Hepcidin is decreased by dietary iron deficiency or by curcumin. (A) Hepcidin mRNA was measured by real-time RT-PCR in livers of mice receiving dietary iron ranging from 1000 to 5 mg/kg diet (n = 5). Data were normalized to β-actin mRNA. The decline in hepcidin was statistically significant. (B) Hepcidin was measured in mice receiving 5 mg/kg dietary iron supplemented with different concentrations of dietary curcumin (n = 5). The difference between the 0% and 2.0% dietary curcumin group is of borderline significance compared using a 2-sample t test for specific comparisons (P = .08); other differences were not statistically significant. (C) HepG2 hepatocytes were treated with increasing concentrations of curcumin for 8 hours and hepcidin mRNA measured by real-time RT-PCR. Data were normalized to β-actin mRNA. The decline in hepcidin was statistically significant (P < .001 for trend); 12.5 and 25 μM curcumin were statistically different from control (P ≤ .001); 6.25 μM curcumin was not different from control). (D) Duplicate cultures of HepG2 cells were treated with the indicated concentrations of curcumin for 48 hours, and ferroportin levels assessed by Western blot. GAPDH was used as a loading control.