Abstract
Purpose:
We investigated the effect of quercetin on inflammatory event in corneal alkaline burns rabbits.
Methods:
Corneal neovascularization (NV) was induced by applying an 8-mm filter paper soaked in 1 N NaOH to the right central corneas of rabbits for one minute. Seven days later, the rabbits were randomly divided into three groups: the alkaline burn group (n=4, normal saline instilled four times per day), the 5 mg/mL Que group (n=5, 5 mg/mL quercetin instilled four times per day), and the 10 mg/mL Que group (n=5, 10 mg/mL instilled four times per day). The left eyes were used as controls. On the 10th day after therapy, we investigated the fibrosis, neovascularization (NV), inflammation and structural changes of the cornea using H&E staining, masson’s trichrome staining, immunohistochemistry and RT-PCR.<br />
Results:
The alkaline burn produced significant NV (2.9±0.5) and increased corneal thickness (931.06±39.6 μm). On day 10 after 10 mg/mL quercetin treatment, NV (1.8±0.5) and thickness (626.2±45.6 μm) of the cornea were markedly decreased in the quercetin group (p<0.05). In 5mg/mL Que group, NV was markedly decreased (2.3±0.3, p< 0.05) but corneal thickness was not affected. In addition, the quercetin improved the healing of the cornea following alkaline burn, disrupting the corneal epithelial proliferation and reducing the fibrotic changes of the stroma. The hallmarks of angiogesis and inflammation including VEGF, CD31, MMP9, macrophage, TNFα, ICAM-1, VCAM-1 and IL-1β were significantly induced in the cornea by the alkaline burn, and these expression were also suppressed by quercetin.
Conclusions:
In this study, we demonstrated that quercetin was markedly effective in healing alkali-burned corneas by modulating the corneal opacity, NV, fibrosis and inflammation via blocking the NF-κB. Therefore, quercetin is possible promising material for treatment of ocular surface disease related inflammation.