Abstract
Purpose :
Ectoine is a natural compound that protects bacterial surviving against extreme environments. This study aimed to explore novel protective effects of ectoine on ocular surface from inflammation using a dry eye mouse model induced by desiccating stress.
Methods :
The experimental dry eye model was created by C57BL/6 mice exposed to desiccating stress (DS). DS mice were topically administrated with ectoine or PBS as vehicles. Clinical signs of corneal epithelial damage were evaluated by corneal smoothness score and Oregon Green Dextran (OGD) fluorescent staining. Pro-inflammatory cytokines and chemokines were assessed to evaluate the ocular surface inflammation by quantitative real-time RT-PCR and immunofluorescent staining.
Results :
Compared with UT mice, corneal epithelial defect was observed as irregularity of corneal smoothness and strong punctate OGD fluorescent staining in DS mice vehicle group. The topical administration of 0.5, 1.0 and 2.0% of ectoine showed protective efficacy on corneal damage at concentration-dependent manner, and ectoine at 1.0 and 2.0% significantly restored the corneal smoothness and reduced OGD staining to near-normal condition. The expression of the ocular surface inflammation related proinflammatory cytokines TNF, IL-1β and IL-6, as well as chemokines CCL3 and CXCL11 by cornea and conjunctiva was dramatically stimulated in DS mice, but inhibited to near or normal levels at mRNA and portion levels after treatment with 1.0 and 2.0% ectoine.
Conclusions :
Our findings demonstrate that ectoine has potential therapeutic efficacy in protecting ocular surface from damage via suppressing pro-inflammatory cytokines and chemokines in a murine model of dry eye disease.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.