Garcinone D upregulates AhR (a), Cyp1a1 (b), Nrf2 (c), and HO-1 (d) in HT-29 cells. Cells were treated with 12.5 μM GarD, with 50 μM tBHQ (Nrf2 activator), or with 0.5 μM FICZ (AhR activator) over a 24-h period. Cell lysates were collected and immunoblotted with anti-AhR, anti-Nrf2, anti-HO-1, anti-Cyp1a1, and anti-Actin antibodies; relative protein densities normalized to β-actin. Data are expressed as mean values ± SD from triplicate experiments. Bars bearing * (P ≤ 0.05) and ** (P ≤ 0.01) were significantly different by one-way ANOVA followed by Tukey-HSD test vs control.