Effect of Brazilian propolis on human umbilical vein endothelial cell apoptosis

Brazilian propolis has been widely studied in recent years. Considering the lack of data concerning the effects of Brazilian propolis on human umbilical vein endothelial cells (HUVECs), we examined the effects of ethanol-extracted Brazilian propolis (EEBP) at 12.5, 25 and 50 μg/ml on apoptosis of HUVECs deprived of basic fibroblast growth factor (FGF-2) and serum. A high concentration of the extract induced HUVEC apoptosis at 24 h. Furthermore, we investigated the molecular mechanisms of HUVEC apoptosis induced by EEBP by testing the levels of integrin β4, p53, reactive oxygen species (ROS) and mitochondrial membrane potential. A low concentration of EEBP (12.5 μg/ml) could decrease the expression of integrin β4, p53 and ROS levels, whereas high concentrations (25 and 50 μg/ml) could increase the levels of integrin β4, p53 and ROS at 24 h and depress mitochondrial membrane potential level at all times. Considering the doses and the results obtained in this study, Brazilian propolis at high concentrations may be an apoptosis-inducing agent associated with the signal pathway mediated by integrin β4, p53, ROS and mitochondrial membrane potential, thus, propolis should be used in safer levels for human health.