Abstract: To understand the effects of Brazilian propolis on the activity and expression of phosphatidylcholine-specific phospholipase C (PC-PLC) in vascular endothelial cells (VECs) deprived of serum and basic fibroblast growth factor (FGF-2).Confluent cells were deprived of serum and FGF-2,then the cells were divided for treatment by Brazilian propolis 12.5,25 and 50 μg/mL for 24 h.Cell viability was measured by MTT method,the activity of PC-PLC was determined by using L-α-phosphatidylcholine as the substrate,the expression of PC-PLC was tested by immunohistochemistry.Results showed that treatment of Brazilian propolis 25 and 50 μg/mL for 24 h significantly depressed VECs viability,and the activity and expression of PC-PLC were also decreased by high concentration Brazilian propolis.The effects of Brazilian propolis on VECs had dose-dependent,and considering the safety of using Brazilian propolis,more attention should be paid on the concentration of propolis.

Key words: Brazilian propolis, phosphatidylcholine-specific phospholipase C, cell viability