目的：探讨丁香酚对镰刀菌(F.solani)诱导的小鼠真菌性角膜炎(FK)的保护作用，并初步探讨可能的潜在机制。

方法：采用改良的表层镜法制备FK小鼠模型。二甲基亚砜(DMSO)组大鼠右眼结膜囊涂抹等量DMSO(0.05%)。丁香酚组将丁香酚(160 μg/mL)涂抹至小鼠右眼结膜囊。类胰岛素生长因子-1(IGF-1)组除施用丁香酚外，还于右眼结膜囊涂抹PI3K/AKT通路激活剂IGF-1(10 nmol/mL)。分别在接种镰刀菌悬浮液的第1、3、5 d，于裂隙灯显微镜下观察角膜形态。采用苏木精伊红(HE)染色评估角膜组织病理损伤。测定角膜组织载菌量。酶联免疫吸附试验和蛋白免疫印迹用于分析炎症介质白介素-6(IL-6)和白介素-1β(IL-1β)的水平和PI3K/AKT通路蛋白的表达。

结果：丁香酚治疗可改善FK小鼠的角膜炎形态症状和炎症反应，减轻角膜病理组织损伤和真菌负荷。在镰刀菌感染3 d，与DMSO组相比，丁香酚组角膜组织IL-6水平明显升高，而IL-1β水平明显降低(均P<0.05)； 且丁香酚组角膜组织IL-6水平明显高于IGF-1组、IL-1β水平明显低于IGF-1组(均P<0.05)。在感染5 d，丁香酚组角膜组织中IL-6和IL-1β水平均明显低于DMSO组和IGF-1组(P<0.05)。与DMSO组相比，丁香酚组角膜组织中p-PI3K和p-Akt表达均明显降低(P<0.05)； 且丁香酚组角膜组织p-PI3K和p-Akt表达明显低于IGF-1组(均P<0.05)。

结论：丁香酚可能通过抑制PI3K/AKT通路来减轻镰刀菌引起的角膜炎症，对小鼠镰刀菌角膜炎具有保护作用。

METHODS: A modified epifluorescence microscopy method was used to prepare the FK mouse model. An equal amount of DMSO(0.05%)was applied to the conjunctiva of the right eye of rats in the dimethyl sulfoxide(DMSO)group. The eugenol group was prepared by applying eugenol(160 μg/mL)to the conjunctival sac of the right eye of mice. The insulin-like growth factor-1(IGF-1)group was coated with the PI3K/AKT pathway activator IGF-1(10 nmol/mL)in the conjunctival sac of the right eye in addition to the administration of eugenol. The corneal morphology was observed under a slit-lamp microscope on days 1, 3, and 5 of inoculation with F.solani suspension, respectively. Hematoxylin eosin(HE)staining was used to assess corneal histopathological damage. The bacterial load of corneal tissue was determined. Enzyme-linked immunosorbent assay and Western blot were used to analyze the levels of inflammatory mediators interleukin-6(IL-6)and interleukin-1β(IL-1β)and the expression of PI3K/AKT pathway proteins.

RESULTS: Eugenol treatment improved the morphological symptoms of keratitis and inflammatory response in FK mice, and reduced corneal pathologic tissue damage and fungal load. At 3 d after F.solani infection, corneal tissue IL-6 levels were significantly higher and IL-1β levels were significantly lower in the eugenol group compared with the DMSO group(both P<0.05); corneal tissue IL-6 levels were significantly higher and IL-1β levels were significantly lower in the eugenol group than in the IGF-1 group(both P<0.05). At 5 d after infection, both IL-6 and IL-1β levels in corneal tissue of the eugenol group were significantly lower than those of the DMSO and IGF-1 groups(P<0.05); compared with the DMSO group, the expression of p-PI3K and p-Akt in the corneal tissues of the eugenol group was significantly reduced(P<0.05); the expression of p-PI3K and p-Akt in corneal tissues was significantly lower in the eugenol group than that of the IGF-1 group(both P<0.05).

CONCLUSION: Eugenol may attenuate F.solani-induced corneal inflammation by inhibiting the PI3K/AKT pathway, and it has a protective effect against F.solani keratitis in mice.