Preventive effects of administered resveratrol in Rh1, Rh30, HT29 and HeLa cells on IGF-1-induced inhibition of PTEN and activation of Akt. Serum-starved Rh1, Rh30, HT29 and HeLa cells were treated with resveratrol (0–100 μM) for 4 h, followed by stimulation with/without IGF-1 (10 ng/ml) for 1 h. (a) Total cell lysates were subjected to Western blotting using indicated antibodies. The blots were probed for β-tubulin as a loading control. Similar results were observed in at least three independent experiments. (b) The blots for p-PTEN, p-Akt (Ser473), and p-Akt (Thr308) were semi-quantified using NIH image J. Results are presented as mean ± SEM (n = 3). a
p< 0.05, difference with control group; b
p < 0.05, difference with IGF-1 group.