Lycium barbarum-Derived Polysaccharides Alleviate DNA Damage and Oxidative Stress Caused by Ultraviolet Radiation in Corneal Epithelial Cells

Abstract

Purpose Lycium barbarum polysaccharides (LBPs) have been proven to protect the eyes by inhibiting apoptosis. This study was designed to investigate the effect of LBPs on DNA damage and oxidative stress induced by ultraviolet B (UVB) radiation in human corneal epithelial cells (HCECs). Methods HCECs were divided into a control group, UVB group and UVB + LBP group and treated with varying concentrations of LBP (0, 0.05, 0.1, 0.2, 0.4, 0.8, 1.6 and 3.2 mg/mL). Then, the effects of LBP on the viability and apoptosis of HCECs were detected via MTT assay and flow cytometry. Additionally, the contents of superoxide dismutase (SOD), malondialdehyde (MDA), and reactive oxygen species (ROS) in the cells of each group were measured to evaluate the level of oxidative stress. Results LBP at a concentration of 0.4 mg/mL showed the best effect on promoting the viability and inhibiting the apoptosis of HCECs. Compared with the control group, the UVB and UVB + LBP groups exhibited significantly decreased levels of cell viability and SOD and notably increased apoptosis, MDA, ROS, tail DNA percentage, olive tail moment, p-CHK2, and gamma histone (γH2AX). In contrast to the UVB group, the UVB + LBP group presented notably upregulated levels of cell viability and SOD and downregulated apoptosis, MDA, ROS, tail DNA percentage, olive tail moment, p-CHK2, and γH2AX. Conclusions The optimal concentration of LBP to promote the viability and reduce the apoptosis of HCECs is 0.4 mg/mL. Moreover, LBP can alleviate DNA damage and oxidative stress induced by UVB in HCECs.