-1 expression and Nrf2 activation in HaCaT cells. (A) HaCaT cells were treated with various concentrations of curcumin for 1 h (for RNA) or 12 h (for protein). Total RNA and protein were analyzed by RT-PCR (upper panel) and immunoblotting (bottom panel), respectively. (B) HaCaT cells were incubated with 20 μM curcumin for varying times, and total RNA and protein were analyzed by RT-PCR (upper panel) and immunoblotting (bottom panel), respectively. (C) HaCaT cells were incubated with various concentrations of curcumin for 15 min. The nuclear extracts of cells were prepared and the levels of Nrf2 were determined by immunoblotting. (D) Activation of Nrf2 was measured after exposure to 20 μM curcumin for the indicated time. The levels of Nrf2 in the nuclear extracts of cells were determined by immunoblotting.
