Quercetin inhibits vascular endothelial growth factor-induced choroidal and retinal angiogenesis in vitro

The aim of this study was to investigate the effects of quercetin on vascular endothelial growth factor (VEGF)-induced choroidal and retinal angiogenesis in vitro using a rhesus macaque choroid-retinal endothelial (RF/6A) cell line.

RF/6A cells were cultured in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum. Then the cells were treated with different concentrations (from 0 to 100 μM) of quercetin and 100 ng/ml VEGF. The cell proliferation was assessed using cholecystokinin octapeptide dye. The cell migration was investigated by a Transwell assay. The tube formation was measured on Matrigel. Furthermore, the impact of quercetin's effects on VEGF-induced activation of VEGF receptor 2 (VEGFR-2) downstream signal pathways was tested by Western blot analysis.

Quercetin inhibits RF/6A cell proliferation in a dose-dependent fashion: 22.7, 31.5 and 36.7% inhibition on treatment with 10, 50 and 100 μM quercetin, respectively. VEGF-induced migration and tube formation of RF/6A cells were also significantly inhibited by quercetin in a dose-dependent manner. Quercetin inhibits VEGF-induced VEGFR-2 downstream signal pathways of RF/6A.

The results show that quercetin inhibits VEGF-induced cell proliferation, migration and tube formation of RF/6A. We suggest that quercetin inhibits VEGF-induced choroidal and retinal angiogenesis in vitro. Collectively, the findings in the present study suggest that quercetin inhibits VEGF-induced choroidal and retinal angiogenesis by targeting the VEGFR-2 pathway. This suggests that quercetin is a choroidal and retinal angiogenesis inhibitor.