Abstract
Purpose :
To investigate the efficacy of oral administration of Bacillus derived-superoxide dismutase (SOD) in a murine model of experimental dry eye (EDE)
Methods :
Mice were divided into 7 groups according to treatment: un-treated, EDE, vehicle, topical 0.05% cyclosporine (CsA), oral 2.5mg/kg SOD, oral 5.0mg/kg SOD, and oral 10.0mg/kg SOD. After exposure to desiccating stress for 5 days except for the un-treated group, tear volume, tear film break-up time (TBUT), and corneal fluorescein staining scores (CFS) were measured at 0, 5, and 10 days after treatment. Ten days after treatment, 2’,7’-dichlorodihydrofluorescein diacetate assay (DCF-DA) for reactive oxygen species (ROS) production, enzyme-linked immunosorbent assay for malondialdehyde (MDA) were measured in the cornea, conjunctiva, and lacrimal gland. Flow cytometry for CD4+interferon-γ+ T cells were evaluated in the cornea and conjunctiva. In addition, periodic acid-Schiff staining for conjunctival goblet cells and TUNEL assay for corneal apoptotic cells were performed.
Results :
After 5 and 10 days, treatment groups with topical 0.05% CsA, oral 2.5mg/kg SOD, oral 5.0mg/kg SOD, and oral 10.0mg/kg SOD showed increased tear volume and TBUT, and decreased CFS compared with the EDE and vehicle group. ROS production, MDA for oxidative stress, and corneal apoptosis were decreased in the CsA and 3 concentrations of SOD-treated groups. The number of inflammatory T cells of cornea and conjunctiva was decreased and conjunctival goblet cell density was increased in the treatment groups with topical 0.05% CsA, oral 2.5mg/kg SOD, oral 5.0mg/kg SOD, and oral 10.0mg/kg SOD. In addition, compared to the CsA-treated group, the oral 2.5mg/kg SOD groups showed increased TBUT and decreased inflammatory T cells; the oral 5.0mg/kg SOD groups showed decreased CFS and increased conjunctival goblet cells.
Conclusions :
Oral administration of SOD could improve clinical parameters, oxidative damage, and inflammation in the murine EDE model.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.