Effects of polydatin and resveratrol on cell growth of growing and differentiated Caco-2 cells. Growing Caco-2 cells ( panel A) and differentiated Caco-2 cells ( panel B) were treated for 24 h with increasing concentrations (0.2-300 μM) of polydatin and resveratrol. The effects on the cell growth were expressed as % inhibition respect to the untreated cells (control). Cell growth was evaluated by the MTT assay as described in Materials and Methods. In the inset was reported the structure of trans-resveratrol and its natural precursor polydatin.