Figure 1.

Concentration-dependent effect of resveratrol on HUVECs intracellular ROS levels and redox state. (A) Human umbilical vein endothelial cells (HUVECs) expressing the cytoplasmatic form of the redox-sensing green fluorescent protein (roGFP) were treated for 6 hrs in M199 medium with 5% FCS containing different concentrations of resveratrol (RES) as indicated. After treatment, cells were washed with PBS three times, fixed with 4% paraformaldehyde, counterstained with Hoechst, mounted and visualized by fluorescence microscopy. Images depict cytoplasmic merged photos of roGFP (green) and nuclear Hoechst staining (blue) of cells at 100X magnification. (B) HUVECs expressing the cytoplasmatic form of the roGFP were treated for 24 hrs with the indicated concentrations of resveratrol and then analyzed for the variation of the intracellular redox state as described in materials and methods. (C) HUVECs loaded with the ROS probe H₂DCF-DA were treated for 6 hrs with the indicated concentrations of resveratrol then ROS levels were assessed as described in materials and methods. ctrl: untreated cells; and RFU: relative fluorescence units. Means ± SD of a representative experiment, performed in triplicates, are shown. *, significantly different from the control (p < 0.01).