Protective effects of lindera coreana on UVB-induced oxidative stress in human HaCaT keratinocytes

ABSTRACT

The present study was designed to investigate the protective effect of ethanol extracts from Lindera coreana leaves [LCE] on UVB-induced oxidative stress in HaCaT keratinocytes. The HaCaT cells were pretreated with LCE for 24 h and then exposed to UVB [20 mJ/cm[2]] for 2 h. UVB significantly decreased the cell viability [p<0.05]. LCE did not exhibit significantly cytotoxic effects and increased the viability of the HaCaT cells in a concentration-dependent manner. To further investigate the protective effects of LCE on UVB-induced oxidative stress in HaCaT cells, the cellular levels of reactive oxygen species [ROS], lipid peroxidation and endogenous antioxidant enzymes, including catalase [CAT], superoxide dismutase [SOD] and glutathione peroxidase [GSH-px], were analyzed. LCE decreased the intracellular levels of ROS and lipid peroxidation and increased the activity of antioxidant enzymes. These results suggest that LCE exerted cytoprotective activity against UVB-induced oxidative stress in HaCaT cells through the inhibition of lipid peroxidation, reduction of ROS levels and stimulation of antioxidant enzymes activities. In addition, LCE also decreased the TNF-alpha, IL[-1]beta and IL-6 levels in UVB-irradiated HaCaT cells