Luteolin reduces the levels of the IGF-IR protein and mRNA in HT-29 cells. (A) HT-29 cells were plated and treated with luteolin as described in Figure 1 for 2 h. Total cell lysates were prepared and immunoblot analyses were conducted. Photographs of the chemiluminescent detection of the blots, which were representative of three independent experiments, were shown. The relative abundance of IGF-IR to their own β-actin was quantified via densitometric scanning of the exposed films, and the control levels were set at 100%. (B)HT-29 cells were plated and treated with luteolin as described in Figure 1 for 2 h. (C)HT-29 cells were treated with 0 or 60 μmol/L of luteolin for 2, 8, and 24 h. (B, C) Total RNA was isolated and real-time PCR was conducted. Each bar represents mean ± SEM (n = 3). (A, B) Means without a common letter differ, P < 0.05. (C) *Different from 0 μmol/L of luteolin at each treatment time, P < 0.05.