AIMTo study the expression of vascular endothelial growth factor (VEGF) in U937 foam cells and the inhibitory effect of salvianolic acid B and Ginkgo biloba extract in vitro.

METHODSU937 cells were incubated with 80 mg.L-1 oxidized low density lipoprotein (OX-LDL) for 48 h and a macrophage-derived foam cell model was established. The VEGF concentration in the media was determined by ELISA; the VEGF protein expression in cells was measured with immunohistochemistry; the VEGF mRNA level in cells was measured by in situ hybridization; the positive ratio detected by a morphometrical analysis system was used as the amount of the VEGF protein expression and the mRNA level.

RESULTSAfter U937 cells were incubated with OX-LDL, VEGF expression level increased greatly both in the cells and in the media. Salvianolic acid B and Ginkgo biloba extract were shown to remarkably inhibit the increase of VEGF. After treated with 10 micrograms/L-1 salvianolic acid B and Ginkgo biloba extract, the VEGF protein concentration in the media and positive ratio in the cells decreased compared with foam cells. After treated with 10 micrograms.L-1 salvianolic acid B and 100 micrograms.L-1 Ginkgo biloba extract, the VEGF mRNA level decreased measured by in situ hybridization.

CONCLUSIONA high VEGF expression level was determined in U937 foam cells. Salvianolic acid B and Ginkgo biloba extract were found to inhibit VEGF expression significantly in U937 foam cells in vitro.