7-difluoromethyl-5,4'-dimethoxygenistein, a novel agent protecting against vascular endothelial injury caused by oxidative stress.

1. Genistein is known to protect the vascular endothelium. However, genistein exhibits poor bioavailability, which limits its use in the treatment of cardiovascular diseases. 7-Difluoromethyl-5,4'-dimethoxygenistein (dFMGEN), prepared by the difluoromethylation and alkylation of genistein, is a new active chemical entity. The protective effects of dFMGEN against vascular endothelial injury caused by oxidative stress were investigated in the present study. 2. Human umbilical vein endothelial cells were treated with either genistein (10 micromol/L) or various concentrations of dFMGEN (0.1, 0.3, 1, 3 and 10 micromol/L) for 30 min before exposure to 1 mmol/L H(2)O(2) for 24 h. The generation of reactive oxygen species (ROS) was assessed by fluorescence flow cytometry, the release of lactate dehydrogenase (LDH) was examined by biochemical assay, cell viability was measured by the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide assay, cell apoptosis was detected by flow cytometry and the expression of caspase 3 was examined by western blot analysis. 3. Pretreatment with 0.1, 0.3, 1, 3 and 10 micromol/L dFMGEN decreased the generation of ROS and the release of LDH in H(2)O(2)-exposed vascular endothelial cells, enhanced cell viability in a concentration-dependent manner over the concentration range 0.1-10 micromol/L, suppressed H(2)O(2)-induced apoptosis of vascular endothelial cells and downregulated the expression of caspase 3. The protective effect of 10 micromol/L dFMGEN against oxidative stress-induced endothelial injury was stronger than that of 10 micromol/L genistein. 4. The results of the present study suggest that dFMGEN can protect against vascular endothelial injury caused by oxidative stress.