Objective: To investigate the protective effects and mechanism of Buyang Huanwu Tang (BHT) on vascular endothelial cells (VEC) injured by oxidized low density lipoprotein (ox-LDL)

and compare the effect between drug-containing serum and drug-containing plasma on VEC. Method: The modified BHT-containing serum and plasma were prepared. Human umbilical vascular endothelial cells (HUVECs) were treated with serum and plasma containing modified BHT and incubated with ox-LDL for additional 24 hours for ox-LDL modeling. The cell viability was observed by MTT assay

and cells apoptosis rate was observed by using Hoechst 33258 staining and flow cytometry; meanwhile the levels of nitric oxide (NO)

malondialdehyde (MDA)

and the activity of superoxidedismutase (SOD)

glutathione peroxidase (GPx) were determined to explore the difference in the protective effect between modified BHT-containing serum and plasma on injured VEC. Result: As compared with the blank control group

the percentage of cells death and apoptosis was significantly higher in the model group (P<0.05). As compared with the model group

the percentage of cells death and apoptosis was significantly reduced in modified BHT-containing serum group and plasma group (P<0.05); cell viability was significantly increased(P<0.05); the levels of NO

SOD and GPx were all significantly increased

the level of MDA was significantly reduced (P<0.05). Besides

the percentage of cells death and apoptosis was lower in modified BHT-containing serum group than that in plasma group (P<0.05); however

the level of NO in modified BHT-containing plasma group was significantly higher than that in serum group (P<0.05). Conclusion: The serum and plasma containing modified BHT could prevent VEC from oxidative injury induced by ox-LDL

and the mechanism may be associated with improving the function of endothelial cells

anti-oxidative damage and inhibiting cell apoptosis. The protective effect of modified BHT-containing plasma on VEC was more stronger than the modified BHT-containing serum under certain conditions.