PURPOSE:

Recent studies have demonstrated that oxidative stress is involved in the pathogenesis of dry eye disease. Polyols erythritol and glycerin have demonstrated osmoprotective properties in vitro. Evidence indicates these polyols also have antioxidant properties. The purpose of this study was to initiate oxidation in Riken human corneal epithelial cells (R-HCECs) with hydrogen peroxide and evaluate the antioxidant properties of these polyols individually. In addition, a packaging formulation containing these polyols was evaluated in this assay.

METHODS:

R-HCECs were pre-exposed to CellROX Green (CRG) for 30 minutes and then received 0.003– 0.1% hydrogen peroxide (H2O2) to determine an effective concentration needed to initiate CRG oxidation. For antioxidant testing, R-HCECs were preincubated in medium containing a final concentration of 0.9% erythritol and 0.9% glycerin or the packaging formulation containing this concentration of the polyols for 30 minutes. CRG was added with the test articles for 30 minutes and cells were then exposed to 0.006% H2O2 for 3 hours. Fluorescence from oxidized CRG was measured, and integrated responses of the change in relative fluorescent units were analyzed by calculating the area under the curve for each test well over the time course. Cells were assessed for metabolic activity by alamarBlue after completion of the antioxidant assay. 06/12/2024, 16:27

RESULTS:

Exposure of R-HCECs to H2O2 significantly affected cellular metabolic activity, and fluorescence indicated that 0.006% H2O2 was sufficient to initiate significant oxidation of CRG. Cells receiving the test articles and hydrogen peroxide had significantly higher metabolic activity and significantly reduced oxidation of CRG compared with cells receiving 0.006% H2O2.

CONCLUSION:

This in vitro cell model can be used to initiate oxidative stress in R-HCECs and evaluate the antioxidant potential of ingredients in eye care formulations. Both 0.9% erythritol and 0.9% glycerin in combination or the packaging formulation with these polyols exhibit antioxidant activity with human corneal epithelial cells.