Effect of Aralia Elata on the Expression of Hyperosmolarity-induced TonEBP Protein and Inflammatory Mediators in Corneal Epithelial Cells

Abstract

Purpose: To investigate the effect of Aralia elata (AE) on hyperosmolar stress-induced tonicity response enhancer-binding protein (TonEBP) expression and changes in the levels of proinflammatory cytokines in immortalized human corneal epithelial cells (hCECs). Methods: Immortalized hCECs were cultured with either 5 or 10 mu g/mL AE for 24 hours, and the medium then changed to a hyperosmotic medium (500 mOsM/L). After hyperosmolar treatment, cell viability and wound-healing assays were performed, and cell proteins subjected to Western blot analysis, immunocytochemistry for TonEBP and NF-kappa B, and tests measuring changes in the levels of oxidative stress markers and inflammatory mediators. Results: AE pretreatment ameliorated hyperosmolarity-induced cell death and the delay in wound-healing in a dose-dependent manner. AE inhibited TonEBP and phospho-NF-kappa B p65 subunit upregulation. AE significantly decreased the expression levels of Bax, 4-HNE, and IL-1 beta; but increased those of Bcl-2, Bcl-xl, and Gpx. Conclusions: AE increased cell viability and wound-healing, and inhibited the hyperosmolar stress-induced upregulation of TonEBP and NF-kappa B. AE may be useful for treatment of patients with certain ocular surface diseases.