Tanshinone IIA inhibits high glucose‑induced proliferation, migration and vascularization of human retinal endothelial cells.

Diabetic retinopathy is the most universal and severe complication of diabetes mellitus. The primary aim of the present study was to determine whether tanshinone IIA (TSA) has an inhibitory effect on the proliferation, migration and vascularization of human retinal endothelial cells (HREC) under high glucose (HG) conditions and the associated underlying mechanism. It was demonstrated that TSA exhibited a significant inhibitory effect on the proliferation, migration and vascularization of HRECs in a dose‑dependent manner, under conditions of high glucose (25 mM) medium. However, there was no distinct inhibitory effect on HREC proliferation, migration and vascularization under normal glucose (NG, 5.5 mM glucose) conditions. Reverse transcription‑quantitative polymerase chain reaction, western blotting and immunofluorescence experiments were conducted to evaluate the effects of TSA on the expression levels of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule (ICAM)‑1. It was demonstrated that TSA significantly downregulated the expression levels of VEGF and ICAM‑1 in a dose‑dependent manner under HG conditions. Overall, the results of the present study indicate that TSA‑mediated inhibition of proliferation, migration and vascularization in HRECs may be associated with its ability to affect the expression levels of VEGF and ICAM‑1.