Abstract
Purpose :
The wet form of age-related macular degeneration (AMD) causes severe visual impairment. Exploring a new intervention is essential to alleviate the progression of AMD. We and others showed that Baicalein, a natural flavonoid, is a potent anti-inflammatory agent. To investigate whether Baicalein is beneficial to AMD, we investigated its effects on choroid inflammation and neovascularization following laser-induced choroidal neovascularization (CNV).
Methods :
Adult C57BL/6 mice were anesthetized with ketamine (120 mg/kg) and xylazine (20 mg/kg), and CNV was induced by rupturing the Bruch’s membrane through laser photocoagulation (a 532 nm laser, 150 mV, 50 ms, 4 spots). Baicalein (100 mM) or vehicle control solution (20% (2-hydroxypropyl)-beta-cyclodextrin) was injected intravitreally immediately after laser injury. At 7 days post injury, retinal angiography was performed by intraperitoneal injection of 2.5% AK-FLUOR to assess vessel leakage. In addition, macrophage infiltration and neovascularization in retinal pigment epithelium-sclera-choroid complex (RSCC) were investigated by immunolabeling of Iba1, iso-lectin and VEGF, respectively. We also examined the effect of Baicalein (10 mM) on vascular endothelial cell tube formation in cultured human endothelial cells.
Results :
Baicalein significantly decreased the spot size (P<0.05) of laser induced CNV and vessel leakage (P<0.01) as shown by retinal angiography and iso-lectin immunolabeling compared to vehicle controls. We observed that Baicalein also significantly decreased the number of Iba-1+ macrophages and the level of VEGF expression in RSCC in vivo and suppressed the endothelial cell tube formation (P<0.05).
Conclusions :
Baicalein is a potent agent that suppresses vessel leakage, inflammation and neovascularization following laser induced CNV. Our data suggest that Baicalein could be a potential therapeutic agent and a complement to the conventional anti-VEGF therapy for AMD.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.