To examine the effect of simvastatin on vascular endothelial growth factor (VEGF) expression in cultured human retinal pigment epithelial (RPE) cells under oxidative stress.

RPE cell viability was measured using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay after 24 hours of incubation with various concentrations of simvastatin or H₂O₂. Cultured human RPE cells were pretreated with various concentrations of simvastatin and then incubated with 100 µm H₂O₂. After 24 hours of incubation, an enzyme-linked immunosorbent assay (ELISA) was performed to evaluate the expression of VEGF.

Simvastatin showed no toxicity up to 10 µm, but cell viability gradually decreased with increased concentration of simvastatin. Human RPE cells showed increased VEGF expression when exposed only to H₂O₂. When RPE cells were preincubated with simvastatin and later exposed to H₂O₂, VEGF expression was relatively lower.

Simvastatin downregulated the expression of VEGF in human RPE cells under oxidative stress. Simvastatin may have some clinical benefits in preventing retinal diseases associated with VEGF.