Extract of Moutan radicis cortex and Cinnamomi ramulus ameliorates laser-induced choroidal neovascularization in Brown-Norway rats

•MRCCR is 50% ethanol extract of Moutan radicis cortex and Cinnamomi ramulus (1:1).•Oral MRCCR significantly reduced the choroidal neovascularization by laser injury.•Oral MRCCR significantly reduced the extent of fluorescein leakage by laser injury.•Combining oral MRCCR and intraocular injecting anti-VEGF agent may be more effective.•This combination therapy may reduce the side effects of anti-VEGF agent due to repeated injections. Moutan radicis cortex (MRC) and Cinnamomi ramulus (CR) are commonly used in eastern Asian traditional medicine to treat various diseases including cerebrovascular and cardiovascular, and have wide spectrum of pharmacological activities. However, the effect against laser-induced choroidal neovascularization (CNV) of extract of MRC and CR (1:1) (MRCCR) has not yet been studied. Our aim was to investigate the inhibitory effect of MRCCR on pathological CNV in laser-treated Brown-Norway (BN) rats. MRCCR (60, 90 mg/kg) was orally administered twice per day for 15 days from the day of CNV formation in laser-treated BN rats. Effects of MRCCR or its constituents on cell migration, tube formation, hyperpermeability and phosphorylation of FAK/p38 MAPK were confirmed in humane retinal microvascular endothelial cells or human retinal pigment epithelial cells. MRCCR significantly reduced the CNV lesions areas and the extent of fluorescein leakage. MRCCR and its constituents such as ellagic acid, paeonol or gallic acid decreased cell migration, tube formation or hyperpermeability. MRCCR inhibited the phosphorylation of FAK and p38 MAPK. Combining the oral MRCCR and intravitreal injection of anti-VEGF medicine may result in a more potent therapeutic effect and consequently bring the reduction in eye injection numbers for patients with wet AMD. [Display omitted]