Therapeutic effects of topical 8-oxo-2'-deoxyguanosine on ethanol-induced ocular chemical injury models

Abstract

Purpose:To evaluate the therapeutic effects of topical 8-oxo-2'-deoxyguanosine (8-oxo-dG) on experimental ocular chemical injury models.Methods:We created ocular chemical injury models with 8-week-old BALB/c mice (n = 70) by applying 100% ethanol; the mice were then treated with 8-oxo-dG eye drops 10 and 5 mg/mL and phosphate-buffered saline (PBS) twice daily. After 7 days, clinical findings such as corneal integrity, clarity, and neovascularization were assessed. Histology, immunohistochemistry findings, and inflammatory cytokine levels using real-time polymerase chain reactions in the corneas of the mice were also analyzed.Results:Topical application of 8-oxo-dG eye drops resulted in a significant improvement of epithelial defects and clarity, dose dependently (each P < 0.001). Inflammatory cell infiltration and corneal stromal edema were also decreased in the 8-oxo-dG-treated mice compared with PBS-treated controls, based on hematoxylin and eosin staining. The expressions of F4/80 and neutrophil elastase-positive inflammatory cells and IL-1 and TNF- cytokine levels were significantly reduced in the 8-oxo-dG group compared with the PBS group (each P < 0.01).Conclusions:Topical 8-oxo-dG application showed an excellent therapeutic effect in ocular chemical injury models by suppressing inflammation.