Protective Effects of Ellagic Acid against UVA-induced Oxidative Stress in Human Dermal Papilla

Purpose: One of solar radiation components, ultraviolet A (UVA), has deeply penetrating capacity and generates reactive oxygen species (ROS) in the skin. These characteristics arouse oxidative stress in dermis, such as photoproducts, senescence, cell death, inflammation, and alterative gene expression. Thus, UVA is considered a major factor of external stimuli that irritates the skin. This study aimed at investigating the antioxidant and anti-inflammatory effects of ellagic acid on UVAirradiated human dermal papilla cells (HDPCs). Methods: The cell viability of HDPCs were analyzed using the water-soluble tetrazolium salt (WST-1) assay. 2,7-dichlorofluorescin diacetate (DCFH-DA) was used in evaluating intracellular ROS scavenging activity. All the mRNA expression levels were carried out via quantitative real-time polymerase chain reaction (qRT-PCR). Cellular senescence was evaluated using senescence-associated -galactosidase (SA--gal) staining kit. The wound healing assay in HDPCs were performed to assess effects of ellagic acid on the cell migration activity. Results: No cell cytotoxicity of ellagic acid was observed at concentration up to 25 M. In irradiated HDPCs, ellagic acid showed protective effects on UVA-induced cytotoxicity. Further, ellagic acid represented ROS scavenging activity and regulating antioxidant gene expression, catalase transcriptional levels under UVAirradiated condition. It also modulated tumor necrosis factor alpha (TNF-) and interleukin 6 (IL-6) mRNA expresison levels and cellular senescence on UVA-stimulated HDPCs. Cell migration assay showed the protective effects of ellagic acid on movement of HDPCs damaged by UVA. Conclusion: These results demonstrate that ellagic acid protects UVA-induced oxidative stress in HDPCs.