Rosmarinic Acid Suppresses Retinal Neovascularization via Cell Cycle Arrest With Increase of p21WAF1 Expression

Abstract

Purpose: : To investigate whether rosmarinic acid (RA) has an anti-angiogenic activity to retinal neovascularization in a mouse model of ROP, which is related to cell cycle arrest with Increase of p21^WAF1

Methods: : In mice model of oxygen-induced retinopathy with or without intravitreal RA, neovascularization was measured through flourescein angiography using FITC-dextran and blood vessel count in cross section. To determine anti-angiogenic activity of RA to VEGF-induced in vitro angiogenesis, VEGF-induced proliferation and tube formation of retinal endothelial cells was evaluated with RA treatment. In addition, deguelin-induced retinal toxicity was evaluated as well. To investigate whether the anti-angiogenic activity of RA on retinal endothelial cells was related to the cell-cycle arrest, flow cytometry and p21^WAF1 expression was evaluated.

Results: : RA significantly inhibited the proliferation of retinal endothelial cells in dose-dependent manner, and inhibited in vitro angiogenesis of tube formation. Interestingly, the anti-proliferative activity of RA on retinal endothelial cells was related to G₂/M phase cell cycle arrest in a dose-dependent manner. With treatment of RA, retinal endothelial cells in G₂/M phase increased whereas those in G₀/G₁ and S phases decreased, which was accompanied by increase of p21^WAF1 expression in dose-dependent manner. Moreover, RA effectively suppressed retinal neovascularization in a mouse model of ROP, and showed no retinal toxicity.

Conclusions: : Our data suggests RA could be a potent inhibitor of retinal neovascularization and may be applied in the treatment of other vasoproliferative retinopathies.

Keywords: drug toxicity/drug effects • retinal neovascularization • retinopathy of prematurity