Alkalies/therapeutic use* ; Burns, Chemical/drug therapy* ; Corneal Injuries/drug therapy* ; Eye Burns/drug therapy* ; Humans ; Taurine

The effect of topically applied 1% sodium hyaluronate (Na-HA) on the healing of a standardized corneal alkali wound was studied. The healing of the epithelium, stroma, and endothelium was evaluated separately, using quantitative methods. Central corneal alkali wound was produced in one eye of the rabbits by applying a 5.5-mm round filter paper, soaked in 1 N NaOH, for 60 seconds. 1% Na-HA in the treatment group and phosphate buffered saline (PBS) in the control group were given topically 4 times per day for 2 days, 1- and 3-weeks. Epithelial and endothelial healing was assessed morphometrically from standardized photographs and micrographs, respectively. Stromal healing was determined by counting polymorphonuclear leukocytes (PMN) and keratocytes in the central and marginal wound areas. A positive healing influence was observed in the epithelium. In stromal healing, 1% Na-HA treated corneas showed less PMNs and more keratocytes than the control group, suggesting that topically applied 1% Na-HA may suppress the stromal PMN infiltration and enhance the keratocyte repopulation during corneal alkali wound healing. However, no significant difference was found in morphometric evaluation of endothelial healing between the two groups.
Administration, Topical ; Animals ; Burns, Chemical/*drug therapy/etiology/pathology ; Cell Count ; Cornea/*drug effects/pathology ; Corneal Stroma/drug effects/pathology ; Endothelium, Corneal/drug effects/pathology ; Epithelium/drug effects/pathology ; Eye Burns/chemically induced/*drug therapy/pathology ; Hyaluronic Acid/administration & dosage/*pharmacology ; Ophthalmic Solutions ; Rabbits ; Sodium Hydroxide/toxicity ; Wound Healing/*drug effects

OBJECTIVETo evaluate the efficacy of epigallocatechin gallate (EGCG) in treatment of corneal alkali burn injury in mice.

METHODSCorneal alkali burn injury was induced by sodium hydroxide method in C57BL/6J mice. The mice with cornea burns were treated intraperitoneally with EGCG solution or phosphate buffer solution (PBS) respectively. The healing of corneal epithelium, the formation of corneal neovascularization (CNV) and the inflammation reaction were assessed by slit -lamp microscopy and histological examination. Expression of vascular endothelial growth factor (VEGF) mRNA and protein in cornea was evaluated by real -time reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively. Myeloperoxidase (MPO) assay was used to quantitatively evaluate the polymorphonuclear neutrophils (PMNs) infiltration in the corneas.

RESULTSThe healing rate of corneal epithelium in EGCG group was significantly higher than that of PBS group at d1, d3 and d7 after treatment (d1: 41.0%±13.0% vs 23.8%±7.6%; d3: 76.6%±7.5% vs 61.2%±6.8%; d7: 87.8%±8.5% vs 74.0%±9.1%; all P <0.05). The CNV scores and the number of CNV in the corneal sections of EGCG group were significantly lower than those of PBS group at d3, d7 and d14 after treatment (CNV score: d3: 1.1±0.5 vs 6.6±1.0; d7: 1.3±0. 3 vs 8.1±1.0; d14: 0.9±0.2 vs 9.2±1.1; CNV number: d3: 1.68±0.61 vs 2.92±0.95; d7: 4.80±1.36 vs 7.92±1.28; d14: 3.64±0.71 vs 5.88±0.76; all P<0.05) . The expression of VEGF protein at d3 (0.19±0.05 vs 0.45±0.08) and d7 (0.42±0.07 vs 0.84±0.09), the expression of VEGF mRNA at d1, d3 and d7 in EGCG group were significantly lower than those in PBS group (all P <0.05). Compared to PBS group, the inflammatory index at d3 (3.2±0.4 vs 3.7±0.5) and d7 (2.3±0.5 vs 4.0±0.0), the number of PMNs in the corneal sections and the MPO values at d3, d7 and d14 in EGCG group were significantly decreased (PMNs: d3: 34.5±15.7 vs 90.0±28.8; d7: 17.1±11.4 vs 54.9±25.9; d14: 12. 8±4.6 vs 39.0±17.9; all P <0.05).

CONCLUSIONIn the murine corneal alkali burn model, intraperitoneal injection of EGCG solution can promote the healing of corneal epithelium, inhibit the formation of CNV and reduce the inflammatory cell infiltration in the corneas.

Alkalies ; Animals ; Burns, Chemical ; drug therapy ; Catechin ; analogs & derivatives ; therapeutic use ; Cornea ; drug effects ; pathology ; Corneal Neovascularization ; prevention & control ; Disease Models, Animal ; Eye Burns ; drug therapy ; Inflammation ; drug therapy ; immunology ; Mice ; Mice, Inbred C57BL ; Neutrophils ; cytology ; RNA, Messenger ; Vascular Endothelial Growth Factor A ; metabolism