Abstract
Purpose :
To investigate the anti-inflammatory and anti-oxidative effects of Camellia japonica (CJ) on human corneal epithelial (HCE) cells and its therapeutic effects in a mouse model of experimental dry eye (EDE) after topical administration.
Methods :
CJ extracts of varying concentrations (0.001%, 0.01%, and 0.1%) were used to treat HCE cells. Cell viability after treatment with CJ extracts was measured using the EZ-Cytox assay. The effects of CJ extracts on hydrogen peroxide (H2O2)-induced cytotoxicity in HCE cells were also measured. Dichloro-dihydro-fluorescein diacetate (DCF-DA) and dihydroethidium (DHE) assays were to analyze the anti-oxidative property of CJ extracts. Eye drops containing 0.001%, 0.01% or 0.1% CJ extracts, or a balanced salt solution (BSS), were applied to the EDE. Tear volume, tear film break-up time (TBUT), and corneal fluorescein staining scores were measured at 7 days after treatment. Levels of TNF-a, IL-1b, IL-6, IFN-r, CXCL-9, and CXCL-10 were measured with a multiplex immunobead assay. Production of reactive oxygen species (ROS) was also measured in the conjunctiva using the DCF-DA assay.
Results :
The EZ-Cytox assay revealed that CJ extracts of varying concentrations were non-toxic to HCE cells. The viability of H2O2-treated HCE cells showed a significant improvement after pretreatment with 0.01% and 0.1% CJ extracts. In addition, treatment with 0.01% and 0.1% CJ extracts decreased ROS production in HCE cells. Mice treated with 0.1% CJ extracts showed significant improvements in tear volume, TBUT, and corneal fluorescein staining scores compared with the EDE and BSS groups. A significant decrease in the levels of inflammatory cytokines and chemokines was observed in the 0.01% and 0.1% CJ extracts groups. The levels of ROS significantly decreased in the 0.01% and 0.1% CJ extracts groups compared with the EDE and BSS groups.
Conclusions :
CJ extracts improved the cellular viability and decreased ROS production in HCE cells. In addition, CJ extracts could improve clinical signs and reduce inflammatory and oxidative stress markers in EDE, suggesting that topical CJ extracts could be used as a potential treatment agent for dry eye.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.