Purpose: To determine whether intravitreally-injected baicalin inhibits the growth of choroidal neovascularization (CNV) experimentally induced via laser photocoagulation through analysis of angiogenic factors.
Materials and methods: Six CNVs were induced in the left eyes of 8-week-old male Brown Norway rats. Immediately after the induction of CNV, 4 μl of baicalin solution (0.1, 1 or 5 nmol) and 4 μl of a solution containing 100 μg of bevacizumab were slowly injected into the vitreous cavity under direct observation with an operating microscope. At 14 days after CNV induction, fluorescein angiography (FA) was performed, and choroidal flat mounts were produced for quantitative assessment of CNV. The levels of the anti-angiogenic proteins vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and matrix metalloproteinase-2 (MMP-2) were determined via Western blot analysis.
Results: FA of bevacizumab- and baicalin-treated rats showed significantly reduced CNV and leakage from the CNV lesions compared to control rats at day 14. Choroidal flat mounts revealed that baicalin inhibited the growth of CNV lesions in a dose-dependent manner. Western blot analysis demonstrated that baicalin significantly attenuated the up-regulation of VEGF, PDGF and MMP-2.
Conclusion: Baicalin suppressed laser-induced CNV formation in rats. These results suggest that baicalin should be considered as a candidate drug for treating exudative age-related macular degeneration.
Keywords: Age-related macular degeneration; VEGF; baicalin; choroidal neovascularization; fluorescein angiography.